Population genetic structure of Indian shad, Tenualosa ilisha inferred from variation in mitochondrial DNA sequences.

Indian shad, Tenualosa ilisha, is a commercially important anadromous fish representing major catch in Indo-pacific region. The present study evaluated partial Cytochrome b (Cyt b) gene sequence of mtDNA in T. ilisha for determining genetic variation from Bay of Bengal and Arabian Sea origins. The genomic DNA extracted from T. ilisha samples representing two distant rivers in the Indian subcontinent, the Bhagirathi (lower stretch of Ganges) and the Tapi was analyzed. Sequencing of 307 bp mtDNA Cytochrome b gene fragment revealed the presence of 5 haplotypes, with high haplotype diversity (Hd) of 0.9048 with variance 0.103 and low nucleotide diversity (π) of 0.14301. Three population specific haplotypes were observed in river Ganga and two haplotypes in river Tapi. Neighbour-joining tree based on Cytochrome b gene sequences of T. ilisha showed that population from Bay of Bengal and Arabian Sea origins belonged to two distinct clusters.

Aristololactam-beta-D-glucoside. A new DNA binding monofunctional intercalating alkaloid.

The binding of aristololactam-beta-D-glucoside to DNA is characterized by hypochromism and bathochromism in the absorption band, quenching of the fluorescence intensity, increase in the positive and negative ellipticity of DNA, enhancement of thermal transition temperature, sign and magnitude of thermodynamic parameters, increase of the contour length of sonicated rod-like DNA and induction of the unwinding-rewinding process of covalently closed superhelical DNA. Binding parameters determined from absorbance and fluorescence titration by Scatchard analysis, according to an excluded-site model, indicate a very high affinity towards DNA. The binding of the alkaloid is an exothermic process with Gibbs free energy of -7.4 kcal/mol, van't Hoff enthalpy of -13.8 kcal/mol and entropy of -21.5 cal/degree/mol at 25 degrees. On the basis of these observations it is concluded that aristololactam-beta-D-glucoside binds to DNA by a mechanism of intercalation.

Evaluation of antioxidant effectiveness of a few herbal plants.

We have screened a number of plants from the Indian soil for potential antioxidant properties out of which fifteen extracts were found to be positive. Leaves/bulk from the plants were crushed and extracted with organic solvents by three different ways. The first group of plants were extracted with CHCL3:CH3OH (2:1), evaporated, partitioned between petroleum ether and methanol (9:1), aqueous methanolic part re-partitioned between methanol:H2O (4:1) and dichloromethane. Methanol was evaporated from the aqueous methanolic part and extracted with n-butanol. The second group of plants were extracted with methanol followed by partitioning between petroleum ether and CH3OH. The rest of the extraction procedure was the same as above. A third extraction procedure was used for Ocimum sanctum which after extraction with CHCL3:CH3OH (2:1), partitioned between CCL4 and CH3OH:H2O (9:1). Aqueous methanolic part was repartitioned between CH3OH:H2O (4:1) and CHCl3 and CHCl3 soluble part was used for the study. Free radical scavenging activities of the plant extracts were examined by chemiluminescence method. Peroxyl radical was generated from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), superoxide radical (O2-) from xanthine/xanthine oxidase (XO) and hydroxyl radical (OH) from Xanthine/XO/FeCl3/ EDTA. In addition, O2- and OH. scavenging activities were also determined by cytochrome C reduction and deoxyribose oxidation methods, respectively. The results of this study demonstrate that these plant extracts possess potent antioxidant activities.

The role of antioxidant activity of Phyllanthus emblica fruits on prevention from indomethacin induced gastric ulcer.

Pretreatment with the butanol extract of the water fraction of Phyllanthus emblica fruits at the dose of 100 mg/kg body-weight, orally administered to rats for 10 consecutive days, was found to enhance secretion of gastric mucus and hexosamine (P<0.001) in the indomethacin induced ulceration of rats. The morphological observations also supported a protective effect of the stomach wall from lesion. The indomethacin treatment of the premedicated animals with the drug hardly affected either the malondialdehyde (MDA) or superoxide dismutase (SOD) level in gastric tissue while the ulcerative agent itself significantly enhanced both the levels. An antioxidant property appears to be predominantly responsible for this cytoprotective action of the drug.

A new triterpene ester, an anthraquinone and other constituents of the fern Lygodium flexuosum.

Lygodium flexuosum, a fern reported to exhibit antifertility activity, has been found to contain a new compound characterized as O- P-coumaryl-dryocrassol, besides dryocrassol itself, tectoquinone, kaempferol, kaempferol-3-beta- D-glucoside, beta-sitosterol, and stigmasterol.