Abstract
2-Styrylchromones (2-SC) are a group of oxygen-containing heterocyclic compounds, which are characterized by the attachment of a styryl group to the C-2 position of their chromone core. Over the years, several biological activities have been attributed to 2-SC, such as antioxidant, anti-inflammatory, antimicrobial, antiviral, and antitumor activities [1,2]. Nonetheless, there are no reports in the literature about the effect of 2-SC on human neutrophils’ oxidative burst. Therefore, the present study aims to evaluate the modulation of human neutrophils’ oxidative burst by a panel of hydroxylated 2-SC, previously obtained by chemical synthesis, and to analyze the structure–activity relationship [3]. For that purpose, freshly isolated neutrophils from human blood were stimulated with phorbol-12-myristate-13-acetate, and a chemiluminescence method was applied to evaluate the oxidative burst, using luminol as a probe [4]. Considering the OH substituents present on the B-ring of 2-SC, the tested compounds can be divided into the following three groups: group 1, with a catechol group (C-3′ and C-4′); group 2, with an OH at C-4′; group 3, without any substitution on the B-ring. The 2-SC from group 1 were the most active, with IC50 values in the order of 1 µM. In conclusion, the catechol B-ring appears to play an important role in the modulation of human neutrophils’ oxidative burst by 2-SC.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ECB2021-10283/s1, Poster S1: Nutraceuticals_Nano_Nutraceuticals_and_Nano_Pharmaceuticals_10283_Modulation_of_human_neutrophil_slides; Video S1: Nutraceuticals_Nano_Nutraceuticals_and_Nano_Pharmaceuticals_10283_Modulation_of_human_neutrophil_slides.
Author Contributions
Conceptualization, E.F. and D.R.; methodology, M.L.; validation, E.F. and D.R.; formal analysis, M.L.; investigation, M.L.; writing—original draft preparation, M.L.; writing—review and editing, M.L., M.F., A.M.S.S., E.F. and D.R.; supervision, A.M.S.S., E.F. and D.R.; project administration, E.F. and D.R.; funding acquisition, E.F. and D.R. All authors have read and agreed to the published version of the manuscript.
Funding
This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project UIDB/50006/2020 and from the European Union (FEDER funds through the Operational Competitiveness Program (COMPETE2020) POCI-01-0145-FEDER-029253—Project PTDC/MED-QUI/29253/2017).
Institutional Review Board Statement
The study was conducted according to the guidelines of the Declaration of Helsinki, and was approved by the Ethics Committee of Centro Hospitalar Universitário do Porto/Instituto de Ciências Biomédicas Abel Salazar, Oporto, Portugal.
Informed Consent Statement
Informed consent was obtained from all subjects involved in the study.
Data Availability Statement
The data presented in this study are available on request from the corresponding author.
Acknowledgments
Mariana Lucas thanks FCT and ESF (European Social Fund) for her Ph.D. grant (2021.06746.BD). Marisa Freitas further acknowledges the contract under the Scientific Employment Stimulus—Individual Call (CEEC Individual) 2020.04126.CEECIND/CP1596/CT0006.
Conflicts of Interest
The authors declare no conflict of interest.
References
- Gomes, A.; Freitas, M.; Fernandes, E.; Lima, J.L.F.C. Biological activities of 2-styrylchromones. Mini Rev. Med. Chem. 2010, 10, 1–7. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Santos, C.M.M.; Silva, A.M.S. An overview of 2-styrylchromones: Natural occurrence, synthesis, reactivity and biological properties. Eur. J. Org. Chem. 2017, 22, 3115–3133. [Google Scholar] [CrossRef] [Scilit]
- Santos, C.M.M.; Silva, A.M.S.; Cavaleiro, J.A.S. Synthesis of New Hydroxy-2-styrylchromones. Eur. J. Org. Chem. 2003, 23, 4575–4585. [Google Scholar] [CrossRef] [Scilit]
- Ribeiro, D.; Freitas, M.; Tomé, S.M.; Silva, A.M.S.; Porto, G.; Fernandes, E. Modulation of human neutrophils’ oxidative burst by flavonoids. Eur. J. Med. Chem. 2013, 67, 280–292. [Google Scholar] [CrossRef] [Scilit] [PubMed]
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