Phytochemical Characterization and Evaluation of Bioactive Properties of Tisanes Prepared from Promising Medicinal and Aromatic Plants

The chemical composition and biological properties correlation in several medicinal and aromatic plants is still underexplored, especially in its most common form of consumption as tisane. The present study aims to characterize the organic acids and vitamin E composition of five tisanes and their extracts by High-Performance Liquid Chromatography coupled to a diode-array detector (HPLC-DAD) and HPLC coupled to a fluorescence detector techniques, respectively, and the phenolic composition by HPLC-DAD-ESI/MS (mass spectrometry by electrospray ionization). It also focuses on their bioactive properties, namely antioxidant, antimicrobial, anti-inflammatory, cytotoxic, anti-tyrosinase, and anti-diabetic activities. A Principal Component Analysis (PCA) was performed in order to understand the correlation between the chemical composition and bioactive properties of the tisanes. The tisane 5 (T5) composed by lemon thyme, tutsan, cloves, and cinnamon, was the most promising mixture, presenting the lowest values for the lipid peroxidation inhibition, anti-inflammatory, and anti-diabetic activity. It also presented the highest concentration of phenolic acids (caffeoylquinic acids derivatives), and flavan-3-ols (catechin derivatives). Only the dry plants presented tocopherols. For the antihemolytic, antimicrobial, and cytotoxic activity, T2 and T4 (with lemon thyme) were highlighted as the best herbal mixtures. The PCA proved to be a valid tool to select the most promising tisane according to the bioactivity. These results suggest that the studied tisanes can be source of high added-value bioactive compounds with health-promoting effects and potential for application in the food and nutraceutical industries, among others.