Composição química e potencial antioxidante do cerume de Nannotrigona testaceicornis (HYMENOPTERA, APIDAE, MELIPONINI)

Abstract

Oxidative stress is a condition associated with the development and progression of several diseases, characterized by an imbalance between the production of reactive oxygen species and the body's antioxidant defense. Thus, the discovery of new antioxidant agents is extremely relevant to contribute to the redox state of the body, acting in the maintenance of health, prevention and/or treatment of diseases. Different chemical compounds from bee products have been described for their antioxidant potential. In this context, the present study evaluated the chemical composition, toxicity and in vitro and in vivo antioxidant activity of cerumen from the stingless bee Nannotrigona testaceicornis. The ethanolic extract of cerúmen Nannotrigona testaceicornis (EEC-Nt) was prepared in the proportion of 4.5 ml of 80% ethanol for each 1 g of cerumen, and the content of total phenolic compounds and flavonoids was evaluated. The in vitro antioxidant activity of EEC-Nt was investigated by the scavenging methods of the free radicals 2,2-diphenyl-1- picrylhydrazine (DPPH•) and 2,2´-azinobis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+). The nematode Caenorhabditis elegans was used to evaluate the toxicity and in vivo antioxidant potential of EEC-Nt. The content of phenolic compounds and flavonoids in EEC-Nt was 8.39 ± 0.26 mg EAG/g and 1.59 ± 0.14 mg EQ/g, respectively. The concentrations of EEC-Nt capable of inhibiting 50% of DPPH• and ABTS•+ free radicals were 637.05 ± 3.35 µg/ml and 128.5 ± 3.88 µg/ml, respectively in vivo. EEC-Nt was not toxic to nematodes at the concentrations and times evaluated. However, EEC Nt was not able to promote protection against juglone-induced oxidative stress in C. elegans, but potentiated the toxic effect of this pro-oxidant agent. In summary, this study opens perspectives for investigation of the cytotoxic and adjuvant potential of chemotherapeutics, as well as contributes to bioprospecting and valorization of the apicultural biodiversity of the State of Mato Grosso do Sul.