Loganin improves learning and memory impairments induced by scopolamine in mice

Azo food dye neurotoxicity in rats: A neurobehavioral, biochemical, and histopathological study

Azo Food dyes (AFDs), which are widely used in the food industry, may be associated with adverse health effects. We have investigated the effects of the AFDs metanil yellow (MY), malachite green (MG), and sudan III (SIII) on cognitive impairment, oxidative stress, mitochondrial dysfunction, neuro-enzyme activities, and histopathology in rats. Rats treated with MY (430 mg/kg), MG (13.75 mg/kg), SIII (250 mg/kg), and a mixture (MY 143.33 + MG 4.52 + SIII 83.33 mg/kg) p.o. for 60 d showed significant learning and memory impairments. Significant biochemical changes were observed in the rat frontal cortex and hippocampus: increases in lipid peroxidation and the activity of acetylcholinesterase (AChE); decreases in the level of reduced glutathione and the activities of catalase, superoxide dismutase, and mitochondrial complexes I and II. Histological damage to brain neurons accompanied the learning and memory impairments and was linked with other biochemical and neurochemical alterations.

The Potential Neuroprotective Effect of Thymoquinone on Scopolamine-Induced In Vivo Alzheimer's Disease-like Condition: Mechanistic Insights

BACKGROUND

Alzheimer's disease (AD) is a common neurodegenerative disorder without effective treatment. Thymoquinone (TQ) has demonstrated potential in exhibiting anti-inflammatory, anti-cancer, and antioxidant characteristics. Despite TQ's neuroprotection effect, there is a scarcity of information regarding its application in AD research, and its molecular trajectories remain ambiguous. Thus, the objective of the current investigation was to examine the potential beneficial effects and underlying mechanisms of TQ in scopolamine (SCOP)-induced neuronal injury to mimic AD in vivo model.

METHODS

Thirty mice were divided into normal, SCOP, and TQ groups. The Y-maze and pole climbing tests were performed to measure memory and motor performance. Afterwards, histopathological and immunohistochemical examinations were carried out. Furthermore, peroxisome proliferator-activated receptor gamma (PPAR-γ) signaling pathway-related proteins and genes were detected with an emphasis on the role of miR-9.

RESULTS

TQ has the potential to ameliorate cognitive deficits observed in SCOP-induced AD-like model, as evidenced by the improvement in behavioral outcomes, histopathological changes, modulation of the expression pattern of PPAR-γ downstream targets with a significant decrease in the deposition of amyloid beta (Aβ).

CONCLUSIONS

TQ provided meaningful multilevel neuroprotection through its anti-inflammatory and its PPAR-γ agonist activity. Consequently, TQ may possess a potential beneficial role against AD development.

Whether the Subacute MPTP-Treated Mouse is as Suitable as a Classic Model of Parkinsonism

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model is one of the most common animal models for Parkinson's disease (PD). It is classified into three types: acute, subacute, and chronic intoxication models. The subacute model has attracted much attention for its short period and similarity to PD. However, whether subacute MPTP intoxication in mouse mimics the movement and cognitive disorders of PD still remains highly controversial. Therefore, the present study reassessed the behavioral performances of subacute MPTP intoxication in mice using open field, rotarod, Y maze,  and gait analysis at different time points (1, 7, 14, and 21 days) after modeling. Results of the current study showed that although MPTP-treated mice using subacute regimen showed severe dopaminergic neuronal loss and evident astrogliosis, they failed to display significant motor and cognitive deficits. Besides, expression of mixed lineage kinase domain-like (MLKL), a marker of necroptosis, was also significantly increased in the ventral midbrain and striatum of MPTP-intoxicated mice. This evidently implies that necroptosis may play an important role in MPTP-induced neurodegeneration. In conclusion, the findings of the present study suggest that subacute MPTP-intoxicated mice may not be a suitable model for studying parkinsonism. However, it can help in revealing the early pathophysiology of PD and studying the compensatory mechanisms which occur in early PD that prevent the emergence of behavioral deficits.

Iridoids and active ones in patrinia: A review

Iridoid is a special class of monoterpenoids, whose basic skeleton is the acetal derivative of antinodilaldehyde with a bicyclic H-5/H-9β, β-cisfused cyclopentan pyran ring. They were often existed in Valerianaceae, Rubiaceae, Scrophulariaceae and Labiaceae family, and has various biological activities, such as anti-inflammatory, hypoglycemic, neuroprotection, and soon. In this review, iridoids from Patrinia (Valerianaceae family), and the active ones as well as their mechanisms in recent 20 years were summarized. Up to now, a total of 115 iridoids had been identified in Patrinia, among which 48 had extensive biological activities mainly presented in anti-inflammatory, anti-tumor and neuroprotective. And the mechanisms involved in MAPK, NF-κB and JNK signal pathways. The summary for iridoids and their activities will provide the evidence to exploit the iridoids in Patrinia.

Influence of Murraya koenigii extract on diabetes induced rat brain aging

Food supplements are used to improve cognitive functions in age-related dementia. This study was designed to determine the Murraya koenigii leaves' effect on Alloxan-induced cognitive impairment in diabetic rats and the contents of oxidative stress biomarkers, catalase, reduced glutathione, and glutathione reductase in brain tissue homogenates. Wistar rats were divided into seven groups (six rats per group). Group I received saline water (1 ml, p.o.), Diabetes was induced in Groups II-VII with Alloxan (120 mg/kg/p.o). Group III was provided with Donepezil HCl (2.5 mg/kg/p.o.), Group IV, V, VI, and VII with Murraya koenigii ethanol extract (200 and 400 mg/kg/p.o.) and aqueous extract (200 and 400 mg/kg/p.o.), respectively, for 30 days. Behavior, acetylcholinesterase (AChE) activity, oxidative stress status, and histopathological features were determined in the hippocampus and cerebral cortex. Administration of Murraya koenigii ethanolic and aqueous extracts significantly (P<0.05, P<0.001) increased the number of holes crossed by rats from one chamber to another. There was an increase in the (1) latency to reach the solid platform, (2) number of squares traveled by rats on the 30^th day, and (3) percentage of spontaneous alternation behavior compared to the control group. Administration for successive days markedly decreased AChE activity (P<0.05), decreased TBARS level, and increased catalase, GSH, and GR levels. Murayya koenigii could be a promising food supplement for people with dementia. However, more research into sub-chronic toxicity and pharmacokinetic and pharmacodynamics interactions is essential.

Bacillus subtilis and Bifidobacteria bifidum Fermentation Effects on Various Active Ingredient Contents in Cornus officinalis Fruit

Microbial fermentation has been widely used to improve the quality and functional composition of food and edibles; however, the approach has rarely been applied to traditional Chinese medicines. In this study, to understand the effect of microbial fermentation on the active ingredients of traditional Chinese medicines, we used Bifidobacterium bifidum and Bacillus subtilis to ferment the traditional Chinese medicine, Cornus officinalis fruit (COF), and determined the levels of active ingredients using HPLC (high-performance liquid chromatography). According to the results, both B. subtilis and B. bifidum substantially increased the amount of gallic acid in the COF culture broth after fermentation; however, the two species of bacteria had no effect on the loganin content. Moreover, the B. subtilis fermentation reduced the contents of ursolic acid and oleanolic acid in the COF broth, whereas the B. bifidum fermentation did not. This study contributes to a better understanding of the mechanism by which microbial fermentation alters the active ingredient levels of traditional Chinese medicines, and suggests that fermentation may potentially improve their functional ingredients.

Magnoflorine-Loaded Chitosan Collagen Nanocapsules Ameliorate Cognitive Deficit in Scopolamine-Induced Alzheimer's Disease-like Conditions in a Rat Model by Downregulating IL-1β, IL-6, TNF-α, and Oxidative Stress and Upregulating Brain-Derived Neurotrophic Factor and DCX Expressions

Dementia or the loss of cognitive functioning is one of the major health issues in elderly people. Alzheimer's disease (AD) is one of the common forms of dementia. Treatment chiefly involves the use of acetylcholinesterase (AChE) inhibitors in AD. However, oxidative stress has also been found to be involved in the proliferation of the disease. Magnoflorine is one of the active compounds of Coptidis Rhizoma and has high anti-oxidative properties. Active principle-loaded nanoparticles have shown increased efficiency for neurodegenerative diseases due to their ability to cross the blood-brain barrier more easily. An in vitro study involving magnoflorine-loaded chitosan collagen nanocapsules (MF-CCNc) has shown them to possess inhibitory effects against oxidative stress and to some extent on AChE as well. In the current study, both nootropic and anti-amnesic effects of magnoflorine and MF-CCNc on scopolamine-induced amnesia in rats were evaluated. The treatment was done intraperitoneally (i.p.) once daily for 17 consecutive days with MF-CCNc (0.25, 0.5, and 1 mg), magnoflorine (1 mg), and donepezil (1 mg). To induce amnesia, hence, cognitive deficit rats were induced with scopolamine (1 mg/kg) daily for the last 9 days. Novel object recognition (NOR) and elevated plus maze (EPM) behavioral analysis were done to assess memory functioning. Hippocampal tissues were extracted to study the effect on biochemicals (AChE, MDA, SOD, and CAT), pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), and immunohistochemistry (brain-derived neurotrophic factor (BDNF) and DCX). MF-CCNc showed memory-enhancing effects in nootropic as well as chronic scopolamine-treated rats in NOR and an increase in inflexion ratio in EPM. MF-CCNc reduced the levels of AChE and MDA while increasing SOD and CAT levels in the hippocampus. MF-CCNc further lowered the levels of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. These nanocapsules further increased the expression of BDNF and DCX that are necessary for adult neurogenesis. From the research findings, it can be concluded that MF-CCNc has high anti-amnesic properties and could be a promising candidate for the treatment of AD.

Ameliorative effect of vanillin on scopolamine-induced dementia-like cognitive impairment in a mouse model

Background

Alzheimer’s disease (AD) is the most common form of dementia, which is among the top five causes of death in the United States. It is a neurodegenerative disorder that causes permanent loss of memory and cognition. The current pharmacotherapy for AD is based on providing symptomatic relief only and has many side effects. There is a need for a safer, disease-modifying drug for the treatment of AD.

Experimental approach

The PASS online software was used to screen phytoconstituents based on their predicted effects on various AD-related targets. Vanillin was selected as the compound of interest, as it has not been researched elaborately on any animal model of AD. The acetylcholinesterase inhibitory activity of vanillin was established in vitro. Thereafter, ameliorative effect of vanillin was evaluated using the exteroceptive memory model in scopolamine-induced cognitive impairment mice model.

Results

Vanillin showed an acetylcholinesterase inhibitory activity in vitro, and the IC50 value was calculated to be 0.033 mM. Vanillin significantly reversed the memory and behavioral deficits caused by scopolamine as demonstrated by significant improvement in memory in negative reinforcement, elevated plus maze, and spatial learning paradigms. Vanillin also proved to have a nootropic effect. Also, vanillin proved to have significantly better antioxidant and acetylcholinesterase inhibitory effects in vivo than donepezil hydrochloride. The potential anti-AD activity of vanillin was also confirmed by the reduction in IL-6 levels and TNF-α levels.

Conclusion

Our results suggest that vanillin is a safe and effective natural drug candidate having a great potential for the treatment of AD. However, more research is required to evaluate its effect on A beta plaques and Tau neurofibrillary tangles in vivo.

Phytochemistry, synthesis, analytical methods, pharmacological activity, and pharmacokinetics of loganin: A comprehensive review

Iridoid glycosides (IGs) are found in many medicinal and edible plants, such as Gardenia jasminoides, Cistanche tubulosa, Eucommia ulmoides, Rehmanniae Radix, Lonicera japonica, and Cornus officinalis. Loganin, an IG, is one of the main active ingredient of Cornus officinalis Sieb. et Zucc., which approved as a medicinal and edible plant in China. Loganin has been widely concerned due to its extensive pharmacological effects, including anti-diabetic, antiinflammatory, neuroprotective, and anti-tumor activities, etc. Studies have shown that these underlying mechanisms include anti-oxidation, antiinflammation and anti-apoptosis by regulating a variety of signaling pathways, such as STAT3/NF-κB, JAK/STAT3, TLR4/NF-κB, PI3K/Akt, MCP-1/CCR2, and RAGE/Nox4/p65 NF-κB signaling pathways. In order to better understand the research status of loganin and promote its application in human health, this paper systematically summarized the phytochemistry, analysis methods, synthesis, pharmacological properties and related mechanisms, and pharmacokinetics based on the research in the past decades.

A standardized black pepper seed extract containing β-caryophyllene improves cognitive function in scopolamine-induced amnesia model mice via regulation of brain-derived neurotrophic factor and MAPK proteins

β-caryophyllene (BCP), a natural sesquiterpene present in plants, is a selective agonist of cannabinoid receptor type-2 (CB2) of the endocannabinoid system. In this study, we have prepared an extract from Piper nigrum (black pepper) seeds using supercritical fluid extraction, standardized to contain 30% BCP (Viphyllin^TM ). The beneficial effects of prophylactic treatment with Viphyllin on cognitive functions were demonstrated in Scopolamine-induced dementia model mice. Male Swiss albino mice (25-30 g) were administered with Viphyllin (50 mg and 100 mg/kg body weight p.o.) or donepezil (1.60 mg/kg) for 14 days. Subsequently, cognitive deficits were induced by treating the animals intraperitoneally with Scopolamine (0.75 mg/kg). The cognitive behavior of mice was evaluated using a novel object recognition test (NORT) and Morris water maze (MWM) test. The brain homogenates were studied for biochemical parameters including cholinesterase activities and antioxidant status. Western blot analysis was performed to investigate the mechanism of action. Viphyllin dose dependently improved the recognition and spatial memory and cholinergic functions in Scop-treated mice. The extract was found protective against Scop-induced oxidative damage and histopathologic changes in the brain. At 100 mg/kg Viphyllin markedly reduced the proBDNF/mBDNF ratio (p < .05) and augmented the TrkB expression (p < .01). Viphyllin (100 mg/kg) was found to be neuroprotective by reducing the Scop-induced upregulation of p-JNK and p-p38 MAPK proteins, Bax/Bcl-2 ratio, and caspase activation in the brain. Viphyllin also exerted anti-inflammatory effects by downregulating Cox-2, TNF-α, and NOS-2 in Scop-induced mice (p < .05). To summarize, our data encourage Viphyllin as a functional ingredient/dietary supplement for brain health and cognition. PRACTICAL APPLICATIONS: Black pepper is a culinary spice having several medicinal attributes. Essential oils in the seeds of the plant give aroma and flavor to it. Here we have prepared an extract from the seeds of black pepper using supercritical fluid extraction, characterized for the presence of β-caryophyllene (not <30%). This research work further validates the neuroprotective mechanism of the extract in Scopolamine-induced cognitive impairment model mice. The findings from this study strongly suggest the beneficial neuroactive properties of black pepper seed extract having the presence of BCP, a CB2 receptor agonist. It can thus be used potentially as a functional food ingredient for cognition and brain function.

Loganin substantially ameliorates molecular deficits, pathologies and cognitive impairment in a mouse model of Alzheimer's disease

Alzheimer’s disease (AD) is the most common age-related neurodegenerative disease threatening the health of the elderly, but the available therapeutic and preventive drugs remain suboptimal. Loganin, an iridoid glycoside extracted from Cornus officinalis, is reported to have anti-inflammatory and memory-enhancing properties. This study is aimed to explore the influence of loganin on cognitive function in 3xTg-AD mice and the underlying mechanism associated with its neuroprotection. According to the results of behavioral tests, we found that administration of loganin could significantly alleviate anxiety behavior and improve memory deficits of 3xTg-AD mice. Furthermore, immunohistochemical analysis displayed that there were decreased Aβ deposition in the hippocampus and cortex of 3xTg-AD mice treated with loganin compared with the control mice. Importantly, the Aβ-related pathological change was mainly involved in altering APP expression and processing. And loganin was also found to reduce the levels of phosphorylated tau (i.e. pTau^S396 and pTau^S262) in 3xTg-AD mice. By performing 2D-DIGE combined with MALDI-TOF-MS/MS, we revealed 28 differentially expressed proteins in the 3xTg-AD mice treated with loganin compared with the control mice. Notably, 10 proteins largely involved in energy metabolism, synaptic proteins, inflammatory response, and ATP binding were simultaneously detected in 3xTg-AD mice compared to WT mice. The abnormal changes of energy metabolism (PAGM1 and ENO1), synaptic proteins (SYN2 and Cplx2), inflammatory response (1433Z) were verified by western blot. Overall, our study suggested that loganin could be used as a feasible candidate drug to ameliorate molecular deficits, pathologies and cognitive impairment for prevention and treatment of AD.

Histological and imunohistochemical alterations of hippocampus and prefrontal cortex in a rat model of Alzheimer like-disease with a preferential role of the flavonoid "hesperidin"

Alzheimer's disease (AD) is a chronic age-related neurodegenerative disease characterized by degeneration of the central cholinergic neurons, inflammation and oxidative stress in the basal forebrain, prefrontal cortex and hippocampus. Hesperidin (Hesp) is one of the flavonoids havinganti-inflammatory and anti-oxidative properties in some neurodegerative brain lesions. To investigate the possible neuroprotective role of Hespin an AD-like rat model induced experimentally by Scopolamine (Scop). Forty adult male Sprague Dawley rats were randomly allocated into four groups. Group I-(Control), group II-(Hesp) (supplemented orally with 100 mg/kg Hesp for 28 days), group III-(AD) (injected i.p with 1 mg/kg Scop for 9 days) and group IV-(Hesp/AD). At the end of the experiment, behavioral (Y-maze test) and biochemical analysis were carried out along with histological, immunohistochemical and morphometric studies of the hippocampus and prefrontal cortex. AD rats displayed memory impairment in the behavioural paradigm with a concomitant increase of serum TNF-α and IL-1β, while IL-10 decreased significantly. Also, there was a rise of amyloid beta-42 (Aβ-42), acetylcholinesterase (AChE) activity and malondialdehyde (MDA) together with a decrease of reduced glutathione (GSH) in hippocampal and prefrontal homogenate. In addition, sections of the hippocampus and prefrontal cortex revealed obvious histopathological changes, overexpression of p-Tau protein and glial fibrillary acidic protein (GFAP) with a decrease in the expression of synaptophysin (SYN). Contradictorily, pre-treatment with Hesp offset the spatial memory deficits, redox imbalance, Aβ-42 and AChE over activity as well as preserved the histological architecture and attenuated the raised p-Tau protein and GFAP while upregulated SYN immuoreactivity of AD rats. Collectively, our results highlight the potential mitigating role of Hesp in AD-like state in rats and this may presumably raise the possibility of its future implementation as a prophylactic remedy against AD in humans.

Oral Administration of Silibinin Ameliorates Cognitive Deficits of Parkinson's Disease Mouse Model by Restoring Mitochondrial Disorders in Hippocampus

Besides motor disorder, cognitive dysfunction is also common in Parkinson's disease (PD). Essentially no causal therapy for cognitive dysfunction of PD exists at present. In this study, a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD was used to analyze the neuroprotective potential of orally administered silibinin, a proverbial hepatoprotective flavonoid derived from the herb milk thistle (Silybum marianum). Results demonstrated that silibinin administration significantly attenuated MPTP-induced cognitive impairment in behavioral tests. Nissl staining results showed that MPTP injection significantly increases the loss of neurons in the hippocampus. However, these mice were protected by oral administration of silibinin, accompanying reduction in the cell apoptosis in the hippocampus. The hippocampal aggregates of α-synuclein (α-syn) appeared in MPTP-injected mice, but were significantly decreased by silibinin treatment. MPTP injection induced oxidative stress, as evidenced by increased malondialdehyde (MDA) and decreased superoxide dismutase (SOD). The oxidative stress was alleviated by silibinin treatment. Mitochondrial disorder including the decline of mitochondrial membrane potential (MMP) was another signature in the hippocampus of MPTP-treated mice, accompanying increased mitochondrial fission and decreased fusion. Silibinin administration restored these mitochondrial disorders, as expected for the protection against MPTP injury. These findings suggest that silibinin has a potential to be further developed as a therapeutic candidate for cognitive dysfunction in PD.

Sulforaphane enhances long-term potentiation and ameliorate scopolamine-induced memory impairment

Increases in human life expectancy have led to increases in the prevalence of senile dementia and neurodegenerative diseases. This is a major problem because there are no curative treatments for these diseases, and patients with unmanaged cognitive and neurodegenerative symptoms experience many social problems. Sulforaphane is a type of organosulfur compound known as an isothiocyanate. It is derived from glucoraphanin, a compound found in cruciferous vegetables such as broccoli, brussels sprouts, and cabbages, via an enzymatic reaction that is triggered by plant damage (e.g., chewing). Sulforaphane exhibits activity against cancer, inflammation, depression, and severe cardiac diseases. It can also alleviate oxidative stress and neural dysfunction in the brain. However, there is insufficient knowledge about the electrophysiological and behavioral basis of the effects of sulforaphane on learning and memory. Therefore, we evaluated whether acute sulforaphane administration affected long-term potentiation (LTP) in organotypic cultured rat hippocampal tissues. We also measured the effect of sulforaphane on the performance of three behavioral tests, the Y-maze test, the passive avoidance test, and the Morris water maze, which assess short-term memory, avoidance memory, and short and long-term spatial memory, respectively. We found that sulforaphane increased the total field excitatory postsynaptic potential (fEPSP) in a dose-dependent manner after high frequency stimulation and attenuated scopolamine-induced interference of the fEPSP in the hippocampal CA1 area. Sulforaphane also restored cognitive function and inhibited memory impairment as indicated by the alleviation of the negative neurological effects of scopolamine, i.e, a lowered ratio of spontaneous alternation in the Y-maze, a reduced step-through latency in the passive avoidance test, and an increased navigation time in the Morris water maze. These results indicate that sulforaphane can effectively prevent the attenuation of LTP and cognitive abilities induced by cholinergic and muscarinic receptor blockade. Further research is warranted to explore the potential therapeutic and prophylactic utility of sulforaphane for improving learning and memory, especially in those suffering from neurodegenerative disorders.

Traditional Korean herbal formulae, Yuk-Mi-Ji-Hwang-Tang, ameliorates impairment of hippocampal memory ability by chronic restraint stress of mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Yuk-Mi-Jihwang-Tang (YJT) has been popularly prescribed to treat aging related disorders over than hundreds of years in East Asia countries.

AIM OF THE STUDY

To investigate possible modulatory actions of YJT on chronic restraint stress (CRS)-induced neurodegeneration on hippocampus neuronal injuries.

MATERIALS AND METHODS

Mice were orally administered with YJT (100, 200, or 400 mg/kg) or ascorbic acid (100 mg/kg) before 4 h of stress for 28 days. Morris water maze task was completed from day 24th to 28th, and stress hormones and biochemical analyzes were measured.

RESULTS

Four weeks of the CRS abnormally affected memory impairments by measurement of escape latency and time spent in the target quadrant. Additionally, neurotransmitters were also drastically altered in serum or hippocampus protein levels by CRS. Gene expressions for 5-hydroxytryptamine (5-HT) receptor, 5-HT-transport, and tryptophan hydroxylase were also altered, whereas YJT led to normalize the above alterations. Additionally, YJT also beneficially worked on endogenous redox system as well as inflammatory reactions in the hippocampal neurons. We observed that hippocampal excitotoxicity was induced by CRS which were evidenced by depletion of phosphor-cAMP response element-binding protein, brain-derived neurotrophic factor, nuclear factor erythroid-2-related factor 2, heme oxygenase-1 and abnormally increases of acetylcholine esterase activities in hippocampus protein levels; however, YJT considerably improved the above pathological conditions.

CONCLUSIONS

Our findings supported YJT enhance memory function via regulation of hippocampal excitotoxicity-derived memory impairment, stress hormone, and endogenous redox, respectively.

Effect of Andrographis paniculata leaves extract on neurobehavioral and biochemical indices in scopolamine-induced amnesic rats

Andrographis paniculata is a medicinal herb that is used to treat various disease conditions due to its pharmacological properties. Thus, this study sought to assess the effect of A. paniculata extract on neurobehavioral and some biochemical parameters in scopolamine-induced amnesic rats. Thirty-five male rats were divided into seven groups and treated with aqueous extract of A. paniculata (50 and 500 mg/kg) and donepezil (5 mg/kg) for 14 days before administration of scopolamine. Behavioral studies (Morris water maze and Y-maze) were carried out to evaluate cognitive dysfunction in scopolamine-induced rats. Biochemical assays such as cholinesterases (AChE and BChE), monoamine oxidase (MAO), and purinergic activities were determined. Results revealed the presence of orientin, quercetin, caffeic acid, apigenin, and gallic acid in A. paniculata. Also, findings from this study showed that aqueous extract of A. paniculata had a modulatory effect on scopolamine-induced cognitive impairment and could be used in the management of memory loss. PRACTICAL APPLICATIONS: Aqueous extract of A. paniculata characterized revealed the presence of polyphenols which are antioxidants. The inhibitory activity possessed by A. paniculata on some enzymes linked to neurodegeneration could be due to the antioxidant activity. Given this, we recommend that results gotten from this study could be used to develop treatment therapy for neurodegeneration. However, in-depth studies should be carried out on the toxic effect of A. paniculata to ascertain a safe dose for treatment.

Isoorientin improves scopolamine-induced cognitive impairments by restoring the cholinergic system, antioxidant defense, and p-CREB/BDNF signaling in the hippocampus and frontal cortex

Isoorientin (ISO) is considered one of the most important flavonoids with various pharmacological effects such as antioxidant, anti-inflammatory, and anti-cancer activities. Despite these beneficial activities, the effects of ISO on learning and memory have not been investigated so far. The current study evaluated the memory-enhancing effects of ISO in a scopolamine-treated mouse model by using the Y-maze and passive avoidance tests. The results showed that ISO (5 and 10 mg/kg, p.o.) treatment significantly improved the cognitive impairments caused by scopolamine. Additionally, ISO significantly decreased scopolamine-induced acetylcholinesterase and thiobarbituric acid reactive substance activities in both the hippocampus and frontal cortex of mice. In addition, ISO significantly increased the levels of total superoxide dismutase induced by scopolamine in the hippocampus and frontal cortex. Moreover, Western blot results indicated that ISO reversed the decreases in expression of phosphorylated cAMP response element binding (CREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus and frontal cortex of scopolamine-treated mice. Thus, our results provide initial evidence that ISO ameliorates scopolamine-induced memory and cognitive impairments partly by restoring the cholinergic system, antioxidant defense, and p-CREB/BDNF signaling pathway, thereby exhibiting memory-enhancing activities.

Transneuronal Propagation of Pathologic α-Synuclein from the Gut to the Brain Models Parkinson's Disease

Analysis of human pathology led Braak to postulate that α-synuclein (α-syn) pathology could spread from the gut to brain via the vagus nerve. Here, we test this postulate by assessing α-synucleinopathy in the brain in a novel gut-to-brain α-syn transmission mouse model, where pathological α-syn preformed fibrils were injected into the duodenal and pyloric muscularis layer. Spread of pathologic α-syn in brain, as assessed by phosphorylation of serine 129 of α-syn, was observed first in the dorsal motor nucleus, then in caudal portions of the hindbrain, including the locus coeruleus, and much later in basolateral amygdala, dorsal raphe nucleus, and the substantia nigra pars compacta. Moreover, loss of dopaminergic neurons and motor and non-motor symptoms were observed in a similar temporal manner. Truncal vagotomy and α-syn deficiency prevented the gut-to-brain spread of α-synucleinopathy and associated neurodegeneration and behavioral deficits. This study supports the Braak hypothesis in the etiology of idiopathic Parkinson's disease (PD).

Active fraction combination from Liuwei Dihuang decoction (LW-AFC) ameliorates corticosterone-induced long-term potentiation (LTP) impairment in mice in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang decoction (LW), a classic formula in Traditional Chinese medicine (TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists of 6 herbs including Dihuang (prepared root of Rehmannia glutinosa (Gaertn.) DC.), Shanyao (rhizome of Dioscorea polystachya Turcz.), Shanzhuyu (fruit of Cornus officinalis Siebold & Zucc.), Mudanpi (root bark of Paeonia × suffruticosa Andrews), Zexie (rhizome of Alisma plantago-aquatica L.) and Fuling (scleorotia of Wolfiporia extensa (Peck) Ginns). LW-active fraction combination (LW-AFC) is extracted from LW, it is effective for the treatment of kidney yin deficiency in many animal models. Recent researches indicate that the "kidney deficiency" is related to a disturbance in the neuroendocrine immunomodulation (NIM) network, and glucocorticoids play an important role in kidney deficiency.

AIM OF THE STUDY

This study evaluated the effects of LW-AFC and the active fractions (polysaccharide, LWB-B; glycoside, LWD-b; oligosaccharide, CA-30) on corticosterone (Cort)-induced long-term potentiation (LTP) impairment in vivo.

MATERIALS AND METHODS

In this study, LTP was used to evaluate the synaptic plasticity. LW-AFC was orally administered for seven days. The active fractions were given by either chronic administration (i.g., i.p., 7 days) or single administration (i.c.v., i.g., i.p.). Cort was injected subcutaneously 1 h before the high-frequency stimulation (HFS) to induce LTP impairment. Moreover, in order to research on the possible effective pathways, an antibiotic cocktail and an immunosuppressant were also used.

RESULTS

Chronic administration (i.g.) of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Single administration (i.c.v., i.g., i.p.) of any of the active fractions had no effect on Cort-induced LTP impairment, while chronic administration (i.g., i.p.) of LWB-B or LWD-b showed positive effects against Cort. Interestingly, CA-30 only showed protective effects via i.g. administration, and there was little effect when CA-30 was administered i.p. In addition, when the intestinal microbiota was disrupted by application of the antibiotic cocktail, CA-30 showed little protective effects against Cort. The effects of LW-AFC were also abolished when the immune function was inhibited. In the hippocampal tissue, Cort treatment increased corticosterone and glutamate, and LW-AFC could inhibit the Cort-induced elevation of corticosterone and glutamate; there was little change in D-serine in Cort-treated animals, but LW-AFC could increase the D-serine levels.

CONCLUSION

LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Their protective effects are unlikely by a direct way, and immune modulation might be the common pathway. CA-30 could protect LTP from impairment via modulating the intestinal microbiota. Decreasing corticosterone and glutamate and increasing D-serine in the Cort-treated animals' hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC. Further study is needed to understand the underlying mechanisms.

Astaxanthin ameliorates scopolamine-induced spatial memory deficit via reduced cortical-striato-hippocampal oxidative stress

Alzheimer's disease is characterized by progressive disruption of cholinergic neurotransmission and impaired cognitive functions. In rodents, scopolamine has been used to induce cholinergic dysfunction resulting in cognitive impairments and an increment of oxidative stress in the brain. Here we tested whether oxidative stress can be attenuated via an antioxidant (astaxanthin) to rescue scopolamine-induced spatial memory. For this purpose, we administered either 0.9% saline (control), or scopolamine (SCP), or scopolamine plus astaxanthin (SCP + AST) to Swiss albino mice (ten weeks old; n = 20) for 28 consecutive days and subsequently examined animals' locomotor activity, spatial learning, and memory performance. The mice were then euthanized and prefrontal cortex (PFC), striatum (ST), hippocampus (HP), and liver tissues were assayed for antioxidant enzymes, glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and nitric oxide (NO). The SCP group exhibited impaired spatial learning and significantly altered levels of antioxidant enzymes and NO in the PFC, ST, and HP. In contrast, SCP + AST treatment did not cause spatial learning deficits. Furthermore, this condition also showed unaltered levels of SOD and NO in the ST and HP. Taken together, our results show that scopolamine may interrupt the striatal-hippocampal cholinergic activity resulting in impaired spatial memory. At the same time, these impairments are extinguished with astaxanthin by preventing oxidative damage in the striatal-hippocampal cholinergic neurons. Therefore, we suggest astaxanthin as a potential treatment to slow the onset or progression of cognitive dysfunctions that are elicited by abnormal cholinergic neurotransmission in Alzheimer's disease.

Health effects of kiwi wine on rats: an untargeted metabolic fingerprint study based on GC-MS/TOF

Kiwi wine is a popular fermentation product of kiwi fruit in Asian countries. To better understand the potential health effects of kiwi wine, an untargeted gas chromatography-mass spectrometer (GC-MS) approach was taken to assess the metabolic fingerprint of rats after dietary ingestion of kiwi wine. 7 differentially expressed endogenous metabolites from serum and 8 from urine were enriched in carbohydrate metabolism, amino acid metabolism pathway, fat metabolism and other metabolisms and selected from the KEGG. The above results showed that kiwi wine mainly led to a pronounced perturbation of energy metabolism (especially carbohydrate metabolism) during the consumption period. After stopping the supply of kiwi wine 30 days later, 6 and 3 endogenous metabolites from serum and urine respectively were screened and involved in a small part of carbohydrate related amino acid metabolism and fat metabolism, which indicated that the effect of kiwi wine sustained a lasting effect on energy metabolism, amino acid metabolism and lipid metabolism after stopping the supply. Thus, kiwi wine might have a positive function on health associated with the metabolism of its constituents. To the best of our knowledge, this study provides a nutrition field view for the development of the kiwi wine agricultural industry via an untargeted GC-MS metabolomic approach.

Loganetin protects against rhabdomyolysis-induced acute kidney injury by modulating the toll-like receptor 4 signalling pathway

BACKGROUND AND PURPOSE

Acute kidney injury (AKI) is a rapid renal dysfunctional disease, for which no effective drugs or therapies are available to improve prognosis. Loganetin is a natural product with unknown bioactivities. Here, we identified a new protective effect and mechanism of Loganetin in a mouse model of AKI induced by rhabdomyolysis.

EXPERIMENTAL APPROACH

AKI was induced using glycerol by i.m. injection in mice models. Thirty minutes and 24 and 48 hr after injection of glycerol, the mice received 2 and 18 mg·kg^-1 of Loganetin i.p. respectively. Then mice blood and kidney were collected for various biochemical and histopathological studies. Mechanistic studies on modulation of AKI by Loganetin were performed using HK-2 cells and Toll-like receptor 4 (TLR4) knockout mice.

KEY RESULTS

In the Loganetin treated group, kidney damage and mortality rate were declined, and blood urea nitrogen and serum creatinine were much lower. Loganetin prevented damage to the tubular structures induced by glycerol and decreased apoptotic cells at the corticomedullary junction. In HK-2 cells, Loganetin could inhibit NF-κB pathway and pro-apoptotic genes expression. However, TLR4 was silenced by a specific shRNA, and the inhibitory effect of Loganetin in HK-2 cells vanished. Loganetin also down-regulated the expression of inflammation factors by suppressing TLR4 activity.

CONCLUSION AND IMPLICATIONS

All the results suggested that TLR4 plays a critical role in AKI development, and Loganetin ameliorates AKI by inhibiting TLR4 activity and blocking the JNK/p38 pathway, which provides a new strategy for AKI treatment.

Effect of Nelumbo nucifera fruit on scopolamine induced memory deficits and motor coordination

From prehistoric time till today herbal medications are supposed to have neuroprotective effects both by inhibiting acetyl cholinesterase enzyme or antioxidant ability and are also affordable. Thus extensive studies are necessary to investigate the pharmacological effects of herbal plants. The goal of the present study was to ascertain the outcome of Nelumbo nucifera fruit (NNF) on scopolamine induced amnestic rats along with motor coordination in mice in order to explore its pharmacological use in disorders like Alzheimer's disease (AD). The effect of NNF on learning and memory was assessed by Morris water maze test using 35 Wister rats weighing 200-230 g evenly divided in to five groups. While motor coordination was assessed using Rot rod test, 35 male locally bred albino mice weighing 20-25 g were equally divided in to five groups. Group I was kept as control (10 ml/kg gum tragacanth). Group II, III and IV were labeled as treated groups (NNF 50, 100 and 200 mg/kg). Group V served as reference group (piracetam 200 mg/kg). All drugs were given by oral route as a single dose for 15 days in both experiments to rats and mice, however scopolamine (1 mg/kg IP) was used in Morris water maze test 40 min after the administration of drugs to rats for the induction of amnesia. In Morris water maze test, N. nucifera fruit caused highly significant and significant decrease in escape latency in the amnestic rats at 200 and 100 mg/kg as compared to control. In Rota rod test, N. nucifera fruit did not exhibit any notable changes in the riding time at any dose as compared to control. N. nucifera fruit have demonstrated ameliorating effects on memory without affecting muscle coordination. Hence NNF seems to have great potential for therapeutic application in memory disorders, such as AD which may be due to its ability to enhance cholinergic neurotransmission and exerting antioxidant effect and thus encourage more preclinical and clinical trials in this field.

Loganin prevents BV-2 microglia cells from Aβ1-42 -induced inflammation via regulating TLR4/TRAF6/NF-κB axis

Neuroinflammation is closely related with the pathogenesis and progress of neurodegenerative diseases including Alzheimer's disease (AD). Loganin, an iridoid glycoside obtained from traditional Chinese medicine Cornus officinalis, has properties of inhibiting inflammation and improving memory. The present study was aimed to investigate effects of loganin on Aβ-induced inflammation and to explore the underlying mechanisms. BV-2 microglia cells were stimulated with 10 µM Aβ_1-42 for 24 h to induce inflammatory damage. According to results of CCK-8 assay, the doses of loganin in present work were 10 and 30 µM. We found that treatment with loganin could inhibit Aβ_1-42 -induced microglia activation. Furthermore, loganin treatment prevented the over-production of Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Macrophage Chemotactic Protein 1(MCP-1), Nitric oxide (NO), Prostaglandin E2 (PGE2) and the up-regulation of inducible nitric oxide synthase (iNOS) and Cyclooxygenase 2 (COX-2) in Aβ_1-42 -stimulated BV-2 cells. Results from Western blots demonstrated that loganin inhibited Aβ_1-42 -induced elevation in Toll-like receptor 4 (TLR4), Myeloid Differentiation Factor 88 (MyD88) and TNF receptor-associated factor 6 (TRAF6). Loganin treatment also attenuated the increased phosphorylation level of IRAK4 caused by Aβ_1-42 . Additionally, loganin alleviated nuclear translocation of NF-κB p65 subunit in Aβ_1-42 -stimulated BV-2 cells, and this phenomenon could be reversed by TLR4 agonist LPS. Further, the anti-inflammatory effects of loganin were attenuated when TLR4 signaling pathway was re-activated by LPS. Taken together, our data indicated that loganin could attenuate inflammatory response induced by Aβ in BV-2 microglia cells, partially through deactivating the TLR4/TRAF6/NF-κB axis.

Scabiosa Genus: A Rich Source of Bioactive Metabolites

The genus Scabiosa (family Caprifoliaceae) is considered large (618 scientific plant names of species) although only 62 have accepted Latin binominal names. The majority of the Scabiosa species are widely distributed in the Mediterranean region and some Scabiosa species are used in traditional medicine systems. For instance, Scabiosa columbaria L. is used traditionally against diphtheria while S. comosa Fisch. Ex Roem. and Schult. is used in Mongolian and Tibetan traditional medical settings to treat liver diseases. The richness of Scabiosa species in secondary metabolites such as iridoids, flavonoids and pentacyclic triterpenoids may contribute to its use in folk medicine. Details on the most recent and relevant pharmacological in vivo studies on the bioactive secondary metabolites isolated from Scabiosa species will be summarized and thoroughly discussed.

Antioxidant Effects of Bioactive Compounds Isolated from Pressurized Steam-Treated Corni Fructus and Their Protective Effects Against UVB-Irradiated HS68 Cells

This study evaluated the antioxidant and protective effects of bioactive compounds isolated from pressurized steam-treated Corni Fructus (PSC). We had previously tested the protective effects of the furan fraction containing 5-hydroxymethylfurfural (5-HMF), polyphenol fraction containing gallic acid, and iridoid glycoside fraction containing morroniside and loganin. We measured the potency of antioxidant activities of the bioactive compounds isolated from PSC via oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. One fraction in particular (named F-2) not only contained high amounts of phenolics but also had potent antioxidant activities. The protective effects of F-2 were evaluated by measuring the levels of the collagen-degrading enzyme, matrix metalloproteinase-1 (MMP-1), and the marker of collagen biosynthesis, procollagen type I C-peptide (PIP), in UVB-treated HS68 fibroblasts. MMP-1 levels decreased in an F-2 concentration-dependent manner, and PIP secretion from the cultured HS68 cells was significantly higher than that from the UVB-irradiated cultures alone. Further, F-2 attenuated UVB-induced MMP-1 and ameliorated UVB-downregulated collagen type I alpha 1 mRNA expression in HS68 cells. Therefore, F-2 isolated from PSC is a good candidate for the prevention of skin damage from free radicals in various skin conditions.

Amelioration of Cognitive Deficit by Embelin in a Scopolamine-Induced Alzheimer's Disease-Like Condition in a Rat Model

Embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) is one of the active components (2.3%) found in Embelia ribes Burm fruits. As determined via in vitro AChE inhibition assay, embelin can inhibit the acetylcholinesterase enzyme. Therefore, embelin can be utilized as a therapeutic compound, after further screening has been conducted for its use in the treatment of Alzheimer's disease (AD). In this study, the nootropic and anti-amnesic effects of embelin on scopolamine-induced amnesia in rats were evaluated. Rats were treated once daily with embelin (0.3 mg/kg, 0.6 mg/kg, 1.2 mg/kg) and donepezil (1 mg/kg) intraperitoneally (i.p.) for 17 days. During the final 9 days of treatment, a daily injection of scopolamine (1 mg/kg) was administered to induce cognitive deficits. Besides that, behavioral analysis was carried out to assess the rats' learning and memory functions. Meanwhile, hippocampal tissues were extracted for gene expression, neurotransmitter, and immunocytochemistry studies. Embelin was found to significantly improve the recognition index and memory retention in the novel object recognition (NOR) and elevated plus maze (EPM) tests, respectively. Furthermore, embelin at certain doses (0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg) significantly exhibited a memory-enhancing effect in the absence of scopolamine, besides improving the recognition index when challenged with chronic scopolamine treatment. Moreover, in the EPM test, embelin treated rats (0.6 mg/kg) showed an increase in inflection ratio in nootropic activity. However, the increase was not significant in chronic scopolamine model. In addition, embelin contributed toward the elevated expression of BDNF, CREB1, and scavengers enzymes (SOD1 and CAT) mRNA levels. Next, pretreatment of rats with embelin mitigated scopolamine-induced neurochemical and histological changes in a manner comparable to donepezil. These research findings suggest that embelin is a nootropic compound, which also possesses an anti-amnesic ability that is displayed against scopolamine-induced memory impairment in rats. Hence, embelin could be a promising compound to treat AD.

Green leafy vegetables from two Solanum spp. (Solanum nigrum L and Solanum macrocarpon L) ameliorate scopolamine-induced cognitive and neurochemical impairments in rats

This study examined the modulatory effect of Black nightshade (Solanum nigrum L) and African eggplant (Solanum macrocarpon L) leaves on cognitive function, antioxidant status, and activities of critical enzymes of monoaminergic and cholinergic systems of neurotransmission in scopolamine-administered rats. Cognitive impairment was induced in albino rats pretreated with dietary inclusions of Black nightshade (BN) and African eggplant (AE) leaves by single administration (i.p.) of scopolamine (2 mg/kg body weight). Prior to termination of the experiment, the rats were subjected to spontaneous alternation (Y-maze) test to assess their spatial working memory. Thereafter, activities of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), arginase, and antioxidant enzymes (catalase, SOD, and GST) of rat brain homogenate were determined. Also, the malondialdehyde (MDA), nitrite, and GSH contents of the homogenate were determined. The results showed that pretreatment with dietary inclusions of AE and BN significantly reversed the impairment in the rats' spatial working memory induced by scopolamine. Similarly, elevations in activities of AChE, BChE, and MAO induced by scopolamine were significantly reversed in rats pretreated with dietary inclusions of AE and BN. In addition, impaired antioxidant status induced by scopolamine was reversed by pretreatment with dietary inclusions of AE and BN. This study has shown that dietary inclusions of AE and BN could protect against cognitive and neurochemical impairments induced by scopolamine, and hence, these vegetables could be used as a source of functional foods and nutraceuticals for the prevention and management of cognitive impairments associated diseases such as Alzheimer's disease.

Iridoids and Other Monoterpenes in the Alzheimer's Brain: Recent Development and Future Prospects

Iridoids are a class of monoterpenoid compounds constructed from 10-carbon skeleton of isoprene building units. These compounds in their aglycones and glycosylated forms exist in nature to contribute to mechanisms related to plant defenses and diverse plant-animal interactions. Recent studies have also shown that iridoids and other structurally related monoterpenes display a vast array of pharmacological effects that make them potential modulators of the Alzheimer’s disease (AD). This review critically evaluates the therapeutic potential of these natural products by assessing key in vitro and in vivo data published in the scientific literature. Mechanistic approach of scrutiny addressing their effects in the Alzheimer’s brain including the τ-protein phosphorylation signaling, amyloid beta (Aβ) formation, aggregation, toxicity and clearance along with various effects from antioxidant to antiinflammatory mechanisms are discussed. The drug likeness of these compounds and future prospects to consider in their development as potential leads are addressed.

Botany, Phytochemistry, Pharmacology and Toxicity of Strychnos nux-vomica L.: A Review

Strychnos nux-vomica L. belongs to the genus Strychnos of the family Loganiaceae and grows in Sri Lanka, India and Australia. The traditional medicinal component is its seed, called Nux vomica. This study provides a relevant and comprehensive review of S. nux-vomica L., including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology, thus providing a foundation for future studies. Up to the present day, over 84 compounds, including alkaloids, iridoid glycosides, flavonoid glycosides, triterpenoids, steroids and organic acids, among others, have been isolated and identified from S. nux-vomica. These compounds possess an array of biological activities, including effects on the nervous system, analgesic and anti-inflammatory actions, antitumor effects, inhibition of the growth of pathogenic microorganisms and regulation of immune function. Furthermore, toxicity and detoxification methods are preliminarily discussed toward the end of this review. In further research on S. nux-vomica, bioactivity-guided isolation strategies should be emphasized. Its antitumor effects should be investigated further and in vivo animal experiments should be performed alongside in vitro testing. The pharmacological activity and toxicology of strychnine [Formula: see text]-oxide and brucine [Formula: see text]-oxide should be studied to explore the detoxification mechanism associated with processing more deeply.

Resveratrol, pterostilbene, and dementia

Resveratrol is a natural phytoestrogen with neuroprotective properties. Polyphenolic compounds including resveratrol exert in vitro antioxidant, anti-inflammatory, and antiamyloid effects. Resveratrol and its derivative pterostilbene are able to cross the blood-brain barrier and to influence brain activity. The present short review summarizes the available evidence regarding the effects of these polyphenols on pathology and cognition in animal models and human subjects with dementia. Numerous investigations in cellular and mammalian models have associated resveratrol and pterostilbene with protection against dementia syndromes such as Alzheimer's disease (AD) and vascular dementia. The neuroprotective activity of resveratrol and pterostilbene demonstrated in in vitro and in vivo studies suggests a promising role for these compounds in the prevention and treatment of dementia. In comparison to resveratrol, pterostilbene appears to be more effective in combatting brain changes associated with aging. This may be attributed to the more lipophilic nature of pterostilbene with its two methoxyl groups compared with the two hydroxyl groups of resveratrol. The findings of available intervention trials of resveratrol in individuals with mild cognitive impairment or AD do not provide evidence of neuroprotective or therapeutic effects. Future clinical trials should be conducted with long-term exposure to preparations of resveratrol and pterostilbene with high bioavailability. © 2017 BioFactors, 44(1):83-90, 2018.

The Requirement of L-Type Voltage-Dependent Calcium Channel (L-VDCC) in the Rapid-Acting Antidepressant-Like Effects of Scopolamine in Mice

BACKGROUND

Previous studies have shown that a low dose of scopolamine produces rapid-acting antidepressant-like actions in rodents. Understanding the mechanisms underlying this effect and the dose-dependent variations of drug responses remains an important task. L-type voltage-dependent calcium channels were found to mediate rapid-acting antidepressant effects of certain medications (e.g., ketamine). Therefore, it is of great interest to determine the involvement of L-type voltage-dependent calcium channels in the action of scopolamine.

METHODS

Herein, we investigated the mechanisms underlying behavioral responses to various doses of scopolamine in mice to clarify the involvement of L-type voltage-dependent calcium channels in its modes of action. Open field test, novel object recognition test, and forced swimming test were performed on mice administered varied doses of scopolamine (0.025, 0.05, 0.1, 1, and 3 mg/kg, i.p.) alone or combined with L-type voltage-dependent calcium channel blocker verapamil (5 mg/kg, i.p.). Then, the changes in brain-derived neurotrophic factor and neuropeptide VGF (nonacronymic) levels in the hippocampus and prefrontal cortex of these mice were analyzed.

RESULTS

Low doses of scopolamine (0.025 and 0.05 mg/kg) produced significant antidepressant-like effects in the forced swimming test, while higher doses (1 and 3 mg/kg) resulted in significant memory deficits and depressive-like behaviors. Moreover, the behavioral changes in responses to various doses may be related to the upregulation (0.025 and 0.05 mg/kg) and downregulation (1 and 3 mg/kg) of brain-derived neurotrophic factor and VGF in the hippocampus and prefrontal cortex in mice. We further found that the rapid-acting antidepressant-like effects and the upregulation on brain-derived neurotrophic factor and VGF produced by a low dose of scopolamine (0.025 mg/kg) were completely blocked by verapamil.

CONCLUSIONS

These results indicate that L-type voltage-dependent calcium channels are likely involved in the behavioral changes in response to various doses of scopolamine through the regulation of brain-derived neurotrophic factor and VGF levels.

Variation of loganin content in Cornus officinalis fruits at different extraction conditions and maturation stages

Efficient preparation of loganin from Cornus officinalis fruits was investigated. First, effect of extraction conditions on loganin yield was measured. The loganin content in C. officinalis extract was greatly affected by ethanol concentration and extraction time whereas extraction temperature exerted relatively little effect. Response surface methodology with Box-Behnken design suggested optimized extraction condition for maximum loganin yield as ethanol concentration, 32.0%; temperature 46.2 °C and extraction time, 46.7 min, which yielded 10.4 μg loganin/mg dried fruit. Next, the effect of maturation stage of C. officinalis fruits on loganin content was investigated. The loganin content in the extract of C. officinalis fruits was decreased as the maturation process. The loganin content in the unripe fruits was 18.0 μg/mg extract whereas reduced to 13.3 μg/mg extract for ripe fruits. Taken together, our present study suggested the importance of extraction condition and maturation stages for efficient preparation of loganin from C. officinalis fruits.

Neurochemical and neuropharmacological characterization of ASP2905, a novel potent selective inhibitor of the potassium channel KCNH3

KCNH3 (BEC1) is a member of the ether-à-go-go (KCNH) family of voltage-gated K⁺ channels. The aim of this study was to determine the pharmacological profiles in vitro and in vivo of a KCNH3 inhibitor N-(4-fluorophenyl)-N'-phenyl-N''-(pyrimidin-2-ylmethyl)-1,3,5-triazine-2,4,6-triamine (ASP2905). We analyzed the effects of ASP2905 on channel activity in vitro and its neuropharmacological properties in young and aged rats as well as in mice. ASP2905 potently inhibited potassium currents in CHO cells expressing KCNH3 (IC₅₀ = 9.0nM). In contrast, ASP2905 (≤ 10μM) minimally bound with low affinities to 55 transmembrane proteins. ASP2905 (0.1µM, 1µM) decreased the frequency of spontaneous inhibitory postsynaptic currents in cultured rat hippocampal neurons. In mice, ASP2905 reversed the disruption of spontaneous alternation behavior induced by MK-801 and scopolamine (minimum effective dose of ASP2905: 0.0625mg/kg, po). ASP2905 ameliorated the cognitive deficits of aged rats in step-through passive avoidance (0.0313 and 0.0625mg/kg, po) and Morris water-maze tasks (0.01mg/kg, po) and effectively penetrated the brain. The mean plasma and brain concentrations of ASP2905 reached their maxima (C_max = 0.399ng/ml and 1.77ng/g, respectively) 1h after a single oral administration and then decreased (t_1/2 = 1.5-1.6h) (brain plasma ratio = 2.7-4.9). The present study suggests that ASP2905 is a selective, orally administered inhibitor of KCNH3, which can enhance cognitive performance.

Unexpected Neuroprotective Effects of Loganin on 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Neurotoxicity and Cell Death in Zebrafish

1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP), which induces the pathological characteristics of Parkinson's disease in rodents, also specifically targets dopaminergic neurons in zebrafish embryos and larvae. Loganin, a traditional Chinese drug, was reported to regulate immune function and possess anti-inflammatory and anti-shock effects. Here, we investigate the role of loganin in MPTP-induced Parkinson-like abnormalities in zebrafish. MPTP treatment-induced abnormal development, in larvae, such as pericardium edema, increased yolk color, yolk sac edema, and retarded yolk sac resorption, as well as defects in brain development. Loganin could block MPTP-induced defects, with little toxicity to the eggs. Results of whole mount in situ hybridization showed loganin prevented the loss of both dopaminergic neurons and locomotor activity, exhibited by larvae treated with MPTP. In addition, loganin significantly rescued MPTP-induced neurotoxicity on PC12 cells, possibly through the suppression of PI3K/Akt/mTOR axis and JNK signaling pathways. In conclusion, loganin blocks MPTP-induced neurotoxicity and abnormal development in zebrafish. J. Cell. Biochem. 118: 615-628, 2017. © 2016 Wiley Periodicals, Inc.

A review on medicinal uses, analytical techniques and pharmacological activities of Strychnos nux-vomica Linn.: A concise report

The purpose of this review is to provide comprehensive and relevant information on the utilization and pharmacological activities of Strychnos nux-vomica Linn. (Loganiaceae), used for the treatment of various diseases. Strychnos nux-vomica is an evergreen tree native to Southeast Asia and its dried seeds are used for the treatment of neurodisorders, arthritis and vomiting. The different use of this plant as herbal remedy in Chinese medicine is also reported in the literature. Strychnine and brucine are major pharmacologically active phytoconstituents of Strychnos nux-vomica, which are central nervous stimulant, but also found to be poisonous at high dosage. Owing to its diversity of phytoconstituents, it is used for treatment of various disorders. Pharmacologically it has been validated for its effect on inflammation, microbial infections, gastrointestinal problem, nervous system, bones cells, cardiovascular systems, cancer and blood glucose level. It also has antioxidant activity and antifeedant activity. Informations about Strychnos nux-vomica, compiled in the present review article could be useful to the researchers for the scientific validation of its traditional claim in the future.

Loganin enhances long-term potentiation and recovers scopolamine-induced learning and memory impairments

Although the incidence rate of dementia is rapidly growing in the aged population, therapeutic and preventive reagents are still suboptimal. Various model systems are used for the development of such reagents in which scopolamine is one of the favorable pharmacological tools widely applied. Loganin is a major iridoid glycoside obtained from Corni fructus (Cornusofficinalis et Zucc) and demonstrated to have anti-inflammatory, anti-tumor and osteoporosis prevention effects. It has also been found to attenuate Aβ-induced inflammatory reactions and ameliorate memory deficits induced by scopolamine. However, there has been limited information available on how loganin affects learning and memory both electrophysiologically and behaviorally. To assess its effect on learning and memory, we investigated the influence of acute loganin administration on long-term potentiation (LTP) using organotypic cultured hippocampal tissues. In addition, we measured the effects of loganin on the behavior performance related to avoidance memory, short-term spatial navigation memory and long-term spatial learning and memory in the passive avoidance, Y-maze, and Morris water maze learning paradigms, respectively. Loganin dose-dependently increased the total activity of fEPSP after high frequency stimulation and attenuated scopolamine-induced blockade of fEPSP in the hippocampal CA1 area. In accordance with these findings, loganin behaviorally attenuated scopolamine-induced shortening of step-through latency in the passive avoidance test, reduced the percent alternation in the Y-maze, and increased memory retention in the Morris water maze test. These results indicate that loganin can effectively block cholinergic muscarinic receptor blockade -induced deterioration of LTP and memory related behavioral performance. Based on these findings, loganin may aid in the prevention and treatment of Alzheimer's disease and learning and memory-deficit disorders in the future.

Anti-cholinesterases and memory improving effects of Vietnamese Xylia xylocarpa

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia among the elderly and is characterized by loss of memory and other cognitive functions. An increase in AChE (a key enzyme in the cholinergic nervous system) levels around β-amyloid plaques and neurofibrillary tangles is a common feature of AD neuropathology. Amnesic effects of scopolamine (acetylcholine receptor antagonist) can be investigated in various behavioral tests such as Morris water maze, object recognition, Y-maze, and passive avoidance. In the scope of this paper, we report the anti-AChE, anti-BChE properties of the isolated compound and the in vivo effects of the methanolic extract of Xylia xylocarpa (MEXX) on scopolamine-induced memory deficit.

RESULTS

In further phytochemistry study, a new hopan-type triterpenoid, (3β)-hopan-3-ol-28,22-olide (1), together with twenty known compounds were isolated (2-21). Compound 1, 2, 4, 5, 7-9, and 11-13 exhibited potent acetylcholinesterase (AChE) inhibitory activity in a concentration-dependent manner with IC50 values ranging from 54.4 to 94.6 μM. Compound 13 was also shown anti-butyrylcholinesterase (BChE) activity with an IC50 value of 42.7 μM. The Morris water Y-maze, Y-maze, and object recognition test were also carried out.

CONCLUSIONS

It is noteworthy that MEXX is effective when administered orally to mice, experimental results are consistent with the traditional use of this medicinal plant species.

You-Gui pills promote nerve regeneration by regulating netrin1, DCC and Rho family GTPases RhoA, Racl, Cdc42 in C57BL/6 mice with experimental autoimmune encephalomyelitis

ETHNOPHARMACOLOGICAL RELEVANCE

You-Gui pills (YGPs) are an effective traditional Chinese formula being used clinically for the treatment of multiple sclerosis (MS). Previous studies demonstrated that YGPs exerted the potent neuroprotective effects in murine models of experimental autoimmune encephalomyelitis (EAE), which is an equivalent animal model for multiple sclerosis (MS). However, the mechanism of YGPs functions remained unclear.

AIM OF THIS STUDY

The aim of this study was to evaluate the therapeutic effect of YGPs in MOG35-55-induced EAE mice and to further elucidate the underlying molecular mechanism.

METHODS

Female C57BL/6 mice were divided into six groups, including the non-treated EAE model, prednisone acetate- and 1.2, 2.4 or 4.8g/kg YGPs-treated EAE groups, and a normal control group. The EAE model was established by injecting the mice subcutaneously with MOG35-55 antigen. The body weights were measured and the neurological functions were scored in each group. The pathology and morphology of the brain and spinal cord was examined. The expression of MAP-2 was detected by immunofluorescent staining. The levels of netrin1, DCC, RhoA, Rac1, and Cdc42 were assayed by immunohistochemistry, qRT-PCR and Western blot on day 40 post-immunization (PI).

RESULTS

YGPs treatments significantly reduced neurological function scores in EAE mice, where the inflammatory infiltration was reduced and the axon and myelin damage in both brain and spinal cord was alleviated. In the brain and spinal cord tissues, YGPs increased the expression of neuronal factors MAP-2, netrin1 and DCC. The expression of Rac1 and Cdc42 were increased, while RhoA was reduced following YGPs treatments.

CONCLUSION

Our results demonstrated that YGPs exhibited a neuroprotective effect on promoting nerve regeneration at the brain and spinal cord in EAE mice induced by MOG35-55. Netrin1, DCC and the Rho family GTPases of RhoA, Racl, Cdc42 were involved in mediating the effects of YGPs on nerve regeneration.

Neuroprotective effect of loganin against Aβ25-35-induced injury via the NF-κB-dependent signaling pathway in PC12 cells

Amyloid-beta (Aβ) protein, the main constituent of senile plaques, is believed to play a pivotal role in the pathogenesis of Alzheimer's disease (AD). AD is closely associated with inflammatory reactions which are considered to be responses to Aβ deposition. The present study investigated the effect of loganin on Aβ25-35-induced inflammatory damage and the underlying molecular mechanism of its neuroprotective action. Loganin predominantly prevented Aβ25-35-stimulated cell death through suppressing ROS generation, and attenuating apoptosis by inhibiting caspase-3 activity and regulating cell cycle. Furthermore, loganin suppressed the level of TNF-α and protein expression of iNOS and COX-2 in Aβ25-35-injured PC12 cells. These inhibitions appeared to correlate with the suppression of NF-κB activation by loganin, as pre-treating cells with loganin blocked the translocation of NF-κB into the nuclear compartment and degradation of the inhibitory subunit IκB. Loganin substantially inhibited phosphorylation of MAPKs including ERK1/2, p38 and JNK, which are closely related to regulation of NF-κB activation. Taken together, the results implied that loganin attenuated neuroinflammatory responses through the inactivation of NF-κB by NF-κB dependent inflammatory pathways and phosphorylation of MAPK in Aβ25-35-induced PC12 cells.