RETRACTED: Green synthesis of gold nanoparticles using Benincasa hispida and evaluation of its anticancer activity against oral cancer cell line

Abstract

Background Benincasa hispida, a commonly used vegetable in India and other tropical countries, is known for its nutritional and medicinal values. The gold nanoparticles synthesis (AuNPs) using phytochemicals has gained importance for its enhanced biocompatibility and bioactivity in biomedical applications. India has high incidence of oral cancer in the world due to high prevalence of tobacco chewing. The study evaluated the phytosynthesis of AuNPs from the aqueous extract of B. hispida and assessed its anticancer potential in KB oral cancer cell line. For the synthesis of AuNPs, B. hispida, peel, flesh and seeds were attempted. B. hispida seed alone had the ability to synthesise green AuNPs, and were characterised by its stability, physicochemical characterisation by HRTEM, EDX and FTIR for functional group analysis. The antioxidant activity, cytotoxicity and morphological changes in KB and vero cells were analysed. Results B. hispida seed extract alone synthesised AuNPs, which were spherical, particle size 60 to 80 nm with the elemental composition absorption peak at 0.2 and 2.2 keV. The functional groups O-H and C-O stretch shift was observed. The B. Hispida AuNPs at 100 ug/ml possessed maximum antioxidant activity of > 80%. The IC50 values were 73 µg/ml against KB cells and 84 µg/ml for vero cells and the viability of the cells were 94% and 26% respectively, thereby AuNPs reduced the oral cancer cell viability when compared to normal cells. The fluorescence staining AO/PI exhibited the colour change from green to orange and red confirmed early to late apoptosis and necrosis respectively. DAPI staining showed condensed nucleus with the reduction in green fluorescence due to the depletion of mitochondrial membrane during cell apoptosis. Conclusion These findings suggest that the seed of B. Hispida AuNPs could substantially improve the anticancer efficacy and hence may possess therapeutic potential when conjugated to antibodies targeting oral cancer.