Cytotoxic activity of silver nanoparticles prepared from Psidium guajava L. (Myrtaceae) and Lawsonia inermis L. (Lythraceae) extracts

Purpose: To biosynthesize silver nanoparticles (AgNPs) using Psidium guajava L. and Lawsonia inermis L. leaf extracts, and investigate their antioxidant and cytotoxic activities. Methods: The aqueous extracts were prepared by maceration in distilled H2O followed by partitioning with EtOAc. AgNPs were prepared by treating the extracts with 1 mM AgNO3 and then were characterized by UV-vis and FTIR analyses, and transmission electron microscopy (TEM). MTT cytotoxicity and 2,2`-azinobis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) antioxidant assays were used to assess their cytotoxic and antioxidant properties, respectively. Results: AgNPs from P. guajava and L. inermis extracts exhibited good morphological stability and showed moderate antioxidant activity (68.1 and 71.9%, respectively) compared to their extracts. Equipotent cytotoxicity against HCT-116 and MCF-7 cells was observed for AgNPs derived from P. guajava, while AgNPs derived from L. inermis possessed two-fold cytotoxicity compared to their corresponding extracts. Phytochemical analysis of P. guajava afforded pyrogallol, quercetin, quercetin3-O-3-xylopyranoside, quercetin-3-O-3-arabinopyranoside, and quercetin-3-O-alpha-arabinofuranoside, while L. inermis afforded lawsone and luteolin. Conclusion: Flavonoids and phenolics play a major role in reducing Ag+ ions, surface coating, antioxidant, and cytotoxic activities of AgNPs. The biocompatible AgNPs produced by L. inermis demonstrate promising cytotoxic activity that could contribute to new cancer treatments.

Automated summary

The study demonstrated that silver nanoparticles biosynthesized using Psidium guajava and Lawsonia inermis leaf extracts exhibited potent cytotoxicity against colon cancer cells and breast cancer cells, with higher cytotoxicity observed for nanoparticles derived from Lawsonia inermis. Additionally, the nanoparticles showed moderate antioxidant activity compared to their respective extracts.