Thidiazuron, a phenyl-urea cytokinin, inhibits ergosterol synthesis and attenuates biofilm formation of Candida albicans.

Candida albicans is a common human fungal pathogen that colonizes mucosa and develops biofilm in the oral cavity that causes oral candidiasis. It has been reported that cytochrome P450 enzyme (CYP51), a vital part of the ergosterol synthesis cascade, is associated with Candida infections and its biofilm formation. Thidiazuron, a phenyl-urea cytokinin, exhibits anti-senescence and elicitor activity against fungal infection in plants. However, how Thidiazuron impacts C. albicans biofilm formation is still uncertain. Here, we aimed to investigate the effects of a Thidiazuron against the growth and biofilm formation properties of C. albicans using in silico and in vitro experimental approaches. A preliminary molecular docking study revealed potential interaction between Thidiazuron and amino acid residues of CYP51. Further in vitro antifungal susceptibility test, scanning electron microscopy (SEM) and time kill analysis revealed the anti-fungal activity of Thidiazuron in both dose and time-dependent manner. Crystal violet staining, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay revealed 50% inhibition in C. albicans biofilm by Thidiazuron at concentrations 11 and 19 µM respectively. Acridine orange staining assay visually confirmed the biofilm inhibitory potential of Thidiazuron. The gene expression study showed that Thidiazuron treatment down regulated the expression of genes involved in ergosterol synthesis (ERG3, ERG11, ERG25), cell adhesion (ASL3, EAP1), and hyphae development (EFG1, HWP1, SAP5) in C. albicans. Wherease, the expression of negative transcription regulator of hyphae (NRG1) was upregulated (5.7-fold) by Thidiazuron treatment. Collectively, our data suggest that Thidiazuron is a robust antifungal compound and an outstanding biofilm inhibitor, which may promise further therapeutic development due to CYP51 binding and inhibition of ergosterol formation against C. albicans.

The complete chloroplast genome of Ocimum tenuiflorum L. subtype Krishna Tulsi and its phylogenetic analysis.

The complete chloroplast genome (cp) of Ocimum tenuiflorum L. subtype Krishna Tulsi was sequenced and assembled using Illumina paired-end sequencing data. The cp genome is 151,758 bp in length, including a large single copy (LSC) region of 82,794 bp, a small single-copy region (SSC) of 17,592 bp, and a pair of inverted repeated (IR) region of 25,686 bp. The cp genome of Krishna Tulsi encodes 129 genes, including 90 protein-coding, 31 transfer RNA (tRNA), and eight ribosomal RNA (rRNA) genes. While the overall GC content was 37.9%, it is 36.0%, 31.8%, and 43.1% in the LSC, SSC, and IR regions, respectively. Phylogenetic analysis based on chloroplast genome sequences of 17 species from Lamiaceae revealed that O. tenuiflorum subtype Krishna Tulsi is clustered with other Ocimum species, and forms a clade with genera from family Lamiaceae.

Solvothermal-assisted green synthesis of hybrid Chi-Fe3O4 nanocomposites: a potential antibacterial and antibiofilm material.

In this present study, a hybrid Chi-Fe3O4 was prepared, characterised and evaluated for its antibacterial and antibiofilm potential against Staphylococcus aureus and Staphylococcus marcescens bacterial pathogens. Intense peak around 260 nm in the ultraviolet-visible spectrum specify the formation of magnetite nanoparticles. Spherical-shaped particles with less agglomeration and particle size distribution of 3.78-46.40 nm were observed using transmission electron microscopy analysis and strong interaction of chitosan with the surface of magnetite nanoparticles was studied using field emission scanning microscopy (FESEM). X-ray diffraction analysis exhibited the polycrystalline and spinel structure configuration of the nanocomposite. Presence of Fe and O, C and Cl elements were confirmed using energy dispersive X-ray microanalysis. Fourier transform infrared spectroscopic analysis showed the reduction and formation of Chi-Fe3O4 nanocomposite. The antibacterial activity by deformation of the bacterial cell walls on treatment with Chi-Fe3O4 nanocomposite and its interaction was visualised using FESEM and the antibiofilm activity was determined using antibiofilm assay. In conclusion, this present study shows the green synthesis of Chi-Fe3O4 nanocomposite and evaluation of its antibacterial and antibiofilm potential, proving its significance in medical and biological applications.

Biosynthesis of iron oxide nanoparticles using leaf extract of Ruellia tuberosa: Antimicrobial properties and their applications in photocatalytic degradation.

Green synthesis of nanoparticles is one of the promising, ecofriendly and safer methods. Utilizing plant sources as reducing agents will replace the use of toxic chemicals for nanoparticle synthesis. In the present study FeONPs were synthesized using Ruellia tuberosa (RT) leaf aqueous extract, further characterization of FeONPs was performed using UV-vis spectroscopy analysis showing visible peak at 405 nm. The Fourier transform infrared spectroscopy (FTIR) proved the presence of Fe metallic ions. The structural characteristic using Field emission scanning electron microscopy with energy dispersive x-ray spectroscopy (FESEM-EDX) and Transmission electron microscopy (TEM) analysis revealed hexagonal nanorods with agglomeration. Dynamic light scattering (DLS) calculated the average size of FeONPs around 52.78 nm and differential scanning colorimetry (DSC) proved the stability of FeONPs till higher temperature of 165.52 °C. As an application part, the synthesized FeONPs showed potential antibacterial activity as individual and incorporating material over cotton fabrics against Gram negative and Gram positive pathogens. FeONPs showed higher antibacterial activity against Escherichia coli, Klebsiella pneumoniae and lesser antibacterial activity against Staphylococcus aureus. The photocatalytic ability of the synthesized FeONPs was demonstrated by the degrading crystal violet dye under solar irradiation upto 80%. Thus, FeONPs synthesized using Ruellia tuberosa could play a vital role in killing the bacterial pathogens and degrading dye for the bioremediation of wastewater from industrial and domestic sources.

Synthesis of ecofriendly copper oxide nanoparticles for fabrication over textile fabrics: Characterization of antibacterial activity and dye degradation potential.

Growing concerns over the toxicity of metallic nanoparticles synthesized using physical and chemical techniques seems to be a major hurdle for researchers. Green synthesis of nanoparticles is one of the promising, ecofriendly and safer methods. Utilizing plant sources as reducing agents will replace the use of toxic chemicals for nanoparticle synthesis. Among the various nanoparticles, copper has been theoretically and practically proved for its antimicrobial properties. However, to reduce the risk of copper toxicity, Ruellia tuberosa (R. tuberosa) aqueous extract is used for the synthesis of CuONPs in the present study. Nonetheless, till date no work has been reported on the use of R. tuberosa aqueous extract for the synthesis of CuONPs. In the present study, aqueous extract of R. tuberosa has been used for the synthesis of CuONPs. The synthesis of CuONPs was confirmed by the absorption peak at 327 nm representing the nanorods with an average size of 83.23 nm. Further, the CuONPs revealed antimicrobial effects against clinical pathogens such as Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Embedding CuONPs on cotton fabrics showed bactericidal activity against the bacterial pathogens. In addition, the photocatalytic property of the CuONPs was divulged by their crystal violet (CV) dye degradation potential. Thus, the green synthesized CuONPs using R. tuberosa could provide a remedy against bacterial pathogens in hospital and industrial environments.

Pinocembrin, a novel histidine decarboxylase inhibitor with anti-allergic potential in in vitro.

Pinocembrin (5, 7- dihydroxy flavanone) is the most abundant chiral flavonoid found in propolis, exhibiting antioxidant, antimicrobial and anti-inflammatory properties. However, the effect of Pinocembrin on allergic response is unexplored. Thus, current study aimed at investigating the effects of Pinocembrin on IgE-mediated allergic response in vitro. A special emphasis was directed toward histidine decarboxylase (HDC) and other pro-allergic and pro-inflammatory mediators. Preliminary studies, using a microbiological model of Klebsiella pneumoniae, provided first evidences that suggest Pinocembrin as a potential thermal stable inhibitor for HDC. Applying docking analysis revealed possible interaction between Pinocembrin and mammalian HDC. In vitro studies validated the predicted interaction and showed that Pinocembrin inhibits HDC activity and histamine in IgE-sensitized RBL-2H3 in response to dinitrophenol (DNP)-bovine serum albumin (BSA) stimulation. In addition, Pinocembrin mitigated the damage in the mitochondrial membrane, formation of cytoplasmic granules and degranulation as indicated by lower ß-hexoseaminidase level. Interestingly, it reduced range of pro-inflammatory mediators in the IgE-mediated allergic response including tumor necrosis factor (TNF)-α, interleukin (IL)-6, nitric oxide (NO), inducible NO synthase (iNOS), phosphorylation of inhibitory kappa B (IкB)-α, prostaglandin (PGE)-2 and cyclooxygenase (COX)-2. In conclusion, current study suggests Pinocembrin as a potential HDC inhibitor, and provides the first evidences it is in vitro anti-allergic properties, suggesting Pinocembrin as a new candidate for natural anti-allergic drugs.

Suppressive subtractive hybridization approach revealed differential expression of hypersensitive response and reactive oxygen species production genes in tea (Camellia sinensis (L.) O. Kuntze) leaves during Pestalotiopsis thea infection.

Tea (Camellia sinensis (L.) O. Kuntze) is an economically important plant cultivated for its leaves. Infection of Pestalotiopsis theae in leaves causes gray blight disease and enormous loss to the tea industry. We used suppressive subtractive hybridization (SSH) technique to unravel the differential gene expression pattern during gray blight disease development in tea. Complementary DNA from P. theae-infected and uninfected leaves of disease tolerant cultivar UPASI-10 was used as tester and driver populations respectively. Subtraction efficiency was confirmed by comparing abundance of ß-actin gene. A total of 377 and 720 clones with insert size >250 bp from forward and reverse library respectively were sequenced and analyzed. Basic Local Alignment Search Tool analysis revealed 17 sequences in forward SSH library have high degree of similarity with disease and hypersensitive response related genes and 20 sequences with hypothetical proteins while in reverse SSH library, 23 sequences have high degree of similarity with disease and stress response-related genes and 15 sequences with hypothetical proteins. Functional analysis indicated unknown (61 and 59 %) or hypothetical functions (23 and 18 %) for most of the differentially regulated genes in forward and reverse SSH library, respectively, while others have important role in different cellular activities. Majority of the upregulated genes are related to hypersensitive response and reactive oxygen species production. Based on these expressed sequence tag data, putative role of differentially expressed genes were discussed in relation to disease. We also demonstrated the efficiency of SSH as a tool in enriching gray blight disease related up- and downregulated genes in tea. The present study revealed that many genes related to disease resistance were suppressed during P. theae infection and enhancing these genes by the application of inducers may impart better disease tolerance to the plants.