Phytochemical Characterization and Bioactive Properties of Cinnamon Basil (Ocimum basilicum cv. 'Cinnamon') and Lemon Basil (Ocimum x citriodorum)

The aim of this work was to contribute to the knowledge on the chemical composition and bioactive properties of two species of the Ocimum genus, namely O. basilicum cultivar 'Cinammon' and O. x citriodorum. For this purpose, samples of these plants grown in Portugal were evaluated for their composition in phenolic and volatile compounds, and the infusion and hydroethanolic extracts were assessed for their in vitro antioxidant, antimicrobial, cytotoxic, and anti-inflammatory activities. In total, the two basil samples showed the presence of seven caffeic acid and derivatives (dimers, trimers, and tetramers) and five flavonoids, mainly glycoside derivatives of quercetin. Despite some qualitative and quantitative differences, in both samples rosmarinic acid was the major phenolic compound, and linalool the predominant volatile compound. In general, the tested extracts provided relevant bioactive properties since both basil species showed higher antioxidant activity in Thiobarbituric Acid Reactive Substances (TBARs) and Oxidative Hemolysis Inhibition (OxHLIA) assays when compared with the positive control Trolox. Despite O. x citriodorum extracts showing slightly better activity against some strains, both types of extracts evidenced similar antimicrobial activity, being more active against Gram-positive bacteria. The extracts also revealed interesting cytotoxicity, particularly the O. x citriodorum hydroethanolic extract which was also the only one exhibiting anti-inflammatory activity.