BIOACTIVE COMPOSITION AND ANTIOXIDANT PROPERTIES OF AROMATIC HERBS FROM THE LAMIACEAE FAMILY: BASIL (Ocimum basilicum L.) AND OREGANO (Origanum vulgare)

Most Lamiaceae family species are widely applied in culinary to enhance sensory attributes, being also reported as medicinal plants in several folk traditions. Therefore, their popular use has attracted researchers’ attention to their bioactive antioxidant constituents. Thus, this study characterized the bioactive composition and antioxidant capacity of basil (Ocimum basilicum L.) and oregano (Origanum vulgare). The extracts were analyzed by their total content of phenolic compounds and flavonoids, as well as by DPPH and FRAP assays. Moreover, bioactive compounds were determined by UHPLC-ESI-MS analyses. The total phenolic contents of basil and oregano extracts were 8.00 ± 0.75 and 11.21 ± 0.20 mg GAE/g, respectively. Oregano also showed higher levels of flavonoids (34.25 ± 0.21 mg QE/g) compared to basil (12.35 ± 0.74 mg QE/g). Regarding the DPPH assay, inhibitions of 89.36 ± 0.48 and 37.82 ± 0.09% were assessed for oregano and basil, respectively, while basil showed the highest ferric-reducing activity (217.36 ± 1.14 μmol ET/g). UHPLC-ESI-MS analyses characterized phenolic acids and flavonoids. Seven phenolic acids were determined: p-hydroxybenzoic acid (m/z 137), p-coumaric acid (m/z 163), vanillic acid (m/z 167), caffeic acid (m/z 179), caftaric acid (m/z 311), salvianolic acid F isomers (m/z 313), and rosmarinic acid (m/z 359). Caffeic acid and salvianolic acid F isomers were found in both extracts. Caftaric, p-coumaric, and rosmarinic acids were found only in basil extract, while oregano showed vanillic and p-hydroxybenzoic acids. Moreover, cirsilineol (m/z 343) was detected in basil. Compounds identified in both herbs are of considerable interest due to their bioactivities, specialty their antioxidant properties that are mainly due to phenolic compounds. Thus, these herbs may be highlighted as important nutritional elements for health promotion. Besides, they present a great combination of sensory attributes and antioxidant properties, representing promising food additives that must also be natural alternatives to synthetic antioxidants.