Biocontrol Agents Induce Disease Resistance in Phyllanthus niruri Linn against Damping-Off Disease Caused by Rhizoctonia solani

Five isolates each of Trichoderma viride and Pseudomonas fluorescens and four isolates of Bacillus subtilis were evaluated for their ability to control Rhizoctonia solani, the causal agent of damping off of Phyllanthus niruri. Among the isolates tested, TVUV10 (T. viride), PFMMP (P. fluorescens) and BSG3 (B. subtilis) showed maximum in vitro inhibition of mycelial growth of R. solani. Isolate PFMMP was also very effective in reducing disease incidence in greenhouse conditions. The effective isolates were evaluated for their ability to induce defense reactions in P. niruri plants. Earlier and increased activity of phenylalanine ammonia lyase, peroxidase, polyphenoloxidase and total phenolics were observed in the biocontrol-agent pretreated P. niruri plants challenged with R. solani. Isolate PFMMP caused early and increased synthesis of all defense related enzymes and total phenol. The present study showed that isolates TVUV10, PFMMP and BSG3 of T. viride, P. fluorescens and B. subtilis respectively are good candidates for the control of R. solani in P. niruri

Enhanced Dispersion of TiO2 Nanoparticles in a TiO2/PEDOT:PSS Hybrid Nanocomposite via Plasma-Liquid Interactions

A facile method to synthesize a TiO2/PEDOT:PSS hybrid nanocomposite material in aqueous solution through direct current (DC) plasma processing at atmospheric pressure and room temperature has been demonstrated. The dispersion of the TiO2 nanoparticles is enhanced and TiO2/polymer hybrid nanoparticles with a distinct core shell structure have been obtained. Increased electrical conductivity was observed for the plasma treated TiO2/PEDOT:PSS nanocomposite. The improvement in nanocomposite properties is due to the enhanced dispersion and stability in liquid polymer of microplasma treated TiO2 nanoparticles. Both plasma induced surface charge and nanoparticle surface termination with specific plasma chemical species are proposed to provide an enhanced barrier to nanoparticle agglomeration and promote nanoparticle-polymer binding

ANTI-DIABETIC EFFECT OF GREEN SYNTHESISED SILVER NANOPARTICLES OF PIPER BETLE

Objective: The objective of the current study is toward the green synthesis of silver nanoparticles from the aqueous leaf extracts of Piper betle (BL) and to evaluate its anti-diabetic efficacy. Methods: Silver nanoparticles were prepared with the aqueous leaf extract of Piper betle. Characterization of silver nanoparticles prepared from extracts of Piper betle was done by UV-Visible spectrophotometer absorbance spectrum; Scanning Electron Microscope; and Fourier transform infrared spectrophotometer. The anti-diabetic efficacy was ascertained by inhibition assay of α-amylase activity and glucose diffusion inhibitory study with aqueous leaf extract of Piper betle and silver nanoparticles of Piper betle (BLNP). Results: Based on the findings of spectrophotometer studies, it was confirmed that the silver nanoparticles were generated. High-density silver nanoparticles were synthesized by Piper betle was depicted by scanning electron microscope. The plant extracts (BLE) and its nanoformulation (BLNP) showed a constructive impact on controlling the glucose level by the inhibition of α-amylase activity and glucose diffusion. Conclusion: It was concluded that the Piper betle can be employed as alternative medicine in the efficient management of Diabetes Mellitus

Epigallocatechin gallate & curcumin prevent transforming growth factor beta 1-induced epithelial to mesenchymal transition in ARPE-19 cells

Background & objectives: Proliferative vitreoretinopathy (PVR) is characterized by the presence of epiretinal membrane (ERM), which exerts traction and detaches the retina. Epithelial to mesenchymal transition (EMT) of the retinal pigment epithelial (RPE) cells underlies ERM formation. Adjuvant therapies aimed at preventing recurrence of PVR after surgery mostly failed in clinical trials. This study was aimed to evaluate the anti-EMT properties of bio-active compounds epigallocatechin gallate (EGCG), curcumin and lycopene as inhibitors of EMT induced by transforming growth factor beta 1 (TGF-β1) in cultured ARPE-19 cells. Methods: ARPE-19 cells were treated with TGF-β1 alone or co-treated with EGCG (1-50 μM), lycopene (1-10 μM) and curcumin (1-10 μM). The mRNA and protein expression of EMT markers, alpha-smooth muscle actin, vimentin, zonula occludens-1 and matrix metalloproteinase-2 (MMP-2), were assessed by reverse transcription polymerase chain reaction/quantitative polymerase chain reaction and immunofluorescence/enzyme linked immunosorbent assay. Activity of MMP-2 was assessed by zymography. Functional implications of EMT were assessed by proliferation assay (MTT assay) and migration assay (scratch assay). Western-blot for phosphorylated Smad-3 and total Smad-3 was done to delineate the mechanism. Results: EGCG and curcumin at 10 μM concentration reversed EMT, inhibited proliferation and migration through Smad-3 phosphorylation, when induced by TGF-β1 in ARPE-19 cells. Lycopene did not prevent EMT in ARPE-19 cells. Interpretation & conclusions: EGCG and curcumin are potent in preventing EMT induced by TGF-β1 in ARPE-19 cells and therefore, proposed as potential molecules for further pre-clinical evaluation in PVR management

Estimation of hydrogen sulphide in the human lymphocytes

179-182Hydrogen sulphide (H₂S), a signaling gasotransmitter and a potent vasorelaxant is endogenously produced by the enzymes cystathionine-β-synthase (CBS) and cystathionine-ϒ-lyase (CSE). CBS is a predominant source of H₂S in the central nervous system, while CSE is the major H₂S producing enzyme in the brain and other nervous tissues. Though the expression of these enzymes in the blood lymphocytes is known, H₂S formation in the lymphocytes has not been reported so far. In the present study, H₂S levels in the lymphocytes of healthy control subjects were estimated, after suitable modifications in a routine method [Stipanuk M H & Beck P W (1982) Biochem J 206, 267-277] used for detecting tissue levels of H₂S. In this method, homocysteine (Hcys) due to its higher solubility was used as the substrate in place of L-cysteine and NaOH was used in place of zinc acetate to increase the entrapment of H₂S in the central well. A mean H₂S level of 11.64 ± 6.36 µM/min/mg protein was detected in the lymphocytes of 8 subjects (mean age, 24 ± 2; 2 male, 6 female). The modified method was found to be more sensitive for H₂S estimation in human lymphocytes. As endogenous H₂S is reported to be involved in the pathogenesis of various cardiovascular and pulmonary diseases, the levels of H₂S in lymphocytes can be a marker of the endogenous tissue levels

Positively and negatively charged magneto excitons in GaAs/Ga

Binding energies of positively and negatively charged magneto excitons are investigated by using the variational procedure within the single band effective mass approximation. A linear Rashba spin-orbit coupling module with the position dependent electron is included in our calculations in order to study the change in spin-orbit splitting energy. In continuation, the interband optical transition, with and without the exciton, is computed as a function of well width. The valence-band anisotropy is included in our theoretical model by using different hole masses in different spatial directions. It is observed that (i) negative trions are found to have a higher binding energy than positive trions, (ii) the exciton binding energy and the interband emission energy both increase when the well width is decreased and (iii) the effect of exciton has influence on the interband emission energy. The results of the present investigation are found to be in good agreement with the recently published results

Antidiabetic effect of free amino acids supplementation in human visceral adipocytes through adiponectin-dependent mechanism

Background & objectives: Amino acids are general nutrients having anti-diabetic property. The present study was undertaken to investigate the mechanism of anti-diabetic effects of amino acids in human visceral adipocyte cells in high glucose environment. Methods: Experiments were carried out in human visceral adipocytes. Adiponectin (APN) siRNAs were designed using Ambion tools. APN mRNA expression was quantified using real-time polymerase chain reaction, and protein level was studied using ELISA. AMP-activated kinase (AMPK) activity was measured and glucose uptake by 2-deoxyglucose uptake method. Results: Amino acids (proline and phenylalanine) exposure to adipocytes significantly (P <0.01) increased APN mRNA by 1.5-folds when compared to control whereas proline increased APN secretion by 10.6-folds (P <0.01), phenylalanine by 12.7-folds (P <0.001) and alanine by 6.3-folds (P <0.01). Free amino acid-induced AMPK activity and glucose uptake were decreased with the transient knockdown of APN. Interpretation & conclusions: Antidiabetic effect of the tested amino acids was exhibited by increased glucose uptake through the AMPK pathway by an APN-dependent mechanism in human visceral adipocytes. This should be tested and confirmed in in vivo system. Newer treatment modalities with amino acids which can enhance glucose uptake and APN secretion can be developed as drug for treating both diabetes and obesity

Biochemistry of homocysteine in health and diseases

275-283The amino acid homocysteine (Hcy), formed from methionine has profound importance in health and diseases. In normal circumstances, it is converted to cysteine and partly remethylated to methionine with the help of vit B12 and folate. However, when normal metabolism is disturbed, due to deficiency of cystathionine-b-synthase, which requires vit B6 for activation, Hcy is accumulated in the blood with an increase of methionine, resulting into mental retardation (homocystinuria type I). A decrease of cysteine may cause eye diseases, due to decrease in the synthesis of glutathione (antioxidant). In homocystinurias type II, III and IV, there is accumulation of Hcy, but a decrease of methionine, thus, there is no mental retardation. Homocysteinemia is found in Marfan syndrome, some cases of type I diabetes and is also linked to smoking and has genetic basis too. In hyperhomocysteinemias (HHcys), clinical manifestations are mental retardation and seizures (type I only), ectopia lentis, secondary glaucoma, optic atrophy, retinal detachment, skeletal abnormalities, osteoporosis, vascular changes, neurological dysfunction and psychiatric symptoms. Thrombotic and cardiovascular diseases may also be encountered. The harmful effects of homocysteinemias are due to (i) production of oxidants (reactive oxygen species) generated during oxidation of Hcy to homocystine and disulphides in the blood. These could oxidize membrane lipids and proteins, (ii) Hcy can react with proteins with their thiols and form disulphides (thiolation), (iii) it can also be converted to highly reactive thiolactone which could react with the proteins forming -NH-CO- adducts, thus affecting the body proteins and enzymes. Homocystinuria type I is very rare (1 in 12 lakhs only) and is treated with supplementation of vit B6 and cystine. Others are more common and are treated with folate, vit B12 and in selected cases as in methionine synthase deficiency, methionine, avoiding excess. In this review, the role of elevated Hcy levels in cardiovascular, ocular, neurologial and other diseases and the possible therapeutic measures, in addition to the molecular mechanisms involved in deleterious manifestations of homocysteinemia, have been discussed

Synthesis and electrochemical characterization of nano-crystalline LiCoO2 powder by a novel sol-gel thermolysis process for Li-ion batteries

Lithium cobalt oxide (LiCoO,) which is being widely used as cathode material powder was prepared by a novel sol-gel thermolysis process using urea and PVA in pH-2 and pH-5 respectively at a low temperature of 390°C. Thermal study shows that the complete crystallization and/or phase forma-tion of the compound is at 390°C. The XRD analysis confirm that the product obtained at pH—2 has more single phase than the product obtained at pH-5. SEM studies shows that the average grain size of the powder is <1 gm. In order to assess the electrochemical reversibility of the prepared LiCo02, cyclic voltammetry study was carried out by fabr-icating button cell in the configuration of Carbon/ M PPE /LiCo0