Nano-cubosomes of the phyto-active principle in Withania somnifera: LC-MS-NMR, anti-microbial, and insights of the anti-neuropathic and anti-inflammatory mechanism.

Withania somnifera (W. somnifera) has a long history of safety in the amelioration of neuro-active ailments. The current study aims to explore Withania somnifera phyto-active principle anti-microbial, ant-neuropathic, and anti-inflammatory activities, and to modify these activities utilizing nano-cubosomes exploiting their mechanisms of action. Bio-guided fractionation technique was utilized, to identify the most phyto-active compound, using LC-MS-NMR online technique and biological models of diabetes, neuropathy, and inflammation. In-vitro antibacterial activity was also monitored. The HbA1c, in-vivo antioxidant (serum-catalase, TBARS, and GSH), serum insulin, and pro-inflammatory serum cytokines (TNF alpha, IL-six, and IL-ten) levels have been assessed to establish the anti-neuropathic and anti-inflammatory mechanisms. The nano-cubosomal formulations (CUB 1-3) were utilized to improve the W. somnifera most active compound efficacy. W. somnifera has shown ten major peaks; coagulin Q (10.2 %), dihydrowithanolide A (2.4 %), dihydrowithaferin D (1.8 %), physagulin D (7.6 %), withanoside V (2.3 %), withanolide A (WDA, 10.3 %), withafrin A (4.9 %), withaferin D (7.7 %), withanone 9 (9.9 %), withanolide D (4.8 %). The bio-guided fractionation technique utilizing LC-MS-NMR technique has proved that withanolide A (WDA) is the most phyto-active compound in W. somnifera. The latter has shown better results than WDA, which might be due to other effective compounds in Ws. However, CUB 3 (WDA nano-cubosomes dispersion) has shown more prominent anti-diabetic, anti-neuropathic, anti-inflammatory, and anti-bacterial potentials than Ws and WDA. Thus, CUB 3 modified WDA activity, and improved its efficacy. The normalization of HbA1c levels, increased insulin secretagogue potential, and the amelioration of the oxidative-stress may be the underlying Ws, WDA, and CUB 3 antidiabetic neuropathy mechanism. Moreover, the Ws, WDA, and CUB 1-3 anti-inflammatory mechanism might be due to the amelioration of the pro-inflammatory serum cytokines (decreasing TNF alpha and IL-six levels and increasing IL-ten). Thus, CUB 3 might be a powerful tool in augmenting Withania somnifera activity as an oral drug-delivery system and improving its efficacy against neuropathy and inflammation.

Antibacterial and antibiofilm activities of diclofenac against levofloxacin-resistant Stenotrophomonas maltophilia isolates; emphasizing repurposing of diclofenac.

Background and Objectives: Stenotrophomonas maltophilia is an opportunistic pathogen causing nosocomial infections. Diclofenac is an anti-inflammatory drug that is considered a non-antibiotic drug. This study assessed the antibacterial and antibiofilm effects of diclofenac and levofloxacin/diclofenac combination against levofloxacin resistant isolates. Materials and Methods: Minimum inhibitory concentration was determined using broth microdilution method for levofloxacin, diclofenac, and levofloxacin/diclofenac combination. Biofilm forming capacity and biofilm inhibition assay were determined. Relative gene expression was measured for efflux pump genes; smeB, and smeF genes and biofilm related genes rmlA, spgM, and rpfF without and with diclofenac and the combination. Results: Diclofenac demonstrated MIC of 1 mg/ml. The combination-with ½ MIC diclofenac-showed synergism where levofloxacin MIC undergone 16-32 fold decrease. All the isolates that overexpressed smeB and smeF showed a significant decrease in gene expression in presence of diclofenac or the combination. The mean percentage inhibition of biofilm formation with diclofenac and the combination was 40.59% and 46.49%, respectively. This agreed with biofilm related genes expression investigations. Conclusion: Diclofenac showed an antibacterial effect against Stenotrophomonas maltophilia. The combination showed in-vitro synergism, significant reduction in biofilm formation and in the relative level of gene expression. Furthermore, it can potentiate the levofloxacin activity or revert its resistance.

Anti-Spike and Neutralizing Antibodies after Two Doses of COVID-19 Sinopharm/BIBP Vaccine.

Host response to COVID-19 vaccines is partially evaluated through the estimation of antibody response, specifically the binding anti-spike (anti-S) and the neutralizing antibodies (nAbs) against SARS-CoV-2. Vaccine-induced humoral response affects decisions on the choice of vaccine type, vaccine acceptance, and the need for boosting. Identification of risk factors for poor antibody response helps to stratify individuals who might potentially require booster doses. The primary objective of this cross-sectional study was to investigate the antibody response after receiving two Sinopharm vaccine doses. Factors affecting antibody response were additionally studied. Moreover, a predictive cutoff for anti-S was generated to predict positivity of nAbs. Blood samples were collected from 92 adults and relevant data were recorded. Antibody levels (anti-S and nAbs) against SARS-CoV-2 were tested one month following the second dose of Sinopharm vaccine using two commercial ELISA tests. Among the 92 participants, 88 tested positive for anti-S (95.7%), with a median level of 52.15 RU/mL (equivalent to 166.88 BAU/mL). Fewer participants (67.4%) were positive for nAbs, with a median percentage of inhibition (%IH) of 50.62% (24.05−84.36). A significant positive correlation existed between the titers of both antibodies (correlation coefficient = 0.875, p < 0.001). When the anti-S titer was greater than 40 RU/mL (128 BAU/mL), nAbs were also positive with a sensitivity of 80.6% and a specificity of 90%. Positive nAbs results were associated with a higher anti-S titers (62.1 RU/mL) compared to negative nAbs (mean anti-S titer of 18.6 RU/mL). History of COVID-19 infection was significantly associated with higher titers of anti-S (p = 0.043) and higher IH% of nAbs (p = 0.048). Hypertensive participants were found to have significantly higher median titers of anti-S (101.18 RU/mL) compared with non-hypertensive ones (42.15 RU/mL), p = 0.034. Post-vaccination headache was significantly higher among those with higher anti-S than those with relatively lower titers (98.82 versus 43.69 RU/mL, p = 0.048). It can be concluded that the Sinopharm vaccine produced high levels of binding antibodies but with low neutralizing abilities. Also, levels of anti-S titer greater than 40 RU/mL could adequately predict positivity of nAbs without need for their testing.

Nanophyto-gel against multi-drug resistant Pseudomonas aeruginosa burn wound infection.

Burn wound is usually associated by antibiotic-resistant Pseudomonas aeruginosa infection that worsens and complicates its management. An effective approach is to use natural antibiotics such as cinnamon oil as a powerful alternative. This study aims to investigate topical nanostructured lipid carrier (NLC) gel loaded cinnamon oil for Pseudomonas aeruginosa wound infection. A 24 full factorial design was performed to optimize the formulation with particle size 108.48 ± 6.35 nm, zeta potential -37.36 ± 4.01 mV, and EE% 95.39 ± 0.82%. FTIR analysis revealed no excipient interaction. Poloxamer 407 in a concentration 20% w/w NLC gel was prepared for topical application. Drug release exhibited an initial burst release in the first five hours, followed by a slow, sustained release of up to five days. NLC-cinnamon gel has a significant ability to control the drug release with the lowest minimum inhibitory concentration again P. aeruginosa compared to other formulations (p < .05). In vivo study also showed NLC-cinnamon gel effectively healed the infected burned wound after a six-day treatment course with better antibacterial efficacy in burned animal models. Histological examination ensured the tolerability of NLC-cinnamon gel. The results suggest that nanoparticle-based cinnamon oil gel is a promising natural product against antibiotic-resistant strains of P. aeruginosa in wound infection.

Synthesis, antibacterial evaluation, and DNA gyrase inhibition profile of some new quinoline hybrids.

Antibiotic-resistant bacteria continue to play an important role in human health and disease. Inventive strategies are necessary to develop new therapeutic leads to challenge drug-resistance problems. From this perception, new quinoline hybrids bearing bioactive pharmacophores were synthesized. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against nine bacterial pathogenic strains. The results revealed that most compounds exhibited good antibacterial activities. Seven compounds (2b, 3b, 4, 6, 8b, and 9c,d) displayed enhanced activity against methicillin-resistant Staphylococcus aureus compared to ampicillin. These compounds were subjected to an in vitro S. aureus DNA gyrase ATPase inhibition study, which revealed that compounds 8b, 9c, and 9d showed the highest inhibitory activity with IC50 values of 1.89, 2.73, and 2.14 µM, respectively, comparable to novobiocin (IC50 , 1.636 µM). Compounds 2a-c, 3a, 7c, 9c,d, and 10a,b revealed half the potency of levofloxacin in inhibiting the growth of Pseudomonas aeruginosa. As an attempt to rationalize the observed antibacterial activity for the most active compounds 8b, 9c, and 9d, molecular docking in the ATP binding site of S. aureus gyrase B was performed using Glide. Such compounds could be considered as promising scaffolds for the development of new potent antibacterial agents.

Synthesis and molecular docking study of some 3,4-dihydrothieno[2,3-d]pyrimidine derivatives as potential antimicrobial agents.

In continuation of our research program aiming at developing new potent antimicrobial agents, new series of substituted 3,4-dihydrothieno[2,3-d]pyrimidines was synthesized. The newly synthesized compounds were preliminary tested for their in vitro activity against six bacterial and three fungal strains using the agar diffusion technique. The results revealed that compounds 7, 8a, 10b, 10d and 11b exhibited half the potency of levofloxacine against the Gram-negative bacterium, Pseudomonas aeruginosa, while compounds 5a, 8b, 10c and 12 displayed half the potency of levofloxacine against Proteus Vulgaris. Whereas, compounds 7, 10b, 10d and 11b showed half the activity of ampicillin against the Gram-positive bacterium, B. subtilis. Most of the compounds showed high antifungal potency. Compounds 3, 6, 7, 9b, 10a, 11a, 11b, 15 and 16 exhibited double the potency of clotrimazole against A. fumigatus. While compounds 3, 4, 5a, 5b, 9b, 10a, 10b, 10c, 13, 15, 16 and 18 displayed double the activity of clotrimazole against R. oryazae. Molecular docking studies of the active compounds with the active site of the B. anthracis DHPS, showed good scoring for various interactions with the active site of the enzyme compared to the co-crystallized ligand.

Synthesis of pyrazolo-1,2,4-triazolo[4,3-a]quinoxalines as antimicrobial agents with potential inhibition of DHPS enzyme.

AIM: The development of a new class of antimicrobial agents is the optimal lifeline to scrap the escalating jeopardy of drug resistance. EXPERIMENTAL: This study aims to design and synthesize a series of pyrazolo-1,2,4-triazolo[4,3-a]quinoxalines, to develop agents having antimicrobial activity through potential inhibition of dihyropteroate synthase enzyme. The target compounds have been evaluated for their in-vitro antimicrobial activity. RESULTS & DISCUSSION: Compounds 5b, 5c were equipotent (minimal inhibitory concentration = 12.5 µg/ml) to ampicillin. The docking patterns of 5b and 5c demonstrated that both fit into Bacillus Anthracis dihydropteroate synthase pterin and p-amino benzoic acid-binding pockets. Moreover, their physicochemical properties and pharmacokinetic profiles recommend that they can be considered drug-like candidates. The results highlight some significant information for the future design of lead compounds as antimicrobial agents.

Design, synthesis, antibacterial evaluation and molecular docking studies of some new quinoxaline derivatives targeting dihyropteroate synthase enzyme.

Development of new antimicrobial agents is a good solution to overcome drug-resistance problems. From this perspective, new quinoxaline derivatives bearing various bioactive heterocyclic moieties (thiadiazoles, oxadiazoles, pyrazoles and thiazoles) were designed and synthesized. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against nine bacterial human pathogenic strains using the disc diffusion assay. In general, most of the synthesized compounds exhibited good antibacterial activities. The thiazolyl 11c displayed significant antibacterial activities against P. aeruginosa (MIC, 12.5 µg/mL vs levofloxacin 12.5 µg/mL). Molecular docking studies indicated that the synthesized compounds could occupy both p-amino benzoic acid (PABA) and pterin binding pockets of the dihydropteroate synthase (DHPS), suggesting that the target compounds could act by the inhibition of bacterial DHPS enzyme. The results provide important information for the future design of more potent antibacterial agents.