Inactivation of Kupffer Cells by Selenizing Astragalus Polysaccharides Prevents CCl4-Induced Hepatocellular Necrosis in the Male Wistar Rat.

Selenizing astragalus polysaccharides-3 (sAPS3) was prepared by nitric acid-sodium selenite method. The effects of sAPS3 on carbon tetrachloride (CCl4) induced hepatocellular necrosis, and its underlying mechanisms were studied in male Wistar rats. Hepatic damage was induced by intraperitoneal injection of CCl4 twice a week, for 3 weeks. Meanwhile, the rats in addition to CCl4 were also exposed to sodium selenite (SS), astragalus polysaccharides (APS), SS + APS or sAPS3, in parallel by oral gavage once a day for 3 weeks. At the end of 3 weeks, blood and liver tissue were taken. Serum was collected to test the levels of alanine aminotransferase, aspartate aminotransferase and antioxidant status parameters. Liver tissue was collected for histopathological examination and determination of messenger RNA (mRNA) expression levels of CD68, TNF-α, IL-1β and ATG7 followed by the measurements of CD68, IL-1β and LC3II by immunohistochemistry assay (IHC), or TNF-α by immunofluorescence assay (IFA). The results showed that sAPS3 effectively ameliorated CCl4 induced hepatocellular necrosis and inflammation and significantly decreased the levels of aspartate aminotransferase, alanine aminotransferase, malondialdehyde and the expression levels of Kupffer cells (KCs)-specific biomarker CD68 and proinflammatory cytokines produced by activated KCs such as IL-1β and TNF-α (P < 0.01). While increasing the levels of total antioxidant capacity, glutathione, glutathione peroxidase and superoxide dismutase (P < 0.05) and reduced the expression levels of a key regulator of autophagy in KCs ATG7 or LC3II (P < 0.05). These findings indicate that sAPS3 could ameliorate CCl4-induced hepatocellular necrosis by inactivation of Kupffer cells and its activity may be superior to the application of selenium, APS or combination of selenium with APS.