Different species belonging to the genus Lycopodium L. (Lycopodiaceae) were used in folk medicine due to their antibacterial, healing effects on wounds, and properties used in the treatment of mental diseases, like amnesia, schizophrenia and different types of dementia. Extracts containing volatiles obtained from different Lycopodium species: L. clavatum, L. annotinum, and Huperzia serrata (syn. Lycopodium serratum Thunb.), were tested against Mycobacterium tuberculosis. Dichloromethane and petroleum ether extracts of the mentioned species collected in different geographical sites (in Poland and Ukraine) have shown interesting activities. Minimal Inhibitory Concentrations (MIC) values for the extracts were determined by a 96-well microplate method with alamarBlue (Invitrogen). The inoculum of the reference strain of Mycobacterium tuberculosis H37Ra in Middlebrook 7H9 broth (Difco) was 5 x 105 cfu/mL per well, according to CLSI standards. Serial twofold dilutions of the extracts ranged from 8 to 256 µg/mL. As the internal control of the method, serial twofold dilutions of four first-line antibiotics dedicated to tuberculosis treatment: isoniazid (INH), rifampicin (RMP), ethambutol (EMB), and streptomycin (SM) were used [1,2]
