The present study investigate the effects induced by the administration of the aqueous leaf stalk extract of Piper betel at the doses of 0.15 ml (50mg/kg/BW/day) on male mice for 10 to 50 days. This treatment causes significant increase in the anodic or negatively charged electrophoretic protein concentration in seminal plasma of mice, collected from cauda epididymis during 10, 20, (P<0.1), 30, 40 (P<0.01) &  50 days (P<0.001) of treatment than the control. This significant rise of anodic protein adds more negative charges on sperm surface membrane that inhibits capacitation and fertilizing ability of the sperm. M–isozymes of LDH (LDH4 and LDH5) also shows significant increase during 10 to 30 days (p<0.01) and highly significant during 40 and 50 days (p<0.001) of Piper betel leaf stalk treated mice than the control. Increased M –Isozymes causes significant increase in the total activity of LDH which suggests a shift in the tissue respiration from aerobic to anaerobic condition resulting more conversion of pyruvate into lactate. As a result there is more accumulation of lactate in the seminal plasma. Accumulated lactate in the seminal plasma of treated mice may cause decreased cellular respiration than the control, which adversely affect the sperm metabolism in the epididymis. It is concluded that the aqueous leaf stalk extract of Piper betel show antifertility effects in male mice by impairing capacitating power of spermatozoa due to rise in anodic protein and by altering sperm metabolism due to change in M- Isozyme pattern and thus helps in fertility regulation.

Keywords: Piper Betel Leaf Stalk, Anodic Electrophoretic Protein, M-Isozymes of LDH, Fertility Regulation.