The Prevention Effect Of Ellagic Acid On High-fat Diet-induced Obesity In Rats

Objective:To investigate the preventional effect of ellagic acid on obesity and the underlying mechanism of prevention of obesity by intervention of ellagic acid on high fat diet induced obesity.Methods:According to body weight,Fifty six male SD rats were randomly divided into 7 groups as follows:rats fed with normal diet,rats fed with high fat diet,rats fed with high dosage of Ellagic Acid(30 mg/kg),rats fed with low dosage of Ellagic Acid(10 mg/kg),rats fed with Metformin Hydrochloride Extended-release Tablets(89.25 mg/kg),rats fed with Orlistat Capsules(37.8 mg/kg)and rats fed with Tiopronin enteric-coated tablets(47.25 mg/kg).Fedding with high fat diet and corresponding intervention after fed with basal diet for 1 week;the body weight was measured once a week,food intake was measured twice a week and the body length was measured at weeks 12 and 25.respectively;to analyze blood glucose levels by intraperitoneal injection of glucose solution and insulin,respectively at weeks 25;the thickness of the fat layer in the middle of the kidney cross section was measured by an ultrasonic diagnostic apparatus;to measure the levels of HDL-C,LDL-C,TC and TG in serum;the adipocyte morphology of the adipose tissue of the epididymis and perineum was observed by HE staining,and calculate the WAT index;removing the liver to calculate the liver index and observe the liver cells by HE staining;the protein expression levels of PPAR-γ,C/EBP-β,C/EBP-a,UCP-1 and PGC-1a in white adipose tissue of epididymis were detected by Western blot.Results:1.the weight of HF+HDEA(417.06±42.93),HF+LDEA(395.61±30.83),HF+DMBG(412.07±49.26)HF+Orl(408.09±52.18),HF+Tio(395.93±63.43)group was significantly lower than that of the HFD group(559.45±59.46)(p<0.05);but the average daily intake of rats was no different among groups(p>0.05);2.After intraperitoneal injection of glucose solution,the blood sugar level at 30 min and AUC of HF+HDEA(127.13±27.82,12423.38±1299.97)and HF+LDEA(121.63±7.84,12412.29 ± 872.91)in rats was significantly improved compared with the HFD(158.63±6.00,13982.63±933.17)(p<0.05);3.The levels of HDL-C in the HF+HDEA(3.97±0.42)and HF+LDEA(3.51±0.38)were significantly higher than that in the HFD group(2.9±0.59)(p<0.05);4.After intervention,compared with the HFD group(0.22±0.03),the thickness of peritumoral fat of HF+HDEA(0.05±0.01)and HF+LDEA(0.06±0.03)were decreased significantly(p<0.05);compared with the HFD group(4.26±0.19),the WAT index of the rats in the HF+HDEA(1.96±0.16)and HF+LDEA(2.08±0.13)were.decreased significantly(p<0.05);the pathological changes of WAT in the epididymis,BWT in the scapular and liver were observed under light microscope,and results reveal EA could effectively inhibit the accumulation of WAT,improve the function of BAT,and have a certain protective effect on liver.5.Compared with the HFD group(0.44±0.06,0.45±0.04,0.50±0.09),the protein expression level of PPAR y(0.22±0.01),C/EBP-β(0.25±0.09)and C/EBP-a(0.20±0.06)was significantly lower(p<0.05);but the protein expression levels of UCP-1(0.38±0.05)and PGC-la(0.43±0.08)was significantly improved(p<0.05)in epididymal adipose tissue of HF+HDEA.Conclusion:Ellagic acid has a good effect on hypoglycemic,can improve insulin resistance,reduces the accumulation of WAT,reduces the expression of key proteins in lipid synthesis while increases the expression of brown fat marker protein,promotes white adipose tissue brownish,and then prevents high fat-diet induced obesity in rats.