Therapeutic Potential of Allicin from Garlic (Allium sativum L.) as an Adjunctive Therapy against Multi-Drug Resistant Tuberculosis: Narrative Literature Review

Background: Tuberculosis (TB), particularly Multidrug-Resistant Tuberkulosis (MDR-TB), remains a global public health challenge due to the long duration of treatment, systemic toxicity, and increasing bacterial resistance. These conditions necessitate adjuvant therapy. Allicin (diallyl thiosulfinate), a bioactive organosulfur compound derived from garlic (Allium sativum L.), possesses broad-spectrum antimicrobial activity and has the potential to be developed as an antituberculosis adjuvant. Research Objective: To evaluate the therapeutic potential, molecular mechanisms, intracellular efficacy, pulmonary vapor dynamics, and safety profile of allicin against Mycobacterium tuberculosis. Research Methods: This study is a narrative literature review. A structured literature search was conducted via PubMed, ScienceDirect, Web of Science, and Google Scholar to synthesize the latest microbiological, biochemical, and pharmacological evidence. Results: Allicin exhibits antimicrobial effects primarily through rapid thiol-disulfide exchange reactions with essential cysteine residues and depletion of intracellular glutathione (GSH), thereby inducing disulfide stress and disrupting cellular redox homeostasis. In vitro studies and macrophage infection assays demonstrate promising antimicrobial activity of allicin and thiosulfinate-rich garlic extracts, although direct evidence against MDR-M. tuberculosis remains limited. Allicin’s moderate lipophilicity and instability support the development of pulmonary delivery via inhalation or lipid-based nanocarriers to minimize first-pass metabolism in the liver. Although allicin exhibits cytotoxicity near the Minimum Inhibitory Concentration (MIC) in cell cultures, extracellular GSH may provide a protective buffering effect in lung tissue. Conclusion: Allicin is a promising adjuvant candidate for MDR-TB, but clinical translation remains limited by thermal instability, rapid inactivation, a lack of direct evidence in MDR-Mycobacterium tuberculosis, and study heterogeneity. Further preclinical and clinical research is needed to determine optimal efficacy, safety, formulation, and route of administration.