Aspartame Intake Delayed Puberty Onset in Female Offspring Rats and Girls.

SCOPE: The disturbance of the hypothalamic-pituitary-gonadal (HPG) axis, gut microbiota (GM) community, and short-chain fatty acids (SCFAs) is a triggering factor for pubertal onset. The study investigates the effects of the long-term intake of aspartame on puberty and GM in animals and humans. METHODS AND RESULTS: Aspartame-fed female offspring rats result in vaginal opening time prolongation, serum estrogen reduction, and serum luteinizing hormone elevation. , 60 mg kg-1 aspartame treatment decreases the mRNA levels of gonadotropin-releasing hormone (GnRH), Kiss1, and G protein-coupled receptor 54 (GPR54), increases the mRNA level of RFamide-related peptide-3 (RFRP-3), and decreases the expression of GnRH neurons in the hypothalamus. Significant differences in relative bacterial abundance at the genus levels and decreased fecal SCFA levels are noted by 60 mg kg-1 aspartame treatment. Among which, Escherichia-Shigella is negatively correlated with several SCFAs. In girls, high-dose aspartame consumption decreases the risk of precocious puberty. CONCLUSIONS: Aspartame reduces the chance of puberty occurring earlier than usual in female offspring and girls. Particularly, 60 mg kg-1 aspartame-fed female offspring delays pubertal onset through the dysregulation of HPG axis and GM composition by inhibiting the Kiss1/GPR54 system and inducing the RFRP-3. An acceptable dose of aspartame should be recommended during childhood.

Consumption of Non-Nutritive Sweetener, Acesulfame Potassium Exacerbates Atherosclerosis through Dysregulation of Lipid Metabolism in ApoE-/- Mice.

Obesity is associated with the risk of cardiovascular disease, and non-nutritive sweetener, such as acesulfame potassium (AceK) has been used to combat obesity. However, the effects of AceK on cardiovascular disease are still unclear. In this study, high cholesterol diet (HCD)-fed ApoE-/- mice had dysregulated plasma lipid profile, and developed atherosclerosis, determined by atherosclerotic plaque in the aorta. Supplement of AceK in HCD worsened the dyslipidemia and increased atherosclerotic plaque, as compared with HCD-fed ApoE-/- mice. Since treatment of AceK in RAW264.7 macrophages showed no significant effects on inflammatory cytokine expressions, we then investigated the impacts of AceK on lipid metabolism. We found that AceK consumption enhanced hepatic lipogenesis and decreased ß-oxidation in ApoE-/- mice. In addition, AceK directly increased lipogenesis and decreased ß-oxidation in HepG2 cells. Taken together, a concurrent consumption of AceK exacerbated HCD-induced dyslipidemia and atherosclerotic lesion in ApoE-/- mice, and AceK might increase the risk of atherosclerosis under HCD.

Eicosapentaenoic Acid Inhibits KRAS Mutant Pancreatic Cancer Cell Growth by Suppressing Hepassocin Expression and STAT3 Phosphorylation.

BACKGROUND: The oncogenic Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation was reported to be the signature genetic event in most cases of pancreatic ductal adenocarcinoma (PDAC). Hepassocin (HPS/FGL1) is involved in regulating lipid metabolism and the progression of several cancer types; however, the underlying mechanism of HPS/FGL1 in the KRAS mutant PDAC cells undergoing eicosapentaenoic acid (EPA) treatment remains unclear. METHODS: We measured HPS/FGL1 protein expressions in a human pancreatic ductal epithelial (HPNE) normal pancreas cell line, a KRAS-wild-type PDAC cell line (BxPC-3), and KRAS-mutant PDAC cell lines (PANC-1, MIA PaCa-2, and SUIT-2) by Western blot methods. HEK293T cells were transiently transfected with corresponding KRAS-expressing plasmids to examine the level of HPS expression with KRAS activation. We knocked-down HPS/FGL1 using lentiviral vectors in SUIT-2 cells and measured the cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenicity assays. Furthermore, a lipidomic analysis was performed to profile changes in lipid metabolism after HPS/FGL1 knockdown. RESULTS: We found that the HPS/FGL1 level was significantly upregulated in KRAS-mutated PDAC cells and was involved in KRAS/phosphorylated (p)-signal transduction and activator of transcription 3 (STAT3) signaling, and the knockdown of HPS/FGL1 in SUIT-2 cells decreased cell proliferation through increasing G2/M cell cycle arrest and cyclin B1 expression. In addition, the knockdown of HPS/FGL1 in SUIT-2 cells significantly increased omega-3 polyunsaturated fatty acids (PUFAs) and EPA production but not docosahexaenoic acid (DHA). Moreover, EPA treatment in SUIT-2 cells reduced the expression of de novo lipogenic protein, acetyl coenzyme A carboxylase (ACC)-1, and decreased p-STAT3 and HPS/FGL1 expressions, resulting in the suppression of cell viability. CONCLUSIONS: Results of this study indicate that HPS is highly expressed by KRAS-mutated PDAC cells, and HPS/FGL1 plays a crucial role in altering lipid metabolism and increasing cell growth in pancreatic cancer. EPA supplements could potentially inhibit or reduce ACC-1-involved lipogenesis and HPS/FGL1-mediated cell survival in KRAS-mutated pancreatic cancer cells.

Chronic exposure to high fat diet triggers myelin disruption and interleukin-33 upregulation in hypothalamus.

BACKGROUND: Hypothalamic inflammation including astrogliosis and microglia activation occurs after intake of high fat diet (HFD) in rodent models or in obese individuals. However, the effect of chronic HFD feeding on oligodendrocytes (OLGs), a myelin-producing glial population in the central nervous system (CNS), remains unclear. In this study, we used 8-week old male C57BL/6 mice fed by HFD for 3-6 months to induce chronic obesity. RESULTS: The transmission electron microscopy imaging analysis showed that the integrity of hypothalamic myelin was disrupted after HFD feeding for 4 and 6 months. Moreover, the accumulation of Iba1+-microglia with an amoeboid hypertrophic form was continually observed in arcuate nucleus of HFD-fed mice during the entire feeding time period. Interleukin-33 (IL-33), a tissue alarmin upon injury to the CNS, was detected with an increased level in hypothalamus after HFD feeding for 3 and 4 months. Furthermore, the in vitro study indicated that exposure of mature OLGs to IL-33 impaired OLG cell structure along with a decline in the expression of myelin basic protein. CONCLUSIONS: Altogether, our findings demonstrate that chronic HFD feeding triggers hypothalamic myelin disruption in accompany with IL-33 upregulation and prolonged microglial activation in hypothalamus. Given that the addition of exogenous IL-33 was harmful for the maturation of OLGs, an increase in IL-33 by chronic HFD feeding might contribute to the induction of hypothalamic myelin disruption.

Evodiamine Exerts an Anti-Hepatocellular Carcinoma Activity through a WWOX-Dependent Pathway.

Evodiamine is one of the main components isolated from Evodia rutaecarpa, and it has been reported to exert inhibitory effects on cancers by anti-proliferative and apoptosis-inducing activities. Although the anti-cancer activity of evodiamine has been identified, the precise mechanisms of this action remain obscure. While previous studies indicated that evodiamine exerts anti-tumor effects through inhibiting ß-catenin activity, and WW domain-containing oxidoreductase (WWOX) regulates ß-catenin accumulation in cytoplasm, the effects of evodiamine on the expression of WWOX are still unknown. In this study, we provide evidence that evodiamine dose- and time-dependently inhibits both Mus musculus and Homo sapiens hepatocellular carcinoma (HCC) cells, as well as Hepa1-6 and HepG2 cell proliferation. We further tested the therapeutic effects of evodiamine in Hepa1-6 hepatoma-bearing mice, and we found that treatment of evodiamine by oral gavage significantly decreased the tumor size of the mice. Moreover, the expressions of WWOX were dose-dependently increased in HCC cell lines as well as in Hepa1-6 hepatoma-bearing mice after the treatment with evodiamine. Knockdown of WWOX in HepG2 and Hepa1-6 cells diminished the effects of evodiamine on the inhibitory effect of cancer cell growth, indicating that evodiamine induced anti-cancer activity through a WWOX-dependent pathway. As such, evodiamine activated WWOX to exert an anti-HCC activity, and might be a potential therapeutic or preventive candidate for HCC treatment.

In vivo and in vitro anti-tumor effects of fungal extracts.

Fungal extracts are extensively used as nutritional supplements in Far-Eastern Asia. In this study, we aimed to evaluate the anti-cancer activities of some different fungal species against different cancer cell lines. The water or ethanol extracts of Fomitopsis pinicola (F. pinicola), Ganoderma sinense, Fomitopsis officinalis, Polyporus melanopus, and Taiwanofungus camphorates were used to evaluate the anti-cancer activities in various cancer cells. We found that all of the fungi ethanol extracts used in this study exert anti-cancer activities in vitro, whereas water extracts show lower inhibitory activities as determined by 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Among the tested fungi species, F. pinicola ethanol extract exerts the most significant anti-cancer activity (growth inhibitory ratio 82.8%, p < 0.001) by increasing cell apoptosis. Moreover, F. pinicola ethanol extract significantly decreased tumor size (tumor growth inhibitory ratio 54%, p < 0.05) and increased the lifespan in mice bearing sarcoma-180 tumors. Taken together, this is the first study indicating the anti-tumor effect of F. pinicola in vivo and in vitro. F. pinicola ethanol extract induces cell apoptosis to exert a significant anti-tumor activity, with potential to be a new alternative anti-tumor medicine.

Decrease of plasma glucose by allantoin, an active principle of yam ( Dioscorea spp.), in streptozotocin-induced diabetic rats.

The effect of allantoin, an active component of yam, on plasma glucose of streptozotocin-induced diabetic rats (STZ-diabetic rats) is investigated. Allantoin decreased plasma glucose levels in a dose-related manner, which was reduced by pretreatment with naloxone or naloxonazine. A concomitant increase in plasma ß-endorphin, detected by enzyme-linked immunosorbent assay, was observed. Moreover, allantoin enhanced ß-endorphin release from the isolated adrenal medulla of STZ-diabetic rat in a dose-related manner. However, its plasma glucose lowering action was reduced but not totally abolished by bilateral adrenalectomy. Furthermore, allantoin directly increased radioactive glucose uptake in isolated skeletal muscle, and repeated administration for 3 days increased GLUT4 mRNA and protein levels in muscle. This effect was markedly reduced in STZ-diabetic rats with bilateral adrenalectomy. This study suggests that allantoin increases GLUT4 gene expression in muscle by increasing ß-endorphin secretion from the adrenal gland in STZ-diabetic rats.

Autonomic regulation of insulin secretion is changed by pentobarbital in mice.

It has been established that insulin secretion is regulated by autonomic nervous homeostasis. In the screen of plasma glucose level, anesthetized animals were widely used. However, effects of anesthetics on blood glucose remain unclear. In the present study, we compared the hypoglycemic action of ginseng that was induced by insulin secretion in mice between conscious and under anesthesia with pentobarbital. The hypoglycemic effect of ginseng was only produced in anesthetized BALB/c mice but not in the conscious mice. Similar results were also observed in C57BL/6 mice. However, the hypoglycemic action of ginseng failed to produce in anesthetized BALB/c mice received streptozotocin to induce type-1 like diabetes showing an insulin-dependent manner. The plasma insulin level in anesthetized BALB/c mice was markedly raised by ginseng but this effect was not observed in conscious mice. Blockade of muscarinic receptors by atropine inhibited ginseng-induced insulin secretion in anesthetized mice. Otherwise, the hypoglycemic action of ginseng was restored in conscious mice treated guanethidine at a sufficient dose to block sympathetic tone. In conclusion, the obtained results suggest that insulin secretion regulated by autonomic nervous homeostasis can be changed by pentobarbital through decrement in sympathetic tone to increase the insulin secretion induced by agent(s) via higher of parasympathetic tone. This finding is suitable to explain the critical hypoglycemia was not observed in subjects received ginseng.

Stimulatory effect of stevioside on peripheral mu opioid receptors in animals.

Stevioside is a dietary supplement widely used as a sweetener to prevent hyperglycemic disorders. However, the action mechanisms of this substance for glucose homeostasis remain obscure. In the present study, a dose-related plasma glucose reduction was observed in Wistar rats receiving intraperitoneally injections of stevioside. Similar to the regulation of glucose metabolism by the activation of mu opioid receptors, this action of stevioside was reversed by naloxonazine under the blockade of mu opioid receptors. We also found that stevioside increased glycogen synthesis in isolated hepatocytes, which was concentration-dependently blocked by naloxonazine. Stevioside did not modify the plasma beta-endorphin levels in Wistar rats but it directly increased the phosphorylation of mu opioid receptors in Chinese hamster ovary cells transfected with mu opioid receptors. Unlike morphine, chronic administration of stevioside did not induce the withdrawal signs in mice. Furthermore, stevioside by intraperitoneal injections did not influence the feeding behaviors of rats. By contrast, intracerebroventricular injections of stevioside increased the rats' food intake, which was also inhibited by pretreatment with naloxonazine. These results showed that it is difficult for stevioside to enter the brain. Stevioside has the ability to activate peripheral mu opioid receptors for lowering plasma glucose and to increase glycogen synthesis in liver. Thus, the stimulation of peripheral mu opioid receptors is responsible for the action of stevioside in the regulation of glucose homeostasis.