## 1 _Article_  
Green Synthesis of Gold Nanoparticles by Aqueous Extract of _Zingiber officinal_: Characterization and Insight into Antimicrobial, Antioxidant, and In Vitro Cytotoxic Activities  
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involve a combination of cytotoxic agents such as alkylating agents and anti-metabolic agents. Unfortunately, improper application of chemotherapy leads to the development of multidrug resistance and causes patients to suffer severe side effects. This requires the development of new treatments. Biologically active ingredients such as plant extracts and natural dietary ingredients associated with nanomaterials have been revealed as promising alternatives [2; 3]. Nanoparticles (NPs) are the basic building block of nanotechnology and have at least one dimension in the nanometric scale range of 1-100 nm. These materials have unique chemical, physical, and mechanical properties that justify their application in many fields, such as agriculture, wastewater treatment, textile industry, energy, catalysis, adsorption of heavy metals, medicine, and cosmetics [4; 5]. For instance, silver nanoparticles (AgNPs) fabricated by root extract of _Helicteres ison_ exhibit antibacterial and antioxidant activities [6]. High antibacterial activity was obtained against Gram-negative bacteria (_Salmonella typhi_ and _Pseudomonas aeruginosa_) compared with Gram-positive bacteria (_Bacillus subtilis_ and _Microoccus luteus_). Moreover, synthesized AgNPs showed promising antioxidant activity, which was characterized by the DPPH method, a reducing power assay, and scavenging of nitric oxide radicals and hydrogen peroxide. In a recent study, selenium nanoparticles (SeNPs) synthesized by harnessing an aqueous extract of _Portulaca oleracea_ showed antimicrobial, antiviral cytotoxicity in vitro, as well as mosquitocidal activities [7]. Nanomaterials and nanocolloids can be manufactured by physical, chemical, and biological methods [8]. The biofabrication of nanomaterials using extracts of plants and microorganisms is very interesting for avoiding pressures, high temperatures, and hazardous chemicals. The high stability of green synthesized nanomaterials is associated with the capping effect of the plant extract [9; 10; 11]. Moreover, the technique is environmentally friendly and biologically safe, as well as being low-cost [12; 13]. Among the various biological methods for the production of nanoparticles, plants are very attractive for green synthesis due to their diversity and ease of use. In addition, plant extracts contain a large number of phytochemicals that may combine different roles, such as reducing and/or stabilizing agents for the production of nanomaterials [14; 15; 16; 17]. Biogenic NPs have been adapted and applied in many important fields of biotechnology, such as tissue engineering, health and medicine, drug delivery, pharmacology, cosmetics, nanolagnostics, and agriculture [18; 19]. Recently, gold NPs have become a topic of interest due to their volumetric and morphological properties that can be modulated by their electrical, optical, physical, and chemical characteristics. These particles have been used in many technological applications, such as optoelectronics, nanoelectronics, and biological and chemical sensors, in addition to their biomedical applications in controlled drug delivery and release and bioimaging [20]. Moreover, gold NPs exhibit outstanding sensitivity and selectivity for the colorimetric identification of toxic heavy metal ions [21]. In this context, nanogram doses of gold NPs manifested potential activity against multidrug-resistant pathogens, as well as against _Candida albicans_; therefore, they were employed as a coating for medical devices [22]. Owing to their low toxicity, AuNPs were used in oral biology and for the coating of urological catheters [22]. AuNPs may reduce nosocomial infections [23].