Extraction Of Chlorogenic Acid From Sweet Potato Leaves And Its Regulation Of Glucose Metabolism Disorders

Chlorogenic acid is one of the main active components of sweet potato leaves and has biological activities such as anti-inflammatory,hypoglycemic and immunomodulatory functions.In this paper,sweet potato leaves were used as the raw material to be tested,and the extraction was carried out by ultrasonic method,and the effects of material-liquid ratio,ultrasonic time and ethanol concentration on the extraction rate of crude extract of chlorogenic acid from sweet potato leaves were compared,determination of the toxicity of crude extract of chlorogenic acid from sweet potato leaves as the compound to be tested and its effect in regulating disorders of glucose metabolism in primary hepatocytes and in acute animal mice assays,a comprehensive evaluation of the effect of chlorogenic acid from sweet potato leaves on improving the inhibition of hepatic gluconeogenesis by glucagon disorder in primary hepatocytes,acute animal mice and mice fed a high-fat diet model for a long period of time,using chlorogenic acid prepared from sweet potato leaves as the compound to be tested;we measured the regulation of inflammatory factor p38 and Akt/Fox O1 signaling pathway by Western Blot,and examined the changes of sweet potato leaf chlorogenic acid on the signaling pathway under the effect of glucagon,to provide new ideas for the therapeutic strategy of sweet potato leaf chlorogenic acid in clinical diabetes as well as to provide theoretical support for reducing the waste of sweet potato leaf resources,and to provide a theoretical basis for the development of health products or drugs related to the treatment of type 2 diabetes.The test results are as follows:1.Inhibition of glucagon-mediated hepatic gluconeogenesis by chlorogenic acid of sweet potato leavesThe experiment took the extraction rate of crude chlorogenic acid from sweet potato leaves as the evaluation index,explored the effect of single-factor test on the extraction rate of crude chlorogenic acid,optimized the best extraction conditions of crude chlorogenic acid from sweet potato leaves using response surface methodology,and compared the extraction of crude chlorogenic acid from sweet potato leaves under the conditions of different factors.In the single factor,the maximum extraction rate was 2.60% at 70% ethanol volume fraction;3.14% at 1:30 material-to-liquid ratio;and 2.94% at 30 min ultrasonic time.The influence of ethanol solution on the extraction rate of chlorogenic acid was the largest in the orthogonal experiment,followed by the material-liquid ratio,and the influence of sonication time was relatively small.The results of response surface experiments on the interaction of the factors showed that the material-liquid ratio vs.sonication time > material-liquid ratio vs.ethanol concentration > sonication time vs.ethanol concentration.The best extraction rate of 3.54%was obtained at 50 min of sonication,a feed-to-liquid ratio of 1:39 and an ethanol concentration of 65.48%.2.Mechanism of sweet potato leaf chlorogenic acid in regulating hepatic gluconeogenesisCrude extract of sweet potato leaf chlorogenic acid in primary hepatocytes MTT assay and hepatic glucose output assay showed that crude extract of sweet potato leaf chlorogenic acid could reduce glucose production in primary hepatocytes and significantly inhibit glucose production in primary hepatocytes at 10 μg/m L;in an acute pyruvate tolerance assay,crude extract of chlorogenic acid from sweet potato leaves significantly reduced the increase in blood glucose induced by sodium pyruvate.To verify whether the regulation of hepatic glucose xenobiotic by chlorogenic acid in crude extract of sweet potato leaves was regulated by chlorogenic acid,HPLC was performed to determine the content of chlorogenic acid in crude extract of sweet potato leaves,which proved that chlorogenic acid of sweet potato leaves had the effect of regulating hepatic glucose xenobiotic.In the MTT assay and glucose output assay,sweet potato chlorogenic acid was non-toxic to primary hepatocytes in the assay range and significantly inhibited glucagon-induced gluconeogenesis in primary hepatocytes at10 μM;amelioration of glucose elevation induced by glucagon or sodium pyruvate in mice given sweet potato leaf chlorogenic acid in acute animal experiments;in a mouse model of glucolipid metabolism disorder induced by long-term high-fat feeding,sweet potato leaf chlorogenic acid reduced fasting glucose and improved pyruvate tolerance and oral glucose tolerance in diet-induced obese mice,slowed body weight gain and reduced fat accumulation in the liver and epididymis of mice.A comprehensive evaluation of the inhibitory effect of sweet potato leaf chlorogenic acid on endogenous gluconeogenesis under the action of glucagon.3.Mechanism of hepatic gluconeogenesis regulation by chlorogenic acid in sweet potato leavesSweet potato leaf chlorogenic acid increased Akt phosphorylation in primary hepatocytes,livers of mice from acute animals injected intraperitoneally with glucagon,and livers of mice fed chronically with high fat,inhibited Fox O1 phosphorylation in response to Akt and failed to nucleate,and blocked transcriptional regulation of gluconeogenesis by glucagon;sweet potato leaf chlorogenic acid provides a reference for the regulation of the glucagon pathway by inhibiting the phosphorylation level of p38,which in turn promotes the phosphorylation of Fox O1,inhibits the nucleation of Fox O1,reduces the level of hepatic gluconeogenesis,and establishes a link between the hepatic glucagon response and the inflammatory response.