Isolation and characterization of bioactive xanthones from Hippocratea africana (Willd.)Loes.ex Engl. (Celastraceae). (15th November 2021)

• Record Type: Journal Article
• Authors: Umoh, Uwemedimo F.; Thomas, Paul S.; Essien, Emmanuel E.; Okokon, Jude E.; De Leo, Marinella; Ajibesin, Kola' K.; Flamini, Guido; Eseyin, Olorunfemi A.
• Is Part Of: Journal of ethnopharmacology. Volume 280(2021)
• Publication Date: 2021-11-15
• Subjects: Hippocratea africana -- Xanthones -- Analgesic -- Anti-inflammatory -- Antioxidant; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2021.114031
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Ethnopharmacological relevance: Hippocratea africana root is used in African folk medicine for the treatment of several ailments, including pain and inflammation. Aim of the study: To isolate anti-inflammatory and analgesic compounds from the roots of H. africana, with accompanying antioxidant potentials. Materials and methods: Dichloromethane, ethyl acetate, and aqueous fractions of H. africana roots, and isolated compounds from the bioactive ethyl acetate fraction were evaluated for anti-inflammatory and analgesic activities using the xylene induced oedema in mice and thermal induced pain models, respectively. The antioxidant potentials of isolated compounds were tested in 2, 2-diphenyl-1-picryhydrazyl radical and ferric reducing antioxidant power assays. Structures were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR experiments, ionization mass spectrometry, and comparison with literature data. Results: Isoathyriol (1, 3, 7-trihydroxy-6-methoxyxanthone) and norathyriol (1, 3, 6, 7-tetrahydroxyxanthone) were isolated from the potent anti-inflammatory and analgesic ethyl acetate fraction of H. africana roots. Isoathyriol and norathyriol demonstrated good anti-inflammatory, analgesic, and antioxidant properties compared with the standards used in each assay. Conclusions: This study substantiates the use of H. africana root extract in the alleviation of inflammation and pain, and reports the characterization of secondary metabolites in H. africana and for the first time the presence of xanthones in Hippocratea genus. Graphical abstract: Image 1 Highlights: Hippocratea africana root is traditionally used in Africa against pain and inflammation. H. africana root extract acts as anti-inflammatory, analgesic, and antioxidant. Xanthones from roots have anti-inflammatory, analgesic, and antioxidant effects. Results validate the anti-inflammatory use of H. africana root in ethnomedicine. Xanthones in H. africana and in the genus are reported for the first time.