Tephrosin

Tephrosin is a rotenoid flavonoid derived primarily from Tephrosia vogelii and related leguminous plants, exerting anticancer activity chiefly through mitochondrial complex I inhibition and disruption of the PI3K/Akt/mTOR signaling axis. Preclinical research highlights its ability to suppress tumor growth and restore chemotherapy sensitivity in resistant cancer cell lines.

Origin & History

Tephrosin is a naturally occurring rotenoid compound extracted from plants in the Fabaceae family, particularly Tephrosia vogelii and Tephrosia purpurea. It is isolated from roots, leaves, or stems using organic solvents like methanol or ethanol, followed by chromatographic purification.

Historical & Cultural Context

While isolated tephrosin has no documented traditional medicinal use, the source plants like Tephrosia vogelii have been traditionally used in African systems primarily for piscicidal (fish-poisoning) purposes rather than internal medicine. The compound was historically noted for its toxicity to aquatic organisms.

Health Benefits

• Pancreatic cancer inhibition: Reduced tumor volume by up to 60.2% in mouse xenograft models (PMID: 33391424) - preclinical evidence only
• Ovarian cancer chemosensitization: Restored paclitaxel sensitivity in resistant SKOV3-TR cells with 36% apoptosis induction (PMID: 38137377) - in vitro evidence only
• Lung cancer suppression: Induced autophagic cell death via ROS and Hsp90 inhibition in A549 cells (PMID: 21061222) - in vitro evidence only
• Anti-inflammatory effects: Attenuated sepsis-induced acute lung injury in rat models (PMID: 29432911) - animal evidence only
• EGFR pathway modulation: Promoted EGFR internalization and degradation in cancer cells (PMID: 20056314) - in vitro evidence only

How It Works

Tephrosin inhibits mitochondrial NADH:ubiquinone oxidoreductase (Complex I), disrupting cellular energy metabolism and triggering reactive oxygen species (ROS)-mediated apoptosis in cancer cells. It also downregulates the PI3K/Akt/mTOR signaling pathway, suppressing anti-apoptotic proteins such as Bcl-2 and Bcl-xL while upregulating pro-apoptotic Bax. Additionally, in paclitaxel-resistant ovarian cancer cells, tephrosin modulates P-glycoprotein (P-gp) efflux pump activity and reverses multidrug resistance by altering MDR1 gene expression.

Scientific Research

No human clinical trials have been conducted with tephrosin; all evidence comes from preclinical studies. Key studies include a mouse xenograft model (PMID: 33391424) showing 60.2% tumor reduction with 10-20 mg/kg daily for 13 days, and in vitro work (PMID: 38137377) demonstrating restored chemosensitivity in resistant ovarian cancer cells at 1-10 µM concentrations.

Clinical Summary

All current evidence for tephrosin is preclinical, with no completed human clinical trials published as of 2024. In mouse xenograft models of pancreatic cancer, tephrosin administration reduced tumor volume by up to 60.2% compared to controls (PMID: 33391424). In vitro studies using paclitaxel-resistant SKOV3-TR ovarian cancer cells demonstrated that tephrosin co-treatment restored drug sensitivity and induced 36% apoptosis, suggesting chemosensitization potential (PMID: 38137377). The evidence base is limited to cell culture and rodent models, meaning efficacy and safety in humans remain entirely unestablished.

Nutritional Profile

Tephrosin is not a nutrient or food substance; it is a naturally occurring rotenoid isoflavonoid (chemical formula: C₂₃H₂₂O₇, molecular weight: ~410.42 g/mol) primarily isolated from plants of the genus Tephrosia (e.g., Tephrosia purpurea, Tephrosia vogelii) and related leguminous species. It has no conventional nutritional profile (no macronutrients, vitamins, minerals, fiber, or protein content) as it is studied exclusively as a bioactive phytochemical/pharmacological compound. Key biochemical characteristics: • Classification: Rotenoid isoflavonoid; structural analog of deguelin and rotenone. • Typical concentrations in source plants: Found in trace amounts (usually low mg/g range in dried root or leaf extracts; precise concentrations vary by species, part, and extraction method — e.g., approximately 0.01–0.5% w/w of crude root extract in Tephrosia spp.). • Core bioactive structure: Contains a cis-fused B/C ring junction characteristic of rotenoids, with hydroxyl and methoxy substituents that contribute to its biological activity including mitochondrial complex I inhibition and Hsp90 interaction. • Solubility/Bioavailability: Poorly water-soluble; lipophilic compound typically requiring organic solvents (DMSO, ethanol) for dissolution. Oral bioavailability in humans is not established; preclinical studies use intraperitoneal or direct cell-culture administration. Absorption, distribution, metabolism, and excretion (ADME) data in humans are currently unavailable. • Related co-occurring bioactives in Tephrosia extracts: deguelin, rotenone, tephrosin itself, and other rotenoids/flavonoids, which may exhibit synergistic or additive effects in crude preparations. • No established dietary reference intake, recommended daily allowance, or tolerable upper intake level exists, as tephrosin is an investigational compound, not a dietary supplement or food ingredient.

Preparation & Dosage

No clinically studied human dosages exist. Preclinical studies used: In vitro: 1-20 µM for 24-48 hours on cancer cell lines. In vivo (mice): 10-20 mg/kg intraperitoneally daily for 13 days. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Paclitaxel, 2-deoxy-D-glucose, ROS-inducing compounds, Hsp90 inhibitors, EGFR modulators

Safety & Interactions

Tephrosin has not been evaluated for safety in human clinical trials, and no established safe dosage range exists for human supplementation. As a rotenoid and mitochondrial Complex I inhibitor, it shares a mechanism class with rotenone, which has documented neurotoxicity in animal models at high doses, raising theoretical safety concerns. It may potentiate the effects of chemotherapeutic agents such as paclitaxel, meaning concurrent use with oncology drugs should only occur under direct medical supervision. Tephrosin is contraindicated during pregnancy and breastfeeding due to complete absence of safety data, and individuals with mitochondrial disorders should avoid it entirely.