Medicinal properties of selenium nanoparticles synthesized using leaf extracts of Passiflora incarnata and Cassia fistula and mechanistic exploration of antimicrobial effect

Background: Passiflora incarnata and Cassia fistula, both plants are well-known for their medical properties. To enhance these properties, they were used to synthesize Nanoparticles. Aim and Objectives: The aim of this project was to explore the medicinal properties of selenium nanoparticles (SeNPs) synthesized using the leaf extracts of Passiflora incarnata and Cassia fistula, an environmentally friendly and sustainable approach. This study investigated the antimicrobial potential of SeNPs and provided insights into the mechanisms behind their bactericidal activity. Material and Methods: The SeNPs were synthesized using aqueous leaf extracts of P. incarnata and C. fistula, with Polyvinyl Alcohol (PVA) as a stabilizing agent. Further characterization was performed using a UV spectrophotometer, dynamic light scattering (DLS), and zeta potential analysis. Synthesized SeNPs were tested for antioxidant, anti-diabetic, and antimicrobial activities. The potential mechanism underlying antimicrobial action, interactions between SeNPs and cellular biomolecules such as DNA and proteins, were also explored. Results: Brick red color formation indicated the synthesis of SeNPs. The biosynthesized SeNPs using P. incarnata exhibited an absorbance peak at 532 nm, and those using C. fistula exhibited an absorbance peak at 500 nm, with a Z-average mean particle size of 648.1 nm and a zeta potential of -1.41 mV. SeNPs displayed promising therapeutic properties, including notable antioxidant, anti-diabetic, and antimicrobial activities against bacterial and fungal pathogens. This study confirmed significant binding of SeNPs, without causing fragmentation of DNA or denaturation of proteins, suggesting that the antimicrobial effect may be mediated through non-destructive interactions that disrupt vital cellular processes. The absence of structural damage to biomolecules implies a unique mode of action that could minimize cytotoxicity to host cells. Conclusion: Overall, the results highlight the potential of SeNPs synthesized from P. incarnata and C. fistula as effective, biocompatible agents with multi-functional biomedical applications.