Flavonoids: Efficient protectors of glucose-6-phosphate dehydrogenase from ultrasonic cavitation-induced inactivation

• Published in: Applied biochemistry and microbiology 2007-04, Vol.43 (2), p.139-149
• Main Authors: Karasyova, E. I., Kurchenko, V. P., Metelitza, D. I.
• Format: Article
• Language: English
• Subjects: Cavitation; Dehydrogenase; Flavonoids; Free radicals; High temperature; Inactivation
• ISSN: 0003-6838; 1608-3024
• DOI: 10.1134/S0003683807020020

Seven structurally diverse flavonoids have been shown to decrease glucose-6-phosphate dehydrogenase (G6PDH) inactivation in 0.1 M phosphate buffer (pH 7.4), induced by exposure to a high temperature (44°C), or by a low-frequency ultrasound (27 kHz, 60 Wt/cm^sup 2^). The activity of the compounds was assessed by their ability to change effective first-order rate constants characterizing the total (thermal and ultrasonic), thermal, and ultrasonic inactivation of 2.5 nM G6PDH (k ^sub in^, k*^sub in^, and k ^sub in^(us), respectively). The value dependences of these constants on flavonoid concentrations (0.01-50 μM) were obtained. Rank order of potency exhibited by the compounds in protecting G6PDH appeared as follows: hesperidin > morin > silibin > naringin = quercetin > kampferol astragalin. The data obtained confirm the crucial role of free radicals formed in the field of ultrasonic cavitation (HO^sup ·^ and O ^sub 2^ ^sup ·-^ in G6PDH inactivation in solutions.[PUBLICATION ABSTRACT]