Sea buckthorn (Hippophae rhamnoides L.) is a well-known and rich source of biologically active compounds, such as flavonoids, carotenoids, steroids, vitamins, tannins, and oleic acid. The effects of sea buckthorn fruit extract (SBFE) on ultraviolet (UV)-induced cell death was investigated in SK-MEL-2 cells cotreated with UV and a low concentration (LoC), medium concentration (MeC), or high concentration (HiC) of SBFE. Cell viability gradually decreased in accordance with an increase in the UV dose. The cell viability of the UV+SBFE cotreated cells increased significantly compared to that of UV+vehicle-treated cells during the application of an appropriate UV radiation dose (400 mJ). In addition, the number of 4',6-diamidino-2-phenylindole (DAPI), propidium iodine (PI)-, and annexin V-stained apoptotic cells was higher in the UV+vehicle-treated cells than in the UV untreated cells. The decrease of apoptotic cell numbers varied in each treated group, but it was most significant in the SBFE-treated group. The number of PI-stained cells dramatically decreased in accordance with the concentration of SBFE, and the maximum decrease was detected in the UV+HiC-treated group. In addition, Bax expression increased and Bcl-2 expression decreased in the SBFE-treated group compared with the UV-only treated group. The level of caspase-3 remained constant in all the groups. These results suggest that SBFE may contribute to a recovery from UV-induced cell death through the regulation of apoptotic protein expression and that it may have potential therapeutic utility in ameliorating UV-induced skin ageing. 한편, UV조사로 세포 내에 유도된 산화적 스트레스는 세포 반응을 개시하고 일련의 반응을 유도하는 과정에서 매우 중요 한 역할을 한다 [25,30]. 특히, 세포 내 ROS를 생성시켜 미토콘 드리아를 비롯한 세포의 기능을 손상시킨다 [6]. UV조사에 의 한 미토콘드리아의 기능 손상은 cytochrome c의 분비에 의한 caspase-3의 활성화로 인해 apoptosis를 유발시킨다. Apoptosis 는 Bax와 Bcl-2의 경쟁에 의해 조절되며 Bcl-2는 Bax를 조절하