Artemisia species are important traditional medicinal plants of Ethiopia which are used for the treatment of infection and non-infection health problems. The genus Artemisia (Astraceae) consists of about 500 species worldwide. In this study, the main aim was to investigate chemical components of Artemisia spp. (A. abyssinica, A. absinthium and A. annua) and evaluate their antimicrobial activities against bacterial strains. The results indicated that the crude extract of these plants was effective against selected bacterial strains. Here we isolated the well-known antimalarial drug artemisinin (7 mg, 0.004%) from Artemisia annua leaves using a rapid n-hexane fractionation method. The n-hexane extract of A. abyssinica, ethyl acetate extract of A. absinthium and n-hexane of A. annua showed varying degrees of inhibiting effect against bacterial strains such as Staphylococcus aureus ATCC 25923 T, Salmonella enteritidis ATCC13076T, Klebsiella pneumoniae ATCC1053T, boydii ATCC1233T, Escherichia coli ATCC 25922 T, hospital acquired Acinetobacter baumannii. The ethyl acetate extract of Artemisia absinthium (A.abe) showed the maximum inhibiting effect (35 mm) against A. baumannii. The minimum zone of inhibition (< 3 mm) was recorded for test extract of A.ap against Klebsiella pneumoniae ATCC1053T. Ethyl acetate extract of A, absinthium (A.abe) was more effective against these selected bacterial strains and the zone of inhibition ranged from 5 to 35 mm. The minimum inhibition zone (8 mm) was detected against S. typhimurium ATCC 13311 T for both A.ac and n-hexane- EtOAc fraction (8:2) of A, abyssinica. The maximum zone of inhibition (25 mm) for fraction (A.ach F4) of A, abyssinica obtained by column chromatography was recorded against S. pyogen ATCC 19,615. However, there was no zone of inhibition detected for boydii ATCC1233T due to these test extracts. Significant variations (P ≥ 0.05) were observed between all test extracts of these medicinal plants at 95% of confidence intervals. In this study, clear zones of inhibition were detected for the positive control (standard impregnated disks). Based on our results we recommend that various species of Artemisia spp. seem to have the potential for in-depth investigation for various antimicrobial activities that assisting the effort in searching for antimicrobial lead compounds.

Artemisia spp are one of the most important traditional medicinal plants of Ethiopia which are used for the treatment of infection and non-infection health problems. The genus Artemisia (Astraceae) consists of about 500 species worldwide. Previous reports indicated that the different species of Artemisia have a wide array of biological activities including antimalarial, cytotoxic, antihepatotoxic, antibacterial, antifungal and antioxidant activity. In this study, the main aim was to investigate chemical components of Artemisia spp. (A. abyssinica, A. absinthium and A. annua) and evaluate their antimicrobial activities against bacterial strains. The results indicated that the crude extract of these plants were effective against some selected strains of bacterial strains. Here we isolated the well-known antimalarial drug artemisinin (7 mg, 0.004%) from Artemisia annua leaves using a rapid n-hexane fractionation method. The n-hexane extract of A. abyssinica, ethyl acetate extract of A. absinthium and n-hexane of A. annua showed varying degrees of inhibiting effect against bacterial strains such as Staphylococcus aureus ATCC 25923T, Salmonella enteritidis ATCC13076T, Klebsiella pneumoniae ATCC1053T, boydii ATCC1233T, Escherichia coli ATCC 25922T, hospital acquired Acinetobacter baumannii. The ethyl acetate extract of Artemisia absinthium (A.abe) showed the maximum inhibiting effect (35 mm) against A. baumannii. The minimum zone of inhibition (< 3 mm) was recorded for test extract of A.ap against Klebsiella pneumoniae ATCC1053T. Ethyl acetate extract of Artemisia absinthium (A.abe) was more effective against these selected bacterial strains and the zone of inhibition ranged from 5-35 mm. The minimum inhibition zone (8 mm) was detected against S. typhimurium ATCC 13311T for both A.ac and n-hexane- EtOAc fraction (8:2) of Artemisia abyssinica. The maximum zone of inhibition (25 mm) for fraction (A.ach F4) of Artemisia abyssinica obtained by column chromatography was recorded against S. pyogen ATCC 19615. However, there was no zone of inhibition detected for boydii ATCC1233T due to these test extracts. Significant variations (P = 0.887) were observed between all test extracts of these medicinal plants at 95% of confidence intervals. There is no zone of inhibition or growth for negative control. But, clear zones of inhibition were detected for positive control due to some standard impregnated disks. Based on our results we recommend that various species of Artemisia seem to have great potential for in-depth investigation for various antimicrobial activities that assists the effort in searching for antimicrobial lead compounds.