Gossypetin

Gossypetin is a hexahydroxyflavone flavonoid found naturally in hibiscus flowers and roselle, distinguished by a hydroxyl group at the 8-position of its flavone backbone. It exerts anticancer and antioxidant effects primarily by inhibiting MKK3/MKK6 protein kinases and inducing apoptotic and autophagic cell death pathways.

Origin & History

Gossypetin is a hexahydroxyflavone flavonoid found naturally in the flowers and calyx of Hibiscus sabdariffa, commonly known as roselle. It is commercially available as a dark yellow powder with limited solubility in certain solvents.

Historical & Cultural Context

There are no documented historical or traditional medicinal uses of gossypetin in the sources provided. Its presence is noted as a natural plant metabolite.

Health Benefits

• Induces apoptosis and autophagic cell death in prostate cancer cells (in vitro evidence).
• Inhibits MKK3/MKK6 protein kinases, suppressing esophageal cancer growth (in vitro evidence).
• Attenuates the MKK3/6-p38 signaling pathway, offering potential anticancer activity (in vitro evidence).
• Exhibits antioxidant properties, contributing to cellular protection (in vitro evidence).
• Displays antibacterial activity, supporting potential therapeutic applications (in vitro evidence).

How It Works

Gossypetin inhibits the dual-specificity protein kinases MKK3 and MKK6, thereby suppressing downstream p38 MAPK signaling, a pathway involved in cancer cell proliferation and survival. It also triggers caspase-dependent apoptosis and beclin-1-mediated autophagic cell death in cancer cell lines, particularly prostate and esophageal cancer models. Additionally, its six hydroxyl groups confer potent free-radical scavenging activity by donating hydrogen atoms to reactive oxygen species, positioning it as a direct antioxidant compound.

Scientific Research

No human clinical trials, RCTs, or meta-analyses have been identified. The evidence is limited to in vitro studies; no PMIDs are available.

Clinical Summary

Research on gossypetin remains predominantly preclinical, with the bulk of evidence derived from in vitro cell culture studies using prostate cancer (LNCaP, PC-3) and esophageal cancer cell lines. These studies demonstrate dose-dependent suppression of tumor cell growth and induction of apoptosis, but no peer-reviewed human clinical trials have been published to date. Animal model data are limited and have not yet established effective or safe dosing ranges for humans. The overall evidence base is early-stage, and conclusions about efficacy in humans cannot be drawn from current data.

Nutritional Profile

Gossypetin is a pure polyphenolic flavonoid compound (specifically a flavonol), not a whole food ingredient, so conventional macronutrient or micronutrient profiling (calories, protein, fat, fiber) is not applicable. Molecular formula: C15H10O8; molecular weight: 318.23 g/mol. It is structurally characterized as 3,5,7,8,3',4'-hexahydroxyflavone, distinguished from quercetin by an additional hydroxyl group at the 8-position on the A-ring, which confers enhanced antioxidant radical-scavenging capacity. Gossypetin is naturally found in cottonseed (Gossypium species) flowers and hibiscus (Hibiscus sabdariffa) at trace concentrations typically in the range of 0.1–2 mg/g dry weight of plant material, often occurring as glycosides (e.g., gossypetrin, gossypetin-3-glucoside). Bioactive concentration as an isolated compound in experimental studies typically ranges from 10–100 µM in in vitro models. Bioavailability: As a free aglycone, intestinal absorption is limited due to poor aqueous solubility; glycosylated forms may improve bioavailability via intestinal hydrolysis by beta-glucosidases. No established dietary reference intake or recommended dose exists. It does not contribute meaningful vitamins, minerals, fiber, or macronutrients as an isolated compound.

Preparation & Dosage

No clinically studied dosage ranges are available, as there are no human trials documented. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Curcumin, Quercetin, Resveratrol, Green tea extract, Vitamin C

Safety & Interactions

No established safe dosage range for gossypetin in humans has been defined through clinical trials, making supplementation guidance speculative. Because gossypetin inhibits p38 MAPK signaling, theoretical interactions exist with immunosuppressants, chemotherapy agents, and anti-inflammatory drugs that share overlapping pathways. Its potent antioxidant activity may also interfere with pro-oxidant chemotherapy regimens if taken concurrently. Pregnant or breastfeeding individuals should avoid gossypetin supplementation entirely due to the complete absence of human safety data.