scholarly journals Anti-diabetic activity of flavonoid rich fraction of Pedalium murex in the medicine: Biological importance of aldose reductase in polyol pathway for prevention of microvascular complications

Bone Reports ◽  
2021 ◽  
Vol 14 ◽  
pp. 100932
Author(s):  
Dinesh Kumar Patel
Keyword(s):  
Aldose Reductase ◽  
Microvascular Complications ◽  
Polyol Pathway ◽  
Biological Importance ◽  
Pedalium Murex

scholarly journals Aldose Reductase and the Polyol Pathway in Schwann Cells: Old and New Problems

2021 ◽  
Vol 22 (3) ◽  
pp. 1031
Author(s):  
Naoko Niimi ◽  
Hideji Yako ◽  
Shizuka Takaku ◽  
Sookja K. Chung ◽  
Kazunori Sango
Keyword(s):  
Schwann Cells ◽  
Aldose Reductase ◽  
Critical Role ◽  
Polyol Pathway ◽  
Glucose Flux ◽  
Rate Limiting ◽  
Deficient Mice ◽  
Excess Glucose ◽  
Shed Light ◽  
Immortalized Schwann Cells

Aldose reductase (AR) is a member of the reduced nicotinamide adenosine dinucleotide phosphate (NADPH)-dependent aldo-keto reductase superfamily. It is also the rate-limiting enzyme of the polyol pathway, catalyzing the conversion of glucose to sorbitol, which is subsequently converted to fructose by sorbitol dehydrogenase. AR is highly expressed by Schwann cells in the peripheral nervous system (PNS). The excess glucose flux through AR of the polyol pathway under hyperglycemic conditions has been suggested to play a critical role in the development and progression of diabetic peripheral neuropathy (DPN). Despite the intensive basic and clinical studies over the past four decades, the significance of AR over-activation as the pathogenic mechanism of DPN remains to be elucidated. Moreover, the expected efficacy of some AR inhibitors in patients with DPN has been unsatisfactory, which prompted us to further investigate and review the understanding of the physiological and pathological roles of AR in the PNS. Particularly, the investigation of AR and the polyol pathway using immortalized Schwann cells established from normal and AR-deficient mice could shed light on the causal relationship between the metabolic abnormalities of Schwann cells and discordance of axon-Schwann cell interplay in DPN, and led to the development of better therapeutic strategies against DPN.

scholarly journals Protective Pleiotropic Effect of Flavonoids on NAD+Levels in Endothelial Cells Exposed to High Glucose

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Daniëlle M. P. H. J. Boesten ◽  
Saskia N. I. von Ungern-Sternberg ◽  
Gertjan J. M. den Hartog ◽  
Aalt Bast
Keyword(s):  
Endothelial Cells ◽  
Enzyme Activity ◽  
Aldose Reductase ◽  
High Glucose ◽  
Umbilical Vein ◽  
Polyol Pathway ◽  
Pleiotropic Effect ◽  
Protective Role ◽  
Parp Activation

NAD+is important for oxidative metabolism by serving as an electron transporter. Hyperglycemia decreases NAD+levels by activation of the polyol pathway and by overactivation of poly(ADP-ribose)-polymerase (PARP). We examined the protective role of three structurally related flavonoids (rutin, quercetin, and flavone) during high glucose conditions in anin vitromodel using human umbilical vein endothelial cells (HUVECs). Additionally we assessed the ability of these flavonoids to inhibit aldose reductase enzyme activity. We have previously shown that flavonoids can inhibit PARP activation. Extending these studies, we here provide evidence that flavonoids are also able to protect endothelial cells against a high glucose induced decrease in NAD+. In addition, we established that flavonoids are able to inhibit aldose reductase, the key enzyme in the polyol pathway. We conclude that this protective effect of flavonoids on NAD+levels is a combination of the flavonoids ability to inhibit both PARP activation and aldose reductase enzyme activity. This study shows that flavonoids, by a combination of effects, maintain the redox state of the cell during hyperglycemia. This mode of action enables flavonoids to ameliorate diabetic complications.

scholarly journals Reverse Docking, Molecular Docking, Absorption, Distribution, and Toxicity Prediction of Artemisinin as an Anti-diabetic Candidate

Molekul ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 88
Author(s):  
Ruswanto Ruswanto ◽  
Richa Mardianingrum ◽  
Siswandono Siswandono ◽  
Dini Kesuma
Keyword(s):  
Molecular Docking ◽  
Aldose Reductase ◽  
Glucose Concentration ◽  
In Silico ◽  
Reductase Activity ◽  
Polyol Pathway ◽  
Toxicity Prediction ◽  
In Silico Studies

Aldose reductase is an enzyme that catalyzes one of the steps in the sorbitol (polyol) pathway that is responsible for fructose formation from glucose. In diabetes, aldose reductase activity increases as the glucose concentration increases. The purpose of this research was to identify and develop the use of artemisinin as an anti-diabetic candidate through in silico studies, including reverse docking, receptor analysis, molecular docking, drug scan, absorption, and distributions and toxicity prediction of artemisinin. Based on the results, we conclude that artemisinin can be used as an anti-diabetic candidate through inhibition of aldose reductase

scholarly journals Repurposing the aldose reductase inhibitor and diabetic neuropathy drug epalrestat for the congenital disorder of glycosylation PMM2-CDG

2019 ◽  
Author(s):  
Sangeetha Iyer ◽  
Feba S. Sam ◽  
Nina DiPrimio ◽  
Graeme Preston ◽  
Jan Verhejein ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Diabetic Neuropathy ◽  
Aldose Reductase ◽  
Reductase Inhibitor ◽  
Drug Repurposing ◽  
Polyol Pathway ◽  
Aldose Reductase Inhibitor ◽  
Congenital Disorder ◽  
Functional Studies ◽  
Congenital Disorder Of Glycosylation

AbstractPhosphomannomutase 2 deficiency, or PMM2-CDG, is the most common congenital disorder of glycosylation affecting over 1,000 patients globally. There are no approved drugs that treat the symptoms or root cause of PMM2-CDG. In order to identify clinically actionable compounds that boost human PMM2 enzyme function, we performed a multi-species drug repurposing screen using a first-ever worm model of PMM2-CDG followed by PMM2 enzyme functional studies in PMM2-CDG patient fibroblasts. Drug repurposing candidates from this study, and drug repurposing candidates from a previously published study using yeast models of PMM2-CDG, were tested for their effect on human PMM2 enzyme activity in PMM2-CDG fibroblasts. Of the 20 repurposing candidates discovered in the worm-based phenotypic screen, 12 are plant-based polyphenols. Insights from structure-activity relationships revealed epalrestat, the only antidiabetic aldose reductase inhibitor approved for use in humans, as a first-in-class PMM2 enzyme activator. Epalrestat increased PMM2 enzymatic activity in four PMM2-CDG patient fibroblast lines with genotypes R141H/F119L, R141H/E139K, R141H/N216I and R141H/F183S. PMM2 enzyme activity gains range from 30% to 400% over baseline depending on genotype. Pharmacological inhibition of aldose reductase by epalrestat may shunt glucose from the polyol pathway to glucose-1,6-bisphosphate, which is an endogenous stabilizer and coactivator of PMM2 homodimerization. Epalrestat is a safe, oral and brain penetrant drug that was approved 27 years ago in Japan to treat diabetic neuropathy in geriatric populations. We demonstrate that epalrestat is the first small molecule activator of PMM2 enzyme activity with the potential to treat peripheral neuropathy and correct the underlying enzyme deficiency in a majority of pediatric and adult PMM2-CDG patients.

scholarly journals Aldose Reductase Differential Inhibitors in Green Tea

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1003 ◽  
Author(s):  
Francesco Balestri ◽  
Giulio Poli ◽  
Carlotta Pineschi ◽  
Roberta Moschini ◽  
Mario Cappiello ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Green Tea ◽  
Aldose Reductase ◽  
Active Site ◽  
Inhibitory Action ◽  
Computational Study ◽  
Epigallocatechin Gallate ◽  
Polyol Pathway ◽  
Differential Inhibition ◽  
Tea Extract

Aldose reductase (AKR1B1), the first enzyme in the polyol pathway, is likely involved in the onset of diabetic complications. Differential inhibition of AKR1B1 has been proposed to counteract the damaging effects linked to the activity of the enzyme while preserving its detoxifying ability. Here, we show that epigallocatechin gallate (EGCG), one of the most representative catechins present in green tea, acts as a differential inhibitor of human recombinant AKR1B1. A kinetic analysis of EGCG, and of its components, gallic acid (GA) and epigallocatechin (EGC) as inhibitors of the reduction of L-idose, 4-hydroxy2,3-nonenal (HNE), and 3-glutathionyl l-4-dihydroxynonanal (GSHNE) revealed for the compounds a different model of inhibition toward the different substrates. While EGCG preferentially inhibited L-idose and GSHNE reduction with respect to HNE, gallic acid, which was still active in inhibiting the reduction of the sugar, was less active in inhibiting HNE and GSHNE reduction. EGC was found to be less efficient as an inhibitor of AKR1B1 and devoid of any differential inhibitory action. A computational study defined different interactive modes for the three substrates on the AKR1B1 active site and suggested a rationale for the observed differential inhibition. A chromatographic fractionation of an alcoholic green tea extract revealed that, besides EGCG and GA, other components may exhibit the differential inhibition of AKR1B1.

Sorbinil prevents glomerular hyperperfusion in diabetic rats

1989 ◽  
Vol 256 (6) ◽  
pp. F1000-F1006 ◽  
Author(s):  
N. Bank ◽  
P. Mower ◽  
H. S. Aynedjian ◽  
B. M. Wilkes ◽  
S. Silverman
Keyword(s):  
Aldose Reductase ◽  
Muscle Tone ◽  
Plasma Renin ◽  
Insulin Dependent Diabetes Mellitus ◽  
Polyol Pathway ◽  
Diabetic Rats ◽  
Dependent Diabetes Mellitus ◽  
Ang Ii ◽  
Receptor Sites ◽  
Single Nephron

The role of polyol pathway metabolism in glomerular hyperperfusion of insulin-dependent diabetes mellitus (IDDM) was studied in rats. Streptozotocin-induced diabetic rats were fed the aldose reductase inhibitor, sorbinil (8 mg/day). Untreated diabetic rats and normal rats served as controls. All groups were fed the same diet, rationed to 20 g/day. Micropuncture, plasma renin activity (PRA), and glomerular angiotensin II (ANG II)-receptor measurements were made 7-15 days after streptozotocin injection. Untreated diabetic rats had higher than normal single-nephron filtration rate (SNGFR), plasma flow (QA), and blood flow (SNBF), and reduced afferent resistance. Glomerular ANG II-receptor sites were markedly decreased. In diabetic rats fed sorbinil SNGFR, QA, and SNBF were all lower than in untreated diabetic rats, and indistinguishable from values in normal rats. However, single-nephron filtration fraction (SNFF) rose above normal. PRA, glomerular ANG II receptors, and blood glucose were not affected by sorbinil. In normal rats fed sorbinil, SNGFR, QA, and SNBF were not significantly different than in normal rats. Our observations are consistent with the view that polyol pathway metabolism plays a role in glomerular hyperperfusion in IDDM. Inhibition of aldose reductase increased vascular smooth muscle tone at pre- and probably postglomerular sites.

Electroretinogram in sucrose-fed diabetic rats treated with an aldose reductase inhibitor or an anticoagulant

1997 ◽  
Vol 273 (5) ◽  
pp. E965-E971 ◽  
Author(s):  
Nigishi Hotta ◽  
Jiro Nakamura ◽  
Fumihiko Sakakibara ◽  
Yoji Hamada ◽  
Tomohiro Hara ◽  
...  
Keyword(s):  
Animal Model ◽  
Diabetic Retinopathy ◽  
Aldose Reductase ◽  
Reductase Inhibitor ◽  
Polyol Pathway ◽  
Aldose Reductase Inhibitor ◽  
Dependent Diabetes Mellitus ◽  
Pathway Activity ◽  
Oletf Rats ◽  
Long Evans

To investigate the role of increased polyol pathway activity and hemodynamic deficits in the pathogenesis of diabetic retinopathy in non-insulin-dependent diabetes mellitus (NIDDM), Otsuka Long-Evans Tokushima fatty (OLETF) rats, an animal model of human NIDDM, were given water with or without 30% sucrose and some of them were fed laboratory chow containing 0.03% cilostazol, an anticoagulant, or 0.05% [5-(3-thienyl)tetrazol-1-yl] acetic acid monohydrate (TAT), an aldose reductase inhibitor, for 8 wk. Long-Evans Tokushima Otsuka (LETO) rats were used as nondiabetic controls. The peak latencies of oscillatory potentials of the electroretinogram in sucrose-fed OLETF rats were significantly prolonged compared with those in OLETF rats without sucrose feeding and LETO rats. There was a marked increase in platelet aggregability and a significant decrease in erythrocyte 2,3-diphosphoglycerate in sucrose-fed OLETF rats. Cilostazol significantly improved these parameters without changes in retinal levels of sorbitol and fructose. TAT, however, ameliorated all of these parameters. These findings confirm that the sucrose-fed OLETF rat is a useful animal model of retinopathy in human NIDDM and suggest that cilostazol improved diabetic retinopathy by modifying vascular factors, not by altering polyol pathway activity.

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