Antibacterial and Antioxidant Activities of Lemon Balm (Melissa officinalis L.) Essential Oil

Lemon balm (Melissa officinalis L.) belongs to the Lamiaceae family. Essential oil extracted from the aerial parts of lemon balm has been investigated for the protection of fruits during storage, as insecticidal, as well as in medicine, due to its bioactive properties. In this paper, the composition and identification of components from Melissa officinalis L. essential oil were determined by gas chromatography coupled with mass spectrophotometry (GC/MS) analysis. Total phenol content (TPC) and the scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2′-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS+·) free radicals were evaluated by UV-VIS spectrometry. Antibacterial activities were carried out against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Seventeen bioactive compounds were found as constituents of Melissa officinalis L. essential oil, among which o-cymene (19.735%), dehydro-p-cymene (17.180%), and limonene (11.589%) were found as the major components. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) provided a confirmation for the chemical components of lemon balm essential oil identified by GC/MS. The values recorded for TPC and antioxidant activity were as follows: 54.72 mg GAE/g dry substance, 28.53% for DPPH, and 46.17% for ABTS assays, respectively. 100 µL lemon balm essential oil proved total antibacterial activity against the tested microorganisms. The results showed that the Melissa officinalis L. may be a good candidate as plant-derived antioxidant and antibacterial agent for medical footwear, wound dressings and other medical applications.