Regulação fisiológica da butirilcolinesterase através do uso de aditivos alimentares e sua aplicação em rações para camarão marinho

Abstract

Litopenaeus vannamei is the most cultivated crustacean species in the world, representing 51.7% of total production. In Brazil, the species leads the national shrimp farming earning about R$1.6 million. Seeking to optimize cultures, new methods of physiological regulation can generate important results. The investigation of the modulation of the action of enzymes in the endocrine/digestive systems is an alternative with the potential to obtain significant results. Recently, it was proposed that the enzyme butyrylcholinesterase (BChE) plays a role in the metabolism of ghrelin, known as the “hunger hormone” and may influence feed intake and productive performance. The present study aimed to investigate the in vitro effect of BChE inhibitors as a physiological tool using food additives and their application in marine shrimp diets. Juveniles of L. vannamei in the fattening phase (2g, 4g and 6g) were obtained from a local producer and enzyme activity tests were carried out in different tissues (eye, muscle and hepatopancreas) using the IC50 parameter (concentration that inhibits the enzymatic activity by 50%). Tests were carried out to evaluate the inhibitory effect of the following plants: arugula (Eruca sativa), Swiss chard (Beta vulgaris) and spinach (Spinacea oleracea). The best inhibition results were arugula IC50: 0.019μg/mL in 6g shrimp; chard IC50: 0.14μg/mL in 4g shrimp and spinach IC50: 0.20μg/mL in 4g shrimp, chard showed better results for use as an additive. The feed was processed, and inhibitor extracts were added to the feed, in different samples, using grain alcohol as an incorporating vehicle. The physical and bromatological evaluations were then conducted, in the physical tests the repelletized rations showed a difference only in apparent density, even the repelletized rations being denser the buoyancy was not affected, for the bromatological tests they only showed lower humidity, due to the time in the oven. It can be concluded that individuals of average weight (4 g) have greater BChE activity, suggesting that this phase is ideal for introducing feeds with BChE inhibitors and that the inclusion of additives in shrimp feed, using the repellent method, can be used without impairing the nutritional and physical quality of the feed.