EFFECT OF A RADIOSENSITISER,WITHAFERIN A ,ON THE FREE RADICAL METABOLISING ENZYMES OF NEUTROPHILS, IN CARCINOMA OF UTERINE CERVIX SUBJECTED TO RADIOTHERAPY

Abstract

Radiosensitisation influences the enzymes of free radical metabolism.These enzymes are
also a part of the respiratory burst mechanisms. Withaferin,an active component obtained
from the dried root extracts of withania somnifera(ashwagandha),showed radiosensitising
effects in animals. Hence, a study of the respiratory burst enzymes namely NADPH
oxidase ,Myeloperoxidase, Glutathione,Glutathione peroxidase,Glucose 6 phosphate
dehydrogenase and Superoxide dismutase were undertaken in leukocytes of patients with
carcinoma of uterine cervix , which would perhaps aid in the understanding of
radiosensitising mechanisms of Withaferin and increase the therapeutic outcome in
cancer patients. Blood samples were collected from stage IIIB carcinoma of uterine cervix
patients(n=20), before starting treatment(baseline),after 15 days and after 30 days of
treatment with RT and Withaferin. Age and sex matched controls(n=25)were also
considered for comparison. A significant decrease in NADPH oxidase was observed in
baseline samples of cancer patients when compared to controls. Except for this variation,
there was no change in the activities of other enzymes, when cancer patients were
compared to controls or when baseline values were compared with that of follow up
samples, in case of patients. This study therefore implies that radiosensitising actions of
withaferin may not be mediated through free radical metabolism.