Silybin — Hermetica Encyclopedia
Named Bioactive Compounds · Compound

Silybin

Provisional Strong Scorecompound

Hermetica Superfood Encyclopedia

Evidence review status: unreviewed

Legacy index-continuity record: the score and narrative are provisional and must not be represented as validated or human-approved.

Review flags: AWAITING_SEMANTIC_VALIDATION

Provisional Summary

Silybin is the most bioactive flavonolignan compound in milk thistle extract, comprising 50-70% of silymarin complex. It functions as a potent hepatoprotective agent by stabilizing hepatocyte membranes and reducing oxidative stress through antioxidant pathways.

Screened PMID Records
Reported Benefits
Pending
Synergy Review
At a Glance
CategoryNamed Bioactive Compounds
GroupCompound
Public Score StatusProvisional Strong
Primary Keywordsilybin benefits
Silybin close-up macro showing natural texture and detail — rich in hepatoprotective, antioxidant, anti-inflammatory
Silybin — botanical close-up

Origin & History

Silybin growing in Mediterranean — natural habitat
Natural habitat

Silybin (also known as silibinin) is the major active flavonolignan constituent of silymarin, a standardized extract from the seeds of the milk thistle plant (Silybum marianum), a thistle native to the Mediterranean region. It is extracted via solvent-based methods from the plant's ripe seeds followed by purification, with standardized extracts containing 70-80% flavonolignans, of which silybin comprises about 50-60%.

Milk thistle (Silybum marianum) and its silymarin/silybin extracts have been used in traditional European herbal medicine for centuries to treat liver and gallbladder disorders. Historical use dates to ancient Greece, with the herb persisting in Western folk medicine specifically for hepatoprotection.Traditional Medicine

Research Narrative (Provisional)

Large Phase II trials in NASH patients (NCT00680407, PMID: 31536511; NCT02006498, PMID: 28419855) using 420-2100 mg/day silymarin showed no significant improvement in primary endpoints, though a meta-analysis (PMID: 29245314) found modest transaminase reductions. A triple-blind RCT in breast cancer patients (PMID: 33861657) suggested potential hepatoprotective effects during chemotherapy.

Preparation & Dosage

Dosage guidance is withheld because the publication gate has not recorded adequate support for this profile.

Nutritional Profile

Silybin is a pure bioactive flavonolignan compound, not a whole food, and therefore has no meaningful macronutrient, vitamin, mineral, or fiber profile in the traditional nutritional sense. Key compositional details: Silybin is the primary active constituent (~50-70%) of silymarin, the standardized extract from milk thistle (Silybum marianum) seeds. It exists as two diastereomers: Silybin A and Silybin B, with Silybin B generally showing greater biological activity. Molecular weight: 482.44 g/mol. As a flavonolignan, it combines a flavonoid (taxifolin) and a lignan (coniferyl alcohol) moiety. Typical therapeutic doses studied range from 94 mg to 576 mg/day of silybin equivalents. Bioavailability is a significant limiting factor: conventional silybin has poor oral bioabsorption (~0.73-1% in some models) due to low water solubility and limited intestinal permeability. Enhanced delivery forms show markedly improved bioavailability: Silybin-phosphatidylcholine complex (Siliphos/IdB 1016) demonstrates 4-10x greater absorption compared to standard silybin; nanoparticle and phytosome formulations further improve plasma concentrations. Peak plasma concentration (Cmax) in phosphatidylcholine complex formulations reached approximately 0.5-1.0 µg/mL at doses of 360 mg. Silybin undergoes hepatic phase II conjugation (glucuronidation and sulfation) and is primarily excreted via bile. No caloric contribution is expected at therapeutic doses.

Reported Mechanism (Provisional)

Mechanism of Action

Silybin stabilizes hepatocyte cell membranes by binding to phospholipids and preventing lipid peroxidation. It activates nuclear factor erythroid 2-related factor 2 (Nrf2) pathways to enhance antioxidant enzyme production including glutathione peroxidase and superoxide dismutase. The compound also inhibits nuclear factor kappa B (NF-κB) activation, reducing inflammatory cytokine production in liver tissue.

Clinical Narrative (Provisional)

A meta-analysis of 8 randomized controlled trials demonstrated silybin's efficacy in non-alcoholic fatty liver disease, reducing AST levels by 6.57 U/L and ALT levels by 9.16 U/L compared to placebo. One RCT in breast cancer patients showed reduced hepatic involvement on ultrasonography during chemotherapy treatment. Evidence quality is moderate for liver enzyme reduction but preliminary for chemotherapy-induced hepatotoxicity prevention. Most studies used silybin-phosphatidylcholine complexes at doses ranging from 376-800mg daily.

Also Known As

SilibininSilybum marianum extractMilk thistle flavonolignanSilybin ASilybin BHepatoprotective flavonoidSilymarin bioactive

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These statements have not been evaluated by the Food and Drug Administration. This content is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
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