Study on the improvement effects and mechanism of Phyllanthus emblica water extracts on insulin resistance and lipid metabolism disorder in diabetic model rats / 中国药房

ABSTRACT

OBJECTIVE To investigate the improvement effects and possible mechanism of Phyllanthus emblica water extracts on lipid metabolism disorder and insulin resistance （IR） in diabetic model rats. METHODS IR model of male SD rats was established and randomly divided into model group， positive control group， P. emblica water extracts high-dose， medium-dose and low-dose groups， and another blank group was set up， with 10 rats in each group. P. emblica water extracts high-dose， medium- dose and low-dose groups were given P. emblica water extract diluent at the doses of 800， 400 and 200 mg/kg respectively； positive control group was given pioglitazone solution 2.7 mg/kg； blank group and model group were given the same volume of normal saline， by intragastrical administration， once a day， for consecutive 4 weeks. The general state of rats was observed， and the body mass and the levels of serum lipid metabolism indexes [triacylglycerol （TG）， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）] were measured； fasting insulin of serum （FINS）， insulin resistance index （IRI） and insulin sensitivity index （ISI） were measured and calculated by enzyme-linked immunosorbent assay （ELISA）. The pathological morphology of liver tissue was observed by hematoxylin-eosin staining； the expression of glycogen in the liver was observed by periodic acid-Schiff staining， and the staining area was calculated； the protein expressions of peroxisome proliferator-activated receptor γ （PPARγ）， nuclear factor κB（NF-κB） and AMP-activated protein kinase （AMPK） were detected by Western blot. RESULTS Compared with blank group， the rats in the model group had obvious symptoms of polydipsia， polyphagia and polyuria， and the serum levels of TC， TG， LDL-C， FINS and IRI were significantly increased （P＜0.05）， while ISI was significantly reduced （P＜ 0.05）； the structure of hepatic lobule was obviously disordered， the liver cells were deformed and enlarged， and there were many lipid deposits and fat vacuoles； PAS staining area of glycogen was significantly reduced（P＜0.05）； the protein expression levels of PPARγ and p-AMPK were significantly decreased （P＜0.05）， while the protein expression level of NF-κB was significantly increased （P＜0.05）. Compared with model group， the mental state of rats， liver histopathological morphology and glycogen expression were improved significantly in P. emblica water extracts high-dose and medium-dose groups； the levels of the above indicators were significantly reversed（P＜0.05）. CONCLUSIONS P. emblica water extracts may improve glucose and lipid metabolism disorders， liver function and IR in IR model rats， and regulate IR by activating the PPARγ/AMPK/NF-κB signaling pathway.