Fermented Barley Extracts with Lactobacillus plantarum dy-1 Rich in Vanillic Acid Modulate Glucose Consumption in Human HepG2 Cells.

OBJECTIVE: To investigate the effect of fermented barley extracts with Lactobacillus plantarum dy-1 (LFBE) for modulating glucose consumption in HepG2 cells via miR-212 regulation. METHODS: Hepatocellular carcinoma (HepG2) cells were treated with palmitate. After 12 h, palmitate-induced HepG2 cells were treated with LFBE and its main components. Changes in glucose consumption, proinflammatory cytokine secretion, and miRNA-212 expression in HepG2 cells was observed. RESULTS: Treatment with LFBE rich in vanillic acid (VA) increased glucose consumption and reduced proinflammatory cytokine secretion in HepG2 cells. LFBE and VA normalized the upregulation of miR-212, which led to the upregulation of dual-specificity phosphatase-9 (DUSP9), a direct target of miR-212, at both protein and mRNA levels. Downregulation of miR-212 markedly increased glucose consumption and reduced proinflammatory cytokine secretion by enhancing DUSP9 expression. CONCLUSION: The results showed the benefit of LFBE and miR-212 downregulation in modulating glucose consumption and reducing proinflammatory cytokine secretion by targeting DUSP9. VA in LFBE was a strong regulator of palmitate-induced abnormal glucose consumption in HepG2 cells and can be a primary mediator.