Primary screening test, the qualitative antibacterial assay revealed that out of the nine different extracts, only methanol extract of A. paniculata leaves posses antibacterial activity against S. aureus ATCC 25923. The methanol extracts of leaves from other two plants, A. maculatum and T. cardifolia exhibited no activity against the pathogens tested (Table 1).
Table 1. Antibacterial activity of different plant extracts by agar well diffusion.
Plant leaves Extraction solvent Amount of extract Zone of inhibition in mm against
S. aureus ATCC 25923 E. coli ATCC 35218 Tinospora cardifolia Water 100 μl = 1.0 mg ND ND Methanol ND ND Hexane ND ND Arum macculatum Water ND ND Methanol ND Hexane ND Andrographis paniculata Water ND ND Methanol 14 ND Hexane ND ND
ND = Not detected.