Anti-fouling potential and in-silico analysis of carotenoid and fatty acids from Rauvolfia tetraphylla L.

Study investigated the antifouling potential ofRauvolfia tetraphyllaL. fruit, leaf and stem extracts against the marine fouling organisms throughin-vitroand in-silicoapproach. Methanolic crude extract of R. tetraphylla L.leaf exhibited maximum antibacterial potential against six fouling organisms isolated from Parangipettai coast and was further taken up for column fractionation. Twenty-four fractions were obtained, among which five fractions showed inhibitory efficiency against microfoulers of Bacillus megaterium. The active compounds present in the bioactive fraction were identified by FTIR, GC-MS and NMR (13C; 1H). The bioactive compounds that exhibited maximum antifouling activity were identified as Lycopersene (80%), Hexadecanoic acid; 1, 2-Benzenedicarboxylic acid, dioctyl ester; Heptadecene - (8) - carbonic acid - (1) and Oleic acid. Molecular docking studies of the potent anti-fouling compounds Lycopersene, Hexadecanoic acid, 1, 2-Benzenedicarboxylic acid, dioctyl ester and Oleic acid showed the binding energy of 6.6, - 3.8, -5.3 and -5.9 (Kcal/mol) and hence these compounds will act as a potential biocide to control the aquatic foulers. Moreover, further studies need to carry out in terms of toxicity, field assessment and clinical trial in order to take these biocides for a patent.

New perception about the use of nanofungicides in sustainable agriculture practices.

Protecting plants from pathogens using synthetic nanofungicides is not very effective, because it is harmful to the environment. However, it is synthetic fungicides that farmers are familiar with and commonly use. In this modern era, nanotechnology offers a smart solution to environmental issues at the nanoscale level. It is an emergent field and nanoparticles can be synthesized through various methods. Nanofungicides are efficient due to their solubility and permeability, low dose-dependent toxicity, low dose, enhanced bioavailability, targeted delivery, enhanced bioavailability, and controlled release. There are many metallic compounds, such as Cu, Zn, Ag, and TiO2 available which are used as nanofungicides. There is a contrary relationship between the size of the nanoparticles and their efficacy and antifungal potential. This review article offers a wide knowledge about formulation of nanomaterials as nanofungicides and their role in disease management in plants.

Biosynthesis of Silica Nanoparticles Using the Leaf Extract of Punica granatum and Assessment of Its Antibacterial Activities Against Human Pathogens.

Plant-mediated nanoparticle synthesis is a revolutionary technique with numerous applications in fields, such as agriculture, food processing, and medicine. This study reports that Punica granatum leaf extract is capable of the green and eco-friendly synthesis of silica nanoparticles that provides a simple, cost-effective, and efficient methodology. P. granatum leaf extract was employed as a capping and stabilizing agent for the formation of silica nanoparticles, which were synthesized by a biological method using tetra ethyl ortho silicate. Biosynthesized silica nanoparticles are characterized by X-ray diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. All the analyses and characterization determined that the particles were spherical in shape and amorphous in nature with an average size of 12 nm. P. granatum-assisted silica nanoparticles were tested for antibacterial activity by a well-diffusion method against two-gram negative bacterial pathogens (E. coli and Salmonella sp.). The antibacterial studies prove that P. granatum-assisted silica nanoparticles have good antibacterial properties. These studies will help us find a new nano-drug or medicine against multidrug-resistant bacteria.

Bio-fabrication of Bio-inspired Silica Nanomaterials from Bryophyllum pinnatum Leaf for Agricultural Applications.

A green chemistry approach was employed to synthesize silica nanoparticles (SiNPs) using aqueous extract of Bryophyllum pinnatum leaf as capping agents. The novelty of this study was to produce silica nanoparticles using the biological method. An analysis of the physicochemical properties of formed nanoparticles was successfully completed through sophisticated characterization methods, such as UV-Visible absorbance spectroscopy, Fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, zeta potential analysis, and thermo-gravimetric analysis. All the characterization results indicated their spherical morphology and amorphous nature with an average size of 24 nm. FT-IR results highlighted the key bioactive compounds that could be responsible for capping and reducing the formation of SiNPs. Synthesized SiNPs show excellent stability with a negative zeta potential value of - 32 mV. The biomolecules from B. pinnatum were successfully working for the formation of Si NPs with spherical shapes. Moreover, to assess the agricultural application, green-synthesized SiNPs were carried out by seed germination assay on Vigna radiata. The seed germination assay confirms that a low concentration of SiNPs enhances seed germination. Meanwhile, a higher concentration of the SiNPs inhibits seed germination and shoot, and root formation. SiNPs at optimum concentration could be used in the agriculture field as nano growth promoters.

Elicitor-Induced Metabolomics Analysis of Halodule pinifolia Suspension Culture for an Alternative Antifungal Screening Approach against Candida albicans.

Elicitors are the agents that stimulate the defense responses of plants, and accumulate specialized metabolites in plant tissue culture. This study investigated the elicitor-feeding response of H. pinifolia suspension cell cultures (SCC) for metabolomics analysis and screening of specialized compounds against Candida albicans. Methyl jasmonate (MeJA) was used as an elicitor, and treatment of SCC at a concentration of 20 µM MeJA resulted in the maximum rosmarinic acid (RA) accumulation (117 mg/g dry weight), with transcript levels of RA biosynthetic genes HpPAL, HpC4H, and Hp4CL being 4.2, 2.5, and 3.7-fold higher, respectively, than the controls. GC-MS-based metabolomics analysis revealed a total of 47 metabolites, including 30 organic acids, six amino acids, six flavonoids, two sugars, two plant growth regulators, and one vitamin, which were significantly different between control and MeJA-treated cells. Furthermore, five phenolic acids were discovered at higher concentrations, including p-anisic acid, p-coumaric acid, caffeic acid, vanillic acid, and rosmarinic acid, and were purified and structurally elucidated for alternative antifungal screening against C. albicans and the evaluation of ADMET properties. The results from antifungal screening revealed that RA at MIC of 31.25 mg/L exhibited the lowest growth percentage of C. albicans (1.99%), with higher inhibition of isocitrate lyase 1 (ICL 1) enzyme (93.1%), followed by p-anisic acid (86.2%) and caffeic acid (85.1%), respectively. The drug likeliness and ADMET properties of RA exhibited promising results, with a bioactivity score of 0.57, 0.15, and 0.24 for nuclear receptor ligand, protease inhibitor, and enzyme inhibitor, respectively. Therefore, MeJA appears to have a significant effect on enhanced RA accumulation in H. pinifoia cells with phenylpropanoid transcript expression, and acts as an ICL1 inhibitor of C. albicans.

Chlorophyll fluorescence, dark respiration and metabolomic analysis of Halodule pinifolia reveal potential heat responsive metabolites and biochemical pathways under ocean warming.

Seagrasses are submerged marine angiosperms often prone to various biotic and abiotic stress factors in the marine environment. Our study investigated the response, adaptation and underlying tolerance mechanism of tropical seagrass Halodule pinifolia upon temperature stress (24°, 29°, 37°, and 45 °C) and evaluated the effect of temperature stress on net photosynthesis (ΔF/F'm) and dark respiration (Fv/Fm). In this study, metabolomic analysis of seagrass H. pinifolia upon heat stress has been performed using GC-MS based omics approach. As a result, the net photosynthetic efficiency (ΔF/F'm) was found significantly decreased upon heat stress, while the dark respiration rate was increased to 2.903 mg O2/g FW h-1 and 3.87 mg O2/g FW h-1 as compared to the control (24 °C), respectively. Metabolomic analysis showed heat stress could cause large metabolite variations with respect to sugar, amino acids and organic acids. Interestingly, three thermo-protective metabolites such as trehalose (sugar), glycine betaine (amino acid) and methyl vinyl ketone (organic acid) were profiled from H. pinifolia (45 °C) and is the first report on the occurrence of glycine betaine and methyl vinyl ketone from seagrasses and other aquatic species so far. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated H. pinifolia exposed to heat stress lead to intense biochemical changes and caused significant variations in the heat responsive metabolic pathways. The present findings would facilitate the further research on identifying gene to metabolite networks for an effective management of seagrass conservation by genetic manipulation.

Halodule pinifolia (Seagrass) attenuated lipopolysaccharide-, carrageenan-, and crystal-induced secretion of pro-inflammatory cytokines: mechanism and chemistry.

OBJECTIVES: The study aimed to explore the anti-inflammatory effect, underlying mechanism, and chemistry of Halodule pinifolia extract. METHODS: The ethyl acetate (EHP) and methanol (MHP) extracts of Halodule pinifolia were screened for pro-inflammatory cytokine inhibition effect under various in vitro (LPSand crystal-induced inflammation) and in vivo models (LPS-induced endotoxaemia model, carrageenan-induced paw oedema model, and oxalate-induced renal nephropathy model of inflammation). The effect of EHP on the expression of inflammatory markers using western blot analysis (in vitro) was investigated. Chemical constituents of bioactive EHP were isolated through chromatography and characterised using NMR spectroscopy. Furthermore, EHP was standardised for rosmarinic acid, vanillic acid, and ethyl protocatechuate using HPLC. Also, total phytosterols, phenolic, and flavonoid content of EHP were determined by UV spectroscopy. KEY FINDINGS: EHP was comparatively more effective than MHP in inhibiting cytokines secretions under LPS-induced in vitro models. Furthermore, EHP was screened under endotoxaemia in vivo model, EHP (250 mg/kg) reduced plasma IL-6, TNF-α, and IL-1ß levels by 88.3%, 78.2%, and 74.5%, respectively. In the carrageenan-induced oedema model, EHP (200 mg/kg) reduced paw volume and release of TNF-α (69.3%) and IL-1ß (43.1%). EHP (200 mg/kg) further controlled renal nephropathy by inhibiting plasma IL-1ß and BUN levels. Also, a significant reduction of mRNA expressions of TNF-α and IL-1ß and KIM-1 in renal tissues was observed. Through western blot, EHP was identified to regulate the expression of pro-form as well as mature-form of IL-1ß and caspase-1. EHP constituted rosmarinic acid (RA), vanillic acid (VA), ethyl protocatechuate (EP), sitosterol, stigmasterol, campesterol, and dihydrobrassicasterol. It was determined that 4.6 mg/g of RA, 2.92 mg/g of VA, 0.76 mg/g of EP, 21.7 mg/g of total phenolics, 29.8 mg/g of total flavonoids, and 48.2 mg/g of total phytosterols were present in dry EHP. The presence of anti-inflammatory constituents such as RA, VA, and PE in EHP corroborated the in vitro and in vivo anti-inflammatory activity of EHP. CONCLUSION: The anti-inflammatory property of EHP and its action through attenuation of pan-cytokines suggest that it can be developed into an oral pharmaceutical drug.

Seagrass Halodule pinifolia active constituent 4-methoxybenzioic acid (4-MBA) inhibits quorum sensing mediated virulence production of Pseudomonas aeruginosa.

Biofilm associated, multidrug resistant Pseudomonas aeruginosa infection remain a challenging problem in the clinical field since the conventional antibiotic therapy are largely inefficient and new approaches are needed. Inactivating the QS virulence mechanism with anti-infective agent is an attractive approach to prevent bacterial infections without resistance development. Seagrass Halodule pinifolia (Miki) Hartog has been shown to exhibit potential antimicrobial activities against harmful pathogens. Our study investigated the effects of seagrass H. pinifolia leaf extract and its bioactive constituents on QS-mediated virulence factors and biofilm formation in P. aerugonasa PAO1. Preliminary screening on antibiofilm activity showed that the methanolic extract of H. pinifolia exhibited potential inhibition of biofilm formation (96%) as compared to the control respectively. Further, the potential extract was column fractionated and the active fraction was characterized by GC-MS. In total eight active compounds (protocatacheuic acid (69.3%), rosmarinic acid (63.5%), caffeic acid (59.18%), p-coumaric acid (59.08%), 4-methoxybenzoic acid (53.19%), naringenin (52.9%), vanillic acid (49.19%), 4-hydroxybenzoic acid (41.73%)) were profiled from fraction 2 and were purified by HPLC, structurally confirmed by NMR. Among the eight compounds studied, 4-methoxybenzoic acid (4-MBA) showed an effective inhibition of bacterial growth and was considered as a lead molecule with minimum inhibitory concentration (MIC) of 62.5 µg/mL. Further the effect of 4-MBA on QS mediated virulence factors demonstrated that the compound at MIC concentration reduced the virulence factor production such as elastase (87.5%), protease (79.38%), pyocyanin (91.46%), rhamnolipid (86%), alginate (86%), chitinase (55%), exopolysaccharide production (83.72%) and CSH (78.39%) over the control respectively. Moreover, 4-MBA down regulated the QS-mediated virulence transcript levels upon treatment with 4-MBA. The present findings suggests that seagrasses may act as a newer source for the marine based drug discovery and the lead compound 4-MBA derived from H. pinifolia may act as anti-infective agent against P. aeruginosa as it controls the QS-mediated virulence production.

Two new host records of the cymothoid isopods from Rameswaram Island, southeast coast of India.

Cymothoid isopods are parasitic crustaceans that are considered as a potential threat to the health of different fish species, which eventually lead to economic loss to the fisherman's society. For the first time, cymothoid isopods Nerocila sundaica and Nerocila poruvae infested on the two new host fish species viz., Eleutheronema tetradactylum and Setipinna taty, which were collected from Rameswaram Island, Southeast coast of India. Being an ectoparasite, N. sundaica was found attached on the gill chamber of E. tetradactylum, while N. poruvae was attached on the body surface of S. taty. The standard length 10-250 cm body mass was established for the new host species, and the parasitologic indexes were calculated.