ABSTRACT

Reproductive performance is a key factor affecting farm profitability. There is claim on the use of aerial part of Phyllanthus amarus to improve fertility, by traditional medicine practitioners. Based on this traditional belief or folklore, this research is designed to investigate the effect of ethanoilic leaf extract of this plant on the reproductive indices of mature rabbits bucks. The ethanolic extract of Phyllanthus amarus was tested for its acute toxicity effects in mice. Twenty (20) rabbit bucks were randomly distributed into 5 groups; (A-E). Groups A and E were the negative and positive controls respectively while groups B,C, D were the treatment groups that receives 50, 100 and 200 mg/kg body weight of the extract respectively. The extract was administered via intragastric with the help of gavage for forty four (44) days. Statistical analyses were performed using Graph pad (prism) statistical software. The LD50 for the ethanolic extract of Phyllanthus amarus was calculated to be 5000 mg/kg body weight. The Phyllanthus amarus extract significantly (p<0.05) increased the haemoglobin, white blood cell count, and the various red blood cell indices. Phyllanthus amarus significantly (p<0.05) altered all the serum biochemical parameters evaluated in this study. Phyllanthus amarus significantly increased the serum level of superoxide dismutase and catalase in a dose dependent manner across the treated groups compared to the untreated group, the serum level of glutathione and Malondialdhyde showed no significant (p>0.05) difference between the treated groups and the untreated group. The semen parameters such as semen volume, progressive motility, spermatozoa live proportion, spermatozoa concentration, total number of spermatozoa per ejaculate and total viable spermatozoa were significantly (p<0.05) higher in the rabbit bucks administered with the least dose (50 mg/kg body weight) of Phyllanthus amarus ethanolic extract compared to rabbit bucks that received 100 and 200 mg/kg respectively. The plant extract had significant (p<0.05) effect on the morphology of the spermatozoa. The highest (13.50 ± 0.11 %) total abnormal spermatozoa was observed in the 200 mg/kg group, whereas the vitamin E treated group  recorded the least (5.00 ± 0.11 %) total abnormal spermatozoa when compared with the extract group (p<0.5). The rabbit bucks administered with the least (50 mg/kg body weight) dose of Phyllanthus amarus recorded the highest (6.96 ± 0.14 ng/ml) testosterone concentration, although this value was comparable to the reference drug (6.04 ± 1.20 ng/ml). The outcome of the research shows that the leaves of P. amarus does significantly contribute directly to the claim by traditional medical practitioner on the use of this plant to increase male fertility potentials, with an indirect beneficial effect to this claim; such as antioxidant activity and the hormone (testosterone) booster effect which mimics vitamin E in both activity and possibly, mechanism of action, The study also revealed that increasing the herbal dose of the ethanol extract of P. amarus beyond 100 mg/kg is capable of altering the antioxidant milieu of the testes resulting in oxidative stress in testes which could probably lead to compromised testicular function as observed.