Avaliação in vivo do extrato de alecrim (Rosmarinus officinalis) como antioxidante em camarões (Macrobrachium rosenbergii) e efeitos sobre a composição centesimal da carne

Abstract

Several researches have been developed and directed to the use of natural additives from plant extracts in feeding aquatic animals. Rosemary presents antibacterial, antitumor, anti-inflammatory, analgesic, antioxidant, endocrine and metabolic modulator activity. The objective of the present work was to evaluate in vivo the effects of supplementation with rosemary extract on the physiology and body composition of shrimp (Macrobrachium rosenbergii). The supplementation was carried out in the diet with the following groups: T0, T1, T2 and T3, in the concentrations of 0%, 2%, 5% and 15% of rosemary extract, respectively, during a 90-day period. The following parameters were evaluated: Aspartate aminotransferase (AST) and Alanine Aminotransferase (ALT) activities, antioxidant system and oxidative damage (reduced glutathione content, activity of glutathione reductase and glutathione S-transferase, and levels of lipid peroxidation and carbonylated protein), zootechnical parameters (survival rate, weight gain, length gain). The water quality of the systems was monitored during the whole experimental period. Also, the centesimal composition of the feed and the shrimp meat was evaluated with the following parameters: moisture, ashes, protein content and lipids. The supplementation of rosemary extract did not influence the zootechnical parameters nor the survival of the animals. On the metabolic parameters, the AST activity presented a significant difference (p <0.05) in T1 treatment (2% of rosemary extract) compared to the T0 control. ALT activity showed significant increases in all groups with rosemary extract. There was a reduction in reduced glutathione levels with a significant difference for the highest concentration of extract (15%). Also, significant increases in the activity of glutathione reductase to T2 (5%) and T3 (15%) groups were verified and also a significant increase in glutathione S-transferase activity in all tested concentrations of rosemary extract compared with the control group. Supplementation significantly increased lipid peroxidation levels in T3 treatment whereas no changes in carbonylated protein levels were observed in any of the groups studied. In relation to the centesimal composition of the meat, supplementation promoted changes in lipid content, with a significant reduction in all experimental groups when compared to the control group. The results found after the addition of rosemary extract in the diet and in vivo treatment indicate a pro-oxidant potential of the rosemary extract considering the changes of the antioxidant defense system and body composition observed. From the above it is necessary to carry out further studies with different doses / periods of supplementation in shrimp to determine the actual antioxidant and / or pro-oxidant potential of rosemary.