Effects of beta-carotene, selenium and vitamin A on in vitro polymorphonuclear leukocytic activity in peripartal...

The effect of different concentrations of three antioxidans on phagocytic and kill activities of blood polymorphonuclear leukocytes (PMN) isolated from buffaloes during the peripartum period (4 weeks before to 7 weeks after parturition) was investigated in this study. Two concentrations of beta-carotene and vitamin A (10(-6) and 10(-5) M) and one concentration of Se (10(-9) M) were used. Phagocytic activity of PMN treated with beta-carotene (10(-6)M) significantly enhanced (P < 0.05) after parturition (Week 0 until Week 3), whereas the kill activity of the same cells significantly (P < 0.05) increased before and after parturition (at Weeks -4, -3, -2, 0, 1, 2 and 3). The concentration of beta-carotene (10(-5) M) enhanced phagocytosis of PMN only at Weeks 0 and 1 and kill activity at Weeks -4, -3, -2, 0, and 1. Selenium (10(-9)M) significantly (P < 0.05) enhanced phagocytic activity of PMN starting from parturition (Week 0) until Week 3 postpartum. Kill activity increased significantly both before (Weeks -4, -3 and -2) and after (Weeks 0, 1, 2, 3 and 4) parturition. Vitamin A (10(-6) M) significantly enhanced phagocytic activity of PMN at Weeks 0, 1, and 2, whereas, the concentration of beta-carotene (10(-5) M) increased phagocytic activity only at Week 0. Kill activity of PMN increased significantly (P < 0.05) at Weeks -1 and 0 (10(-6)M). These results demonstrate that beta-carotene and selenium significantly enhanced phagocytic and kill activities of PMN isolated from buffaloes around parturition in vitro. Vitamin A enhanced phagocytosis and kill activities but not to the same extent as beta-carotene and selenium. Apparently, the in vitro killing activity of PMN is a distinctive function from phagocytosis and both activities may be enhanced by the use of essential nutrients, especially during the peripartum period. Moreover, beta-carotene is more effective as an antioxidant than vitamin A in enhancing the activities of phagocytic cells.