Alzheimer’s Disease (AD) shows cognitive dysfunction as core symptoms and Behavioral and Psychological Symptoms of Dementia (BPSD). Since acetylcholine nerve system derived from septum is collapsed in the AD patients...Alzheimer’s Disease (AD) shows cognitive dysfunction as core symptoms and Behavioral and Psychological Symptoms of Dementia (BPSD). Since acetylcholine nerve system derived from septum is collapsed in the AD patients, we have used Olfactory Bulbectomized (OBX) mice whose cholinergic system is largely impaired in the septum. Recently, Yokukansankachimpihange (YKH), a traditional Japanese Kampo medicine has used for BPSD in addition to improve cognitive dysfunction in AD patients. However the essential components for cognition and BPSD improvement and their mechanism are largely unknown. In present study, we found that Atractylenolide III (Aen-III), one of the components of YKH, improved cognitive deficits and depression in the OBX mice. OBX mice were orally administered with Aen-III (1.0 and 3.0 mg/kg) and YKH extracts daily for 18 days. Like YKH extracts, the Aen-III treatments ameliorated cognitive deficits and depression-like behavior observed in OBX mice. Importantly, Aen-III administration significantly restored the decreases in Ca2+/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation and phosphorylation of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) and cyclic AMP response element binding protein (CREB). The restoration of CaMKII and CaMKIV signaling is closely related to the increased BDNF levels. Furthermore, ATP reduction in OBX mice was rescued by Aen-III (3.0 mg/kg) and YKH (1000 mg/kg) treatment. In summary, Aen-III as a component of YKH ameliorates cognitive dysfunctions and depression via restoring CaMKII and CaMKIV signaling.展开更多
Rivastigmine, a dual acetylcholinesterase and butyrylcholinesterase inhibitor, is used for symptomatic treatment of patients with mild to moderately severe dementia in Alzheimer’s disease (AD) patients. In the presen...Rivastigmine, a dual acetylcholinesterase and butyrylcholinesterase inhibitor, is used for symptomatic treatment of patients with mild to moderately severe dementia in Alzheimer’s disease (AD) patients. In the present study, we found that 5-HT1A receptor (5-HT1AR) is downregulated, whereas 5-HT2A receptor (5-HT2AR) is upregulated in the hippocampal dentate gyrus (DG) and CA1 region by olfactory bulbectomy (OBX) in mice. Furthermore, chronic treatment with rivastigmine (1.0 mg/kg) for 2 weeks starting 2 weeks after OBX operation restored the decreased 5-HT1AR and the increased 5-HT2AR levels. To determine whether cholinergic receptor stimulation by rivastigmine is involved in the rivastigmine-induced regulation of 5-HTR levels, we treated the mice with mecamylamine (2.5 mg/kg), or atropine (5.0 mg/kg) with rivastigmine (1.0 mg/kg) once a day for 2 weeks. Notably, the rivastigmine-induced 5-HT1AR upregulation was eliminated by mecamylamine but not by atropine treatments. On the other hand, the restored 5-HT2AR level by rivastigmine was not affected by either mecamylamine or atropine. Treatment with 8-OH-DPAT, a selective 5-HT1AR agonist improved the decreased 5-HT1AR and the increased 5-HT2AR levels in OBX mice. On the other hand, treatment with TCB-2, a potent 5-HT2AR agonist had no effects on the 5-HT1AR and 5-HT2AR dysregulation in OBX mice. Taken together, nicotinic acetylcholine receptor (nAChR) stimulation mediates rivastigmine-induced upregulation of 5-HT1AR. Therefore, we speculate that the increased ACh levels by rivastigmine can stimulate nAChR located on serotonergic nerve terminals and stimulate 5-HT1AR by the enhanced 5-HT release in the hippocampus. The 5-HT1AR stimulation likely mediates the improvement of 5-HT1AR levels as auto-receptor in OBX hippocampus.展开更多
文摘Alzheimer’s Disease (AD) shows cognitive dysfunction as core symptoms and Behavioral and Psychological Symptoms of Dementia (BPSD). Since acetylcholine nerve system derived from septum is collapsed in the AD patients, we have used Olfactory Bulbectomized (OBX) mice whose cholinergic system is largely impaired in the septum. Recently, Yokukansankachimpihange (YKH), a traditional Japanese Kampo medicine has used for BPSD in addition to improve cognitive dysfunction in AD patients. However the essential components for cognition and BPSD improvement and their mechanism are largely unknown. In present study, we found that Atractylenolide III (Aen-III), one of the components of YKH, improved cognitive deficits and depression in the OBX mice. OBX mice were orally administered with Aen-III (1.0 and 3.0 mg/kg) and YKH extracts daily for 18 days. Like YKH extracts, the Aen-III treatments ameliorated cognitive deficits and depression-like behavior observed in OBX mice. Importantly, Aen-III administration significantly restored the decreases in Ca2+/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation and phosphorylation of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) and cyclic AMP response element binding protein (CREB). The restoration of CaMKII and CaMKIV signaling is closely related to the increased BDNF levels. Furthermore, ATP reduction in OBX mice was rescued by Aen-III (3.0 mg/kg) and YKH (1000 mg/kg) treatment. In summary, Aen-III as a component of YKH ameliorates cognitive dysfunctions and depression via restoring CaMKII and CaMKIV signaling.
文摘Rivastigmine, a dual acetylcholinesterase and butyrylcholinesterase inhibitor, is used for symptomatic treatment of patients with mild to moderately severe dementia in Alzheimer’s disease (AD) patients. In the present study, we found that 5-HT1A receptor (5-HT1AR) is downregulated, whereas 5-HT2A receptor (5-HT2AR) is upregulated in the hippocampal dentate gyrus (DG) and CA1 region by olfactory bulbectomy (OBX) in mice. Furthermore, chronic treatment with rivastigmine (1.0 mg/kg) for 2 weeks starting 2 weeks after OBX operation restored the decreased 5-HT1AR and the increased 5-HT2AR levels. To determine whether cholinergic receptor stimulation by rivastigmine is involved in the rivastigmine-induced regulation of 5-HTR levels, we treated the mice with mecamylamine (2.5 mg/kg), or atropine (5.0 mg/kg) with rivastigmine (1.0 mg/kg) once a day for 2 weeks. Notably, the rivastigmine-induced 5-HT1AR upregulation was eliminated by mecamylamine but not by atropine treatments. On the other hand, the restored 5-HT2AR level by rivastigmine was not affected by either mecamylamine or atropine. Treatment with 8-OH-DPAT, a selective 5-HT1AR agonist improved the decreased 5-HT1AR and the increased 5-HT2AR levels in OBX mice. On the other hand, treatment with TCB-2, a potent 5-HT2AR agonist had no effects on the 5-HT1AR and 5-HT2AR dysregulation in OBX mice. Taken together, nicotinic acetylcholine receptor (nAChR) stimulation mediates rivastigmine-induced upregulation of 5-HT1AR. Therefore, we speculate that the increased ACh levels by rivastigmine can stimulate nAChR located on serotonergic nerve terminals and stimulate 5-HT1AR by the enhanced 5-HT release in the hippocampus. The 5-HT1AR stimulation likely mediates the improvement of 5-HT1AR levels as auto-receptor in OBX hippocampus.