RESUMO
Objective: To screen the preliminary phytochemical components, to investigate the acute oral toxicity, the analgesic and anti-inflammatory effects, and to analyze inflammatory factors on mice or rats of 70% ethanol extract of Zygopgyllum macropodum aerial parts (ZME). Methods: Preliminary phytochemical screening was carried out by color reaction. Acute oral toxicity was investigated by body weight, relative organ weight and other toxic signs. Acetic acid induced writhing and hot plate test were used to determine analgesic effect. Acetic acid induced vascular permeability and carrageenan induced paw edema were used to confirm anti-inflammation. Protein in pleural effusion, prostaglandin E2 (PGE2) and tumor necrosis factor alpha (TNF-α) in serum of pleuritic rats induced by carrageenan were analyzed to explore the action mechanisms. The test groups received ZME with 100, 300, 600 mg/kg, the positive control with aspirin (ASP) 200 mg/kg for mice, and ZME with 70, 210, 420 mg/kg and ASP 150 mg/kg for rats orally. The control (C) or negative control (NC) groups received 2% Tween 80 of 10 mL/kg orally. Results: ZME contain flavonoids, saponins, phenols and tannins, steroids, terpenoids, fats and oils, glycosides, carbohydrates, and reducing sugar, but no alkaloids. The lethal dose 50% (LD50) of ZME was greater than 2000 mg/kg and no toxic or deleterious effects and death during 14 d. Oral administration 300 and 600 mg/kg of ZME produced analgesic and anti-inflammatory effects significantly (P < 0.05 or P < 0.001) vs NC. It can reduce the writhing number, prolong the heat resisting time, suppress the permeability of the capillary wall increasing, mitigate the paw edema, reduce the content of protein in pleural effusion, and reduce PGE2 and TNF-α in blood. Conclusions: ZME possessed analgesic and anti-inflammatory activities which related to inhibit the production of protein, PGE2 and TNF-α. The LD50 of ZME treated orally to mice was greater than 2000 mg/kg.