Antinociceptive effect of the Orbignya speciosa Mart. (Babassu) leaves: Evidence for the involvement of apigenin

• DOI: 10.1016/j.lfs.2012.06.013
• Publication Date: 2012-06-28T00:16:46Z
• Authors: Mariana Martins G...; Fábio Boylan; Patrícia Dias Fer...
• Keywords: Atropine; Male; Analgesics; 0303 health sciences; Aspirin; Dose-Response Relationship, Drug; Morphine; Antinociceptive activity; Biochemistry, Genetics and Molecular Biology(all); Naloxone; Plant Extracts; Orbignya speciosa; Pain; Arecaceae; Mecamylamine; 3. Good health; Plant Leaves; Pharmacology, Toxicology and Pharmaceutics(all); Disease Models, Animal; Mice; 03 medical and health sciences; Animals; Apigenin; Brazil

Babassu is the common Brazilian name of Orbignya speciosa Mart. (Arecaceae). The fruits are used for several disorders. In the present study, the antinociceptive effects of the ethanol extract (EE) and dichloromethane fraction (DF) obtained from leaves were investigated, as well as apigenin using nociception models (acetic acid-induced abdominal writhing, formalin, and hot plate).Mice were treated with EE, DF (10, 30, and 100mg/kg, p.o.), apigenin (1mg/kg, p.o.), morphine (5mg/kg, s.c.), acetylsalicylic acid (100mg/kg, p.o.) or vehicle (0.1 ml, p.o.). The EE and DF reduced the contortions induced by acetic acid. Both also reduced the licking response in the formalin model. In the hot plate model, the antinociceptive effects were, at least, equal to that shown by morphine. To elucidate the antinociceptive mechanism of action of EE, DF, and apigenin the animals were pre-treated with atropine (nonselective muscarinic receptor antagonist, 1mg/kg, s.c.), naloxone (opioid receptor antagonist, 1mg/kg, s.c.), l-nitro arginine methyl ester (L-NAME, nitric oxide synthase inhibitor, 3mg/kg, s.c.) or mecamylamine (nicotinic receptor antagonist, 2mg/kg, s.c.) and evaluated in the hot plate model.The antinociception produced by DF was abolished by atropine, naloxone or mecamylamine. The effect of apigenin was significantly blocked by atropine or naloxone.The results obtained indicated that EE and DF have antinociceptive activity that is mediated, at least in part, by opioid and cholinergic systems. This effect can be attributed to the presence of apigenin, a flavonoid in the dichloromethane fraction.