Isolamento e identificacao da arctigenina a partir dos frutos da Arctium lappa L. e avaliacao de atividade citotoxica in vitro e hepatoprotetora em ratos

Abstract

Arctigenin is a lignan isolated from Arctium lappa L., this plant, belonging to family Asteraceae is widely used in traditional chinese medicine. Publications suggest numerous pharmacological activities of crude extracts of this plant and arctigenin as anti-inflammatory activity, hepatoprotective, hypoglycemic, anticancer and antimicrobial, however detailed studies of hepatoprotective activity have not yet been widely developed. The aim of this study was the isolation and identification of arctigenin obtained from the fruits of Arctium lappa L., to evaluate the cytotoxic in vitro of arctigenin in cell culture of liver carcinoma (HepG-2) and assess the effects of this isolated compound on liver injury by ligation bile duct (BDL). The crude chloroform extract of Arctium lappa L. was obtained by soxhlet. To isolate the compounds was held vacuum column and observed high concentration of arctiin, a precursor of arctigenin. To obtain arctigenin, it was necessary to carry out a hydrolysis to remove the glucose molecule present in arctiin. After, the molecule was identified by 1H NMR and 13C, attaining excellent purity, and additionally, was carried out his chromatographic profile by HPLC.. In vitro experiments show that the arctigenin decreased cell viability by MTT assay and the Trypan blue on HepG-2 cells and did not cause cytotoxicity on NIH/3T3 cells. Adhesion testing by providing collagen type I on HepG-2 was also carried out to observe the mechanisms involving the antitumor activity of arctigenin. In vivo experiments were performed by surgery in BDL rats, with n = 6 and divided into groups: sham control, sham arctigenin, control BDL, arctigenin BDL and silymarin BDL. The treatment of animals was made for 48 hours and after this period, euthanized and blood and liver were collected for serum biochemical assessments (AST, ALT, FA and TNF-α) and also tissue rating (MPO). The methodology of extraction, isolation and obtaining arctigenin developed was effective, decreased spending solvents and the time to get compounds. The trust parameters analyzed by HPLC showed that the analytical method was specific and reproducible, which contributes to quality control studies and bioanalytical assays. The arctigenin demonstrated cytotoxic activity and anti-adhesion, and dependent dose activity in HepG-2 cells, with IC 50 of 90.8 μM. No activity on NIH/3T3 cells, demonstrating the specific action on HepG-2 cells. Results of BDL done in 48 hours showed no significant results when comparing with control groups and positive control, however, literature reports show that the arctigenin is a promising compound and hepatoprotection studies for longer periods would complement the elucidation of its activity.