Chemopreventive Potential of Sunflower Seeds in a Human Colon Cancer Cell Line

Abstract

Sunflower Seed (SS) (Helianthus annuus L.) is an oil seed crop that is a good source of protein. The objective of this study was to investigate the chemopreventive potential of SS extracts (defatted and whole) through determination of phytochemical content, antioxidative potential and cytotoxic effects on Caco-2 cells. Phytochemical (total phenolic, total flavonoid) content, Trolox Equivalent Antioxidant Capacity (TEAC), free radical-scavenging ability of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Potential (FRAP) were determined according to standard protocol. Lactate dehydrogenase (LDH) release (cytotoxicity assay) was used to measure in vitro cell damage of Caco-2 colon cancer cells. Activity of cellular detoxification and antioxidant enzymes was determined with selected concentrations of SS extracts (25, 50 and 100 μg mLG). Apoptotic activity was assessed through the activity of Caspase-3 and DNA fragmentation ELISA. Anti-inflammatory activity was assessed through Cox-2. Total phenolic content was 62.76±7.37 mg GAE/100 g and total flavonoid content of SS extracts was 26.49 mg CE/100 g. Antioxidant potential: TEAC was 858.83±97.7 μmol TE/100 g, DPPH radical scavenging (IC50 value) was 8 mg mLG 1 and FRAP was 14.13±1.25 mmol/Fe/g for SS extracts. The LDH release (%), cytotoxicity, after 12 and 24 h incubation with SS extracts was 39.8 and 53.1% at 25 μg mLG. Caspase-3 activity was 18.60±0.19, Cox-2 was 0.28 U mLG and DNA fragmentation ELISA was 0.47 EF at 24 h incubation of extract at 100 μg mLG. The results for the antioxidant and detoxification enzymes yielded were: GST (0.0017±0.001 nmol minG mLG), CAT 24.1±0.13 U mgG, GPx 30.4±0 nmol minG mLG, SOD 313.3±3.98 U mLG and GSH 13.7± nmol mLG. Results of this study revealed high phenolic and flavonoid content and suggested cytotoxic and antioxidative potential of SS extracts as a chemopreventive agent.