Structural Analysis and Novel Mechanism of Enteromorpha prolifera Sulfated Polysaccharide in Preventing Type 2 Diabetes Mellitus.

A water-soluble polysaccharide (EP) was purified from edible algae Enteromorpha prolifera. Gel permeation chromatography (GPC), ion chromatography (IC), and fourier transform infrared (FT-IR) were performed to characterize its structure. EP was defined as a low molecular weight (6625 Da) composed of rhamnose, glucose, glucuronic acid, xylose, galactose, arabinose, and mannose. Moreover, it was a sulfated polysaccharide with a degree of substitution (DS) of 1.48. Then, the high-fat diet/streptozotocin (HFD/STZ) induced diabetic mouse model was established to support evidence for a novel hypoglycemic mechanism. Results showed that blood glucose (47.32%), liver index (7.65%), epididymal fat index (16.86%), serum total cholesterol (26.78%) and triglyceride (37.61%) in the high-dose EP (HEP) group were significantly lower than those in the HFD group. Noticeably, the content of liver glycogen in the HEP group was significantly higher (62.62%) than that in the HFD group, indicating the promotion of glycogen synthesis. These beneficial effects were attributed to significantly increased protein kinase B (AKT) phosphorylation and its downstream signaling response. Further studies showed that diabetic mice exhibited excessive O-GlcNAcylation level and high expression of O-linked ß-D-N-acetylglucosamine transferase (OGT), which were decreased by 62.21 and 30.43% in the HEP group. This result suggested that EP had a similar effect to OGT inhibitors, which restored AKT phosphorylation and prevented pathoglycemia. This work reveals a novel hypoglycemic mechanism of EP, providing a theoretical basis for further studies on its pharmacological properties in improvement of T2DM.

High dietary copper intake induces perturbations in the gut microbiota and affects host ovarian follicle development.

Increasing evidence has shown that gut microbes play an important role in the reproductive endocrine system and the development of polycystic ovary syndrome (PCOS). However, whether environmental factors are involved in these gut microbiota alterations has seldom been studied. In this study, we aimed to explore the crucial role of an imbalanced gut microbiota on abnormal ovarian follicle development induced by Cu. A 1:1 matched case-control study with 181 PCOS patients and 181 controls was conducted using a propensity score matching protocol. Information regarding dietary Cu intake was obtained from a face-to-face dietary intake interview. Alterations in the gut microbiota were detected by high-throughput 16 S rDNA sequencing. The results showed that dietary Cu intake was positively correlated with the risk of PCOS, and the risk threshold was approximately 1.992 mg/d. Compared with those with dietary Cu intakes lower than 1.992 mg/d, those who had a higher dietary Cu intake had a 1.813-fold increased risk of PCOS (OR=1.813, 95% CI: 1.150-2.857). PCOS patients had a lower relative abundance of Bacteroides than controls (P = 0.003), and Bacteroides played a partial mediating role between dietary Cu exposure and PCOS (Pindirect effect=0.026, 95% CI: 0.002-0.072). In addition, an animal model of Cu exposure through the diet showed that Cu can induce gut microbiota disorder; increase serum levels of LPS, MDA, and IL-6; and alter host ovarian steroidogenesis to affect ovarian follicle development. Staphylococcus played a partial mediating role between Cu exposure and CYP17A1 (Pg_Staphylococcus=0.083, 95% CI: 0.001-0.228). Overall, this study shows that long-term exposure to high dietary Cu levels can affect the composition of the gut microbiota, cause inflammation and oxidative stress, and then interfere with hormone signaling, ultimately affecting ovarian follicle development.

Sulfated Polysaccharides from Enteromorpha prolifera Attenuate Lipid Metabolism Disorders in Mice with Obesity Induced by a High-Fat Diet via a Pathway Dependent on AMP-Activated Protein Kinase.

BACKGROUND: Obesity-related metabolic diseases have recently evoked worldwide attention. Studies have demonstrated that Enteromorpha polysaccharide (EP) exerts lipid-lowering effects, but the underlying mechanism remains unclear. OBJECTIVES: We investigated whether EP regulates lipid metabolism disorders in mice with high-fat diet (HFD)-induced obesity via an AMP-activated protein kinase (AMPK)-dependent pathway. METHODS: Six-week-old male C57BL/6J mice (18 ± 2 g) were fed a normal diet (ND; 10% energy from fats) or an HFD (60% energy from fats) for 6 weeks to induce obesity and treated intragastrically with EP (200 mg/kg body weight) or distilled water (10 mL/kg body weight) for 8 weeks. Biochemical indicators, AMPK-dependent pathways, and lipid metabolism-related genes were evaluated to assess the effects of EP on HFD-induced lipid metabolism disorders. The essential role of AMPK in the EP-mediated regulation of lipid metabolism was confirmed using HFD-fed male Ampka2-knockout mice (aged 6 weeks; 17 ± 2 g) treated or not treated with the above-mentioned dose of EP. The data were analyzed by t-tests, 2-factor and 1-way ANOVAs. RESULTS: Compared to the ND, the HFD resulted in a greater body weight (24.3%), perirenal fat index (2.2-fold), and serum total cholesterol (24.66%) and LDL cholesterol (1.25-fold) concentrations (P < 0.05) and dysregulated the AMPK-dependent pathway and the expression of most lipid metabolism-related genes (P < 0.05). Compared to the HFD, EP treatment resulted in a lower perirenal fat index (31.22%) and LDL cholesterol concentration (23.98%) and partly reversed the dysregulation of the AMPK-dependent pathway and the altered expression of lipid metabolism-related genes (P < 0.05). Ampka2 knockout abolished the above-mentioned effects of EP in obese mice and the EP-mediated effects on the expression of lipid metabolism-related genes (P > 0.05). CONCLUSIONS: These findings suggest that EP can ameliorate lipid metabolism disorders in mice with HFD-induced obesity via an AMPK-dependent pathway.

Sulfated Polysaccharides from Enteromorpha prolifera Attenuate Lipid Metabolism Disorders in Mice with Obesity Induced by a High-Fat Diet via a Pathway Dependent on AMP-Activated Protein Kinase.

BACKGROUND: Obesity-related metabolic diseases have recently evoked worldwide attention. Studies have demonstrated that Enteromorpha polysaccharide (EP) exerts lipid-lowering effects, but the underlying mechanism remains unclear. OBJECTIVES: We investigated whether EP regulates lipid metabolism disorders in mice with high-fat diet (HFD)-induced obesity via an AMP-activated protein kinase (AMPK)-dependent pathway. METHODS: Six-week-old male C57BL/6J mice (18 ± 2 g) were fed a normal diet (ND; 10% energy from fats) or an HFD (60% energy from fats) for 6 weeks to induce obesity and treated intragastrically with EP (200 mg/kg body weight) or distilled water (10 mL/kg body weight) for 8 weeks. Biochemical indicators, AMPK-dependent pathways, and lipid metabolism-related genes were evaluated to assess the effects of EP on HFD-induced lipid metabolism disorders. The essential role of AMPK in the EP-mediated regulation of lipid metabolism was confirmed using HFD-fed male Ampka2-knockout mice (aged 6 weeks; 17 ± 2 g) treated or not treated with the above-mentioned dose of EP. The data were analyzed by t-tests, 2-factor and 1-way ANOVAs. RESULTS: Compared to the ND, the HFD resulted in a greater body weight (24.3%), perirenal fat index (2.2-fold), and serum total cholesterol (24.66%) and LDL cholesterol (1.25-fold) concentrations (P < 0.05) and dysregulated the AMPK-dependent pathway and the expression of most lipid metabolism-related genes (P < 0.05). Compared to the HFD, EP treatment resulted in a lower perirenal fat index (31.22%) and LDL cholesterol concentration (23.98%) and partly reversed the dysregulation of the AMPK-dependent pathway and the altered expression of lipid metabolism-related genes (P < 0.05). Ampka2 knockout abolished the above-mentioned effects of EP in obese mice and the EP-mediated effects on the expression of lipid metabolism-related genes (P > 0.05). CONCLUSIONS: These findings suggest that EP can ameliorate lipid metabolism disorders in mice with HFD-induced obesity via an AMPK-dependent pathway.

Arsenic exposure diminishes ovarian follicular reserve and induces abnormal steroidogenesis by DNA methylation.

Arsenic contamination is a worldwide public health problem, and the effect of arsenic on male reproduction has been extensively studied; however, data on the biotoxicity of arsenic in terms of female reproduction are more scarce. In this study, a human-cell-animal translational strategy was applied to explore the effect of arsenic exposure on ovarian steroidogenesis and its potential mechanism. We conducted a 1:1 propensity score matched case-control study involving 127 diminished ovarian reserve (DOR) cases and 127 healthy controls. The ovarian follicular fluid levels of 21 metal elements, including arsenic, were measured. The results showed that there were significant differences in follicular fluid metal profiles between DOR patients and controls and that arsenic, molybdenum, and strontium played important roles in DOR progression [OR (95 % CI): 2.203 (1.385, 3.503), 2.308 (1.490, 3.575) and 2.922 (1.864, 4.580), respectively]. In the primary ovarian granulosa cell culture model, we found that treatment with 8 µM arsenic for 24 and 48 h induced a decrease in human granulosa cell viability. The estradiol (E2) level was significantly decreased after arsenic exposure (P < 0.05), which was dependent on significant alterations (P < 0.05) in key enzymes in steroidogenesis. In addition, a model for sodium arsenite exposure through water in rats from weaning to sexual maturity was established. We evaluated ovarian development by monitoring the estrous cycle, observing ovarian pathology, and calculating the follicular proportion. RT-qPCR, Western blotting, and bisulfite-sequencing PCR were used to investigate the effect of arsenic exposure on ovarian steroidogenesis and its possible mechanism. The results indicated that steroidogenic factor-1 (SF-1) was an important target of the steroidogenesis disorder induced by arsenic exposure. Arsenic significantly increased the DNA methylation level (P < 0.05) in the promoter region of SF-1 to reduce its expression, subsequently decreasing the levels of steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage enzyme (CYP11A1), and aromatase (CYP19A1) (P < 0.05), leading to premature depletion of ovarian follicles.

Higher dietary inflammation potential and certain dietary patterns are associated with polycystic ovary syndrome risk in China: A case-control study.

The pathogenesis of polycystic ovary syndrome (PCOS) remains unclear; however, inflammation is involved in PCOS progression and can be regulated by diet. We therefore hypothesized that diet may play an important role in the process of PCOS. This study aimed to investigate specific dietary patterns associated with PCOS through a case-control study involving 527 participants and conducted in Fuzhou, China. The dietary inflammatory index (DII) was calculated using a dietary frequency questionnaire, and the dietary pattern was obtained through a principal component analysis (PCA). Logistic regression was used for risk estimation, and the correlations were investigated by partial correlation analysis. The PCA identified a Mediterranean diet, a meat-egg diet, a shellfish-shrimp-dairy diet, and a staple food-soybean diet. The meat-egg (odds ratio [OR] = 1.404; 95% confidence interval [CI], 1.163-1.695) and shellfish-shrimp-dairy (OR = 1.287; 95% CI, 1.057-1.568) diets increased the risk of PCOS. The Mediterranean diet (OR = 0.759; 95% CI, 0.624-0.922) was identified as a protective factor and was negatively correlated with the DII. The DII scores ranged from -4.64 to 4.79 and were positively correlated with the risk of PCOS (OR = 1.141; 95% CI, 1.050-1.240). After adjusting for covariates, the platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and DII were positively correlated in PCOS (P < .001, P = .001, and P < .001, respectively). In conclusion, certain dietary patterns are associated with PCOS. Pro-inflammatory diets increase the risk of PCOS, and the DII was negatively correlated with the Mediterranean diet and positively correlated with the PLR, NLR, and SII.

Long Noncoding RNA Plasmacytoma Variant Translocation 1 Regulates Cisplatin Resistance via miR-3619-5p/TBL1XR1 Axis in Gastric Cancer.

Background: Chemoresistance greatly hinders the treatment of gastric cancer (GC). Long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been corroborated to be involved in chemoresistance in diverse cancers, including GC. The authors' aim was to investigate the underlying molecular mechanism of PVT1 in cisplatin (DPP) resistance in GC. Methods: Quantitative real-time polymerase chain reaction was conducted to detect the expression levels of PVT1, microRNA (miR)-3619-5p, and transducin beta like 1 x-linked receptor 1 (TBL1XR1) in DDP-resistant GC tissues and cells. 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry assay were used to check cell viability, half inhibition concentration (IC50), and apoptosis, respectively. The abilities of cell migration and invasion were evaluated by transwell assay. The protein levels of drug resistance-related proteins permeability glycoprotein (P-gp), glutathione s-transferase pi (GST-π), multidrug resistance-associated protein, and TBL1XR1 in samples were measured by Western blot. A xenograft tumor model was established to investigate the biological function of PVT1 in vivo. The starBase site was utilized to predict binding sites between miR-3619-5p and PVT1 or TBL1XR1, and the dual-luciferase reporter assay was performed to verify the interaction. Results: The levels of PVT1 and TBL1XR1 were significantly upregulated in DPP-resistant GC tissues and cells, while miR-3619-5p was notably declined. Knockdown of PVT1 enhanced DPP sensitivity of DPP-resistant GC cells. Also, knockdown of PVT1 enhanced the sensitivity of DPP-resistant GC cells to DPP and inhibited tumor growth in vivo. Meanwhile, PVT1 silencing decreased the expression of drug-resistant proteins. Moreover, PVT1 interacted with miR-3619-5p, and TBL1XR1 was a target of miR-3619-5p. Further studies indicated that downregulation of miR-3619-5p transposed PVT1 silencing- or TBL1XR1 silencing-mediated effects on viability, apoptosis, migration, and invasion of DPP-resistant GC cells. Conclusions: PVT1 silencing attenuated the DPP resistance in GC by downregulating TBL1XR1 via sponging miR-3619-5p.

Overexpression of microRNA-620 facilitates the resistance of triple negative breast cancer cells to gemcitabine treatment by targeting DCTD.

Patients with triple negative breast cancer (TNBC) have a poor survival rate following chemotherapy due to drug resistance. Notably, the molecular mechanism of drug resistance remains elusive. Between December 2011 and December 2014, 36 TNBC samples were obtained from Liaocheng People's Hospital. Three gemcitabine-resistant MDA-MB-231 cell lines (MDA-MB-231rGEM1, MDA-MB-231rGEM2 and MDA-MB-231rGEM3) were obtained by exposure of MDA-MB-231 cells to increasing concentrations of gemcitabine for >12 months. Reverse transcription-quantitative polymerase chain reaction was performed to detect the expression levels of specific genes, including microRNA (miR)-620, ATP-binding cassette sub-family B member 1 (ABCB1), ABCC10, cytidine monophosphate kinase, deoxycytidine monophosphate deaminase (DCTD), nucleoside diphosphate kinase 1 (NME1), ribonucleoside-diphosphate reductase large subunit (RRM1) and RRMB2. Western blot analysis was performed to assess the protein expression levels of DCTD. Furthermore, cell proliferation was assessed using a Cell Counting Kit-8 assay and cell apoptosis was detected using an Annexin V/Dead Cell Apoptosis kit. Interactions between miR-620 and DCTD were predicted using TargetScan and detected with the dual luciferase reporter assay. Elevation of miR-620 expression levels were detected in two of the assessed gemcitabine-resistant MDA-MB-231 cell lines compared with MDA-MB-231 cells. Gemcitabine induced significant elevation of miR-620 in MDA-MB-231 cells. An increase of DCTD at mRNA and protein expression levels in MDA-MB-231rGEM1 cells was observed compared with those in MDA-MB-231 cells. Results suggested that DCTD was directly regulated by miR-620. Inhibition of miR-620 and overexpression of DCTD reversed gemcitabine resistance in MDA-MB-231rGEM1 cells via inducing cell apoptosis and cell growth arrest. A negative correlation was identified between miR-620 and DCTD mRNA expression levels in patients with TNBC. The present results demonstrated that overexpression of miR-620 could contribute to the development of gemcitabine resistance in patients with TNBC via the direct downregulation of DCTD.

Sulfated polysaccharide from Enteromorpha prolifera increases hydrogen sulfide production and attenuates non-alcoholic fatty liver disease in high-fat diet rats.

Enteromorpha prolifera is an edible alga and previous studies have indicated that E. prolifera polysaccharide (EP) attenuates non-alcoholic fatty liver disease (NAFLD) in high-fat diet rats. Hydrogen sulfide (H2S) has recently been found to exert many physiological effects. The purpose of this study was to evaluate whether EP prevents NAFLD via regulation of H2S production. EP was orally administered to high-fat diet rats for 5 weeks. Treatment with EP (200 mg per kg body weight per d) significantly increased the serum H2S level and reduced the serum triglyceride level (p < 0.05) in rats fed a high-fat diet. These effects were similar to those observed with NaHS, a H2S donor. Real-time PCR and western blotting analysis revealed that EP significantly upregulated hepatic mRNA and protein expression of cystathionine-ß-synthase, which is the enzyme responsible for H2S production. These results indicate that EP decreases the serum TG level by increasing H2S production, suggesting that EP may be beneficial for the treatment of NAFLD and may reduce the risk of cardiovascular disease.

Polysaccharide-based micro/nanocarriers for oral colon-targeted drug delivery.

Oral colon-targeted drug delivery has attracted many researchers because of its distinct advantages of increasing the bioavailability of the drug at the target site and reducing the side effects. Polysaccharides that are precisely activated by the physiological environment of the colon hold greater promise for colon targeting. Considerable research efforts have been directed towards developing polysaccharide-based micro/nanocarriers. Types of polysaccharides for colon targeting and in vitro/in vivo assessments of polysaccharide-based carriers for oral colon-targeted drug delivery are summarised. Polysaccharide-based microspheres have gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon (colon cancer, inflammatory bowel disease (IBD), amoebiasis and irritable bowel syndrome (IBS)), but also for it's potential for the delivery of anti-rheumatoid arthritis and anti-chronic stable angina drugs. Besides, Polysaccharide-based micro/nanocarriers such as microbeads, microcapsules, microparticles, nanoparticles, nanogels and nanospheres are also introduced in this review.

Self-emulsifying drug delivery system and the applications in herbal drugs.

Herbal drugs have been used for thousands of years in the east and have had a recent resurgence in popularity among consumers in the west. However, most of herbal drug are poorly soluble and have hydrophobic properties and poor distribution, leading to reduced bioavailability and hence decreased treatment efficacy, requiring repeated administration or increased dose. In the past few decades, considerable attention has been focused on the development of self-emulsifying drug delivery system (SEDDS) for herbal drugs. SEDDS is isotropic and thermodynamically stable solutions consisting of oil, surfactant, co-surfactant and drug that can spontaneously form oil-in-water micro/nanoemulsion when mixed with water under gentle stirring. The formulation can be a viable alternative to classical formulations to take advantage of their lipophilic nature and to solve their problems of poor solubility, poor bioavailability, low oral absorption and instability. The mechanism of self-emulsification, solubility studies, construction of phase diagram, optimization and characterization of herbal drugs-loaded SEDDS formulation and in situ absorption evaluation of herbal drugs in rat intestine are presented in our article.