Optimization and evaluation for biomedical activities of green-synthesized cobalt oxide nanoparticles using Astrodaucus persicus and their novel sunscreen applications

In recent years, the global need for sustainable nanotechnological approaches has arisen due to the strong concern about drug-resistant microorganisms and water pollution being a major problem. In this study, Astrodaucus persicus was used for the green synthesis of cobalt oxide nanoparticles (A@CoONPs), as high-performance liquid chromatography (HPLC) confirmed the presence of key phytochemicals such as p-coumaric acid (9.63 mg/g) and rutin (7.38 mg/g), which can act as natural reducing and stabilizing agents during nanoparticle formation. The nanoparticles were characterized using various analytical techniques. The antibacterial, anticancer, free radical scavenging, water purification performance organic dye degradation and heavy metal removal, colorimetric sensor, and sunscreen properties (first-time) of the synthesized nanoparticles were evaluated. A@CoONPs demonstrated potent antibacterial effects against a broad spectrum of bacterial strains. They exhibited notable anticancer activity against AGS cancer cell lines (IC₅₀ = 66.61 µg/ml) and lower cytotoxicity toward normal L929 cells (IC₅₀ = 330.35 µg/ml), resulting in a 4.96-fold higher selectivity index compared to cisplatin. The nanoparticles could also degrade organic dyes, facilitate the removal and detection of heavy metal ions. Also, the nanoparticles exhibited a sun protection factor (SPF) of 22.66 at a concentration of 1 mg/ml. Collectively, these results promise broad applications of green-synthesized A@CoONPs for medical, environmental, sensing, and cosmetic applications.