Tag: MONOGRAPH

  • MitoQ

    Plain-language summaryIntrigue 75 / 100

    MitoQ is mitochondria-targeted ubiquinone (a derivative of CoQ10 with a positively charged triphenylphosphonium group that drives accumulation in mitochondria). Concentrates antioxidant activity at the mitochondrial inner membrane where oxidative damage occurs. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Mitochondria-targeted ubiquinone-derived antioxidant conjugated to a triphenylphosphonium cation

    A synthetic coenzyme Q10 analog covalently linked to a lipophilic triphenylphosphonium moiety that drives selective mitochondrial accumulation, enabling targeted quenching of reactive oxygen species at the inner mitochondrial membrane with demonstrated vascular, hepatoprotective, and anti-inflammatory activity in human clinical studies.

    Abstract

    Mitoquinone mesylate (MitoQ) is a mitochondria-targeted antioxidant composed of a ubiquinone moiety covalently linked via a ten-carbon alkyl chain to a triphenylphosphonium (TPP+) cation, enabling rapid permeation of lipid bilayers and accumulation within the mitochondrial matrix at concentrations up to several hundred-fold above extracellular levels, driven by the large negative mitochondrial membrane potential (approximately negative 150 to negative 180 millivolts). The compound was developed in the 1990s by Robin Smith and Michael Murphy at the University of Otago, New Zealand, as an approach to overcoming the failure of conventional untargeted antioxidants (including native coenzyme Q10) to achieve therapeutically meaningful concentrations within mitochondria, the principal intracellular source of reactive oxygen species (ROS). Within the mitochondrion, MitoQ adsorbs to the matrix-facing leaflet of the inner mitochondrial membrane, where the ubiquinone head group is reduced to the active antioxidant ubiquinol form by complex II (succinate:ubiquinone oxidoreductase) of the electron transport chain. The ubiquinol form scavenges superoxide, hydroxyl radicals, and peroxyl radicals, preventing lipid peroxidation of cardiolipin and other mitochondrial membrane phospholipids. Following oxidation during radical quenching, the resulting ubiquinone is re-reduced by complex II, establishing a catalytic antioxidant cycle that permits repeated radical neutralization from a single molecule. This recycling mechanism distinguishes MitoQ from stoichiometric antioxidants such as alpha-tocopherol that are consumed in the quenching reaction. Preclinical pharmacology has demonstrated protective effects in rodent models of ischemia-reperfusion injury, diabetic nephropathy, nonalcoholic fatty liver disease, sepsis-associated organ failure, pulmonary hypertension, Alzheimer’s disease, doxorubicin-induced cardiomyopathy, cisplatin nephrotoxicity, and metabolic syndrome, with consistent reductions in mitochondrial oxidative damage markers, preservation of mitochondrial membrane potential, and attenuation of downstream inflammatory signaling through suppression of NF-kappaB activation and NLRP3 inflammasome assembly. Four completed human clinical trials define the current clinical evidence base. The Snow et al. (2010) PROTECT study, a 12-month randomized double-blind placebo-controlled trial in 128 newly diagnosed untreated Parkinson’s disease patients at 40 or 80 mg per day, found no difference between MitoQ and placebo on any measure of disease progression, establishing an important negative result for the oxidative stress hypothesis in early Parkinson’s disease. The Gane et al. (2010) phase II trial in 30 patients with chronic hepatitis C virus infection demonstrated significant decreases in serum alanine aminotransferase and aspartate aminotransferase at 40 and 80 mg per day over 28 days, without change in viral load, suggesting hepatoprotective activity through reduction of mitochondrial oxidative necroinflammation. The Rossman et al. (2018) randomized crossover trial in 20 healthy older adults (60 to 79 years) with impaired endothelial function demonstrated that 6 weeks of MitoQ at 20 mg per day produced a 42 percent improvement in brachial artery flow-mediated dilation versus placebo, with concurrent reductions in plasma oxidized low-density lipoprotein and aortic pulse wave velocity, establishing the first human evidence for mitochondria-targeted antioxidant improvement of age-related vascular dysfunction. A 2024 exploratory pilot trial (Jain et al. 2024) of MitoQ as post-exposure prophylaxis against SARS-CoV-2 infection reported reduced infection rates and symptom duration in the treatment group versus matched controls. The compound is well tolerated in human studies at doses up to 80 mg per day for 12 months, with nausea and gastrointestinal discomfort as the principal dose-limiting adverse events. MitoQ is not approved as a pharmaceutical by any regulatory authority; it is marketed globally as a dietary supplement at doses of 5 to 10 mg per day and is available as a research-grade compound from multiple chemical suppliers. This monograph reviews the chemistry, synthesis, and mitochondrial targeting mechanism of MitoQ; the comprehensive preclinical pharmacology across disease models; the complete human clinical evidence base; pharmacokinetics including the low oral bioavailability and extensive first-pass metabolism; sourcing, reconstitution, and handling; stack-interaction considerations; adverse-event signal; and a structured comparative assessment of five mitochondria-targeted antioxidant candidates (SkQ1, elamipretide, MitoTEMPO, MitoVitE, idebenone) against MitoQ on five competency standards.

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  • Blarcamesine

    Sigma-1 receptor agonist and mixed muscarinic receptor modulator (aminotetrahydrofuran derivative)

    An orally bioavailable aminotetrahydrofuran derivative developed by Anavex Life Sciences as a sigma-1 receptor agonist with muscarinic receptor co-activity, investigated for disease modification in Alzheimer’s disease, Rett syndrome, Parkinson’s disease dementia, and other neurodegenerative and neurodevelopmental conditions.

    Abstract

    Blarcamesine (ANAVEX 2-73; tetrahydro-N,N-dimethyl-2,2-diphenyl-3-furanmethanamine) is a small-molecule sigma-1 receptor (SIGMAR1) agonist and mixed muscarinic acetylcholine receptor modulator that has advanced through Phase 2b/3 clinical development for early Alzheimer’s disease, Phase 3 for adult Rett syndrome, Phase 2 for Parkinson’s disease dementia, and Phase 2/3 for pediatric Rett syndrome. The compound was first characterized pharmacologically by Villard, Espallergues, Keller, Vamvakides, and Maurice (2011) as a novel aminotetrahydrofuran derivative with anti-amnesic and neuroprotective activity mediated through dual engagement of sigma-1 and muscarinic acetylcholine receptors. The sigma-1 receptor is an endoplasmic reticulum chaperone protein localized at mitochondria-associated endoplasmic reticulum membranes (MAMs) that modulates calcium homeostasis, endoplasmic reticulum stress responses, mitochondrial function, autophagy, and neuroinflammation. Activation of SIGMAR1 by blarcamesine restores cellular proteostasis, reduces oxidative stress through suppression of reactive oxygen species, and promotes neuroplasticity through downstream modulation of brain-derived neurotrophic factor and glutamate signaling. In preclinical models, blarcamesine has demonstrated anti-amnesic activity in scopolamine- and dizocilpine-induced learning impairment paradigms, neuroprotection in the amyloid-beta(25-35) peptide injection mouse model of Alzheimer’s disease (blocking both cognitive impairment and hippocampal oxidative stress), amelioration of motor, sensory, and autonomic phenotypes in the Mecp2 mouse model of Rett syndrome, and dose-dependent sigma-1 receptor occupancy confirmed by positron emission tomography with the selective ligand [18F]FTC-146. The pivotal ANAVEX2-73-AD-004 Phase 2b/3 randomized, double-blind, placebo-controlled trial enrolled 508 patients with early Alzheimer’s disease across 52 centers in five countries and demonstrated that oral blarcamesine at 50 mg and 30 mg daily significantly slowed cognitive decline on the primary endpoint ADAS-Cog13 at 48 weeks (38.5% and 34.6% slowing versus placebo, respectively; P = 0.021 and P = 0.026) [1]. Co-primary analysis showed significant benefit on CDR-SB. Volumetric magnetic resonance imaging demonstrated significant reduction of whole brain atrophy by 37.6%, total grey matter atrophy by 63.5%, and lateral ventricular enlargement by 25.1% versus placebo. Plasma amyloid-beta 42/40 ratio increased significantly in the blarcamesine group (P = 0.048). Open-label extension data through four years of continuous treatment demonstrated sustained benefit on ADAS-Cog13 and ADCS-ADL, with a delayed-start analysis suggesting importance of early treatment initiation. The AVATAR Phase 3 trial in 33 adult patients with Rett syndrome (MECP2 mutation-positive) met primary (RSBQ AUC, P = 0.037; Cohen’s d = 1.91) and secondary (ADAMS, P = 0.010; CGI-I, P = 0.037) efficacy endpoints on once-daily oral dosing of up to 30 mg [2]. A proof-of-concept Phase 2 trial in 132 patients with Parkinson’s disease dementia showed dose-dependent cognitive improvement on the CDR computerized assessment system and improvement on MDS-UPDRS total score at 14 weeks [3]. The EXCELLENCE Phase 2/3 pediatric Rett syndrome trial in 92 patients showed numerical improvement in RSBQ but did not achieve statistical separation from placebo, possibly due to a high placebo response rate [4]. The safety profile across clinical programs is characterized by predominantly mild-to-moderate adverse events concentrated during the initial dose titration period. The most common treatment-emergent adverse events are dizziness (approximately 36% of treated patients in the Alzheimer’s disease program), confusional state (approximately 14%), balance disorder, and fatigue; these are generally transient (resolving within 7 to 11 days), manageable by titration schedule adjustment, and not associated with serious or life-threatening sequelae. No neuroimaging-related adverse events (such as amyloid-related imaging abnormalities) have been reported. Long-term safety data through four years of continuous dosing have not revealed new safety signals. The European Medicines Agency accepted a Marketing Authorization Application for blarcamesine in Alzheimer’s disease in December 2024, but the Committee for Medicinal Products for Human Use issued a negative opinion in December 2025 on grounds of insufficient demonstration of efficacy in patients without SIGMAR1 gene mutations and concerns regarding tolerability-driven treatment discontinuation. The application was subsequently withdrawn in March 2026. This monograph reviews the chemistry, structural class, and synthesis of blarcamesine; the sigma-1 receptor and muscarinic receptor pharmacology; the pharmacokinetic profile including the ANAVEX19-144 metabolite; the preclinical evidence base across Alzheimer’s, Rett syndrome, fragile X syndrome, and Parkinson’s disease models; the full clinical evidence base; sourcing considerations; reconstitution and handling; stack interactions; adverse events; and a comparative assessment of five sigma-1 receptor-active compounds against blarcamesine on five competency standards.

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  • Piperlongumine

    Electrophilic alpha,beta-unsaturated delta-valerolactam alkaloid amide with pro-oxidant and multi-target anticancer activity

    A naturally occurring cinnamoyl-dihydropyridinone amide alkaloid isolated from Piper longum L. (long pepper) with selective pro-oxidant cytotoxicity toward transformed cells, multi-pathway anticancer pharmacology spanning ROS accumulation, GSTP1 and TrxR1 inhibition, NF-kB suppression, STAT3 antagonism, PI3K/Akt/mTOR pathway downregulation, and NLRP3 inflammasome blockade, and emerging senolytic activity against radiation-induced and replicative senescent fibroblasts.

    Abstract

    Piperlongumine (piplartine, 5,6-dihydro-1-[(2E)-1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)-pyridinone; CAS 20069-09-4; molecular formula C17H19NO5; molecular weight 317.34 g/mol) is an amide alkaloid constituent of the fruit, root, and stem of Piper longum L. (long pepper), a plant of the Piperaceae family native to the Indian subcontinent and Southeast Asia with a centuries-long history of use in Ayurvedic and traditional Chinese medicine. The compound was first isolated and structurally characterized by Chatterjee and Dutta in 1963 and remained a minor phytochemical curiosity until the landmark 2011 report by Raj et al. in Nature, which identified piperlongumine through an unbiased chemical screen as a small molecule that selectively kills cancer cells and oncogene-transformed cells but not normal cells by inducing the accumulation of reactive oxygen species (ROS), irrespective of p53 status or proliferation rate [1]. That demonstration catalyzed an extensive preclinical research literature that now spans more than two dozen cancer histologies, multiple molecular targets, and several emerging non-oncologic applications including senolytic clearance of senescent cells, neuroinflammation, and metabolic disease.

    The molecular pharmacology of piperlongumine centers on its electrophilic alpha,beta-unsaturated carbonyl system, which reacts covalently with nucleophilic cysteine residues on multiple redox-regulatory and signaling proteins. Direct binding targets include glutathione S-transferase pi 1 (GSTP1), thioredoxin reductase 1 (TrxR1), and carbonyl reductase 1 (CBR1), whose inhibition impairs cellular antioxidant defenses and elevates intracellular ROS (principally hydrogen peroxide and superoxide) to levels that exceed the already elevated oxidative baseline of transformed cells [1, 2, 3]. Downstream consequences include ROS-dependent downregulation of specificity protein transcription factors Sp1, Sp3, and Sp4 and their pro-oncogenic target genes (cyclin D1, survivin, cMyc, EGFR, cMet) [4]; inhibition of the NF-kB signaling pathway with suppression of pro-inflammatory and pro-survival gene expression [5, 6]; direct inhibition of STAT3 phosphorylation and dimerization [7]; inhibition of PI3K/Akt/mTOR signaling with consequent promotion of autophagy and apoptosis [8, 9]; and blockade of NLRP3 inflammasome assembly through disruption of NLRP3-NEK7 association and NLRP3 oligomerization [10]. The compound has also been identified as a ligand for the orphan nuclear receptor NR4A1 (Nur77) [11]. The selectivity for cancer cells over normal cells is attributed to the higher basal ROS burden and the greater dependence on antioxidant buffering capacity in transformed cells; normal cells, operating at lower oxidative stress, tolerate the moderate ROS elevation induced by piperlongumine without reaching the apoptotic threshold.

    Pharmacokinetic characterization in rodent models indicates oral bioavailability of approximately 50 to 76 percent (dose-dependent, inversely related to dose in the 5 to 10 mg/kg range in rats), low hepatic extraction ratio (E = 0.09), plasma protein binding of approximately 93 percent, and metabolism by multiple CYP isoenzymes producing several hydroxylated and demethylated metabolites [12, 13]. The compound exhibits poor aqueous solubility (approximately 26 micrograms per milliliter in water at ambient pH) but adequate solubility in dimethyl sulfoxide, ethanol, PEG 400, and lipid-based formulations. Stability is pH-dependent, with maximum stability near pH 4 and significant degradation at alkaline pH values and under ultraviolet irradiation [14]. No human pharmacokinetic data have been published; the compound has not entered formal clinical trials as of the most recent monograph revision, though the extensive preclinical evidence base and favorable rodent safety profile support advancement to first-in-human studies.

    In vivo antitumor efficacy has been demonstrated in xenograft models of colorectal, pancreatic, lung, breast, head and neck, thyroid, prostate, and cervical cancers at intraperitoneal doses of 2.4 to 10 mg/kg per day, with significant tumor growth inhibition and no apparent systemic toxicity to normal tissues in treated animals [1, 15, 16, 17, 18]. Synergistic combinations with conventional chemotherapeutics (cisplatin, gemcitabine, paclitaxel, oxaliplatin, doxorubicin, 5-fluorouracil) have been reported across multiple tumor types, with the ROS-elevating mechanism of piperlongumine sensitizing resistant cells to cytotoxic therapy [19, 20, 21]. A second application of growing interest is the senolytic activity first reported by Wang et al. (2016), who demonstrated that piperlongumine selectively kills radiation-induced, replicative, and oncogene-induced senescent human WI-38 fibroblasts and synergizes with the BH3 mimetic ABT-263 in senescent cell clearance [22]. Subsequent medicinal chemistry optimization has produced piperlongumine analogs with up to 50-fold enhanced senolytic potency [23].

    This monograph documents the chemistry, isolation, and synthesis of piperlongumine; the multi-target molecular pharmacology; the rodent pharmacokinetic profile; the preclinical antitumor and senolytic evidence base; the absence of clinical trial data and the translational considerations for first-in-human development; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event and safety signal from animal studies; and a structured comparative assessment of five pro-oxidant or senolytic natural products (withaferin A, sulforaphane, parthenolide, curcumin, fisetin) against piperlongumine on five competency standards.

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    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Fisetin

    Plain-language summaryIntrigue 78 / 100

    Fisetin is a natural flavonoid found in strawberries and apples that selectively kills senescent cells (a senolytic). Mayo Clinic researchers identified it in screens looking for natural compounds with senolytic activity. Clinical trials are ongoing. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Flavonol polyphenol with senolytic, anti-inflammatory, and neuroprotective activity

    A naturally occurring 3,7,3′,4′-tetrahydroxyflavone identified as one of the most potent flavonoid senolytics, with convergent activity across PI3K/Akt/mTOR inhibition, SIRT1 activation, NF-kappaB suppression, and Nrf2-mediated antioxidant defense, positioned at the intersection of aging biology, neurodegeneration, and cancer chemoprevention research.

    Abstract

    Fisetin (3,7,3′,4′-tetrahydroxyflavone) is a bioactive flavonol found at highest dietary concentration in strawberries and at lower levels in apples, persimmons, grapes, onions, and cucumbers. First isolated from the heartwood of Venetian sumac (Cotinus coggygria) in the late nineteenth century and characterized as a plant pigment, fisetin remained a minor flavonoid of limited pharmacological interest until convergent twenty-first-century discoveries established it as a multi-target agent active across the principal molecular pathways of cellular senescence, neurodegeneration, inflammation, and oncogenesis. The compound was identified as a potent senolytic in the landmark Zhu et al. (2017) screen at the Mayo Clinic Robert and Arlene Kogod Center on Aging, and the subsequent Yousefzadeh et al. (2018) demonstration that late-life oral fisetin administration extended median and maximum lifespan in wild-type mice while reducing senescence-associated markers in multiple tissues positioned it as the leading dietary flavonoid candidate for translational senolytic therapy [1, 2]. Mechanistically, fisetin operates through a convergent multi-pathway pharmacology: it inhibits PI3K/Akt/mTOR signaling by direct suppression of PI3K catalytic and regulatory subunit expression and by activation of the mTOR repressor TSC2 through concurrent AMPK phosphorylation; it activates SIRT1-dependent deacetylation cascades that suppress NF-kappaB transcriptional activity and the senescence-associated secretory phenotype (SASP); it induces Nrf2 nuclear translocation and downstream phase II antioxidant enzyme expression; and it modulates the Bcl-2 family balance toward pro-apoptotic signaling selectively in senescent cells [3, 4, 5]. The neuroprotective profile has been extensively characterized by the Maher laboratory at the Salk Institute for Biological Studies, where fisetin and its optimized derivative CMS121 have demonstrated efficacy in transgenic Alzheimer’s disease mouse models through reduction of lipid peroxidation via fatty acid synthase (FASN) inhibition, suppression of neuroinflammatory cascades, and maintenance of glutathione homeostasis [6, 7]. CMS121 completed a Phase 1 clinical trial in 2025, with single doses up to 1800 mg and repeat doses up to 900 mg per day for 7 days demonstrating acceptable tolerability and favorable pharmacokinetic parameters in healthy volunteers [8]. The anticancer pharmacology spans preclinical efficacy in prostate, breast, colorectal, lung, melanoma, pancreatic, and bladder cancer models, principally through cell cycle arrest at G2/M and G1/S checkpoints, mitochondrial apoptosis induction, and suppression of epithelial-mesenchymal transition and matrix metalloproteinase expression [9, 10]. Clinical translation is constrained by the poor oral bioavailability characteristic of hydroxylated flavonols: fisetin undergoes rapid and extensive phase II conjugation (glucuronidation and sulfation) in the intestinal epithelium and liver, producing low systemic free flavonol concentrations after oral dosing; multiple formulation strategies (nanocochleates, liposomes, nanoemulsions, hybrid hydrogels) have demonstrated 10- to 140-fold bioavailability enhancement in preclinical and early human pharmacokinetic studies [11, 12]. Clinical trials led by the Kirkland laboratory at Mayo Clinic are evaluating fisetin at oral doses of 20 mg/kg per day for senolytic indications including frailty in aging (AFFINITY trial, NCT03675724), COVID-19 in skilled nursing facilities, and sepsis in elderly patients (STOP-Sepsis, NCT05758246) [13, 14]. This monograph reviews the chemistry, natural sourcing, and structural pharmacology of fisetin; the multi-pathway molecular mechanism across senescence, inflammation, neuroprotection, and oncogenesis; the pharmacokinetic limitations and formulation solutions; the preclinical evidence base across aging, neurodegeneration, and cancer; the clinical trial landscape; sourcing and quality verification for research applications; reconstitution and handling; stack interactions; adverse-event signal; and a comparative assessment of five senolytic or flavonoid candidates against fisetin on five competency standards.

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  • Boswellic-Acid

    Pentacyclic triterpenic acid from Boswellia serrata oleogum resin with selective 5-lipoxygenase inhibition and pleiotropic anti-inflammatory activity

    A family of ursane- and oleanane-type pentacyclic triterpenes isolated from Boswellia serrata frankincense resin, distinguished by noncompetitive allosteric inhibition of 5-lipoxygenase and convergent anti-inflammatory activity through NF-kappaB suppression, topoisomerase inhibition, and leukotriene biosynthesis blockade.

    Abstract

    Boswellic acids are a family of pentacyclic triterpenic acids isolated from the oleogum resin (frankincense) of Boswellia serrata and related species (B. carterii, B. sacra, B. papyrifera) that have been used in Ayurvedic medicine for centuries under the name Salai guggal and are now recognized as pharmacologically active anti-inflammatory agents with a distinct mechanism of action centered on selective, noncompetitive, allosteric inhibition of 5-lipoxygenase (5-LOX). The family comprises four principal bioactive congeners: beta-boswellic acid (beta-BA), 11-keto-beta-boswellic acid (KBA), 3-O-acetyl-beta-boswellic acid (ABA), and 3-O-acetyl-11-keto-beta-boswellic acid (AKBA), with AKBA representing the most potent 5-LOX inhibitor (IC50 approximately 1.5 micromolar in human neutrophils) and the primary pharmacologically characterized congener. The 5-LOX inhibition by AKBA proceeds through an allosteric, nonredox, noncompetitive mechanism that is unique among clinically studied leukotriene synthesis inhibitors and distinguishes the boswellic acid class from both the redox-type 5-LOX inhibitors (zileuton) and the competitive cysteinyl leukotriene receptor antagonists (montelukast, zafirlukast). Beyond 5-LOX inhibition, boswellic acids exert convergent anti-inflammatory activity through suppression of NF-kappaB signaling via direct inhibition of IkappaB kinases (IKKalpha and IKKbeta), inhibition of human leukocyte elastase, inhibition of topoisomerases I and IIalpha, modulation of complement system activation, and suppression of proinflammatory cytokine release including tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6. Pharmacokinetics in humans are characterized by poor oral bioavailability of the keto-boswellic acids (KBA and AKBA) attributable to extensive first-pass hepatic metabolism via CYP3A4-mediated hydroxylation and carboxylesterase 2-mediated deacetylation, with plasma elimination half-lives of approximately 6 hours. Concomitant administration with a lipid-rich meal substantially improves absorption. Clinical evidence from randomized controlled trials supports efficacy in osteoarthritis (pain reduction and functional improvement at 100 to 250 mg AKBA-enriched extract daily), bronchial asthma (improvement in 70 percent of patients at 300 mg three times daily), inflammatory bowel disease (Crohn’s disease and ulcerative colitis, with response rates comparable to mesalazine), and radiation-induced cerebral edema (greater than 75 percent edema reduction in 60 percent of patients at 4200 mg daily). The compound class is generally well tolerated, with the principal adverse events being mild gastrointestinal discomfort (nausea, acid reflux, diarrhea) and rare allergic dermatitis. This monograph reviews the chemistry, structural pharmacology, and biosynthesis of the boswellic acid family; the multi-target mechanism of action in molecular detail; the comprehensive human pharmacokinetic record including bioavailability enhancement strategies; the clinical evidence base across osteoarthritis, asthma, inflammatory bowel disease, cerebral edema, and oncology-supportive indications; sourcing and quality verification considerations; reconstitution and handling; stack-interaction implications; adverse-event signal; and a comparative assessment of five alternative anti-inflammatory natural compounds against boswellic acids on five competency standards.

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  • Pirenzepine

    Selective M1 muscarinic acetylcholine receptor antagonist of the pyridobenzodiazepinone structural class

    A peripherally selective, M1-preferring muscarinic antagonist developed at Dr. Karl Thomae GmbH (Boehringer Ingelheim) as a gastric antisecretory agent for peptic ulcer disease, subsequently investigated as a topical ophthalmic intervention for the retardation of progressive myopia in children.

    Abstract

    Pirenzepine (LS 519, Gastrozepin) is a tricyclic pyridobenzodiazepinone and the prototypical selective antagonist of the M1 subtype of the muscarinic acetylcholine receptor. Synthesized at Dr. Karl Thomae GmbH, a subsidiary of Boehringer Ingelheim, in the mid-1970s, the compound was the first muscarinic antagonist demonstrated to discriminate pharmacologically between what were subsequently classified as M1 and M2 receptor subtypes, a finding reported by Hammer et al. in 1980 in Nature and foundational to the modern subtype classification of muscarinic receptors [1]. Pirenzepine binds the M1 muscarinic receptor with a dissociation constant (Ki) of approximately 5 to 14 nanomolar and displays 5- to 20-fold selectivity over the M2, M3, and M5 subtypes, with intermediate affinity at M4 receptors [2, 3]. The compound is peripherally selective, exhibiting negligible penetration of the blood-brain barrier at therapeutic oral doses, a property that minimizes central anticholinergic adverse effects and distinguishes it from atropine and other non-selective muscarinic antagonists. The primary registered indication is peptic ulcer disease. Pirenzepine inhibits vagally mediated and pentagastrin-stimulated gastric acid secretion through antagonism of M1 receptors on intramural gastric plexus neurons, reducing basal acid output by approximately 50 percent at oral doses of 50 mg twice daily [4, 5]. Extensive controlled trials conducted through the late 1970s and 1980s demonstrated duodenal ulcer healing rates of 60 to 76 percent at 4 to 8 weeks on pirenzepine 100 to 150 mg per day, broadly comparable to cimetidine 1 g per day and superior to placebo and gefarnate [6, 7]. The compound was registered as Gastrozepin in numerous European, Asian, and Latin American jurisdictions but was never approved by the United States Food and Drug Administration. The clinical importance of pirenzepine as a gastric antisecretory agent has diminished substantially following the introduction of histamine H2 receptor antagonists and proton pump inhibitors, which offer superior acid suppression and ulcer healing rates. A second, more recent research application is the retardation of progressive myopia (axial elongation of the globe) in children aged 8 to 12 years. Two multicenter, randomized, double-masked, placebo-controlled trials of 2% pirenzepine ophthalmic gel, conducted by Siatkowski et al. (2004, 2008), demonstrated approximately 50 percent reduction in the rate of myopia progression over 1- and 2-year treatment periods, with a clinically acceptable safety profile dominated by mild pupil dilation and accommodation difficulty [8, 9]. The mechanism of the antimyopic effect is incompletely characterized but is attributed to M1 and possibly M4 muscarinic receptor antagonism in the retina and sclera, modulating signaling cascades that regulate scleral extracellular matrix remodeling and axial elongation [10]. The ophthalmic application has not received regulatory approval; the compound remains investigational for myopia control, with atropine (a non-selective muscarinic antagonist applied at low concentrations) having advanced further in clinical development for this indication. Pharmacokinetics are characterized by low oral bioavailability (20 to 30 percent in fasted subjects, further reduced by food), a plasma elimination half-life of approximately 10 to 12 hours, negligible hepatic first-pass metabolism, predominant renal elimination of unchanged drug, and low plasma protein binding (approximately 12 percent) [11, 12]. The compound does not undergo significant cytochrome P450-mediated metabolism and has a correspondingly limited drug-drug interaction profile. The principal adverse events at registered oral doses are mild anticholinergic effects: dry mouth (approximately 14 percent), blurred vision (1 to 5 percent, dose-dependent), and constipation (approximately 3 percent), with an overall discontinuation rate of approximately 2 percent in controlled trials [6]. Serious adverse events are rare. This monograph reviews the chemistry, synthesis, and structural pharmacology of pirenzepine; the molecular pharmacology at muscarinic receptor subtypes; comprehensive human pharmacokinetics; the clinical evidence base across peptic ulcer and myopia indications; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event signal; and a structured comparative assessment of five gastric antisecretory and muscarinic antagonist alternatives (telenzepine, atropine, cimetidine, ranitidine, omeprazole) against pirenzepine on five competency standards.

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  • Apigenin

    Trihydroxyflavone with multi-target activity spanning CD38 NADase inhibition, GABA-A receptor modulation, aromatase suppression, and broad anti-inflammatory and pro-apoptotic signaling

    A dietary flavone abundant in chamomile, parsley, and celery, distinguished from other common flavonoids by potent CD38 NADase inhibition with consequent elevation of intracellular NAD+, moderate GABA-A receptor activity at the benzodiazepine site, competitive aromatase inhibition, and a broad preclinical pharmacology spanning anti-inflammatory, neuroprotective, anti-cancer, and metabolic endpoints.

    Abstract

    Apigenin (4′,5,7-trihydroxyflavone) is a naturally occurring flavone present at high concentration in chamomile flowers, parsley, celery, and numerous other dietary plant sources. It is one of the most extensively studied plant flavonoids, with a preclinical research literature encompassing anti-inflammatory, antioxidant, neuroprotective, anxiolytic, anti-cancer, cardioprotective, and metabolic activities. The compound is distinguished from the structurally related flavonoids quercetin, luteolin, and kaempferol by several pharmacological features of particular current research interest: potent inhibition of CD38, the principal mammalian NAD+-degrading ectoenzyme, resulting in elevation of intracellular nicotinamide adenine dinucleotide (NAD+) and consequent activation of sirtuin-dependent deacetylation pathways relevant to metabolic syndrome and aging; moderate activity at the benzodiazepine binding site of the gamma-aminobutyric acid type A (GABA-A) receptor, producing anxiolytic and sedative effects in rodent models; competitive inhibition of aromatase (CYP19A1) with an IC50 of approximately 20 to 23 micromolar, reducing estrogen biosynthesis; and suppression of NF-kappaB-driven proinflammatory cytokine production through multiple converging mechanisms including direct IKK-beta inhibition and modulation of the PI3K/AKT and MAPK/ERK signaling cascades.

    The CD38 inhibitory activity, formally characterized by Escande et al. (2013) in a report from the Bhatt, Chini, and Sinclair laboratories, demonstrated that apigenin administration to obese mice increased tissue NAD+ levels, decreased global protein acetylation through sirtuin activation, and improved glucose and lipid homeostasis parameters [1]. This finding positioned apigenin within the NAD+ restoration research framework alongside nicotinamide mononucleotide and nicotinamide riboside, though through a mechanistically distinct pathway (reduced NAD+ degradation rather than precursor supplementation). The GABA-A receptor activity, first reported by Viola et al. (1995) using competitive radioligand displacement at the benzodiazepine site, produced anxiolytic effects in elevated plus maze and open field paradigms in mice without the sedation, amnesia, or muscle relaxation characteristic of classical benzodiazepines [2]. Subsequent electrophysiological and behavioral studies have produced conflicting characterizations of the precise nature of the GABA-A interaction, with reports variously describing apigenin as a weak partial agonist, an antagonist, or an inverse agonist at the benzodiazepine site depending on assay system and concentration.

    Pharmacokinetics in humans are incompletely characterized. Oral bioavailability is estimated at approximately 30 percent, limited by poor aqueous solubility and extensive first-pass phase II conjugation (glucuronidation and sulfation). Phase I oxidative metabolism is mediated principally by CYP1A1, CYP1A2, and CYP2E1, producing the hydroxylated metabolite luteolin as the major oxidative product. The plasma elimination half-life after oral administration is approximately 2 to 3 hours in the limited human pharmacokinetic data available. Apigenin inhibits CYP2C9, CYP3A4, and P-glycoprotein in vitro at concentrations that may be clinically relevant at supplemental doses, raising drug-drug interaction considerations.

    The compound is non-mutagenic and non-genotoxic in standard regulatory toxicology assays. No significant toxicity has been observed in animal studies at doses up to 50 mg/kg, though hepatotoxicity has been reported at intraperitoneal doses of 100 mg/kg and above in mice. Human safety data at supplemental doses (50 to 500 mg daily) are limited but have not produced serious adverse event signals. The principal reported adverse effects at supplemental doses are drowsiness (consistent with GABA-A activity) and mild gastrointestinal discomfort.

    This monograph reviews the chemistry, natural sources, and isolation history of apigenin; the multi-target molecular pharmacology spanning CD38, GABA-A, aromatase, and inflammatory signaling; the available pharmacokinetic data in animals and humans; the preclinical pharmacology across neuroprotective, anti-cancer, anti-inflammatory, and metabolic endpoints; the limited clinical evidence base; sourcing and quality verification for research applications; reconstitution and handling; stack interactions; adverse events and safety; and a comparative assessment of five structurally or functionally related flavonoid compounds against apigenin on five competency standards.

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    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Dihydro-NMN

    Reduced pyridine nucleotide and potent NAD+ precursor of the dihydronicotinamide mononucleotide class

    A reduced-form nicotinamide mononucleotide that bypasses canonical salvage pathway enzymes to elevate cellular NAD+ and NADH more rapidly and to a greater extent than its oxidized counterpart NMN, with emerging preclinical evidence in renal cytoprotection, metabolic reprogramming, and anti-proliferative activity.

    Abstract

    Dihydronicotinamide mononucleotide (NMNH), also designated reduced nicotinamide mononucleotide or dihydro-NMN, is the 1,4-dihydropyridine analog of beta-nicotinamide mononucleotide (NMN). The compound differs from NMN by a single additional hydrogen at the C-4 position of the nicotinamide ring, converting the aromatic pyridinium to a non-aromatic 1,4-dihydropyridine and conferring distinct biochemical, pharmacokinetic, and pharmacological properties. NMNH was first characterized as a potent nicotinamide adenine dinucleotide (NAD+) precursor in mammalian systems in two independent 2021 reports: Zapata-Perez et al. in The FASEB Journal demonstrated that NMNH increases NAD+ levels to a substantially greater extent and faster than NMN or nicotinamide riboside (NR) across multiple tissues in mice, while Liu et al. in the Journal of Proteome Research showed that NMNH potently enhances NAD+ and NADH, suppresses glycolysis and the tricarboxylic acid cycle, induces reductive stress, and inhibits cell growth in hepatocellular carcinoma cells. The metabolic pathway of NMNH is mechanistically distinct from that of NMN: NMNH is converted directly to NADH by nicotinamide mononucleotide adenylyltransferase (NMNAT) without requiring nicotinamide phosphoribosyltransferase (NAMPT) or nicotinamide riboside kinase (NRK), the two rate-limiting enzymes of the canonical salvage and Preiss-Handler pathways. The resulting NADH is then oxidized to NAD+ by cellular oxidoreductases, producing a net elevation of both reduced and oxidized pyridine dinucleotide pools. In vivo, intraperitoneal administration of NMNH to mice elevates hepatic NAD+ approximately five-fold and renal NAD+ approximately two-fold, with significant increases also observed in brain, skeletal muscle, brown adipose tissue, and heart, tissues in which equivalent doses of NMN produce no statistically significant NAD+ elevation. The Zapata-Perez et al. study additionally demonstrated that NMNH protects conditionally immortalized proximal tubular epithelial cells against hypoxia and reoxygenation injury, reducing expression of the kidney injury biomarker Kim-1 and the mitochondrial dysfunction marker Tfam, establishing a preclinical basis for renal cytoprotection. The Liu et al. metabolomic analysis revealed that NMNH-treated cells exhibit marked suppression of glycolytic intermediates (glucose-6-phosphate, fructose-1,6-bisphosphate, phosphoenolpyruvate, pyruvate) and tricarboxylic acid cycle intermediates (citrate, alpha-ketoglutarate, succinate, fumarate, malate), accompanied by cell cycle arrest and growth inhibition. The compound induces cellular reductive stress through elevation of the NADH/NAD+ ratio, which paradoxically increases reactive oxygen species (ROS) production, linking the reductive stress phenotype to the anti-proliferative activity. NMNH is prepared by chemical reduction of NMN with thiourea dioxide in alkaline aqueous solution or by enzymatic cleavage of NADH with NADH pyrophosphatase (NudC). The compound is supplied as the disodium salt (CAS 108347-85-9) and is commercially available from multiple research chemical suppliers. A first-in-human clinical trial reported in January 2026 indicated that oral NMNH at 500 mg daily for 90 days approximately tripled circulating NAD+ levels in healthy adults, though these results remain unpublished and unverified by independent peer review. No regulatory approval exists for NMNH in any jurisdiction; the compound is sold as a dietary supplement or research reagent. This monograph reviews the chemistry, synthesis, and structural distinction from NMN; the NMNAT-dependent metabolic pathway; the preclinical pharmacology across NAD+ elevation, renal cytoprotection, metabolic reprogramming, and anti-proliferative activity; the limited pharmacokinetic data in mice and humans; the emerging clinical evidence; sourcing and quality verification; reconstitution and handling; stack interactions with other NAD+ precursors and metabolic modulators; the adverse-event and safety signal including reductive stress and reactive oxygen species concerns; and a comparative assessment of five NAD+ precursor candidates against NMNH on five competency standards.

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    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Urolithin A

    Plain-language summaryIntrigue 78 / 100

    Urolithin A is a natural compound produced by gut bacteria from pomegranate, walnuts, and berries. It induces mitophagy, the process of cleaning out damaged mitochondria. Amazentis sells a clinical-grade form as Mitopure. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Dibenzo[b,d]pyranone mitophagy inducer derived from gut microbial metabolism of dietary ellagitannins

    A naturally occurring benzo[c]chromenone produced by human gut microbiota from ellagitannin precursors, identified as the first dietary metabolite to induce mitophagy through the PINK1/Parkin pathway in human skeletal muscle at oral doses, with clinical evidence in age-related mitochondrial decline, muscle function, immune senescence, and emerging neuroprotective applications.

    Abstract

    Urolithin A (3,8-dihydroxy-6H-dibenzo[b,d]pyran-6-one) is a dibenzopyranone metabolite produced by the human gut microbiota through sequential dehydroxylation of ellagic acid, itself the hydrolysis product of dietary ellagitannins found in pomegranates, walnuts, raspberries, and strawberries. The compound was first characterized as a bioactive ellagitannin metabolite in human plasma and urine by the Tomas-Barberan and Espin laboratories at CEBAS-CSIC (Murcia, Spain) in the early 2000s and was subsequently identified by the Auwerx laboratory at the Ecole Polytechnique Federale de Lausanne (EPFL) as a potent, first-in-class inducer of mitophagy in Caenorhabditis elegans and in mammalian systems through the PINK1/Parkin-dependent mitochondrial quality control pathway. The seminal Ryu et al. (2016) report in Nature Medicine demonstrated that urolithin A extends lifespan in C. elegans, improves exercise capacity in aged rodents, and induces a molecular signature of mitophagy in skeletal muscle, establishing the compound as the first dietary metabolite with demonstrated mitophagy-inducing activity at physiologically achievable concentrations [1]. Amazentis SA (Lausanne, Switzerland) subsequently developed a synthetic, pharmaceutical-grade form of urolithin A (marketed as Mitopure) and advanced the compound through a series of randomized, placebo-controlled clinical trials in human subjects. The first-in-human trial (Andreux et al. 2019, Nature Metabolism) demonstrated safety, oral bioavailability, and upregulation of mitochondrial gene expression in skeletal muscle of 60 healthy elderly subjects at doses of 250 to 2000 mg administered over 28 days [2]. A subsequent four-month randomized trial in 88 middle-aged adults (Singh et al. 2022, Cell Reports Medicine) demonstrated significant improvement in muscle strength (approximately 12 percent increase in hamstring muscle strength) and exercise performance at 500 mg and 1000 mg daily doses, with concurrent improvement in plasma biomarkers of mitochondrial health [3]. A parallel randomized trial (Liu et al. 2022, JAMA Network Open) in 66 older adults confirmed improvement in muscle endurance at 1000 mg daily over four months [4]. Most recently, a 2025 randomized trial (Singh et al. 2025, Nature Aging) in 50 healthy middle-aged adults demonstrated that 1000 mg daily urolithin A for four weeks expanded peripheral naive-like CD8+ T cell populations, reduced markers of T cell exhaustion, and increased CD8+ fatty acid oxidation capacity, establishing the first clinical evidence of urolithin A activity on immune senescence [5]. The molecular pharmacology of urolithin A extends beyond mitophagy induction to include activation of AMP-activated protein kinase (AMPK), inhibition of mechanistic target of rapamycin (mTOR), activation of sirtuin 1 (SIRT1) with consequent deacetylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1alpha) to promote mitochondrial biogenesis, suppression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) signaling with reduction of proinflammatory cytokines, and inhibition of dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) relevant to Alzheimer’s disease pathology. Pharmacokinetics in humans are characterized by intestinal absorption followed by extensive hepatic phase II conjugation (glucuronidation and sulfation), producing circulating glucuronide and sulfate conjugates with peak plasma concentrations at approximately 6 to 8 hours and elimination half-lives of 17 to 24 hours for the predominant glucuronide species. The compound received Generally Recognized as Safe (GRAS) status from the United States Food and Drug Administration in 2018 (GRN 000791) at dietary intake levels up to 1000 mg per serving. Preclinical safety assessment established a no-observed-adverse-effect level (NOAEL) of 3451 mg/kg/day in male rats and 3826 mg/kg/day in female rats in a 90-day oral toxicity study, with no evidence of genotoxicity or mutagenicity. This monograph reviews the chemistry, endogenous biosynthesis, and chemical synthesis of urolithin A; the multi-target molecular pharmacology encompassing mitophagy, mitochondrial biogenesis, anti-inflammatory, and neuroprotective mechanisms; the human pharmacokinetic profile including interindividual variability driven by gut microbiome metabotype; the clinical evidence base across muscle function, immune health, and emerging neurodegenerative and cardiometabolic indications; sourcing and quality verification for research applications; reconstitution and handling; stack interaction considerations; adverse-event profile; and a structured comparative assessment of five mitochondrial-targeted compounds against urolithin A on five competency standards.

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  • SRT2104

    Plain-language summaryIntrigue 50 / 100

    SRT2104 is a small-molecule sirtuin 1 (SIRT1) activator developed at Sirtris Pharmaceuticals (later acquired by GSK). It was designed as a more potent and drug-like successor to resveratrol, the natural compound that started the sirtuin-aging story. Sirtuins are NAD+-dependent enzymes that deacetylate metabolic and stress-response targets, hypothesized to mediate calorie-restriction-like longevity effects. SRT2104 activates SIRT1 allosterically and produced metabolic and inflammatory benefits in mouse studies. Phase 2 trials in diabetes, ulcerative colitis, and cardiovascular disease showed modest signals at best, and GSK shut down Sirtris in 2013 amid skepticism about the sirtuin-activator concept. Of mainly historical interest as a flagship compound of a faded program. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Selective small-molecule allosteric activator of NAD-dependent protein deacetylase sirtuin 1 (SIRT1)

    A second-generation imidazothiazole-scaffold sirtuin 1 activator developed by Sirtris Pharmaceuticals and advanced through multiple Phase 2 clinical programs by GlaxoSmithKline, distinguished from first-generation sirtuin-activating compounds by high target selectivity and favorable oral pharmacokinetics.

    Abstract

    SRT2104 (GSK2245840) is a synthetic, orally bioavailable, small-molecule allosteric activator of the NAD-dependent protein deacetylase sirtuin 1 (SIRT1, silent mating type information regulation 2 homolog 1), developed at Sirtris Pharmaceuticals and subsequently advanced into clinical trials by GlaxoSmithKline following the 2008 acquisition of Sirtris for approximately 720 million United States dollars. The compound is a second-generation sirtuin-activating compound (STAC) built on an optimized imidazo[2,1-b]thiazole scaffold and is reported to activate SIRT1 deacetylase activity approximately 1000-fold more potently than the natural polyphenol resveratrol in fluorophore-tagged peptide substrate assays, with minimal activity against a panel of more than 180 non-SIRT1 targets including kinases, G-protein-coupled receptors, nuclear receptors, ion channels, enzymes, and transporters [1, 2]. The allosteric mechanism involves binding to the N-terminal domain of SIRT1, lowering the Michaelis constant (Km) for the acetylated protein substrate without competing with either the NAD cofactor or the substrate acetyl-lysine site [3]. Downstream consequences of SIRT1 activation by SRT2104 include deacetylation and functional modulation of the transcription factor p53, the RelA/p65 subunit of nuclear factor kappa B (NF-kB), forkhead box protein O3 (FOXO3), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1alpha), and signal transducer and activator of transcription 3 (STAT3), producing composite anti-inflammatory, metabolic, and cytoprotective effects that have been characterized across a broad range of preclinical disease models [4, 5].

    Pharmacokinetics in humans are characterized by oral absorption with time to peak plasma concentration of 1 to 3 hours after single dosing, a terminal elimination half-life of 8 to 24 hours depending on dose, and substantial inter-individual variability that is not dose-proportional across the studied range of 0.03 to 3.0 grams [6]. The variable and non-dose-proportional pharmacokinetic profile has been identified as a principal limitation of the compound for clinical development in its current oral formulation. SRT2104 is poorly soluble in water and is formulated as a lipid-based oral capsule to improve bioavailability.

    Clinical evaluation has spanned at least seven registered clinical trials across multiple indications. In a Phase 1 trial in healthy elderly volunteers (60 to 80 years of age), 28 days of oral SRT2104 at 0.5 or 2.0 grams daily produced reductions in serum cholesterol, low-density lipoprotein, and triglycerides, with trends toward improved mitochondrial oxidative phosphorylation capacity as measured by phosphorus-31 magnetic resonance spectroscopy of skeletal muscle [7]. A Phase 2 randomized, placebo-controlled trial in 37 subjects with type 2 diabetes mellitus treated for 28 days at doses of 0.25, 0.5, 1.0, or 2.0 grams daily did not demonstrate improved glycemic control but produced a statistically significant reduction in total cholesterol and triglycerides at the 1.0 gram dose [8]. A separate cardiometabolic study in type 2 diabetic subjects reported trends toward improved endothelial function and arterial stiffness [9]. A Phase 2 trial in 40 subjects with moderate to severe psoriasis treated for 84 days at escalating doses of 250, 500, or 1000 milligrams daily reported 35 percent of SRT2104-treated patients achieving good to excellent histological improvement on skin biopsy, but three serious adverse events were reported including pneumonitis and pancreatitis [10]. A trial in mild to moderate ulcerative colitis (31 subjects, 50 or 500 milligrams daily for 8 weeks) demonstrated tolerability but limited clinical efficacy, with only 3 of 26 evaluable subjects achieving endoscopic remission [11]. In a human endotoxemia model, SRT2104 pretreatment significantly reduced lipopolysaccharide-induced cytokine release (interleukin-6, interleukin-8) and coagulation activation, representing the first human demonstration of anti-inflammatory and anticoagulant activity consistent with pharmacological SIRT1 activation [12].

    Preclinical pharmacology is extensive. The Mercken et al. (2014) study at the National Institute on Aging demonstrated that SRT2104 extends both mean and maximum lifespan of male mice fed a standard diet by 9.7 percent and 4.9 percent respectively, with preserved bone mineral density, muscle mass, motor coordination, and insulin sensitivity [13]. The Jiang et al. (2014) study demonstrated blood-brain barrier penetration, attenuation of brain atrophy, improvement of motor function, and extension of median lifespan by approximately 16 percent in N171-82Q Huntington disease model mice [14]. Additional preclinical evidence spans emphysema, sepsis, neonatal white matter injury, microglia polarization, dendritic outgrowth, and auditory cell senescence. GlaxoSmithKline discontinued active clinical development of SRT2104 following the 2013 closure of the Sirtris unit, though the compound remains widely used as a reference SIRT1 activator in academic and preclinical research. This monograph reviews chemistry, molecular pharmacology, pharmacokinetics, the complete clinical evidence base, sourcing and handling, stack interactions, adverse events, and a comparative assessment of five SIRT1 modulators against SRT2104 on five competency standards.

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