In vitro effects of singular or combined anti-oxidative vitamins and/or minerals on tilapia (Oreochromis hybrids) peripheral blood monocyte-derived, anterior kidney-derived, and spleen-derived macrophages.

The present study was to determine the in vitro effects of singular or combined anti-oxidative vitamins (A, C, and E) and/or minerals (Se, Zn, Cu, Mn, and Fe) on the immune functions of tilapia, Oreochromis hybrids, peripheral blood monocyte-derived, anterior kidney-derived, and spleen-derived macrophages. An optimal dose of vitamins and minerals increased cell viability and lysozyme activity. On the other hand, the above activities decreased at the high doses of combined vitamins (A+C+E group, each 300 microg mL(-1)) or single mineral (Se, Zn, Cu, Mn, and Fe groups, each 200, 800 or 1000 microg mL(-1)). Combining two of the aforementioned vitamins (A+C, A+E, and C+E groups, each 100 microg mL(-1)) was able to prolong cell viable time up to 72 h compared with singular vitamin addition. Before or after adding vitamins or minerals during infection, addition of vitamins decreased the percentage of dead cells and a greater effect was observed for mineral (each 40 or 80 microg mL(-1)) and vitamin (each 100 microg mL(-1)) combinations. A low dose of vitamins increased nitric oxide production and decreased superoxide production, but high dose of vitamins decreased superoxide and nitric oxide productions. Furthermore, minerals also decreased nitric oxide production at concentrations of 40, 80, 200, 800 or 1000 microg mL(-1). The threshold concentrations for cell death by necrosis and/or apoptosis were >1000 and >800 microg mL(-1) for vitamins and minerals, respectively. In conclusion, appropriate concentration of vitamins or minerals can increase tilapia macrophage immunity; nevertheless, extreme concentrations of vitamins or minerals are lethal to cells.