ANTIOXIDANT POTENTIAL OF Mn2+ IN THE HUMAN EJACULATED SPERMATOZOA UNDER OXIDATIVE STRESS

Reactive oxygen species (ROS) formation from fertile volunteer donor measured by thiobarbuteric acid reactive substances (TBARS). Spermatozoal suspension was treated or not with nicotine and supplemented or not with Mn2+. The same protocol followed when we used ferrous ascorbate promoter system and calculates the Cmax and kc value of the reaction using Lineweaver-burk double reciprocal plot. For comparing the antioxidant status Mn2+ with other trace elements employing various concentrations (10-100µM), production of malondialdehyde (MDA) calculated. Effect of lipid peroxidation (LPO) upon membrane integrity monitored by performing hypo-osmotic swelling test (HOS). Extent of LPO was measured for one-hour intervals of 10 minutes each, TBARS production found to increase gradually. Supplementation of Mn2+ to nicotine treated or not spermatozoal suspensions significantly lower the TBARS production in different concentration of promoter system (ferrous sulphate and ascorbic acid; 1:5). According to Michaelis-Menten kinetic it was observed that there was linear and positive correlation between amounts of malon-dialdehyde produced (vi) and increase in substrate concentration (S). Nicotine treated or not supplemented or not with Mn2+, ferrous ascorbate promoter system the value of kc was found to be 62.50µM FeSO4 and 312.5µM ascorbic acid. The value of Cmax was found to be lower in Mn2+ supplemented treated or not with nicotine as compare to Mn2+ unsupplemented, nicotine treated or not sample. Supplementation of different concentration trolox, Mn2+, Zn2+, Co2+ and Ni2+ to assay mixture, amount of TBA-MDA complex was monitored and data has been transferred to Dixon plot (I/v) vs. [I]. Values of ki of all trace metal were finding in the same order. The data follow a linear correlation with the Cmax value of the reaction. Hypo-osmotic swelling test also show the significant result. On the basis of Cmax, ki values and other parameter we can conclude that Mn2+ is the most potent trace metal ion inhibitor of LPO in the human ejaculated spermatozoal suspension