Anti-inflammatory and Antioxidant Effects of Melissa officinalis Extracts: A Comparative Study

Melissa officinalis L. (MO), traditionally referred to as lemon balm, is one of the lemon-scent aromatic herbs widely used in traditional medicine due to its calming, sedative, and anti-arrhythmic effects. Furthermore, several studies have linked its therapeutic potential with its antioxidant properties. Here, we aimed to evaluate and compare the content of active components, antioxidant, and anti-inflammatory potential of three different MO extracts (MOEs), ethanolic macerate (E1), aqueous (E2), and ethanolic (E3), obtained under reflux and their effects on systemic redox status after acute per os administration in vivo post-carrageenan application. The HPLC analysis revealed that the most abundant constituent in all the three extracts was rosmarinic acid (RA), with higher content in E1 and E3 than in E2 (P < 0.05). The highest flavonoid content was found in the aqueous extract, especially quercetin (P < 0.05). For the carrageenan-induced paw edema model, dark agouti rats were used and divided into the groups: Control, indomethacin, E1, E2, and E3 subgrouped according to applied doses: 50,100, and 200 mg/kg. Ethanolic macerate (E1200) and aqueous (E2100) MOE were shown to be anti-inflammatory agents in the carrageenan paw edema model, with the most prominent edema inhibition in the sixth hour post-carrageenan (63.89% and 69.44%, respectively, vs. 76.67% in the indomethacin group). All the three extracts reduced the production of pro-oxidants H2O2 and TBARS post-carrageenan and increased GSH levels compared to control (P < 0.05). These data imply the possible future usage of MOEs to prevent inflammatory and oxidative stress-related diseases.