Biologic Propensities and Phytochemical Profile of Vangueria madagascariensis J. F. Gmelin (Rubiaceae): An Underutilized Native Medicinal Food Plant from Africa

Table 4

Results of preliminary antimicrobial screening of the plant extracts (50 mg/mL) using disc diffusion method.

Test microorganisms	Gram stain +/−	Standard^b	Diameter of zone of inhibition (mm)^a
			Decoction^c				Methanol^c
			S1	S2	S3	S4	S1	S2	S3	S4
Staphylococcus aureus	G+	26.33 ± 0.58	—	—	10.67 ± 1.15^d	—	11.67 ± 1.53^d	—	—	8.33 ± 1.53^d
Escherichia coli	G−	21.67 ± 3.79	—	12.67 ± 0.58^d	—	—	10.00 ± 2.00^d	—	—	—
Pseudomonas aeruginosa	G−	15.33 ± 1.53	—	—	—	—	—	—	—	—
Aspergillus niger	F	23.00 ± 1.00	—	—	—	—	—	—	—	—
Candida albicans	F	20.67 ± 0.58	—	—	—	—	—	—	—	—

aNo. of replicates (n = 3) for each sample; values are given as mean ± SD. ^bTested at a concentration of 10 µg/disk (Oxoid), bacteria, ampicillin; fungi, nystatin. ^cS1: leaf, S2: unripe fruit, S3: ripe fruit, S4: seed. ^dValues significantly lower (P < 0.05) from positive control, standard antibiotic (One way ANOVA, post hoc Tukey). G+, Gram positive; G−, Gram negative; F, fungi; (−), no distinct zone of inhibition.