Epidermal hydrogen peroxide is not increased in lesional and non-lesional skin of vitiligo.

It is widely believed that the loss of the epidermal melanocytes in vitiligo is basically due to excessive oxidative stress. Previous research work described abnormal elevation of the absolute concentration of the epidermal hydrogen peroxide (H2O2) in lesional and non-lesional skin of vitiligo. Based on this finding, our primary research objective was to use this feature as a screening marker in individuals at a great risk of developing vitiligo. Ninety-six patients of non-segmental vitiligo (NSV) of varying durations, skin phototypes, and treatment modalities (psoralen UVA-, narrow band UVB-treated) were recruited for this study. Raman spectroscopic measurements, using an external probehead, of the lesional and non-lesional skin were obtained, and the resulting spectra were analyzed using the Opus software package of the MultiRam spectrometer and the intensity of the peak at 875 cm-1 that represents the absolute concentration of H2O2 was calculated. Contrary to previous reports, in patients of skin phototype IV, the absolute concentrations of H2O2 in non-lesional and lesional NSV of all groups were non-significantly decreased compared to normal control. In patients of NSV of skin phototype V, the decrease in the absolute concentrations of H2O2 was not significant in the untreated group, and a slight non-significant increase in the NBUVB-treated group was noted. However, in the PUVA-treated group, the non-lesional skin demonstrated significant increase in the absolute concentration of H2O2, whereas the lesional skin showed only a slight non-significant increase compared to normal control. In NSV patients of skin phototype VI who were previously treated with PUVA, the non-lesional skin showed a slight non-significant increase in the absolute concentration of H2O2; however, the lesional skin showed a marked significant decrease compared to normal control and the non-lesional skin. Thereof, one can conclude that the epidermal H2O2 is not increased in NSV as previously thought and may not be responsible for the oxidative stress that leads to the melanocytes destruction, the hallmark of vitiligo pathogenesis.

Aspirin reduces serum anti-melanocyte antibodies and soluble interleukin-2 receptors in vitiligo patients.

OBJECTIVE: Increased serum levels of certain immunologic markers including immunoglobulin G (IgG) anti-melanocyte/ vitiligo antibodies (V-IgG) and soluble interleukin-2 receptors (sIL-2R) are associated with augmented humoral and cellular immunity involved in melanocyte cytotoxicity during the active phase of non-segmental vitiligo. Recent reports have shown that, aspirin possesses a wide range of immunomodulatory and antioxidant properties. Therefore, the aim of the present study is to investigate the effect of long-term treatment of vitiligo patients with low-dose oral aspirin on serum V-IgG activity and sIL-2R concentration. METHODS: The present study was carried out at the Vitiligo Unit, King Abdul-Aziz University Medical Center, Jeddah, Kingdom of Saudi Arabia between March and October 2003. Eighteen female and 14 male patients with a recent onset of non-segmental vitiligo were divided into 2 equal groups. One group received a daily single dose of oral aspirin (300 mg) and the second group received only placebo for a period of 12 weeks. Serum V-IgG activity and sIL-2R concentration were determined before and at the end of treatment period. The V-IgG activity was measured using cellular enzyme-linked immunosorbent assay (ELISA) following incubation of IgG antibodies with an adult cultured melanocytes. Serum sIL-2R concentration was measured using the highly sensitive quantitative sandwich ELISA utilizing a commercially available kit. RESULTS: As expected, the serum V-IgG activity and sIL-2R concentration of the active vitiligo patients (0.81 +/- 0.23 optical density (O.D.), 1428 +/- 510 pg/ml) were significantly increased compared with that of controls (0.27 +/- 0.1 O.D., 846 +/- 312 pg/ml; p<0.05, p<0.01). Aspirin-treated vitiligo patients showed significant decrease in serum V-IgG activity and sIL-2R concentration (0.32 +/- 0.08 O.D., 756 +/- 216 pg/ml) compared with that of placebo-treated patients (0.83 +/- 0.19 O.D., 1327 +/- 392 pg/ml; p<0.01). CONCLUSION: Low-dose oral aspirin treatment of active vitiligo patients can cause significant reduction in the acute serum immunologic markers of T cell activation, V-IgG activity and sIL-2R concentration with concomitant arrest of disease activity.

Decreased proinflammatory cytokine production by peripheral blood mononuclear cells from vitiligo patients following aspirin treatment.

OBJECTIVE: Limited studies have shown that treatment of cells with aspirin modulates their cytokine production. Consequently, the aim of the present study is to investigate the pattern of important proinflammatory cytokines production by stimulated peripheral blood mononuclear cells (PBMC) from patients with active vitiligo following long-term treatment with low-dose oral aspirin. METHODS: The study was conducted at the Vitiligo Unit, King Abdul-Aziz University Medical Center, Jeddah, Kingdom of Saudi Arabia between March and October 2003. Thirty-two patients (18 females and 14 males) with non-segmental vitiligo were divided into 2 equal groups, one group received a daily single dose of oral aspirin (300 mg) and the other group received placebo for a period of 12 weeks. The concentrations of interleukin (IL)-1beta, IL-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) were determined in the supernatant of isolated cultured PMBC after being stimulated with bacterial lipopolysaccharide (LPS), before the start of aspirin treatment and at end of treatment period. Cytokine levels were measured using the quantitative sandwich enzyme-linked immunosorbent assay (ELISA) technique, utilizing commercially available kits. RESULTS: The proinflammatory cytokine production by the PBMC of patients with active vitiligo was significantly increased compared to normal controls. Thus, the relative percentage increase in the production of IL-1beta, IL-6, IL-8 and TNF-alpha was: 39.4%, 110.5% (p<0.05), 91.5% (p<0.01), and 37% (p<0.05). At the end of treatment, proinflammatory cytokine production in the aspirin-treated group of active vitiligo patients was significantly decreased compared to the placebo group. Thus, the relative percentage decrease in the production of IL-1beta IL-6, IL-8 and TNF-alpha was: 42.5%, 45.2% (p<0.05), 30.8% (p<0.01), and 50.6% (p<0.05). The vitiligo activity was arrested in all aspirin-treated patients, while 2 patients demonstrated significant repigmentation. CONCLUSION: Chronic administration of low-dose oral aspirin can down-regulate the PBMC proinflammatory cytokine production in active vitiligo with concomitant arrest of disease activity.

Short- and long-term effects of acetylsalicylic acid treatment on the proliferation and lipid peroxidation of skin cultured melanocytes of active vitiligo.

OBJECTIVE: Recent in vitro and in vivo studies have shown that the nonsteroidal anti-inflammatory agent, acetylsalicylic acid (ASA) or aspirin has antioxidant properties on various cell lines and tissues. Hence, the aim of the present study is to investigate the effects of ASA at 2 different concentrations (75 and 300 microg/ml) on the proliferative capacities and lipid peroxidation of in vitro skin cultured melanocytes obtained from patients with active vitiligo. METHODS: The present work was carried out from February 2001 through to November 2001, at the Vitiligo Unit, King Abdul-Aziz University Medical Center, Jeddah, Kingdom of Saudi Arabia. Employing methods described in this section, cryopreserved primary cultured melanocytes that were originally cultured from skin biopsies of normal healthy individuals and patients with active vitiligo (n=7), were subcultured to confluence. The malondialdehyde (MDA) concentrations in the cell culture medium were determined at 6 hours and 21 days following cultured melanocytes treatment with ASA (75 and 300 microg/ml). Also, the number of viable melanocytes was determined 21 days following the treatment of melanocytes with ASA (75 and 300 microg/ml). RESULTS: Following ASA treatment at 75 microg/ml, the cultured melanocytes from the normal and active vitiligo donors showed significant increase in the proliferative capacities as judged by the increase in the number of viable melanocytes after 21 days of cell culture (28.2% and 26.9%, p<0.001). Concomitantly, the same ASA concentration resulted in significant decrease in the concentrations of MDA in the cell culture medium of the normal and active vitiligo melanocytes 6 hour and 21-day period following the ASA treatment [6 hour: 16.2% (p<0.05) and 18.4% (p<0.001); 21 day: 32% and 38.6% (p<0.001)]. However, the long-term (21 days) treatment of cultured melanocytes from the normal and active vitiligo donors with ASA at 300 microg/ml resulted in a significant reduction in the number of viable melanocytes (33.6% and 63.5%, p<0.001). Whereas, MDA concentrations 6 hour and 21-day period following the ASA treatment had significantly increased [6 hour: 28.6% (p<0.05) and 41.3% (p<0.001) 21 day: 92.8% and 127.8% (p<0.001)]. CONCLUSION: Low-dose ASA (75 microg/ml) may confer protection of skin melanocytes from the normal and active vitiligo donors against lipid peroxidation and up-regulate their proliferative capacities. On the other hand, high-dose ASA (300 microg/ml) may have deleterious effects on the melanocytes, increasing lipid peroxidation and hence may potentiate melanocyte apoptosis.

The effect of acetylsalicylic acid on the release rates of leukotrienes B4 and C4 from cultured skin melanocytes of active vitiligo.

OBJECTIVE: The aim of this study is to investigate the effect of the non-steroidal anti-inflammatory agent, acetylsalicylic acid (ASA), otherwise known as aspirin, at different concentrations on the release rates of the pro-inflammatory mediators, leukotriene B4 (LTB4) and leukotriene C4 (LTC4) from in vitro cultured melanocytes obtained from normal pigmented skin of patients with active vitiligo. METHODS: This study was carried out between April, 2000 and September, 2001, at The Vitiligo Unit, King Abdul-Aziz University Medical Center, Jeddah, Kingdom of Saudi Arabia. Skin biopsies were obtained from patients with active vitiligo (n=7) of different extent and duration, and normal healthy age-matched individuals (n=7) serving as control were recruited to the study. The release rates of LTB4 and LTC4 were determined before and after the addition of the ASA at 3 different concentrations (15, 75, 150 microg/ml) in the primary skin melanocytes culture medium using a commercially available kit based on radioimmunoassay method. RESULTS: Following the ASA treatment at 3 different concentrations (15, 75 and 150 microg/ml), the release rates of LTB4 and LTC4 were increased from melanocytes of the normal individuals (13%, 7.5% and 30%; 7.2%, 51.4% and 60.7%, p<0.001). However, in patients with active vitiligo, the release rate of LTB4 from melanocytes was decreased (2.9%, 14.4% and 7.4%, p<0.05), whereas that of LTC4 was increased (3.9%, 93.8% and 101.4%, p<0.001). CONCLUSION: Acetylsalicylic acid at therapeutic concentrations can regulate the release rates of LTB4 and LTC4 from cultured skin melanocytes of normal and active vitiligo subjects.

Alterations of erythrocyte free radical defense system, heart tissue lipid peroxidation, and lipid concentration in streptozotocin-induced diabetic rats under coenzyme Q10 supplementation.

OBJECTIVE: Free radicals play an important role in genesis and development of various chronic diseases and aging. Our objective is to study the effects of coenzyme Q10 (CoQ10) supplementation on erythrocyte antioxidants, heart tissue lipid peroxidation end products and lipid concentration in different age of diabetic rats. METHODS: In this study, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the content of reduced glutathione (GSH) were determined in erythrocytes. The products of lipid peroxidation were determined in the heart tissues of streptozotocin-induced diabetic rats and in healthy rats at 4, 8, and 13-months of age. The above mentioned antioxidant systems of erythrocytes were also determined after supplementation of diabetic and healthy rats with CoQ10. This study was carried out in King Fahad Medical Research Center, Jeddah, Kingdom of Saudi Arabia between 2000 and 2001. RESULTS: In erythrocytes of diabetic rats the activity of GSH-Px was significantly decreased (p<0.001) in all different age groups, whereas the activity of SOD was significantly increased (p<0.001). However, in erythrocyte of streptozotocin-induced diabetic rats, the concentration of GSH and high-density lipoprotein (HDL)-cholesterol were significantly lower than non-diabetic rats. Moreover, the concentration of heart tissue lipid peroxidation end products, and plasma glucose, cholesterol and triacylglycerol were significantly increased (p<0.001) in all age groups of diabetic rats. Daily supplementation with CoQ10 (10 mg/kg body weight, one month) after induction of diabetes to the rats resulted in the following changes: an increase in both erythrocyte GSH concentration and GSH-Px activity, and slightly increases in plasma HDL-cholesterol. However, SOD activity was significantly decreased (p<0.05). In addition, the levels of lipid peroxidation end products, and triacylglycerol were significantly decreased (p<0.05) in diabetic rats supplemented with CoQ10. CONCLUSION: The results of the present study indicated that CoQ10 supplementation helps to prevent clinical complications during the course of the disease in diabetic rats.