Optimization of Extraction Technology of Total Flavonoids Psidium guajava Leaves by Box-Behnken Design-Response Surface Method and the Effects of Total Flavonoids on Glucose Tolerance in Diabetic Model Mice / 中国药房

OBJECTIVE:To optimize the extraction technology of total flavonoids from Psidium guajava leaves and investigate the effects of total flavonoids from P guajava leaves on glucose tolerance in diabetic model mice.METHODS:Based on single factor test,using extraction time,solid-liquid ratio and the amount of ethanol as independent variables,comprehensive scores of the yield of hyperin,quercetin-3-O-β-D-arabinopyranoside,quercetin-3-O-α-L-furanarabino side ethyl acetate and extract as dependent variable,Box-Behnken design-response surface method was used to optimize the reflux extraction process of total flavonoids from P guajava leaves,and validation test was also conducted.Sixty mice were randomly divided into blank group,model group,metformin group (170 mg/kg),P.guajava leaves total flavonoids low-dose,medium-dose and high-dose groups (23.41,46.81,93.62 mg/kg,by the content of total flavonoids),with 10 mice in each group.Except for blank group,diabetic model was induced in those groups,and then model mice were given relevant medicine intragastrically once a day for consecutive 21 d,6 h after last medication given glucose 2.0 g/kg intragastrically.The levels of blood glucose were determined 0,0.5,1.0,2.0 h after intragastric administration of glucose,and the area under the curve (AUC) of blood glucose was calculated.RESULTS:The optimal technology of P guajava leaves total flavonoids was as follows as extracting twice,lasting for 1.0 h each time,solid-liquid ratio of 1 ∶ 17,ethanol volume fraction of 56％.In validation test,the contents of hyperin,quercetin-3-O-β-D-arabinopyranoside and quercetin-3-O-α-L-furanarabino side ethyl acetate were 2.57,3.38,2.26 mg/g(RSD＜2％,n=3);the yield of extract was 25.71％ (RSD=1.19％,n=3);average comprehensive score was 96.41 (RSD=l.34％,n=3);relative error was 3.57％ with the predicted value of 99.98.Compared with blank group,AUC of mice were increased significantly in each group;compared with model group,AUC of metformin group,P.guajava leaves total flavonoids medium-dose and high-dose groups were all decreased significantly,with statistical significance (P＜0.05 or P＜0.01).CONCLUSIONS:The optimal extraction technology is stable,feasible and controllable in quality.Total flavonoids from P.guajava leaves can promote the recovery to normal level of blood glucose.

Construction of type 1 diabetic KM mice model induced by single high dose and multiple low dose of streptozotocin / 中国生化药物杂志

Objective To explore an optimal method of producing STZ-induced type 1 diabetic KM mice model by investigating the molded rate of single high dose and multiple low dose of STZ injection.Methods Sixty KM mice were randomly divided into 4 groups(n=15), two control groups and two model groups.In the two control groups, one was blank control and the other was negative control.Mice in the blank control group treated with no injection, but mice in the negative control group were treated with injection of citric acid salt buffer.For the two model groups, one was single high-dose group, 150 mg/kg STZ was injected only once.The other was multiple low-dose group, 50 mg/kg STZ was injected for 5 consecutive days.After the last injection, daily food and water intake were tested, blood glucose level and body weight were examined once a week for 4 consecutive weeks. Results Mice in the two model groups showed typical features of diabetes.The blood glucose levels in the two model groups were significantly higher than in the two control groups ( P <0.05 ) .For the two model groups, the molded rate of 150 mg/kg and 50 mg/kg group were 60% and 53.33%respectively at 1st week, but at the 4th week, they were 60% and 80% respectively.The mortality of these two groups at the 4th week was 33.33% and 20% respectively.Moreover, the blood glucose level in multiple low-dose group increased stably from the 2nd week to the 4th week.Conclusion The multiple low-dose STZ injection (50 mg/kg for 5 consecutive days) is an optimal method for producing KM mice model of type 1 diabetes mellitus.

Up-regulation of Hsp72 and keratin16 mediates wound healing in streptozotocin diabetic rats

BACKGROUND: Impaired wound healing is a complication of diabetes and a serious problem in clinical practice. We previously found that whey protein (WP) was able to regulate wound healing normally in streptozotocin (STZ)-dia-betic models. This subsequent study was designed to assess the effect of WP on heat shock protein-72 (Hsp72) and keratin16 (Krt16) expression during wound healing in diabetic rats. METHODS: WP at a dosage of 100 mg/kg of body weight was orally administered daily to wounded normal and STZ-diabetic rats for 8 days. RESULTS: At day 4, the WP-treated diabetic wound was significantly reduced compared to that in the corresponding control. Diabetic wounded rats developed severe inflammatory infiltration and moderate capillary dilatation and regeneration. Treated rats had mild necrotic formation, moderate infiltration, moderate to severe capillary dilatation and regeneration, in addition to moderate epidermal formation. Hsp72 and Krt16 densities showed low and dense activity in diabetic wounded and diabetic wounded treated groups, respectively. At day 8, WP-treatment of diabetic wounded animals revealed great amelioration with complete recovery and closure of the wound. Reactivity of Hsp72 and Krt16 was reversed, showing dense and low, or medium and low, activity in the diabetic wounded and diabetic wounded treated groups, respectively. Hsp72 expression in the pancreas was found to show dense reactivity with WP-treated diabetic wound rats. CONCLUSION: This data provides evidence for the potential impact of WP in the up-regulation of Hsp72 and Krt16 in T1D, resulting in an improved wound healing process in diabetic models.

Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats.

Background: Glucova Active Tablet is a proprietary Ayurvedic formulation with ingredients reported for anti-hyperglycemic, anti-hyperlipidemic activity and antioxidant properties. Objective: Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats. Materials and Methods: Experimental Type I diabetes was induced in 24 albino rats with intra-peritoneal injection of streptozotocin (50 mg/kg). Type II diabetes was induced in 18 albino rats by intra-peritoneal injection of streptozotocin (35 mg/kg) al ong with high fat diet. The rats were divided in 5 groups for Type I model and 4 groups for Type II model. Normal control group was kept common for both experimental models. Glucova Active Tablet (108 mg/kg) treatment was provided for 28 days twice daily orally. Fasting blood glucose level, serum lipid profi le and liver anti-oxidant parameters like superoxide dismutase and reduced glutathione was carried out in both experimental models. Pancreas histopathology was also done. Statistical analysis were done by 'analysis of variance' test followed by post hoc Tukey’s test, with signifi cant level of P < 0.05. Results and Discussion: Glucova Active Tablet showed signifi cant effect on fasting blood glucose level. It also showed signifi cant alteration in lipid profi le and antioxidant parameters. Histopathology study revealed restoration of beta cells in pancreas in Glucova Active Tablet treated group. Conclusion: Finding of this study concludes that Glucova Active Tablet has shown promising anti-diabetic activity in Type I and Type II diabetic rats. It was also found showing good anti-hyperlipidemic activity and anti-oxidant property.

Screening for anti-diabetic effective fraction in leaves of Olea europaea / 中草药

Objective: To screen the anti-diabetic effective fraction in the leaves of Olea europaea. Methods: Different fractions (Frs. A-F) were prepared using reflux extraction and separation with macroporous resins. α-Amylase system, non-enzymatic glycation system, and alloxan-induced diabetic models of mice were used to evaluate the anti-diabetic activities of the different fractions, respectively. Results: Frs. C-F fractions showed the significant inhibitory activities against α-amylase system and non-enzymatic glycation system. Especially, fraction D showed the best anti-diabetic activity compared with the other fractions, which also displayed a good dose-effect relationship. The anti-diabetic activities of Frs. C and D were both obvious and Fr. D showed more significance. Conclusion: The leaves of O. europaea show the potential anti-diabetic activity and the most effective fraction is ascribed to Fr. D.

Influence of Rhubarb on Renal Expression of Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1 in Diabetes Mellitus Rats / 国际中医中药杂志

Objective To explore the influence of DaHuang on renal expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in diabetes mellitus rats. Methods After the DM rat model was made, 24 DM rats were selected randomly and divided into a model group (12 DM rats) and a Rhubarb group group were given pure water in equal amount every day. 8 weeks later, kidney was cut to make pathological slice and method of SP immunohistochemistry was adopted for staining. Observed the expression of ICAM-1 and VCAM-1. Result The renal expression of ICAM-1 and VCAM-1 in the rhubarb group and the model group were obviously increased compared with the normal group (P<0.05). The renal expression of ICAM-1 and VCAM-1 in the rhubarb group was obviously weaker than the normal group(P<0.05). Conclusion Rhubarb could obviously inhibit the renal expression of ICAM-1 and VCAM-1 in diabetes mellitus rats and protect kidney of diabetes mellitus rats.

Experimental study of the hypoglycemic activity of cortex moutan polysaccharide-2b / 中国临床药理学与治疗学

AIM: To study the hypoglycemic action of cortex moutan polysaccharide 2b (CMP 2b) and the its mechanism. METHODS: Some animal models in this study included the glucose induced hyperglycemic model in mice, the alloxan induced diabetic model in mice and rats, and the HCSS induced insulin resistance model in mice. Those models were used to investigate the effects of CMP 2b on blood glucose of normal and hyperglycemic model animals, on serum superoxide dismutase (SOD), serum insulin, glycated hemoglobin (GHb), and apolipoproteinA 1 (ApoA 1) in alloxan diabetic animals. RESULTS: CMP 2b significantly lowered the blood glucose in hyperglycemic mice and rats induced by glucose and alloxan. CMP 2b also raised the SOD and ApoA 1 level, decreased the GHb level in diabetic animals, and improved insulin resistance in mice. CONCLUSION: CMP 2b can control experimental hyperglycemia. Its mechanism is related to improving insulin sensitivity and enhancing the utilization of glucose in peripheral tissues.

Effect of the Time-choosing Administration of Spleen-reinforcing Therapy on the Blood Glucose Level and Circadian Rhythm in Experimental Diabetic Mice / 中医杂志

0.05).The two-week administration of Jianpi Recipe decreased the bloodglucose of diabetic mice.Normal saline had no obvious influence on it.Time-choosing recipe administration could adjust the circadian rhythm of bloodglucose concentration.Administration at 6am was more effective in adjusting bloodglucose rhythm.Conclusion Spleen-reinforcing therapy can decrease the bloodglucose of diabetic mice,and the effect tend to be more obvious with the administration prolonging.Administration at different time exerts different effect on circadian rhythm of bloodglucose concentrations.There exists different effect in different time administration in spleen-reinforcing therapy.