Dendropanax morbifera Léveille extract ameliorates cadmium-induced impairment in memory and hippocampal neurogenesis in rats

Maternal supplementation with Dipteryx alata Vog. modulates fecal microbiota diversity, accelerates reflex ontogeny, and improves non-associative and spatial memory in the offspring of rats

Maternal diet plays a crucial role in offspring development, directly affecting neural development and gut microbiota composition. This study aimed to assess if baru almond and oil (Dipteryx alata Vog.) could modulate intestinal microbiota, brain fatty acid profile, and enhance memory in offspring of rats treated during early life stages. Three groups were formed: Control- received distilled water by gavage; Oil- received 2000 mg/kg of baru oil, and Almond - received 2000 mg/kg of baru almond. Somatic development and reflex ontogenesis were evaluated in offspring during the first 21 days. In adolescence and adulthood, memory was tested using Open Field Habituation, Object Recognition, and Morris Water Maze. Brain histology and fatty acid were measured, and fecal microbiota analysis was performed. Both almond and oil groups showed increased PUFAs in breast milk and brains, accelerated reflex ontogeny, improved somatic development and better performance in the memory tests in both life stages (p < 0.05). Supplementation enhanced fecal microbiota abundance associated with neuroprotective effects. The almond group showed a 29 % increase in Eubacterium, Candidates-Arthromitus, Collinsella, and Christensenellaceae-R-7. Both oil and almond groups had higher Blautia and Clostridia-UCG-014 compared to controls. The oil group had about 10 % more Ruminococcus, UCG-005, Acetatifactor, Negativibacillus, and Lachnospiraceae-ND3007 than the others. With the present data, we can observe the safety of baru consumption by pregnant and lactating rats and verify its effects on modulating the microbiota, inducing adequate development of the offspring's nervous system, contributing to anticipated reflex maturation and improving memory.

Adolescent co-exposure to environmental cadmium and high-fat diet induces cognitive decline via Larp7 m6A-mediated SIRT6 inhibition

The effects and underlying mechanisms of adolescent exposure to combined environmental hazards on cognitive function remain unclear. Here, using a combined exposure model, we found significant cognitive decline, hippocampal neuronal damage, and neuronal senescence in mice exposed to cadmium (Cd) and high-fat diet (HFD) during adolescence. Furthermore, we observed a significant downregulation of Sirtuin 6 (SIRT6) expression in the hippocampi of co-exposed mice. UBCS039, a specific SIRT6 activator, markedly reversed the above adverse effects. Further investigation revealed that co-exposure obviously reduced the levels of La ribonucleoprotein 7 (LARP7), disrupted the interaction between LARP7 and SIRT6, ultimately decreasing SIRT6 expression in mouse hippocampal neuronal cells. Overexpression of Larp7 reversed the combined exposure-induced SIRT6 decrease and senescence in mouse hippocampal neuronal cells. Additionally, the results showed notably elevated levels of Larp7 m6A and YTH domain family protein 2 (YTHDF2) in mouse hippocampal neuronal cells treated with the combined hazards. Ythdf2 short interfering RNA, RNA immunoprecipitation, and RNA stability assays further demonstrated that YTHDF2 mediated the degradation of Larp7 mRNA under combined exposure. Collectively, adolescent co-exposure to Cd and HFD causes hippocampal senescence and cognitive decline in mice by inhibiting LARP7-mediated SIRT6 expression in an m6A-dependent manner.

The Neuroprotective Effects of Dendropanax morbifera Water Extract on Scopolamine-Induced Memory Impairment in Mice

This study investigated the neuroprotective effects of Dendropanax morbifera leaves and stems (DMLS) water extract on scopolamine (SCO)-induced memory impairment in mice. First, we conducted experiments to determine the protective effect of DMLS on neuronal cells. Treatment with DMLS showed a significant protective effect against neurotoxicity induced by Aβ(25-35) or H2O2. After confirming the neuroprotective effects of DMLS, we conducted animal studies. We administered DMLS orally at concentrations of 125, 250, and 375 mg/kg for 3 weeks. In the Y-maze test, SCO decreased spontaneous alternation, but treatment with DMLS or donepezil increased spontaneous alternation. In the Morris water-maze test, the SCO-treated group showed increased platform reach time and decreased swim time on the target platform. The passive avoidance task found that DMLS ingestion increased the recognition index in short-term memory. Furthermore, memory impairment induced by SCO reduced the ability to recognize novel objects. In the Novel Object Recognition test, recognition improved with DMLS or donepezil treatment. In the mouse brain, except for the cerebellum, acetylcholinesterase activity increased in the SCO group and decreased in the DMLS and donepezil groups. We measured catalase and malondialdehyde, which are indicators of antioxidant effectiveness, and found that oxidative stress increased with SCO but was mitigated by DMLS or donepezil treatment. Thus, our findings suggest that ingestion of DMLS restored memory impairment by protecting neuronal cells from Aβ(25-35) or H2O2-induced neurotoxicity, and by reducing oxidative stress.

Environmental exposure of the general population to cadmium as a risk factor of the damage to the nervous system: A critical review of current data

Nowadays, more and more attention has been focused on the risk of the neurotoxic action of cadmium (Cd) under environmental exposure. Due to the growing incidence of nervous system diseases, including neurodegenerative changes, and suggested involvement of Cd in their aetiopathogenesis, this review aimed to discuss critically this element neurotoxicity. Attempts have been made to recognize at which concentrations in the blood and urine Cd may increase the risk of damage to the nervous system and compare it to the risk of injury of other organs and systems. The performed overview of the available literature shows that Cd may have an unfavourable impact on the human's nervous system at the concentration >0.8 μg Cd/L in the urine and >0.6 μg Cd/L in the blood. Because such concentrations are currently noted in the general population of industrialized countries, it can be concluded that environmental exposure to this xenobiotic may create a risk of damage to the nervous system and be involved in the aetiopathogenesis of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as worsening cognitive and behavioural functions. The potential mechanism of Cd neurotoxicity consists in inducing oxidative stress, disrupting the activity of enzymes essential to the proper functioning of the nervous system and destroying the homoeostasis of bioelements in the brain. Thus, further studies are necessary to recognize accurately both the risk of nervous system damage in the general population due to environmental exposure to Cd and the mechanism of this action.

Effect of methylmercury on fetal neurobehavioral development: an overview of the possible mechanisms of toxicity and the neuroprotective effect of phytochemicals

Methylmercury (MeHg) is a global environmental pollutant with neurotoxic effects. Exposure to MeHg via consumption of seafood and fish can severely impact fetal neurobehavioral development even when MeHg levels in maternal blood are as low as about 5 μg/L, which the mother tolerates well. Persistent motor dysfunctions and cognitive deficits may result from trans-placental exposure. The present review summarizes current knowledge on the mechanisms of MeHg toxicity during the period of nervous system development. Although cerebellar Purkinje cells are MeHg targets, the actions of MeHg on thiol components in the neuronal cytoskeleton as well as on mitochondrial enzymes and induction of disturbances of glutamate signaling can impair extra-cerebellar functions, also at levels well tolerated by adult individuals. Numerous herbal substances possess neuroprotective effects, predominantly represented by natural polyphenolic molecules that might be utilized to develop natural drugs to alleviate neurotoxicity symptoms caused by MeHg or other Hg compounds.

Effect of zinc and copper ions on cadmium-induced toxicity in rat cultured cortical neurons

BACKGROUND

Cadmium is a highly toxic heavy metal that is capable of accumulating in the body and causing neurodegeneration. However, the effect of other trace elements on Cd²⁺ toxicity is currently poorly understood. The aim of this work was to study the effect of Zn²⁺ and Cu²⁺ ions on cadmium-induced death of neurons in the cerebral cortex.

METHODS

The work was performed on rat cortical primary cultures. The MTT test was used to determine the cytotoxicity effects. Analysis of intracellular Ca²⁺ concentration was assessed by the Fluo-4 AM calcium indicator that exhibit an increase in fluorescence upon binding Ca²⁺. MitoSOX Red (mitochondrial superoxide indicator) was used to measuring mitochondrial ROS content in live cells.

RESULTS

In this article, we show that the administration of CdCl₂ (0.005-0.02 mM) for 48 h induced an increase in dose-dependent death rate of cultured cortical neurons. Mature neurons were more sensitive to the damaging effects of Cd²⁺ than immature ones. ZnCl₂ (0.01-0.03 mM) significantly protected neurons from this toxic effect. In contrast to ZnCl₂, CuCl₂ (0.01 mM) increased cadmium neurotoxicity. Using Fluo-4 AM, measurements of intracellular calcium ions demonstrated that 24 h-exposure to Cd²⁺ induced intensive increase in Fluo-4 fluorescence in neurons, which was significantly reduced by zinc ions. CuCl₂ increased the cadmium-induced Fluo-4 and MitoSOX Red fluorescence in neurons. The chelator of intracellular Ca²⁺ BAPTA significantly decreased Cd²⁺-induced intensive increase in Fluo-4 fluorescence in cells.

CONCLUSION

The data obtained by us indicate that Zn²⁺ and Cu²⁺ can affect the neurotoxicity of cadmium in different directions: Zn²⁺ weaken the violation of intracellular calcium homeostasis caused by cadmium, preventing cell death, while Cu²⁺ potentiate the increase in the level of free intracellular calcium induced by cadmium and the development of mitochondrial dysfunction with an increase in the production of free radicals in differentiated cultured neurons of the cerebral cortex, which ultimately stimulates cytotoxicity.

Dendropanoxide, a Triterpenoid from Dendropanax morbifera, Ameliorates Hepatic Fibrosis by Inhibiting Activation of Hepatic Stellate Cells through Autophagy Inhibition

Hepatic fibrosis results from chronic liver damage and is characterized by excessive accumulation of extracellular matrix (ECM). In this study, we showed that dendropanoxide (DPX), isolated from Dendropanax morbifera, had anti-fibrotic effects on hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. DPX suppressed mRNA and protein expression of α-SMA, fibronectin, and collagen in activated HSCs. Moreover, DPX (40 mg/kg) treatment significantly lowered levels of liver injury markers (aspartate aminotransferase and alanine transaminase), expression of fibrotic markers, and deposition of ECM in a carbon tetrachloride-induced mouse model. Anti-fibrotic effects of DPX were comparable to those of silymarin in a hepatic fibrosis mouse model. As a possible mechanism of anti-fibrotic effects, we showed that DPX inhibited autophagosome formation (LC3B-II) and degradation of p62, which have important roles in HSC activation. These findings suggest that DPX inhibits HSC activation by inhibiting autophagy and can be utilized in hepatic fibrosis therapy.

Effects of the aqueous extract of Phyllanthus niruri Linn during pregnancy and lactation on neurobehavioral parameters of rats' offspring

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus niruri L. (Phyllanthaceae) is a plant used in traditional medicine, mainly to treat kidney stones. However, the effects of maternal exposure to P. niruri remain poorly explored.

AIM OF THE STUDY

The objective of this study was to investigate the effects of administration of aqueous extract of P. niruri (AEPN) during pregnancy and lactation, in maternal toxicity, reflex maturation, and offspring memory.

MATERIALS AND METHODS

Pregnant rats were divided into three groups (n = 8/group): Control (vehicle), AEPN 75, and AEPN 150 (each respectively treated with P. niruri at a dose of 75 and 150 mg/kg/day). The animals were treated via intragastric gavage during pregnancy and lactation. Weight gain, feed intake, and reproductive performance were analyzed in the mothers. In the offspring, the following tests were performed: Neonatal Reflex Ontogeny, Open Field Habituation Test and the Object Recognition Test in adulthood.

RESULTS

Maternal exposure to AEPN did not influence weight gain, feed intake, or reproductive parameters. In the offspring, anticipation of reflex ontogenesis (time of completion) was observed (p < 0.05). During adulthood, the AEPN groups presented decreases in exploratory activity upon their second exposure to the Open Field Habituation Test (in a dose-dependent manner) (p < 0.05). In the Object Recognition Test, administration of the extract at 75 and 150 mg/kg induced significant dose-dependent improvements in short and long-term memory (p < 0.05).

CONCLUSION

Administration of the AEPN accelerated the reflex maturation in neonates, and improved offspring memory while inducing no maternal or neonatal toxicity.

Synergistic Protection by Isoquercitrin and Quercetin against Glutamate-Induced Oxidative Cell Death in HT22 Cells via Activating Nrf2 and HO-1 Signaling Pathway: Neuroprotective Principles and Mechanisms of Dendropanax morbifera Leaves

Dendropanax morbifera leaves (DML) have long been used as traditional medicine to treat diverse symptoms in Korea. Ethyl acetate-soluble extracts of DML (DMLE) rescued HT22 mouse hippocampal neuronal cells from glutamate (Glu)-induced oxidative cell death; however, the protective compounds and mechanisms remain unknown. Here, we aimed to identify the neuroprotective ingredients and mechanisms of DMLE in the Glu-HT22 cell model. Five antioxidant compounds were isolated from DMLE and characterized as chlorogenic acid, hyperoside, isoquercitrin, quercetin, and rutin by spectroscopic methods. Isoquercitrin and quercetin significantly inhibited Glu-induced oxidative cell death by restoring intracellular reactive oxygen species (ROS) levels and mitochondrial superoxide generation, Ca²⁺ dysregulation, mitochondrial dysfunction, and nuclear translocation of apoptosis-inducing factor. These two compounds significantly increased the expression levels of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the presence or absence of Glu treatment. Combinatorial treatment of the five compounds based on the equivalent concentrations in DMLE showed that significant protection was found only in the cells cotreated with isoquercitrin and quercetin, both of whom showed prominent synergism, as assessed by drug–drug interaction analysis. These findings suggest that isoquercitrin and quercetin are the active principles representing the protective effects of DMLE, and these effects were mediated by the Nrf2/HO-1 pathway.

Single-cell RNA sequencing of mouse neural stem cell differentiation reveals adverse effects of cadmium on neurogenesis

Cadmium (Cd) is a toxic heavy metal and widely exists in the environment. Extensive studies have revealed that Cd exposure can elicit neurotoxicity and potentially interfere with neurogenesis. However, underlying mechanisms by which Cd exposure affects neurogenesis remain unclear. In this study, we performed single-cell RNA sequencing (scRNA-seq) of the differentiated mixture from neonatal mouse Neural Stem Cells (mNSCs) that were exposed to Cd for 24 h and differentiated for 7 days. Our results showed that Cd exposure led to an increase in the differentiation of NSCs into astrocytes while a decrease into neurons. Besides, Cd induced subtype-specific response and dysregulated cell-to-cell communication. Collectively, our scRNA-seq data suggested that Cd had toxic effects on NSCs differentiation at the single-cell level, which offered insight into the potential molecular mechanism of Cd on neurogenesis. Furthermore, our findings provided a new method for assessing the neurodevelopmental toxicity of environmental pollutants.

Potentiation of the apoptotic signaling pathway in both the striatum and hippocampus and neurobehavioral impairment in rats exposed chronically to a low-dose of cadmium

Cadmium (Cd) is a highly toxic heavy metal. It accumulates in biological tissues, especially in fish which constitutes a first rank food for humans, particularly in the coastal areas. This study investigates the effect of long-term exposure to low Cd concentration (17 μg/kg/day) in rat striatum and hippocampus. In this study, the neurobehavioral ability changes were assessed by applying cognitive standard testing at the end of the rats' exposure period. In addition, the examination of mitochondrial swelling was performed at the same time of evaluation of its redox status in the brain regions studied through stress parameters (GSH, MDA, GST, and CAT). This study examined also whether this long-term exposure can modify the apoptotic signaling pathway via assessment of apoptotic markers (caspase-8 and 9, Bax, Bcl-2, and Cyt-c) in cell lysates. The results of this study showed changes in neurobehavioral abilities of animals and a stronger mitochondrial swelling associated with a significant decrease in antioxidant systems (GSH, GST, and CAT) and conversely an increase in the lipoperoxidation end product (MDA) in both the striatal and hippocampal mitochondria. In addition, the results revealed a significant increase in pro-apoptotic intracellular components such as caspase-9, Cyt-c, and Bax, and showed also an evident decrease in Bcl-2 levels. In conclusion, our results reported that chronic exposure to Cd produces behavioral and cognitive perturbations, enhances oxidative stress associated with mitochondrial edema and Cyt-c leakage, and, ultimately, potentiates apoptosis signaling pathway in both brain regions in rats.

Dendropanax Morbiferus and Other Species from the Genus Dendropanax: Therapeutic Potential of Its Traditional Uses, Phytochemistry, and Pharmacology

The Dendropanax genus is a kind of flowering plant in the family of Araliaceae that encompasses approximately 91 to 95 species. Several Dendropanax species are used as traditional medicinal plants, extensively used Korea and South America and other parts of the world. Almost every part of the plant, including the leaves, bark, roots, and stems, can be used as traditional medicine for the prevention and management of a broad spectrum of health disorders. This paper sought to summarizes the ethnopharmacological benefits, biological activities, and phytochemical investigations of plants from the genus Dendropanax, and perhaps to subsequently elucidate potential new perspectives for future pharmacological research to consider. Modern scientific literature suggests that plants of the Dendropanax genus, together with active compounds isolated from it, possess a wide range of therapeutic and pharmacological applications, including antifungal, anti-complement, antioxidant, antibacterial, insect antifeedant, cytotoxic, anti-inflammatory, neuroprotective, anti-diabetic, anti-cancer, and anti-hypouricemic properties. The botanical descriptions of approximately six to 10 species are provided by different scientific web sources. However, only six species, namely, D. morbiferus, D. gonatopodus, D. dentiger, D. capillaris, D. chevalieri, and D. arboreus, were included in the present investigation to undergo phytochemical evaluation, due to the unavailability of data for the remaining species. Among these plant species, a high concentration of variable bioactive ingredients was identified. In particular, D. morbifera is a traditional medicinal plant used for the multiple treatment purposes and management of several human diseases or health conditions. Previous experimental evidence supports that the D. morbifera species could be used to treat various inflammatory disorders, diarrhea, diabetes, cancer, and some microbial infections. It has recently been reported, by our group and other researchers, that D. morbifera possesses a neuroprotective and memory-enhancing agent. A total of 259 compounds have been identified among six species, with 78 sourced from five of these species reported to be bioactive. However, there is no up-to-date information concerning the D. morbifera, its different biological properties, or its prospective benefits in the enhancement of human health. In the present study, we set out to conduct a comprehensive analysis of the botany, traditional medicinal history, and medicinal resources of species of the Dendropanax genus. In addition, we explore several phytochemical constituents identified in different species of the Dendropanax genus and their biological properties. Finally, we offer comprehensive analysis findings of the phytochemistry, medicinal uses, pharmacological actions, and a toxicity and safety evaluation of the D. morbifera species and its main bioactive ingredients for future consideration.

Neuroprotective effects of Dendropanax morbifera leaves on glutamate-induced oxidative cell death in HT22 mouse hippocampal neuronal cells

ETHNOPHARMACOLOGICAL RELEVANCE

Dendropanax morbifera (DM) has long been used as a traditional herbal medicine for migraines. Glutamate toxicity and oxidative stress have emerged as the possible triggers implicated in migraine pathogenesis.

AIM OF THE STUDY

We aimed to examine the neuroprotective effects of DM leaves (DML) on glutamate-induced oxidative cell death in HT22 mouse hippocampal neuronal cells.

MATERIALS AND METHODS

Molecular authentication of DML was assessed using DNA barcoding analysis. Four different solvent extracts of DML were prepared and subjected to antioxidant activity and phytochemical assays. Neuroprotective effects of DML extracts were evaluated using relevant biochemical and imaging assays that measure cell viability/death, ROS generation, Ca²⁺ levels, mitochondrial dysfunction, and AIF nuclear translocation.

RESULTS

The sequences of matK, rbcL, atpF-H, and psbK-I in DML were identical with those in voucher specimens, confirming that DML was indeed D. morbifera. The ethyl acetate extract of DML (DMLE) showed the highest flavonoid and phenolic content, and prominent DPPH/superoxide radical scavenging and reducing power activities. In the HT22 cell model, glutamate was shown to be the causative agent for apoptotic cell death via elevation of intracellular ROS and Ca²⁺ levels, induction of mitochondrial depolarization and membrane permeabilization, and translocation of AIF to the nucleus. Of note, N-acetyl-L-cysteine and necrostatin-1, but not z-VAD-fmk, completely prevented glutamate-induced cell death, implying that oxidative stress and AIF translocation were pivotal in glutamate cytotoxicity. DMLE significantly recovered glutamate-induced apoptotic cell death in a concentration-dependent manner. It completely inhibited intracellular/mitochondrial ROS generation, the elevation of Ca²⁺ levels, and mitochondrial dysfunction induced by glutamate during early exposure within 8 h. It significantly reversed subsequent AIF nuclear translocation after 12 h of treatment. Antioxidant activities of DMLE may be the protective mechanism that regulates homeostatic balance of ROS and Ca²⁺ as well as maintains mitochondrial function.

CONCLUSIONS

DMLE shows significant neuroprotective effects against glutamate-induced oxidative neuronal cell death. Therefore, DM could be a potential therapeutic candidate for neurological disorders propagated by glutamate toxicity.

Dendropanax morbiferus leaf extract facilitates oligodendrocyte development

Treatment of multiple sclerosis is effective when anti-inflammatory, neuroprotective and regenerative strategies are combined. Dendropanax morbiferus (DM) has anti-inflammatory, anti-oxidative properties, which may be beneficial for multiple sclerosis. However, there have been no reports on the effects of DM on myelination, which is critical for regenerative processes. To know whether DM benefits myelination, we checked differentiation and myelination of oligodendrocytes (OLs) in various primary culture systems treated with DM leaf EtOH extracts or control. DM extracts increased the OL membrane size in the mixed glial and pure OL precursor cell (OPC) cultures and changed OL-lineage gene expression patterns in the OPC cultures. Western blot analysis of DM-treated OPC cultures showed upregulation of MBP and phosphorylation of ERK1/2. In myelinating cocultures, DM extracts enhanced OL differentiation, followed by increased axonal contacts and myelin gene upregulations such as Myrf, CNP and PLP. Phytochemical analysis by LC-MS/MS identified multiple components from DM extracts, containing bioactive molecules such as quercetin, cannabidiol, etc. Our results suggest DM extracts enhance OL differentiation, followed by an increase in membrane size and axonal contacts, thereby indicating enhanced myelination. In addition, we found that DM extracts contain multiple bioactive components, warranting further studies in relation to finding effective components for enhancing myelination.

Prenatal Exposure to Cadmium During Organogenesis Impairs Memory in Young Rats

Pregnant rats were treated with 0.3 and 0.6 mg cadmium (CdCl₂)/kg injected subcutaneously on a daily basis from gestational day 7 to day 15 (organogenesis period). One control group was not injected and other received saline. The 45-day-old offspring were tested in a step-down inhibitory avoidance to evaluate short-term and long-term memory and in a radial maze for the study of spatial memory. These studies showed that gestational exposure to 0.6 mg Cd/kg produced in the male offspring a significant impairment in the retention of long-term memory evaluated 24 hours after training in the step-down inhibitory avoidance. The radial maze also demonstrated that the male offspring prenatally exposed to 0.6 mg Cd presented a significant deficit in the retention of spatial memory evaluated 42 days after training. These results demonstrate that the exposure to Cd during organogenesis may affect the retention of some types of memory.

Leaf extracts from Dendropanax morbifera Léveille mitigate mercury-induced reduction of spatial memory, as well as cell proliferation, and neuroblast differentiation in rat dentate gyrus

Background

The brain is susceptible to methylmercury toxicity, which causes irreversible damage to neurons and glia and the leaf extract Dendropanax morbifera Léveille (DML) has various biological functions in the nervous system. In this study, we examined the effects of DML on mercury-induced proliferating cells and differentiated neuroblasts.

Methods

Dimethylmercury (5 μg/kg) and galantamine (5 mg/kg) was administered intraperitoneally and/or DML (100 mg/kg) was orally to 7-week-old rats every day for 36 days. One hour after the treatment, novel object recognition test was examined. In addition, spatial probe tests were conducted on the 6th day after 5 days of continuous training in the Morris swim maze. Thereafter, the rats were euthanized for immunohistochemical staining analysis with Ki67 and doublecortin and measurement for acetylcholinesterase (AChE) activity.

Results

Dimethylmercury-treated rats showed reduced discrimination index in novel object recognition test and took longer to find the platform than did control group. Compared with dimethylmercury treatment alone, supplementation with DML or galatamine significantly ameliorated the reduction of discrimination index and reduced the time spent to find the platform. In addition, the number of platform crossings was lower in the dimethylmercury-treated group than in controls, while the administration of DML or galantamine significantly increased the number of crossings than did dimethylmercury treatment alone. Proliferating cells and differentiated neuroblasts, assessed by Ki67 and doublecortin immunohistochemical staining was significantly decreased in the dimethylmercury treated group versus controls. Supplementation with DML or galantamine significantly increased the number of proliferating cells and differentiated neuroblasts in the dentate gyrus. In addition, treatment with dimethylmercury significantly increased AChE activity in hippocampal homogenates, while treatment with dimethylmercury+DML or dimethylmercury+galantamine significantly ameliorated this increase.

Conclusions

These results suggest that DML may be a functional food that improves dimethylmercury-induced memory impairment and ameliorates dimethylmercury-induced reduction in proliferating cells and differentiated neuroblasts, and demonstrates corresponding activation of AChE activity in the dentate gyrus.

The Administration of Cadmium for 2, 3 and 4 Months Causes a Loss of Recognition Memory, Promotes Neuronal Hypotrophy and Apoptosis in the Hippocampus of Rats

Cadmium (Cd) is a toxic metal and classified as a carcinogen whose exposure could affect the function of the central nervous system. There are studies that suggest that Cd promotes neurodegeneration in different regions of the brain, particularly in the hippocampus. It is proposed that its mechanism of toxicity maybe by an oxidative stress pathway, which modifies neuronal morphology and causes the death of neurons and consequently affecting cognitive tasks. However, this mechanism is not yet clear. The aim of the present work was to study the effect of Cd administration on recognition memory for 2, 3 and 4 months, neuronal morphology and immunoreactivity for caspase-3 and 9 in rat hippocampi. The results show that the administration of Cd decreased recognition memory. Likewise, it caused the dendritic morphology of the CA1, CA3 and dentate gyrus regions of the hippocampus to decrease with respect to the time of administration of this heavy metal. In addition, we observed a reduction in the density of dendritic spines as well as an increase in the immunoreactivity of caspase-3 and 9 in the same hippocampal regions of the animals treated with Cd. These results suggest that Cd affects the structure and function of the neurons of the hippocampus, which contribute to the deterioration of recognition memory. Our results suggest that the exposure to Cd represents a critical health problem, which if not addressed quickly, could cause much more serious problems in the quality of life of the human population, as well as in the environment in which they develop.

Anti-osteoporotic effects of mixed compositions of extracellular polymers isolated from Aureobasidium pullulans and Textoria morbifera in ovariectomized mice

Background

Extracellular polymeric substances isolated from Aureobasidium pullulans (EAP), containing specifically 13% β-1,3/1,6-glucan, have shown various favorable bone-preserving effects. Textoria morbifera Nakai (TM) tree has been used as an ingredient in traditional medicine and tea for various pharmacological purposes. Thus, the present study was aimed to examine the synergistic anti-osteoporotic potential of mixtures containing different proportions of EAP and TM compared with that of the single formulations of each herbal extract using bilateral ovariectomized (OVX) mice, a renowned rodent model for studying human osteoporosis.

Methods

Thirty five days after bilateral-OVX surgery, 9 combinations of EAP:TM (ratios = 1:1, 1:3, 1:5, 1:7, 1:9, 3:1, 5:1, 7:1, 9:1) and single separate formulations of EAP or TM were supplied orally, once a day for 35 days at a final concentration of 200 mg/kg. Variations in body weight gains during the experimental periods, as well as femur weights, bone mineral density (BMD), bone strength (failure load), and mineral content (calcium [Ca] and inorganic phosphorus [IP]) following sacrifice were measured. Furthermore, histomorphometric and histological profile analyses of serum biochemical parameters (osteocalcin content and bone specific alkaline phosphatase [bALP] activity) were conducted following sacrifice. Femurs histomorphometric analyses were also conducted for bone resorption, structure and mass. The results for the mixed formulations of EAP:TM and separate formulations were compared with those of risedronate sodium (RES).

Results

The EAP:TM (3:1) formulation synergistically enhanced the anti-osteoporotic potential of individual EAP or TM formulations, possibly due to enhanced variety of the active ingredients. Furthermore, the effects of EAP:TM were comparable to those of RES (2.5 mg/kg) treatment.

Conclusion

The results of this study suggest that, the EAP:TM (3:1) combination might act as a new pharmaceutical agent and/or health functional food substance for curing osteoporosis in menopausal women.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2362-y) contains supplementary material, which is available to authorized users.

Medicinal plants with acetylcholinesterase inhibitory activity

Alzheimer's disease, a progressive neurodegenerative disease, is characterised by hypofunction of acetylcholine (ACh) neurotransmitter in the distinct region of brain. Acetylcholinesterase (AChE) is an enzyme that metabolises the ACh at synaptic cleft resulting in Alzheimer's disease. Medicinal plants have been used to treat numerous ailments and improve human health from ancient time. A traditional system of medicine is long recognised for its effective management of neurological disorders. The present review confers the scope of some common medicinal plants with a special focus on AChE-mediated central nervous system complications especially Alzheimer's disease. Literature suggests that medicinal plants reduce neuronal dysfunctions by reducing AChE activity in different brain regions. In some instances, activation of AChE activity by medicinal plants also showed therapeutic potential. In conclusion, medicinal plants have a wide scope and possess therapeutic potential to efficiently manage neurological disorders associated with AChE dysregulation.

Polyacetylene From Dendropanax morbifera Alleviates Diet-Induced Obesity and Hepatic Steatosis by Activating AMPK Signaling Pathway

The extract tea of Dendropanax morbifera is popular beverages in Korea, and their preventive and therapeutic roles in metabolic disorders have been reported. However, the molecular mechanism has not been studied despite the known efficacy of D. morbifera. Eleven fractions (fr.1–fr.11) were divided by MPLC to find the active compound. Among them, Fr.5 was superior to others in that the inhibitory efficacy of de novo triglyceride (TG) biosynthesis. NMR analysis revealed that Fr.5 is composed 98% or more (9Z,16S)-16-hydroxy-9,17-octadecadiene-12,14-diynoic acid (HOD). Treatment of HOD diminished oleic acid (OA)-induced TG accumulation in HepG2 hepatocytes and differentiation of 3T3-L1 preadipocytes by activating LKB1/AMPK. In addition, we determined the effect of the oral administration of the extract of D. morbifera on obesity and hepatic steatosis in high-fat diet (HFD)-induced obese mice. This study proved that D. morbifera containing HOD, the active substance, can show preventive or therapeutic efficacy on obesity and hepatic steatosis through the targeting LKB1/AMPK axis.

Antioxidant activity and contents of leaf extracts obtained from Dendropanax morbifera LEV are dependent on the collecting season and extraction conditions

This study compared the antioxidant activity of extracts from Dendropanax morbifera (D. morbifera) Levillis leaves. The concentrations of flavonoids and polyphenols were measured in extracts of D. morbifera leaves. The antioxidant activities were examined by ABTS and DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP). Total flavonoid and polyphenol contents, and FRAP were highest in the 30% ethanol extract collected in May. The ABTS and DPPH radical scavenging activities were the highest in the 60% ethanol extract harvested in May. For investigating the relationship between antioxidant activity and specific polyphenols, rutin and chlorogenic acid of the polyphenol component were quantified by LC-MS/MS analysis. The concentrations of them were highest in the 60% ethanol extract collected in May, and showed positive correlations with antioxidant activities. The optimal extraction conditions to yield the most effective antioxidant activity were obtained using a 60% ethanol extraction solvent with samples collected in May.

Dendropanax morbifera Léveille extract ameliorates D-galactose-induced memory deficits by decreasing inflammatory responses in the hippocampus

In the present study, we examined the effects of Dendropanax morbifera Léveille leaf extract (DML) on D-galactose-induced morphological changes in microglia and cytokines, including pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) and anti-inflammatory cytokines (IL-4 and IL-10) in the hippocampus. Administration of DML to D-galactose-treated mice significantly improved D-galactose-induced reduction in escape latency, swimming speed, and spatial preference for the target quadrant. In addition, administration of DML to D-galactose-treated mice significantly ameliorated the microglial activation and increases of IL-1β, IL-6, and TNF-α levels in the hippocampus. Administration of D-galactose significantly reduced IL-4 levels in the hippocampus, while administration of DML to D-galactose-treated mice significantly increased IL-4 level. However, we did not observe any significant changes in IL-10 levels in hippocampal homogenates. These results suggest that DML reduces D-galactose-induced mouse senescence by reducing pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α, as well as increasing anti-inflammatory cytokine IL-4.