Analytical Methods for Enzyme and DPPH Radical Scavenging Activities of Natural Pigments from Some Plants

The enzyme activities in different fractions of Dioscorea japonica Thunb. and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity in 15 natural plant pigments from black rice, purple sweet potato, yellow bitter melon, yellow paprika, red cabbage, yellow gardenia, blue gardenia, Chinese foxglove, mulberry leave, onion peel, grape peel, mulberry, red beet, gromwell, and cactus were determined. The antioxidant activity in the cosmetic composition of mulberry leaves, grape peel, mulberry, and red cabbage pigments was relatively high in comparison with all other studied plants. Enzyme activities in investigated plants were evaluated as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The cosmetic composition of mulberry leaf pigment had the highest SOD enzyme activity of 67.1% while onion peel pigment showed the lowest SOD enzyme activity of 15.3%. The activity of CAT and APX from cosmetic composition of natural plant pigments has also been investigated. Both CAT and APX showed higher values in the cactus, mulberry, and red cabbage cosmetic compositions in comparison with other plant pigments. The cosmetic composition in EtOAc extract of D. japonica Thunb. had the highest SOD enzyme activity while the BuOH and EtOH extracts were comparatively low. CAT and APX activities showed significantly high values in EtOH and EtOAc extracts. The antioxidant enzyme activities of D. japonica Thunb. differ significantly in different plant pigments during their extraction. In conclusion, we showed that the plant pigments and D. japonica Thunb. had the potent biological activities. Therefore, these plant resources having anti-aging components could be good materials for development of source of natural cosmetics.