Biological activities of sweet potato (Ipomoea batatas L.) tips and tubers.

This study was conducted to evaluate the biological activities of sweet potato tips and tubers. Antioxidant activity of 2,2-azino-bis 93-ethlbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities had the highest value of 32.45 mg, AAE/g, and 15.10 mg AAE/g, respectively, in 'Pungwonmi' tips. Angiotensin converting enzyme I inhibitory activity ranged between 47.72% in 'Sinjami' tubers and 62.25% in 'Pungwonmi' tips. α-Glucosidase inhibitory activity had the highest value of 78.81% and 62.93% in 'Pungwonmi' tips and 'Juhwangmi' tubers, respectively. In particular, 'Pungwonmi' tips had the most effective inhibiting effect on intracellular reactive oxygen species levels in HepG2 cells. Wound healing assay result revealed that 'Sinjami' showed 75% wound healing effect. For skin whitening, 'Pungwonmi' tips showed 63% activity at 10 mg/ml. These results suggest that sweet potato tips and tubers can be used to develop functional food and cosmetic materials.