Seabuckthorn berry polysaccharide protects against carbon tetrachloride-induced hepatotoxicity in mice via anti-oxidative and anti-inflammatory activities

The berries of Seabuckthorn (Hippophae rhamnoides L.) are traditional medicinal foods that have been used by Tibetans and Mongolians for thousands of years. The polysaccharides are the main components of Seabuckthorn berries, possessing immune stimulating, anti-cancer and anti-fatigue activities. The present study focused on evaluating the protective effects and mechanisms of Seabuckthorn berry polysaccharide (SP) against carbon tetrachloride (CCl4)-induced hepatotoxicity. Mice were orally administrated with 50, 100 and 200 mg kg-1 of SP once daily for 14 consecutive days prior to CCl4 challenge. Pretreatment with SP significantly decreased alanine transaminase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) levels, while increasing the levels of prealbumin (PALB) in the CCl4-challenged mice, which were accompanied by diminished liver injuries, increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, increased GSH levels, and reduced malondialdehyde (MDA) content. The pretreatment with SP also markedly reduced the CCl4-induced expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), inducible nitric oxide synthase (iNOS) and nitric oxide (NO). Furthermore, the pretreatment with SP decreased hepatic Toll-like receptor 4 (TLR4) expression and inhibited the phosphorylation of p38 MAPK, extracellular signal-regulated kinase (p-ERK), c-Jun N-terminal kinase (p-JNK) and nuclear factor-kappa B (NF-κB) in the CCl4-challenged mice. These results suggest that the pretreatment with SP protected against CCl4-induced liver damage via its anti-oxidative and anti-inflammatory activities. SP might be suitable for functional foods and natural drugs in preventing CCl4-induced hepatotoxicity.