| Summary: | 碩士 === 中山醫學大學 === 應用化學系碩士班 === 104 === Introduction:
UV radiation can cause damages in the form of sunburns, primarily from wavelengths of 100~280nm, with shorter wavelengths being more harmful. In many previous studies, UV light (including type A, B, and C) creates reactive oxygen species in skin cells, which lead to inflammation, discoloration and tumorigenesis. ROS affect MAPK and NF-kB signal pathways which lead to pathological changes. Therefore, reducing the amount of ROS can reduce the damage caused by UV light.
Objectives:
Ocimum gratissimum contains plant polyphenones such as isoflavones and caffeic acid, which have antioxidant effects. We hypothesize that Ocimum gratissimum can inhibit the oxidative damage on skin cells. In this study, HaCaT skin cells are used to test the protective effects of Ocimum gratissimum on cell proliferation and growth after exposure to UV radiation.
Methods and Results:
After treated with different dose (0，40，60及80 J/m2) of UVC in HaCaT cells, the results showed that the survival rate was 100%,32.25%,18.49%, and 11.49% respectively. When we pre-treated with different dose (0,50,75,100,125,150μg/mL) of 007 extracts, the decrease of survival rate by the 40 J/m2 UVC was restored at 32.25%, 46.77%,57.90%,56.85%, 54.84, and 68.00% respectively, by 60 J/m2 at 18.49%, 28.50%, 41.25%, 41.21%, 48.21%, and 56.47% respectively, and by 80 J/m2 at 11.49%, 19.07%, 29.60%, 40.00%, 40.14%, and 43.04% respectively. The flow cytometry analysis revealed that UVC increased the number of cells arrested at the S phase in a UVC dose dependent manner. When we pre-treated with 007 extracts, the changes were reversed. Moreover, the wound healing also showed that the 007 extracts can restore the inhibition of cell migration by UVC.
From flow cytometry analysis, we found that with increasing UV energy density, adding OGE shows a recovery of cell counts in S phase and G0/G1 phase, whereas the absence of OGE will reduce the cell counts in these phases. This suggests that OGE may have protected the cells against apoptosis after exposure to UV light.
Wound healing was also tested in this study, and the results show that regardless of exposure to UV light, OGE accelerated wound healing.
Conclusion:
Based on the above results, we conclude that at higher amount of UV exposure, OGE has a protective effect on skin cells. We will further confirm our hypothesis using western blot to probe possible mechanisms of OGE.
|
|---|
