Abstract:
The present study was conducted to investigate the antibacterial activities of roots of
Carissa spinarm and Cissampelos mucronata. The plants were collected from Bench
Maji zone in Bero woreda, southwest of Ethiopia. Root parts of the two plants were air
dried under shade and the dehydrated roots were separately crushed into fine texture
using mortar, and further grinded into powder using electronic grinder machine. Crude
extracts were prepared using 100 g of powdered roots using methanol, acetone and
petroleum ether. Microbial activities of different concentration of the extracts were
evaluated against standard strains of Staphylococcus aureus (ATCC25923), Escherichia
coli (ATCC 25922), Pseudomona aeruginosa (ATCC 27853) and Salmonella
typhimurium ATCC 133110) following the disc diffusion method and micro broth
dilution assay. Phytochemical screening of plant extracts was also conducted following
standard methods. Result of the current study indicated that the methanol extract of root
of C.mucronata had better inhibitory activity with maximum inhibition zone of 19 mm
against Staphylococcus aureus (ATCC25923) and 17 mm against Salmonella
typhimurium (ATCC 133110). In the case of Carissa spinarm, the methanol extract was
more effective with inhibition zones diameter of 14 mm and 11 mm against
Staphylococcus aureus (ATCC25923) and Pseudomona aeruginosa (ATCC 27853),
respectively. Accordingly, methanol extracts of the root of C. spinarm was relatively
more effective against Gram positive bacteria than Gram negative bacteria. The result of
phytochemical screening revealed the presence of saponin, flavonoids, tannins and
terpenoids although at different intensity. The minimum inhibitory concentrations
(MIC) of the three extracts ranged from 6.5 mg/ml to 25 mg/ml. The root of
Cissampelos mucronata extracts exhibited better antimicrobial activity than the root
extract of Carissa spinarm.
