Supplementation with compound polysaccharides contributes to the development and metabolic activity of young rat intestinal microbiota.

Dietary intervention during early life has a significant impact on colonization of the gut microbiota. In addition, some polysaccharides have the potential to selectively stimulate the growth and metabolic activity of intestinal bacteria associated with health and well-being. However, less is known about the effect of polysaccharides on the development of gut microbiota in younger individuals. This study was conducted to investigate the health effects of supplementation with dietary compound polysaccharides (Lycium barbarum polysaccharides (LBP), Poria cocos polysaccharides (PCPs) and Lentinan, 1 : 1 : 1) on the intestinal microecosystem and metabolism of young rats. Male 21-day-old Sprague-Dawley rats received daily intragastric administration of either compound polysaccharides (three dosages, 6 g kg-1, 12 g kg-1 or 24 g kg-1) or saline for 28 consecutive days. 1H-NMR spectroscopy integrated with multi-variate pattern recognition analysis was applied to reveal the metabolism of the host and microflora, while 16S rRNA gene sequencing was used to monitor the dynamic changes in the gut microbiota. The relative concentrations of 35 urinary metabolites and 24 faecal metabolites were significantly changed compared with the control group. 16S rRNA analysis showed that the relative abundances of 4 bacterial genera (Bifidobacterium, Lactobacillus, Allobaculum and Oligella) significantly increased, whereas the relative abundance of 1 bacterial genus (Enterococcus) significantly declined in the compound polysaccharide-treated groups compared with the control group. Meanwhile, dietary compound polysaccharide treatment promoted the functional maturation of the gut bacterial community, characterised by increased basic metabolism (amino acid metabolism and energy metabolism), short chain fatty acid (SCFA)-related metabolism and nucleotide metabolism. These findings suggest that compound polysaccharides may help to promote the colonisation and functional maturation of infant intestinal microbiota and maintain the health of the intestinal microecosystem.

The effect of probiotics and polysaccharides on the gut microbiota composition and function of weaned rats.

Weaning is an essential and important event for infants and rodent animals, and the dietary supplementation plays a crucial role in regulating the composition and function of gut microbiota in the initial period after weaning. In this study, we investigated the potential effects of two probiotics along with three polysaccharides (PP) in weaned rats. Male SD rats, 21 days of age, were divided into two groups: one group was administered with PP for four weeks and the other was not. Body weight, food intake, gut epithelial barrier function, digestive enzyme activities, and the composition and function of gut microbiota were analyzed. The dietary PP increased the body weight and food intake, promoted gut epithelial barrier integrity, and elevated the activities of digestive enzymes. Moreover, the microbial community structure was different between the two groups. At the genus level, Bifidobacterium, Lactobacillus, and Allobaculum were significantly increased, whereas Anaerostipes, Enterococcus, and Parabacteroides were observably reduced. Furthermore, PP significantly increased amino acid metabolism, energy metabolism, and SCFA-related metabolism. This study shows that synbiotics containing probiotics (L. acidophilus NCFM and B. lactis Bi-07) in combination with polysaccharides (LBP, PCPs, and Lentinan) can modulate the composition of gut microbiota, stimulate the maturation of gut microbiota biological function, and promote the growth performance in weaned rats.

Isolation and characterization of antiproliferative peptides from Chinese three-striped box turtle (Cuora trifasciata).

In this study, the whole proteins from a Chinese three-striped box turtle (Cuora trifasciata) were extracted and hydrolyzed using three proteases (alcalase, papain, and protamex). By orthogonal experiments, the optimal hydrolysis conditions for producing peptides with the highest cancer cells growth inhibition activity were determined. Such as, the maximum inhibition on MCF-7 cancer cells (92.37% at 1 mg/mL) was achieved by papain hydrolysis (pH 8, 37 °C, enzyme-to-substrate ratio (E/S) 1.5%), and the maximum inhibition on HepG2 cancer cells (94.16% at 1 mg/mL) was reached by protamex hydrolysis (pH 8, 40 °C, E/S 2%). Using ultrafiltration and Sephadex G-15 column chromatography, two polypeptides M2 and F4 were isolated. At 500 µg/mL, M2 exhibited 74.7% and 62.9% of antiproliferation activities on MCF-7 and HepG2 cancer cells, respectively; and F4 displayed good inhibitory effects on MCF-7 (70.59%) and HepG2 (78.6%) cancer cells. M2 and F4 had lower inhibition (<20%) than drug 5-FU (>60%) on normal liver cells L-O2. Moreover, three peptides, EMLQPPL, PGKPLFL, and SCCSCDED, were identified; their inhibitory effects on cancer cells were confirmed after synthesis. These data, for the first time, demonstrated that Cuora trifasciata-derived proteins could be used for preparing antiproliferation peptides.

Distinct urine metabolome after Asian ginseng and American ginseng intervention based on GC-MS metabolomics approach.

Ginseng occupies a prominent position in the list of best-selling natural products worldwide. Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius) show different properties and medicinal applications in pharmacology, even though the main active constituents of them are both thought to be ginsenosides. Metabolomics is a promising method to profile entire endogenous metabolites and monitor their fluctuations related to exogenous stimulus. Herein, an untargeted metabolomics approach was applied to study the overall urine metabolic differences between Asian ginseng and American ginseng in mice. Metabolomics analyses were performed using gas chromatography-mass spectrometry (GC-MS) together with multivariate statistical data analysis. A total of 21 metabolites related to D-glutamine and D-glutamate metabolism, glutathione metabolism, TCA cycle and glyoxylate and dicarboxylate metabolism, differed significantly under the Asian ginseng treatment; 34 metabolites mainly associated with glyoxylate and dicarboxylate metabolism, TCA cycle and taurine and hypotaurine metabolism, were significantly altered after American ginseng treatment. Urinary metabolomics reveal that Asian ginseng and American ginseng can benefit organism physiological and biological functions via regulating multiple metabolic pathways. The important pathways identified from Asian ginseng and American ginseng can also help to explore new therapeutic effects or action targets so as to broad application of these two ginsengs.

Separation and nanoencapsulation of antitumor peptides from Chinese three-striped box turtle (Cuora trifasciata).

Chinese three-striped box turtle (Cuora trifasciata), as a freshwater turtle, is used as a tonic food. The purpose of this study was to isolate peptides with cancer growth inhibition activity from trypsin-digested hydrolysates of turtle proteins. The results demonstrated that two fractions T1 and T2 exhibited good inhibition on HepG-2 and MCF-7 cancer cells, with an inhibition of 70.65-89.1%, at 500 µg/mL. Subsequently, three peptides were identified from T1 and T2, including RGVKGPR (T1-1), KLGPKGPR (T1-2), and SSPGPPVH (T2-1). By database search, T2-1 was a completely new peptide; its inhibition activity on MCF-7 cancer cells was the best, up to 70.02% at 500 µg/mL. Then, T1 and T2-1 were nanoencapsulated by chitosan. After nanoencapsulation, the inhibition percentages were 50.23% for the nanoencapsulated T1 on HepG-2 and 46.82% for the encapsulated T2-1 on MCF-7. The release experiment indicated that the encapsulated peptides could be slowly released in simulated gastrointestinal juice.

Purification, characterization, and biological activities of broccolini lectin.

Plant lectins have displayed a variety of biological activities. In this study, for the first time, a 27 kDa arabinose- and mannose-specific lectin from Broccolini (Brassica oleracea Italica × Alboglabra), named as BL (Broccolini lectin), was purified by an activity-driven protocol. Mass spectrometry analysis and database search indicated that no matches with any plant lectin were found, but BL contained some peptide fragments (QQQGQQGQQLQQVISR, QQGQQQGQQGQQLQQVISR and VCNIPQVSVCPF QK). BL exhibited hemagglutinating activity against chicken erythrocytes at 4 µg/mL. BL retained full hemagglutinating activity at pH 7-8 and temperature 30-40°C, and had an optimal activity in Ca(2+) solution. Bioactivity assay revealed that BL exhibited dose-dependent inhibition activity on 5 bacterial species with IC50 values of 143.95-486.33 µg/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 µg/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 µg/mL). This suggests that BL should be promising in food and medicine.

The in vivo and in vitro study of polysaccharides from a two-herb formula on ulcerative colitis and potential mechanism of action.

ETHNOPHARMACOLOGICAL RELEVANCE: Lycium barbarum and Astragalus membranaceus are two traditional medicinal herbs widely used in China for nourishing Yin and reinforcing Qi. The purpose of the study was to investigate the prophylactic and curative effects of crude polysaccharides (QHPS) extracted from a two-herb formula composed of Lycium barbarum and Astragalus membranaceus at a ratio of 2:3 in colitis rats, and to further elucidate the potential mechanism of action in epithelial cell proliferation in vitro. MATERIALS AND METHODS: An acetic acid (AA)-induced ulcerative colitis rat model was applied in the study. Two independent protocols were used to assess the prophylactic and curative effects of QHPS, respectively, in which rats were either pre-treated with QHPS (0.18g/kg) for 14 days prior to AA induction, or post-treated with QHPS for 7 days after AA induction. The stool consistency and weight loss were used to evaluate disease activity. The morphological changes in intestinal mucosa at the end of the experiments were observed. The serum levels of endotoxin (EDT), diamine oxidase (DAO) and d-lactate (DLA), important biochemical markers for evaluating intestinal mucosal structure and function, were measured. In the in vitro mechanistic studies, rat intestinal epithelial cells (IEC-6) were used to access for epithelium regeneration. RESULTS: The intra-colonic instillation of AA induced ulcerative colitis in rat, as indicated by diarrhea, weight loss, and colonic mucosal damage. Both prophylactic and curative treatments effectively reduced the weight loss and diarrhea and attenuated the colonic mucosal damage associated with inducible colitis. The significant increase in serum levels of DAO, DLA and EDT was induced by AA and inhibited by QHPS treatment. Moreover, QHPS could significantly stimulate IEC-6 proliferation in a dose-dependent manner (p<0.05). CONCLUSION: The present study indicated for the first time that polysaccharides extracted from this two-herb formula can protect against experimental ulcerative colitis, presumably by promoting the recovery of the intestinal barrier.

Metabolic Signatures of Kidney Yang Deficiency Syndrome and Protective Effects of Two Herbal Extracts in Rats Using GC/TOF MS.

Kidney Yang Deficiency Syndrome (KDS-Yang), a typical condition in Chinese medicine, shares similar clinical signs of the glucocorticoid withdrawal syndrome. To date, the underlying mechanism of KDS-Yang has been remained unclear, especially at the metabolic level. In this study, we report a metabolomic profiling study on a classical model of KDS-Yang in rats induced by hydrocortisone injection to characterize the metabolic transformation using gas chromatography/time-of-flight mass spectrometry. WKY1, a polysaccharide extract from Astragalus membranaceus and Lycium barbarum, and WKY2, an aqueous extract from a similar formula containing Astragalus membranaceus, Lycium barbarum, Morinda officinalis, Taraxacum mongolicum, and Cinnamomum cassia presl, were used separately for protective treatments of KDS-Yang. The changes of serum metabolic profiles indicated that significant alterations of key metabolic pathways in response to abrupt hydrocortisone perturbation, including decreased energy metabolism (lactic acid, acetylcarnitine), lipid metabolism (free fatty acids, 1-monolinoleoylglycerol, and cholesterol), gut microbiota metabolism (indole-3-propionic acid), biosynthesis of catecholamine (norepinephrine), and elevated alanine metabolism, were attenuated or normalized with different degrees by the pretreatment of WKY1 or WKY2, which is consistent with the observations in which the two herbal agents could ameliorate biochemical markers of serum cortisone, adrenocorticotropic (ACTH), and urine 17-hydroxycorticosteroids (17-OHCS).

Gut microbiota, host health, and polysaccharides.

The intestinal microbiota is a complicated ecosystem that influences many aspects of host physiology (i.e. diet, disease development, drug metabolism, and regulation of the immune system). It also exhibits spatial patterning and temporal dynamics. In this review, the effects of internal and external (environmental) factors on intestinal microbiota are discussed. We describe the roles of the gut microbiota in maintaining intestinal and immune system homeostasis and the relationship between gut microbiota and diseases. In particular, the contributions of polysaccharides, as the most abundant diet components in intestinal microbiota and host health are presented. Finally, perspectives for research avenues relating to gut microbiota are also discussed.

Polysaccharide from Lentinus edodes inhibits the immunosuppressive function of myeloid-derived suppressor cells.

Reversing the function of immune suppressor cells may improve the efficacy of cancer therapy. Here, we have isolated a novel polysaccharide MPSSS (577.2 Kd) from Lentinus edodes and examined its effects on differentiation and function of myeloid-derived suppressor cells (MDSCs). MPSSS is composed of glucose (75.0%), galactose (11.7%), mannose (7.8%), and xylose (0.4%). In vivo, it inhibits the growth of McgR32 tumor cells, which is correlated with a reduced percentage of MDSCs in peripheral blood. In vitro, it induces both morphological and biophysical changes in MDSCs. Importantly, MPSSS up-regulates MHC II and F4/80 expression on MDSCs, and reverses their inhibition effect on CD4(+) T cells in a dose-dependent manner. The mechanism study shows that MPSSS may stimulate MDSCs through a MyD88 dependent NF-κB signaling pathway. Together, we demonstrated for the first time that MPSSS stimulates the differentiation of MDSCs and reverses its immunosuppressive functions, shedding new light on developing novel anti-cancer strategies by targeting MDSCs.

A homogalacturonan from the radix of Platycodon grandiflorum and the anti-angiogenesis activity of poly-/oligogalacturonic acids derived therefrom.

A polysaccharide, PGA4-3b, with an average molecular weight of 8.9kDa estimated by high-performance gel-permeation chromatography (HPGPC), was isolated from radix of Platycodon grandiflorum (Jacq.) A. DC. Using monosaccharide analysis, methylation analysis and NMR spectroscopy, PGA4-3b was elucidated to be a linear poly-(1→4)-α-d-galactopyranosyluronic acid that contains no methyl ester groups. Partial acid hydrolysis of PGA4-3b yielded a series of poly- or oligogalacturonic acids with different degrees of polymerization (DP), that is, 4-3bde, 4-3bde-O-1, 4-3bde-O-2, 4-3bde-O-3, and 4-3bde-O-4. Cell tube formation inhibition tests with human microvascular endothelial cells (HMEC) for antiangiogenesis analysis showed that 4-3bde-O-1 and 4-3bde-O-2, the fractions with higher molecular weights, could inhibit tube formation, while the native PGA4-3b and low molecular weight fraction 4-3bde-O-3 and 4-3bde-O4 are ineffective. Moreover, 4-3bde-O-2 with DP 5-10 impaired cell tube formation in a dose-dependent way, suggesting its potential to be developed as an anti-angiogenesis drug. This is the first time oligogalacturonic acids are reported to show an anti-angiogenesis effect.