The balance between economic development and environmental damage is also evident in the problem of pollution and waste management. Increased economic activity, mainly in industrial countries, has ...

Green synthesis: Photocatalytic degradation of textile dyes using metal and metal oxide nanoparticles-latest trends and advancements

Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra–red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT)-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN)6]4−/[Fe(CN)6]3− redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm2) > GCE/MWCNT (270 mA/cm2) > GCE (80 mA/cm2) > GCE/CA-Ag (7.93 mA/cm2). The silver nanoparticles were evaluated for their antibacterial properties against Gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa) and Gram positive (Bacillus subtilis and Staphylococcus aureus) pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate). Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to that of the leaf extract and ascorbic acid. The nanoparticles were better DPPH scavengers compared to the leaf extract and their antioxidant properties compared favorably the antioxidant results of ascorbic acid. The green approach to nanoparticles synthesis carried out in this research work is simple, non-polluting, inexpensive and non-hazardous.

https://www.mdpi.com/1420-3049/22/5/701/pdf

Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties.

The development of an eco-friendly process for the synthesis of nanoparticles is an important and emerging area in the field of nanotechnology. Silver nanoparticles (AgNPs) were synthesized using Saccharina japonica extract and their cytotoxicity to cervical carcinoma cells was examined. The AgNPs were characterized by ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and selected area electron diffraction. The biosynthesized AgNPs were spherical in shape, and HeLa cells exposed to these NPs showed morphological changes, including rounding and loss of adherence. Fluorescence and confocal laser scanning microscopy revealed the characteristic apoptotic features such as reduction in nuclear volume and cytoplasm condensation.

Green Synthesis: In-vitro Anticancer Activity of Silver Nanoparticles on Human Cervical Cancer Cells

Green synthesis of silver nanoparticles using Hagenia abyssinica (Bruce) J.F. Gmel plant leaf extract and their antibacterial and anti-oxidant activities

Androgenesis is a form of uniparental reproduction leading to progenies inheriting only the paternal set of chromosomes. It has been achieved with variable success in a number of freshwater species and can be attained by artificial fertilization of genetically inactivated eggs following exposure to gamma (γ), X-ray or UV irradiation (haploid androgenesis) and by restoration of diploidy by suppression of mitosis using a pressure or thermal shock. The conditions for the genetic inactivation of the maternal genome in the European sea bass (Dicentrarchus labrax L.) were explored using different combinations of UV irradiation levels and durations. UV treatments significantly affected embryo survival and generated a wide range of developmental abnormalities. Despite the wide range of UV doses tested (from 7.2 to 720 mJ x cm(-2)), only one dose (60 mJ x cm(-2) x min(-1) with 1 min irradiation) resulted in a small percentage (14%) of haploid larvae at hatching in the initial trials as verified by flow cytometry. Microsatellite marker analyses of three further batches of larvae produced by using this UV treatment showed a majority of larvae with variable levels of paternal and maternal contributions and only one larva displaying pure paternal inheritance. The results are discussed also in the context of an assessment of the UV-absorbance characteristics of egg extracts in this species that revealed the presence of gadusol, a compound structurally related to mycosporine-like amino acids (MAAs) with known UV-screening properties.

/pdf/genetic-inactivation-of-european-sea-bass-dicentrarchus-2vm0pq0c8l.pdf

Genetic inactivation of European sea bass (Dicentrarchus labrax L.) eggs using UV-irradiation: observations and perspectives.

The aim of this study was to optimize the biosynthesis of silver nanoparticles using leaves ofAegle marmelos as the primary source. The optimal reaction medium comprised 2:1 concentration of leaf extract and 6mM concentration of silver nitrate solution (pH 7. The biosynthesized silver nanoparticles were confirmed by UV-Vis spectroscopy at 420 nm, XRD and FTIR analysis. The antimicrobial properties of silver nanoparticles were confirmed withBacillus subtilis andPseudomonas aeruginosa.

/pdf/optimization-of-parameters-for-biosynthesis-of-silver-o5s3q99s86.pdf

Optimization of Parameters for Biosynthesis of Silver Nanoparticles Using Leaf Extract of Aegle marmelos

In recent years, numerous research outcomes were established on various naturally occurring compounds that have been shown to have beneficial antioxidant and other biological activities. Antioxidant defence mechanism plays a vital role in combating various diseases mainly due to oxidative stress. However, various models have been utilized to identify their bioactivities using these compounds (quercetin, gallic acid and curcumin). Their toxicity level also has to be explored to determine the threshold levels on the usage of these compounds. In this study, we investigated the lethal concentration of these compounds and abnormalities, biochemical and morphological changes in zebrafish embryo (Danio rerio). Toxicity level was evaluated by calculating the LD50 on the embryonic stages at 24, 48 and 72 h. Antioxidant parameters such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and biological assays such as lipid peroxidation, protein estimation were performed. Microscopic evaluations were also observed to find out morphological abnormalities. However, these naturally derived compounds are reported to have their protective and curative role in many health complications. From the above assays, we are studying the effect of the drugs in both biochemical and molecular way in the zebrafish model organism.

/pdf/toxicity-and-selective-biochemical-assessment-of-quercetin-3norrdtmsu.pdf

Toxicity and Selective Biochemical Assessment of Quercetin, Gallic Acid, and Curcumin in Zebrafish.

This study reports the results on induced meiotic diploid gynogenesis and female homogametic nature in the Indian catfish, Heteropneustes fossilis. The eggs of H. fossilis were inseminated with conspecific sperm. The sperm suspension was diluted to 1 × 107 sperm mL−1 in Hanks balanced salt solution. Sperm were irradiated under UV light, with the exposure time ranging from 15 to 360 s (7500 ergs mm−2 for 60 s). The genetic inactivation of paternal chromosomes was confirmed by chromosome counting from the larval cells and the larvae also had a characteristic haploid syndrome. A typical ‘Hertwig effect’ in the yield of hatched larvae was observed with doses of UV exposure >75 s (9375 ergs mm2). Larvae resulting from sperm UV irradiated above 120 s (15 000 ergs mm2) were 100% haploids. Application of heat shock to the activated eggs was effective in suppressing the release of the second polar body (meiotic gynogenesis) and resulted in diploid gynogenetic larvae morphologically identical to those of the control. The best yield of diploid gynogens (49.3% with respect to the control) was found to be at 6 min after egg activation and the heat shock at 41 °C for a 1-min duration, at an ambient water temperature of 27 °C. A total of 113 diploid gynogenetic fry from seven different female fish were reared and subjected to sexing. All gynogenetic fish were female in contrast to the control, which had a mean sex ratio of 56.7% females (which was not significantly different from 50% female). From these results, the sex determination mechanism in H. fossilis was presumed to be female homogamety.

Induction of meiotic gynogenesis in the stinging catfish Heteropneustes fossilis (Bloch) and evidence for female homogamety.

Chemotherapeutic drugs are a known factor that impairs the system of life due to their severe side effects. A more worrying fact is that the patients administered with doxorubicin fall under the risk of cardiotoxicity. The evolution of exploring plant-derived compounds is a possible way to combat health issues in therapeutic applications. Hence, this study focuses on the protective effect of plant-based compound nuciferine (NFN) against doxorubicin-induced cardiotoxicity in both in vitro and in vivo models. In this investigation, nuciferine significantly reduces DOX-mediated cardiotoxicity by mitigating reactive oxygen species, thereby preventing DNA fragmentation, regulating apoptosis genes and reducing the caspase 3/7 levels in vitro. Besides, nuciferine has shown significant protection against DOX-induced cardiac impairment and the upregulation of cardiogenic markers in vivo. The DOX-induced oxidative stress can be mitigated via enhancing the endogenous antioxidants, thereby controlling ROS-mediated apoptosis. In virtue of these potential features, nuciferine can be a budding candidate to address therapeutic needs.

Nuciferine Attenuates Doxorubicin-Induced Cardiotoxicity: An In Vitro and In Vivo Study.

The optimum UV irradiation duration for the complete inactivation of Heteropneustes fossilis egg’s nucleus was developed. The unfertilized eggs were suspended in Hanks’ balanced salt solution and were irradiated with UV light from both the dorsal and the ventral side for different exposure times ranging from 20 to 200 s (2,500 to 25,000 ergs/mm2). Egg viability was assessed for the different exposure durations at fertilization, hatching, and haploidy. Majority of the larvae derived from irradiated eggs had an abnormal appearance. Complete inactivation of maternal genome was evaluated by haploid chromosome number and morphology which also exhibited haploid syndrome. Successful genome inactivation occurred from 100 s onwards. Larvae resulting from eggs irradiated above 12,500 ergs/mm2 were 100% haploid, with better hatching (81.59%). The genetic inactivation of maternal chromosomes was confirmed by the chromosome count of the resulting embryo (n = 29). Completely anuclear embryos were obtained when the eggs were exposed with UV irradiation between 12,500 and 25,000 ergs/mm2. We conclude that the optimum UV dosage for the complete genetic inactivation of the egg nucleus requires more than 12,500 ergs/mm2.

/pdf/optimization-of-uv-treatment-to-induce-haploid-androgenesis-56fox8xp6y.pdf

Johnsamuel Godwin Christopher

Papers

Optimization of Parameters for Biosynthesis of Silver Nanoparticles Using Leaf Extract of Aegle marmelos

Toxicity and Selective Biochemical Assessment of Quercetin, Gallic Acid, and Curcumin in Zebrafish.

Induction of meiotic gynogenesis in the stinging catfish Heteropneustes fossilis (Bloch) and evidence for female homogamety.

Nuciferine Attenuates Doxorubicin-Induced Cardiotoxicity: An In Vitro and In Vivo Study.

Optimization of UV treatment to induce haploid androgenesis in the stinging catfish, Heteropneustes fossilis