Melatonin and oxidative stress in melasma - an unexplored territory; a prospective study.

BACKGROUND: Melasma, an acquired disorder of hyperpigmentation, is the most common pigmentary disorder in India. Many factors are implicated in the pathogenesis, and recently the role of oxidative damage including melatonin has been postulated. This study was undertaken to evaluate the role of oxidative stress and serum melatonin in pathogenesis of melasma. METHODS: Seventy-five patients with melasma and an equal number of age and sex-matched controls were included in the study. Clinical characteristics were noted, and baseline severity assessment using modified Melasma Area and Severity Index (MASI) was done in all patients. Serum melatonin, catalase, protein carbonyl, and nitric oxide levels were measured and compared between cases and controls. RESULTS: The serum levels of melatonin and catalase were significantly lower among the cases as compared to controls, while the serum levels of protein carbonyl and nitric oxide were significantly higher in cases compared to controls. There was no statistically significant correlation between these markers of oxidative stress and severity of the disease. CONCLUSIONS: Oxidative stress is increased in patients with melasma compared to the control group in this study. A state of melatonin deficit also exists in patients with melasma. No correlation between the oxidative stress and severity of the disease was found. Further and larger studies including therapeutic trials with powerful antioxidants are warranted.

Role of oxidative stress in melasma: a prospective study on serum and blood markers of oxidative stress in melasma patients.

BACKGROUND: Melasma is a common pigmentary disorder presenting in the dermatological clinic. Many factors have been implicated in the pathogenesis, however, the cause still remains elusive. Recently the effect of oxidative damage has been proposed in the etiopathogenesis of melasma. This study was undertaken to evaluate the role of oxidative stress in patients with melasma. MATERIAL AND METHODS: Fifty patients with melasma, age 18 years of age and older, and an equal number of age and sex-matched controls were included in the study. Baseline severity assessment using the modified Melasma Area and Severity Index (modified MASI score) was done in all patients. Serum malondialdehyde, blood superoxide dismutase, and blood glutathione peroxidase levels were measured in cases and controls group and results were compared. RESULT: The serum levels of malondialdehyde, superoxide dismutase, and blood glutathione were significantly higher among the cases compared to controls. The difference in the serum concentrations was significant between the two groups (P < 0.01). A positive correlation was found between these enzyme levels and severity of melasma (modified MASI score); however, this correlation was statistically significant with serum malondialdehyde only. The level of oxidative stress among the male and female melasma patients was not statistically different. CONCLUSION: Oxidative stress was found to be increased in cases of melasma compared to the control group in this study. This substantiates the role of oxidative stress in etiopathogenesis of melasma; however, further studies are required to reach a definitive conclusion.