Homeopathic Formulations of Syzygium jambolanum Alleviate Glycation-Mediated Structural and Functional Modifications of Albumin: Evaluation through Multi-Spectroscopic and Microscopic Approaches.

BACKGROUND: The growing interest in identifying the mode of action of traditional medicines has strengthened its research. Syzygium jambolanum (Syzyg) is commonly prescribed in homeopathy and is a rich source of phytochemicals. OBJECTIVE: The present study aims to shed light on the anti-glycation molecular mechanism of Syzyg mother tincture (MT), 30c, and 200c on glycated human serum albumin (HSA) by multi-spectroscopic and microscopic approaches. METHODS: The phytochemicals and antioxidant potential of the Syzyg formulations were estimated by the high-performance liquid chromatography and spectroscopic technique, respectively. Glycation was initiated by incubating HSA with methylglyoxal, three Syzyg formulations, and the known inhibitor aminoguanidine in separate tubes at 37°C for 48 hours. The formation of glycation adducts was assessed by spectrofluorometer and affinity chromatography. The structural modifications were analyzed through circular dichroism, Fourier transform infrared spectroscopy, turbidity, 8-anilinonapthalene-1-sulfonic acid fluorescence, and nuclear magnetic resonance. Further, the formation of the aggregates was examined by thioflavin T, native-polyacrylamide gel electrophoresis, and transmission electron microscopy. Additionally, the functional modifications of glycated HSA were determined by esterase-like activity and antioxidant capacity. The binding analysis of Syzyg formulations with glycated HSA was evaluated by surface plasmon resonance (SPR). RESULTS: Syzyg formulations MT, 30c, and 200c contained gallic acid and ellagic acid as major phytochemicals, with concentrations of 16.02, 0.86, and 0.52 µg/mL, and 227.35, 1.35, and 0.84 µg/mL, respectively. Additionally, all three formulations had remarkable radical scavenging ability and could significantly inhibit glycation compared with aminoguanidine. Further, Syzyg formulations inhibited albumin's structural and functional modifications. SPR data showed that Syzyg formulations bind to glycated HSA with an equilibrium dissociation constant of 1.10 nM. CONCLUSION: Syzyg formulations inhibited the glycation process while maintaining the structural and functional integrity of HSA.

Attenuation of glycation-induced multiple protein modifications by Indian antidiabetic plant extracts.

CONTEXT: Protein glycation is the major contributing factor in the development of diabetic complications. The antiglycation potential of medicinal plants provides a promising opportunity as complementary interventions for complications. OBJECTIVE: To investigate the antiglycation potential of 19 medicinal plants extracts using albumin by estimating different indicators: (1) glycation (early and late), (2) albumin oxidation, and (3) amyloid aggregation. MATERIALS AND METHODS: The effect of aqueous plant extracts (1% w/v) on protein glycation was assessed by incubating albumin (10 mg/mL) with fructose (250 mM) for 4 days. Degree of protein glycation in the absence and presence of plant extracts was assessed by estimating fructosamine, advanced glycation end products (AGEs), carbonyls, free thiol group and ß-amyloid aggregation. RESULTS: Petroselinum crispum, Boerhavia diffusa, Terminalia chebula, Swertia chirayita and Glycyrrhiza glabra showed significant antiglycating activity. P. crispum and A. barbadensis inhibited the carbonyl stress and protected the thiol group from oxidative damage. There was significant correlation between protein thiols and amyloid inhibition (R = -.69, p < .001). CONCLUSION: P. crispum, B. diffusa and T. chebula had the most potent antiglycation activity. These plant exerted noticeable antiglycation activity at different glycation modifications of albumin. These findings are important for identifying plants with potential to combat diabetic complications.

Aqueous extract of some indigenous medicinal plants inhibits glycation at multiple stages and protects erythrocytes from oxidative damage-an in vitro study.

Azadirachta indica, Emblica officinalis, Syzygium cumini and Terminalia bellirica are common in Indian system of traditional medicine for the prevention of diabetes and its complications. The aim of the present study was to comprehensively and comparatively investigate the antiglycation potential of these plant extracts at multiple stages and their possible protective effect against glycated albumin mediated toxicity to erythrocytes. Antiglycation activities of these plant extracts was measured by co-incubation of plant extract with bovine serum albumin-fructose glycation model. The multistage glycation markers- fructosamines (early stage), protein carbonyls (intermediate stage) and AGEs (late stage) are investigated along with measurement of thiols and ß aggregation of albumin using amyloid-specific dyes-Congo red and Th T. Protection of erythrocytes from glycated albumin induced toxicity by these plant extracts was assessed by measuring erythrocytes hemolysis, lipid peroxidation, reduced glutathione and intracellular antioxidant capacity. Total phenolics, reducing power and antioxidant activities of the plant extracts were also measured. In vitro glycation assays showed that plant extracts exerted site specific inhibitory effects at multiple stages, with T. bellirica showing maximum attenuation. In erythrocytes, along with the retardation of glycated albumin induced hemolysis and lipid-peroxidation, T. bellirica considerably maintained cellular antioxidant potential. Significant positive correlations were observed between erythrocyte protection parameters with total phenolics. These plant extracts especially T. bellirica prevents glycation induced albumin modifications and subsequent toxicity to erythrocytes which might offer additional protection against diabetic vascular complications.

Nutraceutical properties of dietary plants extracts: prevention of diabetic nephropathy through inhibition of glycation and toxicity to erythrocytes and HEK293 cells.

CONTEXT: Glycated albumin is reported to elicit pathobiologic effects in diabetic nephropathy and abrogating its biologic effects has novel therapeutic potential. OBJECTIVE: This study examines the effects of dietary plants extracts (Laurus nobilis, Carum carvi, Coccinia grandis, Mentha arvensis, Phaseolus vulgaris) against albumin glycation and its toxicity to erythrocytes and HEK293 cells. MATERIALS AND METHODS: Albumin (10 mg/ml) was incubated with fructose (250 mM) in PBS along with aqueous plant extracts (1% w/v) for 4 d. After incubation, the antiglycation potential of extracts was estimated by measuring AGEs, fructosamine, amyloids, carbonyls, free amino groups, and antioxidant potential of albumin. The glycation extent of the treated samples was determined by boronate affinity chromatography. Effect of extracts against glycation induced cytotoxicity in erythrocytes and HEK 293 cells was assessed by estimating viability, glutathione, and antioxidant capacity. Plant extracts were tested for their phenolic content and antioxidant potential (reducing potential, DPPH, ABTS, NO, and H2O2 radical scavenging activities). RESULTS: Plant extracts significantly decreased the AGEs formation and amyloid aggregation in glycated BSA (p < 0.001). Further, fructosamine and carbonyls were reduced to 55-72% and 83-89%, respectively. Free amino group and antioxidant activity of albumin were also preserved by 1.25-1.40-fold and 1.75-1.8-fold, respectively. Further, co-incubation of extracts with glycated albumin, protected erythrocytes, and HEK293 cells as they inhibited cellular hemolysis/toxicity (p < 0.001) by upregulating cellular antioxidants. DISCUSSION AND CONCLUSION: Plant co-incubation reversed many modifications in albumin glycation, cellular dysfunction indicating that dietary sources with antiglycating and antioxidant potential could be considered for the effective management of diabetic nephropathy.