Studies on the antioxidant and hepatoprotective activities of polysaccharides from Talinum triangulare

Abstract

ETHNOPHAMACOLOGICAL RELEVANCY: The whole plant of Talinum triangulare (Family: Portulacaceae) is used in variety of diseases including hepatic ailments in Africa and Taiwan of China. The study was aimed to evaluate the antioxidant and hepatoprotective activity of polysaccharides from T. triangulare (TTP). The TTP was extracted using boiling water, and removed protein by Sevag method. 40%, 60% and 80% ethanol precipitating TTP (40%, 60%, 80% TTP) were gained by the successive addition of absolute ethanol. The antioxidant activities of 40%, 60%, 80% and crude TTP were evaluated using three different models in vitro, including reducing power, hydroxyl radicals, superoxide anion. To investigate the hepatoprotective potential, mice were treated with crude polysaccharides (50, 100 and 200mg/kg, p.o.) for 7 days. Liver injures were induced by CCl(4) (0.1% in arachis oil, 10mg/kg, i.v.) 1h after the drug administration on day 7. Mice were sacrificed at 24h after the CCl(4) injection. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) in serum, and glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA) in liver tissues were measured. Histopathological examinations were carried out to supplement the biochemical results. In vitro assays, TTP showed remarkably different degrees of antioxidant activities in dose-dependent manners. The crude TTP demonstrated a relatively strong antioxidant activity, while the 40% TTP showed the strongest antioxidant activity, and the 60% TTP had the weakest antioxidant ability. In vivo assay, pretreatment with TTP had significantly decreased the levels of AST, ALT and MDA against CCl(4) injures, and restored the activities of defense antioxidant substances SOD and GSH towards normalization. These results supported the effect of T. triangulare in fork use with scientific evidence.