Administration of Gracilariopsis lemaneiformis polysaccharide attenuates cisplatin-induced inflammation and intestinal mucosal damage in colon-26 carcinoma tumor-bearing mice.

BACKGROUND: Our preliminary research revealed that the polysaccharide GP90 from Gracilariopsis lemaneiformis enhanced the antitumor effect of cisplatin, indicating that GP90 may increase the chemotherapeutic sensitivity. However, it is still necessary to fully understand whether GP90 can also improve the intestinal barrier dysfunction and systemic inflammation induced by cisplatin. RESULTS: GP90 has been demonstrated to inhibit the excessive release of nitirc oxide, interleukin (IL)-6, IL-1ß and tumor necrosis factor (TNF)-α induced by lipopolysaccharide in RAW264.7 cells. In vivo, GP90 effectively ameliorated the decrease in the serum CD4+ /CD8+ T-cell ratio induced by cisplatin and significantly reduced the increase in the inflammatory cytokines, CD4+ Foxp3+ , CD4+ granzyme B+ and CD4+ TNF-α induced by cisplatin. Furthermore, when combined with cisplatin, GP90 increases the protein expression levels of mucin-2 and zonula occludens-1 in the mouse small intestine. Additionally, GP90 combined with cisplatin has a modulatory effect on the intestinal microbiota by elevating the Firmicutes-to-Bacteroidetes ratio and the relative abundance of beneficial microorganisms (Lachnospiraceae bacterium), at the same time as reducing the abundance of cisplatin specific Bacteroides acidifaciens and elevating the content of butyric acid and isobutyric acid. CONCLUSION: Collectively, these findings indicate that GP90 potentially mitigates inflammation and protects the intestinal barrier in tumor-bearing organisms undergoing chemotherapy. © 2024 Society of Chemical Industry.

Tuna trimmings (Thunnas albacares) hydrolysate alleviates immune stress and intestinal mucosal injury during chemotherapy on mice and identification of potentially active peptides.

In this study, Tuna trimmings (Thunnas albacares) protein hydrolysate (TPA) was produced by alcalase. The anti-tumor synergistic effect and intestinal mucosa protective effect of TPA on S180 tumor-bearing mice treated with 5-fluorouracil (5-FU) chemotherapy were investigated. The results showed that TPA can enhance the anti-tumor effect of 5-FU chemotherapy, as evident by a significant reduction in tumor volume observed in the medium and high dose TPA+5-FU groups compared to the 5-FU group (p < 0.001). Moreover, TPA significantly elevated the content of total protein and albumin in all TPA dose groups (p < 0.01, p < 0.001), indicating its ability to regulate the nutritional status of the mice. Furthermore, histopathological studies revealed a significant increase in the height of small intestinal villi, crypt depth, mucosal thickness, and villi area in the TPA+5-FU groups compared to the 5-FU group (p < 0.05), suggesting that TPA has a protective effect on the intestinal mucosa. Amino acid analysis revealed that TPA had a total amino acid content of 66.30 g/100 g, with essential amino acids accounting for 30.36 g/100 g. Peptide molecular weight distribution analysis of TPA indicated that peptides ranging from 0.25 to 1 kDa constituted 64.54%. LC-MS/MS analysis identified 109 peptide sequences, which were predicted to possess anti-cancer and anti-inflammatory activities through database prediction. Therefore, TPA has the potential to enhance the antitumor effects of 5-FU, mitigate immune depression and intestinal mucosal damage induced by 5-FU. Thus, TPA could be serve as an adjuvant nutritional support for malnourished patients undergoing chemotherapy.

Structural characterization of a sulfated polysaccharide from Gracilariopsis lemaneiformis and its potentiation of cisplatin antitumor activity in Colon-26 carcinoma tumor-bearing mice by inducing ferroptosis.

Ferroptosis, a form of regulated cell death caused by iron-mediated lipid peroxidation, has become a potential strategy to overcome drug resistance and improve the efficacy of traditional cancer treatments. In this study, we investigated whether treatment with the combination of Gracilariopsis lemaneiformis polysaccharides and cisplatin (CP) potentiated the antitumor activity in a Colon-26 carcinoma tumor-bearing mouse model by ferroptosis activation. The G. lemaneiformis polysaccharide GP90 was mainly composed of (1→3) linked 4-O-sulfate-ß-D-galactose and (1→4) linked 3,6-anhydro-α-L-galactose with a molecular weight of 12.45 kDa. Compared with the CP group, the combination of GP90 and CP significantly suppressed tumor growth. Based on the transcriptomic and metabolomic analyses of tumor tissue, GP90 enhanced the antitumor effect of CP by promoting ferroptosis and regulating ferroptosis-related metabolic pathways. Moreover, the accumulation of 4-hydroxy-2-nonenal (4-HNE) and down-regulation of the expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (Gpx4) were verified by immunohistochemistry staining. Finally, gene set enrichment analysis showed that positive immunoregulatory pathways were significantly enriched in the GP90 and CP combination group. Our results indicate that GP90 potentiates chemotherapy sensitivity by targeting the transferrin receptor and SLC7A11/Gpx4 pathway to induce ferroptosis, which might be a useful therapeutic target in colorectal cancer patients.

Antidiabetic effects of protein hydrolysates from Trachinotus ovatus and identification and screening of peptides with α-amylase and DPP-IV inhibitory activities.

In the present study, the antidiabetic properties of Trachinotus ovatus protein hydrolysates (TOH) in streptozotocin-induced diabetic mice were investigated, and peptides with α-amylase (AAM) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities were identified and screened. The results showed that TOH alleviated body weight loss, polyphagia, blood glucose elevation and insulin secretion decline in diabetic mice. After 4 weeks of TOH administration, random blood glucose (RBG) decreased significantly. The TOH groups showed a dose-dependent reduction in fasting blood glucose (FBG), especially in the high-dose TOH group, which reduced FBG by 58% versus the effect of metformin. Moreover, TOH exerted a remarkable protective effect on hepatorenal function, as evidenced by increased superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) and decreased serum urea levels. Histopathological studies confirmed that TOH can significantly protect the kidney and pancreas from histological changes, which was of great benefit for ensuring the normal secretion of insulin and preventing the occurrence of complications such as diabetic nephropathy. Two fractions with higher inhibitory activity against AAM and DPP-IV, F4 and F6, were obtained from the ultrafiltration of TOH-2 (≤3 kDa). A total of 19 potentially active peptides from F4 and 3 potentially active peptides from F6 were screened by LC‒MS/MS combined with bioinformatic analysis. These peptides are small molecular peptides composed of 2-6 amino acids, rich in characteristic amino acids such as proline, arginine, phenylalanine and asparagine, and contain high proportions of peptides (68% for F4, 67% for F6) with hydrophobicity ≥50%. They offer potent antidiabetic potential and could potentially bind to the active sites in the internal cavities of the target enzymes AAM and DPP-IV. In summary, this study revealed for the first time the antidiabetic effects of protein hydrolysates of Trachinotus ovatus and their derived peptides, which are promising natural ingredients with the potential to be used for the treatment or prevention of diabetes.

Purification and Identification of Novel Myeloperoxidase Inhibitory Antioxidant Peptides from Tuna (Thunnas albacares) Protein Hydrolysates.

Antioxidative peptides that inhibit myeloperoxidase (MPO) enzyme activity can effectively defend against oxidative stress damage. The antioxidant peptides from tuna protein were produced using alcalase hydrolysis and purified by ultrafiltration and Sephadex G-15, and the fractions with the highest free radicals scavenging ability and oxygen radical absorbance capacity (ORAC) values were sequenced using HPLC-MS/MS. Fifty-five peptide sequences were identified, 53 of which were successfully docked into MPO. The representative peptide ACGSDGK had better antioxidant activity and inhibition of MPO chlorination and peroxidation than the reference peptide hLF1-11. The docking model further showed intense molecular interactions between ACGSDGK and MPO, including hydrogen bonds, charge, and salt bridge interactions, which occluded the active site and blocked the catalytic activity of MPO. These results suggested that the antioxidant peptide ACGSDGK has the potential to inhibit oxidative stress and alleviate inflammation in vivo because of its inhibitory effect on the MPO enzyme.

Hypolipidemic effects of protein hydrolysates from Trachinotus ovatus and identification of peptides implied in bile acid-binding activity using LC-ESI-Q-TOF-MS/MS.

In the present work, analysis of the hypolipidemic properties of Trachinotus ovatus protein hydrolysates (TOPHs) and identification of peptides with bile acid-binding activity were performed. Hydrolysates prepared by trypsin digestion exhibited the highest in vitro bile acid-binding capacities compared with hydrolysates prepared with the other four proteases and were mainly composed of small peptides and amino acids with molecular weights <3 kDa, accounting for 77.30%. Among the five ultra-filtration fractions of TOPHs, TOPHs-5 (<3 kDa) exhibited the highest in vitro bile acid-binding capacity, which was equivalent to 77.97% of cholestyramine at the same concentration. A total of 68 peptides were identified from TOPHs-5 by LC-ESI-Q-TOF-MS/MS and 9 of them had hydrophobicity of more than 60%. These highly hydrophobic peptides might be associated with the bile acid-binding activity of TOPHs-5. In vivo experiments indicated that the TOPHs could effectively reduce total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and the atherogenic index (AI), while they could evidently increase the high-density lipoprotein cholesterol (HDL-C) content. Furthermore, TOPHs exerted a marked protective effect on hepatorenal function, as evidenced by decreased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatinine (CREA). Histopathological studies confirmed that TOPHs evidently protected the liver from histological alterations. In summary, for the first time, hypolipidemic effects and subsequential identification were obtained from TOPHs, which are promising natural ingredients that could potentially be employed in the management of hyperlipidemia.

Composition characterization of oyster polysaccharides from Crassostrea hongkongensis and their protective effect against H2O2-induced oxidative damage in IEC-6 cells.

The proliferative activity of oyster polysaccharides in intestine epithelial cells (IEC-6) alleviated 5-fluorouracil-induced intestinal inflammation. In this study, we aimed to measure the ability of oyster polysaccharides to promote IEC-6 cell migration and antioxidant activity and further describe their cytoprotective effect on H2O2-challenged IEC-6 cells. The C30-60% fraction of polysaccharides (CHP2) showed rapid stimulation of IEC-6 cell migration after wounding. Then, CHP2 was fractionated into four fractions, namely, CHP2-1, CHP2-2, CHP2-3 and CHP2-4. The CHP2-3 fraction possessed high scavenging activities against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC), in comparison with other fractions. And CHP2-3 was heteropolysaccharide with sulfuric esters, and it was mainly composed of glucose, galactose and arabinose and had an average molecular weight of 41.81 kDa. Pretreatment with CHP2 and CHP2-3 significantly improved the survival rate of H2O2-treated IEC-6 cells, and reduced intracellular reactive oxygen species (ROS) levels. Moreover, CHP2-3 also significantly decreased H2O2-mediated increases in the secretion of interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), and attenuated nuclear factor-κB (NF-κB) p65 activation. These results indicate that CHP2-3 may play a vital role in reducing oxidative damage in IEC-6 cells via radical scavenging, decreasing proinflammatory factors secretion, inhibiting the NF-κB pathway, and thus, reducing cell apoptosis.

Protective Effects of Enteral Nutrition Supplemented with Crassostrea hongkongensis Polysaccharides Against 5-Fluorouracil-Induced Intestinal Mucosal Damage in Rats.

Chemotherapeutics, including 5-fluorouracil (5-FU), often damage the intestinal mucosal barrier and cause intestinal mucositis (IM). Supplementation with immunoregulatory polysaccharides from Crassostrea hongkongensis has been shown to positively influence the effectiveness and toxicity of 5-FU. Therefore, we studied the effects of oyster polysaccharides on 5-FU-induced intestinal mucosal damage in rats. The C30-60% ethanol-precipitated fraction of polysaccharides promoted IEC-6 cell proliferation and exhibited a maximal effect at a 0.0195 mg/mL concentration. Moreover, treatment with C30-60% polysaccharide-based nutrition formula (OPNF) partially prevented the 5-FU-induced degenerative changes in the histology and ultrastructure of small intestinal mucosa. In addition, the endotoxin level of rats fed with 5-FU and OPNF decreased to the normal control level. Furthermore, the 5-FU-induced increase of proinflammatory cytokine interleukin (IL)-2 and the decrease of anti-inflammatory cytokine IL-10 level in the peripheral blood were significantly attenuated by OPNF administration. In conclusion, Oyster C30-60% polysaccharides can ameliorate 5-FU-induced IM by partially preventing mucosal damage, reducing inflammation, and promoting immunity.

Lactogenic Activity of an Enzymatic Hydrolysate from Octopus vulgaris and Carica papaya in SD Rats.

The traditional Chinese medicine theory believes that octopus papaya soup can stimulate milk production in lactating women. The objective of this study was to determine whether dietary supplementation with an enzymatic hydrolysate of Octopus vulgaris and Carica papaya (EHOC) could increase milk production and nutritional indexes in Sprague Dawley (SD) rats. Female SD rats (n = 24) were fed a control diet (n = 8), EHOC-supplemented diet, or a positive control diet (Shengruzhi) from day 10 of pregnancy to day 10 of lactation. Maternal serum, mammary gland (day 10 of lactation), milk, and pup weight (daily) were collected for analysis. Results showed that the EHOC diet obviously elevated daily milk yield and pup weight compared to the control group (P < .05). The EHOC diet was found to increase the concentration of prolactin (PRL), progesterone (P), estradiol (E2), and growth hormone (GH) significantly in the circulation and mammary gland. Mammary glands of EHOC-treated dams showed clear lobuloalveolar development and proliferation of myoepithelial cells, but no striking variations were observed among the groups. Furthermore, the nutrition content and immune globulin concentration in the milk of EHOC-supplemented dams were higher than those of the control group, especially the cholesterol, glucose, and IgG were higher by 44.98% (P < .001), 42.76% (P < .01), and 42.23% (P < .01), respectively. In conclusion, this article demonstrates that EHOC administration has beneficial effects on milk production in the dams and on performance of the dam and pup. These results indicate that EHOC could be explored as a potentially lactogenic nutriment for lactating women.

Ultrasonic-assisted production of antioxidative polysaccharides from Crassostrea hongkongensis.

The beneficial effects of oyster extract against various disorders and diseases induced by oxidative stress have aroused great interest. In this article, ultrasonic-assisted enzymolysis was employed to produce polysaccharides of Crassostrea hongkongensis (CHP) and their antioxidant activity was investigated. A single-factor experiment and then a four-factor, three-level Box-Behnken design were first used to optimize ultrasonic extraction for polysaccharides. On the basis of ridge analysis, the optimum conditions are obtained as ultrasonic treatment time of 24 min, power of 876 W, temperature of 49°C, and material-solvent ratio of 1:6 (w/v). It is found that ultrasound pretreatment before protease hydrolysis was a great help to improve CHP yield and purity, especially more favorable with flavorzyme, neutrase, alcalase, and pepsin. Furthermore, the polysaccharide fraction, which was obtained by ultrasonic pretreatment and then alcalase hydrolysis at the conditions of 3000 U/g, 55°C, pH 8.0, for 4 hr, exhibited an obvious scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (98.48 ± 0.55% and 99.20 ± 0.12%, respectively) and a lenoleic acid peroxidation inhibition effect (85.48 ± 0.65%) at a concentration of 5.0 mg/mL. These results reveal the potential application of CHP in functional food and nutraceuticals.