<i>Schisandra</i> Lignan Extract Protects against Carbon Tetrachloride‐Induced Liver Injury in Mice by Inhibiting Oxidative Stress and Regulating the NF‐<i>κ</i>B and JNK Signaling Pathways

Abstract

<i>Schisandra chinensis</i> (<i>S. chinensis</i>) is a traditional Chinese herbal medicine widely used for the treatment of liver disease, whose main active components are lignans. However, the action mechanisms of the lignans in <i>S. chinensis</i> remain unclear. This study aimed to investigate the protective effect and related molecular mechanism of <i>Schisandra</i> lignan extract (SLE) against carbon tetrachloride- (CCl₄-) induced acute liver injury in mice. Different doses of SLE at 50, 100, and 200 mg/kg were administered daily by gavage for 5 days before CCl₄ treatment. The results showed that SLE significantly decreased the activities of serum ALT/AST and reduced liver pathologic changes induced by CCl₄. Pretreatment with SLE not only decreased the content of MDA but increased SOD, GSH, and GSH-Px activities in the liver, suggesting that SLE attenuated CCl₄-induced oxidative stress. The expression levels of inflammatory cytokines TNF-a, IL-1<i>β</i>, and IL-6 were decreased after oral administration of SLE, probably because lignans inhibited the NF-<i>κ</i>B activity. Additionally, SLE also inhibited hepatocyte apoptosis by suppressing JNK activation and regulating Bcl-2/Bax signaling pathways. In conclusion, these results suggested that SLE prevented CCl₄-induced liver injury through a combination of antioxidative stress, anti-inflammation, and antihepatocyte apoptosis and alleviated inflammation and apoptosis by regulating the NF-<i>κ</i>B, JNK, and Bcl-2/Bax signaling pathways.