Efficacy of Antimicrobial and Larvicidal Activities of Green Synthesized Silver Nanoparticles Using Leaf Extract of Plumbago auriculata Lam.

This work reports the synthesis of silver nanoparticles (AgNPs) using aqueous extract of Plumbago auriculata, and evaluates their antibacterial and larvicidal activities. The synthesized silver nanoparticles were characterized by various spectroscopy techniques, such as FTIR, XRD, TEM, EDX, Zeta potential, and DLS. The synthesized AgNPs exhibited significant antibacterial activity against Gram-positive and Gram-negative bacteria, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. Furthermore, synthesized nanoparticles inhibited the fourth instars larvae of Aedes aegypti and Culex quinquefasciatus at the concentration of 45.1 and 41.1 µg/mL respectively. Results of dose-dependent studies showed that synthesized nanoparticles were also effective at low concentrations. Molecular docking studies performed with the salivary protein and odorant-binding protein of Aedes aegypti and Culex quinquefasciatus demonstrated that the naphthoquinone compound plumbagin exhibited reliable binding affinity towards the two enzymes. The findings thus reveal that the plant extract and its nanoparticles can be a better alternative to available chemicals to control mosquitos.

Beneficial effects of mangiferin isolated from Salacia chinensis on biochemical and hematological parameters in rats with streptozotocin-induced diabetes.

Salacia chinensis L. is a traditional Southeast Asian herbal medicine and used in the treatment of diabetes. To investigate the antidiabetic properties of mangiferin from Salacia chinensis and its beneficial effect on toxicological and hematological parameters in streptozotocin induced diabetic rats. Mangiferin was orally treated with the dose of 40 mg/kg body weight/day for 30 days to diabetic rats. Biochemical (blood glucose, uric acid, urea and creatinine), toxicological (AST, ALT and ALP) and hematological parameters (red and white blood cells) and their functional indices were evaluated in diabetic treated groups with mangiferin and glibenclamide. Mangiferin treated diabetic rats significantly (p<0.05) lowered the level of blood glucose, in addition, altered the levels of biochemical parameters including urea, uric acid, and creatinine. Toxicological parameters including AST, ALT and ALP were also significantly reduced after treatment with mangiferin in diabetic rats. Similarly, the levels of red blood, white blood cells and their functional indices were significantly improved through the administration of mangiferin. Thus, our results indicate that mangiferin present in S. chinensis possesses antidiabetic properties and nontoxic nature against chemically induced diabetic rats. Further experimental investigations are warrant to make use of its relevant therapeutic effect to substantiate its ethno-medicinal usage.

Protective nature of mangiferin on oxidative stress and antioxidant status in tissues of streptozotocin-induced diabetic rats.

Oxidative stress plays an important role in the progression of diabetes complications. The aim of the present study was to investigate the beneficial effect of oral administration of mangiferin in streptozotocin (STZ)-induced diabetic rats by measuring the oxidative indicators in liver and kidney as well as the ameliorative properties. Administration of mangiferin to diabetic rats significantly decreased blood glucose and increased plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were significantly (P < 0.05) decreased while increases in the levels of lipidperoxidation (LPO) markers were observed in liver and kidney tissues of diabetic control rats as compared to normal control rats. Oral treatment with mangiferin (40 mg/kg b.wt/day) for a period of 30 days showed significant ameliorative effects on all the biochemical and oxidative parameters studied. Diabetic rats treated with mangiferin restored almost normal architecture of liver and kidney tissues, which was confirmed by histopathological examination. These results indicated that mangiferin has potential ameliorative effects in addition to its antidiabetic effect in experimentally induced diabetic rats.

Mangiferin from Salacia chinensis prevents oxidative stress and protects pancreatic ß-cells in streptozotocin-induced diabetic rats.

Oxidative stress in diabetic tissues is a consequence of free radical accumulation with concurrently impaired natural antioxidants status and results in oxidative tissue damage. The present study investigated the protective effects of mangiferin against pancreatic ß-cell damage and on the antioxidant defense systems in streptozotocin (STZ)-induced diabetic rats. Diabetes was experimentally induced by a single intraperitoneal injection of STZ. Oxidative stress biomarkers such as tissue malondialdehyde, hydroperoxides, reduced glutathione (GSH) content, and nonenzymatic antioxidants were measured. Biochemical observations were further substantiated with histological examination and ultrastructural studies in the pancreas of diabetic, glibenclamide and mangiferin-treated diabetic rats (dosage of 40 mg/kg body weight daily for 30 days). Oral administration of mangiferin and glibenclamide to diabetic rats significantly decreased the level of blood glucose and increased levels of insulin. Additionally, mangiferin treatment significantly modulated the pancreatic nonenzymatic antioxidants status (vitamin C, vitamin E, ceruloplasmin, and reduced GSH content) and other oxidative stress biomarkers. The histoarchitecture of diabetic rats showed degenerated pancreas with lower ß-cell counts, but mangiferin treatment effectively regenerated insulin secreting islet cells. The electron microscopic study revealed damaged nuclear envelope and mitochondria and fewer secretory granules in pancreas of diabetic rats; however, mangiferin treatment nearly normalized pancreatic architecture. The present findings suggest that mangiferin treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and protecting against pancreatic ß-cell damage, which may be attributable to its antioxidative properties.

In Vitro Antioxidant and Anticancer potential of Bark of Costus pictus D.DON

Objective: To evaluate the antioxidant and anticancer potential of different fractions of bark of Costus pictus using various in vitro antioxidant assay systems. Methods: In this study, assay like DPPH radical, superoxide anion radical scavenging activity, nitric oxide scavenging activity, hydrogen peroxide scavenging activity, metal chelating activity and reducing power were used. The concentrations of total phenolic and flavonoids were also calculated for the extracts.Result:pictus. This study suggested that, among the three fractions, the chloroform fraction possesses high antioxidant activity which might be helpful in preventing or slowing the progress of various oxidative stress related disorders. Moreover, all fractions possess potent anticancer properties against colon cancer cells of HT29 and lung carcinoma cells of A549. Conclusions: It can be concluded that the extract of the bark of C. pictus has potential natural antioxidant and this can be used in food industries. There are few reports on the antioxidant capacity of bark of C. pictus and the mechanism of different fractions of bark of C. pictus as antioxidative agents is still not fully understood. Hence further research is underway to analyse and isolate the active compounds responsible for the antioxidant and anticancer activity of different fractions of the bark of C.pictus. The present study elucidated for the first time the antioxidant property of bark of C.

"Phytochemical screening and ""in-vitro"" anti-oxidant activity of methanolic root extract of Erythrina indica"

Objective: Erythrina indica belongs to the family Leguminoseae and it is a medium-sized, spiny, deciduous tree normally growing up to 6-9 m tall. It is also known as “Indian coral tree” or “Tiger’s clow” or “variegated coral tree” or “Kalyana murungai” or “ Mulmurukku” (in Tamil). It is a native of costal forest communities from East Africa, through southeast to Australia. In India, it is distributed in coast forests from Bombay to Malabar . The objective of this study is to explore the phytochemistry and the antioxidant potential of methanolic root extract of Erythrina indica which is considered traditionally as an important medicinal plant. Methods: The preliminary phytochemical analysis was done to find out the presence of various bioactive compounds. In vitro antioxidant analysis of methanolic root extract was performed by 1,1diphenyl, 2 picryl hydrazyl assay, nitric oxide assay, superoxide dismutase assay, ferric reducing antioxidant power assay. Results: The methanolic root extract showed the presence of various phytoconstituents such as flavonoids, tannins, terpenoids, saponins, coumarins and carbohydrates. Besides it also possess strong antioxidant activity. Conclusions: It was concluded that Erythrina indica root possessed a wide range of pharmacologically important phytoconstituents which exhibited strong antioxidant activity.

Effect of mangiferin isolated from Salacia chinensis regulates the kidney carbohydrate metabolism in streptozotocin-induced diabetic rats

Objective: The present investigation was to evaluate the possible anti-diabetic effect of mangiferin from Salacia chinensis (S. chinensis) on the activities of kidney carbohydrate metabolic enzymes in chemically induced diabetic rats. Methods: Diabetes was induced by streptozotocin (STZ) in adult male rats, as a single intraperitoneal injection at a dose of 55 mg/kg body weight. The STZ-induced diabetic rats were treated by mangiferin and glibenclamide (positive control drug) for 30 days. At the end of the experiment, the rats were sacrificed and carbohydrate metabolic enzyme activities were analyzed in the kidney. Results: Diabetic control rats showed a significant increase in the level of fasting blood glucose and also increase the activities of carbohydrate metabolic enzymes in kidney on successive days of the experiment as compared with their basal values. Daily oral administration of mangiferin showed a significant decrease in the blood glucose when compared to diabetic control. The anti-hyperglycemic effect was obtained with the dose of 40 mg/kg b.wt. In addition, treatment of mangiferin shows alteration in kidney carbohydrate metabolic enzymes including gluconeogenic enzymes like glucose-6-phosphatase and fructose-1,6-disphosphatase. These results were comparable with positive control drug, glibenclamide. Conclusions: The results obtained in this study provide evidence of the anti-diabetic potential of mangiferin, mediated through the regulation of carbohydrate key metabolic enzyme activities.