Question 1

How does Tephrosia vogelii work as an insecticide and parasiticide?

Accepted Answer

Tephrosia vogelii contains rotenone, tephrosin, and deguelin, which act as potent mitochondrial inhibitors. Rotenone disrupts cellular respiration by blocking electron transport in mitochondria, leading to cellular energy depletion and death. This mechanism explains its traditional use as a fish poison and insecticide. The same compounds affect parasites like lice, scabies mites, and intestinal worms by disrupting their cellular energy production. Evidence level: C—preliminary studies and traditional use support these mechanisms, though clinical trials in humans are limited.

Question 2

Does Tephrosia vogelii interact with any medications?

Accepted Answer

There is limited research on specific drug interactions for Tephrosia vogelii. Because rotenone affects mitochondrial function and cellular metabolism, theoretical interactions could occur with medications metabolized by the liver or drugs affecting cellular respiration. Due to its toxicity profile and lack of safety data, Tephrosia vogelii should not be combined with pharmaceutical medications. Evidence level: C. Given the potential for severe toxicity, avoid concurrent use with any medications and consult a qualified healthcare provider before any application.

Question 3

What is the correct dosage of Tephrosia vogelii?

Accepted Answer

Tephrosia vogelii should only be used topically as a leaf paste or preparation applied to affected skin areas. Internal ingestion is dangerous and can cause severe toxicity, including respiratory paralysis and death. There is no established safe oral dosage. For external use on skin conditions like scabies or fungal infections, traditional preparations involve crushing fresh leaves into a paste applied for limited periods. Evidence level: C. Always wash off thoroughly after application and discontinue if skin irritation develops. Do not use on broken skin or open wounds.

Question 4

Is Tephrosia vogelii safe during pregnancy and breastfeeding?

Accepted Answer

Tephrosia vogelii is unsafe during pregnancy and breastfeeding. The rotenone and related compounds can cross biological membranes and may cause fetal harm or be excreted in breast milk. Traditional knowledge and animal studies suggest significant toxicity risks. Pregnant and breastfeeding women should avoid all forms of Tephrosia vogelii, including topical applications, as compounds may be absorbed through the skin. Evidence level: C. There are no circumstances where use during pregnancy is considered acceptable. Women of childbearing age should use effective contraception if exposure is possible.

Question 5

What is Tephrosia vogelii used for medicinally?

Accepted Answer

Tephrosia vogelii has been used traditionally in East African medicine for treating scabies, lice, intestinal parasites, and various skin infections. The plant's insecticidal and parasiticidal properties come from compounds like rotenone, tephrosin, and deguelin. Historically, it was also used as a fish poison for harvesting fish from ponds and streams. Current evidence level is C, meaning traditional use is well-documented but clinical trials are lacking. Modern applications focus primarily on external treatment of parasitic skin conditions. Internal use is not recommended due to toxicity concerns.

Question 6

What are the side effects and toxicity risks of Tephrosia vogelii?

Accepted Answer

Tephrosia vogelii carries significant toxicity risks, particularly if ingested. Internal use can cause nausea, vomiting, respiratory paralysis, and potentially death due to rotenone's effects on cellular respiration. Topical application may cause skin irritation, redness, or contact dermatitis in sensitive individuals. The plant is contraindicated for children, pregnant women, and anyone with compromised health. Evidence level: C. There is no safe internal dose. Even external use requires caution—avoid application to broken skin, mucous membranes, or near the eyes. Seek immediate medical attention if ingestion occurs.

Tephrosia Vogelii

Sources & Citations

Guarea guidonia

Artemisia pallens

Gaillardia aristata

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Evidence summary

PubMed sources

Government sources