Dietary choline, betaine and lecithin mitigates endosulfan-induced stress in Labeo rohita fingerlings.

A five-week experiment was conducted to delineate stress-mitigating effects of three different methyl donors in Labeo rohita fingerlings subjected to endosulfan toxicity. Four iso-nitrogenous and iso-caloric feed were prepared with and without supplementation of methyl donors. The feed were basal or control diet (i.e., without methyl donor supplementation), feed supplemented with choline, feed supplemented with betaine and feed supplemented with lecithin. Two hundred and twenty-five fishes were distributed randomly in five treatment groups each with three replicates. The experimental setup were normal water (without endosulfan) and fed with control diet (control group), endosulfan-treated water and fed with control diet (T1), endosulfan-treated water and fed with choline supplemented feed (T2), endosulfan-treated water and fed with betaine supplemented feed (T3) and endosulfan-treated water and fed with lecithin-supplemented feed (T4). The level of endosulfan in endosulfan treated water was maintained at the level of 1/10 of LC50, that is, 0.2 ppb. During the experiment, growth performances, metabolic enzyme activity and histological examination were done to assess the effect of treatments. The growth performance (percentage weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio) and nutrient digestibility were significantly different (P<0.01) in lecithin, betaine and choline fed group when compared to endosulfan-exposed group fed with basal diet. The liver LDH and MDH activity were significantly (P<0.01) improved in the groups fed with methyl donor supplemented diet. The liver AST and ALT, brain AChE and muscle ALT did not change with supplementation in the diet, but muscle ALT and G6PDH significantly (P<0.01) changed with supplementation. The gill and liver ATPase and intestinal ALP were significantly (P<0.01) noticeably changed in supplemented group. After endosulfan exposure, histopathology alter like slight large vacuolation in hepatocyte and lipoid vacuole were observed and with supplementation normal appearance of liver were observed. The chromosome aberration (karyotype) was observed in endosulfan-exposed group. The result obtained in present study concluded that inclusion of methyl donors, particularly lecithin and betaine, in feed as nutritional supplements has a potential stress-mitigating effect in L. rohita fingerlings.

Methyl donors potentiates growth, metabolic status and neurotransmitter enzyme in Labeo rohita fingerlings exposed to endosulfan and temperature.

A 2-month preliminary study was conducted to delineate the effect of dietary methyl donors (choline, betaine, and lecithin) on the growth performance and metabolic status of Labeo rohita fingerlings subjected to endosulfan alone and in combination with elevated temperature. Four iso-caloric and iso-nitrogenous diets viz. basal diet, betaine-supplemented diet, choline-supplemented diet and lecithin-supplemented diet were prepared and fed to the different experimental groups throughout the experimental period as per the design. Two hundred and seventy fingerlings (average weight 7.95 ± 0.04 g) were randomly distributed in six treatment groups each having three replicates. The experimental groups were as follows: fish subjected to normal water (without endosulfan) and fed with control diet (control group T(0)), fish subjected to endosulfan-treated water and fed with control diet (T(1)), fish subjected to concurrent exposure of endosulfan and elevated temperature and fed with control diet (T(2)), fish subjected to endosulfan and elevated temperature and fed with choline-supplemented diet (T(3)), fish subjected to endosulfan and temperature and fed with betaine-supplemented feed (T(4)), and fish subjected to endosulfan and temperature and fed with lecithin-supplemented feed (T(5)). The result shows that in both the groups, that is, endosulfan exposed and concurrent exposure to endosulfan and elevated temperature group of L. rohita the growth performance like percentage weight gain, feed conversion ratio and specific growth rates were significantly different (P < 0.01) when fed with supplemented diet compared with control fed group. The liver LDH and MDH activity were significantly lower in lecithin, betaine, and choline fed groups. The muscle AST as well as G6PDH, AST, and ALT did not vary but liver ALT, gill and liver ATPase, intestine ALP, muscle and liver glycogen varied significantly with dietary supplementation. The liver and gill glutathione-S-transferase (GST) activities were significantly lower in methyl donors-supplemented groups and brain AChE activity showed lower inhibition in supplemented groups in both endosulfan alone and concurrently exposed endosulfan and temperature groups. The result obtained in this study concludes that inclusion of methyl donors, particularly lecithin and betaine in feed as nutritional supplements have potential to improve growth and stress mitigating effect in L. rohita fingerlings.