Preparation of huperzine A nasal in situ gel and evaluation of its brain targeting following intranasal administration

Tao T, Zhao Y, Yue P, Dong WX, Chen QH.

Yao Xue Xue Bao. 2006 Nov;41(11):1104-10.

Shanghai Institute of Pharmaceutical Industry, Shanghai 200040, China. taotaosipi@hotmail.com

AIM: The feasibility of intranasal brain targeting drug delivery system via the olfactory pathway from nose to brain was explored. METHODS: Using gellan gum, a cation-sensitive gel forming excipient, huperzine A (Hup A) nasal in situ gel was prepared by pH gradient precipitation method. The pharmacokinetics of Hup A in blood and cerebrospinal fluid (CSF) after intranasal, intravenous and intragastric adminstration to rats was studied using cisternal cannulation for serial CSF sampling and femoral artery cannulation for serial blood sampling. The distributions of Hup A into rat brain tissues following intranasal dosing were compared with those after intravenous and intragastric dosing by tissue homogeneization. The therapeutics effects of Hup A nasal in situ gel on cognitive function were tested in mice and rats with Morris water maze, step down test and step through test. RESULTS: The AUC(0-->6 h) value in plasma obtained after nasal administration was 0.94 of that after intravenous administration, but the AUC(0-->6 h) of CSF after nasal administration was 1.3 and 2.3 times of that after intravenous and intragastric administration. The AUC(0-->6 h), of cerebrum, hippocampus, cerebellum, left olfactory bulb and right olfactory bulb after nasal administration were 1.5, 1.3, 1.0, 1.2 and 1.0 of that after intravenous administration, 2.7, 2.2, 1.9, 3.1 and 2.6 times of that after intragastric administration, respectively. Intranasal adminintration of 17.5-35 microg x kg(-1) showed equal effects after oral adminintration of 70 microg x kg(-1) commercial tablets, which was in good agreement with the results of pharmacokinetics. CONCLUSION: Intranasal administration of huperzine A nasal in situ gel significantly increased the distributions of Hup A into rat brain tissues, especially into cerebrum and hippocampus which should be the target areas of Hup A, and enhanced the brain targeting of Hup A.

Huperzine A protects C6 rat glioma cells against oxygen-glucose deprivation-induced injury

Wang ZF, Tang XC.

FEBS Lett. 2007 Jan 18;

State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, People's Republic of China.

The protective effects of huperzine A against oxygen-glucose deprivation (OGD)-induced injury in C6 cells were investigated. OGD for 6h and reoxygenation for 6h enhanced phosphorylation and degradation of IkappaBalpha and nuclear translocation of nuclear factor-kappa B (NF-kappaB), triggered overexpression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nitric oxide (NO) in C6 cells. Along with inhibiting acetylcholinesterase activity, treatment with 1muM huperzine A inhibited activation of NF-kappaB, attenuated iNOS, COX-2 and NO overexpression, and promoted survival in C6 cells subjected to OGD insult. The protective effects of huperzine A were partly mediated by "cholinergic anti-inflammatory pathway" through alpha7 nicotinic acetylcholine receptor.

PMID: 17257593 [PubMed - as supplied by publisher]

Huperzine A in rat plasma and CSF following intranasal administration

Yue P, Tao T, Zhao Y, Ren J, Chai X.

Int J Pharm. 2006 Dec 28

Division of Pharmaceutics, Shanghai Institute of Pharmaceutical Industry, ZhongShanBeiYi Road 1111, Shanghai 200437, China.

This paper presents to investigate the levels of Huperzine A in plasma and CSF of rats after three different kinds of administrations and to find out whether intranasal administration is the best root to transfer the drug into the CNS. The drugs of two doses (167 and 500mug/kg) were administered to male Sprague-Dawley rats intravenously, intranasally and intragastricly, respectively. Series plasma and cerebrospinal fluid (CSF) samples were collected from femoral artery and cisterna magna for 6h. The drug concentrations were determined by HPLC-fluorescence method. The AUC(plasma) and the AUC(CSF) of intranasal administration were 90.3% and 127.7% in low dose group (167mug/kg) and 91.3% and 69.4% in high dose group (500mug/kg) compared with intravenous administration. The AUC(plasma) and the AUC(CSF) of intragastric administration were 98.9% and 52.1% in high dose group (500mug/kg) compared with intravenous administration.

PMID: 17241758 [PubMed - as supplied by publisher]

Drug brain distribution following intranasal administration of Huperzine A in situ gel in rats.

Acta Pharmacol Sin. 2007 Feb;28(2):273-8

Zhao Y, Yue P, Tao T, Chen QH.

Shanghai Institute of Pharmaceutical Industry, Shanghai 200040, China. taotaosipi@hotmail.com.

Aim: To determine the uptake extent of Huperzine A (Hup A) into the brain after intranasal administration of Hup A in situ gel to rats, and to compare the pharmacokinetic parameters between intranasal administration and iv and po. Methods: Hup A was administered to male Sprague-Dawley rats via nasal, iv and oral routes at the dose of 166.7, 166.7, and 500 mug/kg, respectively. Blood and brain tissue samples including the cerebrum, hippocampus, cerebellum and olfactory bulb were collected, and the concentrations of Hup A in the samples were assayed by HPLC. The area under the concentration-time curve (AUC(0-->6 h)) and the ratio of the AUC(brain) to the AUC(plasma) (drug targeting efficiency, DTE) were calculated to evaluate the brain targeting efficiency of the drug via 3 administration routes. Results: The AUC(0-->6 h) of the drug in the cerebrum, hippocampus, cerebellum, left olfactory bulb and right olfactory bulb after intranasal administration of the Hup A in situ gel were 1.5, 1.3, 1.0, 1.2, and 1.0 times of those after iv administration of the injection, and 2.7, 2.2, 1.9, 3.1, and 2.6 times of those after administration of the oral formulation. The AUC (brain0-->6 h)/AUC(plasma0-->6 h) of Hup A in the cerebrum, hippocampus and left olfactory bulb following the intranasal administration dose were significantly higher (P<0.05) than the iv dose. Conclusion: Intranasal delivery showed a viable, non-invasive strategy for delivering the drug into brain.

PMID: 17241531 [PubMed - in process]

Sensitivity of butyrylcholinesterase knockout mice to (-)-huperzine A and donepezil suggests humans with butyrylcholinesterase deficiency may not tolerate these Alzheimer's disease drugs and indicates butyrylcholinesterase function in neurotransmission

Toxicology. 2006 Dec 2;

Duysen EG, Li B, Darvesh S, Lockridge O.

Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-6805, Unites States.

Butyrylcholinesterase (EC 3.1.1.8 BChE) is present in all human and mouse tissues, and is more abundant than acetylcholinesterase (EC 3.1.1.7 AChE) in all tissues except brain. People who have no BChE activity due to a genetic variation are healthy. This has led to the hypothesis that BChE has no physiological function. We tested this hypothesis by challenging BChE and AChE knockout mice, as well as wild-type mice, with the AChE specific inhibitors, (-)-huperzine A and donepezil, and with serine hydrolase inhibitors, echothiophate and chlorpyrifos oxon. (-)-Huperzine A and donepezil caused mortality and significant toxicity in the BChE-/- animals. The BChE heterozygote (BCHE+/-) mice with approximately one-half the BChE activity of the BChE wild type (BChE+/+) exhibited intermediate toxic symptoms, and survived a longer period. The BChE+/+ animals displayed comparatively minor toxic symptoms and recovered by 24h post-dosing. Plasma AChE activity was inhibited to the same extent in BChE-/-, +/-, and +/+ mice, whereas BChE activity was not inhibited. This indicated that the protective effect of BChE was not due to scavenging (-)-huperzine A. AChE-/- mice were unaffected by (-)-huperzine A and donepezil, demonstrating the specificity of these inhibitors for AChE. AChE-/- mice treated with chlorpyrifos oxon lost all BChE activity, had severe cholinergic symptoms and died of convulsions. This showed that BChE activity was essential for survival of AChE-/- mice. In conclusion, we propose that the protective effect of BChE is explained by hydrolysis of excess acetylcholine in physiologically relevant regions such as diaphragm, cardiac muscle, and brain. Thus, BChE has a function in neurotransmission. People with BChE deficiency are expected to be intolerant of standard doses of the anti-Alzheimer's drugs, (-)-huperzine A and donepezil.

PMID: 17194517 [PubMed - as supplied by publisher]

Plant metabolites as nootropics and cognitives]

Cervenka F,

Jahodar L.

Ceska Slov Farm. 2006 Sep;55(5):219-29.

Univerzita Karlova v Praze, Farmaceuticka fakulta v Hradci Kralove, Katedra farmaceuticke botaniky a ekologie. frantisek.cervenka@faf.cuni.cz

Nowadays several millions of people suffer from Alzheimer's disease and other types of dementia. Etiology of these diseases is not known very well. There occur different levels of neurotransmitters, the level of acetylcholine in the brain is decreased and pathological changes affect the brain tissue. Organic and toxic damage of the brain, free radicals, and other changes participate in the development of these diseases. Drugs as nootropics, cognitives, and neuroprotectives are commonly used to treat these diseases. Some of these drugs have often side and undesirable effects. In recent years some natural substances (galanthamine, huperzine A, vinpocetine), and standardized plant extracts (Ginkgo biloba L., Centella asiatica L.) Urban, Bacopa monniera L., Evolvulus alsinoides L.) are often used. These plant preparations produce fewer undesirable effects and the same effectiveness as the classic therapy, or these preparations are used as a supplement to the classic therapy.

Effect of huperzine A on cerebral cholinesterase and acetylcholine in elderly patients during recovery from general anesthesia

Nan Fang Yi Ke Da Xue Xue Bao. 2006 Nov;26(11):1660-2

Wang G, Zhang SQ, Zhan H.

Department of Anesthesia, People' s Hospital of Guangdong Province, Guangzhou 510080, China.

OBJECTIVE: To observe the effect of huperzine A on cerebral cholinergic system in elderly patients during recovery from general anesthesia. METHODS: Thirty elderly patients undergoing elective surgery under general anesthesia were randomized in a double-blind manner into group I (n=15) to receive huperzine A (0.3 mg/2 ml) and group II (n=15) with normal saline (2 ml) given intravenously. Huperzine A or normal saline was administered 30 min before completion of the operation, and acetylcholine (Ach) concentration in the cerebral spinal fluid (CSF) of the patients was determined using high-performance liquid chromatography with electrochemical detector (HPLC-ECD) and the activity of cholinesterase inhibitors (ChE) evaluated with automatic biochemistry analyzer before general anesthesia induction (T1) and 5 h after operation completion (T2). RESULTS: In both the groups, Ach concentration in the CSF were lower at T2 than that at T1 (P<0.01), and at T2, CSF Ach concentration was significantly higher in group I than in group II (P<0.01); in group I, the activity of CSF ChE at T2 was lower than that at T1 (P<0.01), and also lower than at T2 in group II (P<0.01). CONCLUSION: Huperzine A can inhibit cholinesterase to increase Ach, which has a positive effect on cerebral cholinergic system in elderly patients during recovery from general anesthesia.

PMID: 17121726 [PubMed - in process]

Neuroprotective effects of huperzine A: new therapeutic targets for neurodegenerative disease.

Zhang HY, Tang XC.

Trends Pharmacol Sci. 2006 Dec;27(12):619-25. Epub 2006 Oct 23

State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhangjiang Hi-Tech Park, Shanghai 201203, China.

In recent years, the most common pharmacological treatment for Alzheimer's disease (AD) has been acetylcholinesterase (AChE) inhibition. However, this single-target approach has limited effectiveness and there is evidence that a multitarget approach might be more effective. Huperzine A (HupA), a novel alkaloid isolated from a Chinese herb, has neuroprotective effects that go beyond the inhibition of AChE. Recent data have demonstrated that HupA can ameliorate the learning and memory deficiency in animal models and AD patients. Its potentially beneficial actions include modification of beta-amyloid peptide processing, reduction of oxidative stress, neuronal protection against apoptosis, and regulation of the expression and secretion of nerve growth factor (NGF) and NGF signaling.

PMID: 17056129 [PubMed - indexed for MEDLINE]

Effects of huperzine A on memory deficits and neurotrophic factors production after transient cerebral ischemia and reperfusion in mice.

Wang ZF, Tang LL, Yan H, Wang YJ, Tang XC

Pharmacol Biochem Behav. 2006 Apr;83(4):603-11. Epub 2006 May 9

State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, PR China.

This study is to investigate the effects of huperzine A on memory deficits, neuronal damage and neurotrophic factors production after transient cerebral ischemia and reperfusion in mice, as well as the potential downstream signaling pathway. Bilateral common carotid occlusion (BCCAo) combined with systemic hypotension induced severe memory deficits in a water maze task and neuronal degeneration in cerebral cortex and hippocampus in mice. Oral administration of huperzine A (0.2 mg/kg, once per day, started 2 days before surgery and lasted for 7 days after surgery) markedly attenuated the memory deficits and neuronal damage. Meanwhile, huperzine A significantly increased the mRNA and protein levels of NGF, BDNF and TGF-beta(1), and potentiated phosphorylation of MAPK/ERK 1/2 in both cerebral cortex and hippocampus compared with transient cerebral ischemia and reperfusion group. This study provides evidence for the protective effects of huperzine A against transient cerebral ischemia and reperfusion in mice, and suggests potentially important roles that neurotrophic factors might play in these effects. It also indicates that the MAPK/ERK pathway might be involved in the in vivo neurotrophic effects of huperzine A against transient cerebral ischemia and reperfusion.

Herbal medicine in the treatment of Alzheimer's disease

Akhondzadeh S, Abbasi SH.

Am J Alzheimers Dis Other Demen. 2006 Mar-Apr;21(2):113-8

Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Alzheimer's disease (AD) is characterized by profound memory loss sufficient to interfere with social and occupational functioning. It is the most common form of dementia, affecting more than 20 million people worldwide. AD is characterized by an insidious loss of memory, associated functional decline, and behavioral disturbances. Patients may live for more than a decade after they are diagnosed with AD, making it the leading cause of disability in the elderly. The incidence of AD ranges from 1 to 4 percent of the population per year, rising from its lowest level at ages 65 to 70 years to rates that may approach 6 percent for those over the age of 85 years. The first neurotransmitter defect discovered in AD involved acetylcholine (ACh). As cholinergic function is required for short-term memory, the cholinergic deficit in AD was also believed to be responsible for much of the short-term memory deficit. Clinical drug trials in patients with AD have focused on drugs that augment levels of ACh in the brain to compensate for the loss of cholinergic function. These drugs have included ACh precursors, muscarinic agonists, nicotinic agonists, and acetylcholinesterase inhibitors. The most highly developed and successful approaches to date have employed acetylcholinestrase inhibition. Although some Food and Drug Administration-approved drugs are available for the treatment of Alzheimer's disease, the outcomes are often unsatisfactory, and there is a place for alternative medicine, in particular, herbal medicine. This paper reviews the clinical effects of a number of commonly used types of herbal medicines for the treatment of AD.

PMID: 16634467 [PubMed - indexed for MEDLINE]

Effects of a memory enhancing peptide on cognitive abilities of brain-lesioned mice: additivity with huperzine A and relative potency to tacrine

Xu Z, Zheng H, Law SL, Dong So D, Han Y, Xue H.

J Pept Sci. 2006 Jan;12(1):72-8

Department of Biochemistry, Hong Kong University of Science and Technology, Hong Kong, China.

Alzheimer's disease (AD) and related dementing disorders having cognitive manifestations represent an increasing threat to public health. In the present study, the effects of a memory enhancing NLPR tetra-peptide (MEP), huperzine A (Hup A), or a combination of the two on the cognitive abilities of brain-lesioned mice were evaluated and compared with tacrine in the passive avoidance and Y-water maze tests for the acquisition and retention aspects of cognitive functions. MEP at microg kg(-1) doses, and Hup A or tacrine at mg kg(-1) doses significantly reversed the cognition deficits induced by scopolamine. For acquisition ability, it was observed that mice administered with MEP (4.0 microg kg(-1)) spent less time escaping onto the platform in the water maze than those treated with tacrine (1.5 mg kg(-1)); whereas for memory retention, tacrine-administration resulted in a higher step-through latency in mice at the tested dose regime. In addition, co-administration of MEP (2.0 microg kg(-1)) and Hup A (0.1 mg kg(-1)) exhibited an additive effect resulting in considerable improvements in both acquisition and retention abilities of brain-lesioned mice. The results demonstrated that MEP was highly efficient in the rescue of cognitive abilities of brain-lesioned mice and in particular, the effective doses of MEP were about two orders of magnitude lower than that of tacrine, a therapeutic currently used in the treatment of AD. Moreover, MEP and Hup A were effective at reduced doses when the two were co-administered, providing a rationale for their combined usage in the treatment of cognitive deficits. Copyright (c) 2005 European Peptide Society and John Wiley & Sons, Ltd.

PMID: 15942937 [PubMed - indexed for MEDLINE]

Huperzine-A capsules enhance memory and learning performance in 34 pairs of matched adolescent students.

Sun QQ, Xu SS, Pan JL, Guo HM, Cao WQ.

Zhongguo Yao Li Xue Bao. 1999 Jul;20(7):601-3. Xiaoshan Mental Hospital, Zhejiang, China.

AIM: To study the efficacy of huperzine-A capsules (Hup) on memory and learning performance of adolescent students. METHODS: Using double-blind and matched pair method, 34 pairs of junior middle school students complaining of memory inadequacy were divided into two groups by normal psychological health inventory (PHI), similar memory quotient (MQ), same sex and class. The Hup group was administrated orally 2 capsules of Hup (each contains Hup 50 micrograms) b.i.d., and the placebo group was given 2 capsules of placebo (starch and lactose inside) b.i.d. for 4 wk. RESULTS: At the end of trial, the Hup group's MQ (115 +/- 6) was more than that of the placebo group (104 +/- 9, P < 0.01), and the scores of Chinese language lesson in the Hup group were elevated markedly too. CONCLUSION: The Hup capsules enhance the memory and learning performance of adolescent students.

Comparative studies of huperzine A, donepezil, and rivastigmine on brain acetylcholine, dopamine, norepinephrine, and 5-hydroxytryptamine levels in freely-moving rats

Liang YQ, Tang XC.

Acta Pharmacol Sin. 2006 Sep;27(9):1127-36

State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Instituties for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 201203, China.

AIM: To assess the effects of cholinesterase inhibitors huperzine A, donepezil and rivastigmine on cerebral neurotransmitters in the cortex and hippocampus in freely-moving rats. METHODS: Double-probe cerebral microdialysis and HPLC with electrochemical detection were used to detect neurotransmitters. RESULTS: Our results showed that huperzine A (0.25, 0.5, and 0.75 micromol/kg, po) dose-dependently elevated extracellular acetylcholine (ACh) levels in the medial prefrontal cortex (mPFC) and hippocampus. Oral administration of donepezil (5.4 micromol/kg) or rivastigmine (1 micromol/kg) also elicited significant increases in ACh in the mPFC and hippocampus. The time course of cortical acetylcholinesterase (AChE) inhibition with the 3 inhibitors mirrored the increases of ACh at the same dose. The marked elevation of ACh after oral administration of huperzine A (0.5 micromol/kg) and donepezil (5.4 micromol/kg) was associated with a significantly increased release of dopamine (DA) in the mPFC or hippocampus. None of the 3 inhibitors affected norepinephrine (NE) and 5-hydroxytryptamine (5-HT) levels in the mPFC and hippocampus. The effects of huperzine A and rivastigmine did not depend on the route of administration, but donepezil was less efficacious by the oral route than by ip injection. The ability of huperzine A to increase ACh levels was unchanged when tests were performed after multiple oral administration of the drug at 0.5 micromol/kg, once per day for 30 d. CONCLUSION: The present findings showed that, in molar terms, huperzine A had similar potency on increasing mPFC ACh and DA levels as compared to the 11- and 2-fold dosages of donepezil and rivastigmine, respectively, and had longer lasting effects after oral dosing.

Comparative effects of huperzine A, donepezil and rivastigmine on cortical acetylcholine level and acetylcholinesterase activity in rats

Liang YQ, Tang XC.

Neurosci Lett. 2004 May 6;361(1-3):56-9.

State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China.

The cholinesterase inhibitors huperzine A, donepezil and rivastigmine were compared for their effects on extracellular acetylcholine concentration and acetylcholinesterase activity in the rat cortex. After i.p. injection, huperzine A (0.25-0.75 micromol/kg), donepezil (2-6 micromol/kg) and rivastigmine (0.75-1.5 micromol/kg) dose-dependently elevated the concentration of acetylcholine. The duration of huperzine A was longest. The time courses of cortical acetylcholinesterase inhibition with middle doses of these agents mirrored the increases of acetylcholine at the same doses. However, acetylcholinesterase inhibition was disproportionately greater after middle dose of rivastigmine than doses of huperzine A and donepezil that increased acetylcholine to a similar extent. Muscle fasciculation appeared only after donepezil with a dose-dependent incidence and intensity. In molar terms, huperzine A was 8- and 2-fold more potent than donepezil and rivastigmine, respectively, in increasing cortical acetylcholine levels, with a longer-lasting effect.