Evaluation of Antibacterial Activity of Some Traditionally Used Medicinal Plants against Human Pathogenic Bacteria

Table 2

Minimum inhibitory concentration (MIC, g/mL) of ethanol plant extracts and reference antibiotics against bacteria.

Plant species	Gram-negative bacteria										Gram-positive bacteria
	ESBL-EC	Ec	Vc	Cf	MDR-ST	Ecl	IRPA	Stm	Se	ESBL-KP	MRSA	Ef	Sa	Sp	Sal
Acorus calamus	—	—	3125	—	12500	—	6250	—	—	—	—	6250	—	3125	6250
Adhatoda vasica	—	6250	—	—	—	—	—	—	—	—	—	—	—	12500	12500
Artemisia vulgaris	—	—	3125	—	6250	—	6250	6250	—	6250	3125	6250	3125	391	—
Asparagus racemosus	—	—	—	—	12500	—	6250	—	—	—	—	12500	—	391	—
Centella asiatica	—	—	—	—	—	—	—	—	—	—	12500	—	6250	3125	12500
Cinnamomum camphora	—	6250	6250	—	—	—	—	781	—	3125	—	3125	3125	49	—
Curculigo orchioides	—	—	12500	—	—	6250	12500	—	—	6250	12500	—	12500	49	—
Curcuma longa	—	6250	1562	—	—	—	—	—	—	—	6250	98	3125	195	6250
Cuscuta reflexa	—	12500	1562	—	6250	12500	6250	—	—	6250	12500	12500	6250	781	—
Cynodon dactylon	1562	781	781	—	1562	6250	781	1562	6250	391	391	—	195	781	3125
Drymaria cordata	—	—	6250	—	—	12500	6250	6250	—	6250	12500	—	6250	3125	12500
Eupatorium adenophorum	—	12500	12500	—	6250	—	3125	—	—	6250	3125	3125	3125	6250	—
Ginkgo biloba	—	—	—	—	—	—	—	—	—	—	12500	12500	6250	6250	12500
Psidium guajava	—	—	12500	3125	6250	6250	781	3125	6250	3125	6250	3125	6250	3125	—
Rauwolfia serpentina	—	12500	—	12500	—	6250	3125	6250	—	6250	6250	6250	6250	3125	3125
Swertia chirayita	—	12500	12500	—	—	3125	—	—	—	12500	6250	—	6250	—	—
Gentamicin^a	64	<1	<1	32	<1	16	64	<1	<1	64	—	—	—	—	—
Vancomicin^b	—	—	—	—	—	—	—	—	—	—	<1	<1	<1	<1	<1

“—”: not tested because plant extracts did not show the inhibitory effect by agar-well diffusion method or not suitable to test (for reference drug); Cf: Citrobacter freundii; Ecl: Enterobacter cloacae; Ef: Enterococcus faecalis, Ec: Escherichia coli (25922); ESBL-EC: extended-spectrum β-lactamase-producing Escherichia coli; ESBL-KP:extended-spectrum β-lactamase-producing-Klebsiella pneumoniae; IRPA: imipenem-resistant Pseudomonas aeruginosa, Sa: Staphylococcus aureus (ATCC 25923); MRSA: methicillin-resistant Staphylococcus aureus; Sal: Streptococcus agalactiae; Se: Salmonella enteritidis; Sp: Streptococcus pyogenes; MDR-ST: multidrug-resistant Salmonella typhi; Stm: Salmonella typhimurium; Vc: Vibrio cholerae. Gentamicin and vancomycin were used as reference drugs for Gram-negative bacteria and Gram-positive bacteria, respectively.
a and b = Reference drugs used for the Gram-negative and Gram-positive bacteria, respectively.