Avaliação da toxicidade e das atividades antimicrobiana e anti-inflamatória do óleo essencial das folhas de Piper vicosanum

Abstract

Piper vicosanum (Piperaceae) is a species traditionally used in folk medicine for the treatment of various diseases such as pain, fever and inflammation. However, there is little scientific evidence of these effects. Thus, this study aimed to evaluate the anti-inflammatory and antimicrobial effects of the essential oil from P. vicosanum leaves (OPV) and determined the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated by oral administration to female rats as single doses of 2000 mg/kg/body weight. General behavior and toxic symptoms were observed for 14 days. To evaluate the genotoxic and mutagenic potential, female mice were divided into five groups: group I: negative control; group II: positive control; group III: 500 mg/kg of OPV; group IV: 1000 mg/kg of OPV; group V: 2000 mg/kg of OPV. Peripheral blood was collected for the comet assay and the micronucleus test. The anti inflammatory activity of essential oil was evaluated in carrageenan-induced pleurisy and paw edema in rats. The antimicrobial activity of OPV was analyzed by the Minimum Inhibitory Concentration test (MIC) against strains of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella sp, Escherichia coli and Candida albicans. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. The comet assay data demonstrated that OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or mutagenic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analysed in carrageenan induced oedema and pleurisy. Moreover, OPV presented antimicrobial activity against all tested microorganisms, with MIC ranging from 250 to100 µg/mL. The present study shows that essential oil of P. Vicosanum leaves has anti-inflammatory and antimicrobial potential without causing acute toxicity or genotoxicity.