Effects of extracts from Sargassum spp. on attenuating ultraviolet Binduced cell damage
學生姓名:
劉芳伶
指導教授:
黃崇雄
學期:
111上
摘 要:
Frequent exposure to UV radiation results in photo-aging of the skin. Many skin diseases, such as cancer, photoaging, sunburn, and pigmentation are closely associated with UVB exposure. Moreover, UVB will penetrate the basal cell layer of epidermal cells to reach the dermis, and induce abnormal generation of reactive oxygen species (ROS), leading to oxidative stress, mitochondria mediated apoptosis and cell DNA damage, and affecting the physiological functions of keratinocytes and fibroblasts. Therefore, the aim of these studies is to investigate the effect of extracts from Sargassum spp. on the attenuating UVB-induced cell damage. In the first study, the total polyphenol content of Sargassum thunbergii phenolic-rich extract (STPE) was 72%. STPE reduced ROS content in L929 cells, improved superoxide dismutase (SOD) and catalase (CAT) activities, and significantly reduced malondialdehyde (MDA) content, thereby effectively alleviating UVB radiation-induced oxidative damage. Moreover, STPE inhibited NF-κB signaling pathway activation and alleviated DNA agglutination in L929 cells after UVB irradiation. In the second study, methanol extract from Sargassum horneri (SHM) significantly improved cell viability of UVB-exposed human keratinocytes by reducing the generation of intracellular ROS. Moreover, SHM inhibited UVB-induced apoptosis by reducing the formation of apoptotic bodies and the populations of the sub-G1 hypodiploid cells and the early apoptotic cells by modulating the expression of the anti- and pro-apoptotic molecules, Bcl-2 and Bax, respectively. Furthermore, SHM inhibited NF-κB p65 activation by inducing the activation of Nrf2/HO-1 signaling. The cytoprotective and antiapoptotic activities of SHM were abolished by the inhibition of HO-1 signaling. Based to these results, SHM protects the cells against UVB-induced cellular damages through the Nrf2/HO-1/NFκB p65 signaling pathway and may be potentially useful for the prevention of UVBinduced skin damage.
碩一上-seminar-摘要.pdf