Screening of the Dichloromethane: Methanolic Extract of Centella asiatica for Antibacterial Activities against Salmonella typhi, Escherichia coli, Shigella sonnei, Bacillus subtilis, and Staphylococcus aureus

Table 1

Zones of inhibition produced by the C. asiatica extract against bacteria strains in mm.

Group	Zones of inhibition (mm)
	Treatment	Staphylococcus aureus	Escherichia coli	Salmonella typhi	Bacillus subtlis	Shigella sonnei
Negative control	DMSO	6.00 ± 0.00^d	6.00 ± 0.00^f	6.00 ± 0.00^e	6.00 ± 0.00^d	6.00 ± 0.00^d
Positive control	Tetracycline	29.33 ± 0.67^a	26.67 ± 0.33^a	27.67 ± 0.33^a	22.67 ± 0.33^a	25.33 ± 0.33^a
C. asiatica DCM: MeOH extract	15.625 mg/ml	6.00 ± 0.00^d	6.00 ± 0.00^f	6.00 ± 0.00^e	6.00 ± 0.00^d	6.00 ± 0.00^d
	31.25 mg/ml	6.00 ± 0.00^d	6.00 ± 0.00^f	6.00 ± 0.00^e	6.00 ± 0.00^d	6.00 ± 0.00^d
	62.5 mg/ml	6.00 ± 0.00^d	7.33 ± 0.33^e	6.00 ± 0.00^e	6.00 ± 0.00^d	6.00 ± 0.00^d
	125 mg/ml	6.00 ± 0.00^d	8.67 ± 0.33^d	8.00 ± 0.33^d	6.00 ± 0.00^d	7.33 ± 0.33^d
	250 mg/ml	9.67 ± 0.33^c	13.67 ± 0.33^c	10.67 ± 0.33^c	7.67 ± 0.33^c	9.00 ± 0.58^c
	500 mg/ml	12.00 ± 0.58^b	16.33 ± 0.33^b	13.00 ± 0.58^b	9.67 ± 0.33^b	15.67 ± 0.33^b

Values are expressed as mean ± standard error of the mean (SEM) for triplicate reading. Values with the same superscript letter in the columns are not significantly different by one-way ANOVA followed by Tukey’s post-hoc test.