Studies on α-glucosidase, aldose reductase and glycation inhibitory properties of sesquiterpenes and flavonoids of Zingiber zerumbet Smith.

Eight known phytochemicals, four sesquiterpenes and four flavonoids of Zingiber zerumbet were screened against α-glucosidase enzyme, aldose reductase enzyme and antiglycation property under in vitro conditions. The results established kaempferol-3-O-methylether as a potent inhibitor of α-glucosidase enzyme with an IC50 value of 7.88 µM. In aldose reductase enzyme inhibition assay, all the compounds except zerumbone epoxide showed good to excellent inhibition properties. Among these, the flavonoid compounds were found to be potent aldose reductase inhibitors compared with the four sesquiterpenes. In addition, compounds such as α-humulene, kaempferol, kaempferol-3-O-methylether and 3″,4″-O-diacetylafzelin displayed potent antiglycation properties. From overall results, we found that kaempferol and kaempferol-3-O-methylether are potent inhibitors of α-glucosidase enzyme, aldose reductase enzyme and glycation reaction, the three main targets of drugs for the treatment of diabetes and its complications.

Nutraceutical potential of Aerva lanata (L.) Juss. ex Schult ameliorates secondary complications in streptozotocin-induced diabetic rats.

Nutraceuticals provide health benefits beyond their basic nutrition by modulating a number of biochemical pathways. They are derived from natural products and have gained recognition worldwide as an adjuvant or therapy in the treatment of metabolic disorders such as diabetes. Although the regulation of blood glucose with drugs and insulin greatly reduces the incidence of secondary complications, the need for long-term treatment raises issues of tolerance and affordability. Therefore, the aim of the present study is to explore the nutraceutical potential of Aerva lanata, a herb widely used for its culinary and therapeutic potential in streptozotocin (STZ)-induced diabetic rats. Treatment with 70% ethanolic extract (ALE) at 500 mg per kg b.w per day for 21 days significantly improved the fasting blood glucose (120.33 ± 1.99 mg dL(-1)), insulin level (9.81 ± 0.38 mU L(-1)), HbA1c (7.3 ± 0.36%) and glycogen content in the liver (35.33 ± 1.38 mg g(-1) protein) and muscle (7.67 ± 0.11 mg g(-1) protein) compared to diabetic controls. The extract also showed a significant decrease in blood glucose by 47.29% towards the end of 2 h in oral glucose tolerance test on Day 21. Its therapeutic potential could be partly attributable to the presence of flavonoids, tannins and terpenes (alpha amyrin, betulin and beta sitosterol) along with micronutrients such as potassium, magnesium, calcium and zinc. Hence, we suggest the suitability of Aerva lanata as a nutraceutical for diabetic patients.

Synthesis, characterization and evaluation of the antioxidant potential of vanadium encapsulated guar gum nanoparticles.

The present study investigated the antioxidant potential of guar gum macroparticles (GGMs), vanadium oxide sulphate (VS) encapsulated guar gum macroparticles (GVMs), guar gum nanoparticles (GGNs), VS encapsulated guar gum nanoparticles (GVNs) and VS. GGNs and GVNs prepared by nanoprecipitation were characterized by SEM (scanning electron microscopy), TEM (transmission electron microscopy) and particle size analysis to confirm the nanostructure of the particles. Particle size analysis revealed that GVNs possess a size of 239 nm, about 148 nm larger than that of GGNs. TEM imaging and EDAX data also confirmed the formation of fine spherical nanoparticles with vanadium incorporation. In addition the larger size of GVNs also confirmed the vanadium incorporation. MTT assay showed that concentrations up to 100 nM of GVNs for 24 h exposure did not induce significant toxicity when VS was toxic (16%) at 100 nM. Various in vitro antioxidant assays (total reducing power, total antioxidant capacity, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hydroxyl radical and superoxide anion radical scavenging assays) revealed significantly high antioxidant potential of GVNs compared to GGNs, VS, GGMs and GVMs. The IC50 of GVNs was 23.21 ± 2.1 µg mL(-1), 33.0 ± 2.93 µg mL(-1), 21 ± 1.98 µg mL(-1) and 22.79 ± 2.12 µg mL(-1) for DPPH, ABTS, hydroxyl, superoxide anion scavenging activity assays respectively. The cell line based assay also proved that the GVN was more effective in reactive oxygen species (ROS) scavenging than VS against tertiary butyl hydrogen peroxide (TBHP) induced oxidative stress in H9c2 cell lines. The overall results indicated that vanadium in combination with nano guar gum exhibits significantly high antioxidant potential.