Anti-amnesic effect of Dendropanax morbifera via JNK signaling pathway on cognitive dysfunction in high-fat diet-induced diabetic mice

3,5-DCQA as a Major Molecule in MeJA-Treated Dendropanax morbifera Adventitious Root to Promote Anti-Lung Cancer and Anti-Inflammatory Activities

(1) Background: Phytochemicals are crucial antioxidants that play a significant role in preventing cancer. (2) Methods: We explored the use of methyl jasmonate (MeJA) in the in vitro cultivation of D. morbifera adventitious roots (DMAR) and evaluated its impact on secondary metabolite production in DMAR, optimizing concentration and exposure time for cost-effectiveness. We also assessed its anti-inflammatory and anti-lung cancer activities and related gene expression levels. (3) Results: MeJA treatment significantly increased the production of the phenolic compound 3,5-Di-caffeoylquinic acid (3,5-DCQA). The maximum 3,5-DCQA production was achieved with a MeJA treatment at 40 µM for 36 h. MeJA-DMARE displayed exceptional anti-inflammatory activity by inhibiting the production of nitric oxide (NO) and reactive oxygen species (ROS) in LPS-induced RAW 264.7 cells. Moreover, it downregulated the mRNA expression of key inflammation-related cytokines. Additionally, MeJA-DMARE exhibited anti-lung cancer activity by promoting ROS production in A549 lung cancer cells and inhibiting its migration. It also modulated apoptosis in lung cancer cells via the Bcl-2 and p38 MAPK pathways. (4) Conclusions: MeJA-treated DMARE with increased 3,5-DCQA production holds significant promise as a sustainable and novel material for pharmaceutical applications thanks to its potent antioxidant, anti-inflammatory, and anti-lung cancer properties.

Platycodin D Ameliorates Cognitive Impairment in Type 2 Diabetes Mellitus Mice via Regulating PI3K/Akt/GSK3β Signaling Pathway

Objectives: The aim of this study was to investigate the ameliorative effect of platycodin D (PD) on cognitive dysfunction in type 2 diabetes mellitus (T2DM) and its potential molecular mechanisms of action in vivo and in vitro. Materials and methods: An animal model of cognitive impairment in T2DM was established using a single intraperitoneal injection of streptozotocin (100 mg/kg) after 8 weeks of feeding a high-fat diet to C57BL/6 mice. In vitro, immunofluorescence staining and Western blot were employed to analyze the effects of PD on glucose-induced neurotoxicity in mouse hippocampal neuronal cells (HT22). Results: PD (2.5 mg/kg) treatment for 4 weeks significantly suppressed the rise in fasting blood glucose in T2DM mice, improved insulin secretion deficiency, and reversed abnormalities in serum triglyceride, cholesterol, low-density lipoprotein, and high-density lipoprotein levels. Meanwhile, PD ameliorated choline dysfunction in T2DM mice and inhibited the production of oxidative stress and apoptosis-related proteins of the caspase family. Notably, PD dose-dependently prevents the loss of mitochondrial membrane potential, promotes phosphorylation of phosphatidylinositol 3 kinase and protein kinase B (Akt) in vitro, activates glycogen synthase kinase 3β (GSK3β) expression at the Ser9 site, and inhibits Tau protein hyperphosphorylation. Conclusions: These findings clearly indicated that PD could alleviate the neurological damage caused by T2DM, and the phosphorylation of Akt at Ser473 may be the key to its effect.

Extracts from Dendropanax morbifera leaves ameliorates cerebral ischemia-induced hippocampal damage by reducing oxidative damage in gerbil

AIM

In this study, we investigated the effects of Dendropanax morbifera extract (DME) on neuroprotection against ischemic damage in gerbils.

METHODS

DME (100 or 300 mg/kg) was orally administered to gerbils for three weeks, and 2 h after the last DME treatment, transient forebrain ischemia in the common carotid arteries was induced for 5 min. The forebrain ischemia-related cognitive impairments were assessed by spontaneous motor activity and passive avoidance test one and four days after ischemia, respectively. In addition, surviving and degenerating neurons were morphologically confirmed by neuronal nuclei immunohistochemical staining and Fluoro-Jade C staining, respectively, four days after ischemia. Changes of glial morphology were visualized by immunohistochemical staining for each marker such as glial fibrillary acidic protein and ionized calcium-binding protein. Oxidative stress was determined by measurements of dihydroethidium, O2· (formation of formazan) and malondialdehyde two days after ischemia. In addition, glutathione redox system such as reduced glutathione, oxidized glutathione levels, glutathione peroxidase, and glutathione reductase activities were measured two days after ischemia.

RESULTS

Spontaneous motor activity monitoring and passive avoidance tests showed that treatment with 300 mg/kg DME, but not 100 mg/kg, significantly alleviated ischemia-induced memory impairments. In addition, approximately 67 % of mature neurons survived and 29.3 % neurons were degenerated in hippocampal CA1 region four days after ischemia, and ischemia-induced morphological changes in astrocytes and microglia were decreased in the CA1 region after 300 mg/kg DME treatment. Furthermore, treatment with 300 mg/kg DME significantly ameliorated ischemia-induced oxidative stress, such as superoxide formation and lipid peroxidation, two days after ischemia. In addition, ischemia-induced reduction of the glutathione redox system in the hippocampus, assessed two days after the ischemia, was ameliorated by treatment with 300 mg/kg DME. These suggest that DME can potentially reduce ischemia-induced neuronal damage through its antioxidant properties.

Protective Effect of Lonicera japonica on PM2.5-Induced Pulmonary Damage in BALB/c Mice via the TGF-β and NF-κB Pathway

This study aimed to assess the protective effect of an extract of Lonicera japonica against particulate-matter (PM)_2.5-induced pulmonary inflammation and fibrosis. The compounds with physiological activity were identified as shanzhiside, secologanoside, loganic acid, chlorogenic acid, secologanic acid, secoxyloganin, quercetin pentoside, and dicaffeoyl quinic acids (DCQA), including 3,4-DCQA, 3,5-DCQA, 4,5-DCQA, and 1,4-DCQA using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS^E). The extract of Lonicera japonica reduced cell death, reactive oxygen species (ROS) production, and inflammation in A549 cells. The extract of Lonicera japonica decreased serum T cells, including CD4⁺ T cells, CD8⁺ T cells, and total T helper 2 (Th2) cells, and immunoglobulins, including immunoglobulin G (IgG) and immunoglobulin E (IgE), in PM_2.5-induced BALB/c mice. The extract of Lonicera japonica protected the pulmonary antioxidant system by regulating superoxide dismutase (SOD) activity, reduced glutathione (GSH) contents, and malondialdehyde (MDA) levels. In addition, it ameliorated mitochondrial function by regulating the production of ROS, mitochondrial membrane potential (MMP), and ATP contents. Moreover, the extract of Lonicera japonica exhibited a protective activity of apoptosis, fibrosis, and matrix metalloproteinases (MMPs) via TGF-β and NF-κB signaling pathways in lung tissues. This study suggests that the extract of Lonicera japonica might be a potential material to improve PM_2.5-induced pulmonary inflammation, apoptosis, and fibrosis.

Anti-Periodontitis Effects of Dendropanax morbiferus H.Lév Leaf Extract on Ligature-Induced Periodontitis in Rats

Periodontitis is caused by pathogens in the oral cavity. It is a chronic infectious disease that causes symptoms including gingival bleeding and tooth loss resulting from the destruction of periodontal tissues coupled with inflammation. Dendropanax morbiferus H.Lév (DM) is a natural product that exhibits various biological activities with few side effects. In this study, the potential of DM leaf hot-water extracts (DMWE) as a treatment for periodontitis was determined and its anti-oxidant and anti-inflammatory effects were evaluated. Compounds in DMWE were identified by high-performance liquid chromatography (HPLC) and nitric oxide (NO) and prostaglandin E₂ (PGE₂) production was measured in RAW 264.7 cells. We measured the gingival index and gingival sulcus depth, and micro-CT was performed in vivo using a ligature-induced periodontitis rat model, which is similar to human periodontitis. The DMWE-treated group exhibited a decrease in cytokine concentration and relieved the gingival index and gingival sulcus depth compared with the periodontitis-induced control group. In addition, micro-CT and histological analysis revealed that DMWE exhibited anti-inflammatory effects and improved alveolar bone loss in periodontitis-induced rats. These findings suggest that DMWE has excellent anti-oxidant and anti-inflammatory effects that protect and prevent periodontal tissue damage and tooth loss caused by the inflammatory response.

Leaves of Cedrela sinensis Attenuate Chronic Unpredictable Mild Stress-Induced Depression-like Behavior via Regulation of Hormonal and Inflammatory Imbalance

This study aimed to evaluate the protective effects of ethyl acetate fraction from Cedrela sinensis (EFCS) against chronic unpredictable mild stress (CUMS)-induced behavioral dysfunction and stress response in C57BL/6 mice. The physiological compounds of EFCS were identified as rutin, isoquercitrin, ethyl gallate, quercitrin, kaempferol-3-O-rhamnoside, and ethyl digallate, using UPLC-Q-TOF/MS^E. To evaluate the neuroprotective effect of EFCS, H₂O₂^- and corticosterone-induced neuronal cell viability was conducted in human neuroblastoma MC-IXC cells. It was found that EFCS alleviated depression-like behavior by conducting the sucrose preference test (SPT), forced swimming test (FST), open field test (OFT), and tail suspension test (TST). EFCS inhibited mitochondrial dysfunction related to neuronal energy metabolism by regulating reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), and ATP contents in brain tissue. In addition, the administration of EFCS regulated the stress hormones in serum. EFCS regulated stress-related indicators such as CRF, ACTH, CYP11B1, and BDNF. Moreover, EFCS downregulated the inflammatory responses and apoptosis proteins such as caspase-1, TNF-α, IL-1β, p-JNK, BAX, and p-tau in brain tissues. These results suggest that EFCS might be a potential natural plant material that alleviates CUMS-induced behavior disorder by regulating inflammation in brain tissue against CUMS-induced depression.

Microwave-Assisted Dendropanax morbifera Extract for Cosmetic Applications

Recently, utilizing natural bioactive compounds for active ingredients in cosmetics has become a growing worldwide trend. More and more studies aim to identify the sources of herbal ingredients for applications in the pharmaceutical and cosmetic fields. Additionally, in order to optimize the safety of natural ingredients, choosing an environmentally friendly extraction method also plays an important role. In this work, an eco-friendly extraction technique for Dendropanax morbifera using microwave treatment and microwave-assisted Dendropanax morbifera extract (MA-DME) was investigated. The results indicate that higher yields of MA-DME were obtained than with conventional methods and that D. morbifera’s antioxidant properties were enhanced. Moreover, we found that MA-DME exhibited extraordinary antioxidant, anti-aging, and skin-whitening activities. We suggest MA-DME as a potential cosmeceutical ingredient than could be utilized for comprehensive protection of human skin.

Knockdown of NRSF Alleviates Ischemic Brain Injury and Microvasculature Defects in Diabetic MCAO Mice

Diabetes is one of the well-established risk factors of stroke and is associated with a poor outcome in patients with stroke. Previous studies have shown that the expression of neuron restrictive silencer factor (NRSF) is elevated in diabetes as well as ischemic stroke. However, the role of NRSF in regulating an outcome of diabetic ischemic stroke has not been completely understood. Here, we hypothesized that diabetes-induced NRSF elevation can aggravate brain injury and cognition impairment in ischemic stroke. The diabetic ischemic stroke mice model was established by 8 weeks of high-fat-diet feeding and 5 days of streptozotocin injection followed by 30 min of middle cerebral artery occlusion (MCAO). We found that diabetes enhanced the MCAO-induced elevation of NRSF in the hippocampus in accompany with an elevation of its corepressors, HDAC1, and mSin3A, and decrease of β-TrCP. By using histological/immunofluorescence staining and neurobehavioral testing, our results showed that the brain damage and learning/memory impairment were aggravated in diabetic ischemic mice but significantly attenuated after stereotaxic injection of NRSF-shRNA. Meanwhile, by performing whole-brain clearing with PEGASOS, microvascular reconstruction, western blotting, and ELISA, we found that NRSF-shRNA markedly alleviated the vasculature disorders and rescued the suppression of NRP-1, VEGF, and VEGFR2 in the hippocampus of diabetic ischemic mice. Therefore, our results demonstrated for the first time that the elevation of hippocampal NRSF plays an important role in alleviating brain injury and cognitive disabilities in diabetic ischemic mice, potentially via the reduction of NRP-1/VEGF signaling.

Anti-Amnesic Effects of Epigallocatechin Gallate on Scopolamine-Induced Learning and Memory Dysfunction in Sprague-Dawley Rats

Epigallocatechin gallate (EGCG) is a major flavan-3-ol of green tea polyphenols that exhibits various beneficial health effects, including antioxidant, anti-bacterial, and anti-inflammatory properties. This study aimed to evaluate whether EGCG prevents scopolamine-induced learning and memory impairment in in vivo and ex vivo models. Male Sprague-Dawley (SD) rats were pre-treated with EGCG (5 mg/kg/day; intraperitoneal injection (i.p.)) for 10 days. Then, EGCG and scopolamine (1 mg/kg/day; i.p.) were applied 60 and 30 min before the behavioral tests, respectively, for another 9 days. EGCG alleviated the cognitive deficits in the Y-maze, passive avoidance, and Morris water maze tests. EGCG showed improved cholinergic functions by decreasing acetylcholinesterase activity in hippocampi dissected from the brain of the rats after the behavioral tests. EGCG also reduced oxidative stress, partly due to increased superoxide dismutase activity and decreased malondialdehyde level in the hippocampi of the rat brains after the behavioral tests. Furthermore, EGCG attenuated the scopolamine-induced blockade of long-term potentiation in organotypic hippocampal tissue of seven-day-old SD rats. Taken together, these results suggested that EGCG is a potential therapeutic agent for alleviating cognitive dysfunction.

The role of traditional Chinese medicine in the treatment of cognitive dysfunction in type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic cognitive dysfunction (DCD) is mainly one of the complications of type 2 diabetes mellitus (T2DM) with complex and obscure pathogenesis. Extensive evidence has demonstrated the effectiveness and safety of traditional Chinese medicine (TCM) for DCD management.

AIM OF THE STUDY

This review attempted to systematically summarize the possible pathogenesis of DCD and the current Chinese medicine on the treatment of DCD.

MATERIALS AND METHODS

We acquired information of TCM on DCD treatment from PubMed, Web of Science, Science Direct and CNKI databases. We then dissected the potential mechanisms of currently reported TCMs and their active ingredients for the treatment of DCD by discussing the deficiencies and giving further recommendations.

RESULTS

Most TCMs and their active ingredients could improve DCD through alleviating insulin resistance, microvascular dysfunction, abnormal gut microbiota composition, inflammation, and the damages of the blood-brain barrier, cerebrovascular and neurons under hyperglycemia conditions.

CONCLUSIONS

TCM is effective in the treatment of DCD with few adverse reactions. A large number of in vivo and in vitro, and clinical trials are still needed to further reveal the potential quality markers of TCM on DCD treatment.

The role of microRNAs in diseases and related signaling pathways

MicroRNAs (miRNAs) are epigenetic regulators of the gene expression and act through posttranslational modification. They bind to 3'-UTR of target mRNAs to inhibit translation or increase the degradation mRNA in many tissues. Any alteration in the level of miRNA expression in many human diseases indicates their involvement in the pathogenesis of many diseases. On the other hand, the regulation of the signaling pathways is necessary for the maintenance of natural and physiological characteristics of any cell. It is worth mentioning that dysfunction of the signaling pathways manifests itself as a disorder or disease. The significant evidence report that miRNAs regulate the several signaling pathways in many diseases. Base on previous studies, miRNAs can be used for therapeutic or diagnostic purposes. According to the important role of miRNAs on the cell signaling pathways, this article reviews miRNAs involvement in incidence of diseases by changing signaling pathways.

Securidaca inappendiculata Polyphenol Rich Extract Counteracts Cognitive Deficits, Neuropathy, Neuroinflammation and Oxidative Stress in Diabetic Encephalopathic Rats via p38 MAPK/Nrf2/HO-1 Pathways

Diabetic encephalopathy is one of the serious emerging complication of diabetes. Securidaca inappendiculata is an important medicinal plant with excellent antioxidant and anti-inflammatory properties. This study investigated the neuroprotective effects of S. inappendiculata polyphenol rich extract (SiPE) against diabetic encephalopathy in rats and elucidated the potential mechanisms of action. Type 2 diabetes mellitus (T2DM) was induced using high fructose solution/intraperitoneal injection of streptozotocin and the diabetic rats were treated with SiPE (50, 100 and 200 mg/kg) for 8 weeks. Learning and memory functions were assessed using the Morris water and Y maze tests, depressive behaviour was evaluated using forced swimming and open field tests, while neuropathic pain assessment was assessed using hot plate, tail immersion and formalin tests. After the experiments, acetylcholinesterase (AChE), oxidative stress biomarkers and proinflammatory cytokines, caspase-3 and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) were determined by ELISA kits. In addition, the expression levels of p38, phospho-p38 (p-p38), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by western blot analyses. The results indicated that SiPE administration significantly lowered blood glucose level, attenuated body weight loss, thermal/chemical hyperalgesia, improved behavioural deficit in the Morris water maze, Y maze test and reduced depressive-like behaviours. Furthermore, SiPE reduced AChE, caspase-3, NF-κB, malonaldehyde malondialdehyde levels and simultaneously increased antioxidant enzymes activity in the brain tissues of diabetic rats. SiPE administration also significantly suppressed p38 MAPK pathway and upregulated the Nrf2 pathway. The findings suggested that SiPE exerted antidiabetic encephalopathy effects via modulation of oxidative stress and inflammation.

Green tea protects against hippocampal neuronal apoptosis in diabetic encephalopathy by inhibiting JNK/MLCK signaling

Although diabetic encephalopathy (DE) is a major late complication of diabetes, the pathophysiology of postural instability in DE remains poorly understood. Prior studies have suggested that neuronal apoptosis is closely associated with cognitive function, but the mechanism remains to be elucidated. Green tea, which is a non-fermented tea, contains a number of tea polyphenols, alkaloids, amino acids, polysaccharides and other components. Some studies have found that drinking green tea can reduce the incidence of neurodegenerative diseases and improve cognitive dysfunction. We previously found that myosin light chain kinase (MLCK) regulates apoptosis in high glucose-induced hippocampal neurons. In neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, activation of the JNK signaling pathway promotes neuronal apoptosis. However, the relationship between JNK and MLCK remains to be elucidated. Green tea serum was obtained using seropharmacological methods and applied to hippocampal neurons. In addition, a type 1 diabetes rat model was established and green tea extract was administered, and the Morris water maze test, Cell Counting Kit-8 assays, flow cytometry, western blotting and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling assays were used to examine the effects of green tea on hippocampal neuronal apoptosis in diabetic rats. The results demonstrated that green tea can protect against hippocampal neuronal apoptosis by inhibiting the JNK/MLCK pathway and ultimately improves cognitive function in diabetic rats. The present study provided novel insights into the neuroprotective effects of green tea.

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.

Biological and Pharmacological Characterization of Ascorbic Acid and Nicotinamide Chitosan Nanoparticles against Insulin-Resistance-Induced Cognitive Defects: A Comparative Study

High consumption of industrialized food with high fat content is generally associated with insulin resistance, which in turn causes memory impairment and cognitive decline. Nicotinamide and ascorbic acid are among the promising neuroprotective molecules; however, an appreciable therapeutic activity necessitates the administration of a large dose of either. Therefore, the study aimed to assess if loading them in chitosan nanoparticles in doses 5-10 times lower than the unencapsulated forms would achieve comparable therapeutic results. Animals were fed a high-fat-high-fructose (HFHF) diet for 75 days. The vitamins in their conventional form (100 mg/kg) and the nanoparticles under investigation (10 and 20 mg/kg) were given orally concomitantly with the diet in the last 15 days. The intake of HFHF diet for 75 days led to an insulin-resistant state, with memory impairment, which was verified behaviorally through the object recognition test. This was accompanied by significant reduction in brain insulin-like growth factor 1 (IGF-1), increased acetylcholine esterase activity, increase in the serotonin and dopamine turnover ratio, and increase in oxidative stress and 8-OHdG, indicating cellular DNA fragmentation. Cellular energy was also decreased, and immunohistochemical examination verified the high immunoreactivity in both the cortex and hippocampus of the brain. The administration of nanoparticulated nicotinamide or ascorbic acid with a 10 times lesser dose than the unencapsulated forms managed to reverse all aforementioned harmful effects, with an even lesser immunoreactivity score than the unencapsulated form. Therefore, it can be concluded that nicotinamide or ascorbic acid chitosan nanoparticles can be recommended as daily supplements for neuroprotection in patients suffering from insulin resistance after conduction of clinical investigations.

Matcha Improves Metabolic Imbalance-Induced Cognitive Dysfunction

This study was conducted to assess the protective effect of extract of match (EM) on high-fat diet- (HFD-) induced cognitive deficits in male C57BL/6 mice. It was found that EM improved glucose tolerance status by measuring OGTT and IPGTT with HFD-induced mice. EM protected behavioral and memory dysfunction in Y-maze, passive avoidance, and Morris water maze tests. Consumption of EM reduced fat mass, dyslipidemia, and inflammation in adipose tissue. Also, EM ameliorated hepatic and cerebral antioxidant systems. EM improved the cerebral cholinergic system by regulating ACh contents and expression of AChE and ChAT. Also, EM restored mitochondrial function in liver and brain tissue. EM attenuated hepatic inflammatory effect, lipid synthesis, and cholesterol metabolism by regulating the protein expression of TNF-α, TNFR1, p-IRS-1, p-JNK, IL-1β, iNOS, COX-2, HMGCR, PPARγ, and FAS. Finally, EM regulated cognitive function and neuroinflammation in the whole brain, hippocampus, and cerebral cortex by regulating the protein expression of p-JNK, p-Akt, p-tau, Aβ, BDNF, IDE, COX-2, and IL-1β. These findings suggest that EM might be a potential source of functional food to improve metabolic disorder-associated cognitive dysfunction.

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.

Mori Cortex Radicis Attenuates High Fat Diet-Induced Cognitive Impairment via an IRS/Akt Signaling Pathway

Present study was conducted to investigate ameliorating effects of Mori Cortex radicis on cognitive impair and neuronal defects in HFD-induced (High Fat Diet-Induced) obese mice. To induce obesity, C57BL/6 mice were fed an HFD for 8 weeks, and then mice were fed the HFD plus Mori Cortex radicis extract (MCR) (100 or 200 mg/kg/day) for 6 weeks. Prior to sacrifice, body weights were measured, and Y-maze test and oral glucose tolerance test were performed. Serum lipid metabolic biomarkers (TG, LDL, and HDL/total cholesterol ratio) and antioxidant enzymes (glutathione, superoxide dismutase, and catalase), malondialdehyde (MDA), and acetylcholinesterase (AChE) levels were measured in brain tissues. The expressions of proteins related to insulin signaling (p-IRS, PI3K, p-Akt, and GLUT4) and neuronal protection (p-Tau, Bcl-2, and Bax) were examined. MCR suppressed weight gain, improved serum lipid metabolic biomarker and glucose tolerance, inhibited AChE levels and MDA production, and restored antioxidant enzyme levels in brain tissue. In addition, MCR induced neuronal protective effects by inhibiting p-Tau expression and increasing Bcl-2/Bax ratio, which was attributed to insulin-induced increases in the expressions p-IRS, PI3K, p-Akt, and GLUT4. These indicate MCR may reduce HFD-induced insulin dysfunction and neuronal damage and suggest MCR be considered a functional material for the prevention of T2DM-associated neuronal disease.

Effect of Aruncus dioicus var. kamtschaticus Extract on Neurodegeneration Improvement: Ameliorating Role in Cognitive Disorder Caused by High-Fat Diet Induced Obesity

This study was performed to estimate the possibility of using an ethyl acetate fraction from Aruncus dioicus var. kamtschaticus (EFAD) on metabolic syndrome that is induced by a high-fat diet (HFD). It was demonstrated that EFAD suppresses lipid accumulation and improves insulin resistance (IR) caused by Tumor necrosis factor alpha (TNF-α) in in-vitro experiments using the 3T3-L1 cell. In in-vivo tests, C57BL/6 mice were fed EFAD at 20 and 40 mg/kg body weight (BW) for four weeks after the mice were fed HFD for 15 weeks to induce obesity. EFAD significantly suppressed the elevation of BW and improved impaired glucose tolerance in obese mice. Additionally, this study showed that EFAD has an ameliorating effect on obesity-induced cognitive disorder with behavioral tests. The effect of EFAD on peripheral-IR improvement was confirmed by serum analysis and western blotting in peripheral tissues. Additionally, EFAD showed an ameliorating effect on HFD-induced oxidative stress, impaired cholinergic system and mitochondrial dysfunction, which are interrelated symptoms of neurodegeneration, such as Alzheimer’s disease and central nervous system (CNS)-IR in brain tissue. Furthermore, we confirmed that EFAD improves CNS-IR by confirming the IR-related factors in brain tissue. Consequently, this study suggests the possibility of using EFAD for the prevention of neurodegeneration by improving metabolic syndrome that is caused by HFD.

Chronic Alcohol Exposure Induced Neuroapoptosis: Diminishing Effect of Ethyl Acetate Fraction from Aralia elata

An ethyl acetate fraction from Aralia elata (AEEF) was investigated to confirm its neuronal cell protective effect on ethanol-induced cytotoxicity in MC-IXC cells and its ameliorating effect on neurodegeneration in chronic alcohol-induced mice. The neuroprotective effect was examined by methylthiazolyldiphenyl-tetrazolium bromide (MTT) and 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) assays. As a result, AEEF reduced alcohol-induced cytotoxicity and oxidative stress. To evaluate the improvement of learning, memory ability, and spatial cognition, Y-maze, passive avoidance, and Morris water maze tests were conducted. The AEEF groups showed an alleviation of the decrease in cognitive function in alcohol-treated mice. Then, malondialdehyde (MDA) levels and the superoxide dismutase (SOD) content were measured to evaluate the antioxidant effect of AEEF in the brain tissue. Treatment with AEEF showed a considerable ameliorating effect on biomarkers such as SOD and MDA content in alcohol-induced mice. To assess the cerebral cholinergic system involved in neuronal signaling, acetylcholinesterase (AChE) activity and acetylcholine (ACh) content were measured. The AEEF groups showed increased ACh levels and decreased AChE activities. In addition, AEEF prevented alcohol-induced neuronal apoptosis via improvement of mitochondrial activity, including reactive oxygen species levels, mitochondrial membrane potential, and adenosine triphosphate content. AEEF inhibited apoptotic signals by regulating phosphorylated c-Jun N-terminal kinases (p-JNK), phosphorylated protein kinase B (p-Akt), Bcl-2-associated X protein (BAX), and phosphorylated Tau (p-Tau). Finally, the bioactive compounds of AEEF were identified as caffeoylquinic acid (CQA), 3,5-dicaffeoylquinic acid (3,5-diCQA), and chikusetsusaponin IVa using the UPLC-Q-TOF-MS system.

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.

MicroRNA-125b-5p improves pancreatic β-cell function through inhibiting JNK signaling pathway by targeting DACT1 in mice with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive disease, accompanied by increased insulin resistance and deteriorating β-cell function. Previous studies have revealed that microRNA (miRNA) plays a crucial role in the treatment of T2DM. Hence, we aim to investigate the role of microRNA-125b-5p (miR-125b-5p) in pancreatic β-cell function and insulin sensitivity of mice with T2DM with the involvement of Dishevelled antagonist Dapper1 (DACT1) and the c-Jun NH2-terminal kinases (JNK) signaling pathway. Firstly, a mouse model of T2DM was established by administering a high-fat diet plus low dosage of streptozotocin, and function of pancreatic β-cell and insulin sensitivity in the normal and T2DM mice were detected. Then, the pancreatic β-cells were collected from pancreatic islet tissues and treated with different mimics, inhibitors and siRNAs. After that, the relationship among miR-125b-5p, DACT1, and the JNK signaling-related factors in T2DM mice was determined. Finally, cell proliferation and apoptosis were determined. Mice with T2DM had lower pancreatic β-cell function and insulin sensitivity, as well as diminished expression of miR-125b-5p but enhanced expressions of DACT1, JNK and c-Jun. miR-125b-5p inhibited DACT1 expression and the activation of the JNK signaling pathway, as well as restrained cell proliferation and promoted cell apoptosis. The current results suggest that up-regulated miR-125b-5p promotes insulin sensitivity and enhances pancreatic β-cell function through inhibiting the JNK signaling pathway by negatively mediating DACT1.

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.

Dendropanax morbifera Prevents Cardiomyocyte Hypertrophy by Inhibiting the Sp1/GATA4 Pathway

An extract of Dendropanax morbifera branch exerts antioxidant, anti-inflammatory, antithrombotic, and anticancer activities. The purpose of this study was to investigate the effect of the extract in isoproterenol-induced cardiac hypertrophy. Phalloidin staining showed that treatment with the extract dramatically prevents isoproterenol-induced H9c2 cell enlargement and the expression of cardiac hypertrophic marker genes, including atrial natriuretic peptide (ANP) and B-type brain natriuretic peptide (BNP). Further, pretreatment with the extract decreased isoproterenol-induced GATA4 and Sp1 expression in H9c2 cells. Overexpression of Sp1 induced the expression of GATA4. The forced expression of Sp1 or its downstream target GATA4, as well as the co-transfection of Sp1 and GATA4 increased the expression of ANP, which was decreased by treatment with the extract. To further elucidate the regulation of the Sp1/GATA4-mediated expression of ANP, knockdown experiments were performed. Transfection with small interfering RNAs (siRNAs) for Sp1 or GATA4 decreased ANP expression. The extract did not further inhibit the expression of ANP reduced by the transfection of GATA4 siRNA. Sp1 knockdown did not affect the expression of ANP that was induced by the overexpression of GATA4; however, GATA4 knockdown abolished the expression of ANP that had been induced by Sp1 overexpression. The extract treatment also attenuated the isoproterenol-induced activation of p38 MAPK, ERK1/2, and JNK1. Hesperidin, catechin, 2,5-dihydroxybenzoic acid, and salicylic acid are the main phenolic compounds present in the extract as observed by high performance liquid chromatography. Hesperidin and 2,5-dihydroxybenzoic acid attenuated isoproterenol-induced cardiac hypertrophy. These findings suggest that the D. morbifera branch extract prevents cardiac hypertrophy by downregulating the activation of Sp1/GATA4 and MAPK signaling pathways.

Development and Validation of a HPLC-UV Method for Extraction Optimization and Biological Evaluation of Hot-Water and Ethanolic Extracts of Dendropanax morbifera Leaves

Dendropanax morbifera Leveille (Araliaceae) has been used in traditional oriental remedies for cancer, inflammation, diabetes, and thrombosis. However, a validated analytical method, standardization, and optimization of extraction conditions with respect to biological activity have not been reported. In this study, a simple and validated HPLC method for identifying and quantifying active substances in D. morbifera was developed. Hot water and ethanolic D. morbifera leaf extracts from different production regions were prepared and evaluated with regard to their chemical compositions and biological activities. The contents of active compounds such as rutin and chlorogenic acid were determined in four samples collected from different regions. The 80% ethanolic extract showed the best antioxidant activity, phenolic content, reducing power, and xanthine oxidase (XO) inhibitory activity. The validated HPLC method confirmed the presence of chlorogenic acid and rutin in D. morbifera leaf extracts. The antioxidant and XO inhibitory activity of D. morbifera extract could be attributed to the marker compounds. Collectively, these results suggest that D. morbifera leaves could be beneficial for the treatment or prevention of hyperuricemia-related disease, and the validated HPLC method could be a useful tool for the quality control of food or drug formulations containing D. morbifera.

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.

Neuroprotective effects of orientin on oxygen-glucose deprivation/reperfusion-induced cell injury in primary culture of rat cortical neurons

Orientin (luteolin-8-C-glucoside) is a phenolic compound found abundantly in millet, juice, and peel of passion fruit and has been shown to have antioxidant properties. In the present study, we explored the effects of orientin on oxygen-glucose deprivation/reperfusion (OGD/RP)-induced cell injury in primary culture of rat cortical neurons using an in vitro model of neonatal ischemic brain injury. The reduced cell viability and elevated lactate dehydrogenase leakage were observed after OGD/RP exposure, which were then reversed by orientin (10, 20, and 30 µM) pretreatment in a dose-dependent manner. Additionally, OGD/RP treatment resulted in significant oxidative stress, accompanied by enhanced intracellular reactive oxygen species (ROS) generation, and obvious depletion in the activities of intracellular Mn-superoxide dismutase, catalase, and glutathione peroxidase antioxidases. However, these effects were dose dependently restored by orientin pretreatment. We also found that orientin pretreatment dose dependently suppressed [Ca²⁺]_i increase and mitochondrial membrane potential dissipation caused by OGD/RP in primary culture of rat cortical neurons. Western blot analysis showed that OGD/RP exposure induced a distinct decrease of Bcl-2 protein and a marked elevation of Bax, caspase-3, and cleaved caspase-3 proteins; whereas these effects were dose dependently reversed by orientin incubation. Both the caspase-3 activity and the apoptosis rate were increased under OGD/RP treatment, but was then dose dependently down-regulated by orientin (10, 20, and 30 µM) incubation. Moreover, orientin pretreatment dose dependently inhibited OGD/RP-induced phosphorylation of JNK and ERK1/2. Notably, JNK inhibitor SP600125 and ERK1/2 inhibitor PD98059 also dramatically attenuated OGD/RP-induced cell viability loss and ROS generation, and further, orientin failed to protect cortical neurons with the interference of JNK activator anisomycin or ERK1/2 activator FGF-2. Taken together, these results demonstrated that orientin has significant neuroprotective effects against OGD/RP-induced cell injury via JNK and ERK1/2 signaling pathways in primary culture of rat cortical neurons. Impact statement Orientin has been used in traditional eastern medicine and reported to possess antioxidant properties. However, the effects of orientin on neonatal ischemic brain injury and the underlying mechanisms involved have not been studied. Our results showed that orientin exerts significant neuroprotective effects on cell injury caused by oxygen-glucose deprivation/reperfusion via the JNK and ERK1/2 signaling pathways in primary culture of rat cortical neurons, implying the potential therapeutic application of orientin via the suppression of oxidative stress and cell apoptosis. This research suggested that orientin may be used as a therapeutic and preventive option for newborn cerebral ischemia/reperfusion injury.

Ginsenoside Re Ameliorates Brain Insulin Resistance and Cognitive Dysfunction in High Fat Diet-Induced C57BL/6 Mice

The ameliorating effects of ginsenoside Re (G Re) on high fat diet (HFD)-induced insulin resistance in C57BL/6 mice were investigated to assess its physiological function. In the results of behavioral tests, G Re improved cognitive dysfunction in diabetic mice using Y-maze, passive avoidance, and Morris water maze tests. G Re also significantly recovered hyperglycemia and fasting blood glucose level. In the results of serum analysis, G Re decreased triglyceride (TG), total cholesterol (TCHO), low-density lipoprotein cholesterol (LDLC), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) and increased the ratio of high-density lipoprotein cholesterol (HDLC). G Re regulated acetylcholine (ACh), acetylcholinesterase (AChE), malondialdehyde (MDA), superoxide dismutase (SOD), and oxidized glutathione (GSH)/total GSH by regulating the c-Jun N-terminal protein kinase (JNK) pathway. These findings suggest that G Re could be used to improve HFD-induced insulin resistance condition by ameliorating hyperglycemia via protecting the cholinergic and antioxidant systems in the mouse brains.

Effects of Dendropanax morbifera Léveille extract on hypothyroidism-induced oxidative stress in the rat hippocampus

In this experiment, we verified the effects of Dendropanax morbifera Léveille stem extract (DMS) on hypothyroidism-induced oxidative stress in the hippocampus of rats. Hypothyroidism was induced in rats by treating them with 0.03% 2-mercapto-1-methyl-imidazole dissolved in drinking water for 5 weeks. DMS (100 mg/kg) was also orally administered to the rats during the same period and the animals were sacrificed at 12 weeks of age. DMS administration tended to ameliorate these hypothyroidism-induced changes in serum triiodothyronine (T₃), thyroxine (T₄), and thyroid-stimulating hormone levels. DMS administration significantly reduced the hypothyroidism-induced increases in reactive oxygen species production as well as in lipid peroxidation in the hippocampus. In addition, DMS administration increased hippocampal Cu, Zn-superoxide dismutase (SOD1), catalase (CAT), and glutathione peroxidase (GPx) levels. These results suggest that DMS potentially ameliorates hypothyroidism-induced neuroendocrine phenotypes and oxidative stress in the hippocampus via the induction of antioxidant enzymes.