Variation of antioxidant activity and polyphenol content in safflower (Carthamus tinctorious) germplasm collection

Safflower originated from Egypt and Afghanistan is an annual herb which usually used as the medicinal crop in Asian countries. Safflower seeds, rich in unsaturated fatty acid and α-linoleic, have been used for the promotion of bone formation, clinical treatment of osteoporosis and rheumatism in Korea. In order to identify the genetic resources with high antioxidant activity, we investigated the ABTS, DPPH and polyphenol content in safflower germplasm. A total of 100 safflower accessions which had collected from two sites adjacent to the northern area of the Saudi Arabian peninsula were obtained from National Biodiversity Center of South Korea. Safflower seed extracts showed wide variation in ABTS antioxidant activity ranging from 34.5 ± 0.70 to 156.5 ± 3.06 µg trolox mg^-1 dw. The antioxidant activity of DPPH was in the range of 1.6 ± 0.070 to 14.1 ± 0.23 µg ABC mg^-1 dw. Total polyphenol content ranged from 14.2 ± 0.41 to 81.6 ± 1.56 µg GAE mg^-1 dw. ABTS, DPPH antioxidant activity and polyphenol content were not different according to the collection sites. However, ABTS values showed a significant positive correlation (r = 0.95) with DPPH antioxidant activity. Among the accession, K185841, K185863 and K185879 which showed high content of total polyphenol and antioxidant activity were recommended as a potential sources of safflower breeding. This study will provide the valuable information for safflower breeder in developing and producing functional materials.