Study On Hypoglycemic Activity Of Mulberry Twigs Compound

Diabetes mellitus is a complex group of chronic lifelong metabolic diseases with high disability and mortality.Most of the drugs used for this disease in the clinical treatment are chemosynthesis,which are expensive and long-term use have side effects.Therefore,the development of afordable,safe and efficient hypoglycemic agents from traditional hypoglycemic Chinese medicinal materials is a current research focus.Mulberry twigs are a traditional hypoglycemic medicinal material and a by-product of the sericulture industry.The further development and utilization of its hypoglycemic function are of great significance.The current research on hypoglycemic activity mainly focuses on alkaloids and their α-glucosidase inhibitory effects.The compound preparation can act on multiple pathways and targets at the same time,and has the advantages of enhancing curative effect and reducing side effects.In view of this,this study used mulberry twig,astragalus,momordica charantia,and corn silk as raw materials,and designed a compound formula based on the evaluation and screening of its hypoglycemic activity including enzyme inhibitory activity,free radical scavenging activity and in vitro cell test.Then the animal model was used to evaluate the hypoglycemic effect of the compound.The specific research contents and results are as follows:1.Screening for the hypoglycemic activity based on enzyme inhibitory activity and free radical scavenging ability.Alpha-glucosidase and PTP-1B enzyme(Protein Tyrosine Phosphatase1B)are important targets in the treatment of diabetes,and oxidative stress is almost involved in the entire occurrence and development of diabetes.The experiments of enzyme inhibition activity and free radical scavenging activity are simple and time-saving,and are suitable for the study of a large number of samples.In this study,the total extracts,alcohol extracts and water extracts of the prepared mulberry twigs,astragalus,momordica charantia and corn silk were evaluated for α-glucosidase and PTP-1B enzyme inhibitory activity,scavenge DPPH(1,1-diphenyl-2-picrylhydrazyl),ABTS(Diammonium 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate))and hydroxyl radical activities were evaluated.Then,the extracts with better activity were screened,which were mulberry twig total extract(MT-t),mulberry twig alcohol extract(MT-e),and astragalus ethanol extract(AST-e),astragalus water extract(AST-w),total extract of momordica charantia(MC-t),total extract of corn silk(CS-t),alcohol extract of corn silk(CS-e),corn silk water extract(CS-w).2.Cell-based screening for hypoglycemic activityInsulin resistance is the most commonly characteristic of type 2 diabetes.The digestion and absorption site of carbohydrates in food is mainly in the small intestine.Using cell models to screen extracts with hypoglycemic activity has the advantages of rapidity,simplicity and cost savings.Therefore,this part uses the insulin resistance model(IR-Hep G2)and the Caco-2 cell model were used to test the improvement of insulin resistance and glucose absorption of the extracts which were screened in the first part.Then,MT-t,AST-e,MC-t and CS-t which showed excellent hypoglycemic activity at the cellular level were screened for compound formulation.3.Hypoglycemic compound designThere are many targets for the treatment of diabetes,and the combined use of Chinese herbal medicines with hypoglycemic effect can exert the effect of lowering blood sugar in multiple targets,enhancing the curative effect,and reducing the side effects.In this part,based on the results of the first and second parts,takingα-glucosidase inhibitory activity and hydroxyl radical scavenging ability as indicators,the method of orthogonal t value was used to analyze the main drugs and the interaction of adjuvant.The four selected compound formulations were evaluated for their hypoglycemic effects based on enzyme inhibitory activity,free radical scavenging activity and cellular level.The research results show that the main drugs of the compound are MT-t and AST-e,and the auxiliary drugs are MC-t and CS-t,and the two have a synergistic effect;the compound ratio is determined as: MT-t: AST-e: MC-t:CS-t=4:3:2:1.4.Evaluation of hypoglycemic activity of compound at animal levelThe complexity of animal model is similar to the human body.The evaluation of hypoglycemic activity in animal is an essential link in the development of hypoglycemic biological products,and it is also of more practical significance.In this part,high-fat diet combined with streptozotocin(HFD/STZ)was used to induce mice to establish a type II diabetes model,and further evaluated the hypoglycemic effect of compound in vivo.Compared with the model group,the compound treatment group(0.5,1.0,2.0 g/kg/d)could reduce the blood sugar level of mice;alleviate the problem of weight loss caused by diabetes,and reduce the levels of serum transaminases,triglycerides and total cholesterol,increased the content of high-density lipoprotein and cleared the oxidative stress product malondialdehyde.The results of histopathologic observations showed that the compound could reduce the inflammatory infiltration and cell necrosis in the liver and kidney tissue of diabetic mice.Intestinal flora analysis revealed that at the phylum level,the relative abundance of Firmicutes was decreased in the treatment groups,the relative abundance of the beneficial bacteria phyla Bacteroidota and Verrucomicrobiota were increased,the B/F ratio which related to glucose metabolism was imporved.At the genus level,the intestinal hypoglycemic beneficial bacteria Muribaculaceae＿norank and Akkermansia were up-regulated,and the relative abundance of the diabetes pathogenic bacteria Lachnospiraceae NK4A136 group was decreased.The above results showed that compound has a good hypoglycemic effect in vivo.It could reduce the transaminase levels,the blood lipid levels and the oxidative stress levels in the body,and its effects were related to the protection of liver and kidney and the regulation of intestinal flora.In conclusion,the mulberry twig compound composed of MT-t,AST-e,MC-t and CS-t showed significant hypoglycemic activity.Our research provides a scientific basis for the development of hypoglycemic health food and medicine,and also provides a reference for the development and utilization of mulberry twigs,astragalus,bitter gourd and corn silk.