The pathogenetic mechanisms in vitiligo have not been completely clarified. One of the major hypotheses in the pathogenesis of vitiligo is the oxidative stress hypothesis. The active or stable phase of vitiligo is defined on the basis of the progression or appearance of new lesions in the last 3 months and the absence of new lesions or their progression in the last 6 months, respectively. Eighteen patients with active vitiligo, 18 patients with stable vitiligo, and 40 controls were included in this study. We examined serum levels of malondialdehyde, selenium, vitamin E and A, and the erythrocyte activities of glutathione peroxidase, superoxide dismutase, and catalase. Our results revealed a significantly higher level of serum malondialdehyde, selenium in patients with active disease compared with the controls. Significant higher increase in erythrocytes superoxide dismutase activities was observed in active vitiligo group, erythrocyte glutathione peroxidase activity was decreased significantly in active disease, whereas erythrocyte catalase activity and plasma vitamin E and A levels were not different in vitiligo patients as compared with controls. Our study shows that oxidative stress is involved in the pathophysiology of both active and stable vitiligo but increased imbalance of antioxidants was observed in the blood of active vitiligo patients.

Our study shows that oxidative stress is involved in the pathophysiology of both active and stable vitiligo, but an increased imbalance of antioxidants is observed in the tissues of patients with active vitiligo.

The aim of this study was to investigate the oxidative stress status and antioxidant enzyme activities in infertile men's semen and to determine their relationship with spermatozoa characteristics. Four groups of infertile men, normozoospermic (n=9), azoospermic (n=13), oligoasthenozoospermic (n=38), and asthenozoospermic (n=42), were tested for malonaldialdehyde (MDA) concentration and catalase (CAT) and superoxide dismutase (SOD) activities in semen using spectrophotometric methods. We found that MDA levels in semen and SOD activity in seminal plasma (SP) were significantly higher in oligoasthenozoospermic and asthenozoospermic groups compared with normozoospermic group. In contrast, the mean values of CAT activity were not significantly different in all groups. We found positive correlations between semen MDA concentration and SOD activity (P<0.01). MDA levels in sperm pellet and in SP were also positively correlated with mobility grade b (P<0.01), acrosome anomalies (P<0.01), and residual cytoplasmic droplets (P<0.05). In contrast, SOD activity in SP was negatively correlated with sperm concentration and normal morphology (P<0.05). Similarly, CAT activity in SP was negatively correlated with sperm and leukocyte concentrations (P<0.05). In conclusion, our results suggest that the evaluation of oxidative status and antioxidant defenses may be taken as an important tool for diagnosis and treatment of male infertility.

The pathobiology of vitiligo has been hotly disputed for as long as one remembers, and has been a magnet for endless speculation. Evidently, the different schools of thought--ranging, e.g. from the concept that vitiligo essentially is a free-radical disorder to that of vitiligo being a primary autoimmune disease--imply very different consequences for the best therapeutic strategies that one should adopt. As a more effective therapy for this common, often disfiguring pigmentary disorder is direly needed, we must strive harder to settle the pathogenesis debate definitively--on the basis of sound experimental evidence, rather than by a war of dogmatic theories. Recognizing, however, that it is theories which tend to guide our experimental designs and choice of study parameters, the various pathogenesis theories on the market deserve to be critically, yet unemotionally re-evaluated. This Controversies feature invites you to do so, and to ask yourself: is there something important or worthwhile exploring in other pathogenesis scenarios than those already favoured by you that may help you improve your own study design, next time you have a fresh look at vitiligo? Vitiligo provides a superb model for the study of many fundamental problems in skin biology and pathology. Therefore, even if it later turns out that, as far as your own vitiligo pathogenesis concept is concerned, you have barked-up the wrong tree most of the time, chances are that you shall anyway have generated priceless new insights into skin function along the way.

A critical step to escape from the carcinogenic potential of UV radiation is mediated by the protein p53. P53 activates growth arrest, allowing for DNA repair, which removes damaged cells. The concept of photoprotection involves blocking apoptosis and the prevention of oxidative damage to cellular DNA. Date seed oil (DSO) extract has been reported to be beneficial in the reduction of chemically induced oxidative stress in normal human skin. In this study, we investigated the DNA-protective qualities of DSO as measured by p53 expression in human skin biopsies, one day after exposure to ultraviolet B (UVB) radiation. P53 expression was analyzed using immunohistochemistry. The results showed an increase in p53 expression in the basal cell compartment of UVB-exposed skin as compared to the non-UVB-exposed skin. However, DSO has significant photoprotective effects by inhibition of damage caused by UVB irradiation: a significantly lower fraction of cells was p53 positive as compared to the non-DSO-treated skin. We conclude that p53 expression is a sensitive parameter for the detection of UVB-induced damage in the skin and suggest that DSO could provide an efficient complement to photoprotective measures and may contribute to reduce the DNA damage.