Molecular Insights into Abiotic Stresses in Mango.

Mango (Mangifera indica L.) is one of the most economically important fruit crops across the world, mainly in the tropics and subtropics of Asia, Africa, and Central and South America. Abiotic stresses are the prominent hindrance that can adversely affect the growth, development, and significant yield loss of mango trees. Understanding the molecular physiological mechanisms underlying abiotic stress responses in mango is highly intricate. Therefore, to gain insights into the molecular basis and to alleviate the abiotic stress responses to enhance the yield in the mere future, the use of high-throughput frontier approaches should be tied along with the baseline investigations. Taking these gaps into account, this comprehensive review mainly speculates to provide detailed mechanisms and impacts on physiological and biochemical alterations in mango under abiotic stress responses. In addition, the review emphasizes the promising omics approaches in unraveling the candidate genes and transcription factors (TFs) responsible for abiotic stresses. Furthermore, this review also summarizes the role of different types of biostimulants in improving the abiotic stress responses in mango. These studies can be undertaken to recognize the roadblocks and avenues for enhancing abiotic stress tolerance in mango cultivars. Potential investigations pointed out the implementation of powerful and essential tools to uncover novel insights and approaches to integrate the existing literature and advancements to decipher the abiotic stress mechanisms in mango. Furthermore, this review serves as a notable pioneer for researchers working on mango stress physiology using integrative approaches.

Conventional and Omics Approaches for Understanding the Abiotic Stress Response in Cereal Crops-An Updated Overview.

Cereals have evolved various tolerance mechanisms to cope with abiotic stress. Understanding the abiotic stress response mechanism of cereal crops at the molecular level offers a path to high-yielding and stress-tolerant cultivars to sustain food and nutritional security. In this regard, enormous progress has been made in the omics field in the areas of genomics, transcriptomics, and proteomics. Omics approaches generate a massive amount of data, and adequate advancements in computational tools have been achieved for effective analysis. The combination of integrated omics and bioinformatics approaches has been recognized as vital to generating insights into genome-wide stress-regulation mechanisms. In this review, we have described the self-driven drought, heat, and salt stress-responsive mechanisms that are highlighted by the integration of stress-manipulating components, including transcription factors, co-expressed genes, proteins, etc. This review also provides a comprehensive catalog of available online omics resources for cereal crops and their effective utilization. Thus, the details provided in the review will enable us to choose the appropriate tools and techniques to reduce the negative impacts and limit the failures in the intensive crop improvement study.

Multi-Omics and Integrative Approach towards Understanding Salinity Tolerance in Rice: A Review.

Rice (Oryza sativa L.) plants are simultaneously encountered by environmental stressors, most importantly salinity stress. Salinity is the major hurdle that can negatively impact growth and crop yield. Understanding the salt stress and its associated complex trait mechanisms for enhancing salt tolerance in rice plants would ensure future food security. The main aim of this review is to provide insights and impacts of molecular-physiological responses, biochemical alterations, and plant hormonal signal transduction pathways in rice under saline stress. Furthermore, the review highlights the emerging breakthrough in multi-omics and computational biology in identifying the saline stress-responsive candidate genes and transcription factors (TFs). In addition, the review also summarizes the biotechnological tools, genetic engineering, breeding, and agricultural practicing factors that can be implemented to realize the bottlenecks and opportunities to enhance salt tolerance and develop salinity tolerant rice varieties. Future studies pinpointed the augmentation of powerful tools to dissect the salinity stress-related novel players, reveal in-depth mechanisms and ways to incorporate the available literature, and recent advancements to throw more light on salinity responsive transduction pathways in plants. Particularly, this review unravels the whole picture of salinity stress tolerance in rice by expanding knowledge that focuses on molecular aspects.

Biofilm and hyphal inhibitory synergistic effects of phytoactives piperine and cinnamaldehyde against Candida albicans.

Oral candidiasis, the most common mycotic infection of the human oral cavity is non-life-threatening yet, if untreated, may advance as systemic infections. The ability of Candida albicans to adapt sessile lifestyle imparts resistance to drugs and host immunity. Consequently, due to the limited effectiveness of conventional antifungal treatment, novel therapeutic strategies are required. In the present study, synergistic interaction of phytochemicals, piperine, and cinnamaldehyde against the biofilm and hyphal of C. albicans was evaluated. Minimum inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) of piperine and cinnamaldehyde against C. albicans were analyzed through microbroth dilution assay and crystal violet staining method, respectively. Combinatorial biofilm and hyphal inhibitory effect were investigated through checkerboard assay. In vitro results were validated through gene expression analysis. BIC of piperine and cinnamaldehyde was determined to be 32 µg/ml and 64 µg/ml, respectively. Interaction between these two phytocomponents was found to be synergistic and six different synergistic antibiofilm combinations were identified. Microscopic analysis of biofilm architecture also evidenced the biofilm and surface adherence inhibitory potential of piperine and cinnamaldehyde combinations. Phenotypic switching between yeast and hyphal morphological forms was influenced by synergistic combinations. qPCR analysis corroborated the results of in vitro activities. nrg1 and trp1, the negative transcriptional regulators of filamentous growth were upregulated whereas other genes that are involved in biofilm formation, filamentous growth, adhesion, etc. were found to be downregulated. These proficient phytochemical combinations provide a new therapeutic avenue for the treatment of biofilm-associated oral candidiasis and to combat the recurrent infections due to antibiotic resistance.

Molecular Insights into Freezing Stress in Peach Based on Multi-Omics and Biotechnology: An Overview.

In nature or field conditions, plants are frequently exposed to diverse environmental stressors. Among abiotic stresses, the low temperature of freezing conditions is a critical factor that influences plants, including horticultural crops, decreasing their growth, development, and eventually quality and productivity. Fortunately, plants have developed a mechanism to improve the tolerance to freezing during exposure to a range of low temperatures. In this present review, current findings on freezing stress physiology and genetics in peach (Prunus persica) were refined with an emphasis on adaptive mechanisms for cold acclimation, deacclimation, and reacclimation. In addition, advancements using multi-omics and genetic engineering approaches unravel the molecular physiological mechanisms, including hormonal regulations and their general perceptions of freezing tolerance in peach were comprehensively described. This review might pave the way for future research to the horticulturalists and research scientists to overcome the challenges of freezing temperature and improvement of crop management in these conditions.

In Vitro and In Vivo Anti-infective Potential of Thymol Against Early Childhood Caries Causing Dual Species Candida albicans and Streptococcus mutans.

Early childhood caries (ECC), a severe form of caries due to cross-kingdom interaction of Candida albicans and Streptococcus mutans, is a serious childhood dental disease that affects majority of the children with poor background. The present study investigated the anti-infective potential of thymol against C. albicans and S. mutans dual species for the management of ECC. Thymol, a plant derivative of the monoterpene group, has been well known for its numerous biological activities. Thymol at 300 µg/ml concentration completely arrested growth and proliferation of dual species of C. albicans and S. mutans. Rapid killing efficacy of pathogens, within a span of 2 min, was observed in the time kill assay. In addition, at sub-inhibitory concentrations, thymol effectively diminished the biofilm formation and virulence of both C. albicans and S. mutans such as yeast-to-hyphal transition, hyphal-to-yeast transition, filamentation, and acidogenicity and acidurity, respectively, in single and dual species state. qPCR analysis was consistent with virulence assays. Also, through the invertebrate model system Galleria mellonella, in vivo toxicity and efficacy of the phytocompound was assessed, and it was found that no significant toxic effect was observed. Moreover, thymol was found to be proficient in diminishing the infection under single and dual state in in vivo condition. Overall, the results from the present study illustrate the anti-infective potential of thymol against the ECC-causing dual species, C. albicans and S. mutans, and the applicability of thymol in medicated dentifrice formulation.

Biomedical Applications and Bioavailability of Curcumin-An Updated Overview.

Curcumin, a yellow-colored molecule derived from the rhizome of Curcuma longa, has been identified as the bioactive compound responsible for numerous pharmacological activities of turmeric, including anticancer, antimicrobial, anti-inflammatory, antioxidant, antidiabetic, etc. Nevertheless, the clinical application of curcumin is inadequate due to its low solubility, poor absorption, rapid metabolism and elimination. Advancements in recent research have shown several components and techniques to increase the bioavailability of curcumin. Combining with adjuvants, encapsulating in carriers and formulating in nanoforms, in combination with other bioactive agents, synthetic derivatives and structural analogs of curcumin, have shown increased efficiency and bioavailability, thereby augmenting the range of applications of curcumin. The scope for incorporating biotechnology and nanotechnology in amending the current drawbacks would help in expanding the biomedical applications and clinical efficacy of curcumin. Therefore, in this review, we provide a comprehensive overview of the plethora of therapeutic potentials of curcumin, their drawbacks in efficient clinical applications and the recent advancements in improving curcumin's bioavailability for effective use in various biomedical applications.

Staphyloxanthin inhibitory potential of thymol impairs antioxidant fitness, enhances neutrophil mediated killing and alters membrane fluidity of methicillin resistant Staphylococcus aureus.

Staphylococcus aureus is a leading pathogen responsible for mild to severe invasive infections in humans. Especially, methicillin resistant Staphylococcus aureus (MRSA) is prevalent in hospital and community associated infections. Staphyloxanthin is a golden yellow color eponymous pigment produced by S. aureus and provides resistance to reactive oxygen species (ROS) and host neutrophil-based killing. In addition, this membrane pigment contributes to membrane rigidity and helps MRSA to survive under stress conditions. Targeting virulence of pathogen without exerting selection pressure is the recent approach to fight bacterial infections without developing drug resistance. The present study for the first time evaluated the staphyloxanthin inhibitory potential of thymol against MRSA. Qualitative and quantitative analyses demonstrated 90% of staphyloxanthin inhibition at 100 µg/mL concentration of thymol without alteration in growth. Molecular docking analysis and in vitro measurement of metabolic intermediates of staphyloxanthin revealed that thymol could possibly interact with CrtM to inhibit staphyloxanthin. Absorbance and infra red spectra further validated the inhibition of staphyloxanthin by thymol. In addition, thymol treatment significantly reduced the resistance of MRSA to ROS and neutrophil-based killing as exhibited by oxidant susceptibility assays and ex vivo innate immune clearance assay using human whole blood and neutrophils. Further, reduction in staphyloxanthin by thymol treatment increased the membrane fluidity and made MRSA cells more susceptible to membrane targeting antibiotic polymyxin B. Especially, thymol was found to be non-cytotoxic to human peripheral blood mononuclear cells. Our study validated the antivirulence potential of thymol against MRSA by inhibiting staphyloxanthin and suggests the prospective therapeutic role of thymol to combat MRSA infections.

Usnic acid deteriorates acidogenicity, acidurance and glucose metabolism of Streptococcus mutans through downregulation of two-component signal transduction systems.

The principal etiological agent of human dental caries, Streptococcus mutans is a multi-virulent pathogen that can transform commensal oral microbial community to plaque biofilms. Major virulence factors that are associated with the cariogenicity of S. mutans include adhesion, acidogenicity and acidurity. All these pathogenic traits coordinate and alter the dental plaque ecology which provide room for interaction with other similar acidogenic and aciduric bacteria. This cariogenic flora increases the possibility of enamel demineralization which headway to caries development. The present study was aimed at evaluating the antimicrobial and antiinfective potential of a lichen secondary metabolite usnic acid (UA) against S. mutans. Minimum inhibitory concentration (MIC), Minimum bactericidal concentration (MBC) and growth kinetics were evaluated to determine the antimicrobial potential of UA against S. mutans. UA at 5 µg mL-1 and 10 µg mL-1 concentration were considered as MIC and MBC respectively. Effect on biofilm formation was microscopically assessed and found to be reduced in a concentration dependent manner. Gene expression of gtfB, gtfC, gtfD, vicR, ComDE and smu0630 was found to be downregulated upon treatment with sub-MIC of UA. Acidogenicity, acidurity, eDNA synthesis and response to oxidative stress were found to be attenuated by the influence of UA. It was also demonstrated to act on preformed mature biofilm of S. mutans. Moreover, UA was shown to possess very low frequency to acquire spontaneous resistance development in S. mutans. Besides, no morphological aberrations or toxic effect was instigated by UA in the human buccal epithelial cells as well as to the oral commensals. Altogether, these results demonstrate the therapeutic potential of usnic acid in the treatment of S. mutans infection.

Sapindus mukorossi Gaertn. and its bioactive metabolite oleic acid impedes methicillin-resistant Staphylococcus aureus biofilm formation by down regulating adhesion genes expression.

Plants are boon to the mankind due to plenty of metabolites with medicinal values. Though plants have traditionally been used to treat various diseases, their biological values are not completely explored yet. Sapindus mukorossi is one such ethnobotanical plant identified for various biological activities. As biofilm formation and biofilm mediated drug resistance of methicillin-resistant Staphylococcus aureus (MRSA) have raised as serious global issue, search for antibiofilm agents has gained greater importance. Notably, antibiofilm potential of S. mukorossi is still unexplored. The aim of the study is to explore the effect of S. mukorossi methanolic extract (SMME) on MRSA biofilm formation and adhesive molecules production. Significantly, SMME exhibited 82 % of biofilm inhibition at 250 µg/mL without affecting the growth and microscopic analyses evidenced the concentration dependent antibiofilm activity of SMME. In vitro assays exhibited the reduction in slime, cell surface hydrophobicity, autoaggregation, extracellular polysaccharides substance and extracellular DNA synthesis upon SMME treatment. Further, qPCR analysis confirmed the ability of SMME to interfere with the expression of adhesion genes associated with biofilm formation such as icaA, icaD, fnbA, fnbB, clfA, cna, and altA. GC-MS analysis and molecular docking study revealed that oleic acid is responsible for the antibiofilm activity. FT-IR analysis validated the presence of oleic acid in SMME. These results suggest that SMME can be used as a promising therapeutic agent against MRSA biofilm-associated infections.

Synergistic Interaction of Piperine and Thymol on Attenuation of the Biofilm Formation, Hyphal Morphogenesis and Phenotypic Switching in Candida albicans.

The incidence of fungal infections has significantly increased in recent years due to the emergence of antifungal resistance. Biofilm formation is considered to be a major contributor to both the infectious diseases and to antimicrobial resistance. Consequently, biofilm-associated infections are often problematic to treat with existing therapeutics. Adhesion of C. albicans to the host surface or implanted materials followed by hyphal invasion and biofilm formation enhances C. albicans pathogenicity and virulence. Thus, developing a therapeutic agent that inhibits candidal adherence, biofilm development and morphological switching could improve clinical management of infections. The present investigation studied two emerging and alternatives strategies, namely antibiofilm and combinatorial approach, to attenuate biofilm formation and the expression of Candida virulence factors. Piperine and thymol are major bioactive components of pepper and thyme, respectively. These phytochemicals are known to possess numerous biological activities, including recently reported antibiofilm effects against C. albicans. The minimum biofilm inhibitory concentration (MBIC) of both phytochemicals was determined to be 32 µg/ml. The phytochemical treatment of Candida biofilms using piperine and thymol revealed synergistic effects at four different combinations of concentrations, i.e. 8 and 8, 8 and 4, 8 and 2 and 4 and 8 µg/ml. These synergistic combinations resulted in the significant reduction in adherence of Candida, hyphal extension and morphological transformation. Moreover, limited exposure of synergistic combinations controlled the hyphal elongation. Results were validated through the gene expression analysis. Results from the present investigation suggest that piperine and thymol can be synergistically employed for the treatment of biofilm-associated C. albicans infection.

Ethnomedicines of Indian origin for combating COVID-19 infection by hampering the viral replication: using structure-based drug discovery approach.

In the present study, we have explored the interaction of the active components from 10 different medicinal plants of Indian origin that are commonly used for treating cold and respiratory-related disorders, through molecular docking analysis. In the current scenario, COVID-19 patients experience severe respiratory syndromes, hence it is envisaged from our study that these traditional medicines are very likely to provide a favourable effect on COVID-19 infections. The active ingredients identified from these natural products are previously reported for antiviral activities against large group of viruses. Totally 47 bioactives identified from the medicinal plants were investigated against the structural targets of SARS-CoV-2 (Mpro and spike protein) and human ACE2 receptor. The top leads were identified based on interaction energies, number of hydrogen bond and other parameters that explain their potency to inhibit SARS-CoV-2. The bioactive ligands such as Cucurbitacin E, Orientin, Bis-andrographolide, Cucurbitacin B, Isocucurbitacin B, Vitexin, Berberine, Bryonolic acid, Piperine and Magnoflorine targeted the hotspot residues of SARS-CoV-2 main protease. In fact, this protease enzyme has an essential role in mediating the viral replication and therefore compounds targeting this key enzyme are expected to block the viral replication and transcription. The top scoring conformations identified through docking analysis were further demonstrated with molecular dynamics simulation. Besides, the stability of the conformation was studied in detail by investigating the binding free energy using MM-PBSA method. Overall, the study emphasized that the proposed hit Cucurbitacin E and orientin could serve as a promising scaffold for developing anti-COVID-19 drug.Communicated by Ramaswamy H. Sarma.

Carvacrol Targets SarA and CrtM of Methicillin-Resistant Staphylococcus aureus to Mitigate Biofilm Formation and Staphyloxanthin Synthesis: An In Vitro and In Vivo Approach.

Carvacrol is an essential oil traditionally used in culinary processes as spice due to its aromatic nature and also known for various biological activities. In the present study, the antivirulence efficacy of carvacrol against methicillin-resistant Staphylococcus aureus (MRSA) is explored. MRSA is an opportunistic pathogen capable of causing various superficial and systemic infections in humans. Biofilm formation and virulence factors of MRSA are responsible for its pathogenesis and resistance. Hence, the aim of this study was to explore the antibiofilm and antivirulence efficacy of carvacrol against MRSA. Carvacrol at 75 µg/mL inhibited MRSA biofilm by 93%, and it also decreased the biofilm formation on polystyrene and glass surfaces. Further, microscopic analyses revealed the reduction in microcolony formation and collapsed structure of biofilm upon carvacrol treatment. The growth curve analysis and the Alamar blue assay showed the nonfatal effect of carvacrol on MRSA. Further, carvacrol significantly reduced the production of MRSA biofilm-associated slime and extracellular polysaccharide. In addition, carvacrol strongly inhibited the antioxidant pigment staphyloxanthin and its intermediates' synthesis in MRSA. Inhibition of biofilm and staphyloxanthin by carvacrol enhanced the susceptibility of MRSA to oxidants and healthy human blood. Quantitative polymerase chain reaction (qPCR) analysis unveiled the downregulation of sarA-mediated biofilm gene expression and staphyloxanthin-associated crtM gene expression. The sarA-dependent antibiofilm potential of carvacrol was validated using S. aureus Newman wild-type and isogenic ΔsarA strains. In silico molecular docking analysis showed the high binding efficacy of carvacrol with staphylococcal accessory regulator A (SarA) and 4,4'-diapophytoene synthase (CrtM) when compared to positive controls. Furthermore, the in vivo efficacy of carvacrol against MRSA infection was demonstrated using the model organism Galleria mellonella. The results revealed the nontoxic nature of carvacrol to the larvae and the rescuing potential of carvacrol against MRSA infection. Finally, the current study reveals the potential of carvacrol in inhibiting the biofilm formation and staphyloxanthin synthesis of MRSA by targeting the global regulator SarA and a novel antivirulence target CrtM.

Piperine Impedes Biofilm Formation and Hyphal Morphogenesis of Candida albicans.

Candida albicans is the primary etiological agent associated with the pathogenesis of candidiasis. Unrestricted growth of C. albicans in the oral cavity may lead to oral candidiasis, which can progress to systemic infections in worst scenarios. Biofilm of C. albicans encompasses yeast and hyphal forms, where hyphal formation and yeast to hyphal morphological transitions are contemplated as the key virulence elements. Current clinical repercussions necessitate the identification of therapeutic agent that can limit the biofilm formation and escalating the susceptibility of C. albicans to immune system and conventional antifungals. In the present study, a plant-derived alkaloid molecule, piperine, was investigated for the antibiofilm and antihyphal activities against C. albicans. Piperine demonstrated a concentration-dependent antibiofilm activity without exerting negative impact on growth and metabolic activity. Inhibition in the hyphal development was witnessed through confocal laser-scanning microscopy and scanning electron microscopy. Interestingly, piperine displayed a tremendous potential to inhibit the virulence-associated colony morphologies, such as filamentation and wrinkling. Furthermore, piperine regulated morphological transitions between yeast and hyphal forms by inhibiting hyphal extension and swapping hyphal phase to yeast forms yet under filamentation-inducing circumstances. Remarkably, piperine-challenged C. albicans exhibited low potential for spontaneous antibiofilm resistance development. In addition, piperine effectively reduced in vivo colonization and prolonged survival of C. albicans-infected Caenorhabditis elegans, thereby expounding the distinct antivirulent potential. Transcriptomic analysis revealed piperine significantly downregulating the expression of several biofilm related and hyphal-specific genes (ALS3, HWP1, EFG1, CPH1, etc.). Furthermore, no acute toxicity was observed in the HBECs and nematodes exposed to piperine. Altogether, results from this study reveals the potential of piperine to inhibit biofilm and hyphal morphogenesis, and its in vivo efficacy and innocuous nature to HBECs suggests that piperine may be considered as a potential candidate for the treatment of biofilm-associated C. albicans infection, especially for oral candidiasis.

Proteomic profiling unveils citral modulating expression of IsaA, CodY and SaeS to inhibit biofilm and virulence in methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the dangerous human pathogens and it is categorized as a high priority multi-drug resistant bacterium by WHO. Biofilm forming ability of MRSA is responsible for persistent infections and also difficult to eradicate using antibiotic therapy as biofilm is much more resistant to antibiotics. Thus, targeting biofilm and virulence has become an alternative approach to attenuate the pathogenicity of bacterium without affecting the growth. Hence, the present study was aimed at evaluation of antibiofilm potential of citral against MRSA and to decode the possible mode of action. Citral inhibited biofilm formation by MRSA without affecting growth at 100 µg/mL. Microscopic analyses evidenced that citral greatly hampered the surface adherence of MRSA. Effect of citral on cellular proteome of MRSA was studied using two-dimensional gel electrophoresis (2DGE) and differentially regulated proteins were identified using nano LC-MS/MS and MALDI-TOF/TOF analysis. Gene ontology and STRING analysis revealed that citral differentially regulated the proteins involved in pleotropic transcriptional repression (CodY), cell wall homeostasis (IsaA), regulation of exotoxin secretion (SaeS), cell adhesion, hemolysis, capsular polysaccharide biosynthesis and pathogenesis. Gene expression analysis and in vitro assays further validated the alteration in synthesis of slime, hemolysin, lipase, staphyloxanthin and oxidant susceptibility. Thus, the present study unveiled the multiple protein targeted antibiofilm potential of citral and portrays citral as a promising therapeutic agent to combat biofilm mediated MRSA infections with less possibility of resistance development.

Global proteomic analysis deciphers the mechanism of action of plant derived oleic acid against Candida albicans virulence and biofilm formation.

Candida albicans is a commensal fungus in humans, mostly found on the mucosal surfaces of the mouth, gut, vagina and skin. Incidence of ever increasing invasive candidiasis in immunocompromised patients, alarming occurrence of antifungal resistance and insufficient diagnostic methods demand more focused research into C. albicans pathogenicity. Consequently, in the present study, oleic acid from Murraya koenigii was shown to have the efficacy to inhibit biofilm formation and virulence of Candida spp. Results of in vitro virulence assays and gene expression analysis, impelled to study the protein targets which are involved in the molecular pathways of C. albicans pathogenicity. Proteomic studies of differentially expressed proteins reveals that oleic acid induces oxidative stress responses and mainly targets the proteins involved in glucose metabolism, ergosterol biosynthesis, lipase production, iron homeostasis and amino acid biosynthesis. The current study emphasizes anti-virulent potential of oleic acid which can be used as a therapeutic agent to treat Candida infections.

Impediment to growth and yeast-to-hyphae transition in Candida albicans by copper oxide nanoparticles.

The effects of two prominent copper oxide nanoparticles (CuO-NP and Cu2O-NP), with the oxidation state of Cu++ (cupric) and Cu+ (cuprous), on Candida albicans were evaluated. CuO-NP and Cu2O-NP were synthesized and characterized by XRD, FESEM, HR-TEM and Zeta potential. At sub-MIC (50 µg ml-1), both cupric and cuprous oxide NPs prevented yeast-to-hyphae switching and wrinkling behaviour in C. albicans. The mechanism for the antifungal action of the two NPs differed; CuO-NP significantly elicited reactive oxygen species, whereas membrane damage was more pronounced with Cu2O-NP. Real time PCR analysis revealed that CuO-NP suppressed the morphological switching of yeast-to-hyphae by down-regulating cph1, hst7 and ras1 and by up-regulation of the negative regulator tup1. In comparison, Cu2O-NP resulted in down-regulation of ras1 and up-regulation of the negative regulators nrg1 and tup1. Between the two NPs, CuO exhibited increased antifungal activity due to its stable oxidation state (Cu++) and its smaller dimensions compared with Cu2O-NP.

5-Dodecanolide interferes with biofilm formation and reduces the virulence of Methicillin-resistant Staphylococcus aureus (MRSA) through up regulation of agr system.

Methicillin resistant Staphylococcus aureus (MRSA) is a predominant human pathogen with high morbidity that is listed in the WHO high priority pathogen list. Being a primary cause of persistent human infections, biofilm forming ability of S. aureus plays a pivotal role in the development of antibiotic resistance. Hence, targeting biofilm is an alternative strategy to fight bacterial infections. The present study for the first time demonstrates the non-antibacterial biofilm inhibitory efficacy of 5-Dodecanolide (DD) against ATCC strain and clinical isolates of S. aureus. In addition, DD is able to inhibit adherence of MRSA on human plasma coated Titanium surface. Further, treatment with DD significantly reduced the eDNA synthesis, autoaggregation, staphyloxanthin biosynthesis and ring biofilm formation. Reduction in staphyloxanthin in turn increased the susceptibility of MRSA to healthy human blood and H2O2 exposure. Quantitative PCR analysis revealed the induced expression of agrA and agrC upon DD treatment. This resulted down regulation of genes involved in biofilm formation such as fnbA and fnbB and up regulation of RNAIII, hld, psmα and genes involved in biofilm matrix degradation such as aur and nuc. Inefficacy of DD on the biofilm formation of agr mutant further validated the agr mediated antibiofilm potential of DD. Notably, DD was efficient in reducing the in vivo colonization of MRSA in Caenorhabditis elegans. Results of gene expression studies and physiological assays unveiled the agr mediated antibiofilm efficacy of DD.

Molecular modeling, simulation and virtual screening of ribosomal phosphoprotein P1 from Plasmodium falciparum.

Ribosomal phosphoprotein P1 (RPP1) is acidic phosphoprotein which in association with neutral phosphoprotein P0 and acidic phosphoprotein P2 forms ribosomal P protein complex as (P1)2-P0-(P2)2. P protein is known to be immunogenic and has important role in protein translation. 3D structure of P1 is not known. We have built an ab-initio model of RPP1 of Plasmodium falciparum using I-TASSER. Stereochemical stability of structure was checked using PROCHECK and the normality of the local environment of amino acids was checked using WHATIF. Comparison between known protein structures in PDB database and model protein was done using Dali server. Molecular dynamic simulation study and virtual screening of RPP1 was carried out. Three dimensional model structure of RPP1 was generated and model validation studies proved the model to be steriochemically significant. RPP1 structure was found to be stable at room temperature in water environment demonstrated by 30 ns molecular dynamic simulation study. Dali superimposition showed 69% superimposition to known 3D structures in PDB. Further virtual screening and docking studies promoted good interaction of ligands Ecgonine, Prazepam and Ethyl loflazepate with RPP1. The work provides insight for molecular understanding of RPP1 of P. falciparum and can be used for development of antimalarial drugs.

Improvement on dissolution rate of inclusion complex of Rifabutin drug with ß-cyclodextrin.

The effect of ß-cyclodextrin (ß-CD) on the improvement of solubility and antimicrobial activity of poorly water soluble drug Rifabutin (RFB) was studied. The solid inclusion complex is prepared under different methods and it is characterized by FT-IR, XRD, DSC and SEM methods. Solubility type, stability constant, stoichiometric ratio were investigated from phase solubility diagram of inclusion complex (RFB with ß-CD). The dissolution profiles of the inclusion complexes were carried out and obvious increase in dissolution rate was observed when compared with pure RFB drug. Inclusion complexation process was further confirmed by molecular docking studies using PatchDock server. The in vitro antimicrobial and antibiofilm activity of RFB sensible microorganisms was significantly increased by on inclusion complexation process. This trend of inclusion complexation of poorly water soluble drugs is highly recognized as a successful and useful approach for the application in pharmaceutical field.