DENISA ȘTEFANIA MANOLESCU*^,**, GEORGIANA UȚĂ*^,**^#, A. DIN*, SPERANȚA AVRAM**

*Regional Research and Development Center for Innovative Materials, University of Pitești, Products, and Processes from Automotive Industry, Argeș, Romania

** Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania

Melissa officinalis L. (lemon balm) has been used since ancient times for its remarkable curative properties (anti-inflammatory, antidepressant, digestive, carminative, tonic or diuretic). These properties are due to the polyphenols that abound in the body of this plant species. In the present work, we aimed to determine the influence of particle size of macerated powders on the antioxidant activity and the extraction process of these polyphenols as well as the in silicostudy of one of the most abundant polyphenols of this plant species, namely caffeic acid. The results obtained indicate a significant Trolox equivalent antioxidant capacity (TEAC) of 2.31 μg/mL correlated with the highest amount of total polyphenols content (TPC) of 52.26 ±0.36 mg gallic acid equivalent per g of dry plant (mg GAE/g dry plant) for the macerates obtained with a pharmaceutical ethyl alcohol content of 50 % of the powder with average particle size (106–90 μm). The in silico analysis of caffeic acid revealed that natural compound exhibits good intestinal permeability and blood-brain barrier (BBB) permeability, but shows moderate bioactivity correlated with the probability of binding to a relatively small number of molecular targets.

Key words: lemon balm., particle size, antioxidants, in silico studies, caffeic acid.