The Effect of Dual Bioactive Compounds Artemisinin and Metformin Co-loaded in PLGA-PEG Nano-particles on Breast Cancer Cell lines: Potential Apoptotic and Anti-proliferative Action.

The most prevalent malignancy among women is breast cancer. Phytochemicals and their derivatives are rapidly being recognized as possible cancer complementary therapies because they can modify signaling pathways that lead to cell cycle control or directly alter cell cycle regulatory molecules. The phytochemicals' poor bioavailability and short half-life make them unsuitable as anticancer drugs. Applying PLGA-PEG NPs improves their solubility and tolerance while also reducing drug adverse effects. According to the findings, combining anti-tumor phytochemicals can be more effective in regulating several signaling pathways linked to tumor cell development. The point of the study was to compare the anti-proliferative impacts of combined artemisinin and metformin on cell cycle arrest and expression of cyclin D1 and apoptotic genes (bcl-2, Bax, survivin, caspase-7, and caspase-3), and also hTERT genes in breast cancer cells. T-47D breast cancer cells were treated with different concentrations of metformin (MET) and artemisinin (ART) co-loaded in PLGA-PEG NPs and free form. The MTT test was applied to assess drug cytotoxicity in T47D cells. The cell cycle distribution was investigated using flow cytometry and the expression levels of cyclin D1, hTERT, Bax, bcl-2, caspase-3, and caspase-7, and survivin genes were then determined using real-time PCR. The findings of the MTT test and flow cytometry revealed that each state was cytotoxic to T47D cells in a time and dose-dependent pattern. Compared to various state of drugs (free and nano state, pure and combination state) Met-Art-PLGA/PEG NPs demonstrated the strongest anti-proliferative impact and considerably inhibited the development of T-47D cells; also, treatment with nano-formulated forms of Met-Art combination resulted in substantial downregulation of hTERT, Bcl-2, cyclin D1, survivin, and upregulation of caspase-3, caspase-7, and Bax, in the cells, as compared to the free forms, as indicated by real-time PCR findings. The findings suggested that combining an ART/MET-loaded PLGA-PEG NP-based therapy for breast cancer could significantly improve treatment effectiveness.

Neuroprotective effect of Geijigadaehwang-tang against trimethyltin-induced hippocampal neurodegeneration: An in vitro and in vivo study.

ETHNOPHARMACOLOGICAL RELEVANCE: Patients with dementia are diagnosed with deficiency patterns and interior patterns in traditional Chinese medicine due to decreased physical strength, mental atrophy including cognitive function, and decreased motor function in the gastrointestinal tract. Since "greater yin symptom" in Shanghanlun has been interpreted as interior, deficiency, and cold pattern in traditional Chinese medicine, it is necessary to determine whether Geijigadaehwang-tang (GDT) has therapeutic effects on neurodegenerative diseases and the underlying mechanism if it has such effects. AIMS OF THE STUDY: Trimethyltin (TMT), a neurotoxic organotin compound, has been used to induce several neurodegenerative diseases, including epilepsy and Alzheimer's disease. This study aimed to evaluate the therapeutic efficacy of GDT for TMT-induced hippocampal neurodegeneration and seizures and to determine the mechanisms involved at the molecular level. MATERIALS AND METHODS: The main components of GDT were analyzed using ultra-performance liquid chromatography. TMT was used to induce neurotoxicity in microglial BV-2 cells and C57BL6 mice. GDT was administered at various doses to determine its neuroprotective and seizure inhibition effects. The inhibitory effects of GDT on TMT-induced apoptosis, inflammatory pathways, and oxidative stress pathways were determined in the mouse hippocampal tissues. RESULTS: GDT contained emodin, chrysophanol, albiflorin, paeoniflorin, 6-gingerol, and liquiritin apioside. In microglial BV-2 cells treated with TMT, GDT showed dose-dependent neuroprotective effects. Oral administration of GDT five times for 2.5 days before and after TMT injection inhibited seizures at doses of 180 and 540 mg/kg and inhibited neuronal death in the hippocampus. In hippocampal tissues extracted from mice, GDT inhibited the protein expression of ionized calcium binding adaptor molecule 1, glial fibrillary acidic protein, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3, and phosphorylated nuclear factor (NF)-κB/total-NFκB ratio. Additionally, GDT inhibited the messenger RNA levels of tumor necrosis factor-α, inducible nitric oxide synthase, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interleukin-1ß, nuclear factor erythroid-2-related factor 2, and heme oxygenase-1. CONCLUSION: This study's results imply that GDT might have neuroprotective potential in neurodegenerative diseases through neuronal death inhibition and anti-inflammatory and antioxidant mechanisms.

Sinomenine Attenuates Trimethyltin-Induced Cognitive Decline via Targeting Hippocampal Oxidative Stress and Neuroinflammation.

Sinomenine is the main bioactive ingredient of the medicinal plant Sinomenium acutum with neuroprotective potential. This study was designed to assess beneficial effect of sinomenine in alleviation of trimethyltin (TMT)-induced cognitive dysfunction. TMT was administered i.p. (8 mg/kg, once) and sinomenine was daily given p.o. 1 h after TMT for 3 weeks at doses of 25 or 100 mg/kg. Cognitive performance was assessed in various behavioral tests. In addition, oxidative stress- and inflammation-associated factors were measured and histochemical evaluation of the hippocampus was conducted. Sinomenine at a dose of 100 mg/kg significantly and partially increased discrimination index in novel object recognition (NOR), improved alternation in short-term Y maze, increased step-through latency in passive avoidance paradigm, and also reduced probe trial errors and latency in the Barnes maze task. Moreover, sinomenine somewhat prevented inappropriate hippocampal changes of malondialdehyde (MDA), reactive oxygen species (ROS), protein carbonyl, nitrite, superoxide dismutase (SOD), tumor necrosis factor α (TNFα), interleukin 6 (IL 6), acetylcholinesterase (AChE) activity, beta secretase 1 (BACE 1) activity, and mitochondrial membrane potential (MMP) with no significant effect on glutathione (GSH), catalase, glutathione reductase, glutathione peroxidase, and myeloperoxidase (MPO). In addition, lower reactivity (IRA) for glial fibrillary acidic protein (GFAP) as an index of astrocyte activity was observed and loss of CA1 pyramidal neurons was attenuated following sinomenine treatment. This study demonstrated that sinomenine could lessen TMT-induced cognitive dysfunction which is partly due to its attenuation of hippocampal oxidative stress and neuroinflammation.

Acute Trimethyltin Poisoning Caused by Exposure to Polyvinyl Chloride Production: 8 Cases.

This manuscript aimed to describe and analyze acute trimethyltin poisoning caused by exposure to polyvinyl chloride production and review the literature. Combined with an analysis of occupational hygiene survey data, the clinical data of 8 cases of acute trimethyltin poisoning were analyzed retrospectively. The clinical manifestations of acute trimethyltin poisoning are mainly related to central nervous system damage, hypokalemia and metabolic acidosis in patients with severe poisoning. Early positive potassium supplementation and symptomatic treatment are beneficial to the improvement of the condition. The early recognition of central nervous system manifestations and hypokalemia is beneficial for early diagnosis and correct treatment.

Bacopa monnieri (L.) Wettst. Extract Improves Memory Performance via Promotion of Neurogenesis in the Hippocampal Dentate Gyrus of Adolescent Mice.

Bacopa monnieri L. Wettst. (BM) is a botanical component of Ayurvedic medicines and of dietary supplements used worldwide for cognitive health and function. We previously reported that administration of BM alcoholic extract (BME) prevents trimethyltin (TMT)-induced cognitive deficits and hippocampal cell damage and promotes TMT-induced hippocampal neurogenesis. In this study, we demonstrate that administration of BME improves spatial working memory in adolescent (5-week- old) healthy mice but not adult (8-week-old) mice. Moreover, improved spatial working memory was retained even at 4 weeks after terminating 1-week treatment of adolescent mice. One-week BME treatment of adolescent mice significantly enhanced hippocampal BrdU incorporation and expression of genes involved in neurogenesis determined by RNAseq analysis. Cell death, as detected by histochemistry, appeared not to be significant. A significant increase in neurogenesis was observed in the dentate gyrus region 4 weeks after terminating 1-week treatment of adolescent mice with BME. Bacopaside I, an active component of BME, promoted the proliferation of neural progenitor cells in vitro in a concentration-dependent manner via the facilitation of the Akt and ERK1/2 signaling. These results suggest that BME enhances spatial working memory in healthy adolescent mice by promoting hippocampal neurogenesis and that the effects of BME are due, in significant amounts, to bacopaside I.

Bacopa monnieri (L.) Ameliorates Cognitive Deficits Caused in a Trimethyltin-Induced Neurotoxicity Model Mice.

We previously demonstrated that Bacopa monnier (L.) WETTST. extract (BME) ameliorated cognitive dysfunction in animal models of dementia by enhancing synaptic plasticity-related signaling in the hippocampus and protecting cholinergic neurons in the medial septum. To further clarify the pharmacological features and availability of BME as a novel anti-dementia agent, we investigated whether BME affects neuronal repair using a mouse model of trimethyltin (TMT)-induced neuronal loss/self-repair in the hippocampus. Mice pretreated with TMT (2.8 mg/kg, intraperitoneally (i.p.)) on day 0 were given BME (50 mg/kg, per os (p.o.)) once daily for 15-30 d. Cognitive performance of the animals was elucidated twice by the object location test and modified Y maze test on days 17-20 (Phase I) and days 32-35 (Phase II) or by the passive avoidance test on Phase II. TMT impaired hippocampus-dependent spatial working memory and amygdala-dependent fear-motivated memory. The administration of BME significantly prevented TMT-induced cognitive deficits. The protective effects of BME on the spatial memory deficits were confirmed by Nissl staining of hippocampal tissues and propidium iodide staining of organotypic hippocampal slice cultures. Immunohistochemical studies conducted on days 17 and 32 revealed that thirty days of treatment with BME increased the number of 5-bromo-2'-deoxyuridine (BrdU)-immunopositive cells in the dentate gyrus region of TMT-treated mice, whereas fifteen days of treatment with BME had no effect. These results suggest that BME ameliorates TMT-induced cognition dysfunction mainly via protecting the hippocampal neurons from TMT-induced hippocampal lesions and partly via promoting neuroregeneration in the dentate gyrus regions.

The neuroprotective effects of an ethanolic turmeric (Curcuma longa L.) extract against trimethyltin-induced oxidative stress in rats.

Introduction: Oxidative stress is known to contribute to the pathogenesis of neurodegenerative disorders. An ethanolic turmeric (Curcuma longa L.) extract containing curcumin has been reported to produce antioxidant effects. Objective: The present study aims to investigate the possible neuroprotective effects of the ethanolic turmeric extract against trimethyltin (TMT)-induced oxidative stress in Sprague Dawley rats. Methods: The ethanolic turmeric extract and citicoline were administered to the TMT exposed rats from day 1 to day 28 of the experiment. The TMT injection was administered on day 8 of the experiment. The plasma and brain malondialdehyde (MDA) and reduced glutathione (GSH) levels, and the activities of the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzymes in the brain were examined at the end of the experiment. Results: The administration of 200 mg/kg bw of the ethanolic turmeric extract prevented oxidative stress by decreasing the plasma and brain MDA levels and increasing the SOD, CAT, and GPx enzyme activities and GSH levels in the brain. These effects seem to be comparable to those of citicoline. Discussion: The ethanolic turmeric extract at a dose of 200 mg/kg bw may exert neuroprotective effects on TMT-exposed Sprague Dawley rats by preventing them from oxidative stress.

Ginsenoside Rg3 and Rh2 protect trimethyltin-induced neurotoxicity via prevention on neuronal apoptosis and neuroinflammation.

The acute exposure of trimethyltin (TMT) develops clinical syndrome characterized by amnesia, aggressive behavior, and complex seizures. This neurotoxicant selectively induces hippocampal neuronal injury and glial activation accompanied with resultant neuroinflammation. Here we report two candidates ginsenosides Rg3 and Rh2 as neuroprotection agents using a mouse model of TMT intoxication via a single injection (2 mg/kg) and primary neuronal culture systems. Four-week administration of Rg3 or Rh2 significantly reduced TMT-induced seizures and behavioral changes. Rg3 and Rh2 significantly attenuated the oxidative stress evidenced by improvement on antioxidant enzymes and neuronal loss and astrocytic activation in mouse brain. In primary cultures, TMT induced significant neuronal death after 24-h intoxication and vigorous secretion of inflammatory cytokines (IL-1α/ß, IL-6, TNF-α, and MCP-1) in astrocytes. Pretreatment with Rg3 or Rh2 not only reduced cell death but efficiently suppressed above mentioned inflammatory cytokines confirmed by antibody array test. The underlying protective mechanism by Rg3 and Rh2 was delineated through selective upregulation of PI3K/Akt and suppression of ERK activation. Intriguingly, Rg3 and Rh2 protected oligodendrocyte progenitor cells (O-2A) from TMT intoxication via promoting type 2 astrocytic differentiation without further inflammatory activation. Collectively, Rg3 and Rh2 interventions aimed at reducing oxidative stress and neuroinflammation neurotoxicity therefore are of therapeutic benefit in TMT-induced neurodegeneration.

Erucamide from Radish Leaves Has an Inhibitory Effect Against Acetylcholinesterase and Prevents Memory Deficit Induced by Trimethyltin.

In this study, we investigated a potent acetylcholinesterase inhibitor that was isolated from radish leaf (Raphanus sativus L.) extracts. Through sequential fractionation of radish leaf extract, the active constituent was identified as cis-13-docosenamide (erucamide). To validate the potency, erucamide derived from radish leaves was supplemented in diets and then fed to trimethyltin (TMT)-exposed mice. Specifically, mice had free access to a control diet or diets containing different concentrations of erucamide for 3 weeks, followed by an injection of TMT (2.5 mg/kg body weight). Our results showed that pretreatment of mice with erucamide (20 and 40 mg/kg body weight per day) significantly attenuated the TMT-induced learning and memory deficits that were assessed by Y-maze and passive avoidance tests. These findings suggest that radish leaves, and possibly its isolated erucamide, may have preventive effects against memory deficits related to Alzheimer's disease by modulation of cholinergic functions.

Turmeric (Curcuma longa L.) extract may prevent the deterioration of spatial memory and the deficit of estimated total number of hippocampal pyramidal cells of trimethyltin-exposed rats.

CONTEXT: Protection of neurons from degeneration is an important preventive strategy for dementia. Much of the dementia pathology implicates oxidative stress pathways. Turmeric (Curcuma longa L.) contains curcuminoids which has anti-oxidative and neuro-protective effects. These effects are considered to be similar to those of citicoline which has been regularly used as one of standard medications for dementia. OBJECTIVE: This study aimed at investigating the effects of turmeric rhizome extract on the hippocampus of trimethyltin (TMT)-treated Sprague-Dawley rats. MATERIALS AND METHODS: The rats were divided randomly into six groups, i.e., a normal control group (N); Sn group, which was given TMT chloride; Sn-Cit group, which was treated with citicoline and TMT chloride; and three Sn-TE groups, which were treated with three different dosages of turmeric rhizome extract and TMT chloride. Morris water maze test was carried out to examine the spatial memory. The estimated total number of CA1 and CA2-CA3 pyramidal cells was calculated using a stereological method. RESULTS: The administration of turmeric extract at a dose of 200 mg/kg bw has been shown to prevent the deficits in the spatial memory performance and partially inhibit the reduction of the number of CA2-CA3 regions pyramidal neurons. DISCUSSION: TMT-induced neurotoxic damage seemed to be mediated by the generation of reactive oxygen species and reactive nitrogen species. Turmeric extract might act as anti inflammatory as well as anti-oxidant agent. CONCLUSIONS: The effects of turmeric extract at a dose of 200 mg/kg bw seem to be comparable to those of citicoline.

Anti-inflammatory effects of Ginkgo biloba extract against trimethyltin-induced hippocampal neuronal injury.

BACKGROUND: Despite the immense neuromodulatory potentials of Ginkgo biloba extract as a memory enhancer, its underlying mechanism seems inadequate particularly with regard to its anti-inflammatory properties. AIM: The objective of the present study is to investigate the protective potentials of Ginkgo biloba extract (GBE) against hippocampal neuronal injury induced by trimethyltin (TMT), a potent neurotoxicant. METHODS: Male SD rats were administered trimethyltin (8.5 mg kg-1 b.wt) single intraperitoneal (i.p.) injection, followed by Ginkgo biloba extract (100 mg kg-1 b.wt i.p) for 21 days. RESULTS: The co-administration of GBE with TMT showed marked improvement in cognitive functions. Concomitantly, there was a significant decrease in oxidative stress as evident by reduction in MDA and total ROS levels. In addition, there was a marked suppression of astrocyte activation (GFAP), transcription factor NFκB and proinflammatory cytokines (TNF-α, IL-1α, 1L-6), which were found to be elevated by TMT administration. Histopathological observations showed remarkable improvement in hippocampal neuronal injury in the conjunctive group. CONCLUSION: Therefore, it is suggested that Ginkgo biloba extract is an effective agent against trimethyltin-induced hippocampal neuronal loss owing to its antioxidative as well as anti-inflammatory properties.

Ginsenoside Re Protects Trimethyltin-Induced Neurotoxicity via Activation of IL-6-Mediated Phosphoinositol 3-Kinase/Akt Signaling in Mice.

Ginseng (Panax ginseng), an herbal medicine, has been used to prevent neurodegenerative disorders. Ginsenosides (e.g., Re, Rb1, or Rg1) were obtained from Korean mountain cultivated ginseng. The anticonvulsant activity of ginsenoside Re (20 mg/kg/day × 3) against trimethyltin (TMT) insult was the most pronounced out of ginsenosides (e.g., Re, Rb1, and Rg1). Re itself did not significantly alter tumor necrosis factor-α (TNF-α), interferon-ϒ (IFN-ϒ), and interleukin-1ß (IL-1ß) expression, however, it significantly increases the interleukin-6 (IL-6) expression. In addition, Re attenuated the TMT-induced decreases in IL-6 protein level. Therefore, IL-6 knockout (-/-) mice were employed to investigate whether Re requires IL-6-dependent neuroprotective activity against TMT toxicity. Re significantly attenuated TMT-induced lipid peroxidation, protein peroxidation, and reactive oxygen species in the hippocampus. Re-mediated antioxidant effects were more pronounced in IL-6 (-/-) mice than in WT mice. Consistently, TMT-induced increase in c-Fos-immunoreactivity (c-Fos-IR), TUNEL-positive cells, and nuclear chromatin clumping in the dentate gyrus of the hippocampus were significantly attenuated by Re. Furthermore, Re attenuated TMT-induced proapoptotic changes. Protective potentials by Re were comparable to those by recombinant IL-6 protein (rIL-6) against TMT-insult in IL-6 (-/-) mice. Moreover, treatment with a phosphoinositol 3-kinase (PI3K) inhibitor, LY294002 (1.6 µg, i.c.v) counteracted the protective potential mediated by Re or rIL-6 against TMT insult. The results suggest that ginsenoside Re requires IL-6-dependent PI3K/Akt signaling for its protective potential against TMT-induced neurotoxicity.

Treatment with Mountain-Cultivated Ginseng Alleviates Trimethyltin-Induced Cognitive Impairments in Mice via IL-6-Dependent JAK2/STAT3/ERK Signaling.

Panax ginseng is the most widely used herbal medicine for improving cognitive functions. The pharmacological activity and underlying mechanisms of mountain-cultivated ginseng, however, have yet to be clearly elucidated, in particular, against trimethyltin-induced cognitive dysfunction. We previously reported that interleukin-6 plays a protective role against trimethyltin-induced cognitive dysfunction. Because of this, we have implemented a study system that uses interleukin-6 null (-/-) and wild-type mice. Interestingly, mountain-cultivated ginseng significantly upregulated interleukin-6 expression. With this study, we sought to determine whether the interleukin-6-dependent modulation of the Janus kinase 2/signal transducer activator of transcription 3 and extracellular signal-regulated kinase signaling network is also associated with the pharmacological activity of mountain-cultivated ginseng against trimethyltin-induced cognitive dysfunction. Trimethyltin treatment (2.4 mg/kg, intraperitoneal) causes the downregulation of Janus kinase 2/signal transducer activator of transcription 3, extracellular signal-regulated kinase signaling, and impairment of the cholinergic system. We found that mountain-cultivated ginseng treatment (50 mg/kg, intraperitoneal) significantly attenuated cognitive impairment normally induced by trimethyltin by upregulating p-Janus kinase 2/signal transducer activator of transcription 3, p-extracellular signal-regulated kinase signaling, and the cholinergic system. Trimethyltin-induced cognitive impairments were more pronounced in interleukin-6 (-/-) mice than wild-type mice, and they were markedly reduced by treatment with either mountain-cultivated ginseng or recombinant interleukin-6 protein (6 ng, intracerebroventricular). Additionally, treatment with either AG490 (20 mg/kg, intraperitoneal), a Janus kinase 2/signal transducer activator of transcription 3 inhibitor, or U0126 (2 µg/head, intracerebroventricular), an extracellular signal-regulated kinase inhibitor, reversed the effects of mountain-cultivated ginseng treatment. The effects of mountain-cultivated ginseng treatment were comparable to those of recombinant interleukin-6 protein in interleukin-6 (-/-) mice. Our results, therefore, suggest that mountain-cultivated ginseng acts through interleukin-6-dependent activation of Janus kinase 2/signal transducer activator of transcription 3/extracellular signal-regulated kinase signaling in order to reverse cognitive impairment caused by trimethyltin treatment.

Turmeric extract inhibits apoptosis of hippocampal neurons of trimethyltin-exposed rats.

OBJECTIVES: The aim of the present study was to reveal the possible antiapoptotic effect of turmeric (Curcuma longa Linn.) on the hippocampal neurons of rats exposed to trimethyltin (TMT). BACKGROUND: Oxidative damage in the hippocampus can induce the apoptosis of neurons associated with the pathogenesis of dementiaMETHODS. The ethanolic turmeric extract and a citicoline (as positive control) solution were administered to the TMT-exposed rats for 28 days. The body weights of rats were recorded once a week. The hippocampal weights and imumunohistochemical expression of caspase 3 proteins in the CA1 and CA2-CA3 regions of the hippocampi were examined at the end of the experiment. RESULTS: Immunohistochemical analysis showed that the injection of TMT increased the expression of caspase 3 in the CA1 and CA2-CA3 regions of hippocampus. TMT also decreased the body and hippocampal weights. Furthermore, the administration of 200 mg/kg bw dose of turmeric extract decreased the caspase 3 expression in the CA2-CA3 pyramidal neurons but not in the CA1 neurons. It also prevented the decrease of the body and hippocampal weights. CONCLUSION: We suggest that the 200 mg/kg bw dose of turmeric extract may exert antiapoptotic effect on the hippocampal neurons of the TMT-exposed rats (Tab. 1, Fig. 3, Ref. 49).

Cinnamomum loureirii Extract Inhibits Acetylcholinesterase Activity and Ameliorates Trimethyltin-Induced Cognitive Dysfunction in Mice.

The pathogenesis of Alzheimer's disease (AD) has been linked to the deficiency of neurotransmitter acetylcholine (ACh) in the brain, and the main treatment strategy for improving AD symptoms is the inhibition of acetylcholinesterase (AChE) activity. In the present study, we aimed to identify potent AChE inhibitors from Cinnamomum loureirii extract via bioassay-guided fractionation. We demonstrated that the most potent AChE inhibitor present in the C. loureirii extract was 2,4-bis(1,1-dimethylethyl)phenol. To confirm the antiamnesic effects of the ethanol extract of C. loureirii, mice were intraperitoneally injected with the neurotoxin trimethyltin (2.5 mg/kg) to induce cognitive dysfunction, and performance in the Y-maze and passive avoidance tests was assessed. Treatment with C. loureirii extract significantly improved performance in both behavioral tests, suggesting that this extract may be neuroprotective and therefore beneficial in preventing or ameliorating the degenerative processes of AD, potentially by restoring cholinergic function.

Lycium barbarum Polysaccharides Protect against Trimethyltin Chloride-Induced Apoptosis via Sonic Hedgehog and PI3K/Akt Signaling Pathways in Mouse Neuro-2a Cells.

Trimethyltin chloride (TMT) is a classic neurotoxicant that can cause severe neurodegenerative diseases. Some signaling pathways involving cell death play pivotal roles in the central nervous system. In this study, the role of Sonic Hedgehog (Shh) and PI3K/Akt pathways in TMT-induced apoptosis and protective effect of Lycium barbarum polysaccharides (LBP) on mouse neuro-2a (N2a) cells were investigated. Results showed that TMT treatment significantly enhanced apoptosis, upregulated proapoptotic Bax, downregulated antiapoptotic Bcl-2 expression, and increased caspase-3 activity in a dose-dependent manner in N2a cells. TMT induced oxidative stress in cells, performing reactive oxygen species (ROS) and malondialdehyde (MDA) excessive generation, and superoxide dismutase (SOD) activity reduction. TMT significantly decreased phosphorylated glycogen synthase kinase-3ß (GSK-3ß) and inhibited Shh and PI3K/Akt pathways. However, the addition of LBP upregulated GSK-3ß phosphorylation, activated Shh and PI3K/Akt pathways, and eventually reduced apoptosis and oxidative stress caused by TMT. The interaction between Shh and PI3K/Akt pathways was clarified by specific PI3K inhibitor LY294002 or Shh inhibitor GDC-0449. Moreover, LY294002 and GDC-0449 pretreatment both induced phosphorylated GSK-3ß downregulation and significantly promoted apoptosis induced by TMT. These results suggest that LBP could reduce TMT-induced N2a cells apoptosis by regulating GSK-3ß phosphorylation, Shh, and PI3K/Akt signaling pathways.

Perilla frutescens Extract Ameliorates Acetylcholinesterase and Trimethyltin Chloride-Induced Neurotoxicity.

One of the critical features of Alzheimer's disease is cognitive dysfunction, which is, in part, due to decreases in acetylcholine (ACh). The ethanol extract of Perilla frutescens was selected for isolating the acetylcholinesterase (AChE) inhibitor based on preliminary screening. In vivo behavioral tests were performed to examine the effects of the P. frutescens extract on trimethyltin chloride-induced impairment of learning and memory in mice. A diet containing P. frutescens extract effectively reversed learning and memory impairment on the Y-maze and passive avoidance tests. To isolate the active compound from the P. frutescens extract, solvent partitioning, silica gel open column chromatography, thin-layer chromatography, and high-performance liquid chromatography were used. The AChE inhibitor was identified as rosmarinic acid.

Neuroprotective effects of fermented soybean products (Cheonggukjang) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on trimethyltin-induced cognitive defects mice.

OBJECTIVES: This study aimed to investigate the beneficial effects of Cheonggukjang (CGK) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on neurotoxic damages. METHODS: The specific aspects of brain functions were measured in Institute for Cancer Research (ICR) mice that had been pretreated for 4 weeks with three difference doses of CGK before trimethyltin (TMT) treatment. RESULTS: The short- and long-term memory loss induced by TMT treatment was significantly improved in the CGK-pretreated group in a dose-dependent manner. The number of dead cells in the granule cell layer of the dentate gyrus was decreased in the TMT/CGK-cotreated group relative to the TMT/vehicle-treated group, whereas significant suppression of acetylcholinesterase (AChE) activity was observed in the same group. Additionally, a dose-dependent increase in nerve growth factor (NGF) concentration, activation of the NGF receptor signaling pathway including the TrkA high affinity receptor and p75(NTR) low affinity receptor, and decline in Bax/Bcl-2 level was measured in all TMT/CGK-treated groups, although a decrease in the active form of caspase-3 was observed in the TMT/H-CGK-treated group. Furthermore, superoxide dismutase (SOD) activity was enhanced in the TMT/CGK-treated group, whereas the level of malondialdehyde (MDA), a marker of lipid peroxidation, was 43-58% lower in the TMT/CGK-treated group than the TMT/vehicle-treated group. DISCUSSION: These results demonstrate that CGK fermented by mixed culture of B. subtilis and L. sakei could exert a wide range of beneficial activities for neurodegenerative diseases, including Alzheimer, Parkinson, and Huntington disease.

Reversal of Trimethyltin-Induced Learning and Memory Deficits by 3,5-Dicaffeoylquinic Acid.

The antiamnesic effect of 3,5-dicaffeoylquinic acid (3,5-diCQA) as the main phenolic compound in Artemisia argyi H. extract on cognitive dysfunction induced by trimethyltin (TMT) (7.1 µg/kg of body weight; intraperitoneal injection) was investigated in order to assess its ameliorating function in mice. In several behavioral tests, namely, the Y-maze, passive avoidance, and Morris water maze (MWM) test, 3,5-diCQA significantly ameliorated learning and memory deficits. After the behavioral tests, brain tissues from the mice were analyzed to characterize the basis of the neuroprotective effect. Acetylcholine (ACh) levels increased, whereas the activity of acetylcholinesterase (AChE) decreased upon administration of 3,5-diCQA. In addition, 3,5-diCQA effectively protected against an increase in malondialdehyde (MDA) content, an increase in the oxidized glutathione (GSH) ratio, and a decline of total superoxide dismutase (SOD) level. 3,5-diCQA may prevent neuronal apoptosis through the protection of mitochondrial activities and the repression of apoptotic signaling molecules such as p-Akt, BAX, and p-tau (Ser 404).

Effect of Chaenomeles sinensis Extract on Choline Acetyltransferase Activity and Trimethyltin-Induced Learning and Memory Impairment in Mice.

The aim of this study was to search for a novel choline acetyltransferase (ChAT) activator from plants traditionally grown in Korea. An ethanol extract from Chaenomeles sinensis Koehne showed the highest ChAT-activating effect in vitro in an assay that used human neuroblastoma cells and [(14)C]acetyl-CoA. The active compound was speculated to be stearic acid methyl ester (SAME). In an in vivo experiment, C. sinensis extract and SAME improved trimethyltin (TMT)-induced deficits in learning and memory in mice as assessed by a Y-maze behavioral test and a passive avoidance test. The C. sinensis extract might attenuate the TMT-induced brain disorder. This study suggests that SAME from C. sinensis might be useful in the treatment of Alzheimer's disease.