Corilagin Counteracts IL-13Rα1 Signaling Pathway in Macrophages to Mitigate Schistosome Egg-Induced Hepatic Fibrosis.

The IL-13Rα1 signaling pathway and M2 macrophages play crucial roles in schistosome egg-induced hepatic fibrosis via the expression of pro-fibrotic molecules. This study aims to investigate the inhibitory effect and mechanism of action of corilagin on schistosome egg-induced hepatic fibrosis via the IL-13Rα1 signaling pathway in M2 macrophages in vitro and in vivo. The mRNA and protein expression of IL-13Rα1, PPARγ, KLF4, SOCS1, STAT6, p-STAT6, and TGF-ß was measured in vitro with corilagin treatment after IL-13 stimulation and in vivo corilagin treatment after effectively killing the adult schistosomes in schistosome-infected mice. Histological analysis of liver tissue was assessed for the degree of hepatic fibrosis. The results revealed that corilagin significantly reduced the expression of PPARγ, KLF4, SOCS1, p-STAT6, and TGF-ß compared with model group and praziquantel administration (p < 0.01 or p < 0.05) in vivo and in vitro, which indicated a strong inhibitory effect of corilagin on IL-13Rα1 signaling pathway. As well, the inhibitory effect of corilagin showed a significant dose-dependence (p < 0.05). The area of fibrosis and distribution of M2 macrophages in mouse liver tissue were reduced significantly and dose-dependently with corilagin treatment compared to model group or praziquantel administration (p < 0.01 or p < 0.05), indicating that corilagin suppressed IL-13Rα1 signaling pathway and M2 macrophage polarization effectively in vivo. Furthermore, the anti-fibrogenic effect persisted even when IL-13Rα1 was up- or down-regulated in vitro. In conclusion, corilagin can suppress schistosome egg-induced hepatic fibrosis via inhibition of M2 macrophage polarization in the IL-13Rα1 signaling pathway.

Mechanism of Corilagin interference with IL-13/STAT6 signaling pathways in hepatic alternative activation macrophages in schistosomiasis-induced liver fibrosis in mouse model.

This study tried to find the mechanism of Corilagin interference with interleukin (IL)-13/signal transducer and activator of transcription (STAT) 6 signaling pathways in IL-13-activated liver alternative activation macrophages in schistosomiasis-induced liver fibrosis in Balb/c mice. As a result, IL-13 in serum and the mRNA expression of IL-13 Receptor α1, IL-4 Receptor α and downstream mediators supressor of cytokine signaling (SOCS) 1, Kruppel-like factor (KLF) 4, peroxisome proliferator-activated receptor (PPAR) δ in the liver tissue were significantly inhibited by Corilagin (P<0.05 or 0.01). The protein expression of IL-13 Receptor α1, IL-4 Receptor α, SOCS1, KLF4, PPARγ, PPARδ and Phospho-STAT6 (P-STAT6) in Corilagin group were also markedly suppressed when compared with the model group (P<0.05 or 0.01). Furthermore, the inhibitory effect was enhanced when the concentration of Corilagin increased (P<0.05). By hematoxylin and eosin (HE) staining, when compared with the model group, the Corilagin group showed smaller granulomas (P<0.05 or 0.01). The area of positive cells and integrated optical density (IOD) of CD68, CD206 and KLF4 was significantly decreased by Corilagin stained by IHC (P<0.05 or 0.01). In conclusion, Corilagin had potential to relieve hepatic fibrosis caused by egg granuloma in Schistosoma japonicum infection by decreasing the expression of molecules associated with IL-13/STAT6 signaling pathway in liver alternative activation macrophages.

Effect of Corilagin on the miR-21/smad7/ERK signaling pathway in a schistosomiasis-induced hepatic fibrosis mouse model.

This study sought to investigate the anti-fibrotic effect of Corilagin via interference with the miR-21/smad7/ERK signaling pathway in a schistosomiasis-induced hepatic fibrosis mouse model. Mice were infected with Schistosoma japonicum cercaria to establish the mouse model of schistosomiasis-induced hepatic fibrosis. At four weeks after infection, the groups were given different medications. The living conditions were observed. Real-time PCR was employed to detect the mRNA levels of miR-21, smad7 and connective tissue growth factor (CTGF), and western blotting was used to examine the protein levels of smad7, CTGF, smad1, p-smad1, smad2, p-smad2, ERK1/2, p-ERK1/2 and TGF-ß receptor I. Immunohistochemistry was used to examine the expression of CTGF. Compared with the model group, increasing concentrations of Corilagin improved the quality of life, inhibited the mRNA expression of miR-21, promoted smad7 protein expression, and inhibited CTGF protein expression (p<0.05 or 0.01). Moreover, Corilagin significantly reduced the protein levels of p-smad1, p-smad2, p-ERK1/2, and TGF-ß receptor I (p<0.05 or 0.01). CTGF staining in the cytoplasm was markedly decreased by Corilagin (p<0.05 or 0.01). In conclusion, Corilagin inhibited schistosomiasis-induced hepatic fibrosis via the miR21/smad7/ERK pathway in this animal model.