Das Debashree, Sen Souvik, Sen Kamalika
Department of Chemistry, University of Calcutta, 92, APC Road, Kolkata 700009, India.
KPC Medical College & Hospital, 1F, Raja Subodh Chandra Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 May 5;232:118167. doi: 10.1016/j.saa.2020.118167. Epub 2020 Feb 19.
Administration of low doses of nitrates over prolonged periods in patients suffering from coronary heart disease may lead to chronic methemoglobinemia, a disease caused by oxidation of hemoglobin. Previous reports have shown that natural products like curcumin, vitamin E, vitamin C, resveratrol, etc., are capable of inhibition of nitrite induced oxidation of hemoglobin. Hence in this study we aimed to investigate the preventive role of antioxidants present in our diet, like caffeine and catechin hydrate which are commonly found in coffee and tea towards methemoglobin (met-Hb) formation. Our study revealed that when the hemolysate was pre-incubated with equimolar concentration of caffeine and its metabolite with respect to nitrite, the rate of the nitrite induced oxidation of HbA decreased from (7.33 ± 0.54) × 10 min to (7.09 ± 1.05) × 10 min and (2.98 ± 0.06) × 10 min respectively. Hence it was evident that the metabolite of caffeine, 1-methyluric acid, exhibited better efficiency at physiological concentration than its precursor. On the contrary, only 4 mM catechin hydrate could enhance the rate of methemoglobin formation even in absence of nitrite and the rate of the reaction was (6.088 ± 0.31) × 10 min which is comparable with that of 400 μM nitrite.
在冠心病患者中长期给予低剂量硝酸盐可能会导致慢性高铁血红蛋白血症，这是一种由血红蛋白氧化引起的疾病。先前的报告表明，姜黄素、维生素E、维生素C、白藜芦醇等天然产物能够抑制亚硝酸盐诱导的血红蛋白氧化。因此，在本研究中，我们旨在研究饮食中常见的抗氧化剂，如咖啡和茶中常见的咖啡因和儿茶素水合物对高铁血红蛋白（met-Hb）形成的预防作用。我们的研究表明，当溶血产物与亚硝酸盐等摩尔浓度的咖啡因及其代谢物预孵育时，亚硝酸盐诱导的HbA氧化速率分别从（7.33±0.54）×10⁻⁴min⁻¹降至（7.09±1.05）×10⁻⁴min⁻¹和（2.98±0.06）×10⁻⁴min⁻¹。因此，很明显，咖啡因的代谢物1-甲基尿酸在生理浓度下比其前体表现出更好的效果。相反，即使在没有亚硝酸盐的情况下，仅4mM儿茶素水合物就能提高高铁血红蛋白的形成速率，反应速率为（6.088±0.31）×10⁻⁴min⁻¹，与400μM亚硝酸盐的反应速率相当。
