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

Abstract

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.