Linum corymbulosum Protects Rats against CCl4-Induced Hepatic Injuries through Modulation of an Unfolded Protein Response Pathway and Pro-Inflammatory Intermediates

Liver fibrosis is a major pathological feature of chronic liver disease and effective therapies are limited at present. The present study focuses on the hepatoprotective potential of L. corymbulosum against carbon tetrachloride (CCl4)-induced liver damage in rats. Analysis of Linum corymbulosum methanol extract (LCM) using high-performance liquid chromatography (HPLC) revealed the presence of rutin, apigenin, catechin, caffeic acid and myricetin. CCl4 administration lowered (p < 0.01) the activities of antioxidant enzymes and reduced glutathione (GSH) content as well as soluble proteins, whereas the concentration of H2O2, nitrite and thiobarbituric acid reactive substances was higher in hepatic samples. In serum, the level of hepatic markers and total bilirubin was elevated followed by CCl4 administration. The expression of glucose-regulated protein (GRP78), x-box binding protein-1 total (XBP-1 t), x-box binding protein-1 spliced (XBP-1 s), x-box binding protein-1 unspliced (XBP-1 u) and glutamate-cysteine ligase catalytic subunit (GCLC) was enhanced in CCl4-administered rats. Similarly, the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemo attractant protein-1 (MCP-1) was strongly increased with CCl4 administration to rats. Co-administration of LCM along with CCl4 to rats lowered (p < 0.05) the expression of the above genes. Histopathology of the liver showed hepatocyte injury, leukocyte infiltration and damaged central lobules in CCl4-treated rats. However, LCM administration to CCl4-intoxicated rats restored the altered parameters towards the levels of control rats. These outcomes indicate the existence of antioxidant and anti-inflammatory constituents in the methanol extract of L. corymbulosum.