Biological Activities of Some Algal Extracts from Lebanon; Antioxidant, Anti-inflammatory, and Anti-steatotic Effects

Nonalcoholic fatty liver disease (NAFLD) is a metabolic manifestation of liver disease, characterized by lipid accumulation in hepatocytes. Despite starting as a benign disorder, NAFLD can progress to more severe pathologies such as nonalcoholic steatohepatitis, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. The epidemiological prevalence of this disease is 25 % of the general population, and its worsening suggests that NAFLD is supposed to be the main cause for liver transplantation. NAFLD pharmacological treatment is still limited by unwanted side effects, whereas the best therapeutical approach is a lifestyle that depends on physical exercises and a healthy diet. The use of natural-derived compounds with therapeutic potential is advisable. Recently, medicinal plants applications have been focused on renewable sources as marine algae, especially seaweeds. Seaweeds are characterized with huge amounts of phytochemicals such as fucoidan (FUC) polysaccharide, which is known for its antioxidant, anti-inflammatory, anti-cancer, and hepatoprotective effects. In the present work, we extracted a water soluble fucoidan fraction from the brown algae Cystoseira compressa, and for the first time from the roots of the terrestrial shrub Ferula hermonis. These fucoidan fraction were termed CYS and FER, respectively. Then together with a previously purified fucoidan from the terrestrial plant Eucalyptus globulus “EUC” were studied and compared for their chemical features and biological activities. CYS, FER, and EUC contained fucose, glucose, sulfate, smaller amounts of monosaccharides such as galactose and mannose, and a minor quantity of proteins. FUCs structural features were investigated by FTIR, 1H NMR and 13C NMR spectroscopy. The antioxidant properties of FUCs were measured by DPPH, ABTS and FRAP assays, results revealed a high radical scavenging capacity that was confirmed in in vitro cellular models. In hepatic and endothelial cells, FUC reduced ROS production induced by intracellular lipid accumulation. Moreover, in our NAFLD model that consists of hepatic and endothelial cells treated with a fatty acid mixture prior to the FUCs treatment, FUCs purified from the three vegetal species exhibited a significant antisteatotic action; being able to reduce intracellular triglyceride content and to regulate the expression of key genes of hepatic lipid metabolism. Altogether, our results candidate CYS, FER, and EUC as possible bioactive compounds against fatty liver disease and related vascular damage. Results indicated that among the purified FUCs, that purified from the terrestrial plant E. globulus was the most biologically active extract.