Antagonistic, biofilm-forming rhizospheric Pseudomonas spp. isolated from Hail province

Background: The objectives of this study were to characterize Pseudomonas rhizospheric strains, that have a biocontrol activity, in rhizosphere soil in Hail province and study their ability to form biofilm.Methods: Rhizosphere soil samples were collected from rhizosphere of soil plantation areas, to be used for bacteria isolation. The identified bacteria were qualitatively tested for their ability to produce slime and subsequently develop biofilm.Results: The cultural and biochemical identification techniques, including morphological, biochemical and molecular methods revealed that the antagonistic bacteria- from the distinctive rhizosphere soil samples belong to Pseudomonas genus in particular, P. aeruginosa (PF1a, pf2a, PF-8) and P. putida (PF-7). These identified isolates inhibited Aspergillus niger development with percentage of parasitic growth inhibition greater than (48.095 ± 2.182)% for P. aeruginosa (pf-8). In addition, these identified isolates were significantly shown to be able to produce exopolysaccharide and subsequently develop biofilm on polystyrene and glass surfaces.Conclusion: Superior strains of these bio-control and plant growth promoting rhizobacteria will enable for better biological control of fungal and bacterial plant diseases and may reduce chemical pesticide usage. The indigenous strains isolated could potentially have a great impact on controlling plant diseases, in particular, those caused by microorganisms, and could be used as an alternative bio control agents instead of harmful chemical pesticides. Most of the tried microbes produced exopolysaccharides as well as formed biofilm on polystyrene and glass surfaces.Keywords: Biological control, Rhizosphere; Biofilm; Pseudomonas; Antimicrobial

In-vitro anti-Vibrio spp. activity and chemical composition of some Tunisian aromatic plants

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Fish-based Bioactives as Potent Nutraceuticals: Exploring the Therapeutic Perspective of Sustainable Food from the Sea

Recent developments in nutraceuticals and functional foods have confirmed that bioactive components present in our diet play a major therapeutic role against human diseases. Moreover, there is a huge emphasis on food scientists for identifying and producing foods with better bioactive activity, which can ultimately provide wellness and well-being to human health. Among the several well-known foods with bioactive constituents, fish has always been considered important, due to its rich nutritional values and by-product application in food industries. Nutritionists, food scientists, and other scientific communities have been working jointly to uncover new bioactive molecules that could increase the potential and therapeutic benefits of these bioactive components. Despite the innumerable benefits of fish and known fish bioactive molecules, its use by food or pharmaceutical industries is scarce, and even research on fish-based nutraceuticals is not promising. Therefore, this review focuses on the current information/data available regarding fish bioactive components, its application as nutraceuticals for therapeutic purposes in the treatment of chronic diseases, ethnic issues related to consumption of fish or its by-products. Especial emphasis is given on the utilization of fish wastes and its by-products to fulfill the world demand for cheap dietary supplements specifically for underdeveloped/least developed countries

Profiling and Role of Bioactive Molecules from Puntius sophore (Freshwater/Brackish Fish) Skin Mucus with Its Potent Antibacterial, Antiadhesion, and Antibiofilm Activities

Epidermal fish mucus comprises of diverse bioactive metabolites which plays an immense role in defense mechanisms and other important cellular activities. Primarily, this study aims to screen the unexplored mucus extract of Puntius sophore (P. sophore) for its antagonistic potential against common pathogens, which are commonly implicated in foodborne and healthcare associated infections, with effects on their adhesion and biofilm formation. Profiling of the skin mucus was carried out by High Resolution-Liquid Chromatography Mass Spectrometry (HR-LCMS), followed by antibacterial activity and assessment of antibiofilm potency and efficacy on the development, formation, and texture of biofilms. Furthermore, bacterial cell damage, viability within the biofilm, checkerboard test, and cytotoxicity were also evaluated. As a result, P. sophore mucus extract was found to be effective against all tested strains. It also impedes the architecture of biofilm matrix by affecting the viability and integrity of bacterial cells within biofilms and reducing the total exopolysaccharide content. A synergy was observed between P. sophore mucus extract and gentamicin for Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Bacillus subtilis (B. subtilis), whereas, an additive effect for Staphylococcus aureus (S. aureus). Thus, our findings represent the potent bioactivities of P. sophore mucus extract for the first time, which could be explored further as an alternative to antibiotics or chemically synthesized antibiofilm agents

Assessment of Antimicrobial and Antioxidant Activity of methanolic extract from Arnebia decumbens aerial parts growing wild in Aja Mountain

Background: Many plants are a rich source of secondary metabolites with potential antimicrobial and antioxidant properties. Amongst the customary plant herbs used as a phytomedicine in Hail province, which has been selected for the current study, Kehail plant, Arnebia decumbens (A. decumbens). Therefore, this study sought to assess the antimicrobial and antioxidant activities against high-risk bacteria and yeasts.Methods: The cup plate agar diffusion methods and Microdilution assays were adopted with minor modifications to assess the antibacterial activity. The Qualitative and quantitative tests were employed to assess the Kehail antioxidant activities by determining its phytochemicals, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ABTS(2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and β-carotene in vitro assays.Results: The results indicated that methanolic Kehail extract (M.K.E.) exhibited antibacterial activity against pathogenic bacteria, including Staphylococcus epidermidis (M13), Enterobacter cloacae, Pseudomonas aeruginosa, Escherichia coli ATCC 10536 and Klebsiella pneumoniae, while the mean inhibition zone was 10.66 ± 0.57 mm, 10.77 ± 0.57735 mm, 10.33 ± 0.57 mm, and 9.55 ± 0.57 mm, respectively. Furthermore, the antimicrobial activity increased in a concentration-dependent manner. Indeed, E. cloacae were the plant extract most inhibited bacteria. The plant extract has vigorous antifungal activity against Candida albicans ATCC 10231 and C. tropicalis ATCC 9362, whereas the mean inhibition zone was 12.77 ± 0.57 and 13.11 ± 1.52 mm, respectively. The extract of A. decumbens plant was also proven to be efficient as a source of antioxidants saponins, terpenes, polyphenols, and flavonoids.Conclusion: The acquired outcomes uncover promising antioxidant activities of the tested Kehail methanolic extract. The study encourages the separation of active components and the development of new medications from the Kehail plant.Keywords: Arnebia decumbens; Methanolic extract; Disk diffusion assay; Microdilution assay; Antioxidant activities   

Biological activities evaluation of enantiopure isoxazolidine derivatives: in vitro, in vivo and in silico studies

A series of enantiopure isoxazolidines (3a–c) were synthesized by 1,3-dipolar cycloaddition between a (−)-menthone-derived nitrone and various terminal alkenes. The screened compounds were evaluated for their antioxidant activity by two in vitro antioxidant assays, including β-carotene/linoleic acid bleaching, and inhibition of lipid peroxidation (thiobarbituric acid reactive species, TBARS). The results revealed that compound 3b (EC50 = 0.55 ± 0.09 mM) was the most potent antioxidant as compared to the standard drug (EC50 = 2.73 ± 0.07 mM) using the TBARS assay. Furthermore, the antimicrobial activity was assessed using disc diffusion and microdilution methods. Among the synthesized compounds, 3c was found to be the most potent antimicrobial agent as compared to the standard drug. Subsequently, the acute toxicity study has also been carried out for the newly synthesized compounds and the experimental studies revealed that all compounds were safe up to 500 mg/kg and no death of animals were recorded. The cytotoxicity of these compounds was assessed by the MTT cell proliferation assay against the continuous human cell lines HeLa and compound 3c (GI50 = 46.2 ± 1.2 μM) appeared to be more active than compound 3a (GI50 = 200 ± 2.8 μM) and 3b (GI50 = 1400 ± 7.8 μM). Interestingly, all tested compounds displayed a good α-amylase inhibitory activity in competitive manner with IC50 values ranging between 23.7 and 64.35 μM when compared to the standard drug acarbose (IC50 = 282.12 μM). In addition, molecular docking studies were performed to understand the possible binding and the interaction of the most active compounds to the α-amylase pocket.info:eu-repo/semantics/publishedVersio

Bioactivity and chemical characterization of Opuntia macrorhiza Engelm. seed oil: potential food and pharmaceutical applications

In the food industry, there is a continuous search for ingredients that might provide advantageous properties to food products, either considering their nutritional value or bioactivity, as well as flavouring and technological aspects. Crude oils are good examples of this type of ingredient, especially if obtained from nonconventional sources. Accordingly, the Opuntia macrorhiza Engelm. seed oil (OMSO) was chemically characterized and evaluated for different in vitro and in vivo bioactivities. OMSO presented physicochemical characteristics appropriate to be considered as an edible oil, namely low acidity value, stability to oxidation (high peroxide value and low K 232 and K 270 values), and high contents of unsaturated fatty acids (as shown by the iodine value) and saponifiable matter. Furthermore, this natural oil, owing to its rich phytochemical profile, showed relevant antioxidant activity (especially in lipid peroxidation inhibition assays), a-glucosidase inhibitory activity, cytotoxicity against human tumour cell lines, antibacterial (mainly against Gram positive species) and antifungal properties, as well as anti-inflammatory and analgesic activities. Furthermore, OMSO did not show any sign of acute toxicity on animals, highlighting its possible use in different applications, considering that this natural product is not expected to induce the adverse effects typically associated with synthetic bioactive agents (e.g., ampicillin, amphotericin B, or lysine acetylsalicilate).The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011) and J.C.M. Barreira and Ricardo C. Calhelha contracts.info:eu-repo/semantics/publishedVersio

Cordycepin for Health and Wellbeing: A Potent Bioactive Metabolite of an Entomopathogenic Medicinal Fungus Cordyceps with Its Nutraceutical and Therapeutic Potential

Cordyceps is a rare naturally occurring entomopathogenic fungus usually found at high altitudes on the Himalayan plateau and a well-known medicinal mushroom in traditional Chinese medicine. Cordyceps contains various bioactive components, out of which, cordycepin is considered most vital, due to its utmost therapeutic as well as nutraceutical potential. Moreover, the structure similarity of cordycepin with adenosine makes it an important bioactive component, with difference of only hydroxyl group, lacking in the 3′ position of its ribose moiety. Cordycepin is known for various nutraceutical and therapeutic potential, such as anti-diabetic, anti-hyperlipidemia, anti-fungal, anti-inflammatory, immunomodulatory, antioxidant, anti-aging, anticancer, antiviral, hepato-protective, hypo-sexuality, cardiovascular diseases, antimalarial, anti-osteoporotic, anti-arthritic, cosmeceutical etc. which makes it a most valuable medicinal mushroom for helping in maintaining good health. In this review, effort has been made to bring altogether the possible wide range of cordycepin’s nutraceutical potential along with its pharmacological actions and possible mechanism. Additionally, it also summarizes the details of cordycepin based nutraceuticals predominantly available in the market with expected global value. Moreover, this review will attract the attention of food scientists, nutritionists, pharmaceutical and food industries to improve the use of bioactive molecule cordycepin for nutraceutical purposes with commercialization to aid and promote healthy lifestyle, wellness and wellbeing

Mechanistic insights into MARK4 inhibition by galantamine toward therapeutic targeting of Alzheimer’s disease

Introduction: Hyperphosphorylation of tau is an important event in Alzheimer’s disease (AD) pathogenesis, leading to the generation of “neurofibrillary tangles,” a histopathological hallmark associated with the onset of AD and related tauopathies. Microtubule-affinity regulating kinase 4 (MARK4) is an evolutionarily conserved Ser-Thr (S/T) kinase that phosphorylates tau and microtubule-associated proteins, thus playing a critical role in AD pathology. The uncontrolled neuronal migration is attributed to overexpressed MARK4, leading to disruption in microtubule dynamics. Inhibiting MARK4 is an attractive strategy in AD therapeutics.Methods: Molecular docking was performed to see the interactions between MARK4 and galantamine (GLT). Furthermore, 250 ns molecular dynamic studies were performed to investigate the stability and conformational dynamics of the MARK4–GLT complex. We performed fluorescence binding and isothermal titration calorimetry studies to measure the binding affinity between GLT and MARK4. Finally, an enzyme inhibition assay was performed to measure the MARK4 activity in the presence and absence of GLT.Results: We showed that GLT, an acetylcholinesterase inhibitor, binds to the active site cavity of MARK4 with an appreciable binding affinity. Molecular dynamic simulation for 250 ns demonstrated the stability and conformational dynamics of the MARK4–GLT complex. Fluorescence binding and isothermal titration calorimetry studies suggested a strong binding affinity. We further show that GLT inhibits the kinase activity of MARK4 significantly (IC50 = 5.87 µM).Conclusion: These results suggest that GLT is a potential inhibitor of MARK4 and could be a promising therapeutic target for AD. GLT’s inhibition of MARK4 provides newer insights into the mechanism of GLT’s action, which is already used to improve cognition in AD patients

Cytoplasmic amino acid profiles of clinical and ATCC 29213 strains of Staphylococcus aureus harvested at different growth phases

Staphylococcus aureus strains are a great contributor to both hospital acquired infections as well as community acquired infections. The objective of the present investigation was to compare potential differences in cytoplasmic amino acid levels between clinical and ATCC 29213 strains of S. aureus. The two strains were grown under ideal conditions to mid-exponential and stationary growth phases, after which they were harvested to analyze their amino acid profiles. Initially, the amino acid patterns of both strains were compared at the mid-exponential phase when grown in controlled conditions. At the mid-exponential phase, both strains shared common features in cytoplasmic amino acid levels, with glutamic acid, aspartic acid, proline, and alanine identified as key amino acids. However, the concentration profiles of seven amino acids exhibited major variances between the strains, even though the total cytoplasmic levels of amino acids did not alter significantly. At the stationary phase, the magnitudes of the amino acids abundant in the mid-exponential phase were altered. Aspartic acid became the most abundant amino acid in both strains accounting for 44% and 59% of the total amino acids in the clinical and ATCC 29213 strains, respectively. Lysine was the second most abundant amino acid in both strains, accounting for 16% of the total cytoplasmic amino acids, followed by glutamic acid, the concentration of which was significantly higher in the clinical strain than in the ATCC 29213 strain. Interestingly, histidine was clearly present in the clinical strain but was virtually lacking in the ATCC 29213 strain. This study reveals the dynamic diversity of amino acid levels among strains, which is an essential step toward illustrating the variability in S. aureus cytoplasmic amino acid profiles and could be significant in explaining variances among strains of S. aureus