Non-mutagenicity of capsaicin in albino mice.

Capsaicin, the active principle of red pepper, administered intraperitoneally to adult male mice at doses of 0.4, 0.8 or 1.6 mg/kg body weight/day (1/20, 1/10 or 1/5 of the LD50) on five consecutive days, did not induce any clinical signs of toxicity. No significant alterations were observed in epididymal weights, caudal sperm counts, testicular weights or testicular histology. In the sperm morphology assay, sperms at 1, 3, 5 and 7 wk did not reveal any treatment-related increase in the incidence of sperm-head abnormalities. Capsaicin also failed to induce dominant-lethal mutations during an 8-wk sequential mating schedule of males treated at the highest dose.