Effects of beta-carotene, selenium and vitamin A on in vitro polymorphonuclear leukocytic activity in peripartal buffalo (Bubalus bubalus)

The effect of different concentrations of three antioxidan s on phagocytic and kill activities of blood polymorphonuclear leukocytes (PMN) isolated fr om buffaloes during the peripartum period (4 weeks before to 7 weeks after parturition) was investigated in this study. Two concentrations of beta -ca rotene 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 (1 0(-6) M) significantly enhanced (P < 0.05) after parturition (Week 0 until Week 3), whereas the kill activity of the same cells significantly (P < 0.0 5) 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 o f 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 ac tivity 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 en hanced phagocytic activity of PMN at Weeks 0, 1, and 2, whereas, the concen tration 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 sele nium 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 selen ium. Apparently, the in vitro killing activity of PMN is a distinctive func tion from phagocytosis and both activities may be enhanced by the use of es sential nutrients, especially during the peripartum period. Moreover, beta -carotene is more effective as an antioxidant than vitamin A in enhancing t he activities of phagocytic cells. (C) 2001 by Elsevier Science Inc.