Hypoglycemic Effect And Its Mechanisms Of The Mulberry Branch Phloem Extracts In Vivo

In this experiment, we used mulberry branches (Ramulus mori) as experimentalmaterials, acquired the bark extracts of mulberry branches with aqueous alcoholsolution as the extraction solvent, explored its α-glycosidase inhibitory activity invitro and discussed the difference of the inhibitory activity in different parts orvarieties of mulberry. Application of molecular biological methods to explore thetherapy effect of mulberry branch bark extract on diabetes mice and the mechanism ofregulate blood glucose.α-glycosidase inhibitory activity of different parts extracts from three varietiesmulberry of analysis showed that the mulberry leaf extracts had low α-glycosidaseinhibitory activity, while mulberry branches bark and mulberry root bark extracts hadhigh α-glycosidase inhibitory activity, and widely planted HuSang32branch barkextracts strongly inhibited α-glucosidase activities whose IC50value was2.01μg/mL.The results of101mulberry varieties α-glycosidase inhibitory activity showed thatdifferent mulberry varieties had different α-glycosidase inhibitory activity. HuSang32branch bark extracts also had a strong scavenging activity of1,1-diphenylphenylhydrazine free radicals (DPPPH), and its scavenging activity enhanced with itsconcentration increased whose IC50value was0.53mg/mL.1-deoxynojirimycin(DNJ) is an effective inhibitor of α-glycosidase, the result showed that the DNJcontent of20kinds mulberry branch bark extracts were in the range of0.44~9.79mg/g with HPLC analysis method. The results showed that the content of DNJ and itsinhibitory activity of α-glucosidase of the mulberry branch bark extract had noobvious relevance, with a correlation coefficient R=0.0085only. That is to say, thestrong α-glycosidase inhibitory activity of mulberry branch bark could be own toother component, such as flavonoid, Coumarin, Morusin, Stilbenes or other alkaloidscompounds.In vivo animal experiment results showed high fat and sugar diet can significantly increase the incidence of diabetes (90%) in mice induced bystreptozotocin (STZ). When mice diet contained2.5%,2.5%or5%feed of mulberrybranch bark powder with high fat and sugar for2weeks, and then to start STZinduced diabetic mice experiment, the results show that adverse effects caused byhigh fat and sugar in mice can basically eliminated with different doses of mulberrybranch bark powder. And HuSang32mulberry branch bark power can reduce theincidence of diabetes in high fat and sugar diet mice induced by streptozotocin (STZ),the protective effect of high dose treatment group is most significantly with an only50%incidence.Oral administration mulberry branch bark extract to diabetic mice induced bySTZ for three weeks, the results showed that HuSang32mulberry branch bark extractcan improve the weight gain and the Swelling of Liver and kidney in diabetic mice. Itcan also reduce the serum insulin levels, improve insulin resistance, and regulatedyslipidemia in STZ-induced diabetic mice. HuSang32mulberry branch bark extractcan regulate the expression of the glycometabolism related genes mRNA such asG6Pase GCK, PEPC in the liver of diabetic mice, as so as to regulate sugarmetabolism, reduce blood glucose level in mice. And it can improve the mRNAexpression product of the insulin secretion related genes Ins1, Ins2, PDX-1whichregulates the secretion of insulin, decrease the insulin resistance in diabetic mice.The results of those experiments provided an important basis for the full use andhigh value biological medical drugs development of mulberry branch, which is thelargest agricultural waste in sericulture in China.