Background: Conventional nanoparticle synthesis methods involve harsh conditions, high costs, and environmental pollution. In this context, researchers are actively searching for sustainable, eco-friendly alternatives to conventional chemical synthesis methods. This has led to the development of green synthesis procedures among which the exploration of the plant-mediated synthesis of nanoparticles experienced a great development. Especially, because plant extracts can work as reducing and stabilizing agents. This opens up new possibilities for cost-effective, environmentally-friendly nanoparticle synthesis with enhanced size uniformity and stability. Moreover, bio-inspired nanoparticles derived from plants exhibit intriguing pharmacological properties, making them highly promising for use in medical applications due to their biocompatibility and nano-dimension. Objective: This study investigates the role of specific phytochemicals, such as phenolic compounds, terpenoids, and proteins, in plant-mediated nanoparticle synthesis together with their influence on particle size, stability, and properties. Additionally, we highlight the potential applications of these bio-derived nanoparticles, particularly with regard to drug delivery, disease management, agriculture, bioremediation, and application in other industries. Methodology: Extensive research on scientific databases identified green synthesis methods, specifically plant-mediated synthesis, with a focus on understanding the contributions of phytochemicals like phenolic compounds, terpenoids, and proteins. The database search covered the field’s development over the past 15 years. Results: Insights gained from this exploration highlight plant-mediated green synthesis for cost-effective nanoparticle production with significant pharmacological properties. Utilizing renewable biological resources and controlling nanoparticle characteristics through biomolecule interactions offer promising avenues for future research and applications. Conclusion: This review delves into the scientific intricacies of plant-mediated synthesis of nanoparticles, highlighting the advantages of this approach over the traditional chemical synthesis methods. The study showcases the immense potential of green synthesis for medical and other applications, aiming to inspire further research in this exciting area and promote a more sustainable future.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an emergent infectious pathogen causing an acute respiratory disease called corona virus disease 2019 (COVID-19). Virus transmission may occur by contact, droplet, airborne or via contaminated surfaces. In efforts to effectively control the COVID-19 outbreak, the world health organization (WHO) and the Saudi Ministry of Health (MOH) have advised the public to practice protective measures to reduce transmission of the virus and reduce incidence of infection. These measures include hand washing, wearing masks and gloves and avoidance of touching the face with unwashed hands. The current study aimed to investigate knowledge and adherence of the Saudi population to these protective actions during the pandemic. After determining the required sample size using power analysis, a cross-sectional online self-reported survey of 5105 Saudi residents was conducted between 25^th March to 17^th April 2020 to evaluate public knowledge of COVID-19. Participants were all aged 18 years or above, Arabic speakers and residents of Saudi Arabia. Scores were calculated based on knowledge and adherence of the individuals to protective measures. About 90% of participants exhibited a high level of knowledge (scored 2/2) and practice (scored > 3/6) in relation to hand hygiene and wearing gloves and masks. Practice scores were positively associated with females and individuals with high income. Lower practice scores were linked to youth and residents of the northern and western regions of the Kingdom. Over two thirds of participants preferred hand washing to alcohol disinfection, and the frequency and performance of hand washing improved during the pandemic for more than half of respondents. Overall, the findings reflected high public knowledge of SARS-CoV2 transmission routes and adherence to personal protective measures. However, public awareness campaigns with an emphasis on the youth and individuals with low education and income are required to improve overall practice.

Secondary plant metabolites remain one of the key sources of therapeutic agents despite the development of new approaches for the discovery of medicinal drugs. In the current study, chemical analysis, and biological activities of Kei apple (Dovyalis caffra) methanolic extract were evaluated. Chemical analysis was performed using HPLC and GC–MS. Antiviral and anticancer effect were assessed using the crystal violet technique and activity against human liver cells (HepG2), respectively. Antibacterial activity was tested with the disc diffusion method. The obtained results showed that chlorogenic acid (2107.96 ± 0.07 µg/g), catechin (168 ± 0.58 µg/g), and gallic acid (15.66 ± 0.02 µg/g) were the main bioactive compounds identified by HPLC techniques. While, compounds containing furan moieties, as well as levoglucosenone, isochiapin B, dotriacontane, 7-nonynoic acid and tert-hexadecanethiol, with different biological activities were identified by GC–MS. Additionally, inhibition of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging was 79.25% at 2000 µg/mL, indicating its antioxidant activity with IC₅₀ of 728.20 ± 1.04 µg/mL. The tested extract exhibited potential anticancer activity (58.90% toxicity) against HepG2 cells at 1000 µg/mL. Potential bacterial inhibition was observed mainly against Escherichia coli and Proteus vulgaris, followed by Staphylococcus aureus and Bacillus subtilis with a diameter of growth inhibition ranging from 13 to 24 mm. While weak activities were recorded for fungi Candida albicans (10 mm). The extract showed mild antiviral activity against human coronavirus 229E with a selective index (SI) of 10.4, but not against human H3N2 (SI of 0.67). The molecular docking study's energy ratings were in good promise with the experiment documents of antibacterial and antiviral activities. The findings suggest that D. caffra juice extract is a potential candidate for further experiments to assess its use as potential alternative therapeutic agent.

Despite the advanced development in the field of drug discovery and design, fighting infectious and non-infectious diseases remains a major worldwide heath challenge due to the limited activity of currently used drugs. Nevertheless, in recent years, the approach of designing nanoparticles for therapeutic applications has gained more interest and promise for future use. Thus, the current study is focused on the evaluation of A. judaica extract and chitosan nanoparticles loaded extract (CNPsLE) for potential antimicrobial and anticancer activities. The HPLC analysis of the extract has shown the presence of various phenolic and flavonoid compounds, including kaempferol (3916.34 µg/mL), apigenin (3794.32 µg/mL), chlorogenic acid (1089.58 µg/mL), quercetin (714.97 µg/mL), vanillin (691.55 µg/mL), naringenin (202.14 µg/mL), and rutin (55.64 µg/mL). The extract alone showed higher MIC values against B. subtilis, E. coli, S. aureus, K. pneumonia, and C. albicans (62.5, 15.65, 15.62, 31.25, and 31.25 µg/mL, respectively), whereas lower MIC values were observed when the extract was combined with CNPsLE (0.97, 1.95, 3.9, 4.1, and 15.62 µg/mL, respectively). The extract exhibited low cytotoxicity against normal Vero cells with IC₅₀ 173.74 µg/mL in comparison with the cytotoxicity of the CNPsLE (IC₅₀, 73.89 µg/mL). However, CNPsLE showed more selective toxicity against the human prostate cancer cell line (PC3) with IC₅₀ of 20.8 µg/mL than the extract alone with 76.09 µg/mL. In the docking experiments, kaempferol and apigenin were revealed to be suitable inhibitors for prostate cancer (2Q7L). Overall, the obtained data highlighted the promising potential therapeutic use of CNPsLE as an anticancer and antimicrobial agent.

While it is reported that COVID-19 patients are more prone to secondary bacterial infections, which are strongly linked to the severity of complications of the disease, bacterial coinfections associated with COVID-19 are not widely studied. This work aimed to investigate the prevalence of bacterial coinfections and associated antibiotic resistance profiles among hospitalised COVID-19 patients. Age, gender, weight, bacterial identities, and antibiotic sensitivity profiles were collected retrospectively for 108 patients admitted to the intensive care unit (ICU) and non-ICU ward of a single center in Saudi Arabia. ICU patients (60%) showed a significantly higher percentage of bacterial coinfections in sputum (74%) and blood (38%) samples, compared to non-ICU. Acinetobacter baumannii (56%) and Klebsiella pneumoniae (56%) were the most prevalent bacterial species from ICU patients, presenting with full resistance to all tested antibiotics except colistin. By contrast, samples of non-ICU patients exhibited infections with Escherichia coli (31%) and Pseudomonas aeruginosa (15%) predominantly, with elevated resistance of E. coli to piperacillin/tazobactam and trimethoprim/sulfamethoxazole. This alarming correlation between multi-drug resistant bacterial coinfection and admission to the ICU requires more attention and precaution with prescribed antibiotics to limit the spread of resistant bacteria and improve therapeutic management.

Pyridine, 1,3,4-thiadiazole, and 1,3-thiazole derivatives have various biological activities, such as antimicrobial, analgesic, anticonvulsant, and antitubercular, as well as other anticipated biological properties, including anticancer activity. The starting 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-phenylthiourea (2) was prepared and reacted with various hydrazonoyl halides 3a–h, α-haloketones 5a–d, 3-chloropentane-2,4-dione 7a and ethyl 2-chloro-3-oxobutanoate 7b, which afforded the 3-aryl-5-substituted 1,3,4-thiadiazoles 4a–h, 3-phenyl-4-arylthiazoles 6a–d and the 4-methyl-3- phenyl-5-substituted thiazoles 8a,b, respectively. The structures of the synthesized products were confirmed by spectral data. All of the compounds also showed remarkable anticancer activity against the cell line of human colon carcinoma (HTC-116) as well as hepatocellular carcinoma (HepG-2) compared with the Harmine as a reference under in vitro condition. 1,3,4-Thiadiazole 4h was found to be most promising and an excellent performer against both cancer cell lines (IC₅₀ = 2.03 ± 0.72 and 2.17 ± 0.83 µM, respectively), better than the reference drug (IC₅₀ = 2.40 ± 0.12 and 2.54 ± 0.82 µM, respectively). In order to check the binding modes of the above thiadiazole derivatives, molecular docking studies were performed that established a binding site with EGFR TK.