Abstract:
Ehretia cymosa (Boraginaceae) is an indigenous plant widely distributed in different parts of
Ethiopia where it is locally called Game in Amharic and Hulaga, Ulaga, Garmi in Afan Oromo.
The overall objective of this study is phytochemical investigation, antibacterial and antioxidant
activities of the root bark extracts of Ehretia cymosa. Root barks of Ehretia cymosa was
successively extracted by n-hexane, chloroform and methanol. The percentage yield of n hexane, chloroform and methanol crude extract of root bark of Ehretia cymosa was 2%, 1.02%,
3.29% respectively. n-hexane crude extract subjected to column chromatography which
furnished the mixed compound-CIH1 were most likely similar to mixture of α-amyrin, β-amyrin,
bauerenol and β-sitosterol, and compound-C2H2 was compared with α-amyrin based on their
spectroscopic data IR and NMR (1H-NMR, 13C-NMR and DEPT-135). The n-hexane,
chloroform, methanol extract and mixed compound-C1H1(α-amyrin, β-amyrin, bauerenol and
β-sitosterol) were assessed for their antibacterial activities. The results showed that the n hexane extract(200mg/mL) exhibited activities against Escherichia coli, Staphylococcus
aureus, Klebsiella pneumoniae and pseudomonas aeruginosa with zone of inhibition of
20mm,20mm, 14mm and 20mm, respectively. The chloroform extract(200mg/mL) exhibited
activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and
pseudomonas aeruginosa with zone of inhibition of 19, 19.5, 16mm and 16mm, respectively.
The methanol extract(200mg/mL) exhibited activities against Escherichia coli, Staphylococcus
aureus, Klebsiella pneumoniae and pseudomonas aeruginosa with zone of inhibition
10mm,15mm,15mm and 25mm, respectively. Mixed compound-C1H1(α-amyrin, β-amyrin,
bauerenol and β-sitosterol) (200mg/ml) exhibited activities against Staphylococcus aureus,
Klebsiella pneumoniae with zone of inhibition 12mm and 13mm and respectively. But no
activities against two pathogens pseudomonas aeruginosa and Escherichia coli. Furthermore,
the n-hexane, chloroform, MeOH extract and mixed compound-C1H1(α-amyrin, β-amyrin,
bauerenol and β-sitosterol) at 40mg/ml were found to inhibit DPPH radical by 79%, 75%, 83%
and 41%, respectively.
