Silbinol (Pterocarpus marsupium)

Silbinol is a patented extract of Pterocarpus marsupium heartwood standardized to pterostilbene and epicatechin, bioactive compounds that activate AMPK signaling and modulate PPAR-gamma receptors to support healthy blood glucose metabolism. It has demonstrated antioxidant and anti-inflammatory activity in both preclinical models and human clinical trials, with measurable effects on glutathione levels and glycemic markers.

Origin & History

Silbinol is a standardized extract derived from the heartwood of Pterocarpus marsupium (Indian Kino Tree), standardized to contain 5%, 30%, or 90% pterostilbene by weight. The extract is obtained through standardization processes that concentrate the active pterostilbene while retaining other bioactive polyphenols and catechins naturally present in the plant material.

Historical & Cultural Context

Pterocarpus marsupium is referenced in Ayurveda, the traditional Indian system of medicine, indicating centuries of traditional application. The specific historical applications are not detailed in available sources, though the plant's inclusion in Ayurvedic practice suggests longstanding medicinal use.

Health Benefits

• Cardiovascular support through reduction of TMAO formation and vascular inflammation (preliminary evidence from animal studies)
• Antioxidant activity with 11.3% increase in glutathione levels from baseline (human clinical trial)
• Anti-inflammatory effects via suppression of TNF-α, E-selectin, and VCAM-1 genes (animal model evidence)
• Superior bioavailability and metabolic stability compared to resveratrol (mechanistic studies)
• Maintenance of normal blood sugar and metabolic parameters (human safety study)

How It Works

Silbinol's primary bioactives, pterostilbene and epicatechin, activate AMP-activated protein kinase (AMPK), which enhances peripheral glucose uptake and inhibits hepatic gluconeogenesis. Epicatechin additionally modulates PPAR-gamma, improving insulin sensitivity at the receptor level. The extract suppresses pro-inflammatory cytokines including TNF-alpha and E-selectin, and reduces TMAO formation by altering gut microbial enzyme activity, contributing to cardiovascular and metabolic benefits.

Scientific Research

A randomized, placebo-controlled safety evaluation (PMID: 37671486) tested 200 mg/day of standardized Pterocarpus marsupium extract (90% pterostilbene) in healthy adults, finding no adverse effects and maintenance of normal metabolic parameters. Additional preclinical research published in Molecular Nutrition and Food Research demonstrated cardiovascular benefits through microbiota regulation, though human efficacy trials remain limited.

Clinical Summary

A human clinical trial documented an 11.3% increase in glutathione levels from baseline following Silbinol supplementation, indicating measurable antioxidant efficacy. Anti-inflammatory outcomes including suppression of TNF-alpha and E-selectin have been observed, though some inflammatory data derive from animal or in vitro models rather than large-scale randomized controlled trials. Cardiovascular findings related to TMAO reduction are preliminary and primarily supported by animal study evidence. Overall, human clinical evidence is promising but limited in sample size and study duration, warranting larger RCTs to confirm glycemic and cardiovascular endpoints.

Nutritional Profile

Silbinol is a proprietary standardized extract of Pterocarpus marsupium (Indian Kino Tree) heartwood, not a conventional macronutrient source. Primary bioactive compounds: Pterostilbene (key active stilbenoid, structurally analogous to resveratrol with two methoxy groups instead of hydroxyl groups, enhancing lipophilicity and metabolic stability); Epicatechin (flavan-3-ol polyphenol); Pterosupin (a C-glycosylflavone); Marsupsin and Liquiritigenin (additional phenolic constituents). Pterostilbene is typically standardized to defined concentrations in Silbinol extracts, with bioavailability approximately 4-fold greater than resveratrol due to reduced first-pass metabolism and enhanced cellular uptake. Macronutrient content is negligible at typical supplemental doses (50–500 mg/day). No significant vitamins or minerals are contributed. Fiber content is minimal in extract form. The extract demonstrates enhanced metabolic stability with a plasma half-life approximately 7 times longer than resveratrol. Bioavailability is further supported by dimethyl ether substitution pattern, which reduces glucuronidation and sulfation reactions in hepatic metabolism, resulting in higher circulating parent compound concentrations. Antioxidant activity quantified at 11.3% increase in glutathione levels in human clinical data. No significant caloric contribution at standard doses.

Preparation & Dosage

Clinically studied dosage: 200 mg/day (100 mg twice daily) of standardized extract containing 90% pterostilbene. Alternative commercial standardizations exist at 5% and 30% pterostilbene, but lack specific human clinical dosing data. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Resveratrol, Quercetin, Berberine, Alpha-Lipoic Acid, Chromium

Safety & Interactions

Silbinol is generally well tolerated in studies, with no severe adverse events reported at standard supplemental doses, though comprehensive long-term safety data in humans remain limited. Because its constituents influence glucose metabolism, concurrent use with antidiabetic medications such as metformin, sulfonylureas, or insulin may produce additive hypoglycemic effects requiring medical supervision. Pterostilbene, a key bioactive, is a mild CYP2C9 inhibitor and may theoretically affect plasma levels of warfarin and other drugs metabolized by this enzyme. Safety during pregnancy and lactation has not been established, and use should be avoided in these populations without physician guidance.