Inhibition of glycation and aldose reductase activity using dietary flavonoids: A lens organ culture studies

Naringenin, Hesperidin and Quercetin Ameliorate Radiation-Induced Damage In Rats: In Vivo And In Silico Evaluations

In this study, we sought to determine how well naringenin, hesperidin, and quercetin prevented damage brought on by radiotherapy. During the investigation, 48 adult female Sprague Dawley rats were used. Eight groups of eight rats each were formed by randomly assigning the rats to the groups. The normal control group was represented by Group 1. Group 2 rats were those that received a dose of 15 Gray (Gy) of radiotherapy. The rats assigned to Group 3 received only Naringenin, whereas those assigned to Group 4 received only quercetine, and those assigned to Group 5 received only hesperidin. Rats in Group 6, 7 and 8 were received naringenin, quarcetin and hesperidin at a dose of 50 mg/kg daily for one week prior to radiotheraphy exposition. After radiotheraphy and phenolic compounds rats were sacrificed and some metabolic enzyme (aldose reductase (AR), sorbitol dehydrogenase (SDH), paraoxonase-1 (PON1), butyrylcholinesterase (BChE) and glutathione S-transferase (GST)) activity was determined in eye and brain tissues. It was found that phenolic compounds have protective effect against radiation-induced damage because of their anti-diabetic antioxidant and anti-inflammatory properties. In addition, hesperidin was found to be superior to quercetin and naringenin in terms of enzyme activity efficacy. Furthermore, hesperidin exhibited favorable binding affinity for BChE in silico compared to other enzymes.

Discovering Potential Compounds for Venous Disease Treatment through Virtual Screening and Network Pharmacology Approach

Peripheral venous hypertension has emerged as a prominent characteristic of venous disease (VD). This disease causes lower limb edema due to impaired blood transport in the veins. The phlebotonic drugs in use showed moderate evidence for reducing edema slightly in the lower legs and little or no difference in the quality of life. To enhance the probability of favorable experimental results, a virtual screening procedure was employed to identify molecules with potential therapeutic activity in VD. Compounds obtained from multiple databases, namely AC Discovery, NuBBE, BIOFACQUIM, and InflamNat, were compared with reference compounds. The examination of structural similarity, targets, and signaling pathways in venous diseases allows for the identification of compounds with potential usefulness in VD. The computational tools employed were rcdk and chemminer from R-Studio and Cytoscape. An extended fingerprint analysis allowed us to obtain 1846 from 41,655 compounds compiled. Only 229 compounds showed pharmacological targets in the PubChem server, of which 84 molecules interacted with the VD network. Because of their descriptors and multi-target capacity, only 18 molecules of 84 were identified as potential candidates for experimental evaluation. We opted to evaluate the berberine compound because of its affordability, and extensive literature support. The experiment showed the proposed activity in an acute venous hypertension model.

Exploring inhibitory effect and mechanism of hesperetin-Cu (II) complex against protein glycation

Inhibition of advanced glycation end products (AGEs) formed in protein glycosylation is crucial for minimizing diabetic complications. Herein, the anti-glycation potential of hesperetin-Cu (II) complex was investigated. Hesperetin-Cu (II) complex strongly inhibited three stages glycosylation products in bovine serum albumin (BSA)-fructose model, especially for the inhibition of AGEs (88.45%), which was stronger than hesperetin (51.76%) and aminoguanidine (22.89%). Meanwhile, hesperetin-Cu (II) complex decreased the levels of BSA carbonylation and oxidation products. 182.50 µg/mL of hesperetin-Cu (II) complex inhibited 66.71% β-crosslinking structures of BSA, and scavenged 59.80% superoxide anions and 79.76% hydroxyl radicals. Moreover, after incubating with methylglyoxal for 24 h, hesperetin-Cu (II) complex removed 85.70% methylglyoxal. The mechanisms of protein antiglycation by hesperetin-Cu (II) complex may be through protecting structure, trapping methylglyoxal, scavenging free radicals and interacting with BSA. This study may contribute to the development of hesperetin-Cu (II) complex as a functional food additive against protein glycation.

Molecular docking and inhibition studies of vulpinic, carnosic and usnic acids on polyol pathway enzymes

Aldose reductase (AR) and sorbitol dehydrogenase (SDH) are important enzymes of the polyol pathway. In the current study, inhibitory effects of vulpinic acid (VA) carnosic acid (CA) and usnic acid (UA) on purified AR and SDH enzymes were determined. These enzymes inhibition could be essential to prevent diabetic complications. AR and SDH enzymes were purified from sheep kidney. Then, VA, CA and UA were tested in various concentrations against these enzymes activity in vitro. K_I values were found to be as 1.46 ± 0.04, 5.13 ± 0.25 and 11.71 ± 0.27 μΜ for VA, CA and UA, respectively, for AR. K_I constants were found to be as 15.32 ± 0.34, 145.60 ± 2.17 and 213.40 ± 2.64 μΜ VA, CA and UA, respectively, for SDH. These findings indicate that VA, CA and UA could be useful in the treatment of diabetic complications.Communicated by Ramaswamy H. Sarma.

N-substituted phthalazine sulfonamide derivatives as non-classical aldose reductase inhibitors

Aldose reductase (AR, AKR1B1; EC 1.1.1.21) is an aldo-keto reductase that has been widely investigated as an enzyme crucially involved in the pathogenesis of several chronic complications, including nephropathy, neuropathy, retinopathy, and cataracts associated with diabetes mellitus. Although sulfonamides have been reported to possess many other biological activities, in continuation of our interest in designing and discovering potent inhibitors of AR, herein, we have evaluated the AR inhibitory potential of N-substituted phthalazine sulfonamide derivatives 5a-l. The biological studies revealed that all the derivatives show excellent activity against AR, with K_I constants ranging from 67.73 to 495.20 nM. Among these agents, 4-(6-nitro-1,4-dioxo-1,2,3,4-tetrahydrophthalazine-2-carbonyl)benzenesulfonamide (5e) and 1,4-dioxo-3-(4-sulfamoylbenzoyl)-1,2,3,4-tetrahydrophthalazine-6-carboxylic acid (5f) showed prominent inhibitory activity with K_I values of 67.73 and 148.20 nM, respectively, vs AR and were found to be more potent than epalrestat (K_I  = 852.50 nM), the only AR inhibitor currently used in the therapy. Moreover, molecular docking studies were also performed to rationalize binding site interactions of these sulfonamides (5a-l) with the target enzyme AR. According to ADME-Tox, predicts were also determined that these derivatives be ARIs displaying suitable drug-like properties. The sulfonamides identified in this study may be used to develop lead therapeutic agents inhibiting diabetic complications.

Screening inhibitory effects of selected flavonoids on human recombinant aldose reductase enzyme: in vitro and in silico study

Aldose reductase (AR) is the first enzyme of the polyol pathway that has physiological importance under hyperglycaemic conditions. The article has been focussed on AR enzyme inhibition by selected compounds. For this purpose, the in vitro inhibitory effects of various compounds on commercially available recombinant human AR (rAR) enzyme activity were investigated. The IC₅₀ values of compounds on rAR inhibition effect were found for 6-hydroxy flavone, syringic acid, diosmetin, 6-fluoroflavone, 7-hydroxy-4'-nitroisoflavone, myricetin as 2.05, 2.97, 15.75, 16.1, 49.5, and 63 µM, respectively. 6-Hydroxy flavone and syringic acid competitively inhibited rAR with respect to the NADPH with K_i values 0.509 ± 0.036 and 0.842 ± 0.012 µM. In addition, docking studies were performed to evaluate the potential enzyme binding positions of the compounds. Our in vitro and in silico results indicated that the 6-hydroxy flavone may be a good lead compound in the development of AR inhibitors to prevent diabetic complications.

Hesperetin, a Promising Treatment Option for Diabetes and Related Complications: A Literature Review

The morbidity and mortality of diabetes have increased dramatically in recent decades. Novel strategies for treating diabetes and its complications with minimal side effects are in urgent need. New monomeric molecules extracted from herbal medicine, which is a form of alternative medicine, are being sought as drug candidates for the treatment of diabetes and its complications. Hesperetin (Hst), a citrus flavonoid, is of increasing interest in scientific studies recently due to its properties in combating diabetes and its complications, whereas existing studies are scattered and unsystematic. Here, we summarized the literature studies over the last 10 years to review the potential therapeutic role of Hst in the prevention and mitigation of diabetes and its complications, intending to provide promising strategies for the clinical management of diabetes and its complications.

Silymarin from Milk Thistle Fruits Counteracts Selected Pathological Changes in the Lenses of Type 1 Diabetic Rats

Diabetes is a metabolic disease affecting many tissues and organs. The main etiological factor for diabetic complications is hyperglycemia and subsequent pathologies, such as oxidative stress. One of the organs susceptible to the development of diabetic complications is the eye with all of its elements, including the lens. The aim of this study was to evaluate the effect of silymarin, an extract obtained from milk thistle fruit husks, on the oxidative stress markers in the lenses of type 1 diabetic rats. The study was performed on male rats in which type 1 diabetes was induced with 60 mg/kg streptozotocin injection. Diabetic animals were treated via an intragastric tube with silymarin at 50 and 100 mg/kg doses for four weeks. Multiple oxidative stress and polyol pathway-related parameters were measured in the lenses, and auxiliary biochemical tests in the serum were conducted. Diabetes induced severe pathological changes both in the lenses and the serum, and silymarin counteracted several of them. Nevertheless, the qualitative analyses encompassing all tested parameters indicate that silymarin slightly improved the overall state of diabetic animals. Upon the obtained results, it can be concluded that silymarin reveals a faint positive effect on the lenses in type 1 diabetic rats.

Physiological and Pathological Roles of Aldose Reductase

Aldose reductase (AR) is an aldo-keto reductase that catalyzes the first step in the polyol pathway which converts glucose to sorbitol. Under normal glucose homeostasis the pathway represents a minor route of glucose metabolism that operates in parallel with glycolysis. However, during hyperglycemia the flux of glucose via the polyol pathway increases significantly, leading to excessive formation of sorbitol. The polyol pathway-driven accumulation of osmotically active sorbitol has been implicated in the development of secondary diabetic complications such as retinopathy, nephropathy, and neuropathy. Based on the notion that inhibition of AR could prevent these complications a range of AR inhibitors have been developed and tested; however, their clinical efficacy has been found to be marginal at best. Moreover, recent work has shown that AR participates in the detoxification of aldehydes that are derived from lipid peroxidation and their glutathione conjugates. Although in some contexts this antioxidant function of AR helps protect against tissue injury and dysfunction, the metabolic transformation of the glutathione conjugates of lipid peroxidation-derived aldehydes could also lead to the generation of reactive metabolites that can stimulate mitogenic or inflammatory signaling events. Thus, inhibition of AR could have both salutary and injurious outcomes. Nevertheless, accumulating evidence suggests that inhibition of AR could modify the effects of cardiovascular disease, asthma, neuropathy, sepsis, and cancer; therefore, additional work is required to selectively target AR inhibitors to specific disease states. Despite past challenges, we opine that a more gainful consideration of therapeutic modulation of AR activity awaits clearer identification of the specific role(s) of the AR enzyme in health and disease.

Inhibitory Potential of Murraya Koenigii (L.) and Ficus Carica L. Extracts Against Aldose Reductase (ALR), Advanced Glycation End Products (AGEs) Formation and Sorbitol Accumulation

Introduction: Murraya koenigii (L.) and Ficus carica L. are traditionally used plants with significant medicinal and nutritional values. Aim and Objective: The present study was focused on the evaluation of hydro-alcoholic and aqueous extracts of M. koenigii (L.) leaves [MKHA (M. koenigii (L.) hydro-alcoholic extract) and MKAQ (M. koenigii (L.) aqueous extract)] and dried fruits of F. carica L. [FCHA (F. carica L. hydro-alcoholic extract) and FCAQ (F. carica L. aqueous extract)] in the attenuation of markers of microvascular complications associated with diabetes mellitus which can be further used to investigate the pharmacological activity of these plants in treatment of diabetes and its complications. Material and Method: The attenuating effect of the extracts was evaluated by calculating the ALR1 enzyme inhibition in a kidney of Wistar rat, anti-glycation activity in bovine serum albumin (BSA) and erythrocyte sorbitol accumulation inhibition in heparinized human blood. Results: A significant inhibitory effect (IC50 6.47μg/ml,7.26μg/ml,8.93 μg/ml and 9.66μg/ml) was observed with different concentrations of extracts (MKHA, MKAQ, FCHA and FCAQ) respectively, against ALR enzyme. After the 4th week of incubation, the inhibition of AGEs formation by MKHA, MKAQ, FCHA and FCAQ (500μg/ml) was found to be 82.58%, 78.58%, 74.39% and 69.56% respectively. MKHA, MKAQ, FCHA and FCAQ were found to exhibit significant inhibition against the accumulation of sorbitol in RBCs with IC50 188.88 μg/ml, 247.74μg/ml, 291.94μg/ml and 345.34μg/ml, respectively. Conclusion: The administration of different concentrations of MKHA, MKAQ, FCHA and FCAQ significantly attenuated ALR, AGEs and sorbitol accumulation; hence, it can provide a basis for identification and development of new inhibitors of these biomarkers.

Fundamentals of Diabetic Cataractogenesis and Promising Ways of its Pharmacological Correction

Cataracts in diabetes mellitus lead to decreased visual function and blindness. Cataract surgery for diabetes mellitus has limitations and complications. The search for effective means of conservative cataract therapy continues. The review presents the analysis of data from scientific sources, mainly for 2015–2020 using Internet resources (PubMed, Web of Science, Medline, eLibrary.Ru, Cyberleninka). In the work, diabetic cataractogenesis is presented as a sum of interrelated pathobiochemical processes. The main ones are the polyol pathway of glucose conversion, non-enzymatic glycation and oxidative modification of lens proteins, which are enhanced in diabetes mellitus. The lens has a high protein content. The formation of high molecular weight protein aggregates is of particular importance for the appearance of light scattering zones and a decrease in lens transparency. This review presents data on anti-cataract compounds that affect post-translational crystallin modification, prevent osmotic and oxidative stress in the lens, and exhibit antiglycation properties. This information shows that the search for means of pharmacological correction of cataractogenesis should be carried out among compounds with antioxidant and antiglycation activity. 

Coriandrum sativum improve neuronal function via inhibition of oxidative/nitrosative stress and TNF-α in diabetic neuropathic rats

ETHNOPHRAMACOLOGICAL RELEVANCE

Coriandrum sativum L. is traditionally acknowledged for its use in inflammatory disorders, altered blood lipid levels, respiratory and digestive problems.

AIM OF THE STUDY

The present study investigates possible role of hydro-alcoholic extract of C. sativum (CHA) seeds in the attenuation of indices of diabetic peripheral neuropathy (DPN).

MATERIALS AND METHODS

Phytochemical analysis was carried out by employing chromatographic, spectroscopic as well as spectrometric techniques. Diabetes was induced by a single i.p. injection of freshly prepared STZ (65 mg/kg). The indexed markers of DPN, i.e., thermal and mechanical hyperalgesia were found to be prominent on the 60th day of STZ administration. Administration of CHA (100, 200, and 400 mg/kg, p.o.) for 30 days was started on the substantiation of DPN onset. Molecular docking study was performed by targeting TNF-α.

RESULTS

Phytochemical analysis revealed the presence of flavonoids, terpenoids, and phenolic acids. Oral administration of CHA considerably attenuated hyperglycemia and decreased pain threshold in diabetic rats as well as modulated oxidative-nitrosative stress. Docking study suggested good affinity of flavonoids when docked into the binding site of TNF-α.

CONCLUSION

In conclusion, using STZ model, it was successfully predicted that CHA might be beneficial in diabetes-induced neuropathic pain by inhibiting oxidative/nitrosative stress and inflammatory cytokine.

Esculetin and idebenone ameliorate galactose-induced cataract in a rat model

Cataract is the principal cause of blindness. The enzyme, aldose reductase (AR) is a key player in polyol pathway. Buildup of polyols and oxidative stress are the main causes of cataractogenesis. This study investigated the cytoprotective properties of esculetin and idebenone in galactose-induced cataract. Rats were partitioned into four groups each of ten rats. Control group was fed with normal diet; group 2 rats were fed with galactose diet (50%); groups 3, 4 rats were fed with galactose diet concurrently with either esculetin (50 mg/kg BW) or idebenone (100 mg/kg BW), for 20 days. The study revealed that esculetin and idebenone significantly reduced the elevated levels of Bax/Bcl-2 ratio, malondialdehyde, and DNA fragmentation and increased total antioxidant capacity level in lenses compared to the cataract-induced group. Only esculetin decreased AR, galactitol, and advanced glycated end products levels in lenses. Histopathological examinations supported the biochemical findings. Esculetin and idebenone may have chemopreventive effects for sugar cataract. PRACTICAL APPLICATIONS: Cataract is an age-related disease that might cause blindness in older adult people. Presently, no absolute pharmacological treatment is accessible for cataract. The use of natural products or their derivatives attract particular attention in modern medicines as they are believed to be safer with few or no side effects. Esculetin is a polyphenolic compound found in many medicinal plants. Idebenone is a synthetic analogue of coenzyme Q10. The current study is an approach to explore the anticataract effects of esculetin and idebenone in galactose-induced cataract in rats. Our study proved that both agents have anticataractogenic potentials due to their antioxidant and antiapoptotic properties.

Anti-glycation effect and the α-amylase, lipase, and α-glycosidase inhibition properties of a polyphenolic fraction derived from citrus wastes

The advanced glycation end products (AGEs) constitute a wide variety of substances synthesized from interactions between amino groups of proteins and reducing sugars, which excess induces pathogenesis of chronic diseases. Brazil is the major producer of citrus, a low-cost source of hesperidin, which is a polyphenol recognized for its capacity to inhibit AGEs formation. This is the first work to evaluate the effects of a polyphenolic fraction derived from citrus wastes on the antiglycation and on the inhibition properties of digestive enzymes on the possibility to process these wastes in high value-added products. At concentrations of 10, 15 and 20 mg/mL inhibition of AGEs was higher than 60%. The extracts were able to inhibit by 76% the activity of pancreatic lipase and by 98% the activity of α-glucosidase. For the α-amylase the inhibition capacity was lower than 50%. Strong correlation was obtained among anti-glycation with polyphenolic content and antioxidant capacity.

FlavoDb: a web-based chemical repository of flavonoid compounds

There are many online resources that focus on chemical diversity of natural compounds, but only handful of resources exist that focus solely on flavonoid compounds and integrate structural and functional properties; however, extensive collated flavonoid literature is still unavailable to scientific community. Here we present an open access database 'FlavoDb' that is focused on providing physicochemical properties as well as topological descriptors that can be effectively implemented in deducing large scale quantitative structure property models of flavonoid compounds. In the current version of database, we present data on 1, 19,400 flavonoid compounds, thereby covering most of the known structural space of flavonoid class of compounds. Moreover, effective structure searching tool presented here is expected to provide an interactive and easy-to-use tool for obtaining flavonoid-based literature and allied information. Data from FlavoDb can be freely accessed via its intuitive graphical user interface made available at following web address: http://bioinfo.net.in/flavodb/home.html.

Inhibition effects of quinones on aldose reductase: Antidiabetic properties

Diabetes mellitus is a chronic metabolic disease characterized by abnormal glucose metabolism. Aldose reductase (AR) is the first enzyme in the polyol pathway and converts glucose to sorbitol. It plays a vital role as a glucose reducing agent and is involved in the pathophysiology of diabetic complications. In this study, we purified AR from sheep kidney with a specific activity of 2.00 EU/mg protein and 133.33- fold purification After the purification of the AR enzyme, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed and the molecular weight of the enzyme was found approximately as 38 kDa. The inhibition effects of eight quinones were studied against AR. The quinones were potent inhibitors of AR with K_i values in the range of 0.07-20.04 μM. Anthraquinone showed the best potential inhibitory effects against AR. All compounds exhibited noncompetitive inhibition against AR. These compounds may be selective inhibitors of this enzyme. AR inhibition is an essential strategy for the attenuation and prevention of diabetic complications.

Exploring African Medicinal Plants for Potential Anti-Diabetic Compounds with the DIA-DB Inverse Virtual Screening Web Server

Medicinal plants containing complex mixtures of several compounds with various potential beneficial biological effects are attractive treatment interventions for a complex multi-faceted disease like diabetes. In this study, compounds identified from African medicinal plants were evaluated for their potential anti-diabetic activity. A total of 867 compounds identified from over 300 medicinal plants were screened in silico with the DIA-DB web server (http://bio-hpc.eu/software/dia-db/) against 17 known anti-diabetic drug targets. Four hundred and thirty compounds were identified as potential inhibitors, with 184 plants being identified as the sources of these compounds. The plants Argemone ochroleuca, Clivia miniata, Crinum bulbispermum, Danais fragans, Dioscorea dregeana, Dodonaea angustifolia, Eucomis autumnalis, Gnidia kraussiana, Melianthus comosus, Mondia whitei, Pelargonium sidoides, Typha capensis, Vinca minor, Voacanga africana, and Xysmalobium undulatum were identified as new sources rich in compounds with a potential anti-diabetic activity. The major targets identified for the natural compounds were aldose reductase, hydroxysteroid 11-beta dehydrogenase 1, dipeptidyl peptidase 4, and peroxisome proliferator-activated receptor delta. More than 30% of the compounds had five or more potential targets. A hierarchical clustering analysis coupled with a maximum common substructure analysis revealed the importance of the flavonoid backbone for predicting potential activity against aldose reductase and hydroxysteroid 11-beta dehydrogenase 1. Filtering with physiochemical and the absorption, distribution, metabolism, excretion and toxicity (ADMET) descriptors identified 28 compounds with favorable ADMET properties. The six compounds—crotofoline A, erythraline, henningsiine, nauclefidine, vinburnine, and voaphylline—were identified as novel potential multi-targeted anti-diabetic compounds, with favorable ADMET properties for further drug development.

3D-QSARs and molecular dynamics simulation studies on induced fit binding of flavones to human aldose reductase

Communicated by Ramaswamy H. Sarma.

Dietary flavonoids inhibit the glycation of lens proteins: implications in the management of diabetic cataract

The intervention of functional foods as complementary therapeutic approach for the amelioration of diabetes and sugar induced cataractogenesis is more appreciated over the present day chemotherapy agents owing to their nontoxic and increased bioavailability concerns. Dietary flavonoids, a class of bioactive phytochemicals is known to have wide range of biological activities against variety of human ailments. In the present study, we demonstrate anti-cataract effect of eight dietary flavonoids in sugar induced lens organ culture study. We present data on processes like inhibition of glycation-induced lens cloudiness, lens protein aggregation, glycation reaction and advanced glycation end products formation that can act as biochemical markers for this disease. The selected flavonoids were also tested for their aldose reductase (AR) inhibition (experimental and in silico). The molecular dynamics simulation results shed light on mechanistic details of flavonoid induced AR inhibition. The outcome of the present study clearly focuses the significance of kaempferol, taxifolin and quercetin as potential candidates for controlling diabetic cataract.

Antioxidative effect of flavonoid naringenin in the lenses of type 1 diabetic rats

Oxidative stress arising during diabetes may lead to cataract formation. Thus, in order to prevent oxidative stress development, antioxidants could be considered helpful agents. Naringenin, a flavonoid with a well-documented antioxidative activity, can be found in many plant-derived products, especially citrus fruits. The aim of the study was to examine the effect of naringenin on oxidative stress markers in the lenses of type 1 diabetic rats. The study was conducted on 3-month-old male Wistar rats with streptozotocin-induced type 1 diabetes. The rats were treated orally with naringenin at the doses of 50 and 100 mg/kg for 4 weeks. In the lenses obtained from the animals, enzymatic and non-enzymatic parameters connected with oxidative stress were measured. The enzymatic parameters included superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase activity. For non-enzymatic parameters, the total thiol groups, reduced and oxidized glutathione, protein carbonyl groups, advanced oxidation protein products, malondialdehyde and vitamin C level were assayed. Oral administration of naringenin counteracted most of the unfavorable changes induced by diabetes, including reduction of elevated antioxidative enzymes activity and amelioration of oxidative damage in proteins and lipids. Naringenin administered orally reduces oxidative stress markers in the lenses of type 1 diabetic rats.

An allied approach for in vitro modulation of aldose reductase, sorbitol accumulation and advanced glycation end products by flavonoid rich extract of Coriandrum sativum L. seeds

Traditional herbal medicines are attaining more popularity and are being widely practiced. Coriandrum sativum L. is one of the oldest herbal medicinal plants valued for its nutritional and medicinal properties. Present investigation was focussed on evaluation of attenuating potential of flavonoid rich extract of C. sativum (FCS) seeds against pathogenic markers of diabetic complications i.e. advanced glycation end products (AGEs), sorbitol and aldose reductase (ALR); by using in-vitro methods. Gas chromatography-mass spectrometry (GC-MS) and Infrared spectroscopy of FCS revealed the presence of different flavonoids. Results demonstrated that FCS has produced 79.80% inhibition of AGEs formation. Additionally, FCS was effective against sorbitol accumulation and ALR inhibition with IC₅₀ values of 221 μg/ml and 6.08 μg/ml respectively. Molecular docking was conducted against three binding site for ALR, RAGEs and sorbitol dehydrogenase to explore their binding interactions with identified flavonoids. The constituents F₂, F₄ and F₆ have shown good binding interactions with all the receptors. The visualisation of the docked complexes revealed the occurrence of hydrophobic forces and hydrogen bonding in receptor and docked constituents. The results were in support with experimental inhibitory activities of FCS against these biomarkers and provide a considerable basis for the identification and development of new inhibitors.

Cyanidin-3-O-glucoside functions like chemical chaperone and attenuates the glycation mediated amyloid formation in albumin

In this study, chemical chaperone like function of cyanidin-3-O-glucoside (C3G) was investigated through fluorescence spectroscopy, UV-visible spectroscopy, circular dichroism spectroscopy, confocal microscopy, scanning electron microscopy and molecular docking studies. Early and advanced glycation inhibitory effect was evaluated by fluorescence spectroscopy and agarose gel electrophoresis. Amyloids were investigated based on their propensity to bind Congo Red (CR) and Thioflavin T (ThT) by multiple microscopic approaches. Circular dichroism studies were used to analyze the changes in the secondary structure due to glycation. C3G effectively inhibited early and advanced glycation by masking like function, carbonyl scavenging and chemical chaperone activity. C3G had molecular interaction with Glu186, Arg427, Ser428, Lys431, Arg435, and Arg458 of BSA. Based on the microscopic analysis, it is evident that C3G can inhibit protein aggregation and amyloid formation. Circular dichroism studies suggested that glycation had resulted in augmented β-sheet propensity, whereas C3G had a protective effect on the helical conformation of BSA. We conclude that C3G has a chemical chaperone like function on the event of glycation mediated amyloid formation in BSA.

Flavonoids as detoxifying and pro-survival agents: What's new?

The role of flavonoids in the survival machinery of cells has come in the spotlight due to the recent evidence of their effect on the relationship mitochondria-ER stress-proteasome, including the intracellular mechanisms of autophagy and apoptosis. Numerous experimental animal investigations and even human clinical studies have highlighted the major role of these natural compounds in the economy of life and their deep relationship with autotrophic organisms in the evolutionary space. Their role as anti-oxidant and oxidative stress preventive molecules has to date been investigated extensively in the literature. Despite this great amount of promising evidence, many concerns, however, remain, most of which dealing with biochemistry, bioavailability, pharmacokinetics, and interaction of flavonoids with gut microbiome, issues that make difficult any good attempt to introduce these molecules in the human healthcare systems as possible, encouraging therapeutic substances. This review tries to address and elucidate these items.