Shenling Baizhu Powder Alleviated Lung Damage and Enhanced Immunoregulatory Activity in Mice with Non-Tuberculosis...

To investigate the effects of Shenling Baizhu Powder (SLBZP) on non-tuberculous mycobacteria (NTM)-induced lung disease in mice.

An NTM lung disease mouse model was established by Mycobacterium kansasii infection. C57BL/6J female mice were randomly divided into 5 groups by a random number table (n=6): negative control, NTM, SLBZP-L (2.34 g/kg), SLBZP-H (4.68 g/kg), and rifampicin (20 mg/kg). M. kansasii load in the lungs, liver, and spleen was quantified. Lung histology was performed using hematoxylin and eosin staining. Gene and cytokine expressions related to CD4⁺ T and natural killer (NK) cells were detected by enzyme linked immunosorbent assay, flow cytometry, real-time quantitative reverse transcription PCR, and Western blot, respectively.

SLBZP-L and SLBZP-H treatments inhibited M. kansasii growth and reduced the histological damage and granuloma lesion areas in lungs of mice (P<0.01). SLBZP-H increased interleukin (IL)-17A and interferon-gamma (IFN-γ) levels, along with the proportion of CD4⁺ T cells, NK cells, and IFN-γ⁺ NK cells, while decreased IL-10 (P<0.01). Furthermore, SLBZP-H inhibited mRNA levels of tumor necrosis factor, IL-6, IL-1β, C-C motif chemokine ligand 2, C-X-C motif chemokine ligand (CXCL) 2, GATA binding protein 3 and T-bet, and increased mRNA level of retinoic acid receptor-related orphan receptor γ (P<0.05 or P<0.01). SLBZP-L and SLBZP-H also reduced the protein expressions of CXCL13 and C-X-C chemokine receptor type 5 (P<0.05 or P<0.01).

SLBZP alleviated NTM-induced lung damage and enhanced NK cell immune response, which might be linked to CD4⁺ T cell immunity.