Oryza sativa L. Indica Seed Coat Ameliorated Concanavalin A—Induced Acute Hepatitis in Mice via MDM2/p53 and PKCα/MAPK1 Signaling Pathways

Acute hepatitis (AH) is a common liver disease with an increasing number of patients each year, requiring the development of new treatments. Hence, our work aimed to evaluate the therapeutic effect of Oryza sativa L. indica (purple rice) seed coat on concanavalin A (ConA)-induced AH and further reveal its potential mechanisms. Purple rice seed coat extract (PRE) was extracted with hydrochloric acid ethanol and analyzed through a widely targeted components method. We evaluated the effects of PRE on AH through histopathological examination, liver function, gut microbiota composition, and the intestinal barrier. The potential targets of PRE on AH were predicted by bioinformatics. Western blotting, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining, and corresponding kits were used to investigate PRE effects on predicting targets and associated signaling pathways in AH mice. In AH model mice, PRE treatment increased transformed mouse 3T3 cell double minute 2 (MDM2) expression to inhibit apoptosis; it also markedly downregulated protein kinase C alpha (PKCα), prostaglandin-endoperoxide synthase 1 (PTGS1), and mitogen-activated protein kinase 1 (MAPK1) activity to alleviate inflammation. Thus, PRE treatment also recovered the intestinal barrier, decreased the lipopolysaccharide (LPS) levels of plasma and the liver, enhanced liver function, and improved the composition of intestinal microbiota. In general, PRE targeting MDM2, PKCα, MAPK1, and PTGS1 ameliorated ConA-induced AH by attenuating inflammation and apoptosis, restoring the intestinal barrier, enhancing the liver function, and improving the gut microbiota, which revealed that the purple rice seed coat might hold possibilities as a therapeutic option for AH.