Adjunctive antimycobacterial and immunomodulatory effects of Allium cepa (pink variety) in a rabbit model of latent-like mycobacterial infection.

INTRODUCTION

Latent tuberculosis infection (LTBI) represents a major global reservoir for active disease, characterized by persistent, metabolically inactive bacilli that are difficult to eradicate. Novel therapeutic approaches targeting bacterial persistence and host immune responses are needed.

METHODS

A rabbit model of latent-like mycobacterial infection was established using aerosolized Mycobacterium aurum. The rabbits were treated with isoniazid and rifapentine (HR), ethanolic extract of Allium cepa (EAC), and combination therapy. Treatment efficacy was evaluated using colony-forming unit (CFU) counts and haematological parameters (WBC, neutrophils, lymphocytes).

RESULTS

The CFU counts increased significantly during the induction phase, confirming successful establishment of the latent-like mycobacterial infection model, while stabilization of bacterial load over time suggested immune-mediated containment. During the treatment phase, significant reductions in CFU counts were observed in all treated groups compared with untreated controls (p < 0.0001), with the greatest reduction seen in combination therapy groups (HR + Allium cepa extract), indicating an improved efficacy relative to monotherapy. Haematological analysis revealed significant increases in WBC, neutrophils, and lymphocytes during infection, reflecting immune activation. Treatment resulted in normalization of WBC counts, reduction in neutrophilia, and stabilization of lymphocyte levels, indicating attenuation of inflammation and restoration of immune balance.

CONCLUSION

Allium cepa demonstrated antimycobacterial and immunomodulatory effects in a rabbit model of latent-like mycobacterial infection and may have potential as an adjunctive therapeutic strategy in LTBI management.