Kokusaginine attenuates renal fibrosis by inhibiting the PI3K/AKT signaling pathway

Kokusaginine is an active ingredient alkaloid that has been isolated and extracted from Ruta graveolens L. Some researches have indicated that alkaloids possess anti-inflammatory and antioxidant effects. Nevertheless, the potential nephroprotective effects of kokusaginine on renal fibrosis remain undetermined. This study was conducted to examine the protective effect of kokusaginine on renal fibrosis and to explore the underlying mechanisms using both in vivo and in vitro models. Renal fibrosis was induced in male C57BL/6 J mice by feeding with 0.2% adenine-containing food and UUO surgery. Kokusaginine was administered orally simultaneously after the establishment of renal fibrosis. Renal function was measured by serum levels of creatinine and urea nitrogen. Renal pathological changes were assessed by HE staining and Masson staining. Western blotting was employed to detect the expression levels of fibrosis-related proteins in mice and cells. Additionally, network pharmacology analysis and RNA-seq were utilized to predict the pathways through which kokusaginine could exert its anti-fibrotic effects. The treatment with kokusaginine enhanced renal function, alleviated renal histoarchitectural lesions, and mitigated renal fibrosis in the renal fibrosis models. The network pharmacology and RNA-seq enrichment analysis of the KEGG pathway demonstrated that kokusaginine could exert anti-renal fibrosis activity via the PI3K/AKT signaling pathway. And the results were verified in both in vitro and in vivo experiments. In conclusion, our data implied that kokusaginine inhibited the activation of the PI3K/AKT signaling pathway both in vitro and in vivo, and suppressed the formation of renal fibrosis. Thus, the kokusaginine-mediated PI3K/AKT signaling pathway may represent a novel approach for the treatment of renal fibrosis.