Objective To observe the effect of magnesium isoglycyrrhizinate on the expressions of UGT1A, MRP2 protein and mRNA of L-02 cells damaged by triptolide, and to investigate hepatoprotective mechanism of magnesium isoglycyrrhizinate in terms of drug metabolism. Methods L-02 cells were divided into 4 groups:normal group, triptolide group, magnesium isoglycyrrhizinate group and rifampicin group. Magnesium isoglycyrrhizinate group and rifampicin group were pretreated by magnesium isoglycyrrhizinate and rifampicin for 24 h and the remaining two groups added medium. Triptolide were added for 18 h except normal group. Cell survival rate was tested by MTT. The expression levels of UGT1A, MRP2 protein and mRNA were detected by Western blot assay and RT-PCR. Results Compared with triptolide group, cell survival rate was significantly higher in magnesium isoglycyrrhizinate group (P<0.05). Meanwhile, the expression levels of UGT1A, MRP2 protein and mRNA were significantly lower in triptolide group compared with those of control group (P<0.05). The expression levels of UGT1A, MRP2 protein and mRNA were significantly up-regulated in magnesium isoglycyrrhizinate pretreatment group than those of triptolide group (P<0.05). The UGT1A protein and mRNA expressions were significantly decreased in rifampicin pretreatment group than those of magnesium isoglycyrrhizinate group ( P<0.05), but there were no significant differences in MRP2 protein and mRNA expressions between the two groups. Conclusion Magnesium isoglycyrrhizinate shows protective effects on triptolide induced L-02 cell injury, which may be involved with the activation of UGT1A and MRP2.

OBJECTIVE:To investigate the effects of Glycyrrhiza uralensis extract (GE) on the expression of uridine diphosphate glucuronyltransferase 1A (UGT1A) and multidrug resistance associated protein 2 (MRP2) in human liver L-02 cells damaged by triptolide (TP),and to study attenuated mechanism of G.uralensison for TP.METHODS:The survival rates of L-02 cells were determined by MTT assay after cultured with 0 (blank control),40,80,160 nmol/L TP for 12,18,24 h.L-02 cells were divided into blank control group (blank culture medium),model control group (80 nmol/L TP) and GE pretreatment group (adding 80 nmol/ L TP after pretreated with 30,60,90 mg/L GE for 24 h);after cultured for 18 h,survival rates of L-02 cells were determined by MTT assay.Rifampin (RIF) group (positive control,adding 80 nmoi/L TP after pretreated with 10 μmol/L RIF for 24 h) was added on the basis of the above grouping (GE concentration of 60 mg/L in GE pretreatment group).After cultured for 24 h,the protein expressions of UGT1A and MRP2 were detected.RESULTS:The inhibition effect of TP on cell proliferation was positively correlated with the concentration and the time.Compared with blank control group,cell survival rate of model control group was decreased significantly (P＜0.05),and the protein expression of MRP2 was decreased significantly (P＜0.01).Compared with model control group,cell survival rates of 30,60,90 mg/L GE pretreatment groups were all increased significantly (P＜0.01).The protein expressions of UGT1A and MRP2 were increased significantly in 60 mg/L GE pretreatment group (P＜0.01).CONCLUSIONS:GE pretreatment can relieve TP-induced human liver L-02 cell damage,and its attenuated mechanism may be associated with the increase the expression of UGT1A and MRP2.

OBJECTIVE： To observe the improvement effects of water extract of Glycyrrhiza uralensis on acute hepatic injury caused by triptolide and its effects on the levels of IL-10 and TNF-α in rats. METHODS： A total of 60 healthy male SD rats were randomized into blank control group， model group， positive control group （magnesium isoglycyrrhizinate） and G. uralensis water extract low-dose， middle-dose and high-dose groups. Blank control group and model group were given isochoric normal saline intragastrically； positive control group was given Magnesium isoglycyrrhizinate liquid intragastrically （13.5 mg/kg）； G. uralensis water extract low-dose， middle-dose and high-dose groups were given G. uralensis water extract intragastrically 1 mL （120， 240， 480 mg/kg， by the amount of extract）， qd， for consecutive 7 d. At 8th day of administration， model group， positive control group and G. uralensis water extract groups were given Triptolide liquid intragastrically （0.6 mg/kg） to establish acute liver injury model. HE staining was used to detect the pathological changes of liver tissue in rats. The activities of ALT and AST in serum were determined by enzyme coupling reaction. The protein expression of IL-10 and TNF-α in liver tissue were analyzed by Western blotting. RESULTS： Compared with blank control group， obvious pathological changes of liver tissue in rats were observed in model group； serum activities of ALT and AST， the protein expression level of TNF-α in liver tissue were increased significantly， while the protein expression level of IL-10 was decreased significantly （P＜0.01）. Compared with model group， pathological changes of liver tissue were relieved significantly. Except for the activity of AST in serum of rats in G. uralensis water extract low-dose group， the activities of ALT and AST in serum， the protein expression level of TNF-α in liver tissue were decreased significantly in G. uralensis groups， while the protein expression level of IL-10 in liver tissue was increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： G. uralensis water extract can relieve triptolide-induced acute liver injury in rats， the mechanism of which may be associated with expression down-regulation of pro-inflammatory factor TNF-α and expression up-regulation of anti-inflammatory factor IL-10.