Effect of aqueous leaf extract of Azadirachta indica on the reproductive organs in male mice

Effect of oral administration (50, 100, and 200 mg/kg body weight/day, for 28 days) of aqucous leaf extract of neem (Azadirachta indica) on the male reproductive organs of the Parkes (P) strain mice was investigated. The treatment had no effect on body weight and the reproductive organs weight. In treated mice, testes showed both normal and affected seminiferous tubules in the same sections; the affected seminiferous tubules showed intraepithelial vacuolation, loosening of germinal epithelium, marginal condensation of chromatin in round spermatids, occurrence of giant cells, mixing of germ cell types in stages of spermatogenesis and degenerated appearance of germ cells. In severe cases, the tubules were lined with Sertoli cells only, Sertoli cells and rare germ cells, or with Sertoli cells and several germ cells but without cellular association patterns. Also, the frequency of affected seminiferous tubules in testes of the extract-treated mice was significantly higher than the controls, though this remained unaffected in mice treated at 50 mg/kg body weight of the extract. Doses at 50 or 100 mg/kg body weight of neem leaf extract did not cause appreciable alterations in histological appearance of the epididymis, while a dose of 200 mg/kg body weight caused marked alterations both in histological appearance and the level of sialic acid in the duct. The treatment also had adverse effects on motility, morphology, and number of spermatozoa in the cauda epididymidis, level of fructose in the seminal vesicle, and on litter size. After 42 days of withdrawal of the treatment, the alterations induced in the reproductive organs recovered to control levels. Our results suggested that treatment with neem leaf extract caused reversible alterations in the male reproductive organs of P mice.     

Spin trapping of the superoxide anion: complications in the use of the water-soluble nitroso-aromatic reagent DBNBS

Sodium 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) is reported to be a useful spin trap for the measurement of superoxide anions in aqueous solution. However, the signal observed arises from interaction of the spin trap with some species other than the superoxide radical or hydrogen peroxide, a product of its dismutation, as the addition of both superoxide dismutase and catalase to a superoxide generating system failed to attenuate the signal. Therefore caution must be employed in the interpretation of results obtained using this spin trap.     

Determination on the binding of thiadiazole derivative to human serum albumin: a spectroscopy and computational approach

4-[3-acetyl-5-(acetylamino)-2,3-dihydro-1,3,4-thiadiazole-2-yl]phenyl benzoate from the family of thiadiazole derivative has been newly synthesized. It has good anticancer activity as well as antibacterial and less toxic in nature, its binding characteristics are therefore of huge interest for understanding pharmacokinetic mechanism of the drug. The binding of thiadiazole derivative to human serum albumin (HSA) has been investigated by studying its quenching mechanism, binding kinetics and the molecular distance, r between the donor (HSA) and acceptor (thiadiazole derivative) was estimated according to Forster’s theory of non-radiative energy transfer. The Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes of temperature-dependent K_b was calculated, which explains that the reaction is spontaneous and exothermic. The microenvironment of HSA have also been studied using synchronous fluorescence spectroscopy, and the feature of thiadiazole derivative-induced structural changes of HSA have been carried using Fourier transform infrared spectroscopy and the Molecular modelling simulations explore the hydrophobic and hydrogen bonding interactions.     

Phosphorylation of Bcl-2 and Bax Proteins during Hypoxia in Newborn Piglets

Studies indicate that phosphorylated Bcl-2 cannot form a heterodimer with Bax and thus may lose its antiapoptotic potential. The present study tests the hypothesis that graded hypoxia in cerebral tissue induces the phosphorylation of Bcl-2, thus altering the heterodimerization of Bcl-2 with Bax and subsequently leading to apoptosis. Anesthetized, ventilated newborn piglets were assigned to a normoxic and a graded hypoxic group. Cerebral cortical neuronal nuclei were isolated and immunoprecipitated; immune complexes were separated and reacted with Bcl-2 and Bax specific antibodies. The results show an increased level of serine/tyrosine phosphorylated Bcl-2 in nuclear membranes of hypoxic animals. The level of phosphorylated Bcl-2 protein increased linearly with decrease in tissue PCr. The level of phosphorylated Bax in the neuronal nuclear membranes was independent of cerebral tissue PCr. The data shows that during hypoxia, there is increased phosphorylation of Bcl-2, which may prevent its heterodimerization with Bax and lead to increased proapoptotic activity due to excess Bax in the hypoxic brain. Further increased phosphorylation of Bcl-2 may alter the Bcl-2/Bax-dependent antioxidant, lipid peroxidation and pore forming activity, as well as the regulation of intranuclear Ca²⁺ and caspase activation pathways. We speculate that increased phosphorylation of Bcl-2 in neuronal nuclear membranes is a potential mechanism of programmed cell death activation in the hypoxic brain.     

Inhibition of ascorbate autoxidation by a dialyzed,heat-denatured extract of plant tissues

Preparations obtained from various plant sources were analyzed for their effect on the autoxidation of ascorbic acid and norepinephrine. The former reaction was followed by spectro-photometric detection of ascorbic acid at 265 nm, the latter one by measuring the formation of noradrenochrome at 480 nm. Extracts were prepared from $\text{Philodendron}$ leaves and the edible portion and seeds of green peppers ($\text{Capsicum Annuum}$). The tissues were minced, homogenized in 10 volumes of 16 mM Na-phosphate buffer pH 7.4 and centrifuged at 35,000g for 30 min. The supernatant was dialyzed in 12,000 m.w. cut-off tubing, denatured in boiling water and centrifuged at 10,000g for 10min. Aliquots (5–50 ul) of the supernatant were assayed in 5 ml 16 mM Na-phosphate buffer pH 7.4 containing 100 uM ascorbate or norepinephrine. The denatured extracts had marked dose-dependent inhibitory effect on the autoxidation of ascorbic acid, with negligible influence on the formation of noradrenochrome. EDTA inhibited both reactions. The selectiveness of the extract toward the autoxidation of ascorbic acid makes it unlikely that the inhibitory effect is based on sequestering metal-ions.     

Modification of flag leaf senescence and yield characters in barley (Hordeum vulgare L.) by gibberellic acid and kinetin

Barley plants (Hordeum vulgare L.) received foliar applications of 10^?4 M gibberellic acid (GA₃) and Kinetin (KN) individually and in combination at one or more of three growth stages: flag leaf appearance (I), ear emergence (II), and the first stage of senescence initiation in the flag leaf (III). Both plant growth regulators (PGR) hastened onset of senescence when sprayed at Stage I and/or Stage II. Treatment at Stage III, either alone or in combination with treatments at the other stages, tended to postpone senescence. Yield components also showed stage-dependent response: Stage I treatment increased the formation of total and bearing tillers, and Stage III treatment improved grain number and weight. However, while GA₃ proved more effective than KN, the two together acted antagonistically.     

QTL mapping for some grain traits in bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Grain traits are important agronomic attributes with the market value as well as milling yield of bread wheat. In the present study, quantitative trait loci (QTL) regulating grain traits in wheat were identified. Data for grain area size (GAS), grain width (GWid), factor form density (FFD), grain length-width ratio (GLWR), thousand grain weight (TGW), grain perimeter length (GPL) and grain length (GL) were recorded on a recombinant inbred line derived from the cross of NW1014?×?HUW468 at Meerut and Varanasi locations. A linkage map of 55 simple sequence repeat markers for 8 wheat chromosomes was used for QTL analysis by Composite interval mapping. Eighteen QTLs distributed on 8 chromosomes were identified for seven grain traits. Of these, five QTLs for GLWR were found on chromosomes 1A, 6A, 2B, and 7B, three QTLs for GPL were located on chromosomes 4A, 5A and 7B and three QTLs for GAS were mapped on 5D and 7D. Two QTLs were identified on chromosomes 4A and 5A for GL and two QTLs for GWid were identified on chromosomes 7D and 6A. Similarly, two QTLs for FFD were found on chromosomes 1A and 5D. A solitary QTL for TGW was identified on chromosome 2B. For several traits, QTLs were also co-localized on chromosomes 2B, 4A, 5A, 6A, 5D, 7B and 7D. The QTLs detected in the present study may be validated for specific crosses and then used for marker-assisted selection to improve grain quality in bread wheat.     

Effect of berberine and (±)-bicuculline isolated from<Emphasis Type="Italic">Corydalis chaerophylla</Emphasis> on spore germination of some fungi

Berberine and (±)-bicuculline were isolated from roots and leaves, respectively, ofCorydalis chaerophylla. Both were effectivein vitro against spore germination of some plant pathogenic fungi (Alternaria brassicicola, A. brassicae, A. cheiranthi, A. melongenae, A. solani, Colletotrichum musae, C. falcatum, Curvularia penniseti, C. lunata, C. maculans, C. pallescens, Curvularia sp.,Erysiphe pisi, E. cichoracearum, Erysiphe sp.,Fusarium udum, Helminthosporium spiciferum, H. penniseti, H. frumentacei, Heterosporium sp.,Oidium erysiphoides andUstilago cynodontis). Berberine and (±)-bicuculline significantly inhibited spore germination of all the fungi at concentrations of 100–1000 ppm. Berberine was effective against all the fungi at all concentrations; most of the fungi did not germinate at 1000 ppm.H. penniseti conidia did not germinate at any cencentration of (±)-bicuculline.U. cynodontis was the least sensitive fungus at lower concentrations but 800 ppm dose was highly effective.     

The SbMT-2 Gene from a Halophyte Confers Abiotic Stress Tolerance and Modulates ROS Scavenging in Transgenic Tobacco

Heavy metals are common pollutants of the coastal saline area and Salicornia brachiata an extreme halophyte is frequently exposed to various abiotic stresses including heavy metals. The SbMT-2 gene was cloned and transformed to tobacco for the functional validation. Transgenic tobacco lines (L2, L4, L6 and L13) showed significantly enhanced salt (NaCl), osmotic (PEG) and metals (Zn⁺⁺, Cu⁺⁺ and Cd⁺⁺) tolerance compared to WT plants. Transgenic lines did not show any morphological variation and had enhanced growth parameters viz. shoot length, root length, fresh weight and dry weight. High seed germination percentage, chlorophyll content, relative water content, electrolytic leakage and membrane stability index confirmed that transgenic lines performed better under salt (NaCl), osmotic (PEG) and metals (Zn⁺⁺, Cu⁺⁺ and Cd⁺⁺) stress conditions compared to WT plants. Proline, H₂O₂ and lipid peroxidation (MDA) analyses suggested the role of SbMT-2 in cellular homeostasis and H₂O₂ detoxification. Furthermore in vivo localization of H₂O₂ and O₂ ⁻; and elevated expression of key antioxidant enzyme encoding genes, SOD, POD and APX evident the possible role of SbMT-2 in ROS scavenging/detoxification mechanism. Transgenic lines showed accumulation of Cu⁺⁺ and Cd⁺⁺ in root while Zn⁺⁺ in stem under stress condition. Under control (unstressed) condition, Zn⁺⁺ was accumulated more in root but accumulation of Zn⁺⁺ in stem under stress condition suggested that SbMT-2 may involve in the selective translocation of Zn⁺⁺ from root to stem. This observation was further supported by the up-regulation of zinc transporter encoding genes NtZIP1 and NtHMA-A under metal ion stress condition. The study suggested that SbMT-2 modulates ROS scavenging and is a potential candidate to be used for phytoremediation and imparting stress tolerance.