Selvaraj Arokiyaraj

rapid green synthesis of silver nanoparticles from Chrysanthemum indicum l and its antibacterial and cytotoxic effects: an in vitro study

The present work reports a simple, cost-effective, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using Chrysanthemum indicum and its antibacterial and cytotoxic effects. The formation of AgNPs was confirmed by color change, and it was further characterized by ultraviolet–visible spectroscopy (435 nm). The phytochemical screening of C. indicum revealed the presence of flavonoids, terpenoids, and glycosides, suggesting that these compounds act as reducing and stabilizing agents. The crystalline nature of the synthesized particles was confirmed by X-ray diffraction, as they exhibited face-centered cubic symmetry. The size and morphology of the particles were characterized by transmission electron microscopy, which showed spherical shapes and sizes that ranged between 37.71–71.99 nm. Energy-dispersive X-ray spectroscopy documented the presence of silver. The antimicrobial effect of the synthesized AgNPs revealed a significant effect against the bacteria Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Additionally, cytotoxic assays showed no toxicity of AgNPs toward 3T3 mouse embryo fibroblast cells (25 μg/mL); hence, these particles were safe to use.

Green synthesis of silver nanoparticles using Rheum palmatum root extract and their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa

Abstract In the present study, silver nanoparticles (AgNPs) were synthesized by using aqueous root extracts of Rheum palmatum and characterized by various spectroscopic methods. The nanoparticles were found to be in hexagonal and spherical shapes. The average particle size was found to be 121 ± 2 nm with zeta potential values of −21.6 mv by dynamic light scattering (DLS) method. Gas chromatography–mass spectrometry (GC-MS) analysis of R. palmatum revealed 35 compounds. The synthesized AgNPs showed significant activity against Staphylococcus aureus and Pseudomonas aeruginosa with IC90 values of 15 μg/ml and IC50 values of 7.5 μg/ml, respectively. The protein leakage level was high and morphological changes occurred in bacteria treated with AgNPs.

In-vitro antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinone isolated from Aegle marmelos (Linn.) Correa

BackgroundPlant metabolites have wide applications and have the potential to cure different diseases caused by microorganisms. The aim of the study was to evaluate the antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinine isolated from Aegle marmelos (Linn.) Correa.MethodsA compound was obtained by eluting the crude extract, using varying concentrations of the solvents by the chromatographic purification. Broth micro dilution method was used to assess the antimicrobial activity and anticancer study was evaluated using MTT assay. Larvicidal activity was studied using leaf disc no-choice method.ResultsBased on the IR, 13C NMR and 1H NMR spectral data, the compounds were identified as quinone related antibiotic. It exhibited significant activity against Gram positive and Gram negative bacteria. The lowest Minimum Inhibitory Concentration (MIC) of the compound against Bacillus subtilis and Staphylococcus aureus was 100 and 75 μg mL-1 respectively. Against Escherichia coli and Pseudomonas aeruginosa it exhibited MIC value of 25 μg mL-1. The MIC of the compound against Aspergillus niger, A. clavatus, Penicillium roqueforti was 20 μg mL-1 and that against Fusarium oxysporum (20 μg mL-1), A. oryzae (40 μg mL-1), and Candida albicans (60 μg mL-1), respectively. It showed effective antibiofilm activity against E. coli, S. typhii and P. aeroginosa at 8 μg mL-1 and did not exhibit considerable cytotoxic activity against Vero and HEP2 cell lines. Additionally, the compound documented significant antifeedant and larvicidal activities against Helicoverpa armigera and Spodoptera litura at 125, 250, 500 and 1000 ppm concentrations.ConclusionThe results concluded that the compound can be evaluated further in industrial applications and also an agent to prepare botanical new pesticide formulations.

Characterization of Ambrette Seed Oil and Its Mode of Action in Bacteria

In the present study, chemical composition and the antibacterial mechanism of ambrette seed oil are investigated. Chemical composition of the oil was analysed by gas chromatography-mass spectrometry (GC-MS). Thirty-five compounds were identified and the major compounds were found to be farnesol acetate (51.45%) and ambrettolide (12.96%). The antibacterial activity was performed by well diffusion assay and the mechanisms were studied by measuring the alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and protein leakage assays. The antibacterial effect of the ambrette seed oil showed inhibitory effect against Bacillus subtilis, Staphylococcus aureus and Enterococcus faecalis. The LDH activity was high in all tested bacteria compared with control, whereas the ALP and protein concentrations were also increased in E. faecalis. Molecular docking revealed the ligands farnesol acetate and ambrettolide had satisfactory binding energy towards the beta lactamase TEM-72 and dihydrofolate reductase (DHFR) protein. Due to its better antibacterial properties, the ambrette seed oil could be used as a source of antibacterial agents.

Effect of rhubarb (Rheum spp.) root on in vitro and in vivo ruminal methane production and a bacterial community analysis based on 16S rRNA sequence

The objective of this study was to evaluate the anti-methanogenic effect of rhubarb (Rheum spp.) on in vitro, in vivo, and bacterial community composition using Quantitative Insights into Microbial Ecology sequencing. Rhubarb root powder was tested at different concentrations (0, 0.33, 0.67, and 1.33 g/L) in vitro, and all incubations were carried out in triplicate two runs on separate days. Concentrations of 0.67 and 1.33 g/L rhubarb significantly (P < 0.05) reduced methane production and the acetate : propionate ratio compared with those of the Control, without adverse effects on total volatile fatty acids and total gas production. In the second in vivo trial, four Hanwoo (Korean native) steers (live bodyweight, 556 ± 46 kg) with a ruminal cannula were housed individually in metabolic stalls and fed a basal diet twice daily in equal amounts at 0900 hours and 2100 hours. The before rhubarb treatment (before treatment) duration was 24 days for all steers; 14 days were used for diet adaptation and 10 days were used for gas samples collected 1, 2, and 3 h after the morning feeding on Days 3, 5, 7, and 9. We used three syringe needles passed through the ruminal cannula stopper at different time points as a simple and rapid method to sample rumen gas. Thereafter, three mesh bags containing 30 g of sliced rhubarb root each were placed at different depths in the rumen of each steer for 14 days (after treatment), and gas samples were collected on Days 4, 7, 10, 12, and 13. The results showed a significant (P < 0.05) decrease in methane concentration from the rhubarb-treated steers and provide the evidence that this method would be useful for in vivo screening of anti-methanogenic feed additives or plant material. Furthermore, 16s RNA sequencing after treatment showed increases in the numbers of Prevotella, and Lactobacillus, but decreases in Methanobrevibacter. In conclusion, rhubarb had an anti-methanogenic effect in vitro and in vivo, and the increase in the number of Prevotella shifted ruminal fermentation towards propionate production.

Hepatoprotective mechanism of lycorine against carbon tetrachloride induced toxicity in swiss albino mice - A proteomic approach

Objective To investigate the differential of protein expression in CCl4 induced mice treated with lycorine.

Effect of Taurine on Prostate-Specific Antigen Level and Migration in Human Prostate Cancer Cells

In Korea, prostate cancer incidence has significantly increased in recent years. Prostate-specific antigen (PSA) is a marker for prostate cancer, and elevated serum PSA levels have been associated with prostate intraepithelial neoplasms. Meanwhile, metastasis is a process by which cancer spreads from the place at which it first arose as a primary tumor to distant locations in the body. The so-called tissue inhibitors of metalloproteinases (TIMPs), which are naturally occurring inhibitors of matrix metalloproteinases (MMPs), play an important role in the complex regulation of MMPs. They inhibit the catalytic activity of MMPs by binding to activated MMPs and control breakdown of extracellular matrix. Thus, the balance between MMPs and TIMPs plays a vital role in maintaining the integrity of healthy tissues, and MMP inhibitors, as well as TIMP activators, are expected to be useful chemotherapeutic agents for the treatment of malignancies. In addition, vascular endothelial growth factor (VEGF) plays an important role in prostate cancer invasion. VEGF is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. In the present study, therefore, we investigated the anti-prostate cancer metastasis effect of taurine, and proved taurine suppressed PSA and several metastasis-related genes in human prostate cancer cells, LNCaP and PC-3. In addition, taurine inhibited migration of LNCaP and PC-3.

Energy Balance and Methane Production of Hanwoo Cows Fed Various Kind of Roughage

This experiment was conducted to determine methane production and emission factors for a range of roughage diets fed to Hanwoo cows at a level of maintenance energy requirement. Seven cows were fed mixed hay only, 12 cows were fed mixed hay containing 30~50% rice straw and 6 cows were fed a mixed hay diet supplemented with 1.0 kg of wheat bran. Each cow was placed in a metabolic crate for 10 consecutive days, including last 7 days for sampling of feces and urine. At the end of the sampling period, the cows were transferred to an open-circuit respiration chamber for 24 consecutive hours. Methane conversion rate (5.5~6.2%, mean value = 5.8%) and emission factor (33.6~38.6 kg/head/year, mean value = 35.2) were not significantly affected by the diets although the mixed hay only diet resulted in 11 and 15% higher respective rates than the other two. However, in light of the many assumptions that forage with good quality might reduce methane production, additional experiments should be required for participation in the greenhouse gas emission trading system. (Key words : Hanwoo cow, Maintenance, Methane emission factor, Roughage sources)

Ruminal methane emissions, metabolic, and microbial profile of Holstein steers fed forage and concentrate, separately or as a total mixed ration

Few studies have examined the effects of feeding total mixed ration (TMR) versus roughage and concentrate separately (SF) on ruminant methane production. Therefore, this study compared differences in methane production, ruminal characteristics, total tract digestibility of nutrients, and rumen microbiome between the two feeding methods in Holstein steers. A total six Holstein steers of initial bodyweights 540 ± 34 kg were divided into two groups and assigned to a same experimental diet with two different feeding systems (TMR or SF) in a crossover design with 21 d periods. The experimental diet contained 73% concentrate and 27% forage and were fed twice a day. The total tract digestibility of crude protein, neutral detergent fibre, and organic matter were not affected by the two different feeding systems. Steers fed TMR emitted more methane (138.5 vs. 118.2 L/d; P < 0.05) and lost more gross energy as methane energy (4.0 vs. 3.5% gross energy intake; P = 0.005) compared to those fed SF. Steers fed TMR had greater (P < 0.05) total volatile fatty acid (VFA), ammonia-N concentrations and propionate proportion of total VFA at 1.5 h, whereas lower after that compared to steers fed SF. The greater (P < 0.05) acetate: propionate ratio at 4.5 h for steers fed TMR reflected the shift of H2 sink from propionate towards acetate synthesis. The lower (P < 0.05) isobutyrate and isovalerate proportions of total VFA observed in steers fed TMR implies decrease in net consumption of H2 for microbial protein synthesis compared to SF. There were no differences in both major bacterial and archaeal diversity between TMR and SF, unlike several minor bacterial abundances. The minor groups such as Coprococcus, Succiniclasticum, Butyrivibrio, and Succinivibrio were associated with the changes in ruminal VFA profiles or methanogenesis indirectly. Overall, these results indicate that SF reduces methane emissions from ruminants and increases propionate proportion of total VFA without affecting total tract digestion compared to TMR. There were no evidences that the response differed due to different major underlying microbial population.