Abstract
Ethiopia’s healthcare system relies on traditional medicinal practices that use medicinal plants to treat human and livestock ailments. However, the lack of empirical validation regarding the efficacy of these treatments against specific infectious diseases necessitates rigorous scientific investigations. The objective of this study was to investigate the antibacterial activity and phytochemical screening on five selected medicinal plant species, namely
Solanum somalense
Franchet.,
Verbascum sinaiticum
Benth.,
Rumex nervosus
Vahl,
Withania somnifera
(L.) Dunal and
Calpurnia aurea
(Ait.) Benth. The plants were first identified jointly with local informants and later considering mainly their high informant consensus and fidelity level values for their efficacy in treating infectious diseases in the area. Ethanol and aqueous extracts were prepared from the plant materials, and their antibacterial activities were evaluated against standard bacterial strains, representing both gram-positive and gram-negative types. To assess the antibacterial activity of the extracts, the minimum inhibitory concentration (MIC) was determined using the broth dilution method. Additionally, phytochemical screening was performed using standard qualitative tests to identify various secondary metabolites. The results indicated antibacterial efficacy in the ethanol extracts of
S
.
somalense
,
W
.
somnifera
, and
C
.
aurea
against particular bacterial strains (
S
.
somalense
against
S
.
agalactiae
with MIC of 1.5 mg/mL;
W
.
somnifera
against
S
.
aureus
and
E
.
coli
, with MIC of 2 mg/mL;
C
.
aurea
against
E
.
coli
and
K
.
pneumoniae
, with MICs of 3 mg/mL and 3.5 mg/mL, respectively). The results of the phytochemical screening indicated the presence of steroids, alkaloids, flavonoids, saponins, and terpenoids. The selected medicinal plants demonstrated promising antibacterial activity against certain bacterial strains. The current findings support the long-standing claim of the traditional medical system of the study area for their continued use of these plants in their treatment of infectious diseases. Further investigation is required to isolate the responsible active compounds and characterize the constituents and description of their antibacterial effect for possible use in areas where these infectious diseases are major health problems.