Antioxidant Activity of Aqueous Extract of Leaves and Seeds of Datura metel (Solanaceae) in Frog's Heart Failure Model

OBJECTIVE: The aim of this work was to evaluate the antioxidant potential of Datura metel. MATERIALS AND METHODS: Heart failure was induced in the frog's heart by continuous perfusion of hydrogen peroxide. Survival time and some heart tissue parameters of oxidative stress were recorded in the presence of aqueous extracts of the leaves and seeds of Datura metel. Ascorbic acid was used as a reference drug. RESULTS: H(2)O(2)-enriched Ringer's solution inhibited the negative inotropic and chronotropic effects of acetylcholine, indicating the desensibilization of muscarinic receptors due to H(2)O(2)-induced oxidative stress. These hearts had a relatively short survival time (14 minutes). In the presence of the aqueous extract of the leaves and seeds of Datura metel (1.5 and 2.5 mg/mL), the time necessary to cause the cardiac arrest was extended to 35 and 37 minutes, respectively, versus 29 minutes for ascorbic acid and 14 minutes for H(2)O(2). Furthermore, antioxidant parameters (MDA, SOD, and CAT) were significantly improved in plant extract-treated hearts, compared to peroxidized hearts. CONCLUSION: Aqueous extract of the leaves and seeds of D. metel can extend heart survival time through antioxidant mechanisms.