Hepatoprotective effect of the fucoidan from the brown seaweed Turbinaria tricostata

Reactive oxygen species (ROS) are involved in initiating and promoting several hepatic diseases. This study was designed to evaluate the in vitro hepatoprotective effect and antioxidative activity of the fucoidan extract from Turbinaria tricostata (FTt) from the coast of the Yucatan Peninsula (Mexico). We compared two different mild condition extraction techniques: water vs. salt extraction. The chemical composition and structure of the FTt extracts were determined by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The antioxidant potential was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay. The cytotoxicity was determined in human hepatoma cell (HepG2) and human embryonic kidney cells (Hek-293). The hepatoprotective effect of fucoidan extracts was evaluated by using the hydrogen peroxide (H2O2)-induced toxicity on HepG2 cells. In order to assess the possible mechanisms of hepatoprotection of the FTt extracts, ROS intracellular inhibition, glutathione (GSH) level, and catalase (CAT) activity were determined. Our results showed that treatment with FTt extracts displayed significant free radical scavenging action against DPPH and induced a hepatoprotective effect by inhibition of ROS generation. This has been attributed to an increase of catalase activity.