Osteoporosis is a common disease in the elderly, which is related to fracture healing delay. In this study, the effects of treatment with sialoglycoprotein isolated from the eggs of Gadus morhua (Gm-SGP) on tibial fracture healing in ovariectomized (OVX) osteoporotic female C57BL/6J mice for 56 days post-fracture were investigated. The result showed that Gm-SGP treatment significantly increased serum angiogenic factors and bone formation markers on day 5 and 11 post-fracture when compared with the OVX group. In addition, histological results in the Gm-SGP group showed a stronger endochondral ossification, a stronger bony consolidation and a stronger bony callus remodeling capability on day 11, 24 and 35 post-fracture, respectively, in comparison with the OVX group. Meanwhile, micro-computerized tomography revealed that the Gm-SGP group had stronger bony callus remodeling capability as evidenced by higher BV/TV and Tb.N but lower Tb.Sp and shorter lengths of callus maximum cross section than the OVX group on day 24 post-fracture. Besides, the tibial callus bending stiffness was significantly enhanced in the Gm-SGP group as compared with the OVX group on day 56 post-fracture. Moreover, gene expression suggested that Gm-SGP promoted vascular invasion and endochondral ossification on day 11 post-fracture as well as bone formation on day 11 and 24 post-fracture via up-regulating the expression of angiogenesis factors (including VEGF, PDGF and Ang1), entochondrostosis factors (including Col2a1, Aggrecan, Col10a1 and MMP-13) and osteogenesis markers (including Col1a1, BMP-2 and OCN). This research suggests that Gm-SGP significantly improve fracture healing which is delayed by OVX-induced osteoporosis. The present study may contribute to providing important implications for the utilization of Gm-SGP from fish eggs as a functional food to enhance fracture healing.

•The alleviating effect of EPA-PC on non-alcoholic fatty liver disease was tested.•EPA-PC regulated key enzyme activities in fatty acid synthesis, transport and β-oxidation.•The mechanism involved regulating transcriptions of AMPK and its target genes.•Our study predicted EPA-PC as a novel agent for non-alcoholic fatty liver disease.The lipid-lowering effects of eicosapentaenoic acid-containing phosphatidylcholine (EPA-PC) from sea cucumber in rat models of non-alcoholic fatty liver disease (NAFLD) were investigated. Oral administration of EPA-PC to orotic acid (OA)-fed mice lowered the liver-to-body weight ratio, serum and hepatic triacylglycerol (TG) and total cholesterol (TC) levels, and high-density lipoprotein cholesterol (HDLC)/TC ratio. EPA-PC also increased the proportion of polyunsaturated fatty acids (PUFA) in serum and hepatic lipids. To elucidate the possible mechanism of action underlying the lipid-lowering effects of EPA-PC, the key enzymes and transcriptional factors involved in fatty acid biosynthesis, transport, and β-oxidation were investigated. The mRNA expressions of SREBP-1c, PPARα, and AMPK, as well as of their target genes, were detected. The results showed that EPA-PC could significantly ameliorate lipid accumulation by suppressing lipid biosynthesis and promoting fatty acid transport and β-oxidation. Overall, our findings revealed that EPA-PC could alleviate NAFLD.

In the current study, ovariectomized (OVX) rats and the senescence-accelerated mouse strain P6 (SAMP6) were employed to establish models of postmenopausal osteoporosis and senile osteoporosis, respectively. The effects of treatment with sialoglycoprotein isolated from the eggs of Carassius auratus (Ca-SGP) on these two types of osteoporosis were investigated in vivo. Results showed that Ca-SGP significantly increased bone mineral density, ameliorated trabecular bone microstructure, and improved bone biomechanical properties in both OVX rats and SAMP6. The osteogenesis related Wnt/β-catenin pathway was targeted to study the underlying mechanism of Ca-SGP activity. In postmenopausal osteoporosis, Ca-SGP suppressed the activation of Wnt/β-catenin signal via down-regulating the expression of key genes including LRP5, β-catenin, and Runx2, suggesting that overactive osteogenesis was controlled by Ca-SGP. The bone formation was sharply weakened in senile osteoporosis, whereas Ca-SGP treatment promoted osteoblast activity by stimulating the Wnt/β-catenin signal. In conclusion, Ca-SGP ameliorated these two types of osteoporosis by normalizing bone anabolism.

•Anti-osteoporotic activity of Ca-SGP is reported for the first time.•Ca-SGP promoted osteogenesis.•Ca-SGP increased OPG/RANKL ratio in MC3T3-E1 cells and bilateral ovariectomized rats.•Ca-SGP improved tibia BMD of osteoporotic rats induced by bilateral ovariectomy.•Ca-SGP is a novel and significant functional factor for the treatment of osteoporosis.The anti-osteoporotic activities of a sialoglycoprotein isolated from the eggs of Carassius auratus (Ca-SGP). Ca-SGP was composed of 14.33% protein, 62.81% hexose, and 19.72% N-acetylneuraminic acid (Neu5Ac). In vitro experimental results showed that Ca-SGP significantly increased MC3T3-E1 pre-osteoblastic cells' proliferation activities, promoted cell differentiation and mineralization as evidenced by increasing the contents or activities of major markers, i.e. collagen type I (COL I), osteocalcin (OCN), alkaline phosphatase (ALP) and bone nodules. Ca-SGP significantly augmented protein expressions and secretions of bone morphogenetic protein 2 (BMP-2) and osteoprotegerin (OPG), meanwhile, decreased that of receptor activator of nuclear factor κB ligand (RANKL). In vivo experimental data further revealed that Ca-SGP significantly reduced bone turnover rates, increased serum OPG/RANKL ratio and enhanced tibia bone mineral density (BMD) in the model rats of ovariectomized (OVX)-induced osteoporosis. These results suggest that Ca-SGP could improve osteoporosis by promoting osteogenesis and inhibiting bone resorption via increasing OPG/RANKL ratio, which indicates that Ca-SGP is a potential candidate functional factor for osteoporosis prevention.

There is mounting evidence demonstrating causative links between hyperglycemia, oxidative stress, and insulin resistance, the core pathophysiological features of type 2 diabetes mellitus. Using a combinational approach, we synthesized a vanadium–antioxidant (i.e., l-ascorbic acid) complex and examined its effect on insulin resistance and oxidative stress. This study was designed to examine whether vanadyl(IV)-ascorbate complex (VOAsc) would reduce oxidative stress, hyperglycemia, and insulin resistance in high-fat high-sucrose diet (HFSD)-induced type 2 diabetes in mice. Male C57BL/6J mice were fed a HFSD for 12 weeks to induce insulin resistance, rendering them diabetic. Diabetic mice were treated with rosiglitazone, sodium l-ascorbate, or VOAsc. At the end of treatment, fasting blood glucose, fasting serum insulin, homeostasis model assessment-insulin resistance index, and serum adipocytokine levels were measured. Serum levels of nitric oxide (NO) parameters were also determined. The liver was isolated and used for determination of malondialdehyde, reduced glutathione, and catalase levels, and superoxide dismutase and glutathione peroxidase activities. VOAsc groups exhibited significant reductions in serum adipocytokine and NO levels, and oxidative stress parameters compared to the corresponding values in the untreated diabetic mice. The results indicated that VOAsc is non-toxic. In conclusion, we identified VOAsc as a potentially effective adjunct therapy for the management of type 2 diabetes.

In the current study, we investigated the improvement of phosphorylated peptides from Antarctic krill Euphausia superba (PP-AKP) on osteoporosis in ovariectomized rats. PP-AKP was supplemented to ovariectomized Sprague–Dawley rats for 90 days. The results showed that PP-AKP treatment remarkably prevented the reduction of bone mass and improved cancellous bone structure and biochemical properties. PP-AKP also significantly decreased serum contents of tartrate-resistant acid phosphatase (TRACP), cathepsin K (Cath-k), matrix metalloproteinases-9 (MMP-9), deoxypyridinoline (DPD), C-terminal telopeptide of collagen I (CTX-1), Ca, and P. Mechanism investigation revealed that PP-AKP significantly increased the osteoprotegerin (OPG)/receptor activator of nuclear factor κB ligand (RANKL) ratio in mRNA expression, protein expression, and serum content. Further research suggested that NF-κB signaling pathways were inhibited by suppressing the mRNA and protein expressions of nuclear factor of activated T-cells (NFATc1) and tumor necrosis factor receptor-associated factor 6 (TRAF6), diminishing the mRNA expression and phosphorylation of nuclear factor κB p65 (NF-κB p65), three key transcription factors in NF-κB pathways. These results suggest that PP-AKP can improve osteoporosis by inhibiting bone resorption via suppressing the activation of osteoclastogenesis related NF-κB pathways.

Both adipocyte hypertrophy and hyperplasia lead to obesity. Here, we isolated cerebrosides from the sea cucumber Cucumaria frondosa (CFC) and examined its anti-adipogenic activity in vitro. CFC inhibited the lipid accumulation of 3T3-L1 cells and suppressed PPARγ and C/EBPα expressions, proving its anti-adipogenic activity. Furthermore, CFC suppressed lipogenesis in mature adipocytes. The WNT/β-catenin pathway acts as an anti-adipogenic factor. CFC enhanced β-catenin expression, promoted its nuclear translocation and up-regulated the expression of CCND1 and c-myc, two target genes of β-catenin. Moreover, after cells were treated with the β-catenin inhibitor 21H7, β-catenin nuclear translocation and transcription activity can be recovered by CFC. These findings suggested that CFC promoted the activation of the WNT/β-catenin pathway. Besides, CFC enhanced the expressions of Fz1, LRP5 and LRP6, while it had no effect on the expressions of Wnt10b and GSK3β. These findings indicated that CFC exhibits anti-adipogenic activity through enhancing the activation of the WNT/β-catenin pathway, which was mediated by FZ and LRPs.

Fucoidan was extracted from the sea cucumber Acaudina molpadioides (Am-FUC), and its effect of improving insulin resistance was investigated in vitro and in vivo. Insulin resistance model 3T3-L1 adipocytes were established by treating with 20 ng/ml TNF-α for 24 h. Am-FUC significantly increased the glucose consumption, indicating that Am-FUC improved insulin resistance. Besides, Am-FUC up-regulated PKB/GLUT4 pathway in transcriptional level, enhanced phosphorylation of PI3K and PKB, promoted GLUT4 translocation, which indicated that the pathway was activated. In in vivo experiments, insulin resistance model mice were established by feeding a high-fat high-fructose diet. Am-FUC increased serum insulin level, decreased HOMA-IR, reduced fasting blood glucose level, and improved oral glucose tolerance ability, revealing that Am-FUC can still remit the insulin resistance in vivo. The protein expression levels and phosphorylation of PI3K and PKB in adipose tissue were in keeping with that in 3T3-L1 adipocytes. Combination of Am-FUC and rosiglitazone exerted better effect on improving insulin resistance. These findings suggested that Am-FUC improved the insulin resistance by activating the PKB/GLUT4 pathway.

•Repair of pancreatic islets by Cf-CHS are reported for the first time.•Cf-CHS inhibited hyperglycemia induced-pancreatic islets apoptosis.•Cf-CHS blocked cytochrome c release to cytoplasm from mitochondria.•Inactivation of mitochondrial pathway caused the inhibition of apoptosis by Cf-CHS.•Cf-CHS is a novel and significant functional factor for insulin resistant therapy.Hyperglycaemia can induce pancreatic islets apoptosis. We previously found that fucosylated chondroitin sulphate from Cucumaria frondosa (Cf-CHS) exhibited anti-hyperglycaemic effects; however, its effects on pancreatic islets are lacking. This study investigated the effects of Cf-CHS on inhibition pancreatic islets apoptosis in high-fat high-sucrose diet (HFSD)-induced insulin resistant mice for 19 weeks. Results showed that Cf-CHS significantly repaired HFSD-injured pancreatic islets, decreased blood glucose, insulin, TNF-α levels, and increased adiponectin level. Cf-CHS significantly reduced Bid, Bax, cytochrome c, caspase 9, and caspase 3 mRNA expressions, and increased Bcl-2 and Bcl-xL mRNA expressions. Cf-CHS also caused significant down-regulation of t-Bid, Bax, cytochrome c in cytoplasm, caspase 9, and cleaved-caspase 3 proteins, and up-regulation of Bcl-2 and Bcl-xL proteins. Furthermore, Cf-CHS enhanced the effects of rosiglitazone (RSG). These indicate that Cf-CHS inhibits pancreatic islets apoptosis via inhibition mitochondrial pathway. These findings may provide a dietary intervention hyperglycaemia-induced pancreatic islets apoptosis.

A novel fucoidan, which consists of a 1 → 3-linked tetrafucose repeating unit that is distinctive in its sulphation pattern, was isolated from the sea cucumber Acaudina molpadioides. In the present study, we examined the anti-adipogenic effect of the fucoidan from Acaudina molpadioides (Am-FUC) in vitro and in vivo. Results showed that Am-FUC exhibited an inhibitory effect on the proliferation and differentiation of 3T3-L1 cells. Am-FUC suppressed the differentiation of 3T3-L1 cells, decreasing the content of intracellular triglyceride by 34.07% at the concentration of 200 μg ml−1. In vivo experiments showed that the subcutaneous, perirenal and epididymal fat content of Am-FUC-treated mice were significantly reduced compared to the HFFD-fed mice. A reverse transcriptase-polymerase chain reaction assay revealed that Am-FUC significantly increased the mRNA expressions of Wnt/β-catenin pathway related factors, namely, Wnt10b, β-catenin, Fz and LRP5, and decreased that of the key transcriptional factors, such as SREBP-1c, PPARγ and C/EBPα. β-Catenin acts as an anti-adipogenic factor to inhibit the expression of PPARγ and C/EBPα, while SREBP-1c can promote the adipocyte differentiation by enhancing the activity of PPARγ. Western blotting results showed that Am-FUC significantly increased the protein level of the total β-catenin and nuclear β-catenin and suppressed that of the SREBP-1c. Am-FUC also significantly inhibited the mRNA expressions of the lipid synthesis related genes such as FAS and GPAT, while had no effect on that of the lipolysis related genes such as HSL and ATGL. These findings suggest that Am-FUC possesses marked anti-adipogenic activity by modulating the Wnt/β-catenin pathway and down-regulating the expression of SREBP-1c.

In this study, we investigated the improvement of fucosylated chondroitin sulfate (CHS) from the cucumber Acaudina molpadioides on hyperglycemia in skeletal muscle of insulin resistant mice. CHS, rosiglitazone (RSG), and their combinations were supplemented to high-fat high-sucrose diet (HFSD)-fed C57BL/6J mice for 19 weeks. The results showed that CHS treatment remarkably decreased blood glucose level and insulin resistance. The glucose metabolism-related genes expressions at the transcriptional level were apparently increased in skeletal muscle. Although the total protein expressions of IR-β, IRS-1, PI3K, PKB and GLUT4 in skeletal muscle were not affected, insulin-stimulated GLUT4 translocation and phosphorylation of Tyr-IR-β, Tyr612-IRS-1, p85-PI3K, Ser473-PKB, and Thr308-PKB were significantly increased by CHS supplement. Additionally, combination of CHS and RSG produced synergistic effects on anti-hyperglycemia. These results indicate that CHS can alleviate hyperglycemia via activation of the PKB/GLUT4 signaling pathway in skeletal muscle of insulin resistant mice.

Ds-echinoside A (DSEA), a non-sulfated triterpene glycoside, was isolated from the sea cucumber Pearsonothuria graeffei. In vitro and in vivo investigations were conducted on the effects of DSEA on tumor cell adhesion, migration, invasion, and angiogenesis. In this study, we found that DSEA inhibited the proliferation of human hepatocellular liver carcinoma cells Hep G2, with a half-maximal inhibitory concentration (IC50) of 2.65 μmol/L, and suppressed Hep G2 cell adhesion, migration, and invasion in a dose-dependent manner. DSEA also reduced tube formation of human endothelial cells ECV-304 on matrigel in vitro and attenuated neovascularization in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Immunocytochemical analysis revealed that DSEA significantly decreased the expression of matrix metalloproteinase-9 (MMP-9), which plays an important role in the degradation of basement membrane in tumor metastasis and angiogenesis. DSEA also increased the protein expression level of tissue inhibitor of metalloproteinase-1 (TIMP-1), an important regulator of MMP-9 activation. From the results of Western blotting, the expressions of nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) were found to be remarkably reduced by DSEA. These findings suggest that DSEA exhibits a significant antimetastatic activity through the specific inhibition of NF-κB-dependent MMP-9 and VEGF expressions.

•EPA-enriched phosphatidylcholine (Cucumaria-PC) is isolated from Cucumaria frondosa.•The anti-hyperglycemic effects of Cucumaria-PC are reported for the first time.•Cucumaria-PC augments the main genes transcription and translation in PI3K/PKB pathway.•The phosphorylation of IR, PI3K, PKB is also enhanced by Cucumaria-PC.•Cucumaria-PC is a novel, safe, and significant functional factor for diabetic therapy.Eicosapentaenoic acid-enriched phosphatidylcholine was isolated from the sea cucumber Cucumaria frondosa (Cucumaria-PC) and its effects on streptozotocin (STZ)-induced hyperglycemic rats were investigated. Male Sprague–Dawley rats were randomly divided into normal control, model control (STZ), low- and high-dose Cucumaria-PC groups (STZ + Cucumaria-PC at 25 and 75 mg/Kg·b·wt, intragastrically, respectively). Blood glucose, insulin, glycogen in liver and gastrocnemius were determined over 60 days. Insulin signaling in the rats' gastrocnemius was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The results showed that Cucumaria-PC significantly decreased blood glucose level, increased insulin secretion and glycogen synthesis in diabetic rats. RT-PCR analysis revealed that Cucumaria-PC significantly promoted the expressions of glycometabolism-related genes of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphoinositide 3-kinase (PI3K), protein kinase B (PKB), and glucose transporter 4 (GLUT4) in gastrocnemius. Western blotting assay demonstrated that Cucumaria-PC remarkably enhanced the proteins abundance of IR-β, PI3K, PKB, GLUT4, as well as phosphorylation of Tyr-IR-β, p85-PI3K, Ser473-PKB (P < 0.05 and P < 0.01). These findings suggested that Cucumaria-PC exhibited significant anti-hyperglycemic activities through up-regulating PI3K/PKB signal pathway mediated by insulin. Nutritional supplementation with Cucumaria-PC, if validated for human studies, may offer an adjunctive therapy for diabetes mellitus.

•Lipases TLIM was more effective than phospholipases and other lipases for esterification of GPC and n−3 PUFA.•Optimal conditions were a temperature of 45 °C, a mole ratio of 1:20 (GPC to n−3 PUFA) under vacuum for 64 h.•The 1-acyl-sn-glycero-3-lysophosphatidylcholine (2-LPC) was predominant in the reaction.The n−3 polyunsaturated fatty acids (PUFA)-rich lysophosphatidylcholine (LPC) was successfully synthesized by Thermomyces lanuginosus lipase (TL IM)-catalyzed esterification of glycerylphosphorylcholine (GPC) and n−3 PUFA-rich fatty acids in a solvent-free system. Effects of reaction temperature, enzyme loading and substrate mole ratio on the yield of LPC and incorporation of n−3 PUFA were evaluated. The acyl-specificities of five enzymes were tested for direct esterification of n−3 PUFA, and Lipozyme TL IM was found to be more effective than others for production of LPC with n−3 PUFA. Substrate mole ratio and reaction temperature, however, had no significant effect on the incorporation. The maximal yield of LPC was obtained under the following conditions: temperature 45 °C, enzyme loading 15% by weight and substrate mole ratio (GPC/n−3 PUFA) 1:20. Furthermore, the composition of products were further investigated in the study. The 1-acyl-sn-glycero-3-lysophosphatidylcholine (2-LPC) was predominant in the mixtures at early stages of reaction, whereas less increment of 2-acyl-sn-glycero-3-lysophosphatidylcholine (1-LPC) and PC was observed at later stages.