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. 2022 Sep 15;27(18):6027.
doi: 10.3390/molecules27186027.

Spectroscopic Analysis of an Antimalarial Drug's (Quinine) Influence on Human Serum Albumin Reduction and Antioxidant Potential

Affiliations

Spectroscopic Analysis of an Antimalarial Drug's (Quinine) Influence on Human Serum Albumin Reduction and Antioxidant Potential

Wojciech Rogóż et al. Molecules. .

Abstract

Quinine (Qi) is a well-known drug used in malaria therapy; it is also a potential anti-arrhythmic drug used in the treatment of calf cramps, rheumatoid arthritis, colds, and photodermatitis. Moreover, it is used in the food industry for the production of tonics. This study aimed to analyze the interaction between quinine and a transporting protein-human serum albumin (HSA)-as well as the influence of Qi on both protein reduction and antioxidant potential. It was found that Qi (via spectrofluorometric measurements and circular dichroism spectroscopy) binds to HSA with a low affinity and slightly affects the secondary structure of albumin. As demonstrated by the use of ABTS and FRAP assays, HSA has a higher antioxidant and reduction potential than Qi, while their mutual interaction results in a synergistic effect in antioxidant activity and reduction potential.

Keywords: antioxidant and reduction potential; human serum albumin; quinine; spectroscopy.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Absorption spectra of analyzed ligand–protein mixtures: (a) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:1 molar ratio; (b) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:2 molar ratio; (c) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:4 molar ratio; (d) “Qi”, “Qicalc 1:1 molar ratio”, “Qicalc 1:2 molar ratio” and “Qicalc 1:4 molar ratio”; [Qi] 7 × 10−5 M, [HSA] 7 × 10−5 M, 1.4 × 10−4 M, 2.8 × 10−4 M; all tested solutions were prepared in phosphate buffer (pH 7.4).
Figure 1
Figure 1
Absorption spectra of analyzed ligand–protein mixtures: (a) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:1 molar ratio; (b) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:2 molar ratio; (c) “Qi”, “HSA”, “Qi-HSAcomplex” and “Qicalc = Qi-HSAcomplex − HSA” at ligand:protein 1:4 molar ratio; (d) “Qi”, “Qicalc 1:1 molar ratio”, “Qicalc 1:2 molar ratio” and “Qicalc 1:4 molar ratio”; [Qi] 7 × 10−5 M, [HSA] 7 × 10−5 M, 1.4 × 10−4 M, 2.8 × 10−4 M; all tested solutions were prepared in phosphate buffer (pH 7.4).
Figure 2
Figure 2
Spectrofluorimetric analysis: (a) the fluorescent emission spectra of HSA ([HSA] 3 × 10 −6 M): without or in the presence of Qi ([Qi] 1 × 10−3 M); λex 285 [nm]; (b) the Klotz plot for HSA in the presence of Qi at Qi:HSA molar ratio from 0.67:1 to 6.67:1. In the insert: quenching of HSA fluorescence by Qi at Qi:HSA molar ratio from 0.67:1 to 6.67:1; λex 285 nm; [HSA] 3 × 10−6 M; [Qi] 1 × 10−3 M; pH = 7.4.
Figure 2
Figure 2
Spectrofluorimetric analysis: (a) the fluorescent emission spectra of HSA ([HSA] 3 × 10 −6 M): without or in the presence of Qi ([Qi] 1 × 10−3 M); λex 285 [nm]; (b) the Klotz plot for HSA in the presence of Qi at Qi:HSA molar ratio from 0.67:1 to 6.67:1. In the insert: quenching of HSA fluorescence by Qi at Qi:HSA molar ratio from 0.67:1 to 6.67:1; λex 285 nm; [HSA] 3 × 10−6 M; [Qi] 1 × 10−3 M; pH = 7.4.
Figure 3
Figure 3
The value of % inhibition of Qi ([Qi] = 7 × 10−5 M), HSA ([HSA] = 2.8 × 10−4 M) and Qi-HSAcomplex (1:4 molar ratio; [Qi] = 7 × 10−5 M; [HSA] = 2.8 × 10−4 M); Ex: expected, De: designated (DPPH assay); pH = 7.4.
Figure 4
Figure 4
The structural formula of Qi (ChemSketch 12.1.0.31258).

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References

    1. Achan J., Talisuna A.O., Erhart A., Yeka A., Tibenderana J.K., Baliraine F.N., Rosenthal P.J., D’Alessandro U. Quinine, an old anti-malarial rug in a modern world: Role in the treatment of malaria. Malar. J. 2011;10:144. doi: 10.1186/1475-2875-10-144. - DOI - PMC - PubMed
    1. Jones R.A., Panda S.S., Hall C.D. Quinine conjugates and quinine analogues as potential antimalarial agents. Eur. J. Med. Chem. 2015;97:335–355. doi: 10.1016/j.ejmech.2015.02.002. - DOI - PubMed
    1. Permin H., Norn S., Kruse E., Kruse P.R. On the history of Cinchona bark in the treatment of Malaria. Dan. Medicinhist. Arbog. 2016;44:9–30. - PubMed
    1. Rogerson S.J. Management of malaria in pregnancy. Indian J. Med. Res. 2017;146:328–333. doi: 10.4103/ijmr.IJMR_1304_17. - DOI - PMC - PubMed
    1. Lalloo D.G., Shingadia D., Bell D.J., Beeching N.J., Whitty C.J.M., Chiodini P.L., PHE Advisory Committee on Malaria Prevention in UK Travellers UK malaria treatment guidelines 2016. J. Infect. 2016;72:635–649. doi: 10.1016/j.jinf.2016.02.001. - DOI - PMC - PubMed