Effects of antituberculous agents on nitric oxide synthesis by human macrophages induced by virulent mycobacterium tuberculosis (H37Rv)

Abstract

The present study was carried out to determine the effects of isoniazid, rifampicin, streptomycin and ethambutol on the nitric oxide (NO) synthesis by human macrophages induced by Mycobacterium tuberculosis H37Rv. Human macrophages were obtained by Ficoll-Hypaque density gradient method, dispersed into the microplate wells (105 macrophages/well) and incubated at 37°C overnight. The next day, M. tuberculosis H37Rv suspensions (104 cfu/ml per well) were added into the wells and after incubation at 37°C for one hour, the antibiotic solutions which will be studied were added. The NO synthesis has been evaluated by measuring the nitrite levels with Griess reagent at 3rd, 6th, 24th and 48th hours of the culture supernatants. In each trial, the control wells containing macrophages alone and macrophages + M. tuberculosis, were included to the study. As a result, nitrite levels were found to be increased by virulent M.tuberculosis (H37Rv) and the nitrite level in the isoniazid well was detected significantly higher than the other antibiotic wells, statistically (p<0.05).