Antimycobacterial, cytotoxic, and anti-inflammatory activities of Artemisia ludoviciana

Ethnopharmacological relevance: A third part of the world population has been exposed to the pathogen Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB). TB is a deadly disease, and its treatment has been hampered because of the lack of new antibiotics or the development of new antimycobacterial agents against this pathogen. The situation is aggravated because of the appearance of multidrug-resistant strains. In Mexican traditional medicine, records showed Artemisia ludoviciana for the treatment of TB. Thus, the combination of antibiotics and plant extracts might represent new antimycobacterial agents as an attractive alternative. Materials and methods: The biological activities of ethanol extract obtained from A. ludoviciana were evaluated for its antimycobacterial activities using an M. tuberculosis clinical isolate. Also, the toxicity of the extracts was assessed ex vivo and in vivo using the human-derived macrophages cell line (THP-1) and the Artemia spp. model, respectively. Lastly, the inflammatory response of macrophages exposed to the extracts was also evaluated. Results: The ethanol extract of A. ludoviciana showed antimycobacterial activity with a MIC of 250 mu g/mL against a clinical strain of M. tuberculosis. Ex vivo cytotoxicity using the THP-1 cell line incubated with the ethanol extract showed an IC50 of 20 mu g/mL. On the other hand, the Artemia model's toxicity test showed moderate toxicity when the A. ludoviciana extract was tested with LC50 of 195.64 mu g/mL. Analysis of the inflammatory response of THP-1 cells exposed to the same extract showed no increase in secreted interleukine-6 and -10. Also, no effect was observed in the pro-inflammatory tumor necrosis factor-a cytokine level. Moreover, a chemical profile of the extracts identified achillin as the major component in the ethanol extract, along with other minor components such as thuj one and stigmasterol. Conclusions: We showed that the ethanol extract of A. ludoviciana possessed antimycobacterial activity and could potentially be used to supplement the antibiotic treatment of TB.