Responses of isolated scale melanophores of a fresh water carp,Cirrhinus mrigala (Ham.) to zidovudine

Zidovudine (AZT) induced concentration related aggregation in C. mrigala melanophores. Denervated melanophores failed to respond to AZT. Specific and nonspecific alpha adrenoceptor antagonists completely blocked the responses of fish melanophores to AZT. Histamine and prostaglandin antagonists also inhibited aggregation of the melanophores induced by AZT. The results suggest that AZT may release a mixture of neurotransmitter like substances, which cause the aggregation of this fish melanophores.     

Role of plant phytochemicals and microbial enzymes in biosynthesis of metallic nanoparticles

Applied Microbiology and Biotechnology - Metal-based nanoparticles have gained tremendous popularity because of their interesting physical, biological, optical, and magnetic properties. These...     

Wound healing applications of biogenic colloidal silver and gold nanoparticles: recent trends and future prospects

Applied Microbiology and Biotechnology - Nanotechnology has emerged as a prominent scientific discipline in the technological revolution of this millennium. The scientific community has focused on...     

Role of green fluorescent proteins and their variants in development of FRET-based sensors

Since the last decade, a lot of advancement has been made to understand biological processes involving complex intracellular pathways. The major challenge faced was monitoring and trafficking of metabolites in real time. Although a range of quantitative and imaging techniques have been developed so far, the discovery of green fluorescent proteins (GFPs) has revolutionized the advancement in the field of metabolomics. GFPs and their variants have enabled researchers to ‘paint’ a wide range of biological molecules. Fluorescence resonance energy transfer (FRET)-based genetically encoded sensors is a promising technology to decipher the real-time monitoring of the cellular events inside living cells. GFPs and their variants, due to their intrinsic fluorescence properties, are extensively being used nowadays in cell-based assays. This review focuses on structure and function of GFP and its derivatives, mechanism emission and their use in the development of FRET-based sensors for metabolites.     

Evidence for presence of GABA-ergic receptor mediated dispersion in isolated scale melanophores of a carp,Cirrhinus mrigala Ham

Effects of GABA-ergic agonists and antagonists were examined on the melanophores of a carp C. mrigala in vitro. GABA and baclofen both induced concentration - related dispersion in fish melanophores. Denervation of the melanophores by reserpine treatment potentiated the sensitivity of the melanophores to GABA. While denervation by cooling treatment inhibited the sensitivity of the melanophores to GABA, atropine, bicuculline and pentylenetetrazole all inhibited the dispersal responses of the melanophores induced by higher concentrations of GABA. 5-aminovaleric acid also significantly inhibited the dispersion of the melanophores induced either by GABA or baclofen. It is concluded that GABA-ergic agonist induced dispersal responses in C mrigala melanophores are mediated through specific GABA receptors. The presence of both GABAA and GABAB receptors in this fish melanophores has been indicated.     

Synthesis and biological evaluation of some novel sulfamoylphenyl-pyridazinone as anti-inflammatory agents (Part-II * )

Seven novel 6-aryl-2-(p-sulfamoylphenyl)-4,5-dihydropyridazin-3(2H)-ones (2a-g) were synthesized by the condensation of appropriate aroylpropionic acid and 4-hydrazinobenzenesulfonamide hydrochloride in ethanol. Structure of all compounds have been elucidated by elemental analysis, IR, (1)H NMR, (13)C NMR, DEPT and MS spectrscopy. These compounds were tested for their anti-inflammatory activity in carrageenan-induced rat paw edema model. Compound 2b exhibited anti-inflammatory activity comparable to that of celecoxib (at 5?h). Two other compounds 2d and 2g showed promising anti-inflammatory activity (edema reduction more than 80% at 5?h). These compounds (2b, 2d and 2g) did not produce any ulceration in gastric region.     

Antioxidant response and proteomic modulations in Indian mustard grown under salt stress

Productivity of Indian mustard (Brassica juncea L. Czern. and Coss.) is markedly reduced by salt stress. To develop salt tolerance in this important oilseed crop is a need of the hour. This study, based on analysis of growth parameters and antioxidant profile of fourteen Indian mustard genotypes treated with 50, 100, 150 and 200 mM of sodium chloride, was performed to identify the salt-sensitive and salt-tolerant genotypes. Salinity stress inhibited biomass accumulation and reduced the protein and chlorophyll contents in a dose-dependent manner. The reduction was the highest in genotype Pusa Agrani and lowest in CS-54, depicting their contrasting sensitivity to salt stress. Salt treatments triggered a concentration-dependent overproduction of reactive-oxygen species and a concurrent upregulation of the expression of different antioxidants. Genotype CS-54 showed the least damage and maintained a high antioxidant level with almost each salt treatment, exhibiting its competence to withstand the damage provoked by salinity stress. Genotype Pusa Agrani, on the contrary, depicted a salt-sensitive nature by way of its very high lipid peroxidation and low intensity of antioxidants. These two genotypes were further investigated through gel-based proteomic approach, which resulted in the identification and quantification of 42 salinity-responsive proteins related to different metabolic modifications. Molecular processes, including photosynthesis, redox homeostasis, nitrogen metabolism, ATP synthesis, protein synthesis and degradation, signal transduction and respiratory pathways, have exhibited significant changes. The identified stress-responsive proteins could pave the way to develop salt tolerance in Indian mustard plant, thus sustaining its productivity under salinity.     

Multifunctional theranostic applications of biocompatible green-synthesized colloidal nanoparticles

Applied Microbiology and Biotechnology - Phytochemicals offer immense promise for sustainable development and production of nanotechnology-enabled products. In the present study, Olax nana Wall. ex...     

Analyzing the responses of saccharin in context with melatonin receptors on the melanophores of the fish Labeo rohita (Ham.)

The hormone melatonin regulates the biological clock and assist in various other physiologies of vertebrates. Present work is intended to check the affinity of saccharin towards the melatonin receptors and the possible role of saccharin interference in the melatonin physiology. The present in vitro study is based on the working model of isolated scale melanophores in the dorso-lateral region of Labeo rohita. The pigment cells were incubated in the agonist and the antagonists within a limited time frame and subsequently their Melanophore Size Index (MSI) were calculated. The inferences were drafted through the observed signal transduction upshots in pigment translocations within the melanophores. Saccharin, in a wide dose range, has consistently induced a concentration-related aggregation similar to the aggregatory effect as shown by melatonin on the melanophores. Binding of saccharin with the receptors and eliciting its aggregatory effect is partially dependent on the release of neurotransmitters. The aggregatory effects were found to be significantly blocked by luzindole, K185, and prazosin, which are the potent melatonin receptor blockers, at the higher concentrations of saccharin. Hence, all the three subtypes of melatonin receptors viz. MT?, MT?, and MT? are participating in saccharin-mediated aggregations. Blocking by neomycin shows that Ca2? ions are very crucial in dispensing the aggregatory effect of the sweetener. This research demands that an intensive and careful thorough study should be made about saccharin, specifically its effects upon melatonin physiology, before its unwarranted use as the food ingredients for human use.     

Study of the effects of the casein derived bitter tastant on the melanophores in milieu with the melatonin receptors

The present study was undertaken to ascertain whether the casein derived bitter tastant Cyclo (Leu-Trp) [CLT] has an affinity or not for the particular receptors of the pineal hormone, melatonin, on the melanophores of a major carp Labeo rohita (Ham.). The bitter tastant CLT, in the dose range of 3.34×10(-16) M to 3.34×10(-4) M, has induced an aggregatory effect but not in a dose dependent manner. Binding of CLT with the receptors may vary at different concentrations. Denervation of the melanophores has shown a complete inhibition of the CLT mediated aggregation. Prazosin has partially inhibited the aggregatory effect of CLT. Moreover, the bitter tastant's response is mediated through the α2 adrenoceptors only at particular dose ranges. The MT1 and MT2 melatonin receptor antagonist luzindole and the MT2 specific antagonist K185 have perfectly blocked the aggregatory effects of CLT. We have found that the CLT mediated aggregatory effect is dependent upon the release of neurotransmitters and the two subtypes of melatonin (MT) receptors (MT1 and MT2) possess a perfect affinity towards the bitter tastant CLT. Our study demands a need to further make a clinical research on the effects of bitter tastants on the physiology of the biological rhythm maintaining hormone melatonin.