Melissa officinalis: Antibacterial and Antioxidant Potential, Phenolic Profile and Enzyme Activities

Abstract

Popularly referred to as lemon balm, Melissa officinalis L., has been used as a cure for gastrointestinal disorders, respiratory and cardiovascular diseases, mental and central nervous system problems, various cancers, headache, nervousness, and rheumatism. In this study, the phenolic profile, antioxidant potential, antibacterial activity, and enzyme activity of lemon balm grown in nature in Bolu, Turkey were determined. Furthermore, comparisons were made with plants grown in vitro. Individual phenolic analysis with HPLC-DAD showed that the most prevalent phenol was rosmarinic acid in both extracts and naturally-grown plants had higher amount than in vitro-grown ones. Similarly, naturally-grown plants had considerably greater levels of total phenol-flavonoid, scavenging activity for free radicals (DPPH), and phenol synthesis related enzyme (PAL). As for the enzymatic antioxidant activity (SOD and CAT), naturally-grown plants were found to have higher CAT activity and lower SOD activity. As a remarkable result, although plants grown in vitro showed moderate antibacterial activity, no effect was observed in naturallygrown plants. In general, these results showed that the M. officinalis grown in nature is exposed to more biotic and abiotic stress and increases their phenolic content remarkably and consequently antioxidant capacity.