Troxerutin imparts preservative effects on albumin by preventing Maillard reaction-mediated early and advanced glycation modification

Insights into the conformational, secondary structural, dynamical and hydration pattern changes of glucose mediated glycated HSA: a molecular dynamics approach

The robust structural nature of human serum albumin (HSA) is responsible for its multifarious functional property. The site specific glycation of HSA due to hyperglycaemia (excess glucose) causes structural changes which have an impact on the functioning of the protein. This work investigates the effects of glucose-mediated glycation in the altered inter-domain motion, distorted binding site conformation and modified hydration patterns, Trp214 orientation, and secondary structure transition using simulation approach. Here we have observed an increase of turns in the helices of glycated HSA, which modulates the open-close conformation of Sudlow I & II. The secondary structure changes of glycated HSA indicate plausible reduction in the alpha helical content in the helices which participates in ligand binding. It also affects geometrical features of drug binding sites (Sudlow I and II) such as volume and hydration. We found that glycation disturbs domain specific mobility patterns of HSA, a substantial feature for albumin drug binding ability which is also correlated with changes in the local environment of Trp214.Communicated by Ramaswamy H. Sarma.

Conformational variation of site specific glycated albumin: A Molecular dynamics approach

Human serum albumin (HSA) is a major cargo protein, which undergoes glycation in hyperglycaemic conditions and results in impaired function. In physiological conditions, HSA plays a crucial role in pharmacological activities such as drug transport or delivery through its binding capacity and also by its enzymatic activity, which enables the translation of pro-drugs into active drugs. In this study, the impact of the methylglyoxal-mediated glycation on dynamic behaviour of inter-domain motion, Cys34 reactivity, binding site residual interaction and secondary structure transition were investigated through molecular dynamics simulation. The alteration in inter-domain motion reflects the effect of glycation-mediated changes on the structural conformation of albumin. The binding site residue interactions and volume analysis revealed the impact of glycation on the geometry of the binding site. We also found the correlation of Cys34 reactivity with increase of turns in the region between Ia-h4 and Ia-h5. The rise in turn formation in that region keeps Tyr84 farther away from Cys34 which could lead to higher Cys34 reactivity. In parallel, significant alterations in alpha helical content of helices in the binding sites were observed. These structural and conformational changes in glycated albumin could be the causative agents for functional impairment which leads to diabetic complications.

The Protective Roles and Molecular Mechanisms of Troxerutin (Vitamin P4) for the Treatment of Chronic Diseases: A Mechanistic Review

Troxerutin (TRX), a semi-synthetic bioflavonoid derived from rutin, has been reported to exert several pharmacological effects including antioxidant, anti-inflammatory, antihyperlipidemic, and nephroprotective. However, the related molecular details and its mechanisms remain poorly understood. In the present review, we presented evidences from the diversity in vitro and in vivo studies on the therapeutic potential of TRX against neurodegenerative, diabetes, cancer and cardiovascular diseases with the purpose to find molecular pathways related to the treatment efficacy. TRX has a beneficial role in many diseases through multiple mechanisms including, increasing antioxidant enzymes and reducing oxidative damage, decreasing in proapoptotic proteins (APAF-1, BAX, caspases-9 and-3) and increasing the antiapoptotic BCL-2, increasing the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and downregulating the nuclear factor κB (NFκ). TRX also reduces acetylcholinesterase activity and upregulates phosphoinositide 3- kinase/Akt signaling pathway in Alzheimer's disease models. Natural products such as TRX may develop numerous and intracellular pathways at several steps in the treatment of many diseases. Molecular mechanisms of action are revealing novel, possible combinational beneficial approaches to treat multiple pathological conditions.

Biosynthesized ZnO-NPs from Morus indica Attenuates Methylglyoxal-Induced Protein Glycation and RBC Damage: In-Vitro, In-Vivo and Molecular Docking Study

The development of advanced glycation end-products (AGEs) inhibitors is considered to have therapeutic potential in diabetic complications inhibiting the loss of the biomolecular function. In the present study, zinc oxide nanoparticles (ZnO-NPs) were synthesized from aqueous leaf extract of Morus indica and were characterized by various techniques such as ultraviolet (UV)-Vis spectroscopy, Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Further, the inhibition of AGEs formation after exposure to ZnO-NPs was investigated by in-vitro, in-vivo, and molecular docking studies. Biochemical and histopathological changes after exposure to ZnO-NPs were also studied in streptozotocin-induced diabetic rats. ZnO-NPs showed an absorption peak at 359 nm with a purity of 92.62% and ~6-12 nm in size, which is characteristic of nanoparticles. The images of SEM showed agglomeration of smaller ZnO-NPs and EDS authenticating that the synthesized nanoparticles were without impurities. The biosynthesized ZnO-NPs showed significant inhibition in the formation of AGEs. The particles were effective against methylglyoxal (MGO) mediated glycation of bovine serum albumin (BSA) by inhibiting the formation of AGEs, which was dose-dependent. Further, the presence of MGO resulted in complete damage of biconcave red blood corpuscles (RBCs) to an irregular shape, whereas the morphological changes were prevented when they were treated with ZnO-NPs leading to the prevention of complications caused due to glycation. The administration of ZnO-NPs (100 mg Kg^-1) in streptozotocin(STZ)-induced diabetic rats reversed hyperglycemia and significantly improved hepatic enzymes level and renal functionality, also the histopathological studies revealed restoration of kidney and liver damage nearer to normal conditions. Molecular docking of BSA with ZnO-NPs confirms that masking of lysine and arginine residues is one of the possible mechanisms responsible for the potent antiglycation activity of ZnO-NPs. The findings strongly suggest scope for exploring the therapeutic potential of diabetes-related complications.

Dual Glycation-Inflammation Modulation, DPP-IV and Pancraetic Lipase Inhibitory Potentials and Antiproliferative Activity of Novel Fluoroquinolones

Paramount efforts by pharmaceutical industry to identify new targets for obesity-diabetes (Diabesity) pharmacological intervention have led to a number of agents developed and directed at DPP IV [dipeptidyl peptidase IV] enzyme inhibition thereby enhancing endogenous insulinotropic incretins. Besides antioxidative-antiinflammtory molecules that inhibit accumulation of advanced glycation end products (AGEs) can be good candidates for ameliorating diabetic complications. Fluoroquinolones (FQs) have been identified recently as potent inhibitors of pancreatic lipase (PL). The suggested association between obesity and colorectal cancer initiated the evaluation of antiproliferative activity of the new FQs and TFQs against a panel of obesity related colorectal cells (HT29, HCT116, SW620 CACO2 and SW480). The aim of the current study is to examine the potential of newly synthesized FQs and triazolofluoroquinolones (TFQs) derivatives as dual inhibitors for glycation and inflammation, DPP IV inhibitors, PL inhibitors for dual management of obesity and diabetes, as well as antiprolifertaive efficacy against colorectal cancer cell lines. Sulforodamine B (SRB) colorimetric assay revealed that some derivatives exhibited unselective cytotoxity against HT29, HCT116, SW620 CACO2 and SW480. The superior antiglycation activity of the reduced derivatives 4a and 4b over that of aminoguanidine with respective IC50 (μM) values of 3.05±0.33 and 8.51±3.21; none of the tested synthetic compounds could perform equally effectively to Diprotin A, a dose dependent inhibitor of DPP IV. Compounds 4a, 5a, 3b, 4b and 5b demonstrated anti-inflammatory IC50 values exceeding that of indomethacin. Compounds 3a and 4a showed IC50 lower than 10 μM as PL inhibitors. In conclusion, FQ and TFQ derivatives may unveil new antiobesity and anticancer agents in the future. Our research qualifies FQs and TFQs as promising candidates for the development of related α-dicarbonyl scavengers as therapeutic agents to protect cells against carbonyl stress.