Cynodon dactylon methanol extract potentiates stress mitigation in response to acidic stress in Labeo calbasu fingerlings

Abstract

A 30-day feeding trial was conducted to study the antistress ability of dietary Cynodon dactylon methanol extract against acid stress in Labeo calbasu fingerlings. Fish fingerlings (average weight 5.57±0.04 g) were randomly distributed into 4 groups; each with 3 replicates were fed with either of 4 diets containing different levels of C. dactylon methanol extract (0, 0.05, 0.5 or 5%). The possible antistress ability of C. dactylon methanol extract was assessed in terms of serum cortisol, serum glucose, serum cholesterol, serum alanine amino transferase (ALT), serum aspartate amino transferase (AST), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), ATPase, superoxide dismutase (SOD), catalase (CAT) and Glutathione S transferase by exposing to acidic water with pH 5.5 for 24 h. The serum cortisol level was significantly higher in the acid stress group than that in without acid stress counterpart. However, gradual supplementation of C. dactylon methanol extract in diet significantly reduced the cortisol level before as well as after acid stress. Similar trend was also found in serum glucose, serum cholesterol, ALT and AST after acid stress. However, serum cholesterol showed no significant effect before acid stress. Acid stress increased the glycolytic, gluconeogenic, protein metabolic and antioxidative enzymes to cope up with acid stress. Our results indicated that methanol extract of C. dactylon at different level possesses good anti stress activity. Hence, supplementation of C. dactylon methanol extract in fish diet at a minimum level of ≥0.5% concomitantly reduced the stress in L. calbasu exposed to acid stress.