Ameliorative Effects of He:Ne Laser Irradiation on DNA Damage of Blood of Children with Acyanotic Heart Disease

Abstract
Low-energy laser irradiation (LELI) has been found to attenuate various biological
processes in tissue culture and experimental animal models. The aim of the present study was
to investigate the role of LELI in ameliorating markers of oxidative stress (in terms of blood
antioxidant enzymes levels, NO generation, apoptotic genes together with DNA
fragmentation and apoptosis percentage in circulating lymphocytes) in cyanotic and acyanotic
congenital heart diseases with reference to normal healthy children. Accordingly, whole
blood from 16 cyanotic, 14 acyanotic and 15 controls was exposed to 8 mW He-Ne laser at
energy densities of 3 J/ cm2 and examined before, after and without laser exposure 24 hours
post irradiation for levels blood antioxidant enzymes, NO generation, Bax RNA and Bcl2
protein together with DNA fragmentation and apoptosis percentage in circulating
lymphocytes. Results indicated that there were significant increases in mean ± SD of plasma
nitrite, MDA, DNA fragmentation and apoptosis in circulating lymphocytes of both acyanotic
and cyanotic cases compared to controls before laser irradiation. Laser ameliorated oxidative
stress in acyanotic heart disease blood, but increased apoptosis and DNA fragmentation in
cyanotic cases 24 hours post laser irradiation. In control cases laser had a biostimulatory
effect exhibited by decreased lipid peroxidation, apoptosis and DNA fragmentation
compared to its level without laser irradiatioin. Also, there was significant increase in plasma 
nitrite in controls, cyanotic and acyanotic cases 24 hours post irradiation with laser compared
to their level without laser irradiation. However, cyanotic cases showed the highest
significant value and were significantly higher when compared to both cyanotic and acyanotic
cases. It is concluded that He:Ne laser have an ameliorative effect on damaging effects
induced due cardiac catheterization procedure in case of acyanotic congenital heart diseases,
but it worsen the effects in cyanotic congenital heart diseases. Increased nitric oxide
production seems to be the reason for the increased oxidative stress in cyanotic heart diseases,
which are worsened when exposed to laser irradiation.