Longitudinal Comparative Analysis of Circulating Tumor DNA and Matched Tumor Tissue DNA in Patients with Metastatic Colorectal Cancer Receiving Palliative First-Line Systemic Anti-Cancer Therapy.

Purpose: This study aimed to compare tumor tissue DNA (ttDNA) and circulating tumor DNA (ctDNA) to explore the clinical applicability of ctDNA and to better understand clonal evolution in patients with metastatic colorectal cancer undergoing palliative first-line systemic therapy. Materials and Methods: We performed targeted sequencing analysis of 88 cancer-associated genes using germline DNA, ctDNA at baseline (baseline-ctDNA), and ctDNA at progressive disease (PD-ctDNA). The results were compared with ttDNA data. Results: Among 208 consecutively enrolled patients, we selected 84 (41 males; median age 59, range 35 to 90) with all four sample types available. A total of 202 driver mutations were found in 34 genes. ttDNA exhibited the highest mutation frequency (n=232), followed by baseline-ctDNA (n=155) and PD-ctDNA (n=117). Sequencing ctDNA alongside ttDNA revealed additional mutations in 40 patients (47.6%). PD-ctDNA detected 13 novel mutations in 10 patients (11.9%) compared to ttDNA and baseline-ctDNA. Notably, 7 mutations in 5 patients (6.0%) were missense or nonsense mutations in APC, TP53, SMAD4, and CDH1 genes. In baseline-ctDNA, higher maximal variant allele frequency (VAF) values (p=0.010) and higher VAF values of APC (p=0.012), TP53 (p=0.012), and KRAS (p=0.005) mutations were significantly associated with worse overall survival. Conclusion: While ttDNA remains more sensitive than ctDNA, our ctDNA platform demonstrated validity and potential value when ttDNA was unavailable. Post-treatment analysis of PD-ctDNA unveiled new pathogenic mutations, signifying cancer's clonal evolution. Additionally, baseline-ctDNA's VAF values were prognostic after treatment.

Gallbladder adenocarcinomas undergo subclonal diversification and selection from precancerous lesions to metastatic tumors.

We aimed to elucidate the evolutionary trajectories of gallbladder adenocarcinoma (GBAC) using multi-regional and longitudinal tumor samples. Using whole-exome sequencing data, we constructed phylogenetic trees in each patient and analyzed mutational signatures. A total of 11 patients including 2 rapid autopsy cases were enrolled. The most frequently altered gene in primary tumors was ERBB2 and TP53 (54.5%), followed by FBXW7 (27.3%). Most mutations in frequently altered genes in primary tumors were detectable in concurrent precancerous lesions (biliary intraepithelial neoplasia [BilIN]), but a substantial proportion was subclonal. Subclonal diversity was common in BilIN (n=4). However, among subclones in BilIN, a certain subclone commonly shrank in concurrent primary tumors. In addition, selected subclones underwent linear and branching evolution, maintaining subclonal diversity. Combined analysis with metastatic tumors (n=11) identified branching evolution in nine patients (81.8%). Of these, eight patients (88.9%) had a total of 11 subclones expanded at least sevenfold during metastasis. These subclones harbored putative metastasis-driving mutations in cancer-related genes such as SMAD4, ROBO1, and DICER1. In mutational signature analysis, six mutational signatures were identified: 1, 3, 7, 13, 22, and 24 (cosine similarity >0.9). Signatures 1 (age) and 13 (APOBEC) decreased during metastasis while signatures 22 (aristolochic acid) and 24 (aflatoxin) were relatively highlighted. Subclonal diversity arose early in precancerous lesions and clonal selection was a common event during malignant transformation in GBAC. However, selected cancer clones continued to evolve and thus maintained subclonal diversity in metastatic tumors.

Cetuximab resistance induced by hepatocyte growth factor is overcome by MET inhibition in KRAS, NRAS, and BRAF wild-type colorectal cancers.

PURPOSE: Recent evidence has highlighted the role of hepatocyte growth factor (HGF) as a putative biomarker to predict EGFR inhibitor resistance. This study investigated the impact of plasma HGF levels on EGFR inhibition and the counter effect of MET inhibition in KRAS, NRAS, and BRAF (RAS/RAF) wild-type colorectal cancers (CRCs). METHODS: Plasma HGF levels were analyzed with clinical outcomes of patients with metastatic CRC (mCRC) receiving palliative first-line chemotherapy. Then, in vitro experiments were conducted to validate the clinical findings and to establish pre-clinical evidence of MET inhibition by capmatinib. RESULTS: A total of 80 patients were included: cetuximab + FOLFIRI (n = 35) and bevacizumab + FOLFIRI (n = 45). Both progression-free survival (PFS) and overall survival (OS) were significantly lesser in the high vs low HGF group: median 11.8 vs. 24.7 months, respectively, for PFS (p = 0.009), and median 21.1 months vs. not reached, respectively, for OS (p = 0.018). The difference was significantly evident in the cetuximab group. In five RAS/RAF wild-type CRC cells, the addition of HGF activated ERK1/2 and AKT via MET phosphorylation, resulting in cetuximab resistance in vitro. In cetuximab-sensitive Caco-2 and SNU-C4 cells, capmatinib overcame cetuximab resistance in the presence of HGF by attenuating HGF-induced MET signaling activation. CONCLUSION: Patients with mCRC receiving cetuximab + FOLFIRI who presented with high plasma HGF levels had significantly worse PFS and OS. Cetuximab resistance induced by HGF was mediated by AKT and ERK activation and overcome by MET inhibition in vitro.

Amphiregulin can predict treatment resistance to palliative first-line cetuximab plus FOLFIRI chemotherapy in patients with RAS wild-type metastatic colorectal cancer.

Amphiregulin (AREG) is an epidermal growth factor receptor (EGFR) ligand. The aim of this study was to investigate the effects of baseline plasma AREG levels in KRAS, NRAS, and BRAF wild-type metastatic colorectal cancer (CRC) on treatment outcome with palliative first-line cetuximab + FOLFIRI chemotherapy. Chemotherapy outcomes were analyzed based on baseline plasma AREG levels. The clinical findings were further validated using an in vitro model of CRC. Among 35 patients, the progression-free survival (PFS) was significantly inferior in patients with high AREG than in those with low AREG levels: 10.9 vs. 24.2 months, respectively (p = 0.008). However, after failure of first-line chemotherapy, AREG levels were associated with neither PFS (4.8 vs. 11.6 months; p = 0.215) nor overall survival (8.4 vs. 13.3 months; p = 0.975). In SNU-C4 and Caco-2 cells which were relatively sensitive to cetuximab among the seven CRC cell lines tested, AREG significantly decreased the anti-proliferative effect of cetuximab (p < 0.05) via AKT and ERK activation. However, after acquiring cetuximab resistance with gradual exposure for more than 6 months, AREG neither increased colony formation nor activated AKT and ERK after cetuximab treatment. Our results suggest that plasma AREG is a potential biomarker to predict clinical outcomes after cetuximab-based chemotherapy.

Correlation between tumor infiltrating immune cells and peripheral regulatory T cell determined using methylation analyses and its prognostic significance in resected gastric cancer.

Peripheral regulatory T cells (pTregs) are a highly immunosuppressive fraction of CD4+ T cells. We aimed to evaluate the clinical significance of pTregs in patients with gastric cancer and to determine the correlation between pTregs and immune cell infiltration in tumor microenvironment. pTregs status was determined by assessing the pTreg/total T-cell ratio (ratio of Foxp3 Treg-specific demethylated region (TSDR) to CD3G/CD3D demethylation, so-called Cellular Ratio of Immune Tolerance "ImmunoCRIT") using methylation analyses in 433 patients with gastric cancer who received curative surgery. Among 422 evaluable patients, 230 (54.5%) had high ImmunoCRIT (> 21.0). Patients with high ImmunoCRIT had significantly shorter disease-free survival (DFS) and overall survival (OS) than those with high ImmunoCRIT (p = 0.030, p = 0.008, respectively). In multivariate analysis, high ImmunoCRIT kept a prognostic role for shorter OS (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.4-2.9; p = 0.005). CD3+ cell density and CD4+ cell density was significantly higher within the tumor in high ImmunoCRIT group than those in low ImmunoCRIT group (CD3+ cell, 202.12/mm2 vs. 172.2/mm2, p = 0.029; CD4+ cell, 56.5/mm2 vs. 43.5/mm2, p = 0.007). In conclusion, the peripheral ImmunoCRIT determined by epigenetic methylation analysis provides prognostic information in resected gastric tumors.

PI3K p110α Blockade Enhances Anti-Tumor Efficacy of Abemaciclib in Human Colorectal Cancer Cells.

Targeting cell cycle regulation in colorectal cancer has not been fully evaluated. We investigated the efficacy of the CDK4/6 inhibitor, abemaciclib, and confirmed a synergistic interaction for PI3K p110α and CDK dual inhibition in colorectal cancer cell lines. Caco-2 and SNU-C4 cell lines were selected to explore the mechanism of action for and resistance to abemaciclib. In vitro and in vivo models were used to validate the anti-tumor activity of abemaciclib monotherapy and BYL719 combination therapy. Abemaciclib monotherapy inhibited cell cycle progression and proliferation in Caco-2 and SNU-C4 cells. CDK2-mediated Rb phosphorylation and AKT phosphorylation appeared to be potential resistance mechanisms to abemaciclib monotherapy. Abemaciclib/BYL719 combination therapy demonstrated synergistic effects regardless of PIK3CA mutation status but showed greater efficacy in the PIK3CA mutated SNU-C4 cell line. Growth inhibition, cell cycle arrest, and migration inhibition were confirmed as mechanisms of action for this combination. In an SNU-C4 mouse xenograft model, abemaciclib/BYL719 combination resulted in tumor growth inhibition and apoptosis with tolerable toxicity. Dual blockade of PI3K p110α and CDK4/6 showed synergistic anti-tumor effects in vivo and in vitro in human colorectal cancer cell lines. This combination could be a promising candidate for the treatment of patients with advanced colorectal cancer.

PI3K-targeting strategy using alpelisib to enhance the antitumor effect of paclitaxel in human gastric cancer.

PIK3CA mutations are frequently observed in various human cancers including gastric cancer (GC). This study was conducted to investigate the anti-tumor effects of alpelisib, a PI3K p110α-specific inhibitor, using preclinical models of GC. In addition, the combined effects of alpelisib and paclitaxel on GC were evaluated. Among the SNU1, SNU16, SNU484, SNU601, SNU638, SNU668, AGS, and MKN1 GC cells, three PIK3CA-mutant cells were predominantly sensitive to alpelisib. Alpelisib monotherapy decreased AKT and S6K1 phosphorylation and induced G0/G1 phase arrest regardless of PIK3CA mutational status. The alpelisib and paclitaxel combination demonstrated synergistic anti-proliferative effects, preferentially on PIK3CA-mutant cells, resulting in increased DNA damage response and apoptosis. In addition, alpelisib and paclitaxel combination potentiated anti-migratory activity in PIK3CA-mutant cells. Alpelisib partially reversed epithelial-mesenchymal transition markers in PIK3CA-mutant cells. In a xenograft model of MKN1 cells, the alpelisib and paclitaxel combination significantly enhanced anti-tumor activity by decreasing Ki-67 expression and increasing apoptosis. Moreover, this combination tended to prolong the survival of tumor-bearing mice. Our data suggest promising anti-tumor efficacy of alpelisib alone or in combination with paclitaxel in PIK3CA-mutant GC cells.

Gomisin N from Schisandra chinensis Ameliorates Lipid Accumulation and Induces a Brown Fat-Like Phenotype through AMP-Activated Protein Kinase in 3T3-L1 Adipocytes.

Obesity results from an imbalance between energy intake and energy expenditure, in which excess fat is stored as triglycerides (TGs) in white adipocytes. Recent studies have explored the anti-obesity effects of certain edible phytochemicals, which suppress TG accumulation and stimulate a brown adipocyte-like phenotype in white adipocytes. Gomisin N (GN) is an important bioactive component of Schisandra chinensis, a woody plant endemic to Asia. GN has antioxidant, anti-inflammatory and hepatoprotective effects in vivo and in vitro. However, the anti-obesity effects of GN in lipid metabolism and adipocyte browning have not yet been investigated. In the present study, we aimed to determine whether GN suppresses lipid accumulation and regulates energy metabolism, potentially via AMP-activated protein kinase (AMPK), in 3T3-L1 adipocytes. Our findings demonstrate that GN inhibited adipogenesis and lipogenesis in adipocyte differentiation. Also, GN not only increased the expression of thermogenic factors, including uncoupling protein 1 (UCP1), but also enhanced fatty acid oxidation (FAO) in 3T3-L1 cells. Therefore, GN may have a therapeutic benefit as a promising natural agent to combat obesity.

Korean Red Ginseng and Korean black ginseng extracts, JP5 and BG1, prevent hepatic oxidative stress and inflammation induced by environmental heat stress.

BACKGROUND: Continuous exposure to high temperatures can lead to heat stress. This stress response alters the expression of multiple genes and can contribute to the onset of various diseases. In particular, heat stress induces oxidative stress by increasing the production of reactive oxygen species. The liver is an essential organ that plays a variety of roles, such as detoxification and protein synthesis. Therefore, it is important to protect the liver from oxidative stress caused by heat stress. Korean ginseng has a variety of beneficial biological properties, and our previous studies showed that it provides an effective defense against heat stress. METHODS: We investigated the ability of Korean Red Ginseng and Korean black ginseng extracts (JP5 and BG1) to protect against heat stress using a rat model. We then confirmed the active ingredients and mechanism of action using a cell-based model. RESULTS: Heat stress significantly increased gene and protein expression of oxidative stress-related factors such as catalase and SOD2, but treatment with JP5 (Korean Red Ginseng extract) and BG1 (Korean black ginseng extract) abolished this response in both liver tissue and HepG2 cells. In addition, JP5 and BG1 inhibited the expression of inflammatory proteins such as p-NF-κB and tumor necrosis factor alpha-α. In particular, JP5 and BG1 decreased the expression of components of the NLRP3 inflammasome, a key inflammatory signaling factor. Thus, JP5 and BG1 inhibited both oxidative stress and inflammation. CONCLUSIONS: JP5 and BG1 protect against oxidative stress and inflammation induced by heat stress and help maintain liver function by preventing liver damage.

Spirulina maxima extract prevents activation of the NLRP3 inflammasome by inhibiting ERK signaling.

The blue-green alga Spirulina maxima is a microscopic filamentous cyanobacterium. Spirulina was recently reported to elicit beneficial effects such as reducing cholesterol and inducing weight loss; however, its effects on inflammation are unknown. To determine the effect of S. maxima extract (SME) on innate immunity, we investigated the NLRP3 inflammasome activation, which is a multiprotein scaffolding complex that plays important roles in innate immune responses to many pathogenic infections in macrophages. SME suppressed lipopolysaccharide (LPS)-induced upregulation of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-12, IL-1ß, and IL-18 in RAW264.7 cells. In addition, SME attenuated LPS-induced NLRP3 inflammasome activation, and thus pro-IL-1ß could not be cleaved to IL-1ß by activated caspase-1, which is activated by the NLRP3 inflammasome in RAW264.7 cells. Moreover, SME inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK) in RAW264.7 cells, and attenuated the generation of ERK1 induced-reactive oxygen species (ROS), resulting in decreased expression of NF-κB. These findings suggest that SME suppresses the effects of the NLRP3 inflammasome via regulation of extracellular signal-regulated kinase (ERK). In summary, we demonstrated that SME prevents activation of the NLRP3 inflammasome by inhibiting ERK signaling.

Afatinib Overcomes Pemetrexed-Acquired Resistance in Non-Small Cell Lung Cancer Cells Harboring an EML4-ALK Rearrangement.

BACKGROUND: The aim of this study is to elucidate the mechanisms of acquired resistance to pemetrexed in echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer. METHODS: We analyzed the sensitivity to pemetrexed and the expression patterns of various proteins after pemetrexed treatment in the cell lines, A549, NCI-H460, NCI-H2228 harboring EML4-ALK variant 3, and NCI-H3122 harboring EML4-ALK variant 1. Pemetrexed-resistant cell lines were also generated through long-term exposure to pemetrexed. RESULTS: The EML4-ALK variant 1 rearranged NCI-H3122 was found to be more sensitive than the other cell lines. Cell cycle analysis after pemetrexed treatment showed that the fraction of cells in the S phase increased in A549, NCI-H460, and NCI-H2228, whereas the fraction in the apoptotic sub-G1 phase increased in NCI-H3122. The pemetrexed-resistant NCI-H3122 cell line showed increased expression of EGFR and HER2 compared to the parent cell line, whereas A549 and NCI-H460 did not show this change. The pan-HER inhibitor afatinib inhibited this alternative signaling pathway, resulting in a superior cytotoxic effect in pemetrexed-resistant NCI-H3122 cell lines compared to that in the parental cells line. CONCLUSION: The activation of EGFR-HER2 contributes to the acquisition of resistance to pemetrexed in EML4-ALK rearranged non-small cell lung cancer. However, the inhibition of this alternative survival signaling pathway with RNAi against EGFR-HER2 and with afatinib overcomes this resistance.

Korean ginseng extract ameliorates abnormal immune response through the regulation of inflammatory constituents in Sprague Dawley rat subjected to environmental heat stress.

BACKGROUND: Increases in the average global temperature cause heat stress-induced disorders by disrupting homeostasis. Excessive heat stress triggers an imbalance in the immune system; thus protection against heat stress is important to maintain immune homeostasis. Korean ginseng (Panax ginseng Meyer) has been used as a herbal medicine and displays beneficial biological properties. METHODS: We investigated the protective effects of Korean ginseng extracts (KGEs) against heat stress in a rat model. Following acclimatization for 1 week, rats were housed at room temperature for 2 weeks and then exposed to heat stress (40°C/2 h/day) for 4 weeks. Rats were treated with three KGEs from the beginning of the second week to the end of the experiment. RESULTS: Heat stress dramatically increased secretion of inflammatory factors, and this was significantly reduced in the KGE-treated groups. Levels of inflammatory factors such as heat shock protein 70, interleukin 6, inducible nitric oxide synthase, and tumor necrosis factor-alpha were increased in the spleen and muscle upon heat stress. KGEs inhibited these increases by down-regulating heat shock protein 70 and the associated nuclear factor-κB and mitogen-activated protein kinase signaling pathways. Consequently, KGEs suppressed activation of T-cells and B-cells. CONCLUSION: KGEs suppress the immune response upon heat stress and decrease the production of inflammatory cytokines in muscle and spleen. We suggest that KGEs protect against heat stress by inhibiting inflammation and maintaining immune homeostasis.

BGJ398, A Pan-FGFR Inhibitor, Overcomes Paclitaxel Resistance in Urothelial Carcinoma with FGFR1 Overexpression.

Paclitaxel (PTX) is commonly used to treat urothelial carcinoma (UC) after platinum-based chemotherapy has failed. However, single-agent taxane therapy is not sufficient to inhibit tumor progression and drug resistance in advanced UC. Epithelial-to-mesenchymal transition (EMT) induced by fibroblast growth factor receptor (FGFR)1 signaling has been proposed as a mechanism of PTX resistance, but it is unclear whether this can be overcome by FGFR1 inhibition. The present study investigated whether FGFR1 overexpression contributes to PTX resistance and whether FGFR inhibition can enhance PTX efficacy in UC. The effects of PTX combined with the FGFR inhibitor BGJ398 were evaluated in UC cell lines by flow cytometry; Western blot analysis; cell viability, migration, and colony forming assays; and RNA interference. PTX+BGJ398 induced cell cycle arrest and apoptosis in UC cells with mesenchymal characteristics was accompanied by downregulation of cyclin D1 protein and upregulation of gamma-histone 2A family member X and cleaved poly(ADP-ribose) polymerase. Additionally, PTX+BGJ398 synergistically suppressed UC cell migration and colony formation via regulation of EMT-associated factors, while FGFR1 knockdown enhanced the antitumor effect of PTX. These findings provide a basis for development of effective strategies for overcoming PTX resistance in UC through inhibition of FGFR1 signaling.

Spirulina maxima Extract Reduces Obesity through Suppression of Adipogenesis and Activation of Browning in 3T3-L1 Cells and High-Fat Diet-Induced Obese Mice.

Obesity predisposes animals towards the metabolic syndrome and diseases such as type 2 diabetes, atherosclerosis, and cardiovascular disease. Spirulina maxima is a microalga with anti-oxidant, anti-cancer, and neuroprotective activities, but the anti-obesity effect of Spirulina maxima 70% ethanol extract (SM70EE) has not yet been fully established. We investigated the effect of SM70EE on adipogenesis, lipogenesis, and browning using in vitro and in vivo obesity models. SM70EE treatment reduced lipid droplet accumulation by the oil red O staining method and downregulated the adipogenic proteins C/EBPα, PPARγ, and aP2, and the lipogenic proteins SREBP1, ACC, FAS, LPAATß, Lipin1, and DGAT1 by western blot analysis. In addition, the index components of SM70EE, chlorophyll a, and C-phycocyanin, reduced adipogenesis and lipogenesis protein levels in 3T3-L1 and C3H10T1/2 cells. High-fat diet (HFD)-fed mice administered with SM70EE demonstrated smaller adipose depots and lower blood lipid concentrations than control HFD-fed mice. The lower body mass gain in treated SM70EE-administrated mice was associated with lower protein expression of adipogenesis factors and higher expression of AMPKα-induced adipose browning proteins PRDM16, PGC1α, and UCP1. SM70EE administration ameliorates obesity, likely by reducing adipogenesis and activating the thermogenic program, in 3T3-L1 cells and HFD-induced obese mice.

Ginsenoside Rg5 prevents apoptosis by modulating heme-oxygenase-1/nuclear factor E2-related factor 2 signaling and alters the expression of cognitive impairment-associated genes in thermal stress-exposed HT22 cells.

Our results suggested that thermal stress can lead to activation of hippocampal cell damage and reduction of memory-associated molecules in HT22 cells. These findings also provide a part of molecular rationale for the role of ginsenoside Rg5 as a potent cognitive impairment preventive compound in blocking the initiation of hippocampal damage.

Spirulina maxima extract prevents cell death through BDNF activation against amyloid beta 1-42 (Aß1-42) induced neurotoxicity in PC12 cells.

Spirulina maxima is a blue-green micro alga that contains abundant amounts of proteins (60-70%), vitamins, chlorophyll a, and C-phycocyanin (C-PC). It has been shown to reduce oxidative stress, and prevent diabetes and non-alcoholic fatty liver disease. However, it is unclear whether Spirulina maxima 70% ethanol extract (SM70EE), chlorophyll a, and C-PC prevent Aß1-42-induced neurotoxicity in PC12 cells. The aim of this study was to investigate whether SM70EE, chlorophyll a, and C-PC prevent Aß1-42-induced cell death. SM70EE, chlorophyll a, and C-PC suppressed the Aß1-42-induced increase in poly-ADP ribose polymerase-1 (PARP-1) cleavage and reduced Aß1-42-induced decreases in glutathione and its associated factors. The level of brain-derived neurotrophic factor (BDNF), which plays a critical role in neuronal survival and neuroprotection, was increased by SM70EE, chlorophyll a, and C-PC in Aß1-42-treated cells. SM70EE treatment decreased oxidative stress and cell death in response to Aß1-42 treatment, while simultaneously suppressing PARP cleavage and increasing the levels of glutathione (GSH) and its associated factors. Moreover, SM70EE lowered the levels of APP and BACE1, two major factors involved in APP processing, and increased BDNF expression during Aß1-42-induced neurotoxicity in PC12 cells. We suggest that SM70EE prevents cell death caused by Aß1-42 -induced neurotoxicity via the activation of BDNF signaling.

Gelidium elegans Extract Ameliorates Type 2 Diabetes via Regulation of MAPK and PI3K/Akt Signaling.

Gelidium elegans, a red alga native to the Asia Pacific region, contains biologically active polyphenols. We conducted a molecular biological study of the anti-diabetic effect of Gelidium elegans extract (GEE) in C57BL/KsJ-db/db mice. Mice that had been administered GEE had significantly lower body mass, water consumption, and fasting blood glucose than db/db controls. Moreover, hemoglobin A1c (HbA1c), an indicator of the glycemic status of people with diabetes, was significantly lower in mice that had been administered GEE. We also found that 200 mg/kg/day GEE upregulates the insulin signaling pathway by activating insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K), and increasing the expression of glucose transporter type 4 (GLUT4). In parallel, mitogen-activated protein kinase (MAPK) activity was lower in GEE-treated groups. In summary, these findings indicate that GEE regulates glucose metabolism by activating the insulin signaling pathway and downregulating the MAPK signaling pathway.

Single, 14-Day, and 13-Week Repeated Dose Toxicity Studies of Daily Oral Gelidium elegans Extract Administration to Rats.

Gelidium elegans extract (GEE) is derived from a red alga from the Asia-Pacific region, which has antioxidant, anti-adipogenic, and anti-hyperglycemic effects. However, detailed studies of the toxicology of GEE have not been performed. We evaluated the single oral dose toxicity of GEE in male and female Sprague-Dawley (CD) rats. GEE did not cause deaths or have toxic effects at dosages of 5000 mg/kg/day, although compound-colored stools and diarrhea were observed in both sexes, which lasted <2 days. Therefore, the LD50 of GEE is likely to be >5000 mg/kg. We next evaluated the repeated oral dose toxicity of GEE in CD rats over 14 days and 13 weeks. GEE did not induce any significant toxicological changes in either sex at 2000 mg/kg/day. Repeated oral dose toxicity studies showed no adverse effects, in terms of clinical signs, mortality, body mass, food consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy, organ masses, or histopathology, at dosages of 500, 1000, or 2000 mg/kg/day. The no observed adverse effect level (NOAEL) for GEE is thus likely to be >2000 mg/kg/day, and no pathology was identified in potential target organs. Therefore, this study indicates that repeated oral dosing with GEE is safe in CD rats.

Spirulina maxima Extract Ameliorates Learning and Memory Impairments via Inhibiting GSK-3ß Phosphorylation Induced by Intracerebroventricular Injection of Amyloid-ß 1-42 in Mice.

Spirulina maxima, a microalga containing high levels of protein and many polyphenols, including chlorophyll a and C-phycocyanin, has antioxidant and anti-inflammatory therapeutic effects. However, the mechanisms where by Spirulina maxima ameliorates cognitive disorders induced by amyloid-ß 1-42 (Aß1-42) are not fully understood. In this study, we investigated whether a 70% ethanol extract of Spirulina maxima (SM70EE) ameliorated cognitive impairments induced by an intracerebroventricular injection of Aß1-42 in mice. SM70EE increased the step-through latency time in the passive avoidance test and decreased the escape latency time in the Morris water maze test in Aß1-42-injected mice. SM70EE reduced hippocampal Aß1-42 levels and inhibited amyloid precursor protein processing-associated factors in Aß1-42-injected mice. Additionally, acetylcholinesterase activity was suppressed by SM70EE in Aß1-42-injected mice. Hippocampal glutathione levels were examined to determine the effects of SM70EE on oxidative stress in Aß1-42-injected mice. SM70EE increased the levels of glutathione and its associated factors that were reduced in Aß1-42-injected mice. SM70EE also promoted activation of the brain-derived neurotrophic factor/phosphatidylinositol-3 kinase/serine/threonine protein kinase signaling pathway and inhibited glycogen synthase kinase-3ß phosphorylation. These findings suggested that SM70EE ameliorated Aß1-42-induced cognitive impairments by inhibiting the increased phosphorylation of glycogen synthase kinase-3ß caused by intracerebroventricular injection of Aß1-42 in mice.

Anti-adipogenesis mechanism of pterostilbene through the activation of heme oxygenase-1 in 3T3-L1 cells.

BACKGROUND: Pterostilbene is a stilbenoid and major compound and has diverse biological activities, such as antioxidant, anti-cancer, and anti-inflammatory. However, it has not been shown whether pterostilbene affects the mitotic clonal expansion during adipogenesis in 3T3-L1 cells. PURPOSE: In the present study, we aimed to demonstrate the detailed mechanism of pterostilbene on anti-adipogenesis in 3T3-L1 cells. METHODS: Preadipocytes were converted to adipocytes through treatment with MDI (IBMX; 3-isobutyl-1-methylxanthine, DEX; dexamethasone, insulin) in 3T3-L1 cells. Oil Red O staining was performed to measure intracellular lipid accumulation. Western blot analysis was conducted to analyze protein expressions. RESULTS: Our results showed that pterostilbene decreased the lipid accumulation compared to MDI-induced differentiation, using Oil Red O staining. Next, we found that pterostilbene suppressed the expression of C/EBPα, PPARγ, and aP2 as well as the mitotic clonal expansion-associated proteins CHOP10 and C/EBPß, by western blot analysis. Our results indicated that pterostilbene may repress adipocyte differentiation through the activation of HO-1 expression prior to entering into the mitotic clonal expansion in 3T3-L1 cells. RNA interference was used to determine whether HO-1 acts as a regulator of CHOP10. CONCLUSION: Our results revealed that pterostilbene induced HO-1 expression which acts as a regulator of CHOP10. Together, we demonstrated that pterostilbene suppresses the initiation of mitotic clonal expansion via up-regulation of HO-1 expression during adipocyte differentiation of 3T3-L1 cells.