Investigation of synergistic mechanism and identification of interaction site of aldose reductase with the combination of gigantol and syringic acid for prevention of diabetic cataract

BMC Complementary and Alternative Medicine

Research Article

C-Y. Oliver Chen¹  Xue Li²  Dan Chen²  Yan Long²  Yanqun Yi²  Hua Fang²  Jie Wu²  Xinxin Gao²  Xiaoyong Wei³ 

[1] Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, 02111, Boston, MA, USA;Department of Histology and Embryology, Guangzhou University of Chinese Medicine, 510006, Guangzhou, China;Department of Histology and Embryology, Guangzhou University of Chinese Medicine, 510006, Guangzhou, China;Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, 02111, Boston, MA, USA;

关键词: Synergism;    Diabetic cataract;    Site-directed mutagenesis;    Gigantol;    Syringic acid;    Aldose reductase;   

DOI  :  10.1186/s12906-016-1251-5

 received in 2015-08-14, accepted in 2016-07-29,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundGigantol and syringic acid (SA) have been shown to synergistically prevent formation of diabetic cataract (DC). However, the exact mechanism of this effect is unknown. Here, we investigate the effect of these compounds on the activity of aldose reductase (AR) and cataract formation.MethodsWe examined the synergistic anti-cataract efficacy of gigantol and SA in the high glucose- and streptozotocin -induced DC rat model; synergism was evaluated using Jin’s formula. We investigated possible mechanisms of action by measuring AR expression and activity and levels of sorbitol using enzyme kinetics, Western blot, and RT-PCR. Finally, we examined binding interaction between AR and both compounds using a combination of site-directed mutagenesis, recombinant expression of wild-type and mutant proteins, and enzyme kinetics.ResultsCombination treatment of gigantol and SA synergistically protected both HLECs(human lens epithelial cells) grown in vitro and DC formation in STZ-induced rats in vivo. Synergism was attributed to inhibition of AR activity, downregulation of AR expression via impaired transcription, and decreased sorbitol levels. Enzyme kinetics studies showed that the activity of an AR Asn160Ala mutant protein was significantly decreased compared to wild-type AR, confirming that Asn160 is a key residue for interaction between AR and both compounds.ConclusionCombined administration of gigantol and SA synergize to enhance anti-cataract efficacy. The synergistic effect is mainly attributed to disruption of the polyol pathway and inhibition of AR activity.

【 授权许可】

CC BY   
© The Author(s). 2016