Objective: To observe the effect of effective fractions of Huangqisan (HQS) on mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c) and its target genes in insulin-resistant HepG2 cells. Method: The effect of HQS on the activity of HepG2 cells was detected by methye thiazolye telrazlium(MTT) method. The model of insulin-resistant HepG2 cells was induced and established by high glucose and high insulin. While inducing the model

HepG2 cells were treated with different concentrations of HQS

and metformin (MET) was used for positive control. The glucose uptake of cells was detected by fluorescent D-glucose homologue (2-NBDG)

and the contents of total triglyceride(TG) and free fatty acids(FFA) in cells were also detected by assay kits. Meanwhile

intracellular lipid droplets were observed by oil red O staining. Besides

Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR) method was used to detect mRNA expressions of SREBP-1c

acetyl CoA carboxylase 1 (ACC1)

fatty acid synthase (FAS) and stearoyl-CoA desaturase 1(SCD1). Result: According to the findings of MTT experiment

three different concentrations 25 mg·L-1 (HQS-L)

50 mg·L-1 (HQS-M) and 100 mg·L-1 (HQS-H) of HQS were selected for treating cells

and the treating time was 24 h. Compared with control group

the glucose uptake of cells significantly decreased in model group (P<0.01)

and the contents of TG and FFA markedly increased (P<0.01). Besides

a large number of red vesicular lipid droplets were also observed in cytoplasm

and the mRNA expressions of SREBP-1c

ACC1

FAS and SCD1 all apparently up-regulated (P<0.01). Compared with model group

different concentrations of HQS all significantly increased the glucose uptake (P<0.05

P<0.01). HQS-H and HQS-M reduced the contents of TG and FFA in cells (P<0.01) and the number of intracellular lipid droplets. Meanwhile

HQS-L decreased FFA content (P<0.05). Besides

HQS-H apparently down-regulated the mRNA expressions of SREBP-1c

ACC1

FAS and SCD1 (P<0.05

P<0.01)

and HQS-M also down-regulated the mRNA expressions of SREBP-1c

FAS and SCD1 (P<0.05). Although HQS-M could also inhibit ACC1 mRNA expression

there was no statistically significant difference. Conclusion: HQS may alleviate insulin resistance in HepG2 cells by inhibiting SREBP-1c mRNA expression and reducing lipid synthesis.