Dietary vitamin-E modulates antioxidant defence system in giant freshwaterprawn, Macrobrachium rosenbergii

The objectives of the present study were to determine the effect of supplem entary vitamin-E (200, 400 and 600 mg/kg feed) on lipid peroxidation (LPX) and antioxidant defence system in gills and hepatopancreas of the freshwate r prawn, Macrabrachium rosenbergii. Results indicated that vitamin-E inhibi ted LPX in the hepatopancreas in a comparatively lower dose than gills. Sup eroxide dismutase (SOD) activity was decreased significantly in gills in re sponse to all the three supplemented diet, but in hepatopancreas decrease w as observed only in response to higher doses of vitamin-E (400 and 600 mg/k g feed). Catalase (CAT) activity was reduced significantly only in gills bu t not in hepatopancreas. While glutathione peroxidase (GPX) activity was si gnificantly elevated in the hepatopancreas by vitamin-E, its activity remai ns unaltered in gills. On the contrary, glutathione reductase (GR) activity was decreased in gills but that of hepatopancreas was constant. Glutathion e (GSH) content of both gills and hepatopancreas was substantially elevated in the vitamin-E supplemented prawns. Although the ascorbic acid (ASA) con tent of gills was unchanged by vitamin-E, its level elevated significantly in hepatopancreas. Thus the findings of the present investigation suggest t hat dietary vitamin-E is capable of reducing LPX level and can modulate ant ioxidant defence system in gills and hepatopancreas, nevertheless, the resp onse is highly tissue specific. It is further observed that highest dose of vitamin-E (600 mg/kg feed) could not render much additional protection in both the tissues. (C) 2000 Elsevier Science Inc. Pill rights reserved.