Delaying of cataract through intervention of Hemidesmus indicus in STZ induced diabetic rats.

Hemidesmus indicus (L.) R. Br. was extensively used as hypoglycaemic agent and significance of this plant on secondary complications of diabetes remained unknown. The present study was to investigate the anti-cataractous activity of H. indicus against streptozotocin (STZ)-induced diabetic cataract in rodent model. Root extracts have been prepared and tested for inhibition of rat lens aldose reductase (AR) activity. In addition, its pharmacological potential has been investigated in STZ-induced diabetic cataract. Methanol extract of H. indicus-inhibited AR activity in vitro decreased the blood glucose levels, inhibited the AR activity and delayed the onset and progression of cataract in a dose-dependent manner in in vivo and the antioxidant markers have been normalised. Our results demonstrate that H. indicus has decrease the osmotic stress by inhibiting the AR activity and prevented the loss of antioxidants and delayed the progression of diabetic cataract in STZ-induced diabetic rats.

Mitochondrial signatures for identification of grouper species from Indian waters.

Groupers are important commercial fish in many parts of the world. Accurate identification is critical for effective conservation assessment and fisheries management. Genetic barcodes provide a simple and reproducible method for the identification of species even in the absence of taxonomic expertise. The generation of reference barcodes from properly identified specimens is an important first step in this direction. Here, 36 species belonging to the subfamily Epinephelinae (Family: Serranidae) were collected from landings on the west coast of India and Port Blair, Andaman, and partial nucleotide sequence data of the mitochondrial cytochrome C oxidase subunit I (COI) gene was generated. Barcodes for 13 species were developed from Indian waters for the first time. Analysis using the COI gene produced phylogenetic trees in concurrence with other multi-gene studies. Epinephelus fasciatus and E. areolatus were found to be a species complex, as hypothesized in other studies. The DNA barcodes developed in the study can be used for identifying species within Epinehelinae, where taxonomic ambiguity still exists.

Kallman Syndrome.

Kallman syndrome (KS) is a rare genetic disorder characterized clinically by failure to attain puberty or failure to fully complete it along with an absent or impaired sense of smell with absence of bilateral olfactory bulbi and sulci alongwith absent olfactory tracts. Only very few cases of Kallman syndrome have been reported in females in Indian population.

Oxidation reactions of thymol: a pulse radiolysis and theoretical study.

The reactions of (•)OH and O(•-), with thymol, a monoterpene phenol and an antioxidant, were studied by pulse radiolysis technique and DFT calculations at B3LYP/6-31+G(d,p) level of theory. Thymol was found to efficiently scavenge OH radicals (k = 8.1 × 10(9) dm(3) mol(-1) s(-1)) to produce reducing adduct radicals, with an absorption maximum at 330 nm and oxidizing phenoxyl radicals, with absorption maxima at 390 and 410 nm. A major part of these adduct radicals was found to undergo water elimination, leading to phenoxyl radicals, and the process was catalyzed by OH(-) (or Na(2)HPO(4)). The rate of reaction of O(•-) with thymol was found to be comparatively low (k = 1.1 × 10(9) dm(3) mol(-1) s(-1)), producing H abstracted species of thymol as well as phenoxyl radicals. Further, these phenoxyl radicals of thymol were found to be repaired by ascorbate (k = 2.1 × 10(8) dm(3) mol(-1) s(-1)). To support the interpretation of the experimental results, DFT calculations were carried out. The transients (both adducts and H abstracted species) have been optimized in gas phase at B3LYP/6-31+G(d,p) level of calculation. The relative energy values and thermodynamic stability suggests that the ortho adduct (C6_OH adduct) to be most stable in the reaction of thymol with OH radicals, which favors the water elimination. However, theoretical calculations showed that C4 atom in thymol (para position) can also be the reaction center as it is the main contributor of HOMO. The absorption maxima (λ(max)) calculated from time-dependent density functional theory (TDDFT) for these transient species were close to those obtained experimentally. Finally, the redox potential value of thymol(•)/thymol couple (0.98 V vs NHE) obtained by cyclic voltammetry is less than those of physiologically important oxidants, which reveals the antioxidant capacity of thymol, by scavenging these oxidants. The repair of the phenoxyl radicals of thymol with ascorbate together with the redox potential value makes it a potent antioxidant with minimum pro-oxidant effects.

Antioxidant activity and free radical scavenging reactions of gentisic acid: in-vitro and pulse radiolysis studies.

Abstract Antioxidant activity of gentisic acid has been studied using fast chemical kinetics and two in vitro models, namely the isolated rat liver mitochondria (RLM) and the human erythrocytes. The presence of gentisic acid (GA) during irradiation significantly reduced the levels of gamma radiation induced damages to lipids and proteins in RLM. Further, GA imparted protection to the human erythrocytes against exposure to gamma radiation. Molecular mechanism of free radical scavenging reactions has been evaluated with the help of rate constants and transients obtained from gentisic acid using pulse radiolysis technique. GA efficiently scavenged hydroxyl radical (k = 1.1 × 10(10) dm(3)mol(-1)s(-1)) to produce reducing adduct radical (~76%) and oxidizing phenoxyl radical (~24%). GA has also scavenged organohaloperoxyl radical (k = 9.3 × 10(7) dm(3) mol(-1)s(-1)). Ascorbate has been found to repair phenoxyl radical of GA (k = 1.0 × 10(7) dm(3)mol(-1)s(-1)). Redox potential value of GA(•)/GA couple (0.774 V vs NHE) obtained by cyclic voltammetry is less than those of physiologically important oxidants, which supports the observed antioxidant capacity of GA. We, therefore, propose that the antioxidant and radioprotective properties of GA are exerted by its phenoxyl group.