Cognition of polysaccharides from confusion to clarity: when the next "omic" will come?

With the accelerated pace of modern life, people are facing more and more health pressure. The study of polysaccharides seemed a good choice as a potential treasure trove. Polysaccharides, one of the four basic substances (proteins, nucleic acids, lipids and carbohydrates) that constitute life activities, are obviously an underrated macromolecular substance with great potential. Compared with protein and nucleic acid, the research of polysaccharides is still in the primary stage. The relationship between structure and function of polysaccharides is not clear. In this review, we highlighted the main methods of extraction, purification and structure identification of polysaccharides; summarized their biological activities including immunoregulation, hypoglycemic, anti-tumor, anti-virus, anti-coagulation, and so on. Particularly, the relationship between their structures and activities was described. In addition, the applications of polysaccharides in health food, medicine and cosmetics were also reviewed. This review can help polysaccharide researchers quickly understand the whole process of polysaccharides research, and also provide a reference for the comprehensive utilization of polysaccharides. We need to standardize the research of polysaccharides to make the experimental data more universal, and take it as important references in the review process. Glycomic may appear as the next "omic" after genomic and proteomic in the future. This review provides support for the advancement of glycomics.

Probiotic properties and proteomics analysis of ethanol-induced Lactococcus lactis subsp. lactis IL1403.

Our previous study indicated that ethanol-induced intracellular extracts (E-IEs) of Lactococcus lactis subsp. Lactis IL1403 (L. lactis IL1403) alleviated hangovers more effectively in mice than untreated intracellular extracts (U-IEs), but the material basis was unclear. Considering that stress-related proteins might play a significant role, the effects of ethanol induction on probiotic properties of L. lactis IL1403 and the associated stress response mechanism were initially explored in this study. E-IEs of L. lactis IL1403 showed better biological activities, significantly increased bacteria survival rates in oxidative stress environments, increased ADH activity, and enhanced proliferation in RAW264.7 and AML-12 cells. Proteomic analyses revealed that 414 proteins were significantly changed in response to ethanol induction. The expression of proteins involved in the universal stress response, DNA repair, oxidative stress response, and ethanol metabolism was rapidly upregulated under ethanol stress, and quantitative real-time PCR (qRT-PCR) results were consistent with proteomic data. KEGG pathway analysis indicated that citrate metabolism, starch and sucrose metabolism, and pyruvate metabolism were significantly enriched during ethanol stress to increase energy requirements and survival rates of stressed cells. Based on this observation, the active induction is an effective strategy for increasing the biological activity of L. lactis IL1403. Exploring the molecular mechanism and material basis of their functions in vivo can help us understand the adaptive regulatory mechanism of microorganisms.

Protective effect of the stressed supernatant from Lactococcus lactis subsp. lactis and its metabolic analysis.

There are numerous factors restricting wide application of lactic acid bacteria (LAB) in dairy industry, causing urgent demands for novel bioprotectants. Protective effects and metabolites of Lactococcus lactis subsp. lactis (L. lactis) from ultraviolet (UV)-induced supernatant were investigated and the protective mechanism was explored. The strain viability of the group treated with the supernatant of continuous UV irradiation (V1) and the group with intermittent UV irradiation (V2) was 8.45 and 14.13 times of the control group, respectively. Further exploration on the protective of L. lactis supernatant, under different dose of UV treatment, showed it was dose-dependent. The condition for the supernatant with best protective effect was vertical distance 50.00 cm, horizontal distance 25.00 cm, intermittent UV irradiation (30 s interval 30 s) for 4.5 min (V2), which was chose for untargeted metabolite analysis. And that in V1 was for comparative study. There were 181 up-regulated metabolites in V1 and 161 up-regulated metabolites in V2, respectively. Most of the up-regulated metabolites were related to secondary metabolite synthesis, environmental microbial metabolism, antibiotic synthesis and amino acid biosynthesis. Notably, production of dithiothreitol (DTT) in V2 was 65.2-fold higher than that in the control group. Trehalose in ABC transporter pathway was also up-regulated in the metabolites induced by UV. Results indicated that L. lactis could adapt to the UV stress by adjusting metabolic pathways and producing special metabolites to protect itself. This research offers the basis for robust strain development and contributes to initial study on potential bioprotectant.

Lef1 is transcriptionally activated by Klf4 and suppresses hyperoxia-induced alveolar epithelial cell injury.

PURPOSE: Bronchopulmonary dysplasia (BPD) is a long-term respiratory condition. More than a quarter of extremely premature newborns are harmed by BPD. At present, there are no apparent effective drugs or treatments for the condition. In this study, we aimed to investigate the functional role and mechanism of lymphoid enhancer-binding factor 1 (Lef1) in BPD in vitro. MATERIALS AND METHODS: Blood samples from BPD patients and healthy volunteers were gathered, and an in vitro model of BPD was developed in alveolar epithelial cells (AECs) MLE-12 induced by hyperoxia. Then expression of krüppel-like factor 4 (KLF4/Klf4) and LEF1/Lef1 were evaluated. After Lef1 overexpressing plasmid and the vector were transfected into hyperoxia-induced MLE-12 cells, cell proliferation assays were carried out. Cell apoptosis was investigated by a flow cytometry assay, and apoptosis related proteins Bcl-2, cleaved-caspase 3 and 9 were analyzed by a western blot assay. The binding between Klf4 and Lef1 promoter predicted on the JASPAR website was verified using luciferase and ChIP assays. For further study of the mechanism of Klf4 and Lef1 in BPD, gain-of-function experiments were performed. RESULTS: The mRNA levels of KLF4/Klf4 and LEF1/Lef1 were diminished in clinical BPD serum samples and hyperoxia-induced MLE-12 cells. Overexpression of Lef1 stimulated AEC proliferation and suppressed AEC apoptosis induced by hyperoxia. Mechanically, Klf4 bound to Lef1's promoter region and aids transcription. Moreover, the results of gain-of-function experiments supported that Klf4 could impede AEC damage induced by hyperoxia via stimulating Lef1. CONCLUSION: Klf4 and Lef1 expression levels were declined in hyperoxia-induced AECs, and Lef1 could be transcriptionally activated by Klf4 and protect against hyperoxia-induced AEC injury in BPD. As a result, Lef1 might become a prospective therapeutic target for BPD.

60Coγ induction improves the protective effect of Acetobacter pasteurianus against ionizing radiation in mice.

Exposure to ionizing radiation (IR) tends to cause serious health concerns. Thus, radioprotective agents are vital for the population exposed to radiation. As microorganisms have the advantages of fast reproduction and no geographical restrictions, direct microbe-based and environmental induction compounds are thriving radioprotectants resources. Oxidative system and oxidase in Acetobacter pasteurianus are unique and intriguing, the radioprotective effect of the cell-free extract from A. pasteurianus (APE) and 60Coγ-treated extract (IRE) were comparatively investigated in the present study. The survival rate of A. pasteurianus with IRE addition was 149.1% in H2O2 damage test, while that with APE was only 10.4%. The viability of 60Coγ-treated AML-12 cells was increased by 18.8% with IRE addition, yet APE showed no significant radioprotective effect. Moreover, in 60Coγ-treated mice, IRE could significantly protect the white blood cell, improve the liver index, and attenuate the injuries of immune organs in mice. Administration of IRE significantly raised the activities of superoxide dismutase (SOD) and reduced the products of lipid peroxidation. These results clarified that gavage with APE and IRE presented notable antioxidant and radioprotective efficacy. A. pasteurianus showed appealing potential to be novel radioprotective bioagents and 60Coγ treatment on microbe could be a new method for the development of better radioprotectant. KEY POINTS: • 60Coγ induction could improve the radioprotective effect of APE. • IRE protected white blood cell in mice under IR. • IRE products have broad application prospects in radioprotection based on microbes.

Radioprotective effect of radiation-induced Lactococcus lactis cell-free extract against 60Coγ injury in mice.

Ionizing radiation (IR) is widely used in the diagnosis and treatment of various cancers. However, IR can cause damage to human health by producing reactive oxygen species. Lactococcus lactis is a type of microorganism that is beneficial to human health and has a strong antioxidant capacity. In this study, the protective effect of normal and IR-induced L. lactis IL1403 cell-free extracts (CFE and IR-CFE, respectively) against oxidative damage in vitro and the radioprotective effect of IR-CFE in vivo was evaluated using 60Coγ-induced oxidative damage model in mice. Results showed that IR-CFE exhibited a stronger oxidative damage-protective effect than CFE for L. lactis IL1403 under H2O2 in vitro. Moreover, IR-CFE also showed strong radioprotective effect on hepatocyte cells (AML-12) under radiation condition, and the effect was better than that of CFE. Animal experiment indicated that IR-CFE could reduce the IR-induced damage to the hematopoietic system by increasing the number of white blood cells and red blood cells in peripheral blood of irradiated mice. It was also observed that IR-CFE could markedly alleviate the 60Coγ-induced oxidative stress via increasing the activities of superoxide dismutase and glutathione peroxidase, enhancing the levels of glutathione, and decreasing the contents of malondialdehyde in serum, liver, and spleen. In addition, IR-CFE also could reduce the activities of alanine transaminase and aspartate aminotransferase in serum, thereby reducing radiation damage to the liver. These results suggested that IR-CFE could be considered as potential candidates for natural radioprotective agents. This study provides a theoretical basis for improving the application of lactic acid bacteria.

Correlation analysis between CARMEN variants and alcohol-induced osteonecrosis of the femoral head in the Chinese population.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a complicated disease associated with trauma, hormone abuse and excessive alcohol consumption. Polymorphisms of long non-coding RNAs have been also linked with the development of ONFH. Our research aimed to explore the relationship between CARMEN (Cardiac Mesoderm Enhancer-Associated Non-Coding RNA) variants and ONFH risk. METHODS: Our study used Agena MassARRAY Assay to genotype 6 selected single nucleotide polymorphisms (SNPs) in 731 participants (308 alcohol-induced ONFH patients and 423 controls). We used odds ratios (ORs) and 95% confidence intervals (CIs) to calculate the effect of gene polymorphisms on the occurrence of alcohol-induced ONFH by logistic regression analysis and haplotype analysis. RESULTS: Our overall analysis illustrated that rs13177623 and rs12654195 had an association with a reduced risk of ONFH after adjustment for age and gender. We also found that rs13177623, rs12654195 and rs11168100 were associated with a decreased susceptibility to alcohol-induced ONFH in people ≤45 years. In addition, the necrotic sites stratification analysis showed that rs12654195 was only found to be related to alcohol-induced ONFH risk in the recessive model. In patients with different clinical stages, rs353300 was observed to be associated with a higher incidence of ONFH. Individuals with different genotypes of rs13177623, rs12654195 and rs11168100 had significantly different clinical parameters (cholinesterase, globulin, percentage of neutrophils and the absolute value of lymphocytes). CONCLUSIONS: Our data provided new light on the association between CARMEN polymorphisms and alcohol-induced ONFH risk in the Chinese Han population.

An innovative method to enhance protease tolerance of nisin in endogenous proteases.

Nisin, a natural peptide produced by Lactococcus lactis cultivation in milk whey, is widely used as a preservative in industrial production. However, nisin can be degraded by endogenous enzymes in foods. In this study, we investigated the antibacterial activity of nisin-soybean protein and nisin-egg white protein and compared them with that of free nisin in cantaloupe juice, which was used as a model of endogenous protease environment. Results showed that endogenous proteases in the model resulted in a loss of nisin activity, but combining nisin with protein (soybean or egg white) resulted in greater protection of its antimicrobial activity by inhibiting endogenous proteases. The microbial addition experiment (Staphylococcus aureus and Micrococcus luteus) and preservation experiment in the food model showed that the antibacterial activity of nisin combined with either of the 2 proteins was higher than that of nisin alone in an endogenous protease environment. In summary, soybean protein and egg white protein improved the protease tolerance of nisin, expanding the application scope of nisin in food.

Short communication: Global transcriptome analysis of Lactococcus lactis ssp. lactis in response to gradient freezing.

Lactic acid bacteria are often preserved as starter cultures by freezing to extend shelf stability as well as maintain cell viability and acidification activity. Previous studies showed that the endocyte extracted from gradient-freezing pretreated cells could act as lyoprotectant in the lyophilization process of Lactococcus lactis ssp. lactis. In this study, the molecular mechanisms of L. lactis in response to gradient freezing exposure are described using high-throughput sequencing. Nineteen of 56 genes were upregulated after gradient freezing, whereas 37 genes were downregulated. Further validation results of quantitative real-time PCR experiments were consistent with the RNA sequencing. Gene Ontology (http://www.geneontology.org/) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG; https://www.genome.jp/kegg/) pathway were used to analyze the differentially expressed genes. Several pathways, such as glutathione metabolism, ATP-binding cassette transport, metabolism of cell wall and cell membrane components, and stress response-related pathways, were affected by gradient freezing. Six genes relevant to freezing stress response were selected for quantitative real-time PCR, including 3 upregulated genes (hisK, eutD, dukA) and 3 downregulated genes (als, yedF, pepN). The Gene Ontology enrichment and KEGG pathway analyses showed these genes may influence stress response-related pathways, improving the survival of the L. lactis under freezing stress. The identification of these genes deepened an understanding about their response under freezing stress, helping us find potential genes or pathways related to gradient freezing for further research on lyoprotectants.

[Establishment of new evaluation standards for systemic anaphylactoid reactions using mouse model].

The detection of drug-induced anaphylactoid reactions remains a global challenge,still lacking mature and reliable animal models or test methods. Therefore,the purpose of this paper is to explore and establish the test methods and evaluation standards for anaphylactoid reactions that apply to injection drugs. Based on the anaphylactoid reaction symptoms of mice induced by intravenous injection drugs C48/40 and Tween 80,a list of systemic anaphylactoid reaction symptoms in mice was sorted out and an evaluation standard of anaphylactoid reactions symptoms was established by applying symptom intensity coefficient K( that can represent these verity of anaphylactoid reaction symptoms) and its calculation formula Accordingly,histamine,tryptase,and Ig E were selected as blood indicators of anaphylactoid reactions,so that a test method combining symptoms evaluation and blood makers detection was established.This test method could be used to evaluate the characteristics of anaphylactoid reactions: coefficient K,blood histamine levels were highly and positively correlated with C48/80 and Tween 80 dose; The log value of histamine was highly and positively correlated with K; tryptase level may rise,or remain steady,or drop,possibly associated with the characteristics of the tested object and time for blood taking; and Ig E level would drop or remain steady,but it would not rise,which can be clearly distinguished from type I allergic reactions. On this basis,tiohexol,iopromide,paclitaxel,Xuesaitong Injection,Shuanghuanglian Injection and Shengmai Injection were used to investigate the applicability. The testing results showed a high degree of consistency with the actual clinical situation. The results suggest that the method of systemic anaphylaxis test in mice has high sensitivity,specificity and good consistency with clinical practice.It is suggested to be further validated and popularized.

Protection of Spleen Tissue of γ-ray Irradiated Mice against Immunosuppressive and Oxidative Effects of Radiation by Adenosine 5'-Monophosphate.

The immune system is very sensitive to radiation. This study revealed that adenosine 5′-monophosphate (5′-AMP) increased the DNA contents of the spleen and the spleen index of irradiated mice. Moreover, the exogenous 5′-AMP could significantly repair the ultra-structure of the damaged spleen through transmission electron microscopy. When indicators of the mouse immune system were assessed, the flow cytometry and enzyme-linked immunosorbent assay (ELISA) revealed that the administration of exogenous 5′-AMP could reduce the apoptosis in the splenic cells. It could also regulate the transition of cells towards S phase, increase the proportion of CD4⁺ and CD8⁺ cellular subsets, and enhance the secretion of interleukin-2 (IL-2), IL-4, IL-10, and interferon-γ (IFN-γ). These effects were associated with a decrease in oxidative stress, as evidenced by changes in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), reduced glutathione (GSH), and malondialdehyde (MDA) levels of spleen tissues. These results suggested that exogenous 5′-AMP could repair the damaged spleen, increase the spleen index, and regulate the cell cycles and apoptosis. There was an increase in the production of various cytokines and play a protective role on the immune system of irradiated mice by dynamically adjusting the REDOX balance.

Protective Effects on 60Co-γ Radiation Damage of Pine Cone Polyphenols from Pinus koraiensis-Loaded Chitosan Microspheres In Vivo.

A novel chitosan microsphere for encapsulating pine cone polyphenols (PP) from P. koraiensis was successfully prepared using an emulsion crosslinking technique. The characteristics of pine polyphenol-loaded microspheres (PPM) were determined using scanning electron microscopy (SEM) and a laser particle size detector. It was found that PPMs were spherical in shape with uniform particle size distribution patterns. The drug content and encapsulation rate of the microspheres were 7.47% and 73.6%, respectively, at a Ch/GA mass ratio of 0.7. The animal experiments showed that PPM had a stronger radiation protective effect than PP. PPM significantly increased the immune organ indices, the quantity of marrow DNA, the superoxide dismutase (SOD) activity, the splenocyte proliferation index, and the phagocytosis activity of monocytes. PPM also decreased the numbers of micronuclei in bone marrow cells and malondialdehyde (MDA) levels in plasma in mice exposed to 60Co γ-irradiation. In addition, gender differences in biological responses to exposure to radiation were observed.

Biological characteristics and construction of stable ALDH-1 knock-down Hela cell lines.

OBJECTIVES: To explore the relationship between aldehye dehydrogenase-1 (ALDH-1) and biological characteristics of the stable ALDH-1 knock-down Hela cell lines. MATERIALS AND METHODS: Transfected Hela cells with lentiviral vector were utilized and puromycin was used to screen and achieve the stable cell lines. The interference efficiency was calculated by performing qRT-PCR to detect the expression of ALDH-1 of three groups including the interfering group, the negative control (NC) group, and the normal Hela group. CCK-8 assays were used to detect the OD value of each group. The coloning formation rate of each group was detected by colony formation assay. cell cycle distribution and apoptosis of each group were also detected by employing cell cycle and apoptosis experiments. Results: The stable ALDH-1 knock-down Hela cell lines were successfully obtained after two weeks' screening; compared with the NC and Hela group, the ALDH-1 expression level of interfering group was 1.05 ± 0.10 (both p < 0.05), whose silencing efficiency was 80.59%. CCK-8 assays verified that the mean OD value of interfering group was lower than that of NC and Hela group. Additionally, colony formation assays showed that the coloning efficiency of interfering group was lower than that of NC and Hela group. Cell cycle experiments proved that the proportion of G0/G1 phase of interfering group was higher than that of the other two groups, while the proportion of S phase was lower. Cell apoptosis assays indicated that the apoptosis rate of interfering group was the highest. CONCLUSIONS: Constructing stable interfering Hela cell lines with lentiviral vectors was successful and worthy of promotion. ALDH-1 plays an important role in promoting cell growth and proliferation, maintaining cell cycle and inhibiting Hela cell apoptosis.

Optimization of Purification, Identification and Evaluation of the in Vitro Antitumor Activity of Polyphenols from Pinus Koraiensis Pinecones.

In this study, an efficient purification method for the polyphenols of Pinus koraiensis pinecone (PPP) has been developed. AB-8 resin was verified to offer good adsorption and desorption ratio for PPP. Response surface methodology (RSM) indicated that the optimized purification parameters for PPP were 1.70 mg GAE/mL phenolic sample concentration, 22.00 mL sample volume, and 63.00% ethanol concentration. Under these conditions, the experimental purity of PPP was 27.93 ± 0.14% (n = 3), which matched well with the predicted purity of 28.17%. Next, the antiproliferative effects of PPP on seven cancer cell lines, including A375 (human skin melanoma cancer cell line), A549 (human lung cancer cell line), SH-SY5Y (human neuroblastoma cell line), LOVO (human colon cancer stem cell line), MCF-7 (human breast cancer cell line), HeLa (human cervical cancer line), and HT29 (human colon cancer line), were examined by MTT assays. The results indicated that PPP had the highest capacity for inhibiting LOVO cells growth with an EC50 value of 0.317 ± 0.0476 mg/mL. Finally, Ultra-high performance liquid chromatography- tandem mass spectrometry (UPLC-MS) was used to tentatively identify twenty-four peaks in the purified PPP, of which five representative peaks were identified as catechin, methyl quercetin, o-vanillin, luteolin and coronaric acid. Our results demonstrate that Pinus koraiensis pinecone is a readily available source of polyphenols, and the purified PPP could be a promising natural antitumor agent for applications in functional foods.

[Evaluation criteria for rat skin anaphylactoid test].

This study is to explore characteristic indexes in evaluation criteria for rat skin anaphylactoid test comparing skin blue spot OD values at the treated position and the control position in the same animal. Common contrast agents, traditional Chinese medicine injections and injections' active pharmaceutical ingredients or excipients in the existing clinical anaphylactoid reaction reports were taken as test drugs in the rat skin anaphylactoid test to define the K value: K > 2 represents positive anaphylactoid reaction, 1.2 ≤ K ≤ 2 represent doubtable anaphylactoid; K < 1.2 represents negative anaphylactoid reaction, which were taken as the criteria for evaluating anaphylactoid of tested drugs. The evaluation result and that for classic criteria were compared to study the applicability of K value. According to the comparison, K value, as the evaluation criteria in the rat skin anaphylactoid test, can more truly reflect the actual situation of skin aizen and minimize the error caused by animal individual factors. Compared with positive and negative two-level criteria for blue spot diameter, K value's positive, doubtable and negative three-level criteria are more objective and accurate. Therefore, K value can be used as the evaluation criteria in the rat skin anaphylactoid test.

Anti-fibrotic effects of Astragaloside IV in systemic sclerosis.

OBJECTIVE: To evaluate the anti-fibrotic effects of Astragaloside IV in systemic sclerosis. METHODS: Treated or untreated systemic sclerosis (SSc) and normal fibroblast isolated from corresponding pairs were utilized to detect expression of collagen and fibronectin by western blot, quantitative real-time RT-PCR (RT-qPCR), immunofluorescence staining and histopathological examination. SSc mouse model induced by bleomycin was used to evaluate the effects of the drug in vivo. RESULTS: Compared to normal fibroblast (NF), the expression of collagen and fibronectin in SSc (SScF) dramatically increased, and this could be reduced by Astragaloside IV (AST) in a dose- or time-dependent manner at both protein and mRNA levels. Administration of Astragaloside IV consistently decreased collagen formation and partially restored the structure, as well as suppressing collagen and fibronectin expression in the skin lesions of SSc-model mice. Mechanistically, Astragaloside IV-induced fibrosis reduction may be due to deregulation of Smad 3/Fli-1, the major mediators of the fibrotic response and key molecules for TGF-ß signaling. Astragaloside IV also decreased the level of p-SMAD3 and completely blocked its relocation into the nuclei. CONCLUSION: Astragaloside IV attenuates fibrosis by inhibiting the TGF-ß-Smads3 axis in systemic sclerosis.

Identification of a Novel Peptide with Alcohol Dehydrogenase Activating Ability from Ethanol-Induced Lactococcus lactis: A Combined In Silico Prediction and In Vivo Validation.

Alcohol dehydrogenase (ADH) is a crucial rate-limiting enzyme in alcohol metabolism. Our previous research found that ethanol-induced intracellular extracts of Lactococcus lactis (L. lactis) could enhance alcohol metabolism in mice, but the responsible compounds remain unidentified. The study aimed to screen potential ADH-activating peptides from ethanol-induced L. lactis using virtual screening and molecular docking calculation. Among them, the pentapeptide FAPEG might bind to ADH through hydrophobic interaction and hydrogen bonds, then enhancing ADH activity. Spectroscopy analysis further investigated the peptide-enzyme interaction between FAPEG and ADH, including changes in the amino acid residue microenvironment and secondary structural alterations. Furthermore, FAPEG could protect against alcoholic liver injury (ALI) in mice by reducing blood alcohol concentration, enhancing the activity of antioxidant and alcohol metabolism enzymes, and attenuating alcohol-induced hepatotoxicity, which was related to the activation of the Nrf2/keap1/HO-1 signaling pathway. The study provided preliminary evidence that the generation of ADH-activating peptides in ethanol-induced L. lactis has the potential in preventing ALI in mice using in silico prediction and in vivo validation approaches.

Biyang floral mushroom-derived exosome-like nanovesicles: characterization, absorption stability and ionizing radiation protection.

Diet-derived exosome-like nanovesicles are a class of natural active substances that have similar structures and functions to mammalian exosomes. Biyang floral mushrooms and their active extracts have been found to possess radioprotective effects and to deeply explore their novel active substances, the radioprotective effects of Biyang floral mushroom-derived exosome-like nanovesicles (BFMELNs) were investigated in this study. Results showed that these surface-negatively charged vesicles possessed an ideal size and good stability against environmental changes such as temperature and gastrointestinal digestion. Furthermore, BFMELNs could effectively be taken up by HL-7702 cells and Caco-2 cells through cellular phagocytosis mediated by clathrin and dynein. Emphatically, BFMELNs with an exosome-like morphology contained RNA, proteins, lipids, polyphenols and flavonoids to exert good antioxidant and radioprotective effects in vitro. Meanwhile, BFMELNs also exhibited good radioprotective effects by restoring peripheral blood indexes, mitigating damage to organs, and regulating the redox state in mice. Collectively, BFMELNs showed promise as novel and natural radioprotective nano-agents for preventing IR-induced oxidative stress damage.

Structural characterization of a glycoprotein from white jade snails (Achatina Fulica) and its wound healing activity.

Snail mucus is rich in proteins and polysaccharides, which has been proved to promote wound healing in mice in our previous research. The aim of this study was to investigate the effective component in snail mucus that can exert the wound healing potential and its structural characterization. Here, the glycoprotein from the snail mucus (SM1S) was obtained by DEAE-Sepharose Fast Flow and Sephacryl S-300 columns. The structural characteristics of SM1S were investigated via chromatographic techniques, periodic acid oxidation, FT-IR spectroscopy and NMR spectroscopy. Results showed that SM1S was a glycoprotein with a molecular weight of 3.8 kDa (83.23 %), consists of mannose, glucuronic acid, glucose, galactose, xylose, arabinose, fucose at a ratio of 13.180:4.875:1043.173:7.552:1:3.501:2.058. In addition, the periodic acid oxidation and NMR analysis showed that SM1S contained 1,6-glycosidic bonds, and might also contain 1 â†’ 4 and 1 â†’ 2 glycosidic or 1 â†’ 3 glycosidic bonds. Furthermore, the migration experiment of human skin fibroblasts in vitro suggested that SM1S had a good effect to accelerate the scratch healing of cells. This study suggested that SM1S may be a prospective candidate as a natural wound dressing for the development of snail mucus products.