Identifying the stability of housekeeping genes to be used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diabetic rats

AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.

Protective effect of liraglutide on the myocardium of type 2 diabetic rats by inhibiting polyadenosine diphosphate-ribose polymerase-1

BACKGROUND In recent years,studies have found that the occurrence and development of diabetic cardiomyopathy(DCM)is closely related to an increase in polyadenosine diphosphate-ribose polymerase-1(PARP-1)activity.PARP-1 activation could be involved in the pathophysiological process of DCM by promoting oxidative stress,the inflammatory response,apoptosis and myocardial fibrosis.AIM To investigate the mechanism of liraglutide in improving myocardial injury in type 2 diabetic rats,further clarified the protective effect of liraglutide on the heart,and provided a new option for the treatment of DCM.METHODS Forty healthy male SD rats aged 6 wk were randomly divided into two groups,a normal control group(n=10)and a model group(n=30),which were fed an ordinary diet and a high-sugar and high-fat diet,respectively.After successful modeling,the rats in the model group were fed a high-glucose and high-fat diet for 4 wk and randomly divided into a model group and an intervention group(further divided into a high-dose group and a low-dose group).The rats were fed a high-glucose and high-fat diet for 8 wk and then started drug intervention.Blood samples were collected from the abdominal aorta to detect fasting blood glucose and lipid profiles.Intact heart tissue was dissected,and its weight was used to calculate the heart weight index.Haematoxylin and eosin staining was used to observe the pathological changes in the myocardium and the expression of PARP-1 in the heart by immunohistochemistry.RESULTS The body weight and heart weight index of rats in the model group were significantly increased compared with those in the normal control group,and those in the intervention group were decreased compared with those in the model group,with a more obvious decrease observed in the high-dose group(P<0.05).In the model group,myocardial fibers were disordered,and inflammatory cells and interstitial fibrosis were observed.The cardiomyopathy of rats in the intervention group was improved to different degrees,the myocardial fibers were arranged neatly,and the myocardial cells were clearly striated;the improvement was more obvious in the high-dose group.Compared with the normal control group,the expression of PARP-1 in myocardial tissue of the model group was increased,and the difference was statistically significant(P<0.05).After liraglutide intervention,compared with the model group,the expression of PARP-1 in myocardial tissue was decreased,and the reduction was more obvious in the high-dose group(P<0.05)but still higher than that in the normal control group.CONCLUSION Liraglutide may improve myocardial injury in type 2 diabetic rats by inhibiting the expression of myocardial PARP-1 in a dose-dependent manner.

Effect of angiotensin Ⅱ type 1 receptor blocker and angiotensin converting enzyme inhibitor on the intraocular growth factors and their receptors in streptozotocin-induced diabetic rats

AIM： To investigate the effect of angiotensin II type 1 receptor blocker （ARB） and angiotensin converting enzyme inhibitor （ACEI） on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS： Forty Sprague-Dawley rats were divided into 4 groups： control, diabetes mellitus （DM）, candesartan- treated DM, and enalapril-treated DM （each group, n---10）. After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/（kg · d）] and enalapril [ACEI, 10 mg/（kg · d）] were administered to rats orally for 4Wko Vascular endothelial growth factor （VEGF） and angiotensin II （Ang II） concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor （ATIR） levels were assessed at week 4 by Western blotting. RESULTS： Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control （P=0.04 and 0.005, respectively）. Vitreous ATIR increased significantly in DM compared to the other three groups （P〈0.007）. Candesartan-treated DM rats showed higher vitreal ATIR concentration than the enalapril-treated DM group and control （P〈0.001 and P=0.005, respectively）. No difference in vitreous Ang II and ATIR concentration was found between the enalapril- treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION： Increased Ang II and ATIR in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.

Histopathological changes in retinas and F-ERG features of streptozotocin-induced diabetic rats treated with ozone

AIM： To study the histopathological changes in the retina and flash electroretinogram （F-ERG） features of ozone-treated streptozotocin （STZ）-induced diabetic rats. METHODS： Seventy male Sprague Dawley rats were grouped as follows： blank group （GB, n=10）, model control group （GM, n=18）, ozone group （GOs, n=19）, and oxygen group （GO2, n=18）. The model was induced by single intraperitoneal injection of STZ. Ozone or oxygen enteroclysm was given twice per week for 4wk. F-ERG and histopathological examinations were performed one month after treatment. RESULTS： Under dark adaption, as compared to GB, the other groups each had differential decreases in the a-wave amplitudes （P〈0.05）; the latencies were delayed in GM, GO2, and GO3 rats （P〈0.05）. Similar results were observed under light adaption, with the exception that the a-wave of the amplitudes （F=0.28, P〉0.05）. There were significant differences in the apoptosis index among the groups （P〈0.05）. Under ozone treatment, apoptosis was decreased in GO3 as compared to GM and GO2 . CONCLUSION： Ozone administration alleviates nerve damage and reduces pathology and apoptosis in the retinas of diabetic rats.

N-acetylcysteine attenuates ischemia/reperfusion-induced cardiocyte apoptosis in diabetic rats

Objective：To study the effects of N-acetylcysteine （NAC） on ischemia/ reperfusion （I/R）-induced myocyte apoptosis in diabetic rats. Methods：The I/R heart model was made by ligation of the left anterior descending coronary artery （LAD） close to its origin. The LAD was occluded for 30 min followed by removal of ligation to allow subsequent reperfusion for 3 h. 72 rats were randomly divided into two groups , non-diabetic group （C, n = 36） and diabetic group ,（D, n = 36）. The animals in C group were randomly reassigned into sham-operated group （CS, n = 12） , I/R group （C I/R, n = 12） and treated with NAC group （CN, n = 12）. The rats in D group were also reassigned to sham-operated group （DS, n = 12） , I/R group （DI/R, n = 12） and treated with NAC group （DN, n = 12）. Malondialdehyde （MDA） and creatine kinase isoenzyme-MB （CK-MB） were measured. Infarct size（IS/AAR%）, the apoptosis index（AI） by TUNEL staining, the number of the cells positive for Caspase-3 and positive expression index （PEI） were calculated. Results：After I/R, the IS/AAR%, CK-MB, MDA, AI and Caspase-3 PEI were higher in diabetic group than those in non-diabetic group. Treatment with NAC decreased the above parameters in both non-diabetic and diabetic rats, but the parameters in diabetic rats were higher than those in non-diabetic rats. Conclusion：Diabetic rat hearts are more susceptible to I/R-induced myocardial necrosis and myocyte apoptosis. NAC can decrease the infarct size and attenuate cardiomyocyte apoptosis in both non-diabetic and diabetic rats, but the therapeutic effects are less effective in diabetic rats than those in non-diabetic rats.

Changes in 5α-reductase (type 2) gene expression in epididymis of puberty diabetic rats

The changes in 5α-reductase (type 2 ) gene expression in the epi-didymis of puberty diabetic rats were studied by the Northern blot and Dotblot method. Rats were divided into 3 groups: the control group (C), thediabetic group (D), and the diabetic group with insulin treatment (DI).Results: The Northern blot intensity of the caput epididymis in Group D is

Phenotypic Modulation of Mesangial Cells in Diabetic Rats and Effect of Tujian Mixture (菟箭合剂) on It

Objective: To explore whether there is phenotypic modulation of mesangial cells in streptozotocin (STZ) induced diabetic rats and study the effect of Tujian Mixture (TJM) on it. Methods: SD rats were divided into the normal control group , the unilateral nephrectomized control group , the STZ induced diabetes mellitus with unilateral nephrectomy model group , the Valsartan treated group (VT group, n=8) and the TJM treated group , rats in the latter two groups were modeled as in the DM group and treated with Valsartan (20 mg/kg·d) and TJM (20g/kg·d) respectively for 12 weeks. The expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β 1 (TGF-β 1) in rats’ glomeruli were observed by immunohistochemistry assay, and the ratio of α-SMA and TGF-β 1 positive area/total glomerule tuft area (SMA/GT and TGF/GT) were analyzed using computer-assisted image analysis software. Results: In the NC and the QC groups, only trace of α-SMA positive staining was found. But there was prominant α-SMA positive staining in glomeruli of the DM group, with SMA/GT and TGF/GT increased significantly , and marked increase of 24 hrs proteinuria excretion ( P<0 01). As compared with the DM group, the three indexes were all significantly lower in the VT and ZY groups , and the lowering of proteinuria was more significant in the ZY group than that in the VT group (P<0 01). Conclusion: The expression of α-SMA in glomeruli in STZ induced diabetic rats with unilateral nephrectomy is pronounced, indicating that phenotypic modulation of mesangial cells involvement in the pathogenesis of diabetic nephropathy. TJM and Valsartan can reduce 24 hrs proteinuria excretion, inhibit the phenotypic modulation of mesangial cells and the expression of TGF-β 1 in glomeruli of diabetic rats, and the effect of TJM is more potent than that of Valsartan in lowering urinary protein excretion..

1,25-Dihydroxyvitamin D_(3) effects on the regulation of the insulin receptor gene in the hind limb muscle and heart of streptozotocin-induced diabetic rats

In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.

Antidiabetic and Anti-oxidative Effects of Honokiol on Diabetic Rats Induced by High-fat Diet and Streptozotocin

Objective To study the antidiabetic and anti-oxidative effects of honokiol （Hon） in Magnolia officinalis and its underlying molecular mechanism in diabetic rats induced by high-fat diet （HFD） and streptozotocin （STZ）. Methods After ig administration with Hon [25, 50, and 100 mg/（kg.d）] to diabetic rats for consecutive 10 weeks, the levels of blood glucose （BG）, oral glucose tolerance （OGT）, blood lipids including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesterol （LDL-C）, hepatic oxidative stress including the activities of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px）, methane dicarboxylic aldehyde （MDA）, and cytochrome P4502E1 （CYP2E1） in diabetic rats were measured. Results Compared to the diabetic control rats, ig administration of Hon resulted in significant decrease in BC, TC, TG, and LDL-C levels in serum, as well as hepatic CYP2E] activity and MDA content in diabetic rats, whereas the level of OGT and activities of hepatic CAT, SOD, and CSH-Px in diabetic rats were significantly increased. Conclusion Hon could alleviate hyperglycemia, hyperlipemia, hepatic oxidative damage, and insulin resistance in diabetic rats by inhibiting hepatic CYP2E1 activity.

Hypoglycemic and Hypolipidemic Effects of Lycium barbarum Polysaccharide in Diabetic Rats

Objective To study the antidiabetic effects and the underlying molecular mechanisms of Lycium barbarum polysaccharide（LBP） and its DEAE cellulose elution fraction LBP-IV in diabetic rats induced by high fat diet（HFD） and streptozotocin（STZ）. Methods After ig administration of LBP-IV [50, 100, and 200 mg/（kg·d）] and LBP [100 mg/（kg·d）] once daily for consecutive 4 weeks to diabetic rats, the glucose and lipids in blood, m RNA expression of phosphoenolpyruvate carboxykinase（PEPCK）, sterol regulatory element binding-protein-1c（SREBP-1c）, and fatty acid synthase（FAS） in liver were determined. Results Ig administration of LBP and LBP-IV significantly decreased the levels of blood glucose, Hb A1 c, TC, TG, and LDL-C, as well as the hepatic m RNA expression of PEPCK, SREBP-1c, and FAS, whereas significantly increased the oral glucose tolerance of diabetic rats. Conclusion The findings suggest that the antidiabetic effects of LBP and LBP-IV are associated with the decreased hepatic m RNA expression of PEPCK, SREBP-1c, and FAS in HFD-STZ induced diabetic rats.

Protective effect of LIF-huM SCs on the retina of diabetic model rats

AIM:To investigate the protective effect of human umbilical cord mesenchymal stem cells(hUCMSCs)modified by the LIF gene on the retinal function of diabetic model rats and preliminarily explore the possible mechanism.METHODS:A stably transfected cell line of hUCMSCs overexpressing leukemia inhibitory factor(LIF)was constructed.Overexpression was verified by fluorescent quantitative polymerase chain reaction(qPCR).Forty-eight adult Sprague-Dawley rats were randomly divided into a normal control group(group A),streptozotocin-induced diabetic control group(group B),diabetic rats at 3mo injected with empty vector-transfected hUCMSCs(group C)or injected with LIF-hUCMSCs(group D).Four weeks after the intravitreal injection,analyses in all groups included retinal function using flash electroretinogram(F-ERG),retinal blood vessel examination of retinal flat mounts perfused with fluorescein isothiocyanate-dextran(FITCdextran),and retinal structure examination of sections using hematoxylin and eosin staining.Expression levels of adiponectin(APN),high-sensitivity C-reactive protein(hsCRP),and neurotrophin-4(NT-4)in each group was detected using immunohistochemistry,PCR,Western blotting,and ELISA,respectively.RESULTS:A stable transgenic cell line of LIF-hUCMSCs was constructed.F-ERG and FITC-dextran examinations revealed no abnormalities of retinal structure and function in group A,severe damage of the retinal blood vessels and function in group B,and improved retinal structure and function in group C and especially group D.qPCR,ELISA,and Western blot analyses revealed progressively higher APN and NT-4 expression levels in groups B,C,and D than in group A.hs-CRP expression was significantly higher in group B than in groups A,C,and D,and was significantly higher in group C than in group D(P<0.05).CONCLUSION:LIF-hUCMSCs protect the retina of diabetic rats by upregulating APN and NT-4 expression and downregulating hs-CRP expression in the retina.

Comparative Study on Effects of Different Treatments in Preventing Myocardial Ischemia Caused by Coronary Artery Ligation in Diabetic Rats

Objective: To compare the preventive effect of treatment with different methods of traditional Chinese medicine(TCM) for myocardial ischemia caused by coronary artery ligation in diabetic rats. Methods: Animal models established by streptozotocin plus coronary artery ligation were treated by modified Taoren Chengqi Deconcton (MTRCQD) and different combinations of its imgreddints respectively , and the dffects on is chemia area , occurrence of arrhbthmia.T-wave in ECG and 2 hrs post-operational survival rate were observed and compared . Results :MTRCQD and differdnt combinations of its ingredients could reduce the area of is chemia and elevate survival rate significantly (P<0.05-0.01), especiclly in the group treated with MTRCQD plus leech .Conclusion:TCM treatment of invigorating QI nourshing Yin ,purging Heat and activating blood circulation is an deeective treatment for diabetic coronaty heart disease.

Effects of gliclazide on myocardial protection of isolated type 2 diabetic rat heart afforded by ischemic preconditioning

The myocardial protection afforded by ischernic preconditioning （IPC） can alleviate ischemi- a-repel-fusion injury in normal rat heart. However, this myocardial protection is seldom studied in the type 2 diabetic rat with myocardial ischemia disease. In this study, we aimed to evaluate the effects of ATP-sensitive potassium channels （KATP channels） on IPC in the isolated type 2 diabetic rat heart and the role of the sul- fonylurea gliclazide. Methods Streptozotocin（STZ）-induced type 2 diabetic male Wistar rats with or without gliclazide （64 mg/kg body weight, orally） and age-matched non-diabetic control rats were used for all studies. The isolated hearts were perfused with Langendorff＇s system under the constant flow, pressure and tempera- ture conditions with Kreb＇s-Henseleit solution （K-H）. After 5 minutes of balance peffusion, these rats were randomly divided into six groups： non-diabetic control rats without IPC （CIR） ; non-diabetic control rats with IPC （CIP）; diabetic rats without 1PC （DIR）; diabetic rats with IPC （DIP）; gliclazide-treated diabetic rats without IPC （GIR）; and gliclazide-treated diabetic rats with IPC （GIP）. Groups CIR, DIR, and GIR were subjected to 30-rain global ischemia and 60-rain reperfusion for induction of ischemia/reperfusion injury. Groups CIP, DIP, and GIP were given three cycles of 5-min ischemia and 5-rain reperfusion as IPC, and then ischemia/reperfusion injury program was implemented. Extent of ischemia/reperfusion injury was measured in terms of the release of lactate dehydrogenase （LDH）, creatine kinase （CK）, and creatin kinase-MB （CK- MB） in coronary effluent. After perfusion, Kir6.2 and SUR2A mRNA expressions in the myocardial tissue were characterized by fluorescent quantitative real-time PCR method, and Kir6.2 and SUR2A protein expres- sions were assessed by immunohistochemistry. Result In non-diabetic control rats, the release of LDH, CK, and CK-MB in coronary effluent markedly decreased with IPC compared with No-IPC （P 〈 0.05）, but not in diabetic rats. However, in gliclazide-treated diabetic rats, IPC-induced decrease in the release of LDH, CK, and CK-MB was restored compared with No-IPC （P 〈 0.05）. The expressions of Kir6.2 both at mRNA and protein levels in CIP were significantly higher than those in CIR. There was no significant difference in theexpression of Kir6.2 and SUR2A both at mRNA and protein levels between DIP and DIR. However, the expression of Kir6.2 both at mRNA and protein levels was significantly higher in GIP than in GIR. No significant difference was detected in the mRNA expression level of SUR2A between the six groups. The expression of SUR2A at protein level was significantly higher in CIP than in CIR and in GIP than in GIR. Conclusions The cardioprotective effect of IPC is abolished in the isolated type 2 diabetic rats compared with non-diabetic control rats. However, to some extent, gliclazide can improve the myocardial protection of IPC against ischemia/reperfusion injury, thus suggesting that it is mediated mainly by KATP channels at mRNA or protein level, which provides a basis for further investigating the effects of KATP channels on IPC.

Modulation of fasting blood glucose by raw banana powder in alloxan-induced diabetic rats

This study aimed to observe the influence of raw banana powder(RBP)on fasting blood glucose(FBG),blood lipid and other biochemical indicators in type-2 diabetic rats and therefore to provide experimental evidences for developing suitable food from banana powder for diabetic patients.Eight Sprague-Dawley rats were selected randomly as the normal control group(NCG)before the experiment.After establishing type-2 diabetic rat models(11.1-16.7 mmoL/L)by alloxan,32 rats were divided into four groups:the diabetic control group(DCG,n=8),low-dose group(LDG,n=8),middle-dose group(MDG,n=8)and high-dose group(HDG,n=8).The LDG,MDG and HDG rats received gastric perfusion of RBP at the doses of 2 g/kg,4 g/kg and 6 g/kg per day,respectively.After four weeks,oral glucose tolerance test was carried out in each group,and then the FBG level,blood lipid,insulin,short chain fatty acids content,pH value of colon content and other biochemical indicators of rats in each group were determined and compared among the groups.Results showed that the levels of FBG significantly decreased in the LDG(11.97±0.83),MDG(8.95±0.45)and HDG(9.28±1.45),compared with their initial values(13.00±1.25,13.68±0.75 and 13.91±0.80,respectively).The FBG levels in these three groups were obviously lower than that in the DCG.However,there were no dramatic FBG changes in the NCG and DCG(5.77±0.59,14.14±0.72)compared with the initial stage(5.55±0.23,13.93±0.47).The RBP intervention increased insulin-sensitivity index and regulated postprandial blood glucose.Besides,RBP showed the positive effects on symptoms of type 2 diabetic rats,such as the reduction of weight gain and total cholesterol.

Biomechanics of Bone in Experimental Diabetic rats.

The biomechanics of bone In diabetics and its response to insulin treatment was not clear.We investigated the impace of alloxan-induced diabetes and insulin treatment on the biomechanical characteristics of bones．Sprague-Dawley rats were divided into three groups:

Role of Wnt signaling pathway hypofunction mediated by dephosphorylation of β-catenin in impaired wound healing of type 1 diabetic rats

Objective To investigate the role of Wnt signaling pathway hypofunction mediated by dephosphorylation ofβ-catenin in the impaired wound healing of type 1 diabetic rats.Methods The back skin defect wounds were produced in rats with type 1 diabetes.These rats were divided into control,diabetes,lithium chloride treatment,and epidermal growth factor(EGF)

Danhong Huayu Koufuye combined with metformin attenuated diabetic retinopathy in Zucker diabetic fatty rats

AIM: To evaluate effects of Danhong Huayu Koufuye (DHK, a Chinese medicinal formulae) alone or combined with metformin on diabetic retinopathy (DR) in Zucker diabetic fatty (ZDF) rats, an animal model of obese type -2 diabetes, and then to investigate the mechanisms. METHODS: ZDF (fa/fa) rats were administered with vehicle (distilled water), metformin, DHK, and DHK plus metformin. Electrophysiological and histological analysis were applied to evaluated effects of DHK alone or combined with metformin on DR. The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in blood were measured to evaluate the antihyperglycemic activity of DHK. Furthermore, levels of nitric oxide (NO), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured to study effects of DHK on oxidative stress in ZDF rats. In addition, body weight, lipidic indexes and insulin level were also assessed. RESULTS: DHK combined with metformin significantly reversed the prolongation of latency times of flash electroretinogram (FERG) and oscillatory potentials (OPs) in diabetic rats. Furthermore, DHK alone or combined with metformin showed a remarkable suppression of retinal neovascularization and amelioration of retinal internal limiting membrane morphology. Moreover, DHK alone or plus metformin reduced FBG (P<0.05), HbA1c 1094 (P<0.01) and MDA (P<0.01) levels in diabetic rats. In addition, reductions in levels of triglycerides (TG) (P<0.01) and low density lipoprotein cholesterol (LDL-c) (P<0.01 and P<0.05, respectively) were also observed in diabetic rats treated with DHK alone or plus metformin. CONCLUSION: DHK in combination with metformin had a preventive and therapeutic effect on DR in type-2 diabetic rats, and the possible mechanisms may be alleviating hyperglycemia, reducing oxidative stress and improving lipid metabolism.

Anti-diabetic Activity of Zhenqing Recipe and Ligustri Lucidi Fructus in Type 2 Diabetic Rats

Objective To investigate the influence of Zhenqing Recipe(ZQR)and Ligustri Lucidi Fructus(LLF)on diabetic rats and its possible mechanism.Methods The model of type 2 diabetic rats was established by feeding a high-sucrose-high-fat diet and injecting a low dose of Streptozotocin in Wistar rats.The model rats were randomly divided into three groups:diabetic model,ZQR-treated,and LLF-treated groups for 8-weeks treatment.The normal Wistar rats were as a normal control group.Results The level of fasting blood glucose in ZQR and LLF groups was decreased compared with model group(P<0.01,0.05,respectively).Both ZQR and LLF markedly reduced serum triglycerides(P<0.01,0.05,respectively),and increased the insulin sensitivity index(P<0.05).Histopathology revealed that ZQR and LLF reduced pancreatic damage.Immunohistochemistry evaluation showed that the percentage of insulin positive cells in pancreatic island was higher than model group(P<0.01,0.05,respectively).The mRNA and protein expression of SREBP-1c in pancreas were significantly decreased in ZQR and FLL group(P<0.01).Conclusion ZQR has therapeutic effect on type 2 diabetes,it ameliorates the histopathological changes of pancreas,protectsβcells,improves insulin resistance,and attenuates the expression of SREBP-1c.This study also provides the anti-diabetic evidence of FLL even its effects are weaker than ZQR.

Controlled-release neurotensin-loaded silk fibroin dressings improve wound healing in diabetic rat model

Diabetic foot ulcers(DFU),which may lead to lower extremity amputation,is one of the severe and chronic complications of diabetic mellitus.This study aims to develop,and use dressings based on Silk fibroin(SF)as the scaffold material,gelatin microspheres(GMs)as the carrier for the neurotensin(NT),a neuropeptide that acts as an inflammatory modulator in wound healing and NT as accelerate wound healing drug to treat DFU.We evaluated the wound healing processes and neo-tissue formation in rat diabetic model by macroscopic observation,histological observation(H&E staining and Masson's trichrome staining)and immunofluorescence analysis at 3,7,14,21 and 28 post-operation days.Our results show that the NT/GMs/SF group performance the best not only in macroscopic healing and less scars in 28 post-operation days,but also in fibroblast accumulation in tissue granulation,collagen expression and deposition at the wound site.From release profiles,we can know the GMs are a good carrier for control release drugs.The SEM results shows that the NT/GMs/SF dressings have an average pore size are 40–80μm and a porosity of∼85%,this pore size is suit for wound healing regeneration.These results suggest that the NT/GMs/SF dressings may work as an effective support for control release NT to promote DFU wound healing.