A STUDY ON ANTIOXIDANT AND ANTI-AGING PROPERTIES OF FEW MEDICINAL PLANTS

Objective: The present study was undertaken to appraise the antioxidant and antiaging properties of some important medicinal plants like Syzygium cumini L. (Jamun, the Indian Blackberry), Tinospora cordifolia L. (Giloy) and Trigonella foenum-graecum L. (Methi).Methods: The methanolic extracts of these plants were prepared, incubated with Pheochromocytoma (PC-12) cells and total antioxidant potential of these plants was determined by 2, 2-diphenylpicrylhydrazyl (DPPH) and Ferric reducing ability of plasma (FRAP) assay. Lipid peroxidation assay was also performed to compare the free radical generating potential of these plants. Lipofuscin estimation was done in methanolic extracts of these plants to check which extract can reduce the lipofuscin accumulation in cells which is an anti-aging parameter.Results: The highest inhibition of DPPH radical and ferric reducing ability (FRAP assay) was observed in methanolic extract of Syzygium cumini leaves followed by Trigonella foenum-graecum leaves and lowest inhibition was shown by Tinospora cordifolia leaf extracts. Lipid peroxidation assay done by determining the amount of Malondialdehyde(MDA) formed and highest levels of MDA was produced by Tinospora cordifolia leaf extracts followed by Trigonella foenum-graecum leaf extracts and lowest values were obtained were from Syzygium cumini leaf extracts. The anti-aging parameter which is a determination of lipofuscin pigments in PC-12 cells treated with methanolic extracts of different plants was also examined. Highest accumulation of lipofuscin pigment was observed in cells treated with Tinospora cordifolia leaf extracts followed by Trigonella foenum-graecum leaf extracts and lowest values were obtained were from Syzygium cumini leaf extracts.Conclusion: The results of these findings revealed that the plants which have highest antioxidant potential could be a potent source of anti-aging drugs.Â

Nitric oxide production occurs downstream of reactive oxygen species in guard cells during stomatal closure induced by chitosan in abaxial epidermis of Pisum sativum

The effects of chitosan (β-1,4 linked glucosamine, a fungal elicitor), on the patterns of stomatal movement and signaling components were studied. cPTIO (NO scavenger), sodium tungstate (nitrate reductase inhibitor) or l-NAME (NO synthase inhibitor) restricted the chitosan induced stomatal closure, demonstrating that NO is an essential factor. Similarly, catalase (H2O2 scavenger) or DPI [NAD(P)H oxidase inhibitor] and BAPTA-AM or BAPTA (calcium chelators) prevented chitosan induced stomatal closure, suggesting that reactive oxygen species (ROS) and calcium were involved during such response. Monitoring the NO and ROS production in guard cells by fluorescent probes (DAF-2DA and H2DCFDA) indicated that on exposure to chitosan, the levels of NO rose after only 10 min, while those of ROS increased already by 5 min. cPTIO or sodium tungstate or l-NAME prevented the rise in NO levels but did not restrict the ROS production. In contrast, catalase or DPI restricted the chitosan-induced production of both ROS and NO in guard cells. The calcium chelators, BAPTA-AM or BAPTA, did not have a significant effect on the chitosan induced rise in NO or ROS. We propose that the production of NO is an important signaling component and participates downstream of ROS production. The effects of chitosan strike a marked similarity with those of ABA or MJ on guard cells and indicate the convergence of their signal transduction pathways leading to stomatal closure

Effect of nominal doping of Ag and Ni on the crystalline structure and photo-catalytic properties of mesoporous titania

Doping at nanoscale and modification of nanocrystal either by binding or interaction is possible if the morphology of the nanocrystal and the properties of the dopant present in the chemical solution are exactly known [30,31]. In other words, the binding energy of the impurity/dopant with respect to the surface of the host lattice, the bonding character and the coordination environment have role to affect the microstructure, grain boundary distribution, surface, optical and photo-catalytic properties of doped materials. In view of this,weadopted a modified sol–gel technique, where dopants (Ag and Ni) are present in the chemical solution for the effective doping in the host matrix. However, the literature reports generally involves higher doping concentrations of these ions, but the novelty of the present work lies in the case specific study of a single and nominal doping concentrations of 0.02 wt.% Ag and Ni in TiO2, which has led to unusual changes with respect to its microstructure, grain boundary distribution, pore size distribution and surface properties, optical and photo-catalytic activity towards complete degradation of organic pollutant dye within few minutes of visible and UV light irradiation