[Acupuncture improves hepatic lipid metabolism by suppressing oxidative stress in obese nonalcoholic fatty liver disease rats].

OBJECTIVE

To investigate the effect of acupuncture of "Daimai"(GB26) on abdominal fat accumulation, lipid metabolism and hepatic oxidative stress in abdominal obese non-alcoholic fatty liver disease (NAFLD) rats.

METHODS

male SD rats were divided into 3 groups: normal diet (normal, ＝8), high fat diet control (model) and acupuncture (＝8/group in the latter 2 groups). The abdominal obese NAFLD model was established by feeding the rats with high fat diet for 12 weeks. EA (2 Hz/15 Hz, 1.5 mA) was applied to bilateral GB26 for 20 min, once every other day for 8 weeks. Rats of the model group were also restrained for 20 min as those in the EA group. The body mass and abdominal circumference were measured weekly, the isolated adipose tissues around the bilateral kidney and epididymis and the fresh liver were weighed. The contents of serum cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), glutamic oxaloacetic aminotransferase (AST) were detected by using an automatic biochemical analyzer. The abdominal visceral fat distribution was acquired by CT scanning. The oxidative stress indexes of the homogenated liver tissues, such as malondialdehyde (MDA) was assayed using sodium thiobarbital (TBA) method, and the activity of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) were assayed by using hydroxylamine method and colorimetric method respectively. The histopathological changes of the liver were observed after staining with hematoxylin-eosin (HE).

RESULTS

Following modeling, the body mass and waist circumference, visceral fat weight of bilateral kidneys and testis (visceral fat weight), liver weight, serum ALT, AST, TG and TC and liver MDA contents, were significantly higher in the model group (<0.001，<0.05), while hepatic T-SOD and GSH-PX activity was considerably lower in the model group than those in the normal group (<0.001). After acupuncture intervention, the levels of all the above-mentioned indexes (modeling induced both increase and decrease) were reversed relevant to the model group (<0.05, <0.01). The results of CT scanning showed that the fat accumulation area in the abdomen was 8.67 cm 18.51 cm and 13.75 cm in the normal, model and acupuncture groups, respectively, presenting a decrease after acupuncture. H．E. staining displayed that the degree of hepatic steatosis (including vague hepatic lobule boundary, disordered arrangement of hepatic cord, hepatocellular swelling, diffuse fatty degeneration, unequal-sized lipid droplets in the hepatocytes, nucleus excursion and dissolution after modeling) was improved after acupuncture.

CONCLUSION

Acupuncture can reduce body weight and abdominal fat accumulation in abdominal obese NAFLD rats, which may be related to its effects in inhibiting oxidative stress (lowering MDA level and increasing the activity of T-SOD and GSH-PX) and improving hepatic lipid metabolism.