Evaluation of Secondary Metabolites and Antibacterial Potency of the Root Extract of Lemon balm (Lamiaceae) Vegetable against Multidrug Resistant Bacteria

Abstract

Lemon balm (Lamiaceae) vegetable is known for its aromatherapeutic properties is being used in curring many diseases. The aim of this study was to scientifically screen the medicinally active secondary metabolites and antibacterial potency of Lemon balm vegetable grown in Nigeria. Gas chromatography-mass spectrometry (GCMS) was used to analyse the extract while the antibacterial screening was carried out using agar-well diffusion method. Thirty-four (34) therapeutically active organic compounds were identified in the root extract with terpenoids and phenolic compounds representing the major class, including 2,3-bis[(9E)-9- octadecenoyloxy]propyl (9E)-9-octadecenoate (24.6%) as the major component, methyl (11E)-11-octadecenoate (11.7%), dipalmitin (10.7%), α-methyl-D-galactopyranoside (7.7%), eudesm-7(11)-en-4-ol (4.4%), 1,7,7- trimethylbicyclo[2.2.1]heptan-2-ol (3.0%), isoborneol (2.9%) and 2,6-cresotaldehyde (2.7%) as well as other minor compounds. The highest inhibitory effect of the root extract was observed against Proteus mirabilis which showed a zone of inhibition of 19 mm. The result evidently showed that the sample have several therapeutically active secondary metabolites that can be applied in the treating bacteria diseases.