Polyphenols profile and antioxidants capacity of Verbenaceae species from Burkina Faso

Abstract

Verbenaceae species are widely used in the traditional medicine to treat tumors, liver pathologies, hypertension and nervous hepatitis. The aim of this present study was to evaluate phenols and flavonoids chromatographic profile of 5 Verbenaceae species directed against antioxidant activities. 3 types of extracts were used in this evaluation such as decoction, acetone and EtOH-H2O extracts. Chemical composition was evaluated using aluminum chloride, Folin-Ciocalteu and HPLC-DAD methods. 3 antioxidant methods were used such as total antioxidant (TAC), iron reducing power (IRP) and radical scavenging activity (DPPH*). Principal component analysis (PCA) was used to research difference inside chemical polyphenolic compounds. High performance liquid chromatography with photodiode matrix, allowed us to reveal 56 polyphenolic compounds in different parts of the plant. The most represented compounds were Luteolin (7), Chlorogenic acid (5), Genkwanin (4), Rosmarinic acid (4), and Scutellarein-6,4'-dimethylether (4). The best total phenolsand flavonoids content was obtained with EtOH-H2O extract (111,255 mg GAE.g-1 of dry tissue) and (4.42 mg QE. g-1 of dry tissue), respectively. The best antioxidant activitiesweregiven in the order of EtOH-H2O > acetone and decoction extracts with Stachytarpheta angustifolia. The specific and qualitative profiles of each species allowed their separation or discrimination with principal component analysis. The relevant antioxidant properties, suggesting that different parts of the plant of Verbenaceae are an important source of natural antioxidants.