Inhibition of microfold cells ameliorates early pathological phenotypes by modulating microglial functions in Alzheimer's disease mouse model.

BACKGROUND: The gut microbiota has recently attracted attention as a pathogenic factor in Alzheimer's disease (AD). Microfold (M) cells, which play a crucial role in the gut immune response against external antigens, are also exploited for the entry of pathogenic bacteria and proteins into the body. However, whether changes in M cells can affect the gut environments and consequently change brain pathologies in AD remains unknown. METHODS: Five familial AD (5xFAD) and 5xFAD-derived fecal microbiota transplanted (5xFAD-FMT) naïve mice were used to investigate the changes of M cells in the AD environment. Next, to establish the effect of M cell depletion on AD environments, 5xFAD mice and Spib knockout mice were bred, and behavioral and histological analyses were performed when M cell-depleted 5xFAD mice were six or nine months of age. RESULTS: In this study, we found that M cell numbers were increased in the colons of 5xFAD and 5xFAD-FMT mice compared to those of wild-type (WT) and WT-FMT mice. Moreover, the level of total bacteria infiltrating the colons increased in the AD-mimicked mice. The levels of M cell-related genes and that of infiltrating bacteria showed a significant correlation. The genetic inhibition of M cells (Spib knockout) in 5xFAD mice changed the composition of the gut microbiota, along with decreasing proinflammatory cytokine levels in the colons. M cell depletion ameliorated AD symptoms including amyloid-ß accumulation, microglial dysfunction, neuroinflammation, and memory impairment. Similarly, 5xFAD-FMT did not induce AD-like pathologies, such as memory impairment and excessive neuroinflammation in Spib-/- mice. CONCLUSION: Therefore, our findings provide evidence that the inhibiting M cells can prevent AD progression, with therapeutic implications.

Aerial part of Houttuynia cordata reverses memory impairment by regulating amyloid beta accumulation and neuroinflammation in Alzheimer's disease model.

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by amyloid-ß (Aß) deposition, accompanied by neuroinflammation and memory dysfunction. Houttuyniae Herba (aerial parts of Houttuynia cordata, also known as fish mint; HH), an herbal medicine traditionally used to treat fever, urinary disorders, and pus, is revealed to protect neurons from Aß toxicity and regulate cholinergic dysfunction in AD models. In this study, we aimed to investigate the effects of HH on excessive accumulation of Aß followed by neuroinflammation, synaptic degeneration, and memory impairment. Two-month-old 5xFAD transgenic mice were administered HH at 100 mg/kg for 4 months. We observed that HH treatment ameliorated memory impairment and reduced Aß deposits in the brains of the mice. HH directly inhibited Aß aggregation in vitro using the Thioflavin T assay and indirectly suppressed the amyloidogenic pathway by increasing alpha-secretase expression in the mice brain. In addition, HH exerted antineuroinflammatory effects by reducing of glial activation and p38 phosphorylation. Moreover, HH treatment increased the expression of synaptophysin, a presynaptic marker protein. Overall, HH alleviates memory impairment in AD by facilitating nonamyloidogenic pathway and inhibiting neuroinflammation. Therefore, we suggest that HH can be a promising herbal drug for patients with AD requiring multifaceted improvement.

In vitro and in vivo neuroprotective effect of novel mPGES-1 inhibitor in animal model of Parkinson's disease.

mPGES-1 is found to be up-regulated in the dopaminergic neurons of the substantia nigra pars compacta (SNpc) of postmortem brain tissue from Parkinson's disease (PD) patients and neurotoxin 6-hydroxydopamine (6-OHDA)-induced PD mice. Since the genetic deletion of mPGES-1 abolished 6-OHDA-induced PGE2 production and 6-OHDA-induced dopaminergic neurodegeneration in vitro and in vivo models, mPGES-1 enzyme has the potential to be an important target for PD therapy. In the present work, we investigated whether a small organic molecule as mPGES-1 inhibitor could exhibit the neuroprotective effects against 6-OHDA-induced neurotoxicity in in vitro and in vivo models. For this research goal, a new series of arylsulfonyl hydrazide derivatives was prepared and investigated whether these compounds may protect neurons against 6-OHDA-induced neurotoxicity in both in vitro and in vivo studies. Among them, compound 7s (MPO-0144) as a mPGES-1 inhibitor (PGE2 IC50 = 41.77 nM; mPGES-1 IC50 = 1.16 nM) exhibited a potent neuroprotection (ED50 = 3.0 nM) against 6-OHDA-induced in PC12 cells without its own neurotoxicity (IC50 = >10 µM). In a 6-OHDA-induced mouse model of PD, administration of compound 7s (1 mg/kg/day, for 7 days, i.p.) ameliorated motor impairments and dopaminergic neuronal damage. These significant biological effects of compound 7s provided the first pharmacological evidence that mPGES-1 inhibitor could be a promising therapeutic agent for PD patients.

DA-9801, a standardized Dioscorea extract, improves memory function via the activation of nerve growth factor-mediated signaling.

OBJECTIVES: Nerve growth factor (NGF) is a neurotrophin that plays a critical role in mammalian learning and memory functions. NGF also regulates neuronal cell differentiation and neurite outgrowth by activating ERK/CREB signaling. This present study examined the effects of a standardized Dioscorea extract (DA-9801), which is composed of Dioscorea japonica Thunb and Dioscorea nipponica Makino on memory function via its NGF-potentiating activities using an in vitro and in vivo paradigm. METHODS: Cells were incubated with or without different concentrations of DA-9801 (10, 25, and 50 µg/ml) extract for 24 h. The cultured conditioned medium from C6 glioma cells was used for NGF production assay, and neurite length in N2a cells was measured after every 2 h. Mice were orally treated with DA-9801 (10 and 100 mg/kg/day) once daily for 7 days. They were subjected to passive avoidance test to evaluate memory functions. The question of whether DA-9801 induced NGF synthesis was assessed by measuring the levels of NGF in the mouse cortical and hippocampal tissues. Hippocampal cell differentiation and NGF-mediated ERK/CREB signaling were evaluated by performing immunohistochemical analysis using BrdU, ki67, DCX, phosphorylated ERK and CREB in the mouse hippocampus. RESULTS: DA-9801 treatment increased the NGF contents and neurite length, respectively. Mice with DA-9801 administration showed memory enhancement in the passive avoidance test. DA-9801 also increased newborn cell differentiation, neurite length, NGF secretion, and ERK/CREB phosphorylation in the mouse hippocampus. DISCUSSION: These results suggest that DA-9801 treatment could improve memory function by inducing hippocampal NGF synthesis and ERK/CREB signaling.

A novel nutritional mixture, MBN, prevents memory impairment via inhibiting NLRP3 inflammasome formation in 5xFAD transgenic mice.

OBJECTIVES: Amyloid beta (Aß)-induced abnormal neuroinflammation is recognized as a major pathological factor of Alzheimer's disease (AD), which results in memory impairment. Inhibition of excessive neuroinflammation mediated by Aß is considered a promising strategy to ameliorate AD symptoms. To regulate the inflammatory response, nutritional and dietary supplements have been used for centuries. Based on this idea, we investigated whether MBN, a novel nutritional mixture including cassia bark, turmeric root, and ginkgo leaf, can prevent AD progression through neuroinflammatory regulation. METHODS: MBN (10, 30, or 100 µg/ml) and Aß1-42 monomer were incubated together, and the degree of Aß aggregation was measured using Thioflavin T assay. The effects of MBN on Aß pathology in vivo were evaluated by orally administering MBN (40 mg/kg/day for 16 weeks) to five familial AD (5xFAD) mice. RESULTS: We found that treatment with MBN inhibited Aß aggregation in vitro. Next, MBN treatment significantly inhibited the activation of microglia induced by aggregated Aß in 5xFAD mice. Caspase-1 activation, which plays an important role in the maturation of interleukin-1ß, was markedly reduced by MBN. We also found that oral administration of MBN in 5xFAD mice alleviated memory decline. Taken together, our findings demonstrate that MBN suppresses neuroinflammation by downregulating the caspase-1 expression, thereby ameliorating memory impairment in 5xFAD mice. DISCUSSION: Based on these results, we suggest that MBN may be a preventive and therapeutic supplement for AD through the regulation of neuroinflammation.

Trichosanthis Semen and Zingiberis Rhizoma Mixture Ameliorates Lipopolysaccharide-Induced Memory Dysfunction by Inhibiting Neuroinflammation.

Neuroinflammation, a key pathological contributor to various neurodegenerative diseases, is mediated by microglial activation and subsequent secretion of inflammatory cytokines via the mitogen-activated protein kinase (MAPK) signaling pathway. Moreover, neuroinflammation leads to synaptic loss and memory impairment. This study investigated the inhibitory effects of PNP001, a mixture of Trichosanthis Semen and Zingiberis Rhizoma in a ratio of 3:1, on neuroinflammation and neurological deficits induced by lipopolysaccharide (LPS). For the in vitro study, PNP001 was administered in LPS-stimulated BV2 microglial cells, and reduced the pro-inflammatory mediators, such as nitric oxide, inducible nitric oxide synthase, and cyclooxygenase-2 by downregulating MAPK signaling. For the in vivo study, ICR mice were orally administered PNP001 for 18 consecutive days, and concurrently treated with LPS (1 mg/kg, i.p.) for 10 days, beginning on the 4th day of PNP001 administration. The remarkably decreased number of activated microglial cells and increased expression of pre- and post-synaptic proteins were observed more in the hippocampus of the PNP001 administered groups than in the LPS-treated group. Furthermore, daily PNP001 administration significantly attenuated long-term memory decline compared with the LPS-treated group. Our study demonstrated that PNP001 inhibits LPS-induced neuroinflammation and its associated memory dysfunction by alleviating microglial activation and synaptic loss.

Transplantation of gut microbiota derived from Alzheimer's disease mouse model impairs memory function and neurogenesis in C57BL/6 mice.

Alzheimer's disease (AD) is a neurodegenerative disease that causes memory and cognitive decline. Although many studies have attempted to clarify the causes of AD occurrence, it is not clearly understood. Recently, the emerging role of the gut microbiota in neurodegenerative diseases, including AD, has received much attention. The gut microbiota composition of AD patients and AD mouse models is different from that of healthy controls, and these changes may affect the brain environment. However, the specific mechanisms by which gut microbiota that influence memory decline are currently unclear. In this study, we performed fecal microbiota transplantation (FMT) to clarify the role of 5xFAD mouse-derived microbiota in memory decline. We observed that FMT from 5xFAD mice into normal C57BL/6 mice (5xFAD-FMT) decreased adult hippocampal neurogenesis and brain-derived neurotrophic factor expression and increased p21 expression, resulting in memory impairment. Microglia in the hippocampus of the 5xFAD-FMT mice were activated, which caused the elevation of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-1ß). Moreover, we observed that pro-inflammatory cytokines increased in the colon and plasma of 5xFAD-FMT mice. The gut microbiota composition of the 5xFAD-FMT mice was different from that of the control mice or wild type-FMT mice. Collectively, 5xFAD mouse-derived microbiota decreased neurogenesis by increasing colonic inflammation, thereby contributing to memory loss. Our findings provide further evidence concerning the role of gut microbial dysbiosis in AD pathogenesis and suggest that targeting the gut microbiota may be a useful therapeutic strategy for the development of novel candidates for the treatment of AD.

Ginger and 6-shogaol protect intestinal tight junction and enteric dopaminergic neurons against 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine in mice.

Objective: Ginger and its compound, 6-shogaol, have been known for improving gastrointestinal (GI) function and reducing inflammatory responses in GI tract. Recently, the treatment of GI dysfunction has been recognized as an important part of the management of neurodegenerative diseases, especially for Parkinson's disease (PD). In this study, we investigated whether ginger and 6-shogaol attenuate disruptions induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the intestinal barrier and the enteric dopaminergic neurons.Methods: C57BL/6J mice received MPTP (30 mg/kg) for 5 days to induce GI alterations. Ginger (30, 100, 300 mg/kg) and 6-shogaol (10 mg/kg) were treated by gavage feeding for 15 days including the period of MPTP injection.Results: Ginger and 6-shogaol protected intestinal tight junction proteins disrupted by MPTP in mouse colon. In addition, ginger and 6-shogaol suppressed the increase of inducible nitric oxide synthase, cyclooxygenase-2, TNF-α and IL-1ß activated by macrophage. Moreover, ginger and 6-shogaol suppressed the MPTP-induced enteric dopaminergic neuronal damage via increasing the cell survival signaling pathway.Conclusion: These results indicate that ginger and 6-shogaol restore the disruption of intestinal integrity and enteric dopaminergic neurons in an MPTP-injected mouse PD model by inhibiting the processes of inflammation and apoptosis, suggesting that they may attenuate the GI dysfunction in PD patients.

Artemisiae Iwayomogii Herba Inhibits Growth, Motility, and the PI3K/AKT/mTOR Signaling Pathway in Hepatocellular Carcinoma Cells.

Artemisia gmelinii (Artemisia iwayomogi) has been used in traditional medicine to cure various infectious diseases such as cholecystitis, hepatitis, and jaundice. In this study, the Artemisiae Iwayomogii Herba ethanol extract was investigated for the ability to inhibit growth of hepatocellular carcinoma and its underlying mechanism involved. The antiproliferative effect of Artemisiae Iwayomogii Herba ethanol extract was evaluated using cell viability and proliferation assays. The effect of Artemisiae Iwayomogii Herba ethanol extract on apoptosis was measured using western blotting, terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling staining, JC-1 staining, cytochrome c release, immunohistochemistry, and immunofluorescence in ex vivo mouse xenografts. Artemisiae Iwayomogii Herba ethanol extract inhibited hepatocellular carcinoma cell growth and proliferation in a dose-dependent manner. The apoptotic effect of Artemisiae Iwayomogii Herba ethanol extract was observed via increased levels of cleaved caspase-3 and cleaved PARP, as well as elevated numbers of terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling-positive apoptotic cells. Artemisiae Iwayomogii Herba ethanol extract also decreased XIAP and Mcl-1 expression via loss of mitochondrial membrane potential. Additionally, Artemisiae Iwayomogii Herba ethanol extract inhibited hepatocellular carcinoma cell invasion and migration. In the ex vivo model, Artemisiae Iwayomogii Herba ethanol extract significantly inhibited tumor cell proliferation and increased the number of apoptotic cells with more activated cleaved caspase-3. A mechanistic study revealed that Artemisiae Iwayomogii Herba ethanol extract effectively suppressed the PI3K/AKT/mTOR signaling pathway in hepatocellular carcinoma cells. Our findings demonstrate that Artemisiae Iwayomogii Herba ethanol extract can efficiently induce apoptosis and inhibit the growth, migration, and invasion of human hepatocellular carcinoma cells, and simultaneously block PI3K/AKT/mTOR pathway. We therefore suggest Artemisiae Iwayomogii Herba ethanol extract as a novel natural agent for prevention and therapy of hepatocellular carcinoma.

Trans-Cinnamaldehyde Alleviates Amyloid-Beta Pathogenesis via the SIRT1-PGC1α-PPARγ Pathway in 5XFAD Transgenic Mice.

Abnormal amyloid-ß (Aß) accumulation is the most significant feature of Alzheimer's disease (AD). Among the several secretases involved in the generation of Aß, ß-secretase (BACE1) is the first rate-limiting enzyme in Aß production that can be utilized to prevent the development of Aß-related pathologies. Cinnamon extract, used in traditional medicine, was shown to inhibit the aggregation of tau protein and Aß aggregation. However, the effect of trans-cinnamaldehyde (TCA), the main component of cinnamon, on Aß deposition is unknown. Five-month-old 5XFAD mice were treated with TCA for eight weeks. Seven-month-old 5XFAD mice were evaluated for cognitive and spatial memory function. Brain samples collected at the conclusion of the treatment were assessed by immunofluorescence and biochemical analyses. Additional in vivo experiments were conducted to elucidate the mechanisms underlying the effect of TCA in the role of Aß deposition. TCA treatment led to improvements in cognitive impairment and reduced Aß deposition in the brains of 5XFAD mice. Interestingly, the levels of BACE1 were decreased, whereas the mRNA and protein levels of three well-known regulators of BACE1, silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC1α), and PPARγ, were increased in TCA-treated 5XFAD mice. TCA led to an improvement in AD pathology by reducing BACE1 levels through the activation of the SIRT1-PGC1α-PPARγ pathway, suggesting that TCA might be a useful therapeutic approach in AD.

Z-ligustilide and n-Butylidenephthalide Isolated from the Aerial Parts of Angelica tenuissima Inhibit Lipid Accumulation In Vitro and In Vivo.

Abnormal lipid metabolism, such as increased fatty acid uptake and esterification, is associated with nonalcoholic fatty liver disease (NAFLD). The aqueous extract of the aerial part of Angelica tenuissima Nakai (ATX) inhibited high-fat diet-induced hepatic steatosis in mice as well as oleic acid-induced neutral lipid accumulation in HepG2 cells. ATX decreased the mRNA and protein levels of CD36 and diglyceride acyltransferase 2 (DGAT2), the maturation of sterol regulatory element-binding proteins (SREBP), and the expression of the lipogenic target genes fasn and scd1. The ATX components, Z-ligustilide and n-butylidenephthalide, inhibited the expression of FATP5 and DGAT2 and thus oleic acid-induced lipid accumulation in HepG2 cells. These results suggest that ATX and its active components Z-ligustilide and n-butylidenephthalide inhibit fatty acid uptake and esterification in mice and have potential as therapeutics for NAFLD.

Protective effects of Belamcandae Rhizoma against skin damage by ameliorating ultraviolet-B-induced apoptosis and collagen degradation in keratinocytes.

Ultraviolet-B light (UV-B) is a major cause of skin photoaging, inducing cell death and extracellular matrix collapse by generating reactive oxygen species (ROS). Belamcandae Rhizoma (BR), the rhizome of Belamcanda chinensis Leman, exhibits antioxidant properties, but it remains unknown whether BR extract ameliorates UV-B-induced skin damage. In this study, we evaluated the effects of a standardized BR extract on UV-B-induced apoptosis and collagen degradation in HaCaT cells. BR was extracted using four different methods. We used radical-scavenging assays to compare the antioxidative activities of the four extracts. Cells were irradiated with UV-B and treated with BR boiled in 70% (vol/vol) ethanol (BBE). We measured cell viability, intracellular ROS levels, the expression levels of antioxidative enzymes, and apoptosis-related and collagen degradation-related proteins. The irisflorentin and tectorigenin levels were measured via high-performance liquid chromatography. BBE exhibited the best radical-scavenging and cell protective effects of the four BR extracts. BBE inhibited intracellular ROS generation and induced the synthesis of antioxidative enzymes such as catalase and glutathione. BBE attenuated apoptosis by reducing the level of caspase-3 and increasing the Bcl-2/Bax ratio. BBE reduced the level of matrix metalloproteinase-1 and increased that of type I collagen. The irisflorentin and tectorigenin contents were 0.23% and 0.015%, respectively. From these results, BBE ameliorated UV-B-induced apoptosis and collagen degradation by enhancing the expression of antioxidative enzymes. It may be a useful treatment for UV-B-induced skin damage.

Harnessing Intramolecular Rotation To Enhance Two-photon Imaging of Aß Plaques through Minimizing Background Fluorescence.

The aggregation of amyloid beta (Aß) proteins in senile plaques is a critical event during the development of Alzheimer's disease, and the postmortem detection of Aß-rich proteinaceous deposits through fluorescent staining remains one of the most robust diagnostic tools. In animal models, fluorescence imaging can be employed to follow the progression of the disease, and among the different imaging methods, two-photon microscopy (TPM) has emerged as one of the most powerful. To date, several near-infrared-emissive two-photon dyes with a high affinity for Aß fibrils have been developed, but there has often been a tradeoff between excellent two-photon cross-sections and large fluorescence signal-to-background ratios. In the current work, we introduced a twisted intramolecular charge state (TICT)-based de-excitation pathway, which results in a remarkable fluorescence increase of around 167-fold in the presence of Aß fibrils, while maintaining an excellent two-photon cross section, thereby enabling high-contrast ex vivo and in vivo TPM imaging. Overall, the results suggest that adopting TICT de-excitation in two-photon fluorophores may represent a general method to overcome the tradeoff between probe brightness and signal-to-background ratio.

A Novel and Selective p38 Mitogen-Activated Protein Kinase Inhibitor Attenuates LPS-Induced Neuroinflammation in BV2 Microglia and a Mouse Model.

Neuroinflammation is an important pathological feature in neurodegenerative diseases. Accumulating evidence has suggested that neuroinflammation is mainly aggravated by activated microglia, which are macrophage like cells in the central nervous system. Therefore, the inhibition of microglial activation may be considered for treating neuroinflammatory diseases. p38 mitogen-activated protein kinase (MAPK) has been identified as a crucial enzyme with inflammatory roles in several immune cells, and its activation also relates to neuroinflammation. Considering the proinflammatory roles of p38 MAPK, its inhibitors can be potential therapeutic agents for neurodegenerative diseases relating to neuroinflammation initiated by microglia activation. This study was designed to evaluate whether NJK14047, a recently identified novel and selective p38 MAPK inhibitor, could modulate microglia-mediated neuroinflammation by utilizing lipopolysaccharide (LPS)-stimulated BV2 cells and an LPS-injected mice model. Our results showed that NJK14047 markedly reduced the production of nitric oxide and prostaglandin E2 by downregulating the expression of various proinflammatory mediators such as nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α and interleukin-1ß in LPS-induced BV2 microglia. Moreover, NJK14047 significantly reduced microglial activation in the brains of LPS-injected mice. Overall, these results suggest that NJK14047 significantly reduces neuroinflammation in cellular/vivo model and would be a therapeutic candidate for various neuroinflammatory diseases.

Piperlongumine inhibits neuroinflammation via regulating NF-κB signaling pathways in lipopolysaccharide-stimulated BV2 microglia cells.

Inflammatory processes in the central nervous system are feature among biological reactions to harmful stimuli such as pathogens and damaged cells. In resting conditions, microglia are involved in immune surveillance and brain homeostasis. However, the activation of abnormal microglia can be detrimental to neurons, even resulting in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Therefore, normalization of microglial activation is considered a promising strategy for developing drugs that can treat or prevent inflammation-related brain diseases. In the present study, we investigated the effects of piperlongumine, an active component of Piper longum, on lipopolysaccharide (LPS)-induced neuroinflammation using BV2 microglial cells. We found that piperlongumine significantly inhibited the production of nitric oxide and prostaglandin E2 induced by LPS. Piperlongumine also reduced the expression of inducible nitric oxide synthase and cyclooxygenase-2 as well as proinflammatory cytokines such as tumor necrosis factor-α and interleukin-6. Piperlongumine exerted its anti-neuroinflammatory effects by suppressing the nuclear factor kappa B signaling pathway. These findings suggest that piperlongumine could be a candidate agent for the treatment of inflammation-related neurodegenerative diseases.

Artemisia Capillaris leaves inhibit cell proliferation and induce apoptosis in hepatocellular carcinoma.

BACKGROUND: Natural product is one of the most important sources of drugs used in pharmaceutical therapeutics. Artemisia capillaris has been traditionally used as a hepatoprotective and anti-inflammatory agent. In this study, we extracted an ethanol fraction (LAC117) from the dried leaves of Artemisia capillaris and identified its anticancer activity and mechanism of action against hepatocellular carcinoma (HCC). METHODS: Anti-proliferative effect of LAC117 was evaluated by MTT assay and BrdU assay. The apoptotic effect of LAC117 on the expression of cleaved PARP and cleaved caspase-3 was evaluated by Western blot and immunohistochemistry from in vivo mouse xenograft, respectively. RESULTS: We found that LAC117 strongly suppressed the growth and proliferation of human HCC cell lines (HepG2 and Huh7). Induction of apoptosis was evidenced by the increases of cleaved caspase-3 and PARP as well as TUNEL-positive cells. Additionally, the pro-apoptotic effect of LAC117 was observed by a decrease in the expression of the XIAP and an increase in cytochrome c releases via mitochondrial membrane potential. Moreover, it significantly inhibited PI3K/AKT pathway in HCC in vivo and in vitro. LAC117 suppressed tumor growth in an ex vivo model as well as in vivo mouse xenograft by inducing apoptosis and inhibiting tumor cell proliferation. CONCLUSIONS: The present study highlights that LAC117 could not only efficiently induce apoptosis, but also inhibit the growth of human HCC cells by blocking the PI3K/AKT signaling pathway, suggesting that LAC117 would be a potentially useful drug candidate against HCC.

An ethyl acetate fraction of Artemisia capillaris (ACE-63) induced apoptosis and anti-angiogenesis via inhibition of PI3K/AKT signaling in hepatocellular carcinoma.

In cancer treatment, herbal medicines may be a good choice because of the reduced risk of adverse side effects. Artemisia capillaris has been recognized as a promising candidate due to its hepatoprotective effects. Herein, we investigated whether A. capillaris-derived fraction (ACE-63) could inhibit the progression of hepatocellular carcinoma (HCC) and its underlying mechanism. In this study, ACE-63 effectively inhibited the growth and proliferation of HCC cells. ACE-63 induced apoptosis, as observed using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, which was accompanied with increases in cleaved Poly (ADP-ribose) polymerase (PARP) and caspase-3 in HCC cells. Additionally, the pro-apoptotic effect of ACE-63 was demonstrated by a decrease in the expression of the X-linked inhibitor of apoptosis protein (XIAP) and survivin via a loss of mitochondrial membrane potential. In an ex vivo model, ACE-63 significantly inhibited tumor cell growth and induced apoptosis by increasing the expression of cleaved caspase-3 and DNA fragmentation. In addition, ACE-63 decreased the expression of hypoxia-inducible factor-1α and vascular endothelial growth factor and inhibited tube formation of human umbilical vein endothelial cells. A mechanistic study revealed that ACE-63 effectively suppressed the PI3K/AKT/mTOR signaling pathways, which were observed as a target signaling by phosphokinase array. Taken together, our findings demonstrate that ACE-63 could not only efficiently induce apoptosis but also inhibit the growth/angiogenesis of human HCC cells by blocking the PI3K/AKT/mTOR signaling pathway, suggesting that ACE-63 may be a new chemotherapeutic candidate against HCC.

Effects of Rhei Undulati Rhizoma on lipopolysaccharide-induced neuroinflammation in vitro and in vivo.

Neuroinflammation plays a critical role in the pathogenesis of degenerative brain diseases such as Alzheimer's disease and Parkinson's disease. Microglia are the major components of the brain immune system that regulate inflammatory processes. Activated microglia release pro-inflammatory factors and cytokines, resulting in neuronal cell death. We focused on inhibiting the activation of microglia from a stimulus as a strategy to search for neuroprotective drugs. Rhei Undulati Rhizoma (RUR) is traditionally used to treat various inflammatory disorders. In this study, we investigated whether RUR modulates inflammatory processes in lipopolysaccharide (LPS)-stimulated BV2 microglia cells and the mouse brain. RUR exerted anti-neuroinflammatory effects by inhibiting the production of nitric oxide and reactive oxygen species induced by LPS via the downregulation of transcription factors such as inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) without causing cytotoxicity. RUR also regulated mitogen-activated protein kinase pathway by inhibiting phosphorylation of p38 and c-Jun N-terminal kinases and translocation of nuclear factor kappa B. Moreover, RUR attenuated LPS-induced glial activation and COX-2 expression in the substantia nigra and hippocampus of the mouse brain. These results indicate that RUR is a potential candidate to treat neurodegenerative diseases by regulating neuroinflammation.

Butterbur Leaves Attenuate Memory Impairment and Neuronal Cell Damage in Amyloid Beta-Induced Alzheimer's Disease Models.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, and is characterized by the accumulation of amyloid beta (Aß) as a pathological hallmark. Aß plays a central role in neuronal degeneration and synaptic dysfunction through the generation of excessive oxidative stress. In the present study, we explored whether leaves of Petasites japonicus (Siebold & Zucc.) Maxim. (PL), called butterbur and traditionally used in folk medicine, show neuroprotective action against Aß25⁻35 plaque neurotoxicity in vitro and in vivo. We found that PL protected Aß25⁻35 plaque-induced neuronal cell death and intracellular reactive oxygen species generation in HT22 cells by elevating expression levels of phosphorylated cyclic AMP response element-binding protein, heme oxygenase-1, and NAD(P)H quinine dehydrogenase 1. These neuroprotective effects of PL were also observed in Aß25⁻35 plaque-injected AD mouse models. Moreover, administration of PL diminished Aß25⁻35 plaque-induced synaptic dysfunction and memory impairment in mice. These findings lead us to suggest that PL can protect neurons against Aß25⁻35 plaque-induced neurotoxicity and thus may be a potential candidate to regulate the progression of AD.

Dangguijakyak-san ameliorates memory deficits in ovariectomized mice by upregulating hippocampal estrogen synthesis.

BACKGROUND: Dangguijakyak-san (DJS) is an herbal formulation that has been clinically applicable for treating postmenopausal symptoms and neurological disorders. It is reported that hippocampal estrogen attenuates memory impairment via neuroprotection and synaptogenesis. However, the effect of DJS on hippocampal estrogen synthesis remains unknown. In this study, we explored the effect of DJS and its neuroprotective mechanism against memory impairment in ovariectomized (OVX) mice, with respect to hippocampal estrogen stimulation. METHODS: Cell cultures were prepared from the hippocampi of 18-day-old embryos from timed pregnant Sprague-Dawley rats. The hippocampi were dissected, collected, dissociated, and plated in 60-mm dishes. The cells were treated with DJS for 48 h and the supernatant was collected to determine estrogen levels. Female ICR mice (8-weeks-old) were housed for 1 week and ovariectomy was performed to remove the influence of ovary-synthesized estrogens. Following a 2-week post-surgical recovery period, the mice were administrated with DJS (50 and 100 mg/kg/day, p.o.) or 17ß-estradiol (200 µg/kg/day, i.p.) once daily for 21 days. Hippocampal and serum estrogen levels were determined using enzyme-linked immunosorbent assay kit. Memory behavioral tests, western blot, and immunohistochemical analyses were performed to evaluate the neuroprotective effects of DJS in this model. RESULTS: DJS treatment promoted estrogen synthesis in primary hippocampal cells and the hippocampus of OVX mice, resulting in the amelioration of OVX-induced memory impairment. Hippocampal estrogen stimulated by DJS treatment contributed to the activation of cAMP response element-binding protein and synaptic protein in OVX mice. CONCLUSION: DJS may attenuate memory deficits in postmenopausal women via hippocampal estrogen synthesis.