Effect of Choto-san, a Kampo medicine, on impairment of passive avoidance performance in senescence accelerated mouse (SAM)

Protective effects of a Chotosan Fraction and its active components on β-amyloid-induced neurotoxicity

Chotosan (CTS) is a traditional Kampo prescription used to treat chronic headache and hypertension. Recent clinical studies demonstrated that CTS has ameliorative effects on dementia. This study aims to identify the anti-Alzheimer components in CTS. β-amyloid (Aβ) is considered to play a central role in the pathophysiology of Alzheimer's disease. CTS-E, a fraction of CTS, showed significant protective effects on Aβ-induced neurotoxicity. High-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used for the qualitative analysis of it. Among the identified constituents, neuroprotective effects against Aβ(25-35)-induced neurotoxicity of 10 major compounds were tested by MTT assay. Their inhibitory action on Aβ(1-42) self-induced aggregation was measured by Thioflavin T-binding assay. The results showed that caffeic acid, chlorogenic acid, 1,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid had significant neuroprotective effects on Aβ(25-35)-induced neurotoxicity. Besides these phenolic acids, nobiletin and hesperidin could also inhibit Aβ(1-42) self-induced aggregation. In conclusion, the neuroprotective fraction, CTS-E, could protect PC12 cells from Aβ-induced neurotoxicity. Anti-oxidative effects may at least partly mediate the neuroprotective effects of it. Phenolic acids from Chrysanthemi Flos and flavonoids from Citri Reticulatae Pericarpium might be the effective constituents in CTS-E.

Danggui-Shaoyao-San: New Hope for Alzheimer's Disease

Danggui-Shaoyao-San (DSS), also called Toki-shakuyaku-san (TJ-23) or Dangguijakyak-san (DJS), is a well-known herbal formula (Angelica sinensis (Oliv.) Diels., Ligusticum chuanxiong Hort., Paeonia lactiflora pall., Poria cocos (Schw.) Wolf, Alisma orientalis (Sam.) Juzep., Atractylodes macrocephala Koidz.), which has been widely used in oriental countries for the treatment of various gynecological diseases. Recent studies show that DSS has an effect on free radical-mediated neurological diseases and exhibits anti-inflammatory and antioxidant activities and reduces cell apoptosis in the hippocampus. In addition, DSS mediates the modulation of central monoamine neurotransmitter systems and ameliorates dysfunction of the central cholinergic nervous system and scopolamine-induced decrease in ACh levels. DSS improves the function of the dopaminergic, adrenergic, and serotonergic nervous systems. Interestingly, DSS can alleviate cognitive dysfunction of Alzheimer's disease (AD) patients, suggesting that it is a useful therapeutic agent for AD. This paper reviews the mechanism of DSS for the treatment of AD.

Effects of Fructus Akebiae on learning and memory impairment in a scopolamine-induced animal model of dementia

Fructus Akebiae (FAE) is a component of traditional Chinese medicines used for the clinical treatment of amnesia. The aim of the present study was to investigate the effects of FAE extract on scopolamine-induced learning and memory impairment in mice and Sprague-Dawley rats. Treatment with FAE (2.5, 5 and 10 mg/kg) was investigated in scopolamine-treated animals, and its effects on different types of memory were examined using the T-maze, the Morris water maze task, the novel object recognition test, the passive avoidance task and the step-down test. The results revealed that 5 and 10 mg/kg FAE attenuated scopolamine-mediated impairment of cognition, including spatial, episodic, aversive, and short- and long-term memory. Overall, these results suggest that FAE is an effective cognitive enhancer, and thus highlights the value of a multi-target strategy to address the complexity of cognitive dysfunction in Alzheimer’s disease.

Role of oligomeric proanthocyanidins derived from an extract of persimmon fruits in the oxidative stress-related aging process

Many researchers have focused on the oligomeric form of proanthocyanidins with a lower level of polymerization found in foodstuffs such as grape seeds and blackberries. The present study indicated that the oral administration of oligomers isolated from persimmon fruits extended the lifespan of senescence-accelerated mouse prone/8 (SAMP8), a murine model of accelerated senescence. On the other hand, oligomer-treated SAMP8 did not show stereotypical behavior. We also revealed that the oral administration of oligomers improved spatial and object recognition memory in SAMP8. The density of axons in the hippocampal CA1 was significantly increased by oligomer administration. Moreover, the administration of oligomers increased the phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2 in the hippocampal CA3, hypothalamus, and choroid plexus. We speculate that memory improvement accompanied by histological changes may be induced directly in the hippocampus and indirectly in the hypothalamus and choroid plexus through VEGFR-2 signaling. In the present study, we elucidated the protective effect of oligomers against memory impairment with aging. VEGFR-2 signaling may provide a new insight into ways to protect against memory deficit in the aging brain.

Danggui-Shaoyao-San Improves Learning and Memory in Female SAMP8 via Modulation of Estradiol

Previous studies showed that Danggui-Shaoyao-San (DSS), a traditional Chinese medicinal prescription, could alleviate cognitive dysfunction of Alzheimer's disease (AD) patients. However, the mechanisms remain unclear; we have now examined the effect of DSS on SAMP8 and elucidated the possible mechanism. Animals were treated with DSS for 2 months, and step-down test and Morris water maze (MWM) test were used to evaluated cognitive abilities. The estradiol (E2), NO, and glycine in blood plasma or in hippocampus were detected to explore the possible mechanisms. The latency of SAMP8 in step-down test was shorter than that of age-matched SAMR1, and DSS increased the latency especially in female animals. In MWM test, we got similar results; SAMP8 spent more time to find the platform, and DSS decreased the time before finding the platform, with little effect on swim velocity, during the training sessions. During test session, DSS increased the time spent in target quadrant especially in female SAMP8. In female SAMP8, plasma E2, NO, and glycine were elevated in plasma or hippocampus tissue. In conclusion, DSS could ameliorate deterioration of cognition in SAMP8, especially in female animals. Increasing E2, NO, and glycine might contribute to the cognitive improvement effect of DSS in female SAMP8.

The effect of PN-1, a Traditional Chinese Prescription, on the Learning and Memory in a Transgenic Mouse Model of Alzheimer's Disease

Traditional Chinese Medicine (TCM) is a complete medical system that has been practiced for more than 3000 years. Prescription number 1 (PN-1) consists of several Chinese medicines and is designed according to TCM theories to treat patients with neuropsychiatric disorders. The evidence of clinical practice suggests the benefit effects of PN-1 on cognitive deficits of dementia patients. We try to prove and explain this by using contemporary methodology and transgenic animal models of Alzheimer's disease (AD). The behavioral studies were developed to evaluate the memory of transgenic animals after intragastric administration of PN-1 for 3 months. Amyloid beta-protein (A β ) neuropathology was quantified using immunohistochemistry and ELISA. The western blotting was used to detect the levels of plasticity associated proteins. The safety of PN-1 on mice was also assessed through multiple parameters. Results showed that PN-1 could effectively relieve learning and memory impairment of transgenic animals. Possible mechanisms showed that PN-1 could significantly reduce plaque burden and A β levels and boost synaptic plasticity. Our observations showed that PN-1 could improve learning and memory ability through multiple mechanisms without detectable side effects on mice. We propose that PN-1 is a promising alternative treatment for AD in the future.

Autocrine motility factor receptor is involved in the process of learning and memory in the central nervous system

The autocrine motility factor receptor (AMFR) is a multifunctional protein involved in cellular adhesion, proliferation, motility and apoptosis. Our study showed that increased AMFR protein expression in the hippocampus of KM mice correlated with enhanced capacity for learning and memory following the shuttle-box test and was significantly elevated in the highest score group. Also, AMF and AMFR mRNA expression positively correlates with the mRNA expression of the synapse marker synaptophysin (Syp). Aging studies in the senescence-accelerated mouse strain (SAM) prone/8 (SAMP8), an animal model of Alzheimer's disease (AD), revealed significantly decreased mRNA and protein expression of AMF and AMFR in the hippocampus. This is especially true for AMFR and AMF protein expression compared with age-matched SAM resistant/1 (SAMR1) mouse strain as the control. Additionally, the low mRNA expression of AMFR could be up-regulated by the four nootropic traditional Chinese medicinal prescriptions (TCMPs): Ba-Wei-Di-Huang decoction (BW), Huang-Lian-Jie-Du decoction (HL), Dang-Gui-Shao-Yao-San (DSS) and Tiao-Xin-Fang decoction (TXF). AMFR protein expression could be up-regulated by two TCMPs, Liu-Wei-Di-Huang decoction (LW) and BW. This indicated that AMFR is involved in the process of learning and memory in the central nervous system. These results may provide useful clues for understanding the etiology of AD.

Danggui-Shaoyao-San and its active fraction JD-30 improve Abeta-induced spatial recognition deficits in mice

AIMS OF THE STUDY

Previous studies showed that Danggui-Shaoyao-San (DSS), a traditional Chinese medicinal prescription, could alleviate cognitive dysfunction of Alzheimer's disease (AD) patients. However, the mechanism and substance basis remain unknown. JD-30 is a fraction extracted from DSS, whose activity we previously was evaluated. beta-Amyloid (Abeta) is believed to be a critical etiological factor of AD. We have now examined the effect of DSS and JD-30 on AD model mice induced by Abeta, and elucidated the possible mechanism.

MATERIALS AND METHODS

Mice were intracerebroventricular injected with the aggregated Abeta(25-35) to mimic AD. Groups of mice were treated with DSS or JD-30 by intragastric infusion over 2 weeks, and their spatial learning and memory capacities were measured by the Morris water maze procedure. The mechanisms were investigated by extracellular microelectrode recordings, and also electron microscopy.

RESULTS

Our results show that Abeta(25-35) induced impairment of spatial learning and memory in mice, as well as inhibition of long-term potentiation (LTP) in the hippocampus. The impairments were ameliorated by DSS or JD-30 administration. Additionally, JD-30 not only prevented the aggregation of Abeta(25-35), but disrupted aggregated Abeta(25-35) fibrils.

CONCLUSION

These results suggest that JD-30 is one of the chief active fractions extracted from DSS by its ability to ameliorate deterioration of cognition, and by blocking and disrupting the aggregation of Abeta so that synaptic plasticity was improved, which may be one of the mechanisms involved.

Oligomeric proanthocyanidins improve memory and enhance phosphorylation of vascular endothelial growth factor receptor-2 in senescence-accelerated mouse prone/8

Senescence-accelerated mouse prone/8 (SAMP8), a murine model of accelerated senescence, shows age-related deficits in learning and memory. We investigated the effect of oligomeric proanthocyanidins (oligomers) on memory impairment using the SAMP8 model involving the oral administration of oligomers for 5 weeks. To analyse memory improvement in SAMP8, we performed Morris water maze, object location and object recognition tests. The oral administration of oligomers improved spatial and object recognition impairment in SAMP8. Expressions of phosphorylated neurofilament-H (P-NF-H, axon marker), microtubule-associated proteins (MAP) 2a and 2b (MAP2; dendrite marker) and synaptophysin were increased in the brains of SAMP8-administered oligomers. In particular, the expression of P-NF-H was significantly elevated in the hippocampal CA1. This indicates that oligomers result in an increase in the densities of axons, dendrites and synapses. To investigate the protective mechanisms of oligomers against brain dysfunction with ageing, we carried out a receptor tyrosine kinase phosphorylation antibody array, and clarified that the administration of oligomers led to an increase in the phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2, suggesting the neuroprotective role of oligomers. The phosphorylation of VEGFR-2 was more greatly increased in the hypothalamus and choroid plexus than in other brain regions of SAMP8. Memory in oligomer-treated mice was impaired by SU1498, a VEGFR-2-specific antagonist. Elucidating the relationship between memory impairment with ageing and VEGFR-2 signalling may provide new suggestions for protection against memory deficit in the ageing brain.

Determination of the effectiveness of components of the herbal medicine Toki-Shakuyaku-San and fractions of Angelica acutiloba in improving the scopolamine-induced impairment of rat's spatial cognition in eight-armed radial maze test

The improving effects of various components of Toki-Shakuyaku-San (TSS) and fractions isolated from Angelica acutiloba Radix (Toki) on scopolamine-induced spatial memory impairment were investigated in eight-armed radial maze. The scopolamine-induced memory impairment was characterized by prominent increase of error choices in addition to decreased correct choices. Toki, Cnidium officinale Rhizoma (Senkyu), Poria cocos Hoelen (Bukuryo), Alisma orientale Rhizoma (Takusha), and Atractylodes lancea Rhizoma (Sojutsu) increased the correct choices, while only the Toki, Sojutsu, and Takusha decreased the error choices. No effect was produced by Paeonia lactiflora Radix (Shakuyaku). Investigation of effects of fractions isolated from Toki revealed that its activity mainly resided in the butanol layer and its contents of N-methyl-beta-carboline-3-carboxamide and amines. Moreover, the alkaloid, internal and external solutions (containing poly-, di-, and monosaccharides) obtained by dialysis with Visking cellophane tubing also improved the memory. However, no improving properties were detected for methanol and hexanol layers, L-(-)-tryptophan, L-arginine, L-(-)-lysine, and choline chloride. The results showed that the TSS components could improve the reference and working memory impaired by scopolamine. The improving effect of TSS is produced greatly by the Toki component, the activity of which was greatly produced by the fraction extracted by butanol.

Therapeutic effects of herbal extracts and constituents in animal models of psychiatric disorders

A search for novel pharmacotherapy from medicinal plants for psychiatric illnesses has progressed significantly in the past decade. This is reflected in the large number of herbal preparations for which psychotherapeutic potential has been evaluated in a variety of animal models. The objective of this review is to provide an overview of herbal extracts and constituents that have significant therapeutic effects in animal models of psychiatric illnesses. Eighty five individual herbs reviewed were classified as anxiolytic, antidepressant, neuroleptic, antidementia, or anti-substance abuse herbs. The full scientific name of each herb, herbal part used, active constituent, extract, dose range and route, animal model, possible mechanisms of action, and pertinent references are presented via synoptic tables. The herbal mixtures were also mentioned. A considerable number of herbal constituents whose behavioral effects and pharmacological actions have been well characterized may be good candidates for further investigations that may ultimately result in clinical use. The investigation of a large portion of the herbal extracts and herbal mixtures is in its infancy. Herbal remedies that have demonstrable psychotherapeutic activities have provided a potential to psychiatric pharmaceuticals and deserve increased attention in future studies.