Green Synthesis of Silver Nanoparticles Using Salvadora persica and Caccinia macranthera Extracts: Cytotoxicity Analysis and Antimicrobial Activity Against Antibiotic-Resistant Bacteria.

Silver nanoparticles (AgNPs) have gained great interest because of their specific and distinct properties. Chemically synthesized AgNPs (cAgNPs) are often unsuitable for medical applications due to requiring toxic and hazardous solvents. Thus, green synthesis of AgNPs (gAgNPs) using safe and nontoxic substances has attracted particular focus. The current study investigated the potential of Salvadora persica and Caccinia macranthera extracts in the synthesis of CmNPs and SpNPs, respectively. Aqueous extracts of Salvadora persica and Caccinia macranthera were prepared and taken as reducing and stabilizing agents through gAgNPs synthesis. The antimicrobial effects of gAgNPs against susceptible and antibiotic-resistant bacterial strains and their toxicity effects on L929 fibroblast normal cells were evaluated. TEM images and particle size distribution analysis showed that the CmNPs and SpNPs have average sizes of 14.8 nm and 39.4 nm, respectively. The XRD confirms the crystalline nature and purity of both CmNPs and SpNPs. FTIR results demonstrate the involvement of the biologically active substances of both plant extracts in the green synthesis of AgNPs. According to MIC and MBC results, higher antimicrobial effects were seen for CmNPs with a smaller size than SpNPs. In addition, CmNPs and SpNPs were much less cytotoxic when examined against a normal cell relative to cAgNPs. Based on high efficacy in controlling antibiotic-resistant pathogens without detrimental adverse effects, CmNPs may have the capacity to be used in medicine as imaging, drug carrier, and antibacterial and anticancer agents.

Olfactory Dysfunction in Patients Infected with 2019 Novel Coronavirus.

INTRODUCTION: The current study aimed at investigating the occurrence and features of olfactory dysfunction in patients with confirmed coronavirus disease 2019 (COVID-19) infection. MATERIALS AND METHODS: Patients with laboratory and clinically confirmed COVID-19 infection were enrolled in this longitudinal study. They were managed in either the inpatient or outpatient setting. The demographic, clinical, and outcome data were retrieved from patients' medical records. Olfactory dysfunction features, including the onset pattern, duration, and recovery time were investigated. The visual analog scale (VAS) was utilized as a self-rating subjective measurement of olfactory function. RESULTS: According to the results, the mean age of the patients (n=502) was obtained at 46.8±18.5 years; moreover, 52.4% and 47.6% of cases were female and male, respectively. It was also revealed that 35.4% and 64.5% of the subjects were outpatients and hospitalized, respectively. Based on the findings, 178 (38.4%) subjects had olfactory dysfunction. The mean values of VAS in hyposmic patients were estimated at 2.5±2.5, 8.3 ±2.1, and 9.4±1.6 at the first evaluation, in 2 weeks, and after 1 month of follow-up (P<0.001). The onset of olfactory dysfunction was more suddenly (58.7%). The majority of cases experienced olfactory dysfunction at the same time as other symptoms 72(51.1%). Based on the results, 0.4% of subjects infected with COVID-19 had olfactory dysfunction as an isolated symptom. The olfactory dysfunction was recovered after 2 weeks in 18 (25.3%) anosmic and 37(46.8%) hyposmic patients. CONCLUSION: Olfactory dysfunction seemed to be an important symptom of COVID-19 infection. The occurrence of this disturbance as a transient self-limited condition was significantly higher among female subjects.