Structural characterization of corn silk polysaccharides and its effect in H2O2 induced oxidative damage in L6 skeletal muscle cells

Extraction, purification, structural characteristics, and pharmacological activities of the polysaccharides from corn silk: A review

Corn silk is widely used as a traditional Chinese medicine possessing multiple beneficial effects, whose active ingredient is corn silk polysaccharide (CSP). CSP is abundant in corn silk, and has a variety of bioactivities, such as antioxidant, hypoglycemic, hypolipidemic, hepatorenal-protective, antitumor, anti-fatigue, immunomodulating, and anti-ischemia-reperfusion injury effects. Moreover, CSP ameliorates diabetes, diabetes nephropathy, and hyperlipidemia. This review aimed to comprehensively and systematically summarize recent information on the extraction, purification, structural characterization, biological activity, potential mechanism, and toxicity of CSP. Thus, it could provide a reference for the further use of CSP and discuss the future prospects of CSP research and development.

Physical properties, phenolic profile and antioxidant capacity of Java tea (Clerodendranthus spicatus) stems as affected by steam explosion treatment

Java tea (Clerodendranthus spicatus) has been favored for its various health benefits and abundance of phenolic substances. Steam explosion (SE) treatment was performed in the pretreatment of Java tea stems and the physical properties, phenolic profile and antioxidant capacity were investigated. Extraction kinetics study showed that the phenolics yields of Java tea stems treated at 2.4 MPa for 10 min reached the maximum in 40 min, which was approximately 3 times the yields of raw stems in 180 min. The antioxidant activities of the extracts of Java tea stems were also significantly increased after SE treatment (P < 0.05). In addition, 19 phenolics were detected in Java tea stems by HPLC/QTOF-MS/MS, and rosmarinic acid was found to be hydrolyzed to danshensu during the SE process. SE could be an efficient pretreatment technology to improve the extraction rates of phenolics and conversions of their high-value hydrolyzed products, which could facilitate further research of Java tea products.

Corn Silk Polysaccharide Reduces the Risk of Kidney Stone Formation by Reducing Oxidative Stress and Inhibiting COM Crystal Adhesion and Aggregation

The aim of this study is to explore the inhibition of nanocalcium oxalate monohydrate (nano-COM) crystal adhesion and aggregation on the HK-2 cell surface after the protection of corn silk polysaccharides (CSPs) and the effect of carboxyl group (-COOH) content and polysaccharide concentration.

METHOD

HK-2 cells were damaged by 100 nm COM crystals to build an injury model. The cells were protected by CSPs with -COOH contents of 3.92% (CSP0) and 16.38% (CCSP3), respectively. The changes in the biochemical indexes of HK-2 cells and the difference in adhesion amount and aggregation degree of nano-COM on the cell surface before and after CSP protection were detected.

RESULTS

CSP0 and CCSP3 protection can obviously inhibit HK-2 cell damage caused by nano-COM crystals, restore cytoskeleton morphology, reduce intracellular ROS level, inhibit phosphoserine eversion, restore the polarity of the mitochondrial membrane potential, normalize the cell cycle process, and reduce the expression of adhesion molecules, OPN, Annexin A1, HSP90, HAS3, and CD44 on the cell surface. Finally, the adhesion and aggregation of nano-COM crystals on the cell surface were effectively inhibited. The carboxymethylated CSP3 exhibited a higher protective effect on cells than the original CSP0, and cell viability was further improved with the increase in polysaccharide concentration.

CONCLUSIONS

CSPs can protect HK-2 cells from calcium oxalate crystal damage and effectively reduce the adhesion and aggregation of nano-COM crystals on the cell surface, which is conducive to inhibiting the formation of calcium oxalate kidney stones.

An in-depth investigation of molecular interaction in zeaxanthin/corn silk glycan complexes and its positive role in hypoglycemic activity

Glycans in corn silk could interact with co-existing small molecules during its absorption, digestion, and biological process. In order to understand the exact mechanism of action of zeaxanthin, it is critical to investigate the biomolecular interactions, which were necessary to form a glycan-small molecule complex and yet produce the bioactive effect. So far, the in-depth study of these natural interactions has not been fully elucidated. Here, we probed that the molecular interaction between zeaxanthin (ZEA) and glycans from corn silk (CSGs) was driven by enthalpy. More importantly, it was the first time found that CSGs can bind to lipid-soluble ZEA could be binded with CSGs. It was the first report on the thermostability of insulin structure and natural glycans. This study should facilitate our understanding of the interaction between lipid soluble molecules and glycans, and provide a more comprehensive understanding of the nutrient base in food.

Lichen pectin-containing polysaccharide from Xanthoria elegans and its ability to effectively protect LX-2 cells from H2O2-induced oxidative damage

Xanthoria elegans, a drought-tolerant lichen, is the original plant of the traditional Chinese medicine "Shihua" and effectively treats a variety of liver diseases. However, thus far, the hepatoprotective effects of polysaccharides, the most important chemical constituents of X. elegans, have not been determined. The aim of this study was to screen the polysaccharide fraction for hepatoprotective activity by using free radical scavenging assays and a H2O2-induced Lieming Xu-2 cell (LX-2) oxidative damage model and to elucidate the chemical composition of the bioactive polysaccharide fraction. In the present study, three polysaccharide fractions (XEP-50, XEP-70 and XEP-90) were obtained from X. elegans by hot-water extraction, DEAE-cellulose anion exchange chromatography separation and ethanol gradient precipitation. Among the three polysaccharide fractions, XEP-70 exhibited the best antioxidant activity in free radical scavenging capacity and reducing power assays. Structural studies showed that XEP-70 was a pectin-containing heteropolysaccharide fraction that was composed mainly of (1 → 4)-linked and (1 → 4,6)-linked α-D-Glcp, (1 → 4)-linked α-D-GalpA, (1 → 2)-linked, (1 → 6)-linked and (1 → 2,6)-linked α-D-Manp, and (1 → 6)-linked and (1 → 2,6)-linked β-D-Galf. Furthermore, XEP-70 exhibited effectively protect LX-2 cells against H2O2-induced oxidative damage by enhancing cellular antioxidant capacity by activating the Nrf2/Keap1/ARE signaling pathway. Thus, XEP-70 has good potential to protect hepatic stellate cells against oxidative damage.

Cnidium officinale polysaccharide enhanced RAW 264.7 cells activation and NK-92 cells cytotoxicity against colon cancer via NF-κB and MAPKs signaling pathways

In this study, Cnidium officinale-derived polysaccharides were isolated and investigated for their immune enhancing and anticancer activities. The isolated crude and its fractions, such as F1 and F2, contain carbohydrates (51.3-63.1%), sulfates (5.4-5.8%), proteins (1.5-7.1%), and uronic acids (2.1-26.9%). The molecular weight (Mw) of the polysaccharides ranged from 59.9 to 429.0 × 103 g/mol. The immunostimulatory activity of the polysaccharides was tested on RAW 264.7 cells, and the results showed that the F2 treatment notably enhanced pro-inflammatory activity in RAW 264.7 cells by increasing NO production and the expression of various cytokines. Furthermore, the influence of polysaccharide treatment on natural killer cells (NK-92) anticancer activities was investigated using a colon cancer cell line (HCT-116). Crude polysaccharide and its fractions showed no direct cytotoxicity to NK-92 and HCT-116 cells. However, the treatment of F2 showed an enhancement of NK-92 cells cytotoxicity against HCT-116 cells by upregulating the mRNA expression of IFN-γ, TNF-α, NKGp44, and granzyme-B. The western blot results showed that the induced RAW 264.7 cells activation and NK-92 cells cytotoxicity occur via NF-κB and MAPK signaling pathways. Overall, C. officinale-derived polysaccharides show potential as immunotherapeutic agents capable of enhancing pro-inflammatory macrophage signaling and activating NK-92 cells; thus, they could be useful for biomedical applications.

Dietary Polysaccharides Exert Anti-Fatigue Functions via the Gut-Muscle Axis: Advances and Prospectives

Due to today's fast-paced lifestyle, most people are in a state of sub-health and face "unexplained fatigue", which can seriously affect their health, work efficiency, and quality of life. Fatigue is also a common symptom of several serious diseases such as Parkinson's, Alzheimer's, cancer, etc. However, the contributing mechanisms are not clear, and there are currently no official recommendations for the treatment of fatigue. Some dietary polysaccharides are often used as health care supplements; these have been reported to have specific anti-fatigue effects, with minor side effects and rich pharmacological activities. Dietary polysaccharides can be activated during food processing or during gastrointestinal transit, exerting unique effects. This review aims to comprehensively summarize and evaluate the latest advances in the biological processes of exercise-induced fatigue, to understand dietary polysaccharides and their possible molecular mechanisms in alleviating exercise-induced fatigue, and to systematically elaborate the roles of gut microbiota and the gut-muscle axis in this process. From the perspective of the gut-muscle axis, investigating the relationship between polysaccharides and fatigue will enhance our understanding of fatigue and may lead to a significant breakthrough regarding the molecular mechanism of fatigue. This paper will provide new perspectives for further research into the use of polysaccharides in food science and food nutrition, which could help develop potential anti-fatigue agents and open up novel therapies for sub-health conditions.

Structural Characterization and Anti-inflammatory Activities of Anticomplementary Polysaccharides from Rhododendron principis

Rhododendron principis leaves have been used as "Dama", a Traditional Tibetan Medicine for treating inflammatory diseases. R. principis crude polysaccharides with anticomplementary activity demonstrated promising anti-inflammatory effects on acute lung injury induced by lipopolysaccharide. R. principis crude polysaccharides significantly decreased the levels of TNF-α and interleukin-6 in both serum and blood and bronchoalveolar lavage fluid in lipopolysaccharide-induced acute lung injury mice by intragastric administration (100 mg/kg). A heteropolysaccharide, ZNDHP, was obtained from R. principis crude polysaccharides with successive anticomplementary activity-guided separation. ZNDHP was characterized as a branched neutral polysaccharide with a backbone composed of → 2)-β-Glcp-(1→, → 2,6)-α-Glcp-(1→, → 6,3)-β-Galp-(1→, → 2,6)-α-Galp-(1→, → 6,2)-β-Glcp-(1→, → 4)-α-Glcp-(1→, → 5)-β-Araf-(1→, → 3,5)-α-Araf-(1→, and → 4,6)-β-Manp-(1→, and the backbone structure was further confirmed by partial acid hydrolysis. In addition to anticomplementary and antioxidant activities, ZNDHP exhibited potent anti-inflammatory activity by significantly inhibiting the secretion of nitric oxide, TNF-α, interleukin-6, and interleukin-1β of lipopolysaccharide-treated RAW 264.7 cells. However, all of these activities decreased greatly after partially hydrolyzing, indicating the importance of the multibranched structure for its bioactivity. Therefore, ZNDHP might be an important component of R. principis for treating inflammation.

Ultrasound-assisted extraction and characteristics of maize polysaccharides from different sites

Antitumor, antioxidant, hypoglycemic, and immunomodulatory properties are all exhibited by maize polysaccharides. With the increasing sophistication of maize polysaccharide extraction methods, enzymatic method is no longer limited to a single enzyme to extract polysaccharides, and is more often used in combination with ultrasound or microwave, or combination with different enzymes. Ultrasound has a good cell wall-breaking effect, making it easier to dislodge lignin and hemicellulose from the cellulose surface of the maize husk. The "water extraction and alcohol precipitation" method is the simplest but most resource- and time-consuming process. However, the "ultrasound-assisted extraction" and "microwave-assisted extraction" methods not only compensate for the shortcoming, but also increase the extraction rate. Herein, the preparation, structural analysis, and activities of maize polysaccharides were analyzed and discussed.

Acidic polysaccharide from corn silk: Structural & conformational properties and hepatoprotective activity

This study aimed to investigate the structural characterization, conformational properties, and hepatoprotective activity of corn silk acidic polysaccharide (CSP-50E). CSP-50E with molecular weights of 1.93 × 10⁵ g/mol was composed of Gal, Glc, Rha, Ara, Xyl, Man and uronic acid with a weight ratio of 12:25:1:2:2:5:21. Structural analysis with methylation indicated that CSP-50E mainly contained T-Manp, 4-substituted-_D-Galp/GalpA, and 4-substituted-_D-Glcp. CSP-50E presented random coils conformation in an aqueous solution based on the analysis of HPSEC. In vitro experiments showed that CSP-50E exhibited significant hepatoprotective effects, CSP-50E reduce IL-6, TNF-α content, and AST, ALT activity to protect ethanol-induced damage liver cells (HL-7702), while the polysaccharide functioned mainly through the caspase cascade and mediate the mitochondrial apoptosis pathway. In this study, we describe a novel acidic polysaccharide from corn silk with hepatoprotective activity that facilitates the development and utilization of corn silk resources.

Carboxymethylation of Desmodium styracifolium Polysaccharide and Its Repair Effect on Damaged HK-2 Cells

Objective

Desmodium styracifolium is the best traditional medicine for treating kidney calculi in China. This study is aimed at increasing the carboxyl (-COOH) content of D. styracifolium polysaccharide (DSP0) and further increasing its antistone activity.

Methods

DSP0 was carboxymethylated with chloroacetic acid at varying degrees. Then, oxalate-damaged HK-2 cells were repaired with modified polysaccharide, and the changes in biochemical indices before and after repair were detected.

Results

Three modified polysaccharides with 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3) -COOH are obtained. Compared with DSP0 (-COOH content = 1.17%), CDSPs have stronger antioxidant activity in vitro and can improve the vitality of damaged HK-2 cells. CDSPs repair the cell morphology and cytoskeleton, increase the cell healing ability, reduce reactive oxygen species and nitric oxide levels, increase mitochondrial membrane potential, limit autophagy level to a low level, reduce the eversion of phosphatidylserine in the cell membrane, weaken the inhibition of oxalate on DNA synthesis, restore cell cycle to normal state, promote cell proliferation, and reduce apoptosis/necrosis.

Conclusion

The carboxymethylation modification of DSP0 can improve its antioxidant activity and enhance its ability to repair damaged HK-2 cells. Among them, CDSP2 with medium -COOH content has the highest activity of repairing cells, whereas CDSP3 with the highest -COOH content has the highest antioxidant activity. This difference may be related to the active environment of polysaccharide and conformation of the polysaccharide and cell signal pathway. This result suggests that Desmodium styracifolium polysaccharide with increased -COOH content may have improved potential treatment and prevention of kidney calculi.

Hemicellulosic Polysaccharides From Bamboo Leaves Promoted by Phosphotungstic Acids and Its Attenuation of Oxidative Stress in HepG2 Cells

In this work, we exploited an efficient method to release hemicellulosic polysaccharides (BLHP) from bamboo (Phyllostachys pubescens Mazel) leaves assisted by a small amount of phosphotungstic acid. Structural unit analysis proved that BLHP-A1 and BLHP-B1 samples possessed abundant low-branch chains in →4)-β-_D-Xylp-(1→ skeleton mainly consisting of Xylp, Manp, Glcp, Galp, and Araf residues. According to the results of the antioxidant activity assays in vitro, both of the two fractions demonstrated the activity for scavenging DPPH⋅ and ABTS⁺ radicals and exhibited relatively a high reducing ability compared to the recently reported polysaccharides. Moreover, the antioxidant activities of purified polysaccharides were evaluated against H₂O₂-induced oxidative stress damage in HepG2 cells. BLHP-B1 showed more activity for preventing damages from H₂O₂ in HepG2 cells by improving the enzyme activities of SOD, CAT, and GSH-Px and decreasing the production of MDA as well as suppressing reactive oxygen species (ROS) formation. This study implied that BLHP could demonstrate its attenuation ability for oxidative stress in HepG2 cells.

Structural characterization, antioxidant, and anti-inflammatory activity of polysaccharides from Plumula Nelumbinis

A polysaccharide from Plumula Nelumbinis (PNP), was isolated and purified. PNP had a molecular weight of 450 kDa and consisted five monosaccharides, including rhamnose, galacturonic acid, xylose, galactose, and arabinose. The methylation and nuclear magnetic resonance (NMR) analysis revealed that the main glycosidic linkage types of PNP were →5)-α-L-Araf-(1→, →3)-β-D-Galp-(1→, β-D-Xylp-(→1, →3,4)-β-D-Rhap-(1→, →4)-β-D-GalpA-(1→. In the range of 25-1200 μg/mL, PNP had no cytotoxicity to RAW264.7 cells. PNP could protect RAW264.7 cell from oxidative damage by reducing the production of ROS and MDA and the secretion of LDH, enhancing the activity of SOD, CAT, and GSH-Px, and increasing the content of GSH. Anti-inflammatory activity experiments showed that PNP inhibited the expression of NO, TNF-α, INF-γ, IL-1β, and IL-6. PNP could inhibit the activation of MAPK/NF-κB cell pathways. PNP could be used as a potential natural antioxidant and anti-inflammatory substance in functional foods and pharmaceuticals.

Purification, structural characterization and neuroprotective effect of a neutral polysaccharide from Sparassis crispa

In the present study, a purified polysaccharide (named SCP-1, Mw 1.368 × 10⁴ Da) was isolated from Sparassis crispa, and its biological activity was evaluated in an oxidative stress model caused by H₂O₂ in hippocampal neuronal HT22 cells. SCP-1 was a heteropolysaccharide mainly comprising glucose, galactose, fucose, and mannose in a molar ratio of 52.10: 31.10: 15.04: 1.76. The main backbone of SCP-1 was predominantly composed of (1→6)-α-_D-Galp, (1→6)-β-_D-Glcp, (1→3)-β-_D-Glcp, (1→2,6)-α-_D-Galp and (1→3,6)-β-_D-Glcp. The branches, substituted at the O-2 of Gal and O-3 of Glc, contained (1→6)-2-OMe-α-_D-Galp, (1→4)-β-_D-Glcp, (1→3)-β-_D-Glcp, and terminated by T-α-_L-Fucp and T-β-_D-Glcp. Besides, SCP-1 could effectively protect the HT22 cells against H₂O₂-induced oxidative injury via decreasing the intracellular reactive oxygen species levels, modulating antioxidant enzymes, and reducing cell apoptosis. The findings suggested that SCP-1 holds a potential to be a natural antioxidant or as a neuroprotective agent.

Bovine lactoferrin and Lentinus edodes mycelia polysaccharide complex: The formation and the activity to protect islet β cells

The formation of complexes may be used for the development of delivery systems in foods field. The aim of this study was to explore the interaction mechanism between Lentinus edodes mycelia polysaccharide (LMP) and bovine lactoferrin (BLF), and the activity of LMP-BLF complex to inhibit oxidative stress in islet β cells. The interaction mechanisms of LMP with BLF were investigated with multi-spectroscopic techniques. The multi-spectroscopic analysis result showed that LMP bound with BLF by van der Waals force and hydrogen bond. The quenching mechanism of BLF with LMP was static quenching. Cell viability, reactive oxygen species (ROS) level, apoptosis and the related signaling pathways were detected with thiazolyl blue tetrazolium bromide (MTT) assay, 2,7-Dichlorofluorescin diacetate (DCFH-DA) staining, Hoechst 33258 staining and Western blot methods respectively. The complex alleviated apoptosis induced by hydrogen peroxide (H₂O₂), and inhibited oxidative stress via MAPK pathways in MIN6 cells. In addition, the complex was able to promote glucose uptake in HepG2 cells. These results will broaden our understanding of LMP-BLF complexes and the applications of polysaccharide-protein complexes in the foods field.

Effect of extraction method on the chemical profiles and bioactivities of soybean hull polysaccharides

The yields, properties, and bioactivities of polysaccharides extracted by three methods from soybean hulls (SSCPs) were evaluated: hot water extraction (H-SSCP), microwave-assisted ammonium oxalate extraction (A-SSCP), and microwave-assisted sodium citrate extraction (S-SSCP). A-SSCP gave the highest yield of polysaccharides (9.3 ± 0.5%) although all three products had similar physicochemical characteristics and FT-IR spectra. A-SSCP and S-SSCP produced polysaccharides with lower molecular weight distributions and higher total reducing power and scavenging ability for ABTS+• and DPPH• free radicals. Furthermore, the effect of SSCPs on carbon tetrachloride (CCl4)-induced liver injury was investigated in the mice. When compared with H-SSCP and S-SSCP, A-SSCP significantly decreased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), and reactive oxygen (ROS) to normal (p < .05) and increased the level of glutathione (GSH) to normal (p < .05). A-SSCP was the most effective polysaccharide, yielding an approximately normal hepatic appearance with well-preserved cytoplasm, obvious cell boundaries, with legible nuclei and nucleoli. This study indicates that polysaccharides extracted from soybean hulls via microwave-assisted ammonium oxalate extraction have the potential to be developed as a new functional food contributing to the alleviation of liver damage.

Effect of Fe (III), Zn (II), and Cr (III) complexation on the physicochemical properties and bioactivities of corn silk polysaccharide

In this paper, Fe (III), Zn (II), and Cr (III) were used to complex with corn silk polysaccharide (CSP) by classical methods and CSP-Fe, CSP-Zn, and CSP-Cr were successfully synthesized, respectively. The physicochemical properties and structural features were characterized by chemical composition analysis, inductive coupled plasma-mass spectrometry (ICP-MS), ultraviolet-visible (UV-Vis) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC), respectively. The antioxidant activities and inhibitory effects on α-glucosidase of CSP, CSP-Fe, CSP-Zn, and CSP-Cr were compared. The results showed that the Fe (III), Zn (II), and Cr (III) chelation could change the morphology, conformation, thermostability, and biological activities of CSP. CSP-Zn exhibited higher antioxidant activities and inhibition effects on α-glucosidase than CSP, which suggested that it could be considered as a potential candidate for developing an ingredient of functional foods for antidiabetics.

Ameliorated membranous nephropathy activities of two ethanol extracts from corn silk and identification of flavonoid active compounds by LC-MS2

The current study looks to evaluate the effect of corn silk flavonoids on membranous nephropathy (MN). Polyamide resin (PR) can be used to enrich corn silk ethanol extract (CSEE) to obtain flavonoid-rich extract (PR-CSEE), the total flavonoid content (TFC) of which we found to be 57.4%. The results of scanning electron microscope, Fourier-transform infrared, and high-performance liquid chromatography analyses determined that PR-CSEE and CSEE have different structural characteristics, but that PR-CSEE has higher TFC. MN mice models were induced by cationic bovine serum albumin, and we found that PR-CSEE administration reduced urine protein levels markedly, while renal function, glomerular atrophy, inflammatory infiltration, and in-serum immunoglobulin G and complement 3 content were improved. Through LC-MS² spectrometry analysis, we pinpointed the 12 major flavonoid active compounds in PR-CSEE. These findings suggest that PR-CSEE can act as a potential functional food material by which to improve MN.

An Overview of Physical Exercise and Antioxidant Supplementation Influences on Skeletal Muscle Oxidative Stress

One of the essential injuries caused by moderate to high-intensity and short-duration physical activities is the overproduction of reactive oxygen species (ROS), damaging various body tissues such as skeletal muscle (SM). However, ROS is easily controlled by antioxidant defense systems during low to moderate intensity and long-term exercises. In stressful situations, antioxidant supplements are recommended to prevent ROS damage. We examined the response of SM to ROS generation during exercise using an antioxidant supplement treatment strategy in this study. The findings of this review research are paradoxical due to variances in antioxidant supplements dose and duration, intensity, length, frequency, types of exercise activities, and, in general, the lack of a regular exercise and nutrition strategy. As such, further research in this area is still being felt.

In Vitro Effects of Emerging Bisphenols on Myocyte Differentiation and Insulin Responsiveness

Bisphenols are endocrine disrupting chemicals to which humans are ubiquitously exposed to. Prenatal bisphenol A exposure can lead to insulin resistance. However, the metabolic effects of other emerging bisphenols, such as bisphenol S (BPS) and bisphenol F (BPF), are less understood. Because the skeletal muscle is the largest of the insulin target tissues, the goal of this study was to evaluate the effects of 2 emerging bisphenols (BPS and BPF) on cytotoxicity, proliferation, myogenic differentiation, and insulin responsiveness in skeletal muscle cells. We tested this using a dose-response approach in C2C12 mouse and L6 rat myoblast cell lines. The results showed that C2C12 mouse myoblasts were more susceptible to bisphenols compared with L6 rat myoblasts. In both cell lines, bisphenol A was more cytotoxic, followed by BPF and BPS. C2C12 myoblast proliferation was higher upon BPF exposure at the 10-4 M dose and the fusion index was increased after exposure to either BPF or BPS at doses over 10-10 M. Exposure to BPS and BPF also reduced baseline expression of p-AKT (Thr) and p-GSK-3β, but not downstream effectors such as mTOR and glucose transporter-4. In conclusion, at noncytotoxic doses, BPS and BPF can alter myoblast cell proliferation, differentiation, and partially modulate early effectors of the insulin receptor signaling pathway. However, BPS or BPF short-term exposure evaluated here does not result in impaired insulin responsiveness.

Carboxymethylation of Corn Silk Polysaccharide and Its Inhibition on Adhesion of Nanocalcium Oxalate Crystals to Damaged Renal Epithelial Cells

The purpose of this study was to explore the repair effect of carboxymethyl-modified corn silk polysaccharide (CSP) on oxidatively damaged renal epithelial cells and the difference in adhesion between cells and calcium oxalate crystals. The CSP was degraded and modified through carboxymethylation. An oxidatively damaged cell model was constructed by oxalate damage to human kidney proximal tubular epithelial (HK-2) cells. Then, the damaged cells were repaired by modified polysaccharides, and the changes in biochemical indexes and adhesion ability between cells and crystals before and after repair were detected. Four modified polysaccharides with carboxyl group (-COOH) contents of 3.92% (CSP0), 7.75% (CCSP1), 12.90% (CCSP2), and 16.38% (CCSP3) were obtained. Compared with CSP0, CCSPs had stronger antioxidant activity, could repair damaged HK-2 cells, and could reduce phosphorylated serine eversion on the cell membrane, the expression of osteopontin (OPN) and Annexin A1, and crystal adhesion. However, its effect on the expression of hyaluronic acid synthase was not substantial. The carboxymethyl modification of the CSP can improve its ability to repair cells and inhibit crystal adhesion and aggregation. A high carboxymethylation degree results in strong polysaccharide activity. CCSPs are expected to reduce the risk of kidney stone formation and recurrence.

The structural characteristic of acidic-hydrolyzed corn silk polysaccharides and its protection on the H2O2-injured intestinal epithelial cells

This work aims to describe the purification and characterization of acidic-hydrolyzed corn silk polysaccharides (AH-CSP) and evaluate their protection on the H₂O₂-injured intestinalepithelial cells (IEC-6). Two fractions named AHP-1 and AHP-2 were obtained from AH-CSP, and physicochemical properties of them were investigated by gel permeation chromatography (GPC), gas chromatography (GC), nuclear magnetic resonance (NMR), fourier transform infrared (FT-IR) spectroscopy, scanning electronic microscopy (SEM), and Congo red test. Results showed that AHP-1 (2.80 × 10⁴ Da) and AHP-2 (1.25 × 10⁴ Da) were consisted of xylose, mannose, galactose, rhamnose, arabinose, and glucose. AHP-1 and AHP-2 had strong scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-Azobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), and OH· free radicals. Furthermore, pretreatment with AHP-2 could protect the H₂O₂-injured IEC-6 cells by effectively scavenging the overproduced reactive oxygen species (ROS) and regulating of Kelch-like ECH-associated protein 1(Keap1)/ nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway.

Ameliorative effects of corn silk extract on acetaminophen-induced renal toxicity in rats

The current study aimed to investigate the protective effect of corn silk methanolic extract (CSME) against acetaminophen (APAP)-induced nephrotoxicity. The present study was carried out on 40 male Wistar albino rats, which were randomly divided into four groups (n = 10): control group, orally administered with a single dose of 1.8 ml 0.9% normal saline at the last day of the experiment; CSME group, orally received CSME (400 mg/kg BW daily for 5 weeks); APAP group, orally administered with a single dose of APAP (2 g/kg BW); and CSME and APAP group, orally administered with CSME, followed by a single oral dose of APAP. The results of this study revealed that APAP caused a significant increase in serum urea, creatinine concentrations, and malondialdehyde (MDA) concentrations in renal tissues. In addition, APAP caused a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in renal tissues compared with the control group. Furthermore, APAP caused marked renal damage as revealed by alterations in histopathological architectures of kidney tissues. APAP resulted in a marked expression of caspase 3 and nuclear factor κB (NFĸβ) within the renal tubules, while caused marked decrease of proliferating cell nuclear antigen (PCNA) immunostaining and transforming growth factor beta 1 (TGFβ 1) expression within the epithelial lining of the renal tubules. However, pre-treatment with CSME returned all biochemical parameters, histopathological changes, and immunohistochemical parameters toward normal levels as the control group. In conclusion, oral administration of CSME protected rats against APAP renal toxicity through its antioxidant, anti-apoptotic, and anti-inflammatory protective mechanisms.

Characterization, antioxidant activities, and inhibition on α-glucosidase activity of corn silk polysaccharides obtained by different extraction methods

The polysaccharides (CSPw, CSPc, CSPa, and CSPu) were prepared by hot water extraction, acid-assisted extraction, alkaline-assisted extraction, and ultrasound-assisted extraction from corn silk, respectively. High performance gel permeation chromatography (HPGPC), fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) results indicated that the extraction methods had an obvious impact on the molecular weight, structure, and morphology of the CSPs. Among the four polysaccharides, CSPu showed the highest inhibitory α-glucosidase activity, which might be related to its smaller molecular weight. Furthermore, kinetics analyses revealed that CSPu had significant inhibition of α-glucosidase in a non-reversible and competitive manner. Fluorescence quenching analysis illustrated that the interaction mechanism of CSPu and α-glucosidase was claimed as a static quenching mechanism. Isothermal titration calorimetry (ITC) analysis showed that the main driving forces for the interaction of CSPu with α-glucosidase was hydrogen bonding and the binding interactions of them occurred spontaneously.

Hepatoprotection mechanism against alcohol-induced liver injury in vivo and structural characterization of Pinus koraiensis pine nut polysaccharide

Previous studies have shown that Pinus koraiensis pine nut polysaccharide PNP80b-2 exerts widely protective effects against liver injury induced by chemical pollutants, alcohol and drugs. By comparison, PNP80b-2 exhibits the strongest hepatoprotection against alcohol-induced liver injury (AILI). Thus, the purpose of this study is to investigate the hepatoprotection mechanisms of PNP80b-2 against AILI in vivo. The results indicated that PNP80b-2 alleviated oxidative stress induced by alcohol through enhancing antioxidant capacity of hepatocytes via NRF2/HO-1 pathway. PNP80b-2 also effectively suppressed the secretion of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6, exhibiting anti-inflammatory effects via NF-κB signaling pathway in AILI. In addition, PNP80b-2 protected mice from severe DNA damage induced by alcohol through regulating the expression of Hipk2, P53, Hp1γ and Wip1. Taken together all the results, PNP80b-2 exerts hepatoprotective activity against AILI in vivo through enhancing antioxidant capacity, suppressing inflammation response and promoting DNA damage repair in livers. Furthermore, the structural features of PNP80b-2 were also characterized. PNP80b-2, with molecular weight of 23.0 kDa, was found to be composed of 1,2-linked Galf, 1,2-linked Rhap, 1,4-linked Xylp, 1,6-linked Glcp, 1,4-linked GlcpA, 1,2,6-linked Galp, 1,4,6-linked Glcp, 1,2,3,4-linked Arap, 1-linked Galp and Leu- and Ile-linked O-glycopeptide bonds, based on the GC-MS and NMR results.

Modulation of Calcium Oxalate Crystal Growth and Protection from Oxidatively Damaged Renal Epithelial Cells of Corn Silk Polysaccharides with Different Molecular Weights

Corn silk polysaccharide (CSP0; molecular weight = 124 kDa) was degraded by ultrasonication to obtain five degraded polysaccharides, namely, CSP1, CSP2, CSP3, CSP4, and CSP5, with molecular weights of 26.1, 12.2, 6.0, 3.5, and 2.0 kDa, respectively. The structures of these polysaccharides were characterized by FT-IR, 1H NMR, and 13C NMR analyses. The antioxidant activities, including scavenging ability for hydroxyl radicals and DPPH free radicals, chelation ability for Fe2+ ions, and reducing ability of CSP increased with decreased molecular weight of CSPs within 6.0 to 124 kDa. However, antioxidant activity weakened when the molecular weight of CSPs reached 3.5 and 2 kDa. CSP3 with a molecular weight of 6.0 kDa exhibited the strongest antioxidant activity. After protection with 60 μg/mL CSPs, the viability of human renal proximal tubular epithelial cells (HK-2) damaged by nano-COM crystals increased, the level of reactive oxygen species decreased, and the amount of COM crystal adhered onto the cell surface decreased. The ability of CSPs to protect cells from CaOx crystal damage was consistent with their antioxidant activity. CSPs can specifically combine with CaOx crystal to inhibit the conversion of calcium oxalate dihydrate crystal to calcium oxalate monohydrate crystal. All these results showed that the activity of CSPs was closely correlated with molecular weight. A very high or low molecular weight of CSPs was not conducive to their activity. CSPs, especially CSP3 with a molecular weight of 6.0 kDa, can be used as a potential antistone drug.

Ultrasonic-assisted enzymatic extraction of Sparassis crispa polysaccharides possessing protective ability against H2O2-induced oxidative damage in mouse hippocampal HT22 cells

Extraction optimization, structural characterization, and neuroprotective effects of polysaccharides from Sparassis crispa.

Corn silk crude polysaccharide exerts anti-pancreatic cancer activity by blocking the EGFR/PI3K/AKT/CREB signaling pathway

S1, a crude polysaccharide from corn silk, may significantly inhibit pancreatic cancer cell proliferation in vitro and in vivo. It can induce apoptosis, arrest the cell cycle in S phase and impede pancreatic cancer cell migration and invasion.

Chemical characterization, antioxidant properties and anticancer activity of exopolysaccharides from Floccularia luteovirens

Two polysaccharides, ALF1 and ALF2 were obtained from the fermentation liquid of Floccularia luteovirens. These fractions had good performance in scavenging radicals and ALF1 exhibited obvious antioxidant activities. Further, linkage analysis and NMR were used to characterize the structures of ALF1. Linkage and NMR data comprehensively showed that ALF1 mainly contained six kinds of linkage type units as →4)-β-D-Manp→, 1,3-α-Fucp→, α-L-Araf-C1→, →6)-β-D-Galp-C1→, →4)-α-D-GlcAp-(1→ and →3)-β-D-Glcp(1→. In addition, ALF1 had good bioactivities such as anticancer and antioxidant activities. ALF1 was proven to be able to inhibit tumor cells without affecting the normal cells. Besides, ALF1 improved the activities of SOD, GSH-Px and CAT, and decreased the production of MDA which result in protecting PC12 cells against H₂O₂-induced oxidative stress. ALF1 decreased ROS production, and stabilize mitochondrial membrane potential. The findings indicated that the fermentation liquid of Floccularia luteovirens could be used as a potential natural source of antioxidant.

Potential Photoprotective Effect of Dietary Corn Silk Extract on Ultraviolet B-Induced Skin Damage

Ultraviolet B (UVB) irradiation causes adverse effects on the skin. Corn silk contains flavonoids and other bioactive compounds and antioxidants, which may prevent skin photoaging through antioxidant and anti-inflammatory effects. We aimed to investigate the potential photoprotective effects of dietary corn silk on UVB-induced skin damage in mice and the mechanisms behind these effects on human skin cells. Oral administration of corn silk water extract (CS) (2 or 4 g/kg/day) for 19 weeks decreased epidermal thickness, wrinkle formation, and positive staining for PCNA, Ki67, and 8-OHdG, and increased collagen staining in UVB-irradiated SKH-1 hairless mice compared with controls. The pro-inflammatory NF-κB target genes (IL-1β, iNOS, and COX-2) and MMP-9 expressions were lower in the CS groups, and TGF-β/Smad signaling increased. Low skin lipid peroxidation and blood DNA oxidation levels and high blood glutathione were detected. Antioxidant transcription factor Nrf2-related catalase and SOD1 proteins and glutaredoxin mRNA levels increased. The results of CS extract treatment and UVB irradiation in HaCaT cells showed the same results in Nrf2 and NF-κB target genes. An LC-MS/MS analysis showed that the CS extract contained potential antioxidants, which might have contributed to its anti-photoaging effects in tissues and cells. CS extract may reduce UVB-induced skin damage through antioxidant and anti-inflammatory mechanisms.

Comparison of the adhesion of calcium oxalate monohydrate to HK-2 cells before and after repair using tea polysaccharides

Background: Kidney stone formation is closely related to renal epithelial cell damage and the adhesion of calcium oxalate crystals to cells. Methods: In this research, the adhesion of human kidney proximal tubular epithelial cells (HK-2) to calcium oxalate monohydrate crystals with a size of approximately 100 nm was studied. In addition, the inhibition of crystal adhesion by four tea polysaccharides (TPS0, TPS1, TPS2, and TPS3) with the molecular weights of 10.88, 8.16, 4.82, and 2.31 kDa, respectively were compared. Results: When oxalic acid-damaged HK-2 cells were repaired, cell viability increased. By contrast, reactive oxygen species level, phosphatidylserine eversion, and osteopontin expression decreased, thus indicating that tea polysaccharides have a repairing effect on damaged HK-2 cells. Moreover, after repairing the damaged cells, the amount of adherent crystals was reduced. The repair effect of tea polysaccharides is closely related to molecular weight, and TPS2 with the moderate molecular weight displayed the best repair effect. Conclusion: These results suggest that tea polysaccharides, especially TPS2, may inhibit the formation and recurrence of calcium oxalate kidney stones.

Repair activity and crystal adhesion inhibition of polysaccharides with different molecular weights from red algae Porphyra yezoensis against oxalate-induced oxidative damage in renal epithelial cells

Porphyra yezoensis polysaccharide repaired oxalate-injured renal epithelial cells and decreased COM crystal adhesion on the cell surface.