Hypoglycemic effect of the methanol flower extract of piper claussenianum and the major constituent 2',6'-dihydroxy-4'-methoxychalcone in streptozotocin diabetic rats
1Nucleo de Pesquisas de Produtos Naturais, Centro de Ciencias da Saude, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil 2Programa de Desenvolvimento de Farmacos, Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil 3Escola de Medicina, Fundacao Tecnico Educacional Souza Marques, Rio de Janeiro, RJ, Brazil 4Departamento de Produtos Naturais, Far-Manguinhos, Fiocruz, Rio de Janeiro, RJ, Brazil 5Instituto de Pesquisa Jardim Botanico do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
G Z Sudo Programa de Desenvolvimento de Farmacos, Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ Brazil E-mail: [email protected]
Piper claussenianum inflorescences crude methanol extract was tested for hypoglycemic effect in streptozotocin-induced diabetic rats. The blood glucose levels of rats treated with methanol extract were reduced from 318.4±28.1 mg/dl before treatment to 174.2±38.3 mg/dl after 12 days of treatment (P<0.05). Phytochemical studies were carried out on inflorescences methanol crude extract in order to investigate the possible metabolites responsible for the pharmacological properties of the extract. After chromatographic procedures, three flavonoids were isolated and characterized. The major compound 2',6'-dihydroxy-4'-methoxychalcone was also tested. Rats that received the chalcone content also displayed a reduction in blood glucose levels from 277.4±7.7 mg/dl before treatment to 158.8±9.2 mg/dl after 12 days of treatment (P<0.05). The results suggest this chalcone is one of the metabolite responsible for the blood glucose levels reduction in rats with streptozotocin-induced diabetes. The inflorescence crude extract of P. claussenianum was found to be composed mainly by flavonoids and may be a potential natural source of compounds with hypoglycemic properties.