Ultraviolet radiation and free radical damage to skin

1995 ◽  
Vol 61 ◽  
pp. 47-53 ◽  
Author(s):  
Rex M. Tyrrell

Solar UVB (290-320 nm) and particularly UVA (320-380 nm) radiations have a capacity to generate reactive chemical species, including free radicals, in cells. These intermediates have been shown to be involved in various biological effects in cultured human skin cells (e.g. cell death) and skin (e.g. erythema). Endogenous glutathione is a critical molecule in protection against the cytotoxic effects of both wavelength ranges. Although there is evidence from cellular studies for the involvement of an oxidative component of UVC/UVB radiations in activation of several genes, the doses used are generally extremely cytotoxic and could cause aberrant signalling. Genes activated by sublethal doses of UVA radiations (e.g. haem oxygenase 1 and the CL100 phosphatase) are clearly redox regulated. The strong induction of haem oxygenase 1 in human fibroblasts has been implicated in an adaptive response to oxidative membrane damage that involves increased synthesis of the iron storage protein, ferritin.

1999 ◽  
Vol 3 (2) ◽  
Author(s):  
AV Crowe ◽  
GM Bell

Oxygen-derived free radicals are highly reactive chemical species containing an unpaired electron. They are capable of reacting with lipids, proteins and nucleic acids and are thought to have a major role in the pathogenesis of a variety of diseases including atherosclerosis, diabetes and cancer. Antioxidants protect and limit free radical damage and it is the balance between free radical activity and antioxidant mechanisms that determine the potential for tissue damage [1,2]. Oxidative stress exists when there are either low levels of these antioxidants or increased production of reactive oxygen species (ROS).


2012 ◽  
Vol 1 (10) ◽  
pp. 79 ◽  
Author(s):  
G. Raja* ◽  
Ivvala Anand Shaker ◽  
Inampudi Sailaja ◽  
R. Swaminathan ◽  
S. Saleem Basha ◽  
...  

Natural antioxidants can protect the human body from free radicals and retard the progress of many chronic diseases as well as lipid oxidative rancidity in foods. The role of antioxidants has protected effect against free radical damage that may cause many diseases including cancer. Primary sources of naturally occurring antioxidants are known as whole grains, fruits, and vegetables. Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. The role of antioxidants has attracted much interest with respect to their protective effect against free radical damage that may cause many diseases including cancer. Juglans regia L. (walnut) contains antioxidant compounds, which are thought to contribute to their biological properties. Polyphenols, flavonoids and flavonols concentrations and antioxidant activity of Leaves, Stems and Nuts extract of Juglans regia L. as evaluated using DPPH, ABTS, Nitric acid, hydroxyl and superoxide radical scavenging activity, lipid peroxidation and total oxidation activity were determined. The antioxidant activities of Leaves, Stems and Nuts extract of Juglans regia L. were concentration dependent in different experimental models and it was observed that free radicals were scavenged by the test compounds in all the models.


2021 ◽  
Vol 11 (3) ◽  
pp. 1178
Author(s):  
Evanthia Tsoukou ◽  
Maxime Delit ◽  
Louise Treint ◽  
Paula Bourke ◽  
Daniela Boehm

The spread of multidrug-resistant bacteria poses a significant threat to human health. Plasma activated liquids (PAL) could be a promising alternative for microbial decontamination, where different PAL can possess diverse antimicrobial efficacies and cytotoxic profiles, depending on the range and concentration of their reactive chemical species. In this research, the biological activity of plasma activated water (PAW) on different biological targets including both microbiological and mammalian cells was investigated in vitro. The aim was to further an understanding of the specific role of distinct plasma reactive species, which is required to tailor plasma activated liquids for use in applications where high antimicrobial activity is required without adversely affecting the biology of eukaryotic cells. PAW was generated by glow and spark discharges, which provide selective generation of hydrogen peroxide, nitrite and nitrate in the liquid. The PAW made by either spark or glow discharges showed similar antimicrobial efficacy and stability of activity, despite the very different reactive oxygen species (ROS) and reactive nitrogen species profiles (RNS). However, different trends were observed for cytotoxic activities and effects on enzyme function, which were translated through the selective chemical species generation. These findings indicate very distinct mechanisms of action which may be exploited when tailoring plasma activated liquids to various applications. A remarkable stability to heat and pressure was noted for PAW generated with this set up, which broadens the application potential. These features also suggest that post plasma modifications and post generation stability can be harnessed as a further means of modulating the chemistry, activity and mode of delivery of plasma functionalised liquids. Overall, these results further understanding on how PAL generation may be tuned to provide candidate disinfectant agents for biomedical application or for bio-decontamination in diverse areas.


Author(s):  
D Özmen ◽  
I Mutaf ◽  
B Özmen ◽  
J Mentes ◽  
O Bayindir

This study aims to explore the role of reactive oxygen radicals in the genesis of diabetic cataract. Lipid peroxide (LPO) concentrations in senile ( n = 30) and diabetic ( n = 14) cataractous lenses, were determined as thiobarbituric acid-reactive substances (TBARS) by a method modified from Satoh and Yagi, and reduced glutathione (GSH) concentrations were measured according to Beutler. Lens LPO levels (mean, SD; nmol TBARS/g protein) were significantly higher in diabetics (107·54, 18·12) than senile cataractous subjects (53·54, 15·48) ( P < 0·0001). Lens GSH levels (mean, SD; nmol/g protein) showed no significant difference between diabetics (4·29, 2·05) and senile cataractous subjects (4·68, 3·12). These results suggest that free radical damage is more effective in the genesis of diabetic cataract than in senile cataract.


2009 ◽  
Vol 21 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Alexandra Rehfuss ◽  
Catherine Schuler ◽  
Christina Maxemous ◽  
Robert E. Leggett ◽  
Robert M. Levin

The Lancet ◽  
1990 ◽  
Vol 335 (8695) ◽  
pp. 933-936 ◽  
Author(s):  
H.M. Berger ◽  
J.H.N. Lindeman ◽  
D. van Zoeren-Grobben ◽  
E. Hudkamp ◽  
H.H. Kanhai ◽  
...  

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