Key Findings:
Erythema/edema and sunburn, inflammation, premature skin aging (photo aging) and melanogenesis can result from exposure to ultraviolet C, the most powerful and dangerous. UVC causes an increase of free radicals and initiates photo-oxidation which can damage the cellular components and inhibit DNA repair. Flax seed oil (FSO) administration was investigated. This study suffers from the lack of knowledge of the composition of FSO as the authors postulated that FSO might be a useful antioxidant nutrient because of its high lignan content. Lignans are not present in FSO and are a constituent of the seed hull fraction. However, in the current study, FSO showed a protective effect against UVC induced oxidative damage and retinal apoptosis. In this study, MDA and PC levels of the UVC group increased compared to the control group, their levels decreased in the UVC + FSO group compared with the UVC group in all tissues. In the presence of FSO, the decreased levels of MDA and PC suggested to the authors that FSO could scavenge oxygen radicals. FSO treatment might reduce UVC-induced apoptosis either by activation of the DNA repair systems or scavenging ROS. Regardless of the invalid hypothesis, FSO may help to prevent cells from the detrimental effects of UVC light or at least it reduces the injury.
ABSTRACT:
The aim of this study is to determine antioxidant and antiapoptotic effects of flax seed oil (FSO) on rats exposed to ultraviolet C (UVC). Malondialdehyde (MDA), protein carbonyl (PC) and reduced glutathione (GSH) levels as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured in lens, skin and serum. In addition, beta-carotene, vitamin A, C and E contents were measured in serum, while apoptosis was determined in retina. Rats were divided into three groups as control, UVC and UVC beta FSO. UVC and UVC + FSO groups were exposed to UVC light for 1 h twice a day for 4 weeks. FSO (4 ml/kg bw) was given by gavage before each irradiation period to the UV þ FSO group. While MDA and PC levels of the UVC group increased compared to the control group, their levels decreased in the UVC+FSO group compared with the UVC group in skin, lens and serum. Skin GSH level decreasedsignificantly in the UVC and UVC+ FSO groups. As GPx and SOD activities of the UVC group were lower, their activities were higher in the UVC + FSO group in skin, lens and serum. There was only marked elevation of vitamin A level in the UVC group compared to the control group. Apoptosis increased in the UVC group and the UVC + FSO groups in retina. However, retinal apoptosis were lower in the UVC + FSO group compared with the UVC group. This investigation demonstrated that UVC exposure led to oxidative stress and apoptosis in rats as reflected by increased MDA, PC contents and decreased enzymatic and nonenzymatic antioxidant levels, FSO may be useful for preventing photoreactive damage. (Author’s abstract)
Link to Full Text