Identificação dos constituintes químicos e estudo farmacológico do óleo essencial das folhas da Croton argyrophylluskunth ; Identification of chemical constituents and pharmacological study of the essential oil of Croton argyrophylluskunth leaves

Inflammation is an important component of many diseases whose central process is the recruitment of phagocytic cells causing tissue damage. The therapeutic use of natural products is an alternative for treating various diseases, in this sense, the species of the Croton (Euphorbiaceae) genus are widely used in folk medicine. We highlight the Croton argyrophyllusKunth, a shrub abundant in northeastern Brazil, whose infusion of its leaves and flowers is used in the treatment of headache, flu, and as a tranquilizer. This study investigates the chemical constituents and evaluates the anti-inflammatory, antinociceptive, and antioxidant properties of the essential oil (EO) of this plant. Croton argyrophyllusKunthEO was obtained from fresh leaves and administered in rodents per orally (p.o.) at the doses of 10, 30, and 100 mg/kg, and was used as a vehicle 0.2% tween 80 in saline (10 mL/kg, p.o.), administered 1 h before the phlogistic agent. It was observed that Croton argyrophyllusKunthEO inhibited paw edema induced by carrageenan (30 and 100 mg/kg), reduced neutrophil recruitment into the abdominal cavity at all doses studied, and inhibited the production of nitric oxide metabolites (NO) in the peritoneal wash (100 mg/kg). Croton argyrophyllusKunthEO administered orally, produced dose-dependent inhibition in visceral nociception induced by acetic acid. In the hot plate test, the EO (100 mg/kg) produced significant antinociceptive effect. In the formalin test, the EO significantly inhibited the time-licking bite, both in the initial phase (neurogenic; 100 mg/kg) and late phase (inflammatory; 30 and 100 mg/kg) in the model. Pretreatment with the EO (30 and 100 mg/kg) led to a significant reduction in dose-dependent nociception induced by capsaicin and glutamate. We also observed, at the dose of 100 mg/kg, which nociception in the hot plate test was significantly attenuated by intraperitoneal injection of naloxone (5 mg/kg). In contrast, the antinociception caused by the EO (100 mg/kg) in the writhing abdominal test was ...