Phytochemical characterization, antioxidant and antibacterial activity of essential oil and extracts of Tagetes patula on Staphylococcus aureus

Abstract

Tagetes patula is an ornamental plant species and its essential oils contain potentially allelopathic active ingredients. The objective of the present study was to evaluate the phytochemical composition of extracts, the antioxidant and antibacterial activity of the essential oil of flowering leaves of the species, on Staphylococcus aureus. For this, the extraction of the essential oil by hydrodistillation was carried out, evaluating the physical characteristics (solubility, density and refractive index) and phytochemical characteristics of the extracts through a phytochemical screening (alkaloids, flavonoids, phenols, saponins, tannins and reducing sugars). The quantificatics of phenols in the essential oil was performed by the Folin Ciocalteu method, the antioxidant activity using the DPPH and ABTS tests, the antimicrobial activity by determining the minimum inhibitory concentration. The results obtained showed for the essential oil, a density of 0,733 g.mL-1, refractive index of 1,47 and insolubility in ethanol (70 %), presence of tannins, flavonoids and phenols in the extracts. The phenolic content was 1.024 ± 0,19 mg.g-1 TAE, the antioxidant activity with DPPH was 87,6 ± 0,18 µmol.g-1TE and with ABTS 180,83 ± 0,36 µmol.g-1 TE in Trolox equivalent. The minimum inhibitory concentration was 16,67 mm against S. aureus, in response to which it is concluded that the essential oil of T. patula had antioxidant activity against radicals DPPH and ABTS, high phenolic contents and showed antibacterial activity in vitro tests against S. aureus.