Antioxidant, antimicrobial and wound healing properties of Struthanthus vulgaris

Struthanthus vulgaris (Vell.) Mart. (Loranthaceae) has been widely used in traditional medicine in Brazil to bathe wounds.

The objective of this study is to investigate the in vitro wound healing effects, together with the antioxidant and antimicrobial activities of S. vulgaris leaf and branch extracts.

Ethanol leaf and branch extracts of S. vulgaris were investigated at 1-100 µg/ml concentrations in the scratch assay after 14 h. Antioxidant activity was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay, and the antibacterial activity was tested at concentrations up to 1000 µg/ml against Gram-positive and Gram-negative bacteria by the microdilution test after 24 h. The total phenolic and flavonoid contents were determined by colorimetric methods.

Struthanthus vulgaris leaf and branch extracts at 100 µg/ml concentration stimulated migration and proliferation of fibroblasts and enhanced cell numbers by 56.2% and 18.6%, respectively. Antioxidant activity exhibited IC50 values of 24.3 and 18.9 µg/ml for the leaf and branch extracts, respectively. The ethanol leaf extract showed antimicrobial activity against the Gram-positive Staphylococcus mutans and Staphylococcus aureus bacteria, exhibiting minimum inhibitory concentration values of 125 and 500 µg/ml, respectively. An appreciable total phenolic content in the leaves (813.6 ± 2.7 mg/g) and branches (462.8 ± 9.6 mg/g), and relatively low concentration of flavonoids in the leaves (13.3 ± 4.3 mg/g) and branches (1.9 ± 0.2 mg/g), was detected.

The antioxidant and antibacterial activities, together with the strong ability to stimulate proliferation and migration of fibroblasts, provide some support for the traditional use of S. vulgaris.