Masahiro Watanabe1, Takao Toyomura1, Ryo Ikegami1, Yui Suwaki1, Minami Sada1, Hidenori Wake2, Takashi Nishinaka2, Omer Faruk Hatipoglu2, Hideo Takahashi2, Masahiro Nishibori3, Shuji Mori4. 1. Department of Pharmacology, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, 703-8516, Okayama, Japan. 2. Department of Pharmacology, Faculty of Medicine, Kindai University, 589-8511, Osaka-Sayama, Japan. 3. Department of Pharmacology, Dentistry, and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 700-8558, Okayama, Japan. 4. Department of Pharmacology, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, 703-8516, Okayama, Japan. morimori@shujitsu.ac.jp.
Abstract
BACKGROUND: Methylglyoxal (MGO) is a known toxic byproduct of glycolysis, with MGO-induced cytotoxicity believed to contribute to the pathogenesis of several diseases. Glyoxalase I (GLO1) is a key enzyme for eliminating MGO in mammalian cells, therefore, compounds affecting GLO1 activity are potential therapeutic agents for MGO-induced disorders. Previously, we found nordihydroguaiaretic acid (NDGA) as a potent GLO1 inhibitor. METHODS: The inhibitory characteristics of NDGA were determined spectrophotometrically with recombinant GLO1. NDGA-induced growth-inhibition and accumulation of MGO-derived advanced glycation end products (AGEs) were examined in EA.hy926 cells. RESULTS: NDGA showed significant inhibition of GLO1 enzymatic activity in a dose-dependent manner. Its Ki value was estimated to be 146-fold lower than that of myricetin, a known GLO1 inhibitor. The co-addition of MGO with NDGA to the cells resulted in significant growth inhibition, suggesting that MGO accumulation, sufficient to affect cell growth, was caused by NDGA inhibiting GLO1. These findings were supported by the observations that the addition of aminoguanidine, a typical MGO scavenger, significantly reversed cell-growth inhibition by co-addition of MGO with NDGA, and that an increase in intracellular MGO-derived AGEs was observed during incubation with the co-addition of MGO with NDGA. CONCLUSION: NDGA was found to be a novel and potent inhibitor of GLO1. The co-addition of NDGA with MGO to the cells resulted in increased intracellular MGO accumulation followed by enhanced cell-growth inhibition.
BACKGROUND: Methylglyoxal (MGO) is a known toxic byproduct of glycolysis, with MGO-induced cytotoxicity believed to contribute to the pathogenesis of several diseases. Glyoxalase I (GLO1) is a key enzyme for eliminating MGO in mammalian cells, therefore, compounds affecting GLO1 activity are potential therapeutic agents for MGO-induced disorders. Previously, we found nordihydroguaiaretic acid (NDGA) as a potent GLO1 inhibitor. METHODS: The inhibitory characteristics of NDGA were determined spectrophotometrically with recombinant GLO1. NDGA-induced growth-inhibition and accumulation of MGO-derived advanced glycation end products (AGEs) were examined in EA.hy926 cells. RESULTS: NDGA showed significant inhibition of GLO1 enzymatic activity in a dose-dependent manner. Its Ki value was estimated to be 146-fold lower than that of myricetin, a known GLO1 inhibitor. The co-addition of MGO with NDGA to the cells resulted in significant growth inhibition, suggesting that MGO accumulation, sufficient to affect cell growth, was caused by NDGA inhibiting GLO1. These findings were supported by the observations that the addition of aminoguanidine, a typical MGO scavenger, significantly reversed cell-growth inhibition by co-addition of MGO with NDGA, and that an increase in intracellular MGO-derived AGEs was observed during incubation with the co-addition of MGO with NDGA. CONCLUSION: NDGA was found to be a novel and potent inhibitor of GLO1. The co-addition of NDGA with MGO to the cells resulted in increased intracellular MGO accumulation followed by enhanced cell-growth inhibition.
Authors: M Neeper; A M Schmidt; J Brett; S D Yan; F Wang; Y C Pan; K Elliston; D Stern; A Shaw Journal: J Biol Chem Date: 1992-07-25 Impact factor: 5.157