Marcelo Eustáquio Silva's research while affiliated with Universidade Federal de Ouro Preto and other places

This study aimed to evaluate the chemical and biological quality of Gryllus assimilis flour, through the analysis of nutritional and biochemical parameters of tests on young rats (Rattus norvegicus – Fischer). The most deficient essential amino acid was methionine, with a chemical score of 56.40%. For the net protein ratio (NPR) and net protein utilisation (NPU) ratio, the diet containing unsupplemented cricket flour was not enough to reach the NPR and NPU levels of the control group and was insufficient to promote weight gain in the rats. The addition of methionine and wheat bran increased the digestibility of the cricket flour, which resulted in a significant improvement in the levels of cricket protein utilisation, increasing the rates mentioned above and promoting weight gain in the rats. Based on our results, we can state that considering the age of the study animals, cricket meal was a sufficient source of protein for maintenance of body weight, but not for weight gain. Based on biochemical parameters (total protein, albumin, alanine transaminase, aspartate transaminase, creatinine, urea), the cricket meal did not compromise the general health of the study animals. We therefore conclude that the addition of other sources of methionine to cricket flour can be a fundamental strategy for better use of cricket proteins in the diet.

Purpose: The ability of foods to aid in the prevention of chronic metabolic diseases, has recently become an area of increased interest. In addition, there is growing interest in exploring the benefits of consuming underutilized fruits as alternatives to commercially available fruits. Eugenia uvalha Cambess (uvaia) is a native fruit of Brazil with great market and phytotherapy potential. The present study was conducted to investigate the effects of uvaia juice (UJ) on the levels of protein carbonyls (PCO) and antioxidant enzymes in the livers of rats fed a high-fat diet. Methods: Thirty-two female rats were randomly assigned to four groups. The rats were fed either a standard diet (group C) or a high-fat diet (group HF). In addition, groups CUJ and HFUJ were treated with UJ (2mL/day) administered via gavage for 8weeks. Results: In our study, UJ displayed high antioxidant activity (135.14±9.74 GAE/100g). Administration of UJ caused a significantly reduced concentration of rat liver PCO (47.4%), which was associated with a 29% increase in catalase activity. A significant increase in the concentration of oxidized glutathione (GSSG) (15.04±5.08nmol/ml) and a reduction in the reduced glutathione/oxidized glutathione ratio (GSH/GSSG) (11.30±2.68) were found in the HF group, whilst these changes were not observed in the HFUJ group (a result similar to that of group C). Conclusions: Our results demonstrate that UJ decreases oxidative damage by improving antioxidant efficiency and attenuating oxidative damage to proteins.

Buriti pulp flour (BPF) contains significant levels of antioxidants. This study evaluated the effect of BPF on biomarkers of oxidative damage in the liver, heart, and pancreas of diabetic rats. The chemical composition, antioxidant capacity, and polyphenol content of BPF were determined. Thirty-six female Fisher rats were divided into four groups: control (C); control + BPF (CB); diabetic (D); diabetic + BPF (DB). Diabetes was induced by treatment with streptozotocin. Thirty days after the induction of diabetes, glucose, total cholesterol and triacylglycerides serum levels, aminotransferase and paraoxonase activities were evaluated. Oxidative damage to lipids and proteins was assessed through thiobarbituric acid reactive substances (TBARS) and protein carbonyl analyses, respectively. Histopathological analyses were also performed. BPF contained high concentrations of phenolic compounds, lipids, and fibers, and exhibited a high capacity to neutralize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Diabetes was evidenced by equivalent high levels of glucose in plasma from rats in the D and DB groups. Diabetic rats in both groups also presented the same increased activity of aminotransferases. Protein carbonyl levels were increased in liver, heart, and pancreas in the D compared with C group. Although treatment with BPF did not result in any histopathological alterations, it reduced significantly the levels of TBARS in the heart and protein carbonyls in the liver and heart. No effect on blood glucose and tissue histology was observed following treatment with BPF. However, BPF diminished oxidative damage in liver and heart, indicating a possible antioxidant potential in vivo, in addition to in vitro.