Samandar Farzaneh, Mohsenpour Aida, Rastin Farangis, Doustmohammadi-Salmani Sara, Saberi Mohammad Reza, Chamani Jamshidkhan
Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Apr 5;330:125638. doi: 10.1016/j.saa.2024.125638. Epub 2024 Dec 20.
In this work, we sought to apprehend quercetin binding affinity and its interaction behavior in complex with human serum albumin (HSA) and calf thymus DNA (ctDNA) through multi spectroscopy and molecular dynamics and also evaluated its effects on colorectal cancer. The binding constants of ctDNA-quercetin and HSA-quercetin complexes at 298 K, which were calculated to be (2.67 ± 0.04) × 10 M and (4.77 ± 0.05) × 10 M respectively, denoted the strong binding of quercetin with ctDNA and HSA. The K and K values decrease with increasing temperature, indicating that the quenching of HSA and ctDNA in the presence of quercetin is caused by the combined dynamic and static effects. The obtained thermodynamic parameters for the ctDNA-quercetin interaction represented the existence of electrostatic forces (ΔH < 0 and ΔS > 0), and the thermodynamic parameters of HSA-quercetin complex disclose the dominance of hydrogen bonds and van der Waals interactions (ΔH < 0 and ΔS < 0). Moreover, the interactions were exothermic, as evidenced by the negative ΔH value for both interactions. According to molecular docking and MD simulation data, quercetin was capable of placing into the site 1 of HSA and forming stable interaction plus this ligand tended to unwind DNA's strands as an intercalator ligand, which was confirmed by experimental results. The fluorescence competition studies between the two intercalator probes of ethidium bromide (EB) and acridine orange (AO), as well as the effect of ionic strength, proposed the strong tendency of quercetin to exist between the two strands of ctDNA as a sign of its intercalative property. Consequently, quercetin can be assumed as an efficient intercalator ligand carried by HSA with an anticancer property. We also conducted cell viability experiments on HT-29 and SW620 cell lines to validate the anticancer ability of quercetin, and observed its decreasing impact on the cell viability of these two cell lines. Additionally, the outcomes of Real-time qPCR proved its capability to reduce the CXCR4 expression and increase the NKD2 expression in Wnt signaling pathway. Therefore, these facts confirm the inhibiting ability of quercetin towards colorectal cancer growth via the prevention of Wnt pathway and approve its functionality as a potential anticancer agent for this cancer.
在本研究中，我们试图通过多光谱和分子动力学来了解槲皮素与人血清白蛋白（HSA）和小牛胸腺DNA（ctDNA）结合的亲和力及其相互作用行为，并评估其对结直肠癌的影响。ctDNA - 槲皮素和HSA - 槲皮素复合物在298K时的结合常数分别计算为(2.67 ± 0.04) × 10⁶ M和(4.77 ± 0.05) × 10⁶ M，这表明槲皮素与ctDNA和HSA有很强的结合。Ksv和Kq值随温度升高而降低，表明在槲皮素存在下HSA和ctDNA的猝灭是由动态和静态效应共同引起的。ctDNA - 槲皮素相互作用获得的热力学参数表明存在静电力（ΔH < 0且ΔS > 0），而HSA - 槲皮素复合物的热力学参数揭示了氢键和范德华相互作用占主导（ΔH < 0且ΔS < 0）。此外，两种相互作用均为放热反应，这由两种相互作用的负ΔH值证明。根据分子对接和分子动力学模拟数据，槲皮素能够进入HSA的位点1并形成稳定的相互作用，并且这种配体倾向于作为嵌入配体解开DNA链，这已通过实验结果得到证实。溴化乙锭（EB）和吖啶橙（AO）这两种嵌入探针之间的荧光竞争研究以及离子强度的影响表明，槲皮素强烈倾向于存在于ctDNA的两条链之间，这是其嵌入性质的一个标志。因此，槲皮素可以被认为是一种由HSA携带的具有抗癌特性的有效嵌入配体。我们还对HT - 29和SW620细胞系进行了细胞活力实验，以验证槲皮素的抗癌能力，并观察到其对这两种细胞系细胞活力的降低作用。此外，实时定量PCR的结果证明了其在Wnt信号通路中降低CXCR4表达和增加NKD2表达的能力。因此，这些事实证实了槲皮素通过预防Wnt通路对结直肠癌生长的抑制能力，并认可其作为这种癌症潜在抗癌剂的功能。
