Hot water extracted Lycium barbarum and Rehmannia glutinosa inhibit liver inflammation and fibrosis in rats

Polysaccharide-rich Lycium barbarum and Rehmannia glutinosa have been considered to have immune-modulating activity. This study investigated the effects of water extracted Lycium barbarum and Rehmannia glutinosa (HE) on carbon tetrachloride (CCl ₄)-induced liver injury in rats. Male Sprague-Dawley rats were randomly divided into: normal diet + peritoneal injection of olive oil (control), normal diet + CCl ₄ injection (CCl ₄), 1 × HE (0.05% HE for each) + CCl ₄ (1 × HE), and 3 × HE (0.15% HE for each) + CCl ₄ (3 × HE) groups. Rats were injected with 40% CCl ₄ at a dose of 0.75 ml/kg body weight once a week for seven weeks, one week after herbal extract treatment. After eight week herbal extract treatment, pathohistological examination showed that both 1× and 3 × HE treatments diminished necrotic hepatocytes, chemoattraction of inflammatory cells, and liver fibrosis. Both 1× and 3 × HE treatments decreased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and reduced hepatic levels of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1β compared to CCl ₄ treatment alone. The 1 × HE treatment increased hepatic anti-inflammatory cytokine IL-10 levels. Both the 1× and 3 × HE treatments suppressed liver fibrosis biomarkers transforming growth factor-β1 and hydroxyproline. Therefore, treatment with water extracted Lycium barbarum and Rehmannia glutinosa (0.05% and 0.15% for each) for eight weeks protects against necrotic damage, indicated by decreases in plasma ALT and AST activities, and suppresses liver fibrosis by down-regulation of liver inflammation in rats with CCl4-induced liver injury.