Antioxidant Activity of Silver Nanoparticles Prepared from Capsicum Annuum (Bell Pepper) Extract

Abstract

Vegetables have reported to contain high content of wide verity of important phytochemicals that can be used in medical approach. Bell pepper are one of the most important vegetables that can be used as spice in foods, as well as it has a diversity of the phytochemical compounds. Carotenoids, vitamin A, vitamin C, polyphenolic compounds and other metabolites were found in bell peppers of all colors. Red pepper is characterized by its high content of β-carotene. Our goal was to prepare an aqueous red pepper extract solution and use it to synthesize Ag NPs, then examine the antioxidant activity of the extract and the nanoparticle solutions. Ag NPs were prepared at room temperature by utilizing the aqueous red pepper extract solution as well as characterized by using UV-Vis spectrophotometry and field emission scanning electron microscope. The characterization result has shown the presence of Ag NPs in particle average of approximately 58 nm. The antioxidant activity was determined by using a DPPH assay, where ascorbic acid has shown IC50 of 23.71 μg/mL which was lower than Ag NPs (IC50 = 43.72 μg/mL). The best antioxidant behavior was obtained from the red pepper extract solution (IC50 = 17.26 μg/mL). This may attributed to the high content of phytochemicals in the extract solution. Importantly, the use of red pepper extract solution in preparing AgNPs have shown to improve their antioxidant activity, which is considered as good additive to the medical features of Ag NPs.