Selenium nanoparticles stabilized in tannic acid: An innovative approach for combating infections caused by H. pylori or candida albicans

Selenium is an essential trace elemental in the diet, required for maintenance of health and growth. Give that the least toxic form of selenium is elemental Se, its nano-form has attracted significant attention. In recent years, selenium nanoparticles (SeNps) attracted the interest of many researchers due to their biocompatibility, bioavailability and low toxicity. Several studies have pointed out the ability of SeNps to exhibit anticancer, antioxidant, antibacterial and anti-biofilm properties. So far, remarkable antimicrobial activity of these nanoparticles have been evidenced against pathogenic bacteria, fungi and yeasts. The recent boom in nanotechnology furnished and indefinite number de applications of metal nanoparticles in biomedicine. Metal nanoparticles, for example, gold and silver, have immense medicinal benefits but are costlier to synthesis, whereas the synthesis of SeNps is economical and they can be integrated with other biological agents to enhance their biological properties. The synthesis of SeNps by various methods has been reported. These methods are divided two categories, namely biological and chemical reduction. The chemical reduction method uses chemical reducing agents, energy sources and apparatus to carry out the reaction. So far, SeNps have been synthesized in various forms such as nanowires, nanorods and nanotubes through sonochemical, microwave, hydrothermal methods. In this study, we discuss the synthesis of SeNps using tannic acid as reducing and stabilizing agent, and explores their potential as a novel strategy against bacterial (H. pylori) and fungal (Candida albicans) infections. Tannic acid, a plant derived polyphenolic compound, is one such agent which embodies characteristics of being harmless and environmentally friendly combined with being a good reducing and stabilizing agent, these gives an eco-friendly agent to the green synthesis of SeNps. The synthesis of monodisperse SeNps by tannic acid was conducted under slightly basic conditions (pH=8). The characteristic absorption peak of the SeNps appearance of a sharp peak at 265 nm. The DRX pattern show the reflections corresponding to metallic Se. In humans, fungal and bacterial infections are responsible for causing a wide range of diseases to life-threatening. Infections caused by Helicobacter pylori (H. pylori), a Gram-negative microaerobic bacterium that colonizes the human stomach, it has been associated with gastrointestinal diseases including chronic gastritis, peptic ulcer, gastric carcinoma. On the other hand, Candida albicans is the most common pathogenic fungus that affects the oral cavity, skin, reproductive tract, and gastrointestinal tract. These microbial infections that cause great health concerns are due that most of the pathogenic organisms have become drug-resistant because of the constant utilization of a wide range of antibiotics. The frequency percent of Minimun Bactericidal Concentration (MIC) (μg/mL) of SeNps in clarithromycinsensitive and resistant H. Pylori isolates was determined. SeNPs showed antibacterial activity against both clarithromycin sensitive and resistant H. Pylori isolates with MIC values of 2.9 - 370 μg/mL. The dispersion of the MIC of SeNPs in clarithromycin sensitive isolates was 37.5 ug/ml and in clarithromycin resistant isolates was 37.5 to 92.5 ug/mL. This results demonstrate the potential of SeNps as novel antimicrobial agents for the treatment of diseases caused by H. pylori and candida albicans.