ABSTRACT
ObjectiveThis study aimed to investigate the effects of eugenol on inhibiting the inflammatory activation of human umbilical cord mesenchymal stem cells （HUC-MSCs） and the pro-inflammatory phenotype of hepatic stellate cells （HSCs） in liver fibrosis， and to explore their underlying mechanisms. MethodsHUC-MSCs were cultured and identified in vitro， and the toxicity of eugenol to HUC-MSCs was evaluated by MTT method. The effect of eugenol on the migration ability of HUC-MSCs was investigated by in vitro scratch test. The expression of α-SMA， COL1A1， Smad2/3 and p-Smad2/3 of LX-2 cells activated by TGF-β1 treated with EU-MSCs-CM and MSCs-CM were detected by WB assay. EU-MSCs-CM and MSCs-CM treated THP-1 macrophages stimulated with Lipopolysaccharide （LPS） were analyzed for the expression of surface markers CD11b， CD86， and CD206 by flow cytometry. Additionally， the expression of pro-inflammatory genes TNF-α， IL-1β， and IL-6 in THP-1 macrophages was detected by qPCR. ResultsThe results of MTT method showed that the viability of the cells remained above 90% after 24 h and 48 h treatment at 0， 7.5， 15 μg/mL. In vitro scratches showed that eugenol treatment enhanced HUC-MSCs migration. WB results showed that compared with MSCs-CM treatment， EU-MSCs-CM treatment significantly inhibited the expression of α-SMA， COL1A1， Smad2/3， and p-Smad2/3 of activated HSCs. Flow cytometry showed that compared with MSCs-CM treatment， EU-MSCs-CM treatment had a more significant inhibitory effect on CD86， a M1-type polarization marker in THP-1 macrophages. The results of qPCR experiment showed that compared with MSCs-CM treatment， EU-MSCs-CM treatment more significantly inhibited the expressions of TNF-α， IL-1β and IL-6 of THP-1 macrophage proinflammatory genes. ConclusionsEugenol enhances the inhibitory effect of HUC-MSCs on inflammatory activation of HSCs， possibly by regulating TGF-β1/Smads signaling pathway. It also enhances the inhibitory effect of HUC-MSCs on the pro-inflammatory phenotype of macrophages. Proinflammatory macrophages can promote inflammatory activation of HSCs.