A Preliminary Study On The Intervention Of Green Tea Polyphenols On Hyperlipidemia In Caniness

Objective: Hyperlipidemia is a metabolic disease and characterised by one or more serum lipids which beyond the normal range,including increased total cholesterol,triglycerides,low-density lipoprotein cholesterol and decreased high-density lipoprotein cholesterol.Previous studies have found that tea polyphenols play an important role in preventing and improving hyperlipidemia in livestock and poultry.However,it is not sure that if GTPs can interfere with hyperlipidemia in canines.Canines were selected to study the intervention effect of GTPs on hyperlipidemia.Method: Thirty 13-14 months old male Beagles with similar body weights,identical parity and clinical health were selected.Canines were fed with low fat diet for 1 month and randomly divided into 5 groups(6 canines in each group): Low fat group was fed the low fat diet,high fat group was fed high fat diet and 0.48%,0.96% and 1.92% GTPs groups were fed high fat diet containing different concentrations(0.48%,0.96% and 1.92%)of GTPs.All canines were free to feed and drink.All canines were weighed and blood were collected for obtaining serum after fasting for 12 hours.The trial was lasted for 18 weeks.Index of lipid metabolism,liver function and renal function was measured by automatic biochemical analyzer method.On the end of the trial,4 canines were randomly selected from each group and injected with Lu Mianning(0.1 mL/kg)accord to body weight.Body length was measured to calculate Lee index.Weight of Liver,perirenal fat and epididymal fat were weighed to calculate liver coefficient and abdominal fat coefficient.Liver tissue was collected for pathological changes observation and fatty acid composition determination and adipose tissue was collected for observing pathological changes.Results:(1)At the end of the trial,Lee index in high fat group was significantly higher than in low fat group(P<0.05)and in all GTPs groups was lower than in high fat group.Lee index in 0.96% and 1.92% GTPs groups was significantly lower than in high fat group(P<0.05).Subcutaneous fat thickness in high fat group was higher than in low fat group and in all GTPs groups was lower than in high fat group.Subcutaneous fat thickness in 0.48% and 1.92% GTPs groups was significantly lower than in high fat group(P<0.05).Liver weight in high fat group was higher than in low fat group and in all GTPs groups was lower than in high fat group.Liver weight in 1.92% GTPs group was significantly lower than in high fat group(P<0.05).Liver coefficient in high fat group was higher than in low fat group and in 0.96% and 1.92% GTPs groups was lower than in high fat group.Abdominal fat weight in high fat group was higher than in low fat group and in 0.96% and 1.92% GTPs groups was lower than in high fat group.Abdominal fat weight in 1.92% GTPs group was significantly lower than in high fat group(P<0.05).Abdominal fat coefficient in high fat group was significantly higher than in low fat group(P<0.05)and in all GTPs groups was lower than in high fat group.Abdominal fat coefficient in 1.92% GTPs group was significantly lower than in the high fat group(P<0.01).Body weight and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and in all GTPs groups was lower than in high fat group.(2)At the end of the trial,serum TC and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and in all GTPs groups were lower than in high fat group.Serum TG and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and in all GTPs groups were lower than in high fat group.Serum LDL-C and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and in all GTPs groups were lower than in high fat group.Serum HDL-C in high fat group was significantly lower than in low fat group(P<0.05)and its decrease rate was higher.Serum HDL-C and its increase rate in all GTPs groups were higher than in high fat group.Serum TP and its increase rate in high fat group were significantly lower than in low fat group(P<0.05)and in all GTPs groups were higher than in high fat group.Serum ALB and its increase rate in high fat group were lower than in low fat group and its increase rate in all GTPs groups was higher than in high fat group.Serum GLB and its increase rate in high fat group were lower than in low fat group and its increase rate in all GTPs groups was higher than in high fat group.Serum GLB in 0.48% and 0.96% GTPs groups was higher than in high fat group.Serum ALB/GLB in high fat group was lower than in low fat group and its decrease rate was higher.Serum ALB/GLB in all GTPs groups was higher than in high fat group and its decrease rate was lower.Serum ALT and its increase rate in high fat group were significantly in higher than in low fat group(P<0.05)and in all GTPs groups were lower than in high fat group.Serum ALT in 0.48% and 0.96% GTPs group were significantly lower than in high fat group(P<0.01,P<0.05).Serum AST and its increase rate in high fat group were higher than in low fat group and in all GTPs groups were lower than in high fat group.Serum AST/ALT and its increase rate in high fat group were higher than in low fat group and in all GTPs groups were lower than in high fat group.Serum GGT and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and serum GGT in all GTPs groups was lower than in high fat group.Increase rate of serum GGT in 0.48% and 0.96% GTPs groups was lower than in high fat group.Decrease rate of serum GGT in 1.92% GTPs groups was higher than in high fat group.Serum ALP and its increase rate in high fat group were higher than in low fat group and in all GTPs groups were lower than in high fat group.Serum LDH and its increase rate in high fat group were significantly higher than in low fat group(P<0.05)and in all GTPs groups were lower than in high fat group.Serum Urea and its increase rate in high fat group were higher than in low fat group and in all GTPs groups were lower than in high fat group.Serum Crea and its increase rate in high fat group were significantly higher than in low fat group(P <0.01)and in all GTPs groups were lower than in high fat group.Serum Crea in 1.92% GTPs group was significantly lower than in high fat group(P<0.05).Serum Glu and its increase rate in high fat group were higher than in low fat group and in all GTPs groups were lower than in high fat group.Serum Glu in 1.92% GTPs group was significantly lower than in high fat group(P<0.05).(3)HE staining trial,hepatocytes in low fat group were uniform in size,and hepatic cords were arranged regularly.Hepatocytes in high fat group were swollen and degenerate,and hepatic cords were disordered.Hepatocytes swelling and hepatic cords disordering were improved in all GTPs groups.Adipocytes in low fat group were uniform in size,and gaps between adipocytes were clear.Adipocytes were increased in size,and gaps between adipocytes were disappeared in high fat group and these changes were improved in all GTPs groups.(4)14 SFA,8 MUFA and 9 PUFA were detected in liver fatty acid composition trial.Relative content of SFA in high fat group was higher than in low fat group and in 0.48% and 0.96% GTPs groups was lower than in high fat group.Relative content of MUFA and PUFA in high fat group was lower than in low fat group and in 0.48% and 0.96% GTPs groups was higher than in high fat group.Relative content of C20:2 in high fat group was significantly lower than in low fat group(P<0.05).Relative content of C15:1 and C22:6N3 in 1.92% GTPs group was significantly higher than in high fat group(P<0.05).