Fig. 6

Time dependent and concentration – dependent bactericidal effect of alkaloid extracts from C. zeyheri on M. smegmatis. Cultures of M. smegmatis standardised to 1 x 10⁶ cfu/ml were exposed to alkaloid extracts from C. zeyheri at 2-fold increasing concentrations from 2 μg/ml to 1000 μg/ml over 24 h at 37 ̊C. After 2, 4, 6, 8 and 24 h of exposure samples were taken to determine number of surviving populations at 0, 63, 125, and 250 μg/ml