Determining Antimycobacterial Activity

IC₅₀ determination was carried out using M. smegmatis strain mc²155 cells grown in 7H9 media (Difco, Middlebrook from Becton Dickinson and Company, Sparks, MD, USA) having 0.2% glycerol and 0.05% Tween 80 and supplemented with 10% OADC^{43 (link)}. Appropriate dilutions (0 to 500 µM) of both naringenin (N5893) and quercetin (Q4951); Sigma-Aldrich, St Louis, MO, USA, were added to the 7H9 media containing M. smegmatis cells and incubated for 48 hours and 72 hours in an assay volume of 200 μl and IC₅₀ values were calculated by using MTT assay (M6494; Invitrogen, Life Technologies). Ethambutol was used as a positive control. The values were calculated from at least three independent experiments and represented as Mean ± S.E.M. Obtained IC₅₀ concentration at 48 hours was used for all the subsequent experiments.