Phytochemical screening, antimicrobial, anti-inflammatory and anti-cancerous activities of ethanol and hexane extracts of Urochloa ramosa

Urochloa ramosa is known for its environmental benefits such as stabilization and reclamation of polluted soils, in agriculture to control root-knot nematodes infecting crops, in medicine to treat cardiovascular diseases, duodenal ulcer, hyperglycemia, nephritis and snake bites. Qualitative analyses of phytochemicals in ethanol and hexane extracts were performed by standard methods. In vitro anti-microbial assay was performed against gram positive bacteria viz., Bacillus subtilis and Staphylococcus aureus, Gram negative bacteria viz., Pseudomonas aeruginosa and Escherichia coli and fungus Candida albicans by disc diffusion method. Hexane extract of Urochloa ramosa was found to be 70% effective against Candida albicans indicating potent antifungal property. In vitro anti-inflammatory activity was performed by albumin denaturation assay, proteinase inhibition activity assay and membrane stabilization assay using various concentrations of extracts with Aspirin and Diclofenac sodium as standard. Heat induced protein denaturation was considerably prevented by ethanol and hexane extract at concentrations between 200-500 µg/ml resulting in 60 and 62% inhibition respectively. Heat induced haemolysis of erythrocyte was remarkably inhibited (59 and 68 % respectively) at concentration of 500 µg/ml. 62 and 65 % Hypotonicity induced haemolysis was also inhibited between concentration of 300-500 µg/ml in both extracts respectively. Inhibition of formation of new blood vessels by Chorioallantoic membrane (CAM) assay proved anti-angiogenic effects of extracts. Purification, characterization and structural elucidation of bioactive molecules present in ethanol and hexane extracts are needed to be explored further for assessment of better biological activites than crude extract

Evaluation of in vitro antioxidant and antidiabetic activities from Amomum nilgiricum leaf extract

In the present study, hexane, ethyl acetate and methanol fraction of Amomum nilgiricum leaf was evaluated for antidiabetic efficacy, scavenging activities, followed by estimation of total phenol, total flavonoids. In the present study, a significant amounts of total phenolics (79.92±1.58 mg/g) and flavonoids (21.74± 0.89 mg/g) were showed from Ethyl acetae fraction. H2O2 scavenging activity (97.62±2.89%) with IC50 value of 78.57 µg/ml concentrations. Ethyl acetate fraction exhibited maximum inhibitory activity of glucose movement into outer solution across dialysis membrane at 250 µg/ml as compared to the control. The ethyl acetate fraction revealed maximum insulin secretory activity (130.5±3.66%) in RIN-m5F cells. Methanol fraction recorded maximum glucose uptake percent in yeast cells (67.08±1.68%) when compared to standard metronidazole (68.06±0.73%). This study scientifically validates the antidiabetic activity of A. nilgiricum. Hence, in view of its comparative hypoglycemic strength, it can work as a valuable healing agent in treating diabetes

Efficacy of indigenous plant growth-promoting rhizobacteria and Trichoderma strains in eliciting resistance against bacterial wilt in a tomato

Bacterial wilt of tomato caused by Ralstonia solanacearum is a serious threat to tomato production worldwide. For eco-friendly management of bacterial wilt of tomato, the rhizospheric microorganisms belonging to the genera Bacillus (6 isolates), Brevibacillus (1 isolate), Pseudomonas (3 isolates), and Trichoderma (8 isolates) were studied for their ability to induce innate immunity in tomato, individually and in combination against R. solanacearum in greenhouse and field studies. In laboratory studies, maximum germination percent of 93%, vigor index of 1609 was noted in seed bacterization with P. fluorescens Pf3, followed by 91% germination, vigor index of 1593 in treatment with T. asperellum T8 over control. Under greenhouse conditions, protection against bacterial wilt in individual treatments with PGPRs ranged from 38 to 43% and Trichoderma sp. ranged from 39 to 43% in comparison to control. In comparison to individual seed treatment, among different combinations, maximum seed germination percent of 97% was recorded with combination P. fluorescens Pf3 + T. longibrachiatumUNS11. In greenhouse studies’ combination seed treatment with P. fluorescens Pf3 + T. longibrachiatumUNS11 offered an impressive 62% protection against bacterial wilt over control. Similarly, under field conditions, seed treatment with P. fluorescens Pf3 + T. longibrachiatumUNS11 resulted in 61% protection. The innate immunity triggered by eco-friendly seed treatment was analyzed by expression to defense-related enzymes such as peroxidase, phenylalanine ammonialyase, and polyphenol oxidase in comparison to control. This study indicated that the potential benefits of using combination treatments of beneficial microorganisms in effectively inducing resistance are possible for dual benefits of enhanced plant growth, tomato yield, and pathogen suppression

Detection and Characterization of Antibacterial Siderophores Secreted by Endophytic Fungi from Cymbidium aloifolium

Endophytic fungi from orchid plants are reported to secrete secondary metabolites which include bioactive antimicrobial siderophores. In this study endophytic fungi capable of secreting siderophores were isolated from Cymbidium aloifolium, a medicinal orchid plant. The isolated extracellular siderophores from orchidaceous fungi act as chelating agents forming soluble complexes with Fe3+. The 60% endophytic fungi of Cymbidium aloifolium produced hydroxamate siderophore on CAS agar. The highest siderophore percentage was 57% in Penicillium chrysogenum (CAL1), 49% in Aspergillus sydowii (CAR12), 46% in Aspergillus terreus (CAR14) by CAS liquid assay. The optimum culture parameters for siderophore production were 30 degrees C, pH 6.5, maltose and ammonium nitrate and the highest resulting siderophore content was 73% in P. chrysogenum. The total protein content of solvent-purified siderophore increased four-fold compared with crude filtrate. The percent Fe3+ scavenged was detected by atomic absorption spectra analysis and the highest scavenging value was 83% by P. chrysogenum. Thin layer chromatography of purified P. chrysogenum siderophore showed a wine-colored spot with R-f value of 0.54. HPLC peaks with R(t)s of 10.5 and 12.5 min were obtained for iron-free and iron-bound P. chrysogenum siderophore, respectively. The iron-free P. chrysogenum siderophore revealed an exact mass-to-charge ratio (m/z) of 400.46 and iron-bound P. chrysogenum siderophore revealed a m/z of 453.35. The solvent-extracted siderophores inhibited the virulent plant pathogens Ralstonia solanacearum, that causes bacterial wilt in groundnut and Xanthomonas oryzae pv. oryzae which causes bacterial blight disease in rice. Thus, bioactive siderophore-producing endophytic P. chrysogenum can be exploited in the form of formulations for development of resistance against other phytopathogens in crop plants

Exogenous priming of chitosan induces upregulation of phytohormones and resistance against cucumber powdery mildew disease is correlated with localized biosynthesis of defense enzymes

In recent years, exploration of biopolymer-based materials to avoid hazardous chemicals in agriculture has gained enormous importance for sustainable crop improvement. In the present study, chitosan a biopolymer derived from crab-shell was used in different concentrations as priming agent to cucumber seeds and were evaluated for its effect to enhance plant growth parameters as well as its ability to induce resistance against powdery mildew disease. Among the treatments, seeds-primed with 2.5 mg/mL exhibited early seedling germination of 90% and vigour of 2665 and also remarkably enhanced the cucumber growth parameters which might be fairly attributed to the stimulation of phytohormones content in primed plants over the controls. More importantly, under greenhouse conditions a significant induced disease protection of 66.6% against powdery mildew disease was noticed in chitosan-pretreated plants at 2.5 mg/mL. The induced resistant plants also showed a significant deposition of lignin, callose and H2O2. Notably, polyphenol oxidase, phenylalanine ammonia-lyase, peroxidase and glucanase defense-responsive enzymes were upregulated in chitosan-primed plants. Considered together, these results determine that the susceptible cucumber cultivar elicits immunity after perception of priming with chitosan to upregulate phytohormones and synthesize defense-responsive enzymes, thereby induce resistance against powdery mildew disease and strengthen the growth-promotion of cucumber plants. (C) 2020 Elsevier B.V. All rights reserved

Efficacy of indigenous plant growth-promoting rhizobacteria and Trichoderma strains in eliciting resistance against bacterial wilt in a tomato

Bacterial wilt of tomato caused byRalstonia solanacearumis a serious threat to tomato production worldwide. For eco-friendly management of bacterial wilt of tomato, the rhizospheric microorganisms belonging to the generaBacillus(6 isolates),Brevibacillus(1 isolate),Pseudomonas(3 isolates), andTrichoderma(8 isolates) were studied for their ability to induce innate immunity in tomato, individually and in combination againstR. solanacearumin greenhouse and field studies. In laboratory studies, maximum germination percent of 93%, vigor index of 1609 was noted in seed bacterization withP. fluorescensPf3, followed by 91% germination, vigor index of 1593 in treatment withT. asperellumT8 over control. Under greenhouse conditions, protection against bacterial wilt in individual treatments with PGPRs ranged from 38 to 43% andTrichodermasp. ranged from 39 to 43% in comparison to control. In comparison to individual seed treatment, among different combinations, maximum seed germination percent of 97% was recorded with combinationP. fluorescensPf3 +T. longibrachiatumUNS11. In greenhouse studies' combination seed treatment withP. fluorescensPf3+ T. longibrachiatumUNS11 offered an impressive 62% protection against bacterial wilt over control. Similarly, under field conditions, seed treatment withP. fluorescensPf3+ T. longibrachiatumUNS11 resulted in 61% protection. The innate immunity triggered by eco-friendly seed treatment was analyzed by expression to defense-related enzymes such as peroxidase, phenylalanine ammonialyase, and polyphenol oxidase in comparison to control. This study indicated that the potential benefits of using combination treatments of beneficial microorganisms in effectively inducing resistance are possible for dual benefits of enhanced plant growth, tomato yield, and pathogen suppression

GC–MS analysis of phytoconstituents from Amomum nilgiricum and molecular docking interactions of bioactive serverogenin acetate with target proteins

Amomum nilgiricum is one of the plant species reported from Western Ghats of India, belonging to the family Zingiberaceae, with ethno-botanical values, and is well-known for their ethno medicinal applications. In the present investigation, ethyl acetate and methanol extracts of A. nilgiricum were analyzed by Fourier transform infrared spectrometer (FTIR) and gas chromatography-mass spectrometry (GC–MS) to identify the important functional groups and phytochemical constituents. The FTIR spectra revealed the occurrence of functional characteristic peaks of aromatic amines, carboxylic acids, ketones, phenols and alkyl halides group from leaf and rhizome extracts. The GC–MS analysis of ethyl acetate and methanol extracts from leaves, and methanol extract from rhizomes of A. nilgiricum detected the presence of 25 phytochemical compounds. Further, the leaf and rhizome extracts of A. nilgiricum showed remarkable antibacterial and antifungal activities at 100 mg/mL. The results of DPPH and ferric reducing antioxidant power assay recorded maximum antioxidant activity in A. nilgiricum methanolic leaf extract. While, ethyl acetate leaf extract exhibited maximum α-amylase inhibition activity, followed by methanolic leaf extract exhibiting aldose reductase inhibition. Subsequently, these 25 identified compounds were analyzed for their bioactivity through in silico molecular docking studies. Results revealed that among the phytochemical compounds identified, serverogenin acetate might have maximum antibacterial, antifungal, antiviral, antioxidant and antidiabetic properties followed by 2,4-dimethyl-1,3-dioxane and (1,3-13C2)propanedioic acid. To our best knowledge, this is the first description on the phytochemical constituents of the leaves and rhizomes of A. nilgiricum, which show pharmacological significance, as there has been no literature available yet on GC–MS and phytochemical studies of this plant species. The in silico molecular docking of serverogenin acetate was also performed to confirm its broad spectrum activities based on the binding interactions with the antibacterial, antifungal, antiviral, antioxidant and antidiabetic target proteins. The results of the present study will create a way for the invention of herbal medicines for several ailments by using A. nilgiricum plants, which may lead to the development of novel drugs

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Eucalyptus globules and Their Fungicidal Ability Against Pathogenic Fungi of Apple Orchards

Eucalyptus globules belonging to the Myrtaceae family was explored for the synthesis of zinc oxide nanoparticles and for biological applications. The aqueous extract of the synthesized zinc nanoparticles (ZnNPs) was characterized using UV-visible spectrophotometer, FTIR, SEM and TEM. The aqueous broth was observed to be an efficient reducing agent, leading to the rapid formation of ZnNPs of varied shapes with sizes ranging between 52-70 nm. In addition, antifungal activity of the biosynthesized ZnNPs was evaluated against major phytopathogens of apple orchards. At 100 ppm of ZnNPs, the fungal growth inhibition rate was found to be 76.7% for Alternaria mali, followed by 65.4 and 55.2% inhibition rate for Botryosphaeria dothidea and Diplodia seriata, respectively. The microscopic observations of the treated fungal plates revealed that ZnNPs damages the topography of the fungal hyphal layers leading to a reduced contraction of hyphae. This considerable fungicidal property of ZnNPs against phytopathogenic fungi can have a tremendous impact on exploitation of ZnNPs for fungal pest management and ensure protection in fruit crops

Antifungal Activity of <i>Eclipta alba</i> Metabolites against Sorghum Pathogens

Unscientific use of synthetic fungicides in plant disease management has environmental ramifications, such as disease resurgence and serious health problems due to their carcinogenicity. This has prompted the identification and development of eco-friendly greener alternatives. Eclipta alba extract was evaluated for its antifungal activity in in vitro and in vivo against sorghum fungal pathogens Fusarium thapsinum, Alternaria alternata, Epicoccum sorghinum, and Curvularia lunata. The column purified methanolic extract of E. alba exhibited good antifungal activity against the target pathogens. The MIC was observed at 80 mg/mL for all tested pathogenic fungi, whereas MFC was 80 mg/mL for E. sorghinum, 100 mg/mL for F. thapsinum, A. alternata, and C. lunata. In vitro germination percentage was significantly high in seeds treated with E. alba extract (98%) over untreated control (91%). Significant disease protection of 95% was observed in greenhouse and 66% disease protection was noticed in field experiments. The efficacy of E. alba extract in field conditions was improved with the use of E. alba extract formulation. The profile of phytochemicals in E. alba methanol fractions was obtained by ultra-performance liquid chromatography (UPLC) mass spectroscopy. The [M-H]&#8722; at m/z 313.3, m/z 797.9, and m/z 269.0 revealed the presence of wedelolactone, eclalbasaponin II, and apigenin, respectively. The H-nuclear magnetic resonance spectroscopy (1H-NMR) chemical shift value supported the findings of the mass spectrometry. The results highlighted the possible use of E. alba methanolic extract as alternative to chemical fungicide in sorghum disease management

Ameliorated Antibacterial and Antioxidant Properties by Trichoderma harzianum Mediated Green Synthesis of Silver Nanoparticles

Biosynthesis of silver nanoparticles using beneficial Trichoderma harzianum is a simple, eco-friendly and cost-effective route. Secondary metabolites secreted by T. harzianum act as capping and reducing agents that can offer constancy and can contribute to biological activity. The present study aimed to synthesize silver nanoparticles using T. harzianum cell filtrate and investigate different bioactive metabolites based on LC-MS/MS analysis. The synthesized silver nanoparticles (AgNPs) from T. harzianum were characterized by ultraviolet–visible spectrophotometry, Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The surface plasmon resonance of synthesized particles formed a peak centered near 438 nm. The DLS study determined the average size of AgNPs to be 21.49 nm. The average size of AgNPs was measured to be 72 nm by SEM. The cubic crystal structure from XRD analysis confirmed the synthesized particles as silver nanoparticles. The AgNPs exhibited remarkable antioxidant properties, as determined by DPPH and ferric reducing antioxidant power (FRAP) assay. The AgNPs also exhibited broad-spectrum antibacterial activity against two Gram-positive bacteria (S. aureus and B. subtilis) and two Gram-negative bacteria (E. coli and R. solanacearum). The minimum inhibitory concentration (MIC) of AgNPs towards bacterial growth was evaluated. The antibacterial activity of AgNPs was further confirmed by fluorescence microscopy and SEM analysis