Ramith Ramu

Investigation of antihyperglycaemic activity of banana (Musa sp. var. Nanjangud rasa bale) pseudostem in normal and diabetic rats

BACKGROUND Postprandial hyperglycaemia in diabetes could be ameliorated by inhibiting intestinal α-glucosidases, responsible for starch hydrolysis and its absorption. Different parts of banana have been in use in conventional medicinal formulations since ancient times. Its role as an antihyperglycaemic agent has also been studied. This study was aimed at explaining the mechanism of hypoglycaemic effect by ethanol extract of banana pseudostem (EE). Additionally, studies on the active components involved in the effect have also been attempted. RESULTS EE significantly inhibited mammalian intestinal α-glucosidases and yeast α-glucosidase (IC50 , 8.11 ± 0.10 µg mL(-1) ). The kinetic studies showed that EE inhibited sucrase, maltase and and p-nitrophenyl-α-d-glucopyranoside hydrolysis by mixed-type inhibition. Further, in vivo studies identified that the oral administration (100-200 mg kg(-1) body weight) of EE significantly suppressed the maltose/glucose-induced postprandial plasma glucose elevation and wielded an antihyperglycaemic effect in normal and alloxan-induced diabetic rats. GC-MS analysis of EE revealed high levels of β-sitosterol (29.62%), stigmasterol (21.91%), campesterol (10.85%) and other compounds. CONCLUSION These findings suggest that EE might exert an anti-diabetic effect by inhibition of α-glucosidases from the intestine, in turn suppressing the carbohydrate absorption into the bloodstream. Hence the results extend a foundation to the future prospects of the food-derived enzyme inhibitors in treatment of diabetes.

Bacteriocins and Their Applications in Food Preservation.

Bacteriocins are ribosomally-synthesized antimicrobial peptides or proteinaceous compounds produced by bacterial strains. They are generally effective in inhibiting the growth of similar or closely related bacterial strains. A high diversity of various bacteriocins is produced by many lactic acid bacteria (LAB) and is found in numerous fermented and non-fermented foods. Several bacteriocins from LAB extend potential applications in food preservation, thus help foods to be naturally preserved and richer in organoleptic and nutritional properties. Though chemical preservatives for the preservation of food are successful to some extent, their quality is not as satisfying as fresh food. Hence, an alternative is required and bacteriocins serve the purpose. Nisin is currently the only bacteriocin widely used as a food preservative. Numerous bacteriocins have been characterized chemically, biochemically, genetically and also at the molecular level to understand their basic mode of action. This article gives an overview of classification of bacteriocins, isolation & characterization, and mode of action. Besides, article highlights the optimized parameters for growth of bacteria in the production of bacteriocins and various bioassays for their determination. Special emphasis has been provided on explaining the beneficial aspects of nisin.

Assessment of In Vivo Antidiabetic Properties of Umbelliferone and Lupeol Constituents of Banana (Musa sp. var. Nanjangud Rasa Bale) Flower in Hyperglycaemic Rodent Model

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana flower is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. This study is based on an investigation of the in vivo antihyperglycaemic activity of Umbelliferone (C1) and Lupeol (C2) isolated from the ethanol extract of banana flower (EF) in alloxan induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EF (100 and 200 mg/kg b. wt.) for 4 weeks showed deterioration in fasting hyperglycaemia and reversal of abnormalities in serum/urine protein, urea and creatinine, when compared to the diabetic control group of rats. The diabetic group of rats fed with EF, C1 and C2 (100 mg/kg b. wt.) once daily, for a period of 28 days resulted in a significant reduction of diabetic symptoms viz., polyphagia, polydipsia, polyuria and urine sugar together with an improved body weight. HbA1c extent was reduced whereas levels of insulin and Hb were increased. Both the extract and compounds wielded positive impacts in diabetic rats by reversal of altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase, lactate dehydrogenase) and pyruvate kinase. The characteristic diabetic complications such as hypercholesterolemia and hypertriacylglycerolemia also significantly reverted to normal in the serum/liver of diabetic rats. Besides these, the treatment increased the activities of enzymatic and non-enzymatic antioxidants in the serum and liver. The histological observations revealed a marked regeneration of the β-cells in the drug treated diabetic rats. In conclusion, the present study illustrates that EF, C1 and C2 enhances the glycolytic activities, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant β-cells along with potential enzymatic and non-enzymatic antioxidant activities.

The effect of a plant extract enriched in stigmasterol and β-sitosterol on glycaemic status and glucose metabolism in alloxan-induced diabetic rats

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana pseudostem, is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. The present study was aimed at elucidating the mechanism of antihyperglycaemia exerted by the ethanol extract of banana pseudostem (EE) and its isolated compounds viz., stigmasterol (C1) and β-sitosterol (C2), in an alloxan-induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EE (100 and 200 mg per kg b. wt.) for 4 weeks showed reduced levels of fasting blood glucose and reversal of abnormalities in serum/urine protein, urea and creatinine in diabetic rats compared to the diabetic control group of rats. Diabetic symptoms such as polyphagia, polydipsia, polyuria, urine glucose and reduced body weight were ameliorated in the diabetic group of rats fed with EE, C1 and C2 (100 mg per kg b. wt., once daily) for 28 days. The levels of insulin and Hb were also increased, while the HbA1c level was reduced. The altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase and lactate dehydrogenase) and pyruvate kinase were significantly reverted to normal levels by the administration of EE, C1 and C2. In addition, increased levels of hepatic glycogen and glycogen synthase and the corresponding decrease of glycogen phosphorylase activity in diabetic rats illustrated the antihyperglycaemic potential of EE and its components. The histological observations revealed a marked regeneration of the β-cells in the drug treated diabetic rats. These findings suggest that EE might exert its antidiabetic potential in the presence of C1 and C2, attributable to the enhanced glycolytic activity, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant β-cells.

Therapeutic Potentials of Triterpenes in Diabetes and its Associated Complications.

Diabetes is a major chronic metabolic disorder globally and around of 285 million people are affected by the disease and the number is expected to double in the next two decades. The major focus of anti-diabetic therapies is to enhance insulin production, sensitivity and/or reduce the blood glucose level. Although several synthetic drugs have been developed as antidiabetic agents but their utility has been hampered due to their side effects and poor efficacy. In this scenario, research on natural products has been gained importance due their safety profile in toxicity studies. Terpenoids belong to an important class of natural products and several terpenoids have been reported as antidiabetic agents. Some of them are under various stages of pre-clinical and clinical evaluation to develop them as antidiabetic agents. These agents can inhibit enzymes responsible for the development of insulin resistance, normalization of plasma glucose and insulin levels and glucose metabolism. Triterpenes can act as promising agents in the treatment of diabetic retinopathy, neuropathy and nephropathy or in impaired wound healing by inhibiting several pathways involved in the diabetes and associated complications. However, efforts in understanding the biological actions and clinical studies involving the applications of triterpenes in treating diabetes are very limited. Hence, special attention is imperative to explore the therapeutic potential of these compounds and provide new information to the scientific community. This review aims to provide the recent advances in triterpenes chemistry, its derivatives, biological interventions and its therapeutic applications with special emphasis on diabetes and its associated disorders.

Assessment of nutritional quality and global antioxidant response of banana (Musa sp. CV. Nanjangud Rasa Bale) pseudostem and flower

Background: The assessment of the nutritional composition and phytochemical screening of banana pseudostem (PB) and flower (FB) advocate this nonconventional food source for routine consumption, considering its various health benefits. Objectives: The aim is to assess the proximate nutrient composition, fatty acids, minerals, amino acid profile, and global antioxidant response (GAR) of PB and FB. Methods: Standard analytical procedures were used to determine the nutritional quality and GAR of PB and FB. Results: The chemical analysis illustrated that functional profile (water holding capacity, oil holding capacity, swelling power, and solubility), and proximate (ash, moisture, protein, fat, dietary fiber, and carbohydrate) contents were substantially high in FB than PB. With a well-proportionate amino acid profile, PB (0.56) and FB (0.54) comprised of a high ratio of essential to nonessential amino acids than those of FAO/WHO requirement (0.38). The mineral analysis revealed that PB and FB were rich in macro and micro minerals in the order K > Ca > Mg > P > Na and K > Mg > Na > Ca > P, respectively. Linoleic acid was found to be the major component in PB and FB. Besides, total antioxidant activity conducted for PB and FB by GAR method, measuring both bio-accessible and insoluble fractions, revealed that the soluble fraction fared better than the chemical extracts. Conclusion: The results revealed high nutritional qualities of the byproducts of banana and the low cost of its production promotes their use as a prospective nonconventional food resource with high nutraceutical value.

Investigation of antihyperglycaemic activity of banana (Musa sp. Var. Nanjangud rasa bale) flower in normal and diabetic rats

Background: The vital enzymes of starch digestion and absorption are intestinal α-glucosidases and their inhibition improves postprandial hyperglycaemia, constituting an effective mode of therapy in diabetes. Objectives: The present study was designed to assess the inhibitory potential of ethanol extract of banana flower (EF) on mammalian α-glucosidases and its pharmacological effects on postprandial hyperglycaemia in normal and alloxan-induced diabetic rats. Materials and Methods: EF was evaluated for its inhibitory potential and mode of inhibition on mammalian α-glucosidases. Further, the role of EF and its constituents Umbelliferone (C1) and Lupeol (C2) on glucose uptake using isolated rat hemi-diaphragm and insulinotropic activity using RINm5F (rat insulinoma) cell lines were determined. The phytocomponents in EF were also evaluated using GC-MS. Results: EF illustrated a dose-dependent inhibition for rat intestinal sucrase, maltase and p-nitrophenyl-α-D-glucopyranoside (pNPG) hydrolysis (IC50 values: 18.76±0.22, 25.54±0.10 and 76.42±1.12 μg/ml, respectively) and the mode of inhibition was non-competitive with low Ki values. Oral administration (100-200 mg/kg b.wt.) of EF significantly improved the maltose/glucose-induced postprandial hyperglycaemia in normal and alloxan-induced diabetic rats. EF, C1 and C2 exhibited stimulation of glucose uptake and a dose-dependent glucose-induced insulin secretion at both 4.5 and 16.7 mM glucose concentrations. Further, GC-MS analysis revealed significant levels of steroids (25.61%), diazoprogesterone (21.31%), sesquiterpene (11.78%) and other phytocomponents. Conclusion: EF inhibited α-glucosidases besides promoting glucose uptake and insulin secretion, resulting in antihyperglycaemic effect determining EF as a potent anti-diabetic agent. Abbreviations used: mg/dl: milligramsper deciliter, mM: millimolar, b.wt.: body weight.