Total phenolic content, total ascorbic acid and invitro antibacterial activity of ethanolic extract and essential oil of zingiber officinale (ginger) roots

摘要

Crude ethanolic extract and essential oil of Zingiber officinale (Ginger) roots were screened for their total phenolic content, total ascorbic acid and invitro antibacterial activity using standard methods. The total phenolic content of the essentialoil (6.98mgGAE/gDw) was higher than the ethanolic extract (3.39mgGAE/g Dw), the total ascorbic acid of the ethanolic extract (17.25mg/100gDw) was higher than the essential oil (14.49mg/100gDw) of the ginger roots. The antibacterial activity of the extract and oil was determined using the disc diffusion assay method. The diameter of inhibition zones ranged between 7.0±1.4and 10.0±1.1 (mm) forthe ethanolic extract and 7.1±3.4 and 11.0± 1.6 (mm) for the essential oil against the tested bacterial isolates. Staphylococcus aureus and Klebsiella pneumoniae were the most susceptible isolates to the extract and the oil while Streptococcus faecalis and E.coli were the more resistant to the crude ethanolic extract and essential oil. The results provided evidence that the extract and oil are indeed potential sources of natural antioxidants and antibacterial agents.