Potential of Basil (Ocimum basilicum L.) as bioactive ingredient and natural preserver

Basil (Ocimum basilicum L.) is a much appreciated plant, both for culinary purposes and for health treatments. It is used in many dishes and is also known for its properties as an appetite stimulant, carminative, and diuretic. It is also used as a mouth wash to cure inflammations. These bioactive properties could be correlated with its phenolic fraction. In this work the polyphenols present in both the infusion and decoction of basil, detected through HPLC-DAD-ESI/MS, are reported, along with the antitumor, antimicrobial and antioxidant activities. Among the polyphenols, rosmarinic acid was the main phenolic acid, and quercetin-3-O-rutinoside the main flavonoid. With regard to the antitumor properties, five cell lines were tested (MCF7, NCI-H460, HeLa, HepG2). The infusion showed a moderate activity against NCI-H460, HeLa and HepG2, while the decoction only showed activity against HeLa and HepG2. None of the extracts showed hepatotoxicity for non-tumour porcine liver cells (PLP2). In terms of antimicrobial activity, the results were very interesting. Regarding the bacterial strains, both the decoction and iníüsion revealed similar results, with Staphylococcus aureus, and Micrococcus flavus being the most sensitive species, with minimum inhibitory concentrations lower for the extracts than the positive controls. In terms of the antifungal activity both extracts were very effective against Asperguulus ochraceus, Aspergillus niger, Trichoderma viridae and Penicillium ochrochloron with minimum inhibitory concentrations lower than the positive controls for both extracts. Regarding the antioxidant activity, both the extracts yielded very similar results, and the effects were as follows: thiobarbituric acid reactive substances inhibition (TBARS) > reducing power > 2,2-diphenyl-l-picrylhydrazyl (DPPH) scavenging activity > (β-carotene bleaching inhibition. These results place basil as a very interesting matrix to be added to foodstuffs due to its good taste, but also as a functional and/or preserver ingredient, given its high antioxidant and antimicrobial activities. Furthermore, our research group is testing this plant as a functional ingredient and natural preserver in "Serra da Estrela" cheese.