Avaliação da toxicidade e da atividade anti inflamatória do óleo essencial das folhas de Piper glabratum em camundongos

Abstract

Although the species of the genus Piper exhibit interesting biological properties, studies on Piper glabratum are very limited. This study aimed identify the chemical compounds of the essential oil from P. glabratum leaves (OEPG) by gas chromatography and investigate its anti-inflammatory potential, as well, determine the safety of this oil after acute and subacute exposure in mice. The acute toxicity of OEPG was evaluated by oral administration to female mice as single doses of 500, 1000, 2000 or 5000 mg/kg/body weight. In the subacute toxicity test, females received 500 or 1000 mg/kg/body weight of OEPG for 28 days. The anti-inflammatory potential of OEPG was evaluated using the four models including pleurisy, edema, mechanical hyperalgesia and cold allodynia models in mouse paw. After gas chromatography analysis the majority compounds were β-pinene (12.97%), longiborneol (12.00%), α-pinene (9.67%), caryophyllene (7.95 %), viridiflorene (7.34%), β-copaeno (6.55%) e β- damascenone (5.85%). No clinical signs of toxicity were observed in animals after acute treatment, suggesting that the LD50 is greater than 5000 mg/kg. The subacute exposure to OEPG produced no significant changes in hematological or biochemical parameters. Similarly, the organs histology and the estrus cycle showed no marked alterations. OEPG exhibited anti-inflammatory activity, inhibiting the leukocyte migration (100, 300, 700 mg/kg) and the protein extravasation of pleural exudate (700 mg/kg). After intraplantar injection of carrageenan, it was observed that the 700 mg/kg dose of OEPG decrease edema formation, decreased the mechanical sensitivity and sensitivity to cold. These results suggest the anti-inflammatory potential of essential oil of P. glabratum leaves, without cause toxicity in female mice.