One-pot green synthesis of platinum nanoparticles (Pt-NPs) using Sargassum polyphyllum extract displays nanodrug prospects against human cervical, breast, and colon cancer cells

Fabrication of nanoparticles (NPs) via green method has superseded the chemical procedures owing to its inherent features of biocompatibility and environment safety. From this perspective we used Sargassum polyphyllum, a marine brown macroalgae, preserving unique phytochemicals and growing under stress-tolerant environmental settings. We aimed for synthesizing platinum NPs (Pt-NPs) using extracellular extract of S. polyphyllum and evaluated its in vitro anticancer efficacy against human breast (MCF-7), cervical (HeLa), and colon (HT-29) cancer cells. Pt-NPs formation confirmed by color change with simultaneous disappearance of SPR band at 258.4 nm. TEM and SEM analysis exhibited rough surfaced aggregated clusters of pleomorphic spheroidal particles having an average size of 4.7 ± 0.01 nm. The hydrodynamic properties of Pt-NPs showed small (90.65 d.nm) and large (367.7 d.nm) peaks in DLS and a zeta (ζ)-potential of −43.6 mV. MTT and NRU assays exhibited cytotoxic effects in MCF-7, HeLa, and HT-29 cells after Pt-NPs exposure for 24 h. Flow cytometric analysis of Pt-NPs-treated cells caused dysfunction of mitochondrial membrane potential (ΔΨm), greater levels of intracellular ROS, NO, esterase, and Ca²⁺ influx. Pt-NPs induced nuclear DNA damage and triggered apoptotic cell death in the cancer cells. Subsequently immunofluorescence has affirmed cytoplasmic localization of p53 in Pt-NPs treated cancer cells. qPCR array of 84 genes demonstrated the activation of myriad genes pertaining to human cancer pathway in the exposed cells. On the whole Pt-NPs has demonstrated its anticancer efficacy in the order of HeLa>MCF-7 > HT-29 cells indicating its prospective as a nanodrug derived through eco-friendly approach.