Antimicrobial Activity of Essential Oil of <i>Zingiber officinale</i> Roscoe (Zingiberaceae)

Abstract

<i> Zingiber officinale </i> , commonly known as ginger, is a species native of tropical Asia. It is grown and used in tropical countries of America, including Mexico, where it is used for the treatment of throat infections. The aim of this study was to determine the chemical composition of essential oil of <i> Z. officinale </i> rhizome and evaluate their antimicrobial activity. The essential oil was obtained by hydrodistillation, and the chemical composition of the oil was determined by GC-MS. To determine the antimicrobial activity diffusion, agar dilution and radial growth inhibition methods were employed. Microbial growth curves were performed on the strains most susceptible. It was identified 28 compounds in the essential oil, the most abundant were eudesmol (8.19%), <i> γ </i> -terpinene (7.88 %), <i> a </i> -curcumene (7.28%), alloaromadendrene (6.56%), zingiberene (6.06 %), <i> α </i> -pinene (5.76 %), <i> δ </i> -cadinene (3.84%), elemol (3.39%), farnesal (3.45%), E- <i> β </i> -farnesene (3.57%), neril acetate (2.8%) and <i> β </i> -myrcene (2.94%). In antimicrobial activity, the essential oil inhibited the growth of 15 bacterial strains, 3 of yeast fungi and 4 of mycelia fungi. The most susceptible strains were <i> S. aureus </i> FES-I (MIC = 0.25 mg/mL) <i> S. epidemidis </i> FES-C (MIC = 0.5 mg/mL), <i> E. faecalis </i> ATCC 14506 (MIC = 1.0 mg/mL), <i> C. tropicalis </i> (CMI = 0.125 mg/mL) and <i> T. mentagrophytes </i> (CF ₅₀ = 0.08 mg/mL). In the microbial growth curves the essential oil showed bactericidal effect on <i> S. aureus </i> FES-I and <i> S. marcescens </i> ATCC 14756 from the first hour of exposure of the strains to oil, eliminating 99.9% of CFU in concentrations of 0.5 and 0.75 mg/mL respectively. The results validate the medicinal use of <i> Z. officinale </i> in the treatment of diseases of possible infectious origin.