Green nanotechnology-based tellurium nanoparticles: Exploration of their antioxidant, antibacterial, antifungal and cytotoxic potentials against cancerous and normal cells compared to potassium tellurite

In this study, the antioxidant, antimicrobial, and cytotoxicity of mycosynthesized tellurium nanoparticles (TeNPs) were evaluated by using DPPH, microbroth dilution, and MTT tests, respectively. Interestingly, nanostructured tellurium (Te) represented strong antioxidant activity with IC50 of 20.66 µg/mL of elemental Te, while the IC50 of potassium tellurite was found to be 20 mM (equivalent to 2500 µg/mL of elemental Te). In addition, TeNPs did not exhibit good antibacterial and antifungal activity up to 250 µg/mL of elemental Te, however, higher concentrations of potassium tellurite exhibited antimicrobial potential. Furthermore, TeNPs represented more cytotoxicity against breast cancer MCF-7 cells with IC50 of 39.83 µg/mL after 48 h of treatment, while no IC50 was found against normal L929 cells up to 50 µg/mL after 48 h of treatment. Moreover, cytotoxic activity of the potassium tellurite against MCF-7 and L929 cells represented more cytotoxicity against L929 cells with IC50 of 76.33 µM (equivalent to 9.739 µg/mL of elemental Te) after 48 h of treatment, while no IC50 was found against MCF-7 cells up to 100 µM (equivalent to 12.76 µg/mL of elemental Te) after 48 h of treatment. Overall, the biogenic nanostructured Te exhibited higher antioxidant and anticancer activity compared to potassium tellurite.