Fig. 7: Ornithine and imidazole restrict Mtb growth in the lungs.

C57BL/6 mice were infected with 100 CFU of aerosolized Mtb H37Rv, and then treated with ornithine and imidazole at varying concentrations. a Schematic representation of Mtb infection and intranasal delivery of the compounds. b, c Bacterial burden in the lungs measured after one-month post-infection and post-treatment. Data are representative of three independent experiments (n = 5 mice per group). Data are expressed as the mean ± SD. p < 0.0015. c Mtb-infected mice were treated in combination of ornithine/imidazole, one group treated with 1000/100 mg/kg, other as 2500/300 mg/kg and last group as 5000/600 mg/kg. p < 0.0029. d–f At one-month post-infection and post-treatment, the lungs of the uninfected control, Mtb-infected, ornithine or imidazole treated mice were isolated and formalin-fixed. Paraffin-embedded tissue sections were prepared, and hematoxylin and eosin staining was performed. Inflamed lung areas were compared among the groups. d A representative figure is shown. e Percentage of the lung lesions was calculated. p < 0.0024, p < 0.0192. f Paraffin-embedded lung tissue sections were analyzed by confocal microscopy to evaluate LC-3B (green), F4/80 (far-red) staining as well as their colocalization. Scale bar: 10 μm. A representative micrograph of LC-3B in lungs is shown. Images of multiple fields at 63× magnification were taken with oil immersion. g The immunofluorescence intensity (A.U.) of LC-3B are shown. Data are representative of three independent experiments. Five mice per group were used for each independent experiment. p < 0.0013. Statistical analysis was performed using paired two-tailed t test and data are represented as the mean ± SD.