Ruellia angustiflora (Nees) Lindau ex Rambo: extraction and characterization of phenolic compounds and evaluation of antiradical, photoprotective and antimicrobial activities

Abstract

Ruellia angustiflora is a shrub popularly known as flower of fire, used in traditional medicine as a healing agent. This study aims to verify the presence of characteristics of pharmaceutical interest in extracts from the root, stem and leaves of this species. The ideal time for ultrasound-assisted extraction is 60 min with a solid-liquid ratio of 1% (w/v). The kinetics of the reaction of the extracts with DPPH is biphasic, and IC₅₀ values are related to the total phenolic compounds. Five phenolic compounds were identified in the extracts, where ferulic acid, rutin and quercetin showed to be the main responsible for the antiradical activity. The extracts displayed considerable photoprotective activity, mainly Ra-LE (SPF = 23). Ra-RE showed an inhibition halo similar to erythromycin against Streptococcus pyogenes. Taken together, these data reveal that Ruellia angustiflora is a source of phenolic compounds and has relevant antiradical, photoprotective and antibacterial activities.

Graphical Abstract

Keywords:

• Ruellia angustiflora
• antiradical activity
• DPPH-HPLC
• natural sunscreens
• antimicrobial activity

Acknowledgments

We thank all the co-authors for their collaborations and to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the scholarships.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The funds are from a CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) scholarship, and the information has been added in the acknowledgments.