A NMR-based metabonomic study on the ameliorating effects of Ginkgo biloba extract in rainbow trout, Oncorhynchus mykiss exposed to organophosphate pesticide, diazinon

Abstract

This study was conducted to investigate the ameliorating effects of Ginkgo biloba extract (GE) on diazinon-induced toxicity in rainbow trout from a metabolic point of view using 1H NMR spectroscopy. Fish were divided into two groups including non-diazinon (Non-DZ) and diazinon-exposed (DZ) groups and then supplemented with various dietary levels of GE for 60 days. PLS-DA analysis of blood and liver metabolome confirmed the effects of GE supplementation and exposure to diazinon on separation of the experimental groups. According to loading plot outputs, amino acids, osmolytes and metabolites associated with energy metabolism had more contribution in the separation of the groups. In Non-DZ fish, the levels of almost all amino acids in blood were significantly lower in GE4 treatment (4 g GE/Kg diet) compared to other groups after 60 days feeding trial (P < .01). The levels of glycerol were found to be significantly higher in GE-supplemented fish compared to other groups (P < .01). In DZ groups, the levels of osmolytes including trimethylamine-N-oxide (TMAO), trimethylamine, N,N-Dimethylglycine and betaine decreased in almost all groups compared to corresponding Non-DZ fish (P < .01). Also, the levels of almost all amino acids elevated in control (non-GE-supplemented fish) and treatments GE1 (0.5 g GE/Kg diet) and GE4 (P < .01). The glucose levels also showed significant decreases in control and fish of treatments GE1 and GE4 (P < .01). The levels of lactate significantly decreased in control and treatments GE1, GE2 and GE4 (P < .01). The levels of glycerol and ketone bodies significantly increased in control and groups GE1, GE2 and GE4 (P < .01). Furthermore, the levels of phosphocreatine significantly increased in control and treatments GE1, GE2 and GE4 (P < .01). In Non-DZ fish, the levels of glycerol in liver were significantly higher in GE-supplemented fish compared to other groups (P < .01). In DZ fish, the levels of hepatic succinate increased in control and groups GE1 and GE4 compared to corresponding Non-DZ fish (P < .01). The values of TMAO and trimethylamine decreased in control group (P < .01). However, the levels of N,N-Dimethylglycine decreased in control and fish of treatments GE1, GE2 and GE4 (P < .01). The levels of ketone bodies also showed significant increases in control and treatments GE1 and GE4 (P < .01). The results of the present study showed that ginkgo at optimized dietary levels (1–2 g GE/Kg diet) is capable to ameliorate the toxicity induced by diazinon, mainly through modulating the biochemical pathways related to the metabolism of the amino acids, energetic metabolites and osmolytes.