Potencial antioxidante extratos obtidos a partir de resíduos de frutos amazônicos

Abstract

Antioxidants are natural or synthetic compounds with the ability to inhibit the action of free radicals providing protection against the development of diseases metabolic origin. In last years, studies on antioxidants area have their focus to clarify the application of these models to human or animal diseases. Amazonian fruits are known for their high content of antioxidant compounds and residues that are discarded in the processing of these fruits can be used as raw materials for the food and cosmetics industries. In this context, the aim of this study was to determine the antioxidant potential of extracts obtained from residues of Amazonian fruits consumed by the population in the Amazon. Acai, Brazil nut and tucumã residues were selected and of these extracts, with various proportions of ethanol:water, were obtained dried extract. Antioxidant activity in vitro as free radical DPPH•-, ABTS•- O2•- scavengers and quantification of totals phenolics and flavonóides, as well as antioxidant testing in MRC -5 cells was performed to characterize the antioxidant capacity of the extract. After that, in vivo tests using mice have been performed by inducing CCl4 – induced liver damage. The biochemical parameters of liver injury in animals and biochemical markers of oxidative stress and antioxidant capacity were evaluated. The results showed that extracts of acaí residues (37,25 ± 1.87 %) and tucumã ( 20.99 ± 0.81 % ) are rich in phenolic compounds. However, Brazil nut showed a content only 4,44 ± 0.22 % of phenolic . It have been observed which acai tucumã and showed a scavenger activity in DPPH•- (9,56 ± 0.46 and 21,77 ± 1.46 mg/mL ) and in ABTS•- (17,88 ± 0.49 and 37,25 ± 0.52 mg/mL ). However, were required greater concentration IC50 50 mg / mL to inhibit anion radical O2•-. The concentrations of 100 µg/mL were cytotoxic to cells. Despite this, the Brazil nut at the same concentration was not toxic, allowing cellular viability. Treatment of liver damage in mice with the extracts was significant (p < 0.05) decreasing oxidative stress induced by CCl4. The profile of antioxidant markers was improved in the treated groups and antioxidant capacity was increased in concerning baseline group. However, it was observed that a dose of 400 mg / mL had a pro-oxidant effect. All extracts showed a hepatoprotective activity reducing the plasma concentration of transaminase. The Brazil nut extract was more effective regarding this activity. The dried extracts derived of these fruits waste showed antioxidant potential in vitro and in vivo as well as hepatoprotective activity. Therefore, this results suggest which these extracts have compounds which can be employed by local industries, cosmetic or can be used as nutraceutical in the food industry.