Curcumin reorganizes miRNA expression in a mouse model of liver fibrosis.

Curcumin (CM), a biphenyl compound, possesses anti-inflammatory, antioxidant and antimicrobial activity. MicroRNAs (miRNAs) are small noncoding RNAs which regulate gene expression and the molecular mechanisms of several biological processes. Liver fibrosis is a major cause of hepatic dysfunction and cancer and there are few effective therapies emphasizing the need for new approaches to control. The present study was conducted to investigate the effect of curcumin (CM) on liver fibrosis through modulating the expression level of miRNAs (199 and 200), the main miRNAs associated with liver fibrosis. Induction of liver fibrosis by carbon tetrachloride (CCL4) was confirmed by histopathological examination. Mice were divided into 3 groups: group 1 were i.p injected with 10% CCL4 twice weekly for 4 weeks and then once a week for the next 4 weeks followed by 4 weeks with olive oil only. Group 2 were i.p injected with 10% CCL4 twice weekly for 4 weeks and then once a week for the next 4 weeks followed by curcumin (5 mg/mouse/day) once daily for the next 4 weeks. The third group was injected with olive oil. The expression level of miR-199 and miR-200 and some of their targeted genes were measured by real time PCR. miRNA (199 and 200) levels were significantly elevated in liver fibrotic tissues compared to control groups. Curcumin was significantly returned the expression levels of mir-199 and -200 with their associated target gene nearly to their normal levels. This is the first study that highlighted the effect of curcumin on liver fibrosis through regulation of miRNAs.