This research presents the first comprehensive investigation into the phytochemical and nutraceutical properties of Viola stocksii. The study aimed to identify the therapeutic efficacy and bioactive constituents of this medicinal herb, traditionally used as an herbal tea for managing respiratory and abdominal issues in remote areas of Pakistan. The therapeutic efficacy of the plant was assessed as an anti-oxidant-rich health tonic coupled with anti-inflammatory and immunomodulatory activities against COVID-19 and its evolving variants. The study involved sequential extraction, bio-assay guided fractionation, isolation, characterization, and biological evaluation. Preliminary in vitro studies have demonstrated that polar fractions of the plant possess significant antioxidant and antiinflammatory potential. A diverse combination of chromatographic techniques (Diaion resin HP-20, Sephadex LH-20, ODS-C18, and RP-HPLC) facilitated the purification of active constituents of the plant. Comprehensive analysis of NMR (1H, 13C, and 2D NMR) and mass (EIMS, HR-EIMS, and FAB-HRMS) spectral data lead to characterize the isolated compounds (1–4) as flavonoid glycosides. Results from in vitro and in-silico evaluations revealed that the isolated glycosides exhibit high antioxidant, antiinflammatory, and immunomodulatory activities, which synergistically show promising potential in combating SARS-CoV-2 variants. Besides MPro, therapeutic potential against two unexplored proteins i.e. the spike trimer (7WZ1) and surface glycoproteins (7QTJ) was studied for the first time. Kaempferol (KamGluαRh) and quercetin (QurGluαRh) carrying rutinoside, were identified as the most active constituents of the plant, with the highest binding affinities in the range of −10 to −13 kcal/mol. Ten distinct active regions were explored on the spike trimer, including strong binding affinity with the essential RBD region, spike head, and tail of the protein. MD simulation validated the stability of Mpro-KamGluαRh and Mpro-QurGluαRh complexes evidenced by an average RMSD of 0.2 nm led to the mechanistic understanding of Mpro inhibition. ADMET and pharmacokinetic studies authenticated the therapeutic ability and drug-likeness profiling of all extracted compounds. Results revealed the beneficial role of glycosides in boosting the medicinal effectiveness of flavonoids and the potential of Viola stocksii as an immunity booster against respiratory infections like COVID-19.
Bacterial biofilms are formed by a complex community of microorganisms, held together by a matrix that provides structural support and stability to microbial communities, making infections associated with biofilms more difficult to treat. In the face of growing research in the health area in search of antibiotics with action against biofilms, natural products present an effective alternative strategy. In this context, the aim of this study was to evaluate bacterial biofilm formation, assess the susceptibility of planktonic cells to diosgenin, and examine its efficacy on inhibiting and treating biofilms. The broth microdilution method was used to determine the Minimum Inhibitory Concentration (MIC). Six bacterial strains were tested: Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 9027, Pseudomonas aeruginosa 24, Enterococcus faecalis INCQS 0017, Enterococcus faecalis INCQS 00018, and Enterococcus faecalis INCQS 654. The crystal violet method was employed to evaluate the potential of diosgenin in biofilm inhibition and eradication. Chlorhexidine gluconate served as a reference standard for the antibiofilm assays, along with the antibiotics norfloxacin, ampicillin, and gentamicin. MIC determination revealed that diosgenin exhibited intrinsic antimicrobial activity, with an MIC of 406 μg/mL against S. aureus ATCC 25923. The antibiofilm activity showed significant inhibition for E. faecalis 17 and moderate inhibition against E. faecalis 654 and S. aureus 25923. Furthermore, diosgenin effectively eradicated preformed biofilms of S. aureus 25923 and P. aeruginosa 9027, indicating its ability to interfere with biofilm biomass. These results suggest that diosgenin not only inhibits bacterial biofilm formation but also eradicates established biofilms, highlighting it as a promising candidate for the development of products aimed at combating bacterial biofilms.
To compare γ-glutamyl di- and tripeptides generated by different Bacillus strains and investigate the impact of substrates on the production of γ-glutamyl peptides, six strains of four species, including B. subtilis, B. velezensis, B. amyloliquefaciens and B. paralicheniformis, were cultivated in a standard brain heart infusion (BHI) broth and a medium consisting of hemoglobin hydrolysates (HH) for six days. Quantitative analysis of free amino acids and γ-glutamyl peptides, as well as determination of bacterial growth and γ-glutamyltransferase activity were carried out. Results revealed that all Bacillus strains could generate a series of γ-glutamyl dipeptides in both media. Most strains produced higher concentrations of target peptides in the HH medium (up to 83.56 μM), which correlated with higher levels of free amino acids in the medium. Glutathione was detected only in the BHI medium with B. subtilis PRO84, B. velezensis PRO76, B. altitudinis PRO107, and B. paralicheniformis PRO109 (up to 0.61 μM), indicating the glutathione-forming ability of these Bacillus strains. Production of γ-glutamyl peptides was influenced by both the choice of strain and growth medium, with the medium exerting a more pronounced impact than the strain. This study highlights the importance of selecting the appropriate substrate and Bacillus strains to produce desired γ-glutamyl peptides as enhancers of koku, potentially inspiring the conversion of meat side streams into valuable kokumi seasonings.
Cadmium (Cd) is an environmental non-biodegradable pollutant that induces toxic effects in humans. Therefore, there is a pressing need to identify new methods to relieve cadmium-induced toxic damage. In this study, Weizmannia coagulans (formerly termed Bacillus coagulans) LBK, which was isolated from silage feed, exhibited robust Cd tolerance and adsorption capabilities. In vitro experiments demonstrated that its scavenging rate for 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and hydroxyl radicals was 40% and 39%, respectively. In vivo, LBK significantly reduced the mortality rate of cadmium-exposed mice. Moreover, LBK increased the hepatic levels of superoxide dismutase (SOD) and catalase (CAT), and histopathology examination suggested that LBK could attenuate liver damage. W. coagulans LBK significantly altered the composition of the intestinal microbiota and increased the abundance of beneficial bacteria such as Leptospirillaceae and Lactobacillus. Metabolomics analysis of cecal contents revealed that LBK regulated amino acid metabolic disorders caused by Cd exposure and restored the levels of glutamic acid, leucine, and aspartic acid. Based on the aforementioned advantages, W. coagulans LBK may be considered a promising candidate for alleviating oxidative stress caused by acute Cd exposure.
The potential to directly fortify food products using extracts obtained through green solvents is both innovative and promising. In pursuit of this goal, this study evaluated the possibility of directly fortifying spreadable chocolate with an optimized carotenoid-rich Natural Hydrophobic Deep Eutectic Solvent (NaHDES) extract formulated with monoterpenes. The optimized extract (3.545 ± 0.126, 3.341 ± 0.023, and 0.049 ± 0.001 mg/mL for total carotenoids, β-carotene and lutein, respectively) was obtained using a thymol/DL-menthol molar ratio of 1:4, a solvent:sample ratio of 10 (v/w), and an extraction time of 30 min. Subsequently, commercial no-sugar-added spreadable chocolate was fortified with the selected extract at 14 and 28 % (v/w). The fortified products were analyzed for carotenoid content, antioxidant activity, physicochemical and textural properties. The findings revealed that the lower extract addition minimally impacts the investigated characteristics of spreadable chocolate. Considering the preserving effect of the selected NaHDES on carotenoids and antioxidant activity, this innovative approach holds great promise for enhancing fortified food products' nutritional value and stability.
The preservation of perishable food items presents a significant challenge in the food industry. In this study, we investigated the development and characterization of chitosan-starch films incorporated with A. verum essential oil for application in grape preservation. The films were prepared using a solvent casting method, and their physical and antibacterial properties were thoroughly evaluated. The films demonstrated tensile strength values ranging from 21.28 MPa to 27.64 MPa and elongation at break between 71.24% and 84.23%. The water vapor permeability values for chitosan-starch films were from 2.04 kg/Pa·s·m to 2.51 kg/Pa·s·m. In addition, the antibacterial activity of the films was assessed against Escherichia coli and Staphylococcus aureus. The results revealed notable inhibitory effects, with inhibition zones ranging from 14.41 mm to 21.00 mm. The films' efficacy in grape preservation was evaluated through storage experiments at room temperature for 9 days, comparing them with polypropylene film and unwrapped samples. The chitosan-starch films, particularly those containing 1.0% A. verum essential oil, exhibited superior performance in reducing weight loss and maintaining grape firmness compared to common packaging materials. Moreover, grapes covered with these current active bio-based films demonstrated higher antioxidant activity, indicating potential benefits for extending shelf life and preserving fruit quality. Chitosan-starch films incorporated with A. verum essential oil hold promise as effective and environmentally friendly packaging materials for grape preservation.
Kidney stones, often resulting from a complex interplay of factors including oxalic acid, uric acid, and calcium. Current treatments lack comprehensive consideration of these factors and come with side effects. In this study, Lactobacillus paracasei GR-10 and Pediococcus acidilactici GR-11 were isolated from the fermented food “Jiangshui”. GR-10 demonstrated the ability to degrade 62.70% of oxalic acid (10 mM) within 24 h, while GR-11 degraded 28.60% of uric acid (4 mM). Combined treatment with GR-10 and GR-11 significantly reduced the number of stones in rats with ethylene glycol-induced kidney stones. This reduction was accompanied by a 57.19% decrease in urinary oxalate and a 52.80% decrease in serum uric acid levels. Simultaneously, urinary calcium level decreased by 27.18%. Inflammatory markers and indicators of oxidative stress associated with kidney stones were restored. Furthermore, the combined treatment effectively regulated the microbiota imbalance induced by kidney stones, resulting in reduced purine nucleoside accumulation in rat feces. This study offers promising insights into probiotics as an adjunct therapy for the prevention of kidney stones in the future.