Efeito antimutagênico, antigenotóxico, antiobesidade e antioxidante da Ilex paraguariensis (erva-mate)

Abstract

Yerba mate extract, made from dried leaves of Ilex paraguariensis, is a tea-like beverage consumed in South America. Here, we aim, firstly, to characterize the compounds present in yerba mate beverages available in the Brazilian market (chimarrao CH; mate tea T; mate tea commercially packed in bottles B and cups ready-to-drink C; and roasted yerba mate soluble tea TS). We also evaluated its mutagenic, cytotoxic and antimutagenic properties through Ames test in the presence and absence of metabolic activation. Then, we analyzed exclusively TS sample (2.5, 5.0 and 10 mg/mL) as its antioxidant activity, on plasmid DNA cleavages and upon epithelial esophagus primary culture of Wistar rats treated with a genotoxic agent. Futhermore, we evaluated the effects of mate tea (TS) upon the hypothalamic changes of leptin and insulin signaling and hepatic oxidative stress in postnatal early overfeeding (S) rats. To induce S, litter size was reduced to three pups per dam and normal litters (ten pups/dam) were used as control. In postnatal day (PN) 150, S offspring were subdivided into: S and TS groups treated, respectively, with water or mate tea (1g/kg BW/day, by gavage) during 30 days. C offspring received water. Our results showed the presence of chlorogenic acid, caffeine and theobromine in all analyzed samples. The contents of phenolic compounds in the studied infusions were CH:5,14±0,23; T:4,33±0,01; B:0,93±0,25; C:0,80±0,3 and TS:8,35±0,5 mg/mL. No mutagenic or cytotoxic effect was observed for all analyzed samples. A significant antimutagenic effect was observed for S.typhimurium TA97 (CoT, PreT and PosT), in the presence of metabolic activation, for all tested samples. TS sample also exhibited a significant antimutagenic effect for S.typhimurium TA102 (CoT, PreT and PosT) in the presence of metabolic activation. We did not observed an antimutagenic effect using TA98, TA100 and TA102 for CH, T, C and B samples; and no effect for TA98 and TA100 for TS sample. The exclusive analysis of TS sample, demonstrated an IC50 value of 69,3+3,1μg/ml, in DPPH radical scavenging assay. We also observed a protective effect of TS on plasmid DNA against cleavages induced by superoxide and hydroxyl radicals, in a dose dependent manner. In the comet assay, we detected an antigenotoxic effect of TS in esophagus primary cultures. Our in vivo tests showed that postnatal S rats treated with TS presented lower body weight, total body fat, total visceral fat and food intake. The hypothalamic resistance to leptin was not significantly reversed, although insulin resistance was minimized by TS in the group programmed by neonatal overfeeding. In liver, mate treatment normalized the activities of the antioxidant enzyme activities (SOD, GPx and CAT) and decreased the oxidative stress markers, MDA and 4-HNE. The treatment with TS also reduced the liver glycogen and triglycerides contents. Taken together, our results suggest that yerba mate have a potential to protect DNA against oxidative damage, increased antioxidant defences, improved liver function in adult S rats, maybe through modulation of hypothalamic insulin signaling and may be an important tool to prevent and manage oxidative stress related disorders.