Antiglycation Potential Research Articles

Studies on the antiglycating potential of zinc oxide nanoparticle and its interaction with BSA

Nanoparticles have been proven to be a great tool as bio-sensors, medical therapeutic agents and drug delivery vehicles. In this study, the chemically synthesized zinc oxide nanoparticles (ZnO NPs) have been characterized with UV-spectrophotometer, FTIR, XRD, TEM and DLS. These ZnO NPs were investigated with respect to their binding interaction with serum albumin and the thermodynamic parameters of these interactions at different temperatures. Glycation process was checked in the presence of ZnO NPs by measuring fructosamine and carbonyl content for glycated end products and aggregation by Congo red assay. The intrinsic activities of bovine serum albumin (BSA) like esterase and cysteine reactivity were also evaluated in the presence of ZnO NPs. The results indicate that the ZnO NPs showed static as well as dynamic binding interaction with BSA, reduced the content of glycation products and prevented the glycation induced aggregation and antioxidant properties. Therefore, these findings suggest that ZnO NPs may be used for drug delivery agents and antiglycating as well as an antioxidant agent. Communicated by Ramaswamy H. Sarma

Inhibition of Protein Glycation by Combined Antioxidant and Antiglycation Constituents from a Phenolic Fraction of Sage (Salvia officinalis L.).

Disturbed advanced glycation end products (AGEs)-oxidative stress axis is strongly linked to vascular complications observed in diabetes and other metabolic conditions. Salvia officinalis L. (sage) is a medicinal plant used as an ingredient in foods and beverages and displays a wide range of biological and pharmacological activities including anti-diabetic effects. However, no study has assessed its anti-glycative potential. The aim of this study is to determine the phenolic compounds associated with the anti-glycation and antioxidant potential of sage methanol extract (SME). SME shows similar effects to aminoguanidine on fluorescent AGEs inhibition. It protects albumin damage from glycation (52.9 vs. 50.3%, respectively) by preventing the loss of protein thiol groups (50.0 vs. 44.3%, respectively) and by reducing protein carbonyl accumulation (67.4 vs. 70.5%, respectively). Moreover, linear regression and multivariate analysis support the efficient contribution of SME antioxidant capacity, as judged by DPPH, TBARS and iron chelating tests, in AGEs suppression. Furthermore, HPLC analysis revealed the presence of verbascoside as a novel phenolic constituent identified in sage leaves and suggests that the protective activity is mostly assigned to the presence of rosmarinic acid, resveratrol, quercetin, rutin and luteolin-7-O-glucoside. Likewise, the screening of SME phenolic content supports the contribution of various antioxidant substances to the observed effects. Therefore, a polyphenol enriched sage extract was able to inhibit the formation of AGEs and protein glycation. Our data unveils the promising properties of sage and its bioactive principles in the management of AGEs-mediated vascular complications observed in diabetes and other metabolic disorders.

Effects of Bidens gardneri Baker leaves aqueous extract in glucose homeostasis of rats

Bidens gardneri Baker, popularly known as “picão-vermelho”, has been used, traditionally, as a medicinal plant for the treatment of Diabetes mellitus. This study aimed to evaluate antidiabetic effect of leaves from B. gardneri aqueous extract (BGAE). We also evaluated in vitro anti-glycation potential. Chemical composition was analyzed based on a colorimetrics and HPLC methods. The oral glucose tolerance test (OGTT), was performed in rats with different doses (30, 100 and 300 mg/kg). Alloxan-induced diabetic and hypercaloric diet-fed rats were treated with 300 mg/kg of BGAE, orally, for 10 days and then 10 weeks, respectively. The activity of intestinal disaccharidases (maltase, sucrase and lactase) and quantification of muscle and liver glycogen content were also evaluated. On chemical analysis, the extract showed high phenolics content and the chromatogram showed 4-O-caffeoylquinic acid as the major component. The extract presented inhibition in the formation of advanced glycation end products (AGEs) and disaccharidases activity. In OGTT the dose of 300 mg/kg significantly decreased the blood glucose. In diabetic animals, BGAE significantly decreased blood glucose levels, preventing weight loss. In addition, in hypercaloric diet-fed rats, the extract prevented hyperglycemia. Our results suggest that, aqueous extract of B. gardneri has a potential for therapeutic intervention of diabetes.

A biochemical & biophysical study on in-vitro anti-glycating potential of iridin against d-Ribose modified BSA

Non-enzymatic protein glycation results in the formation of advanced glycation end products (AGEs) leads to the pathogenesis of long-term diabetic complications. Iridin (ID), an antioxidant, plays an important role in protecting against oxidative stress and could therefore be an efficacious anti-glycating regimen. Herein, we assessed the anti-glycating potential of ID against d-ribose induced glycation of bovine serum albumin (BSA) by various biophysical and biochemical techniques. Our results from several physicochemical assays advocated that ID was able to evidently prevent the AGEs generation via reducing hyperchromicity, early glycation products (EGPs), carbonyl content (CC), hydroxymethyl furfural (HMF) content, production of fluorescent AGEs, protection against loss of secondary structure (i.e. α-helix and β-sheets) of proteins, increasing the free lysine and free arginine content, reduced binding of congo red (CR), and reduced thioflavin T (ThT) and 8-aninilo-1-napthalene sulphonate (ANS)-specific fuorescence in glycated-BSA (Gly-BSA). On the basis of these findings, we concluded that ID possesses the significant anti-glycation potential and may be established as a remarkable anti-AGEs therapeutic agent. Further in-vivo and clinical studies are still warranted to uncover the therapeutic effects of ID against age-related as well as metabolic diseases.

Molecular characteristics of gallocatechin gallate affecting protein glycation

As one of the most reactive dicarbonyl compounds, methylglyoxal (MGO) can react with protein to form advanced glycation end products (AGEs), then promoting the development of diabetic complications. Hence, it is significant for preventing protein glycation mediated by MGO. Here, the anti-glycation potential and mechanism of gallocatechin gallate (GCG) as an active ingredient of green tea were investigated. It was found that GCG exhibit good scavenging activities of O2.- and .OH radicals of lysine–MGO system by 92.9% and 15.6%, respectively. The inhibitions (%) of GCG at 354.0 μg/mL for AGEs, dityrosine and N-formylkynurenine in bovine serum albumin (BSA)–MGO system were 96.7%, 97.3% and 98.2%, respectively. GCG (17.8–354.0 μg/mL) trapped MGO in a dose-dependent manner, 82.5% of MGO was trapped and the trapping efficiency reached 46.6% within 12 h when the concentration of GCG was 354.0 μg/mL. Two GCG–mono-MGO adducts were found when the molar ratios of MGO to GCG were 1:3 and 1:6. The efficacy of GCG in recovering the amino groups content, tryptophan residues and hydrophobic pockets of BSA was weak. The binding constant between GCG and BSA was in the order of magnitude of 104 L/mol, and the simulation analysis showed that the GCG–BSA complex was stable. It was inferred that the molecular mechanism of GCG against protein glycation induced by MGO may be due to its scavenging activity of O2.- and .OH radicals, MGO trapping capability and BSA binding interaction. These results suggested that GCG may be a potential inhibitor of MGO-induced glycation and provide new insights into GCG as a dietary supplement in functional foods for ameliorating the diabetic complications of MGO-derived AGEs.

Antioxidant and anti-glycation potential of green pepper (Piper nigrum): Optimization of β-cyclodextrin-based extraction by response surface methodology

Green pepper (Piper nigrum) presents high levels of functional compounds, with antioxidant and anti-glycation properties. Thus, the optimization of the β-cyclodextrin-based extraction of functional compounds from green pepper through Response Surface Methodology was performed. The optimum extraction conditions were assessed by optimizing total polyphenolic content (TPC) and antioxidant activity (DPPH• and FRAP methods). 15 mM for β-CD solution, 5 min of ultrasonication and 41 °C were the optimum extraction conditions, with the TPC of 24.9 mg GAE/mL and the anti-radical activities were 3.1 mg GAE/mL (DPPH• assay) and 0.45 mg GAE/mL (FRAP method). This natural extract obtained through eco-friendly techniques proved to be effective to reduce the formation of hydroxymethylfurfural, a glycation marker, at 70 and 80 °C. GPE presented higher TPC than black and white pepper. The relationship between the antioxidant and anti-glycation properties was confirmed and green pepper and can be proposed as a natural potential anti-glycation agent.

Inhibitory potential of proanthocyanidins from the fruit pulp of Clausena lansium (Lour.) Skeels against α-glucosidase and non-enzymatic glycation: Activity and mechanism

Inhibiting the activity of α-glucosidase and glycosylation of protein is an important way to treat diabetes mellitus and its complications. In this study, we investigated the anti-α-glucosidase activity, anti-glycation potential and structure of proanthocyanidins from fruit pulp of Clausena lansium (Lour.) Skeels. C. lansium fruit pulp proanthocyanidins showed a remarkable inhibition against α-glucosidase activity with IC50 vaule of 0.26 ± 0.01 μg/mL in a competitive manner, and quenched the fluorescence of α-glucosidase by forming proanthocyanidin-α-glucosidase complex. Furthermore, compared to positive agent aminoguanidine (AG), the proanthocyanidins were the more significant inhibitors of non-enzymatic glycation by strongly inhibiting the formation of α-dicarbonyl compounds and advanced glycation end products. In addition, the structure of the proanthocyanidins was characterized in detail. These compounds were mainly composed of prodelphinidins, and their gallates. The main extender units, gallocatechin epigallocatechin and their gallates, were critical factor of the strong anti-α-glucosidase and anti-glycation activity. Therefore, this study authenticated a efficient α-glucosidase inhibitors and antiglycation agents, which would contribute to the development of anti-diabetic drug.

Antioxidant and Antiglycation Potential of Essential Oil Extracts from Leaves and Stems of Erythroxylum monogynum Roxb.

Antioxidant and Antiglycation Potential of Essential Oil Extracts from Leaves and Stems of Erythroxylum monogynum Roxb.

In-Vitro Antioxidant, Hypoglycemic Activity, and Identification of Bioactive Compounds in Phenol-Rich Extract from the Marine Red Algae Gracilaria edulis (Gmelin) Silva.

Obesity and diabetes are major metabolic disorders which are prevalent worldwide. Algae has played an important role in managing these disorders. In this study, Gracilaria edulis, a marine red algae, was investigated for antioxidant and hypoglycemic potential using in vitro models. De-polysaccharide methanol extract of G. edulis was sequentially partitioned with hexane, chloroform, ethyl acetate, and antioxidants, and hypoglycemic potentials were evaluated using multiple methods. High antioxidant potential was observed in the ethyl acetate fraction in terms of ferric reducing antioxidant power, iron chelating, and DPPH and ABTS radical scavenging activities, while the crude methanol extract exhibited potent oxygen radical-absorbance capacity. Potent α-amylase inhibitory activity was observed in the ethyl acetate fraction, while the ethyl acetate fraction was effective against α-glucosidase inhibition. Glucose diffusion was inhibited by the ethyl acetate fraction at 180 min, and the highest antiglycation activity was observed in both chloroform and ethyl acetate fractions. Additionally, gas chromatography-mass spectrometry analysis of the ethyl acetate fraction revealed the presence of several potent anti-diabetic compounds. In conclusion, G. edulis exhibited promising antidiabetic potential via multiple mechanisms. The ethyl acetate fraction exhibited the strongest hypoglycemic and antiglycation potential among the four fractions, and hence the isolation of active compounds is required to develop leads for new drugs to treat diabetes.

Bis-coumarins; non-cytotoxic selective urease inhibitors and antiglycation agents

The current study is concerned with the identification of lead molecules based on the bis-coumarin scaffold having selective urease inhibitory and antiglycation activities. For that purpose, bis-coumarins (1-44) were synthesized and structurally characterized by different spectroscopic techniques. Eight derivatives 4, 8-10, 14, 17, 34, and 40 demonstrated urease inhibition in the range of IC50 = 4.4 ± 0.21–115.6 ± 2.13 μM, as compared to standard thiourea (IC50 = 21.3 ± 1.3 μM). Especially, compound 17 (IC50 = 4.4 ± 0.21 μM) was found to be five-fold more potent than the standard. Kinetic studies were also performed on compound 17 in order to identify the mechanism of inhibition. Kinetic studies revealed that compound 17 is a competitive inhibitor. Antiglycation activity was evaluated using glycation of bovine serum albumin by methylglyoxal in vitro. Compounds 2, 11-13, 16, 17, 19–22, 35, 37, and 42 showed good to moderate antiglycation activities with IC50 values of 333.63–919.72 μM, as compared to the standard rutin (IC50 = 294.46 ± 1.5 μM). Results of both assays showed that the compounds with urease inhibitory activity did not show any antiglycation potential, and vice versa. Only compound 17 showed dual inhibition potential. All compounds were also evaluated for cytotoxicity. Compounds 17, 19, and 37 showed a weak toxicity towards 3 T3 mouse fibroblast cell line. All other compounds were found to be non-cytotoxic. Urease inhibition is an approach to treat infections caused by ureolytic bacteria whereas inhibition of glycation of proteins is a strategy to avoid late diabetic complications. Therefore, these compounds may serve as leads for further research.

Synthesis, biological evaluation, molecular docking and structure-activity relationship studies of halogenated quinone and naphthoquinone derivatives

Protein glycation, oxidative stress and acetyl cholinesterase enzyme (AChE) are closely implicated in the pathogenesis of diabetic complications and Alzheimer's disease. In this study, we synthesized a series of previously unexplored molecular analogues of halogenated quinone and naphthoquinone to investigate their therapeutic potency against protein glycation, free radical production and acetyl cholinesterase enzyme.The study on protein glycation resulted in the identification of two novel antiglycation agents such as 2,3-dichloronaphthalene-1,4-bistriflate (3) and 2,3-dibromonaphthalene-1,4-bis (trifluoromethanesulfonate) (6) with IC50 values less than 16 micromolar range. Moreover, 2,3-dichloro-1,4- naphthoquinone (DCNQ) (1), 2,3-dibromonaphthoquinone (4), 2,3-dibromonaphthalene-1,4-diol (5) and 2,3,5,6-tetrachlorobenzene-1,4-bis(trifluoromethane- sulfonate) (8) exhibited potent antiglycation activity with IC50 values of 54 ± 1.02, 43 ± 0.5, 65 ± 1.00 and 60 ± 1.25 μM, respectively as compared to the standard inhibitor rutin with an IC50 value of 98 ± 1.50 μM. The structure-activity relationship (SAR) demonstrated that the presence of bis-(trifluoromethanesulfonate) as substituents alongwith halogens moieties appreciably influenced inhibitory potential and enhanced the antiglycation potential significantly. On free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay, 2,3,5,6-tetrachlorobenzene-1,4-bis(trifluoromethane- sulfonate) (8), showed significant antioxidant activity with IC50 values 52 ± 1.50 μM. On acetyl cholinesterase inhibition assay, compound 8 and 2,3-dichloronaphthalene-1,4-bistriflate 3, exhibited considerable inhibition with IC50 values of 98 ± 1.00 μM and 124 ± 1.50 μM, respectively. The SAR studies against AChE revealed that the presence of chlorine and trifluoromethanesulfonate both combined together in a compound enhanced its inhibitory activity several folds. In support of experimental observations, molecular docking studies with the active site of acetyl cholinesterase also confirmed the stronger inhibition of compounds 3, and 8 compared to others derivatives. These inhibitors demonstrated hydrogen bonding with Tyr124 and π-π stacking with Tyr341 of the active site residues. In this study, galantamine, rutin and propyll gallate were used as standard inhibitors, respectively.

Oxindole-based chalcones: synthesis and their activity against glycation of proteins

Diabetes mellitus, a metabolic disorder, is characterized by a substantial hyperglycaemia. Prevalence of hyperglycaemia for longer period of time can cause nonenzymatic condensation of sugar in blood with amino group of protein and give rise to advanced glycation end products (AGEs). AGEs play a major role in the onset of late diabetic complications including diabetic retinopathy, nephropathy, neuropathy and cardiovascular diseases. There is a need to establish potential therapeutic regimens that can effectively inhibit the formation of AGEs. To this end a series of novel oxindole-based chalcones have been investigated for their antiglycation potential. Analogues 1 (IC50 = 155.22 ± 2.98 µM), 3 (IC50 = 195.95 ± 0.43 µM), 4 (IC50 = 289.47 ± 2.47 µM), 5 (IC50 = 222.44 ± 4.03 µM), 7 (IC50 = 251.27 ± 2.80 µM), and 20 (224.23 ± 1.93 µM) showed potent inhibitory activity against glycation compared to the reference Rutin (IC50 = 294.5 ± 1.5 µM). These results reveal that multiple hydroxyl substituents and their position on the aromatic ring play a key role in inhibitory effect due to their hydrogen bonding potential. The study also reveals the influence of substituents on the binding capabilities and in turn inhibitory potential of different analogues.

Using Neuroscience, Contemporary methods and Traditional Wisdom in Building Well-being in Long Term Unemployed Youth

Advanced glycation end-products (AGEs) from non-enzymatic glycation are implicated in several degenerative diseases, including being a crucial contributor in secondary complications of diabetes. This has garnered significant scientific interest in inhibiting agents of AGEs to prevent and remediate disorders arising due to glycation. In the current study, inhibitory effects on AGEs formation were investigated using bio-enzymatically synthesized nanoformulations of gold (AuNPs) and silver (AgNPs) by physiologically important enzyme, β galactosidase. Human serum albumin, most abundant protein in human blood plasma, was glycated by incubating with glucose leading to AGEs formation. The AGEs formation was significantly minimized with both AuNPs and AgNPs, as confirmed by various biophysical and biochemical techniques. Circular dichroism and Fourier transform infrared spectroscopy further affirmed antiglycation potential of AuNPs and AgNPs. The results were corroborated with thiol group, free lysine and carbonyl content estimation for native, glycated and nanoparticles (NPs) treated samples. Confocal microscopic imaging was performed to exhibit glycation inhibiting potential of the NPs. The inhibition of AGEs was observed to be slightly stronger in case of AgNPs than AuNPs with both exhibiting promising results as potential anti-glycating agents. The study sheds light on potential of non-toxic NPs being utilized as controlling agents against hyperglycemic conditions and diabetes management.

Inhibitory effect of epicatechin gallate on protein glycation.

Protein glycation can produce the advanced glycation end products (AGEs), which has a potential health risk due to its relevance with diabetic complications. Searching for potent inhibitors to suppress hyperglycemia-induced protein glycation is of great significance. Here, we probed the anti-glycation potential of epicatechin gallate (ECG), an important ingredient of green tea, by spectroscopy and chromatography supplemented by molecular docking. It was found that ECG suppressed the carbonylation and the formation of amyloid cross-β structures of bovine serum albumin (BSA) as well as the generation of AGEs in BSA-fructose model by 65.6%, 73.7% and 87.0%, resepctively. A combination of ECG with epigallocatechin gallate (EGCG) at molar ratios from 0.5:1 to 2:1 exhibited the interactive effects on AGEs formation from moderate antagonism to synergy. Moreover, ECG at 44.2 μg/mL showed a trapping efficiency of 81.6% for the important precursor methylglyoxal (MGO) of AGEs within 24 h, and the formed ECG-mono-MGO and ECG-di-MGO adducts were verified by LC-QqQ-MS analysis. The inhibitory effect of ECG on the protein glycation may be due to its MGO trapping and the specific binding with certain amino acid residues of BSA. These findings may provide the theoretical basis for the development of ECG as an inhibitor of protein glycation.

Pectin oligosaccharides from fruit of Actinidia arguta: Structure-activity relationship of prebiotic and antiglycation potentials

Pectin oligosaccharides (POSs) have prebiotic and antiglycation activities in vitro, but the specific structure-activity relationship is unclear. In this study, POSs were obtained by enzymatic and ultrasound-assisted enzymatic degradation of pectin polysaccharide (PPS), respectively. Based on the chemical characterization, the antiglycation in vitro and prebiotic activities of POSs were compared and the structure-activity relationship was studied. The results showed that the antiglycation activity of POSs in vitro was proportional to the galacturonic acid content and GalA:Rha molar ratios except for the low molecular weight POSs (LM-POSs), and inversely proportional to its branching degree, such as Ara:Rha and Gal:Rha molar ratios. In addition, it was also found that the prebiotic activity of POSs was positively correlated with Ara:Rha and Gal:Rha molar ratios in molecule composition and the neutral sugar content, especially galactose and arabinose. The degree of esterification (DE) was less important for both antiglycation and prebiotic activity of POSs. These results provided an important theoretical basis for POSs application in food.

Suppression in advanced glycation adducts of human serum albumin by bio-enzymatically synthesized gold and silver nanoformulations: A potential tool to counteract hyperglycemic condition

Advanced glycation end-products (AGEs) from non-enzymatic glycation are implicated in several degenerative diseases, including being a crucial contributor in secondary complications of diabetes. This has garnered significant scientific interest in inhibiting agents of AGEs to prevent and remediate disorders arising due to glycation. In the current study, inhibitory effects on AGEs formation were investigated using bio-enzymatically synthesized nanoformulations of gold (AuNPs) and silver (AgNPs) by physiologically important enzyme, β galactosidase. Human serum albumin, most abundant protein in human blood plasma, was glycated by incubating with glucose leading to AGEs formation. The AGEs formation was significantly minimized with both AuNPs and AgNPs, as confirmed by various biophysical and biochemical techniques. Circular dichroism and Fourier transform infrared spectroscopy further affirmed antiglycation potential of AuNPs and AgNPs. The results were corroborated with thiol group, free lysine and carbonyl content estimation for native, glycated and nanoparticles (NPs) treated samples. Confocal microscopic imaging was performed to exhibit glycation inhibiting potential of the NPs. The inhibition of AGEs was observed to be slightly stronger in case of AgNPs than AuNPs with both exhibiting promising results as potential anti-glycating agents. The study sheds light on potential of non-toxic NPs being utilized as controlling agents against hyperglycemic conditions and diabetes management.

Effect of Cinnamon and its Procyanidin-B2 on Diabetic Retinopathy in Rats

<p><em>Advanced glycation end products (AGE) are amalgamated in the development of certain pathophysiologies including diabetic retinopathy (DR). Procyanidin-B2 (PCB2), an active principle of cinnamon, has shown to inhibit AGE formation</em><em>. In current study we inspected the protective role of PCB2 to prevent DR in diabetic rats.<strong> </strong>Diabetes was induced in Wistar-NIN rats by intraperitoneal injection of streptozotocin (35 mg/kg bodyweight) and the control rats received vehicle alone. The retinal morphology was studied by microscopy and immunohistochemistry of diabetic and control rats. The expression of retinal selective genes analysis was done via real-time PCR. Immunoblotting of diabetic and control rat retina was studied. Gene expression and immunohistochemistry and immunofluorescence analysis of diabetic retina from PCB2 and cinnamon fed rat showed declined expression of VEGF and GFAP and increased expression of NGF. Immunoblotting analysis resulted that feeding of PCB2 significantly reserved the formation of carboxy methyl lysine and RAGE in diabetic rats compare with controls. The results indicate that PCB2 was effective in protecting the diabetic retina from development of diabetic retinopathy in rats owing to its antiglycating potential. Thus, active principle of dietary sources, such as PCB2, may be explored for the prevention or delay of DR.<strong></strong></em></p>

Glycation and HMG-CoA Reductase Inhibitors: Implication in Diabetes and Associated Complications.

Diabetes Mellitus (DM) acts as an absolute mediator of cardiovascular risk, prompting the prolonged occurrence, size and intricacy of atherosclerotic plaques via enhanced Advanced Glycation Endproducts (AGEs) formation. Moreover, hyperglycemia is associated with enhanced glyco-oxidized and oxidized Low-Density Lipoprotein (LDL) possessing greater atherogenicity and decreased the ability to regulate HMG-CoA reductase (HMG-R). Although aminoguanidine (AG) prevents the AGE-induced protein cross-linking due to its anti-glycation potential, it exerts several unusual pharmaco-toxicological effects thus restraining its desirable therapeutic effects. HMG-R inhibitors/ statins exhibit a variety of beneficial impacts in addition to the cholesterol-lowering effects. Inhibition of AGEs interaction with receptor for AGEs (RAGE) and glyco-oxidized-LDL by HMG-R inhibitors could decrease LDL uptake by LDL-receptor (LDL-R), regulate cholesterol synthesis via HMG-R, decrease oxidative and inflammatory stress to improve the diabetes-associated complications. Current article appraises the pathological AGE-RAGE concerns in diabetes and its associated complications, mainly focusing on the phenomenon of both circulatory AGEs and those accumulating in tissues in diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy, discussing the potential protective role of HMG-R inhibitors against diabetic complications.

Potential Antiglycation and Hypoglycaemic Effects of Toona ciliata M. Roem. and Schkuhria pinnata Lam. Thell. Crude Extracts in Differentiated C2C12 Cells.

Medicinal plants have been identified as a feasible avenue for the development of new potent antidiabetic agents. The phytoconstituent compositions of different Toona ciliata and Schkuhria pinnata extracts were determined and quantified using standard chemical methods after exhaustive extraction. Thereafter, their antioxidant and antiglycation potentials were spectrophotometrically determined. The cytotoxicity profiles of the extracts on C2C12 cells were determined using the MTT assay. Toona ciliata methanol extract resulted in the highest percentage yield (20.83%) and high total phenols and flavonoids content in the methanol and acetone extracts compared to S. pinnata extracts. The acetone extract of T. ciliata showed good activity in the DPPH scavenging and FRAP assays with EC50 values of 1.90 mg/ml and 5.26 mg/ml, respectively. Arbutin's antiglycation ability was outperformed by treatments with the methanol, acetone, and hexane extract of T. ciliata which resulted in 2.49%, 2.79%, and 2.56% glycation, respectively. The hexane extract of T. ciliata was less toxic to C2C12 cells as compared to the other extracts with CC50 value of 402.16 μg/ml. Only the hexane extract of S. pinnata resulted in glucose utilisation of 28.56% which was higher than that of insulin (26.06%) after 6 hours and is therefore considered as the most potent extract with hypoglycaemic potential in this study. Studies are ongoing aimed at identifying drug candidates in this extract that may be employed in the development of hypoglycaemic, antioxidant, and antiglycation agents.

Extraction optimization, antidiabetic and antiglycation potentials of aqueous glycerol extract from rice (Oryza sativa L.) bran

The purpose of this investigation was to explore aqueous glycerol as food grade solvent for rice bran polyphenolic antioxidants extraction and investigate the antidiabetic and antiglycation potential of the extract and its major polyphenols. Response surface methodology (Box-Behnken design) was implemented to optimize experimental conditions for rice bran polyphenols and antioxidants extraction. The optimum conditions provided a very satisfactory outcome in total polyphenols (549.6 ± 8.05 mg gallic acid equivalent per 100 g dry weight) and DPPH scavenging activity (57.83 ± 1.8%). The chromatographic separation of the extract showed higher concentrations of ferulic acid, ρ-coumaric acid and chlorogenic acid followed by caffeic acid, syringic acid and rutin. Moreover, the extract inhibited α-amylase, α-glucosidase, and lipase activity as 34.2 ± 3.2%, 29.9 ± 1.0%, and 12.4 ± 2.3%, respectively. Furthermore, fructose readily forms Advanced Glycation End Products (AGEs) fluorescence with basic amino acids in low concentration in simulated intestinal digestion conditions. The extract inhibited AGEs formation by 52.6% at 20 μL/mL. Our study indicated that the antidiabetic and antiglycation potential of rice bran extract was mainly driven by the extract polyphenols. Rice bran glycerol extract could be employed as a natural antidiabetic and antiglycation remedy, and as economically and eco-friendly source of potent bioactive compounds with satisfactory outcome.