LDH activity in different drug groups treated with AZA. The cells were cultured for 12 h with each of the anti-tuberculosis drugs (isoniazid, INH; pyrazinamide, PZA; INH + rifampicin, RIF; or INH + RIF + PZA) or their combination with AZA (10 μM). LDH enzyme activity was detected using the micro-enzyme method. Each group included 6 parallel samples, each of which was measured 3 times.