Antibacterial Activities of Five Medicinal Plants in Ethiopia against Some Human and Animal Pathogens

Abstract

Objective To evaluate the in vitro antibacterial activities of five plant extracts which have been used as traditional medicines by local healers against three multidrug resistant bacteria, namely, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Results The highest mean zone of inhibition (4.66 mm) was recorded from methanol extract of Calpurnia aurea (Ait.) Benth. at a concentration of 200 mg/ml against S. aureus, followed by Croton macrostachyus Del. (4.43 mm) at the same dose and solvent for the same bacterial species, while methanol and chloroform extracts of E. brucei Schwein. did not inhibit growth of any bacterial species. The lowest value (100 μg/ml) of minimum inhibitory concentration (MIC) was observed from both methanol and chloroform extracts of C. aurea (Ait.) Benth. against all the three bacteria. The results of the positive control had no statistically significant difference (P > 0.05) when compared with crude extracts of C. aurea (Ait.) Benth. at concentration of 200 mg/ml against S. aureus. Conclusion The results of the present study support the traditional uses of these medicinal plants by the local healers. Except Erythrina brucei Schwein., all the plants investigated in this study exhibited antibacterial activities against the test bacterial species. Further researches are needed to be conducted to evaluate efficacy of these medicinal plant species on other microbes in different agroecological settings and their safety levels as well as their phytochemical compositions.

The Potential Antibacterial and Antifungal Activities of Wood Treated with Withania somnifera Fruit Extract, and the Phenolic, Caffeine, and Flavonoid Composition of the Extract According to HPLC

“…W. somnifera extracts have been demonstrated to possess strong antifungal and antibacterial activities [18][19][20][21][22]. Acetone root-bark extract from Salvadora persica has been shown to be very effective at stopping the bacterial growth of Agrobacterium tumefaciens and Dickeya solani [23], and leaf aqueous extract has been observed to inhibit the mycelial growth and spore germination of some plant pathogenic fungi [24].…”

An in Vitro Assessment of the Anti-Aeromonas Properties of Leaf Extract Obtained From Ficus Lyrata Warb. (Moraceae)

“…Ficus species demonstrated low inhibition of P. aeruginosa, with inhibition zone diameter values of 3 mm (F. benghalensis and F. tisela ethanolic extracts) and 2 mm (F. racemosa ethanol extract). Aqueous extracts of all Ficus species and both extracts of F. religiosa appeared inactive against P. aeruginosa [22].…”

“…Further studies (Nair and Chanda, 2007) tested aqueous and ethanol extracts from ten Indian plant species, including the same species of Ficus (F. benghalensis, F. racemosa, F. religiosa, and F. tisela), against several medically important bacterial strains (Alcaligenes faecalis ATCC 8750, Bacillus cereus ATCC 11778, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis NCIM 2241, Salmonella typhimurium ATCC 23564, and Staphylococcus aureus ATCC 25923). The ethanol extracts were more potent than aqueous extracts of all the plants studied.…”

Potential of Antibacterial Compounds from Sweet Root Extract (Glycyrrhiza glabra L) on Bacillus cereus

“…Hasil penelitian ini berbeda dengan yang dilakukan oleh Gupta et al, (2013) yaitu ekstrak baru mulai menunjukan sensitivitasnya ketika konsentrasi sampel 50% [19]. Perbedaan nilai KHM ini kemungkinan disebabkan oleh kandungan senyawa antibakteri yang berbeda disetiap pelarut [20] dan juga dipengaruhi tempat tumbuh tanaman serta jenis pelarut yang digunakan saat proses ekstraksi [21]. Tabel Hasil organoleptik menunjukkan bahwa sifat dari ekstrak etanol akar manis memiliki bentuk ekstrak kental, warna coklat kehitaman, aroma seperti cengkeh, rasanya manis dan lengket.…”