Photoprotective effect of flax seed oil (Linum usitatissimum L.) against ultraviolet C-induced apoptosis and oxidative stress in rats.
Photoprotective effect of flax seed oil (Linum usitatissimum L.) against ultraviolet C-induced apoptosis and oxidative stress in rats.
Year: 2011
Authors: Tuluce, Y. Ozkol, H. Koyuncu, I.
Publication Name: Toxicol. Ind. Health
Publication Details: Jun 10; Pages 1 – 9.
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 ? 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 decreased significantly 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)
Ultraviolet (UV) leads to different health problems, including erythema/edema and subsequent pigmentation (sunburn), inflammation, premature skin aging (photoaging) and melanogenesis. The UV spectrum range consists of ultraviolet A (UVA; 320 to 400 nm), ultraviolet B (UVB; 280 to 320 nm) and ultraviolet C (UVC; 200 to 280 nm). Among these, the most powerful and dangerous one is UVC. UV causes an increase of free radicals and initiates photo-oxidation which can damage the cellular components and inhibit DNA repair. In recent years, natural compounds which possess antioxidant and anti-inflammatory properties have created considerable interest as protective agents for reducing radiation-induced skin damage. In this study, the protective effect of oral flax seed oil (FSO) administration were 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. In the current study, the activity of antioxidant enzymes including glutathione peroxidase (GPx) and superoxide dismutase (SOD) and the alterations in the levels of reduced glutathione (GSH), malondialdehyde (MDA) and protein carbonyl (PC) in rat serum, skin and lens as well as serum antioxidant vitamin levels with retinal apoptosis were investigated to determine whether FSO alters UVC effect by scavenging free radicals. Even though tested under an invalid hypothesis, 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. Apoptosis which is an active process of cell destruction characterized by cell shrinkage, cytoplasmic blebbing, cell rounding, chromatin condensation with extensive nuclear fragmentation and nuclear pyknosis, was also tested. Antioxidants may prevent apoptosis by depletion of ROS. In this study, retinal apoptosis increased in the UVC group compared to the control and the UVC + FSO groups. However, it was lower in the UVC + FSO group compared with the UVC group. FSO treatment might reduce UVC-induced apoptosis either by activation of the DNA repair systems or scavenging ROS. the authors concluded that the current study demonstrates that UVC light damages the antioxidant defense system and induces apoptosis in different tissues of rats. In addition, oral consumption of FSO is of benefit by preventing cells from the detrimental effects of UVC light or at least it reduces the injury. (Editor's comments)
Ultraviolet (UV) leads to different health problems, including erythema/edema and subsequent pigmentation (sunburn), inflammation, premature skin aging (photoaging) and melanogenesis. The UV spectrum range consists of ultraviolet A (UVA; 320 to 400 nm), ultraviolet B (UVB; 280 to 320 nm) and ultraviolet C (UVC; 200 to 280 nm). Among these, the most powerful and dangerous one is UVC. UV causes an increase of free radicals and initiates photo-oxidation which can damage the cellular components and inhibit DNA repair. In recent years, natural compounds which possess antioxidant and anti-inflammatory properties have created considerable interest as protective agents for reducing radiation-induced skin damage. In this study, the protective effect of oral flax seed oil (FSO) administration were 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. In the current study, the activity of antioxidant enzymes including glutathione peroxidase (GPx) and superoxide dismutase (SOD) and the alterations in the levels of reduced glutathione (GSH), malondialdehyde (MDA) and protein carbonyl (PC) in rat serum, skin and lens as well as serum antioxidant vitamin levels with retinal apoptosis were investigated to determine whether FSO alters UVC effect by scavenging free radicals. Even though tested under an invalid hypothesis, 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. Apoptosis which is an active process of cell destruction characterized by cell shrinkage, cytoplasmic blebbing, cell rounding, chromatin condensation with extensive nuclear fragmentation and nuclear pyknosis, was also tested. Antioxidants may prevent apoptosis by depletion of ROS. In this study, retinal apoptosis increased in the UVC group compared to the control and the UVC + FSO groups. However, it was lower in the UVC + FSO group compared with the UVC group. FSO treatment might reduce UVC-induced apoptosis either by activation of the DNA repair systems or scavenging ROS. the authors concluded that the current study demonstrates that UVC light damages the antioxidant defense system and induces apoptosis in different tissues of rats. In addition, oral consumption of FSO is of benefit by preventing cells from the detrimental effects of UVC light or at least it reduces the injury. (Editor's comments)
