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.