In this research, zinc oxide (ZnO) nanostructure was prepared by using zinc acetate (as precursor) and carboxylic derivative of activated carbon (as matrix). Activated carbon was modified by oxidation with nitric acid to get carboxylic derivative (AC-COOH). Then, zinc was loaded on the surface of modified activated carbon by an impregnation method. The ZnO nanostructure was characterized by BET, XRD and SEM that confirmed achieving of ZnO nanoparticles with a size of 21-31 nm and surface area of 17.78 m 2 gr −1. The efficiency of the catalyst was evaluated in the photocatalytic decomposition of aqueous solution of azo dye methyl orange (MO). Major parameters such as pH, dose of catalyst, stirring effect, initial concentration of dye and solution oxygen effect were considered. Activity measurements under UV radiation showed acceptable results for the photodegradation of MO. The efficiency of catalyst prepared with non-modified activated carbon for the photodegradation of MO was also evaluated. The results confirmed that ZnO prepared using carboxylic derivative of activated carbon as matrix had better photocatalytic activity than ZnO prepared by non-modified carbon matrix.

Objective: To report the chemical composition and bioactivity (including antioxidantand antimicrobial activity, hemolytic activities, and cytotoxicity) of flowers essential oil from Matricariachamomillavar. chamomilla(MCCO) for the first time. Methods: The essential oil was obtained using a Clevenger-type apparatus. Then, the essential oils composition was identified by chromatography methods. DPPH radical scavenging activity (RSA), β-carotene bleaching (BCB), and ferrous ion chelating ability (FIC) were chosen to evaluate the MCCO antioxidant activity. Disc diffusion assay and minimum inhibitory concentration method (MIC) were chosen to investigate antibacterial activity of MCCO. Hemolytic activity of MCCO on red blood cells (RBCs)was evaluated through optical density. MTT method was used to determine the cytotoxicityeffects of MCCO on human cancer cells. Results: MCCO was dominated by oxygenated sesquiterpenes (59.01%). α-Bisabolone oxide A (35.74%), α-Bisabolol oxide A (19.07%), (Z)-β-Farnesene (6.63%), and Chamazulene (6.46%) was found as the major components of essential oil. The oil represented an acceptable antioxidant activity. For antibacterial activity, MCCO prevented the growth of 6 out of 7 selected microorganisms. MCCO was just inactive against Staphylococcus coagulase. The low hemolytic rate (below 1.5%) of MCCO on RBCs proposed its safety. Conclusions: An oxygenated sesquiterpene namely α-bisabolone oxide A was recognized as the main compound of MCCO. The oil can be considered as a strong antibacterial agent as well as an antioxidant. The safety of MCCO as a food additive or other uses was suggested by hemolysis results. MCCO was identified as a weak agent in the cytotoxicity assay.

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: Viral infection is a worldwide health problem, which has negatively affected global activity in recent years. There is no specific medication for most viral infections, and the treatments are based on symptom management. Nanoparticles (NPs) in recent years have shown promising antibacterial and antiviral properties, among which metal oxide NPs have shown superiority. In the present study, we aimed to systematically review all available literature supporting the efficiency of zinc oxide (ZnO) NPs in the treatment of viral infections. For this purpose, a systematic literature search was performed in scientific literature databases including PubMed, Scopus, Web of Science, Science Direct, Ovid, Embase, and Google Scholar by using “viral infections”, “antiviral effects,” and “ZnO NPs” in addition to all their equivalent terms as keywords. Due to the lack of human studies, no strict inclusion criteria were defined, and all available relevant literature were included. A total of 14 documents that fully met the inclusion criteria were retrieved and used for data synthesis. The results showed that ZnO NPs, due to some specific physiochemical properties, can be a promising approach in developing antiviral agents and nanovaccines, especially against RNA viruses, such as human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus. The most probable antiviral mechanistic pathways of ZnO NPs were blocking the virus entry into the cells and deactivation of the virus through virostatic potential. Based on the findings of the included studies, it is suggested that ZnO NPs and other metal oxide-based NPs may be a potential antiviral agent; however, further human studies are required to confirm such efficiency in clinical practice.

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