[Effect of diammonium glycyrrhizinate and phospholipids complex oninflammatory gene expression induced by palmitic...

Objective: To investigate the effect of glycyrrhizinate and phospholipids (DGPL) complex on inflammatory gene expression in cell inflammation model induced by palmitic acid (PA). Methods: Huh7 cells were divided into control, PA and PA+DGPL groups. For control group, cells were treated with BSA; for PA group, cells were incubated with 0.2 mmol/L saturated fatty acid PA, PA+DGPL group was given 20 μmol/L or 100 μmol/L DGPL in addition to 0.2 μmol/L PA. After 24 h, the expression of inflammation-related genes COX-2 and iNOS and endoplasmic reticulum (ER) stress-related gene GRP78 was determined by RT PCR. Oil red staining was conducted to observe the effect of DGLP on steatosis. Results: Compared with control group, the expression of COX-2, iNOS and GRP78 in PA group was enhanced to 6.07±0.73(P<0.05), 3.18±0.91 (P<0.01) and 3.21±1.00(P<0.05), respectively. Compared to control group, the expression of COX-2,iNOS and GRP78 in 100 μmol/L DGPL group was reduced to 2.40±0.76, 1.60±0.49 and 1.17 ±0.42 (P<0.05); and 20 μmol DGPL had similar inhibition effect on COX-2 and iNOS elevation induced by PA (P<0.01, P<0.05 respectively). In addition, DGLP enhances the steatosis of Huh7 cells as demonstrated by oil red staining. Conclusion: PA can induce the up-regulated expression of inflammation associated genes COX-2, iNOS and ER stress-associated gene GRP78 in Huh7 cells. DGPL is able to protect Huh7 cells from PA induced inflammatory gene expression and the beneficial effect may be partially due to its unsaturated phospholipid component, which may improve ER stress and enhance steatosis.