Nanotechnology has opened new opportunities in the field of medical sciences and pharmaceuticals. Metal nanoparticles have tremendous applications in the field of high sensitivity biomolecular detection and diagnostics, antimicrobials and therapeutics, catalysis and micro-electronics. Green synthesis is the safe and easiest method of producing silver nanoparticles. The silver nanoparticles found to have the antibacterial activity because of the production of the silver ions. Cucurbita pepo (C. pepo) is a perennial creeping herb of Gourd family Cucurbitaceae. The seeds of which contain various phytoconstituents such as fixed oils, tocopherols, vitamins and minerals. In the present study the green nanoparticles were prepared by using ethanolic seed extract of  Cucurbita  pepo.  The synthesis of silver phyto nanoparticles were prepared by adding silver nitrate solution to the plant extract. Nanoparticles were characterised  using UV-Visible absorption and FTIR studies.  Antioxidant capacity of the Nanoparticles were tested on hydroxyl, DPPH and ABTS radicals by reducing power assay. Ascorbic acid was used as the standard antioxidant. HaCaT cell line  (Psoriatic skin cancer cell line)  were used as cell lines to assess its in vitro anticancer effect. The prepared Nanoparticles  showed considerable antioxidant and anticancer activities in dose dependant manner  in all the models tested. The minimum IC50 values of 48.87 ± 0.53 mcg/ml was shown in hydroxyl radical scavenging assay. At higher  doses of the nanoparticles (100μg/ml) showed significant cytotoxic effects on HaCaT cell line  (Psoriatic skin cancer cell line). These study results were concluded that silver nanoparticles of C. pepo exhibited excellent antioxidant activity against free radicals which were generated from different models and showed very good anticancer activity against HaCaT cell line , this results might be due to the phytoconstituent such as flavonoid  phytosterols  present in the plant extracts.  Further studies needed to find out the efficacy, longevity and toxicity to improve the current investigation. This is the first attempt of introducing silver phytonanoparticle, antimicrobial and cytotoxicity screening of  Cucurbita  pepo.

Keywords: Cucurbita pepo; nanoparticles; Antioxidant; Anticancer; HaCaT cell line