Leaves and stem bark from Allophylus africanus P. Beauv.: An approach to anti-inflammatory properties and characterization of their flavonoid profile.

Food Chem Toxicol. 2018 May 19;118:430-438. doi: 10.1016/j.fct.2018.05.045. [Epub ahead of print] Ferreres F1, Gomes NGM2, Valentão P3, Pereira DM4, Gil-Izquierdo A5, Araújo L6, Silva TC7, Andrade PB8. Author information 1 Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS (CSIC), P.O. Box 164, 30100 Campus University Espinardo, Murcia, Spain. Electronic address: federico@cebas.csic.es. 2 REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal. Electronic address: ngomes@ff.up.pt. 3 REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal. Electronic address: valentao@ff.up.pt. 4 REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal. Electronic address: dpereira@ff.up.pt. 5 Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS (CSIC), P.O. Box 164, 30100 Campus University Espinardo, Murcia, Spain. Electronic address: angelgil@cebas.csic.es. 6 Quilaban SA, Beloura Office Park, Edifício 11, Quinta da Beloura, 2710-693 Sintra, Portugal. Electronic address: luisaaraujo@quilaban.pt. 7 REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal. Electronic address: atcsilva92@gmail.com. 8 REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal. Electronic address: pandrade@ff.up.pt. Abstract The small tree Allophylus africanus, widespread in the African continent, has long been considered valuable, as noted by the number of reports on their multiple medicinal uses. With this work, we aimed to extend the current, and so far restricted, knowledge on the chemical composition of the plant, particularly as source of flavonoids, as well as to assess its potential anti-inflammatory properties. The chemical characterization of the aqueous extract obtained from the leaves allowed the identification and quantitation of 30 flavones, predominantly apigenin derivatives, but also four luteolin derivatives, while the stem bark extract was solely characterized by apigenin di-C-glycosides and mono-C-glycosides-O-glycosylated. Strong inhibitory effects towards 5-lipoxygenase were observed with the aqueous extracts obtained from the leaves and stem bark, with IC50 values of 41.28 and 107.77 μg mL-1, respectively. Both extracts were also found to reduce NO levels in LPS-challenged RAW 264.7 macrophages, without noticeable cytotoxicity. The flavonoid profile of the plant is disclosed for the first time, allowing the identification of several molecules that may contribute to mitigate the inflammatory response. Jointly, with the current study the anti-inflammatory use of the leaves and stem bark is partially validated. KEYWORDS: Cymaroside; Inflammation; Medicinal plants; Vicenin-2; Vitexin; Vitexin 2″-O-Rhamnoside PMID: 29787847 DOI: 10.1016/j.fct.2018.05.045