EFFECT OF MAHARISHI AK-4 ON H2O2-INDUCED OXIDATIVE STRESS IN ISOLATEDRAT HEARTS

Oxidative damage to crucial biomolecules due to excess generation of r eactive oxygen species has been implicated as a major cause of organ d amage and hence compounds capable of negating such damage have potenti al benefits. Using hydrogen peroxide (H2O2) as a model pro-oxidant to induce oxidative stress, we have examined the ability of natural food supplement Maharishi Amrit Kalash (MAK-4) to decrease oxidative damage in potassium-arrested isolated rat hearts. The protocol was that hear ts isolated from male Sprague-Dawley rats were retrograde-perfused wit h Krebs-Henseleit (K-H) solution for 30 min for equilibration. After t his period, the hearts were subjected to cardioplegia with high potass ium (26-30 mM), followed by reperfusion with K-H solution in the prese nce or absence of 200 mu M H2O2. As expected, H2O2 treatment following cardioplegia induced a high degree of oxidative stress as assessed by release of lactate dehydrogenase (LDH, a marker of plasma membrane da mage) and total glutathione (GSH + GSSG). H2O2 also impaired the abili ty of heart to regain developed tension during the testing period. How ever, addition of MAK4 in the perfusate containing H2O2 decreased oxid ative stress in terms of release of LDH and glutathione. In parallel w ith these biochemical studies: in a few experiments the cardiac functi on was assessed by measuring developed contractile tension. These prel iminary studies also showed that in the presence of MAK-4 the H2O2-tre ated hearts were able to regain better developed tension. Further in v itro studies to examine the possible mechanisms of MAK-4 action reveal that this formulation contains H2O2 binding activity which resulted i n the decreased availability of H2O2 itself. Our studies hence reveal that the ayurvedic food supplement MAK-4 may have potential benefits i n reducing oxidative stress. (C) 1997 Elsevier Science Ireland Ltd.