Pharmacology, Biochemistry and Behavior 104(2013)138-143 Contents lists available at SciVerse Science Direct Pharmacology Biochemistry and behavior ELSEVIER journalhomepagewww.elsevier.com/locate/pharmbiochembeh Bis(9)-(-)-nor-meptazinol as a novel dual-binding AChEl potently ameliorates scopolamine-induced cognitive deficits in mice Ting Liu a, d, Zheng Xia a, Wei-Wei Zhang 1, Jian-rong Xu, Xin-Xing Ge a, Juan Li a, Yongyao Cui a, Zhui- Bai Qiu, Jun Xu, Qiong Xie*, Hao Wang…*, Hong-Zhuan Chen己常米 ent of pharmacology, Institute of Medical Sciences, Shanghai jiao Tong University School of medicine, PR China ent of Medicinal Chemistry, School of pharmacy, Fudan University, PR China Center for Drug Discovery, School of pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, PR China ent of pharmacy, Ren Hospital, Shanghai Jiao Tong University School of Medicine, PR China ARTICLE INFO A BSTRACT lzheimer's disease(AD)is a multifaceted neurodegenerative disorder which is characterized by the progres- brary 2012 ive deterioration of cognition and the emergence of behavioral and psychological symptoms in aging in revised form 18 November 2012 Accepted 22 November 2012 patients. Given that the clinical effectiveness of acetylcholinesterase inhibitors(AChEls)has still been Available online 19 December 2012 questioned due to dubious disease-modifying effects, the multi-target directed ligand(MTDL) design has become an emerging strategy for developing new drugs for AD treatment. Bis(9)-(-)-nor-meptazinol (Bis-Mep)was firstly reported by us as a novel MTDL for both potent cholinesterase and amyloid-B aggrega- tion inhibition. In this study, we further explored its AChE inhibition kinetic features and cognitive ameliora tion. Bis-Mep was found to be a mixed-type inhibitor on electric eel AChE by enzyme kinetic study. Molecular ual-binding achE inhibitor ocking revealed that two"water bridges"located at the two wings of Bis-Mep stabilized its interaction with Cognitive meliora both catalytic and peripheral anionic sites of AChE. Furthermore, subcutaneous administration of Bis-Mep(10. 100 or 1000 ng/kg)significantly reversed the scopolamine-induced memory deficits in a typical bell-shaped onse manner. The maximal cognitive amelioration of Bis-Mep was achieved at 100 ng/kg, comparable with the effect of a reference drug Huperzine A at 1 mg/kg and also the relevant AChE inhibition in brain. These findings suggested that Bis-Mep might be a promising dual-binding AChE inhibitor for potential AD therapeutics. o 2012 Elsevier Inc. All rights reserved. 1 Introduction contributes to cognition decline. Therefore, acetylcholinesterase inhibi- tors(AChEls). which inhibit catalytic anionic site(CAS)and increase Alzheimer's disease(AD)is a multifaceted neurodegenerative dis- the availability of acetylcholine(Ach) in synaptic cleft, have been wide- order which is characterized by the progressive deterioration of coms Gauthier, 2010). AChEIs including donepezil galamantine, rivastigmine nition and the emergence of behavioral and psychological sympt in aging patients. Although senile plaques and neurofibrillary tangles and tacrine have been approved by FDa for AD patients to ameliorate are generally accepted as the hallmarks of AD, cholinergic deficiency their cognitive deficits. However, the clinical effectiveness of AchEls has still been questioned due to dubious disease-modifying effects (Small, 2005: Terry and Buccafusco, 2003). Given the complex multifactorial etiology of AD, it is generally AD,Alzheimer's disease:BBB, the blood brain barrier: Bis-Mep. Bis(9)-(-)-nor- accepted that a multi-target therapeutic approach is necessary eptazinol; CAS, catalytic anionic site of AChE; PAS, peripheral anionic site of AChE:( Cavalli et aL, 2008: Lee et al, 2010). Drug discovery for AD, following multi-target directed ligand(MTDL) design, gradually focused on Corresponding authors at: Departmentof Pharmacology, Institute of Medical Sciences, modulating multiple targets implicated in AD pathogenesis. Notably, oTon University School of Medicine, 280 South Chongqing Road, Shanghai, the peripheral anionic site of AChE which is located at the active Medicinal Chemistry, School of Pharmacy, Fudan University, $26 Zhangheng road, Shang center gorge entry, has been shown to be associated with amyloid-B 201203, PR China. tel:+862151980122;fax+862151980122 (AB)aggregation(Munoz-Torrero, 2008). Thus, dual-binding AChEls Correspondence to: Prof Hongzhuan Chen, Department of Pharmacology, Institute which can simultaneously bind to the CAs and PAS of Ache, have going Road, Shanghai.200025, PR China.Tel:+862164398859;fax+862164392916. been proposed to be an advanced strategy to ameliorate symptoms -mailaddresses:xiejoanxq@gmail.com(Q,Xie),angela_wanghaoehotm and disease progression of AD(Bourne et al, 2003). H.Wang),hongzhuan_chen@hotmail.com(h.-zChen). Recently, some dimeric AChEls in which two moieties linked Contributed equally to this work by a suitable length chain can interact with the CAs and the pas 0091-3057/S- see front matter a 2012 Elsevier Inc. All rights reserved htp:/ dxdolorg/10.1016/pb2012.11009Bis(9)-(−)-nor-meptazinol as a novel dual-binding AChEI potently ameliorates scopolamine-induced cognitive deficits in mice Ting Liu a,d,1 , Zheng Xia a,1 , Wei-Wei Zhang a,1 , Jian-rong Xu a , Xin-Xing Ge a , Juan Li a , Yongyao Cui a , Zhui-Bai Qiu b , Jun Xu c , Qiong Xie b, ⁎, Hao Wang a, ⁎, Hong-Zhuan Chen a, ⁎, ⁎⁎ a Department of Pharmacology, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, PR China b Department of Medicinal Chemistry, School of Pharmacy, Fudan University, PR China c Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, PR China d Department of Pharmacy, Renji Hospital, Shanghai JiaoTong University School of Medicine, PR China article info abstract Article history: Received 10 February 2012 Received in revised form 18 November 2012 Accepted 22 November 2012 Available online 19 December 2012 Keywords: Bis-Mep MTDL Dual-binding AChE inhibitor Cognitive amelioration Alzheimer's disease (AD) is a multifaceted neurodegenerative disorder which is characterized by the progres￾sive deterioration of cognition and the emergence of behavioral and psychological symptoms in aging patients. Given that the clinical effectiveness of acetylcholinesterase inhibitors (AChEIs) has still been questioned due to dubious disease-modifying effects, the multi-target directed ligand (MTDL) design has become an emerging strategy for developing new drugs for AD treatment. Bis(9)-(−)-nor-meptazinol (Bis-Mep) was firstly reported by us as a novel MTDL for both potent cholinesterase and amyloid-β aggrega￾tion inhibition. In this study, we further explored its AChE inhibition kinetic features and cognitive ameliora￾tion. Bis-Mep was found to be a mixed-type inhibitor on electric eel AChE by enzyme kinetic study. Molecular docking revealed that two “water bridges” located at the two wings of Bis-Mep stabilized its interaction with both catalytic and peripheral anionic sites of AChE. Furthermore, subcutaneous administration of Bis-Mep (10, 100 or 1000 ng/kg) significantly reversed the scopolamine-induced memory deficits in a typical bell-shaped dose–response manner. The maximal cognitive amelioration of Bis-Mep was achieved at 100 ng/kg, comparable with the effect of a reference drug Huperzine A at 1 mg/kg and also the relevant AChE inhibition in brain. These findings suggested that Bis-Mep might be a promising dual-binding AChE inhibitor for potential AD therapeutics. © 2012 Elsevier Inc. All rights reserved. 1. Introduction Alzheimer's disease (AD) is a multifaceted neurodegenerative dis￾order which is characterized by the progressive deterioration of cog￾nition and the emergence of behavioral and psychological symptoms in aging patients. Although senile plaques and neurofibrillary tangles are generally accepted as the hallmarks of AD, cholinergic deficiency contributes to cognition decline. Therefore, acetylcholinesterase inhibi￾tors (AChEIs), which inhibit catalytic anionic site (CAS) and increase the availability of acetylcholine (ACh) in synaptic cleft, have been wide￾ly used for the treatment of mild to moderate AD (Massoud and Gauthier, 2010). AChEIs including donepezil, galamantine, rivastigmine and tacrine have been approved by FDA for AD patients to ameliorate their cognitive deficits. However, the clinical effectiveness of AChEIs has still been questioned due to dubious disease-modifying effects (Small, 2005; Terry and Buccafusco, 2003). Given the complex multifactorial etiology of AD, it is generally accepted that a multi-target therapeutic approach is necessary (Cavalli et al., 2008; Lee et al., 2010). Drug discovery for AD, following multi-target directed ligand (MTDL) design, gradually focused on modulating multiple targets implicated in AD pathogenesis. Notably, the peripheral anionic site of AChE which is located at the active center gorge entry, has been shown to be associated with amyloid-β (Aβ) aggregation (Muñoz-Torrero, 2008). Thus, dual-binding AChEIs, which can simultaneously bind to the CAS and PAS of AChE, have been proposed to be an advanced strategy to ameliorate symptoms and disease progression of AD (Bourne et al., 2003). Recently, some dimeric AChEIs in which two moieties linked by a suitable length chain can interact with the CAS and the PAS Pharmacology, Biochemistry and Behavior 104 (2013) 138–143 Abbreviations: AChE, acetylcholinesterase; AChEIs, acetylcholinesterase inhibitors; AD, Alzheimer's disease; BBB, the blood brain barrier; Bis-Mep, Bis(9)-(−)-nor￾meptazinol; CAS, catalytic anionic site of AChE; PAS, peripheral anionic site of AChE; Scop, scopolamine; Hup A, Huperzine A. ⁎ Corresponding authors at: Department of Pharmacology, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China. Tel.: +86 21 63846590; fax: +86 21 64392916; Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, PR China. Tel.: +86 21 51980122; fax: +86 21 51980122. ⁎⁎ Correspondence to: Prof. Hongzhuan Chen, Department of Pharmacology, Institute of Medical Sciences, Shanghai JiaoTong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, PR China. Tel.: +86 21 64398859; fax: +86 21 64392916. E-mail addresses: xiejoanxq@gmail.com (Q. Xie), angela_wanghao@hotmail.com (H. Wang), hongzhuan_chen@hotmail.com (H.-Z. Chen). 1 Contributed equally to this work. 0091-3057/$ – see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pbb.2012.11.009 Contents lists available at SciVerse ScienceDirect Pharmacology, Biochemistry and Behavior journal homepage: www.elsevier.com/locate/pharmbiochembeh