Dose- and time-dependent effects of ethanolic extract of Mucuna pruriens Linn. seed on sexual behaviour of normal male rats

Abstract

Aim of the study: According to Indian Systems of Medicine, Mucuna pruriens Linn., belonging to the leguminous family (Papilionaceae), were used for treating male sexual disorders since ancient times. In this study, the effects of ethanolic extracts of the Mucuna pruriens Linn. seed on general mating behaviour, libido and potency of normal male Wister albino rats were investigated and also compared with the standard reference drug, Sildenafil citrate.

Materials and methods: Animals were divided into one control group (Group I--received saline) and four experimental groups (Groups II-V). Experimental groups were divided on the basis of the dosage of extract to the animals as follows: 150 mg/kg body weight (Group I), 200mg/kg body weight (Group II) and 250 mg/kg body weight (Group IV) while Group V received Sildenafil citrate (5mg/kg body weight). Animals were fed PO with saline or extract or standard drug once in a day for 45 days. To analyse the mating behaviour, female rats with oestrus phase were used.

Results: The extract administered PO significantly increased the mounting frequency, intromission frequency and ejaculation latency, and decreased the mounting latency, intromission latency, post-ejaculatory interval and inter-intromission interval. The potency test significantly increased erections, quick flips, long flips and total reflex. Therefore, the results indicated that the ethanolic extracts of Mucuna pruriens Linn. seed produced a significant and sustained increase in the sexual activity of normal male rats at a particular dose (200mg/kg). When compared to control, all the drug-treated groups have shown drug-induced effects for a few parameters. However in Group II, there was an obvious enhancement in all parameters, without affecting the normal behaviour. When compared with the standard drug, the net effect of extract is even less than that in Group II.

Conclusions: Therefore, the resulting aphrodisiac activity of the extract lends support to the claim that it has traditionally been used for the treatment of sexual disorders.