TiO₂ nanoparticles functionalized with marigold for antioxidant role to enhance the skin protection

Nanotechnology captures great interest in various areas and has wide range of applications. Titanium dioxide (TiO₂) has been synthesized through different means such as physical, chemical, and green methods, whereas green synthesis of nanoparticles is a cost-effective, economical, non-toxic, and eco-friendly method, and TiO₂ nanoparticles have been used in cosmetic products as ultraviolet filters. Marigold (MG) being a strong antioxidant has been used for skin protection and contains anti-aging effects. In this study, MG-mediated TiO₂ nanoparticles (NPs) were biosynthesized, and bioactive compounds of this plant act as reducing and capping agents during the fabrication of nanoparticles. Characterization of NPs was done by using different techniques such as UV/Vis, XRD, and SEM. UV–visible absorption spectroscopy illustrated MG-TiO₂ NPs activity in visible light. X-ray diffractometry (XRD) confirmed the crystalline structure of TiO₂, and scanning electron microscopy (SEM) discovered the cylindrical shape of MG-TiO₂ NPs. The size of these NPs was found at 45.93 nm. MG extracts and NPs are analyzed for antioxidant activities, and MG nanoparticles showed strong antioxidant activity 50 µg/ml against DPPH. MG M and E also showed good oxidant scavenging activity. MG-TiO₂ NPs exhibited excellent results 82% against hydrogen mediated hemolysis in anti-hemolytic activity whereas MGM and MGE scavenge oxidants up to 74 and 73%. Cytotoxicity studies revealed that MG-NPs, MGM, and MGE extracts presented good results 23.42828 µg/ml, 25.14318 µg/ml, and 49.97482 µg/ml against brine shrimp assay and represent 86%, 40%, and 25% anticancer potential against hepG2 cell lines. Antibacterial activity of medicinal plants illustrated the highest inhibition zone against 24-mm Salmonella gallinarum for MG-TiO₂ NPs marigold methanol extract (MGM) and marigold ethanol extract (MGE) showing moderate antibacterial activity but no zones against Paeruginosa aeruginosa.