Tess Puopolo1,2, Chang Liu1, Hang Ma1,2, Navindra P Seeram1,2. 1. Bioactive Botanical Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island, USA. 2. George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, Rhode Island, USA.
Abstract
Introduction: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are two cholinergic enzymes catalyzing the reaction of cleaving acetylcholine into acetate and choline at the neuromuscular junction. Abnormal hyperactivity of AChE and BChE can lead to cholinergic deficiency, which is associated with several neurological disorders including cognitive decline and memory impairments. Preclinical studies support that some cannabinoids including cannabidiol (CBD) and tetrahydrocannabinol (THC) may exert pharmacological effects on the cholinergic system, but it remains unclear whether cannabinoids can inhibit AChE and BChE activities. Herein, we aimed to evaluate the inhibitory effects of a panel of cannabinoids including CBD, Δ8-THC, cannabigerol (CBG), cannabigerolic acid (CBGA), cannabicitran (CBT), cannabidivarin (CBDV), cannabichromene (CBC), and cannabinol (CBN) on AChE and BChE activities. Methods: The inhibitory effects of cannabinoids on the activities of AChE and BChE enzymes were evaluated with the Ellman method using acetyl- and butyryl-thiocholines as substrates. The inhibition mechanism of cannabinoids on AChE and BChE was studied with enzyme kinetic assays including the Lineweaver-Burk and Michaelis-Menten analyses. In addition, computational-based molecular docking experiments were performed to explore the interactions between the cannabinoids and the enzyme proteins. Results: Cannabinoids including CBD, Δ8-THC, CBG, CBGA, CBT, CBDV, CBC, and CBN (at 200 µM) inhibited the activities of AChE and BChE by 70.8, 83.7, 92.9, 76.7, 66.0, 79.3, 13.7, and 30.5%, and by 86.8, 80.8, 93.2, 87.1, 77.0, 78.5, 27.9, and 22.0%, respectively. The inhibitory effects of these cannabinoids (with IC50 values ranging from 85.2 to >200 µM for AChE and 107.1 to >200 µM for BChE) were less potent as compared to the positive control galantamine (IC50 1.21 and 6.86 µM for AChE and BChE, respectively). In addition, CBD, as a representative cannabinoid, displayed a competitive type of inhibition on both AChE and BChE. Data from the molecular docking studies suggested that cannabinoids interacted with several amino acid residues on the enzyme proteins, which supported their overall inhibitory effects on AChE and BChE. Conclusion: Cannabinoids showed moderate inhibitory effects on the activities of AChE and BChE enzymes, which may contribute to their modulatory effects on the cholinergic system. Further studies using cell-based and in vivo models are warranted to evaluate whether cannabinoids' neuroprotective effects are associated with their anti-cholinesterase activities.
Introduction: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are two cholinergic enzymes catalyzing the reaction of cleaving acetylcholine into acetate and choline at the neuromuscular junction. Abnormal hyperactivity of AChE and BChE can lead to cholinergic deficiency, which is associated with several neurological disorders including cognitive decline and memory impairments. Preclinical studies support that some cannabinoids including cannabidiol (CBD) and tetrahydrocannabinol (THC) may exert pharmacological effects on the cholinergic system, but it remains unclear whether cannabinoids can inhibit AChE and BChE activities. Herein, we aimed to evaluate the inhibitory effects of a panel of cannabinoids including CBD, Δ8-THC, cannabigerol (CBG), cannabigerolic acid (CBGA), cannabicitran (CBT), cannabidivarin (CBDV), cannabichromene (CBC), and cannabinol (CBN) on AChE and BChE activities. Methods: The inhibitory effects of cannabinoids on the activities of AChE and BChE enzymes were evaluated with the Ellman method using acetyl- and butyryl-thiocholines as substrates. The inhibition mechanism of cannabinoids on AChE and BChE was studied with enzyme kinetic assays including the Lineweaver-Burk and Michaelis-Menten analyses. In addition, computational-based molecular docking experiments were performed to explore the interactions between the cannabinoids and the enzyme proteins. Results: Cannabinoids including CBD, Δ8-THC, CBG, CBGA, CBT, CBDV, CBC, and CBN (at 200 µM) inhibited the activities of AChE and BChE by 70.8, 83.7, 92.9, 76.7, 66.0, 79.3, 13.7, and 30.5%, and by 86.8, 80.8, 93.2, 87.1, 77.0, 78.5, 27.9, and 22.0%, respectively. The inhibitory effects of these cannabinoids (with IC50 values ranging from 85.2 to >200 µM for AChE and 107.1 to >200 µM for BChE) were less potent as compared to the positive control galantamine (IC50 1.21 and 6.86 µM for AChE and BChE, respectively). In addition, CBD, as a representative cannabinoid, displayed a competitive type of inhibition on both AChE and BChE. Data from the molecular docking studies suggested that cannabinoids interacted with several amino acid residues on the enzyme proteins, which supported their overall inhibitory effects on AChE and BChE. Conclusion: Cannabinoids showed moderate inhibitory effects on the activities of AChE and BChE enzymes, which may contribute to their modulatory effects on the cholinergic system. Further studies using cell-based and in vivo models are warranted to evaluate whether cannabinoids' neuroprotective effects are associated with their anti-cholinesterase activities.
Authors: Weixi Liu; Hang Ma; Nicholas A DaSilva; Kenneth N Rose; Shelby L Johnson; Lu Zhang; Chunpeng Wan; Joel A Dain; Navindra P Seeram Journal: Neurochem Int Date: 2016-09-29 Impact factor: 3.921
Authors: Thaiane Coelho Dos Santos; Thaís Mota Gomes; Bruno Araújo Serra Pinto; Adriana Leandro Camara; Antonio Marcus de Andrade Paes Journal: Front Pharmacol Date: 2018-10-18 Impact factor: 5.988
Authors: Kenneth N Rose; Benjamin J Barlock; Nicholas A DaSilva; Shelby L Johnson; Chang Liu; Hang Ma; Robert Nelson; Fatemeh Akhlaghi; Navindra P Seeram Journal: Nutr Neurosci Date: 2019-10-04 Impact factor: 4.994