To explore the mechanism of Rhei Radix et Rhizoma combined with Scutellariae Radix in regulatory lipopolysaccharide (LPS)-induced liver inflammation in rats with endotoxin blood, 50 male SD rats were selected and randomly divided into blank group, model group, dexamethasone group, herbal pair high dose group, herbal pair low dose group, with 10 in each group. Rats in each were given preventive drugs for 7 consecutive days. At 0.5 h after the final administration, the model was built through the tail vein injection with LPS (5 mg•kg⁻¹). Then, animal anal temperatures were determined and recorded once every 0.5 h. The rats were killed at 4 h after the modeling to determine spleen thymus coefficient. ELISA method was used to detect cytokines interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) in liver tissues. The colorimetric method was applied in determination of oxidation nitrogen (NO) content in liver tissues. Western Blot method was adopted to detect Toll-like receptor protein 4, p38MAPK p38MAPK, phosphorylated p38MAPK (p-p38MAPK) and nitric oxide synthase (iNOS) protein expressions. The results showed that compared with the blank group, in the model group, TLR4 protein expression, iNOS protein expression and p38 phosphorylation expression, IL-1β, NO and TNF-α content increased significantly in liver tissues (P<0.05 or P<0.01). And compared with the model group, the herbal pair high dose group showed significantly reduction in IL-1β, NO and TNF-α expressions in rat liver tissues (P<0.05 or P<0.01), down-regulation in iNOS protein expression and p38 phosphorylation expression in rat liver tissues (P<0.05), but without significant up-regulation in TLR4 protein. Low-dose herbal pair can significantly reduce IL-1β and NO expression in model rat liver tissues (P<0.01), significantly down-regulate iNOS protein expression (P<0.01), with a slight down-regulation in phosphorylation of p38 but no statistical significance, and no reduction in TLR4 expression. In conclusion, the compatibility of Rhei Radix et Rhizoma combined with Scutellariae Radix may reduce the expression of iNOS protein and the release of inflammatory cytokines IL-1β, NO and TNF-α by decreasing p38 protein phosphorylation expression and blocking p38MAPK signaling pathways, so as to alleviate the inflammation reaction and protect the liver.
Keywords: Rhei Radix et Rhizoma; Scutellariae Radix; TLR4; endotoxemia; p38MAPK.
Copyright© by the Chinese Pharmaceutical Association.