Melatonin metabolite 6-Sulfatoxymelatonin, Cu/Zn superoxide dismutase, oxidized LDL and malondialdehyde in unstable angina.

BACKGROUND

Melatonin, a lypophylic antioxidant, was reported to be low in patients suffering from myocardial infarction, a disease due to coronary atherosclerosis associated with increased reactive oxygen species. Studies carried out till now have shown association of either melatonin or another antioxidant Cu/Zn SOD in patients suffering from coronary artery disease but not both together. Concurrent measurement of these two parameters will reveal the relationship if any in the probable causation of the disease.

METHODS

We estimated the serum malondialdeheyde, oxidized LDL, lipid profile and activity of Cu/Zn superoxide dismutase and the concentration of urinary metabolite of melatonin, 6-Sulfatoxymelatonin in 24 h urine sample collected from 21 patients suffering from unstable angina and 30 control subjects.

RESULTS

A statistically significant decrease in urinary melatonin levels (p <0.05), serum Cu/Zn SOD (p <0.001) along with significant increase in serum oxidized LDL (p <0.001), serum malondialdeheyde (p <0.01) were observed in patients compared to controls.

CONCLUSION

Our observations indicate that a decreased excretion of 6-Sulfatoxymelatonin may be causally related to a decrease in serum Cu/Zn SOD, an antioxidant, with a consequent increase in serum oxidized LDL, malondialdehyde contributing to the occurrence of the disease.