Hepatoprotective activity of flavonoids from Cichorium glandulosum seeds in vitro and in vivo carbon tetrachloride-induced hepatotoxicity

Abstract

Ethnopharmacological relevance: Cichorium glandulosum Boiss. et Huet was used historically in Uyghur folk medicine. Its roots, seeds, and aerial parts are extensively used by Uyghur residents in Xinjiang to eliminate savda typhoid, dredge and cure obstructive jaundice variety liver disorders.

Aim of the study: To evaluate the hepatoprotective activity of total flavonoids (TFs) obtained from C. glandulosum seeds against carbon tetrachloride (CCl4)-induced liver damage in vitro and in vivo. To investigate the mechanisms of hepatoprotective effects for TFs.

Materials and methods: The dried seeds of C. glandulosum were extracted with 70% aqueous ethanol, and the extract was chromatographed with D101 macroporous resin. In vitro the antioxidant capacity against lipid peroxidation (LPO) was evaluated using ferrothiocyanate, thiobarbituric acid, β-carotene bleaching, and LPO inhibition assay. The cytotoxicity and hepatoprotective activity of TFs were evaluated in human liver hepatoma cells (HepG2). MTT assay, hepatic injury markers aspartate aminotransferase (AST), alanine aminotransaminase (ALT), lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA), and glutathione (GSH) were performed. In vivo the hepatoprotective activity of TFs against CCl4-induced acute liver injury was evaluated in rats. A series of biochemical and antioxidant parameter levels were measured in liver homogenate. The suppressive effect on pancreatic lipase activity was determined.

Results: Results indicated that TFs showed antioxidant capacity against lipid peroxidation (LPO). Administrating CCl4 (1%, v/v) caused a significant decrease in HepG2 viability. Treatment with TFs at doses (62.5, 125, and 250 μg/ml) could significantly ameliorate the cytotoxicity and decline the levels of AST, ALT, and LDH induced by CCl4. The markers including MDA and GSH, which were close to oxidative damage, were restored. Oral treatment with TFs in vivo at doses of 100, 200, and 400 mg/kg significantly reduced the levels of AST, ALT, alkaline phosphatase (ALP), total bilirubin (TB), and thiobarbituric acid reactive substances (TBARs) in the serum compared with CCl4-induced acute liver injury in rats. TFs showed dose-dependent suppressive effects on pancreatic lipase activity, and the IC50 was 1.318 ± 0.164 mg/ml.

Conclusion: TFs from C. glandulosum seeds demonstrated significant hepatoprotection against CCl4-induced hepatotoxicity. TFs exhibited significant suppression of LPO and pancreatic lipase capacity, which may be the mechanisms of hepatoprotective effects against CCl4. Our results contribute towards validation of the traditional use of C. glandulosum seeds in the treatment of liver disorders.

Keywords: Cichorium glandulosum seed; Flavonoids; Hepatoprotective; Lipid peroxidation inhibition; Pancreatic lipase.