Astragalin attenuates diabetic cataracts via inhibiting aldose reductase activity in rats

AIM:To investigate the aldose reductase(AR)inhibition capacity of astragalin(AST)against streptozoticin-induced diabetic cataracts(DCs)in rats.METHODS:Ex vivo investigations were conducted by treating the lens of a goat placed for 72h in artificial aqueous humor(AAH)of pH 7.8 at room temperature with cataract-causing substance(55 mmol/L of galactose)and in vivo studies were performed on rats via induction with streptozotocin.AST was administered at different dose levels and scrutinize for DC activity.RESULTS:In diabetic rats,AST improved the body weight,blood insulin,and glucose as well as the levels of galactitol in a dose-dependent way,other biochemical parameters i.e.inflammatory mediators and cytokines,and also suppress AR activity.The level of the antioxidant parameters such as superoxide dismutase(SOD),catalase(CAT),and glutathione(GSH)activity were also altered on a diabetic lens after the administration of the AST.CONCLUSION:AST protects against lens opacification to avoid cataracts and polyols formation,indicating that it could be used as a potential therapeutic agent for diabetes.

Association of C(-106)T Polymorphism in Aldose Reductase Gene with Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes Mellitus

Objective To identify the possible association between C（-106）T polymorphism of the aldose reductase （ALR） gene and diabetic retinopathy （DR） in a cohort of Chinese patients with type 2 diabetes mellitus （T2DM）. Methods From November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy （DWR） group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C（-106）T polymorphism （rs759853） in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed. Results A total of 268 T2DM patients （129 in the DR group and 139 in the DWR group） were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset （P=0.10） and gender （P=0.78）. The success rate of genotyping for the study subjects was 99.6% （267/268）, with one case of failure in the DR group. The frequencies of the T allele in the C（-106）T polymorphism were 16.0% （41/256） in the DR group and 19.4% （54/278） in the DWR group （P=0.36）. There was no signit^cant difference in the C（-106）T genotypes between the 2 groups （P=0.40）. Compared with the wild-type genotype, odds ratio （OR） for the risk of DR was 0.7 （95% CI, 0.38-1.3） for the heterozygous CT genotype and 0.76 （95% CI, 0.18-3.25） for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria （OR=4.61; 95% CI, 2.34-9.05） and insulin therapy （OR=3.43; 95% CI, 1.94-6.09）. Conclusions Microalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C（-106）T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.

Diallyl sulfide protects against N-nitrosodiethylamine-induced liver tumorigenesis:Role of aldose reductase

AIM: To evaluate the protective effect of diallyl sulfide (DAS) against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis.METHODS: Male Wistar rats received either NDEA or NDEA together with DAS as protection.Liver energy metabolism was assessed in terms of lactate,pyruvate,lactate/pyruvate,ATP levels,lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PD) activities.In addition,membrane disintegration of the liver cells was evaluated by measuring lipid-peroxidation products,measured as malondialdehyde (MDA); nitric oxide (NO) levels; glucose-6-phosphatase (G6Pase),catalase (CAT) and superoxide dismutase (SOD) activities.Liver DNA level,glutathione-S-transferase (GST) and cytochrome c oxidase activities were used as DNA fragmentation indices.Aldose reductase (AR) activity was measured as an index for cancer cells resistant to chemotherapy and histopathological examination was performed on liver sections from different groups.RESULTS: NDEA significantly disturbed liver functions and most of the aforementioned indices.Treatment with DAS significantly restored liver functions and hepatocellular integrity; improved parameters of energy metabolism and suppressed free-radical generation.CONCLUSION: We provide evidence that DAS exerts a protective role on liver functions and tissue integrity in face of enhanced tumorigenesis caused by NDEA,as well as improving cancer-cell sensitivity to chemotherapy.This is mediated through combating oxidative stress of free radicals,improving the energy metabolic state of the cell,and enhancing the activity of G6Pase,GST and AR enzymes.

Repression of Polyol Pathway Activity by Hemidesmus indicus var.pubescens R.Br.Linn Root Extract,an Aldose Reductase Inhibitor:An In Silico and Ex Vivo Study

Development of diabetic cataract is mainly associated with the accumulation of sorbitol via the polyol pathway through the action of Aldose reductase(AR).Hence,AR inhibitors are considered as potential agents in the management of diabetic cataract.This study explored the AR inhibition potential of Hemidesmus indicus var.pubescens root extract by in silico and ex vivo methods.Molecular docking studies(Auto Dock tool)betweenβ-sitosterol,hemidesminine,hemidesmin-1,hemidesmin-2,and AR showed thatβ-sitosterol(−10.2 kcal/mol)and hemidesmin-2(−8.07 kcal/mol)had the strongest affinity to AR enzyme.Ex vivo studies were performed by incubating isolated goat lenses in artificial aqueous humor using galactose(55 mM)as cataract inducing agent at room temperature(pH 7.8)for 72 h.After treatment with Vitamin E acetate−100μg/mL(standard)and test extract(500 and 1000μg/mL)separately,the estimation of biochemical markers showed inhibition of lens AR activity and decreased sorbitol levels.Additionally,extract also normalized the levels of antioxidant markers like SOD,CAT,GSH.Our results showed evidence that H.indicus var.pubescens root was able to prevent cataract by prevention of opacification and formation of polyols that underlines its potential as a possible therapeutic agent against diabetic complications.

INHIBITION OF RAT LENS ALDOSE REDUCTASE BY QUERCETAGETIN AND PATULETIN

In this paper the results of inhibition of the Aldose reductase(AR) activity on Wistar rat lens by Quercetagetin extracted from Tagetes erects Linn and by Patuletin extracted from Tagetes patula Linn are reported.Quercetagetin inhibited AR of the rat lens by 93.9% at 10^(-4)M, 76.0% at 10^(-5)M and 13.3% at 10^(-6)M. Patuletin inhibited AR of the rat lens by 100% at 10^(-1)M, 80% at 10^(-5)M and 22.7% at 10^(-6)M respectively. The results show that these two flavones are lens AR Inhibitors, but further ...

Reducing host aldose reductase activity promotes neuronal differentiation of transplanted neural stem cells at spinal cord injury sites and facilitates locomotion recovery

Neural stem cell(NSC)transplantation is a promising strategy for replacing lost neurons following spinal cord injury.However,the survival and differentiation of transplanted NSCs is limited,possibly owing to the neurotoxic inflammatory microenvironment.Because of the important role of glucose metabolism in M1/M2 polarization of microglia/macrophages,we hypothesized that altering the phenotype of microglia/macrophages by regulating the activity of aldose reductase(AR),a key enzyme in the polyol pathway of glucose metabolism,would provide a more beneficial microenvironment for NSC survival and differentiation.Here,we reveal that inhibition of host AR promoted the polarization of microglia/macrophages toward the M2 phenotype in lesioned spinal cord injuries.M2 macrophages promoted the differentiation of NSCs into neurons in vitro.Transplantation of NSCs into injured spinal cords either deficient in AR or treated with the AR inhibitor sorbinil promoted the survival and neuronal differentiation of NSCs at the injured spinal cord site and contributed to locomotor functional recovery.Our findings suggest that inhibition of host AR activity is beneficial in enhancing the survival and neuronal differentiation of transplanted NSCs and shows potential as a treatment of spinal cord injury.

Search of inhibitors of aldose reductase for treatment of diabetic cataracts using machine learning

Purpose:Patients with diabetes mellitus have an elevated chance of developing cataracts,a degenerative visionimpairing condition often needing surgery.The process of the reduction of glucose to sorbitol in the lens of the human eye that causes cataracts is managed by the Aldose Reductase Enzyme(AR),and it is been found that AR inhibitors may mitigate the onset of diabetic cataracts.There exists a large pool of natural and synthetic AR inhibitors that can prevent diabetic complications,and the development of a machine-learning(ML)prediction model may bring new AR inhibitors with better characteristics into clinical use.Methods:Using known AR inhibitors and their chemical-physical descriptors we created the ML model for prediction of new AR inhibitors.The predicted inhibitors were tested by computational docking to the binding site of AR.Results:Using cross-validation in order to find the most accurate ML model,we ended with final cross-validation accuracy of 90%.Computational docking testing of the predicted inhibitors gave a high level of correlation between the ML prediction score and binding free energy.Conclusions:Currently known AR inhibitors are not used yet for patients for several reasons.We think that new predicted AR inhibitors have the potential to possess more favorable characteristics to be successfully implemented after clinical testing.Exploring new inhibitors can improve patient well-being and lower surgical complications all while decreasing long-term medical expenses.

Polymorphisms and functions of the aldose reductase gene 5' regulatory region in Chinese patients with type 2 diabetes mellitus

Objective To screen the 5’ regulatory region of the aldose reductase (AR) gene for genetic variabilities causing changes in protein expression and affecting the promoter function. Methods The screenings were carried out by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). All SSCP variants were submitted for DNA sequencing and inserted into the plasmid chloromycetin acetyl transferase (CAT) enhancer vector. The constructs were used to transfect Hela cells,and CAT assays were performed to assess promoter activity. Gel mobility shift and footprinting assays were also performed to determine the interaction between the DNA and nuclear proteins. Results Two polymorphisms, C(-106)T and C(-12)G, were identified in the regulatory region in 123 Chinese control subjects and 145 patients with type 2 diabetes mellitus. The frequencies of genotypes WT/WT, WT/C(-12)G and WT/C(-106)T were not significantly different between the subjects and patients. In the patients with and without retinopathy, frequencies of WT/C(-106)T were 31.5% and 17.5% (P【0.05) respectively, and the frequencies of WT/C(-12)G were 10.5% and 2.5% (P】0.05) respectively. The total frequency of WT/C(-12)G and WT/C(-106)T in patients with retinopathy was 41.8%, significantly higher than that (20.0%) in patients without retinopathy (P【0.025). The relative transcription activities of the wild-type, the C(-12)G and the C(-106)T were 15.7%, 31.0% and 32.2%, respectively. The results of DNA-protein interaction assays showed that these variations did not change the binding site of DNA with trans-acting factors. Conclusion The polymorphisms C(-12)G and C(-106)T strongly associated with diabetic retinopathy in the Chinese population have been identified in the regulatory region of the aldose reductase gene.

Berberine ameliorates renal injury in streptozotocin-induced diabetic rats by suppression of both oxidative stress and aldose reductase

Background Berberine is one of the main constituents of Coptidis rhizoma （CR） and Cortex phellodendri. In this study, we investigated the beneficial effects of berberine on renal function and its possible mechanisms in rats with diabetic nephropathy （DN）. Methods Male Wistar rats were divided into three groups： normal, diabetic model, and berberine treatment groups. Rats in the diabetic model and berberine treatment groups were induced to diabetes by intraperitonal injection with streptozotocin （STZ）. Glomerular area, glomerular volume, fasting blood glucose （FBG）, blood urea nitrogen （BUN）, serum creatinine （Cr） and urine protein for 24 hours （UP24h） were measured using commercially available kits. Meanwhile, the activity of superoxide dismutase （SOD）, content of malondialdehyde （MDA） in serum, activity of aldose reductase （AR） and the expression of AR mRNA and protein in kidney were detected by different methods. Results The results showed that oral administration of berberine （200 mg·kg^-1·d^-1） significantly ameliorated the ratio of kidney weight to body weight. Glomerular area, glomerular volume, FBG, BUN, Cr and UP24h were significantly decreased in the berberine treatment group compared with the diabetic model group （P〈0.05）. Berberine treatment significantly increased serum SOD activity and decreased the content of MDA compared with diabetic model group （P 〈0.05）. AR activity as well as the expression of AR mRNA and protein in the kidney was markedly decreased in the berberine treatment group compared with diabetic model group （P 〈0.05）. Conclusion These results suggested that berberine could ameliorate renal dysfunction in DN rats through controlling blood glucose, reduction of oxidative stress and inhibition of the activation of the polyol pathway.

Inhibitory effect of eleven herbal extracts on advanced glycation end-products formation and aldose reductase activity

The formation of advanced glycation end-products （AGEs） and aldose reductase （AR） activity have been implicated in the development of diabetic complications. Our study sought to characterize the capacities of eleven herbal extracts against the formation of AGEs and the AR activity. An ultrahigh performance liquid chromatography and tandem mass spectrometry （UPLC-MS/MS） method was used for the detection of AR activity and the screening of AR inhibitors in this research. The amount of sorbitol from each analyte was directly detected using the multiple reaction monitoring mode and the sorbitol level could be reduced via the addition of an inhibitor. Moreover, the BSA/glucose （fructose） system was applied to investigate their inhibitory activities of AGEs formation in glycation model reactions. Compared with other screened herbs used in our study, Flos Sophorae lrnrnaturus and Radix Scutellariae seemed to be more effective on inhibiting the formation of AGEs and AR activity. The inhibiting capacities of herbal extracts against AR activity and AGEs formation may be correlated with the bioactive components of the herbal extracts. The differences were correlated with the amount of polyphenol and flavonoid components. In the study, we have investigated the potential anti-hyperglycemic bioactivity of eleven herbal extracts in vitro, which could provide a reference for further in vivo research in the prevention and treatment of diabetic complications.

Pharmacologically tested aldose reductase inhibitors isolated from plant sources—A concise report

Aldose reductase (AR), a cytosolic, monomeric oxidoreductase, is a key enzyme in the polyol pathway which controls the conversion of glucose to sorbitol. The accumulation of sorbitol by the activation of AR enzymes in lens, retina, and sciatic nerves leads to the cause of diabetic defects resulting in various secondary complications, viz. retinopathy, neuropathy, nephropathy and Alzheimer's disease. Thus, reduction of the polyol pathway flux by AR inhibitors could be a potential therapeutic opening in the treatment and prevention of diabetic complications. At present, the AR inhibitors belong to two different chemical classes. One is the hydantoin derivatives, such as Sorbinil, Dilantin, and Minalrestat, and the other is the carboxylic acid derivatives, such as Epalrestat, Alrestatin, and Tolrestat. However, it is known that most of these synthethic compounds have unacceptable side-effects. Well known medicinal plants like Chrysanthemum indicum, Chrysanthemum morifolium, Prunus mume, Myrcia multiflora, Centella asiatica, and Salacia reticulata, Salacia oblonga, and Salacia chinensis exhibited potent AR inhibitory activity. The present review summarizes the list of plant material, and their isolated phytoconstituents which have been tested for their AR inhibitory activity. This litreature review covers the period to 2011, and a total of 72 plants are listed.

Effects of different anesthesiaes on activity of aldose reducetase inRBC and level of plasma nitric oxide in patients undergoing gastric canceroperation

Objective: To investigate the effects of different anesthesiaes on the activity of aldose reductase(AR) in RBC and the levels of plasma nitric oxide(NO) in patients undergoing gastric cancer operation. Methods: Twenty-eight patients undergoing gastric cancer operation were randomly divided into two groups with 14 cases for each. Anesthesia was maintained with 1.5-2.0MAC isoflurane plus epidural block in group Ⅱ. Venous blood samples were collected to measure the AR ctivity in RBC, the levels of plasma NO and glucose. Results: The plasma levels of glucose were increased significantly at 90 min after incision and kept at the high levels till the 1st postoperative day in group Ⅰ(P<0.01 or P<0.05) as compared with those before anesthesia, the changes in group Ⅱ were same as in group Ⅰ(P<0.01),but not on the 1st postoperative day. There was no significant difference between the two groups. The activity of AR in RBC was increased significantly and the level of plasma NO was decreased significantly on the 1st postoperative day in group Ⅰ(P<0.05). In group Ⅱ, AR and NO changed slightly,but these changes were not significant. The extent of change in the activity of AR or the level of NO no the 1st postoperative day in group Ⅱ was less than that in group Ⅰ(P<0.05). Conclusion: Polyol pathway in RBC activated under surgical hyperglycemia while the production of NO is inhibited in patients undergoing gastric cancer operation, which can be effectively attenuated by combined general-epidural anesthesia.

Epalrestat protects against diabetic peripheral neuropathy by alleviating oxidative stress and inhibiting polyol pathway

Epalrestat is a noncompetitive and reversible aldose reductase inhibitor used for the treatment of diabetic neuropathy. This study assumed that epalrestat had a protective effect on diabetic peripheral nerve injury by suppressing the expression of aldose reductase in peripheral nerves of diabetes mellitus rats. The high-fat and high-carbohydrate model rats were established by intraperitoneal injection of streptozotocin. Peripheral neuropathy occurred in these rats after sustaining high blood glucose for 8 weeks. At 12 weeks after streptozotocin injection, rats were intragastrically administered epalrestat 100 mg/kg daily for 6 weeks. Transmission electron microscope revealed that the injuries to myelinated nerve fibers, non-myelinated nerve fibers and Schwann cells of rat sciatic nerves had reduced compared to rats without epalrestat administuation. Western blot assay and immunohistochemical results demonstrated that after intervention with epalrestat, the activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase gradually increased, but aldose reductase protein expression gradually diminished. Results confirmed that epalrestat could protect against diabetic peripheral neuropathy by relieving oxidative stress and suppressing the polyol pathway.

Efficacy of epalrestat plus α-lipoic acid combination therapy versus monotherapy in patients with diabetic peripheral neuropathy: a meta-analysis of 20 randomized controlled trials

OBJECTIVE： To evaluate the efficacy of α-lipoic acid（ALA） plus epalrestat combination therapy in the treatment of diabetic peripheral neuropathy（DPN）. DATA SOURCES： The electronic databases of Pub Med, Medline, Embase, the Cochrane Library, the Chinese National Knowledge Infrastructure, the Wanfang Database and the Chinese Biomedical Database were used to retrieve relevant studies without language restrictions. The search was conducted from the inception of each database to 7 October 2016. The key terms were（diabetic peripheral neuropathy or diabetic neuropathy or DPN） AND（α-lipoic acid or lipoic acid or thioctic acid） AND epalrestat. DATA SELECTION： All of the eligible studies met the following inclusion criteria：（1） Randomized controlled trials that compared efficacy and safety of epalrestat plus ALA combination therapy versus epalrestat or ALA monotherapy in patients with DPN.（2） The minimum duration of treatment was 2 weeks.（3） The DPN patients were diagnosed using the World Health Organization standardized type 2 diabetes mellitus and DPN criteria.（4） Studies contained at least one measure that could reflect the efficacy of the drug and nerve conduction velocities. Studies in which the control group used epalrestat or ALA combined with other drugs were excluded. Statistical analyses were performed using STATA software for meta-analysis. OUTCOME MEASURES： The primary outcomes were the therapeutic efficacy, median motor nerve conduction velocity（MNCV）, median sensory nerve conduction velocity（SNCV）, peroneal MNCV and peroneal SNCV.RESULTS： Twenty studies with 1894 DPN patients were included, including 864 patients in the ALA plus epalrestat group, 473 in the ALA group and 557 in the epalrestat group. The efficacy of ALA plus epalrestat combination therapy was superior to ALA and epalrestat monotherapies（RR = 1.29, 95% CI： 1.21–1.38; RR = 1.43, 95% CI： 1.34–1.54, respectively）. ALA plus epalrestat combination therapy also significantly improved median MNCV（WMD = 5.41, 95% CI： 2.07–8.75）, median SNCV（WMD = 5.87, 95% CI： 1.52–10.22）, peroneal MNCV（WMD = 5.59, 95% CI： 2.70–8.47） and peroneal SNCV（WMD = 4.57, 95% CI： 2.46–6.68）.CONCLUSION： ALA plus epalrestat combination therapy was superior to ALA and epalrestat monotherapies for clinical efficacy and nerve conduction velocities in patients with DPN.

Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy

AIM: To study the contribution of tonicity response element binding protein(Ton EBP) in retinal ganglion cell(RGC) death of diabetic retinopathy(DR).METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin(STZ). Control mice received vehicle(phosphate-buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of Ton EBP and aldose reductase(AR) were examined.RESULTS: The Ton EBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase(Td T)-mediated d UTP nick end labeling(TUNEL)-positive signals co-localized with Ton EBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls.CONCLUSION: The present data show that AR and Ton EBP are upregulated in the DR and Ton EBP may contribute to apoptosis of RGC in the DR.

Synthesis and Antibacterial Activities of Selenide Derivatives of Benzisoselenazolone

A series of Benzisolselenazolone (BISA) derivatives were synthesized and evaluated for their antibacterial activities againstE coli. by using LKB-2277 bioactivity monitor. Other bioactivities were tested by the method of High Throughput Screening for pharmaceutical activity compounds (HTP) BISA derivatives 3b, at the concentration of 40 μg/mL, showed 100%antibacterial activity and 62%inhibition rate of aldose reductase (at the concentration of 5μg/mL). These new compound structures have determined by IR,1H NMR and MS spectra.

Comparisons of different methods of anesthesia and analgesia on the levels of glycometabolism rate-limiting enzymes in erythrocytes and plasma glucose and stress hormones in patients undergoing esophagus surgery

Objective： To compare the effects of different methods of anesthesia and analgesia on the activities of phosphofructokinase（PFK）, glucose-6-phosphate dehydrogenase（G-6PD） and aldose reductase（AR） in erythrocytes and levels of plasma glucose and stress hormones in patients undergoing esophagus surgery. Methods： Sixty-two patients scheduled for esophagus surgery were randomly divided into three groups： group Ⅰ （n = 20） receiving only general anesthesia（GA） followed by intravenous patient controlled analgesia（PCA） with fentanyl 15 μg/kg. The other two groups receiving both general anesthesia combined with thoracic epidural anesthesia （GEA） and either intravenous PCA with fentanyl 15 μg/kg （group Ⅱ, n = 21） or thoracic epidural analgesia（TEA） with 0.125% ropivacaine and 0.0002% fentanyl mixture（group Ⅲ, n = 21） after the operation. Venous blood samples were collected for measurements of PFK, G-rPD and AR activities in erythrocytes and plasma glucose, cortisol, epinephrine and norepinephrine before induction （T1）, 60 min following the incision （T2）, 60 min（T3） after operation, on the lst（T4） and 2nd postoperative day（T5）. Results： The activities of PFK decreased（P 〈 0.01 or P = 0.004） and the activities of G-6PD and AR increased（P 〈 0.01） in groups Ⅰ and Ⅱ on T4 compared with those on T1 Between the two groups, the activities of these enzymes in group Ⅱ changed less than those of group Ⅰ （P 〈 0.01 or P 〈 0.05）. These enzymes activities changed slightly in group Ⅲ on T4（P 〉 0.05）. There were significant differences between group Ⅲand the other two groups（P 〈 0.0l or P 〈 0.05）. The levels of plasma glucose increased significantly on T2（P 〈 0.01）, reached peak values on Ta（P 〈 0.01） and fell on T5 in the three groups. Compared to those of groups Ⅰ and Ⅱ, the values of plasma glucose in group Ⅲwere lower on T4 and T5（P 〈 0.05 or P 〈 0.01）. The cortisol concentration in each group increased significantly at T2（P 〈 0.01 or P 〈 0.05）, and remained elevated on T5（P 〈 0.01 or P 〈 0.05）, while on T2 and T3 the cortisol levels＇ of group I were higher than that of groups Ⅱand Ⅲ （P 〈 0.05）. The levels of group Ⅲ were lower than those of the other groups on T4 and T5（P 〈 0.01 or P 〈 0.05）. The levels of epinephrine and norepinephrine were also significantly higher in group Ⅰ than those of the other two groups on T2（P 〈 0.01 or P 〈 0.05）, and their levels in group Ⅰ and Ⅱ were higher than that of group Ⅲ on T4. The patients of the three groups obtained satisfactory pain relief, with all Vidual Analogue Scale（VAS） scores less than 3. VAS scores of group I were much greater 4h after operation. Group m VAS scores were the lowest 24h after operation. However, the number of times patients pressed the bolus switch was higher in group Ⅱ （P 〈 0.01）. Conclusion： Compared with GA and intravenous PCA, general anesthesia combined with thoracic epidural anesthesia and analgesia obtain better pain relief and could markedly alleviate the stress response and improve these erythrocyte glucose metabolism changes after esophagus surgery.

Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L. and Persea americana Mill.

Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana(P. americana)(traditionally used in Cameroon against diabetes) on β-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results:The tested extracts strongly inhibited β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from(1.07 ± 0.03) to(31.77 ± 1.17) μg/mL.Among the tested extracts, P. americana was the most active against sensitive enzymes(IC50 of1.07 ± 0.03 to 15.63 ± 1.23). But, none of the extracts showed interesting inhibitory effect against β-glucosidase as their percentage inhibitions were less than 16%. From gas chromatographymass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P.americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.

Virtual screening of flavonoids from Jatropha gossypiifolia L.as potential drugs for diabetic complications

Background:Diabetes mellitus is a chronic metabolic disease that is a risk factor for epidemic pathologies.Under hyperglycemic conditions,the enzyme aldose reductase catalyzes the formation of sorbitol in the metabolism of glucose via polyols,leading to the development of diabetic complications.Therefore,inhibitors of this enzyme are therapeutic targets for the prophylaxis and treatment of these conditions.Methods:In this study,a generalized linear regression model was developed to analyze flavonoids-obtained from a database-that have been tested as inhibitors of aldose reductase.In this sense,the molecular descriptors implemented in DRAGON and MATLAB software were used to determine the correlation between the chemical structure of the inhibitors and their pharmacological activity.The model was validated according to the Organisation for Economic Co-operation and Development Standards and subsequently used for the virtual screening of the flavonoids identified in Jatropha gossypiifolia L.Results:The proposed model showed a good fit for its statistical parameters(R2=0.95).In addition,it showed good predictive power(R2 ext=0.94)and robustness(Q2 LOO=0.92).The experimental chemical space wherein the predictions were reliable(domain of application)was also defined.Finally,the model was used to identify 10 flavonoids from Jatropha gossypiifolia L.as candidates for natural drugs.Compounds with a low probability of oral absorption were identified,among which the elagic acid biflavonoid showed the greatest promise(pIC50 predicted=9.75).Conclusion:The Jatropha gossypiifolia L.species harbors flavonoids with high potential as inhibitors of the aldose reductase enzyme,in which the biflavonoid ellagic acid was shown to be the most promising inhibitor of the aldose reductase enzyme,suggesting its possible use in the treatment of the late complications of diabetes mellitus.