Phytochemical screening, phenolic and flavonoid contents, antioxidant and cytogenotoxicity activities of Combretum leprosum Mart. (Combretaceae)

ABSTRACT

Combretum leprosum Mart. (Combretaceae), a shrub popularly known as mofumbo, is used in folk medicine for treatment of uterine bleeding, pertussis, gastric pain, and as a sedative. The aim of this study was to (1) determine the phytochemical profile,(2) identify chemical constituents and (3) examine antioxidant and cytogenotoxic activity of ethanolic extracts and fractions of stem bark and leaves. The plant material (leaf and stem bark) was submitted to extraction with ethanol, followed by partition using hexane, chloroform, and ethyl acetate. It was possible to identify and quantify the epicatechin in the ethanolic stem bark extract (0.065 mg/g extract) and rutin in the leaf extract (3.33 mg/g extract). Based upon in vitro tests a significant relationship was noted between findings from antioxidant tests and levels of total phenolic and flavonoid. Comparing all samples (extracts and fractions), the ethyl acetate fractions of stem bark (411.40 ± 15.38 GAE/g) and leaves (225.49 ± 9.47 GAE/g) exhibited higher phenolic content, whereas hexanic fraction of stem bark (124.28 ± 56 mg/g sample) and ethyl acetate fraction of leaves (238.91 ± 1.73 mg/g sample) demonstrated a higher content of flavonoids. Among the antioxidant tests, the intermediate fraction of stem bark (28.5 ± 0.60 μg/ml) and ethyl acetate fraction of leaves (40 ± 0.56 μg/ml) displayed a higher % inhibition of free radical DPPH activity, whereas intermediate fraction of stem bark (27.5 ± 0.9 μg/ml) and hydromethanol fraction of leaves (81 ± 1.4 μg/ml) demonstrated inhibition of the free radical ABTS. In biological tests (Allium cepa and micronucleus in peripheral blood), data showed that none of the tested concentrations of ethanolic extracts of leaves and stem bark produced significant cytotoxicity, genotoxicity, and mutagenic activity.Abbreviations AA%: percentage of antioxidant activity; ABTS: 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid); CEUA: Ethics Committee in the Use of Animals; TLC: Thin Layer Chromatography; DNA: deoxyribonucleic acid; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ROS: Reactive oxygen species; EEB: ethanol extract of the stem bark; HFB: Hexanic fraction of stem bark; IFB: Intermediate fraction of stem bark; CFB: Chloroform fraction of stem bark; EAFB: Ethyl acetate fraction of stem bark; HMFB: Hydromethanol fraction of the stem bark; EEL: Ethanol extract from leaves; HFL: Hexane fraction of leaves; CFL: Chloroform fraction of leaves; EAFL: Ethyl acetate fraction of leaves; HMFL: Hydromethanol fraction of leaves; GAE: Gallic Acid Equivalent; IC₅₀: 50% inhibition concentration; HCOOH: Formic acid; HCl: hydrochloric acid; HPLC: High-performance liquid chromatography; MN: micronucleus; WHO: World Health Organization; UFLC: Ultra-Fast Liquid Chromatography; UESPI: State University of Piauí.

KEYWORDS:

• Chemical constituents
• antioxidant
• cytogenotoxic
• combretum leprosum

Authors’ contributions

Conceptualization and design: Sousa, H.S.; Uchôa, V.T; Cavalcanti, S.M.G; De Almeida, P. M.; Provision of study materials and funding acquisition: Cavalcanti, S.M.G; De Almeida, P. M.; Chaves, M.H.; Lima Neto, J.S.; Nunes, P.H.M; Da Costa Júnior, J.S.; Collection and assembly of data: Sousa, H.S.; Do Carmo, I.S.; De Sousa, E.A. Data analysis and interpretation: Sousa, H.S.; Uchôa, V.T; Cavalcanti, S.M.G; De Almeida, P. M. Writing – original draft and editing: Sousa, H.S.; Uchôa, V.T; Cavalcanti, S.M.G; De Almeida, P. M.; Rai, M. Supervision and project administration: Sousa, H.S.; Uchôa, V.T; Cavalcanti, S.M.G; De Almeida, P. M.

Acknowledgments

We would like to thank the Research Supporting Foundation of the State of Piaui (FAPEPI/Brazil) and Uespi for financial support. In addition, we would like to thank the Federal University of Piauí (UFPI) and Federal Institute of Piauí (IFPI) for providing the research facilities and everyone who contributed to this work. CAPES and CNPq.

Disclosure statement

The authors have declared that there is no conflict of interest.

Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.