Silver Nanoparticles from Saudi and Syrian Black Cumin Seed Extracts: Green Synthesis, ADME, Toxicity, Comparative Research, and Biological Appraisal.

Objective: The current study's objective is to highlight the value of using plant resources to identify key bioactive molecules and implement green chemistry in research and development to meet market demand. Materials and Methods: The black cumin seeds (Saudi and Syria originated) were utilized to make silver nanoparticles (Ag-NPs), which were subsequently confirmed using a UV spectrophotometer and color analysis of reaction mixtures. The antibacterial activity of Ag-NPs was tested against E. coli, K. pneumoniae, and S. aureus, and antioxidant activity was measured using the DPPH assay. Swiss-ADME, pkCSM, and ProTox-II were also used to assess the pharmacokinetics, oral bioavailability, toxicity, and safety endpoints of molecules. Result: The antibacterial effect of Ag-NPs from Saudi-origin black cumin seeds was observed higher. In comparison to the standard, the Saudi and Syrian Ag-NPs combined displayed synergistic antibacterial effects and were found to be more susceptible to S. aureus. In comparison to the reference, the antioxidant activity of Ag-NPs indicated 60-85% radical scavenging. All molecules passed the Lipinski rule, the filter (Veber, Egan, and Muegge), PAINS, and the Brenk structural alert (zero violations), and the synthetic score was also found to be in the easy limit (1 to 2). The compounds were found to be non-substrate for p-glycoprotein, high GIA% (>90%), non-inhibitor for CYP3A4, CYP2C19, CYP2C9, CYP2D6 (except 5 and 10), Log Po/w (1.71 to 3.26), TPSA 150 2 and MR 155. The compounds likewise had high Caco2 values (log Papp >0.9) with the exception of 4 and 9 (log Papp 0.9), were non-inhibitors of P-gp-I and II and hERG I and II, and showed no AMES toxicity. Except for molecule 11, no organ damage (hepatotoxicity) or endpoint toxicity (mutagenicity, immunotoxicity, carcinogenicity, and cytotoxicity) was identified in ProTox-II. Conclusion: The current study sheds new light on the significance of bioactive molecules found in black cumin seeds, with molecules 3 and 6 identified as potential leads (highest GIA%, no AMES toxicity, oral rat acute and chronic toxicity, lack of renal OCT2 substrate, high total clearance, and lack of organ toxicity) for further research for a variety of medical applications.

Synthesis of magnetic iron oxide nanoparticles using pulp and seed aqueous extract of Citrullus colocynth and evaluation of their antimicrobial activity.

OBJECTIVES: Citrullus colocynth (CTC) is a wild medicinal plant with proven antimicrobial activity. The aim of this study is to investigate the use of its aqueous extract in producing magnetic iron oxide nanoparticles (MNPs) with improved antimicrobial activity. The cold and hot aqueous extract of seed and pulp parts of CTC, respectively, were used to produce MNPs. The particles were characterized by transmission electron microscope, energy dispersion x-ray, FTIR and their surface charge were measured. The antimicrobial activity of the produced particles was assessed against two Gram positive (Bacillus subtillis and Staphylococcus aureus) and two Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and well as against Candida albicans. RESULTS: MNPs synthesized using cold seed extract (S-MNP) and pulp extract (P-MNP) were spherical in shape. The size distribution was more uniform in the S-MNP (6-15 nm) compared to the P-MNP (12-45 nm). Both particles showed comparable anti-microbial potential against the tested microorganisms. At a concentration range of 0.48-1000 µg/mL, S-MNP inhibited bacterial growth by 16.0-99.0% and 10.0-91.0%; while P-MNP inhibition was 11.0-100.0% and 11.0-99.0% for Gram positive and negative bacteria; respectively. Candida albicans was the least affected microorganism with maximum inhibition of 63-88% after treatment with S-MNP and P-MNP (1 mg/mL), respectively. CONCLUSIONS: The aqueous extract of CTC can be used for synthesis of MNPs with antimicrobial activity. The described procedures are simple and can be modified for large scale green synthesis of MNPs.

Salmonella isolates serotypes and susceptibility to commonly used drugs at a tertiary care hospital in Riyadh, Saudi Arabia.

INTRODUCTION: Resistance of Salmonella to therapeutic agents currently being used for treatment of Salmonella infections is emerging as a global problem. This study aimed to assess the prevalence of Salmonella serotypes and their susceptibility patterns to commonly used drugs for treatment of Salmonella infections including quinolones. Correlation between nalidixic acid susceptibility of these isolates and their ciprofloxacin minimum inhibitory concentrations was also sought. METHODOLOGY: Salmonella isolates (n=213) were collected between January 2007 and May 2009 at King Khalid University Hospital in Riyadh, Saudi Arabia. The isolates were serotyped and their susceptibilities to commonly used first-line anti-Salmonella drugs (ampicillin, ceftriaxone, trimethoprim/sulfamethoxazole, nalidixic acid and ciprofloxacin) were determined using the automated Microscan system, the Kirby-Bauer disk diffusion method, and E-test. RESULTS: The most frequently detected serotype was D1 (37%) followed by the serotypes, B (24%) and C1 (11%). Non-typable Salmonella isolates detected using available conventional Salmonella anti-sera were (11%). Overall resistance rates to nalidixic acid, ampicillin, trimethoprim/sulfamethoxazole and ceftriaxone were 99/213 (46%), 43/213 (20%), 34/213 (16%) and 7/213 (3%), respectively. Of the total isolates, 117 (55%) had a ciprofloxacin MIC of <0.125 µg/ml and among these 105 (90%) were susceptible to nalidixic acid. The remaining 96 (45%) isolates had a ciprofloxacin MIC of ≥ 0.125 µg/ml and among them, 83 (86.5%) were resistant to nalidixic acid. CONCLUSIONS: The majority of Salmonella isolates in this study were non-typhi serotypes. Significantly higher proportions of Salmonellae were resistant to nalidixic acid and ciprofloxacin and a vast majority of nalidixic acid resistant organisms exhibited decreased susceptibility to ciprofloxacin.