Testosterone like activity of seeds of Mucuna pruriens and its effects on serum biochemical metabolites in immature male rats were investigated. Forty eight immature male rats were divided into four equal groups. Rats of groups A and B were orally given ethanolic and aqueous extracts of Mucuna pruriens seeds daily at the dose rate of 500 mg/kg body weight, respectively, for 14 days. Rats of group C were injected with testosterone at the dose rate of 2.5 mg/kg body weight daily, while rats of group D served as controls. After 7 days, six rats from each group were euthanized, while the remaining six rats from each group were euthanized after 14 days of treatment. Rats given ethanolic extract gained higher weight compared to controls (P<0.05). Testis weight was the highest in rats treated with testosterone. The effect of treatments on the weight of the liver and the kidneys was non significant. Rats given ethanolic or aqueous extract had higher serum testosterone concentration than controls. Similarly, rats given ethanolic or aqueous extract had higher serum total proteins, total cholesterol and HDL cholesterol compared to controls. Moreover, ethanolic extract treated rats also had higher total cholesterol and HDL cholesterol than aqueous extract treated rats. However, differences in serum total proteins, total cholesterol and HDL cholesterol between control and testosterone injected rats were non significant. Serum triglycerides, LDL cholesterol and ALT activity did not differ among rats of four groups. Serum AST activity and urea were lower in rats treated with ethanolic or aqueous extract compared to controls. Thus, seeds of Mucuna pruriens had testosterone like activity and increased serum total proteins, total cholesterol and HDL cholesterol, with no adverse effects on the serum LDL cholesterol, liver or kidney functions.

Key words: Biochemical metabolites, Immature rats, Mucuna pruriens, Serum, Testosterone