Antibacterial activity of essential oils from Indian medicinal plants in vapor phase

Karolína Hvězdová

Bakalářská práce

Abstract:

Pathogenic bacteria, such as Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes, can cause severe respiratory diseases. Inhalation therapy based on the administration of antibacterial agents directly to the site of infection might be one of the possible treatments for respiratory tract infections. The antibacterial activity can be exhibited by essential oils (EOs), which are produced by the plants as secondary metabolites. The objective of this thesis was to evaluate the antimicrobial activity of EOs obtained from the Indian medicinal plants, namely Cinnamomum camphora, Cymbopogon citratus, Cyperus scariosus, Eucalyptus globulus, Ocimum gratissimum, Piper longum, Psidium guajava, Trachyspermum ammi, and Syzygium cumini against potentially pathogenic microorganisms of the respiratory tract (H. influenzae, S. aureus, S. pneumoniae, S. pyogenes). The EOs were obtained by hydrodistillation, then the antimicrobial activity was assayed using the broth microdilution volatilization method. Minimum inhibitory concentrations (MICs) were determined for both liquid and vapor phases. The results showed that out of the 9 EOs tested only 3 produced positive effects against at least one of the bacteria strains in liquid or vapor phases. Trachyspermum ammi showed the highest growth-inhibitory effect against H. influenzae with MICs from 128 µg/mL to 256 µg/mL in the liquid and vapor phase, respectively. Cymbopogon citratus was the second most effective EO with MIC 256 µg/mL in both phases. S. aureus was slightly susceptible to all 3 EOs with MICs ≥ 256 µg/mL. S. pneumoniae and S. pyogenes were resistant to EOs tested with MIC values > 512 µg/mL. EOs have relatively low efficacy and therefore their application in practice is quite limited. However, these findings might be improved with further investigation. The plant volatile agents could also be tested for other microorganisms.

Keywords

Antibacterial activity, Essential oil, Indian medicinal plants, Vapor

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 15. 4. 2022

Obhajoba závěrečné práce

• Vedoucí: prof. Ing. Ladislav Kokoška, Ph.D.

Česká zemědělská univerzita v Praze

Fakulta tropického zemědělství

Bakalářský studijní program:
Tropické zemědělství