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.