Anti-proliferative and biocidal effect of watermelon (Citrullus lanatus) seed extract and its nanoformulation

[Display omitted] •A facile and green synthesis of nanoparticles of Watermelon seeds is proposed.•No chemical precursors or surfactants were used.•The nanoparticles exhibited profound antibacterial and antiproliferative activity.•It is a potential novel nutraceutical with a prospective role in cancer therapy. Watermelon (Citrullus lanatus) seeds are endowed with phytonutrients that ascribe to their potent antioxidant status. The present study proposes a facile and novel green synthesis of nanoparticles of the seed extract. The synthesized nanoparticles showed a mean average size of 215 nm with a single significant peak and a polydispersity index (PDI) of 0.11.The electron micrographs showed spherical nanoparticles dispersed without agglomeration The biocidal and the antiproliferative effect on cancer cell lines (HCT-116, HepG-2, HeLa) of the nanoparticles (WMnano) was more pronounced as compared to the bulk seed extract (WMS).