Extraction, purification and antioxidant activity of polysaccharide from cold pressed oil cake of 'Tengjiao' seed

Revealing the mechanism of Zanthoxylum armatum DC. extract-induced liver injury in mice based on lipidomics

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum armatum DC. (Z. armatum) is an herbal medicine with various active ingredients and pharmacological effects. However, modern studies found that Z. armatum is hepatotoxic. The liver is the target organ for toxic effects and an important site for lipid metabolism. The effects of Z. armatum on lipid level and metabolism in the liver are still unclear.

AIM OF THE STUDY

This study aimed to analyze hepatic lipid levels, lipid metabolites and metabolic pathways of action of Z. armatum based on lipidomics, to investigate the potential hepatotoxic mechanism of Z. armatum.

MATERIALS AND METHODS

Different doses (62, 96, and 150 mg/kg) of the methanolic extract of Z. armatum (MZADC) were administered to ICR mice by gavage. The hepatotoxicity of MZADC was assessed by the liver index, serum biochemical measurements, and histopathological examination. Lipid levels measured by the serum lipid index were evaluated in the mice. Lipidomics was used to screen for differential lipid metabolism markers and lipid metabolism pathways in the liver. Western blot analysis was performed to investigate the effects of MZADC on the liver.

RESULTS

Liver index values and serum alanine transaminase and aspartate transaminase levels were increased in the MZADC group. Histopathology examination revealed hepatocyte necrosis, watery degeneration of the hepatocytes, and hepatic cord rupture in the livers of mice. Serum levels of low-density lipoprotein cholesterol, cholesterol, and triglycerides were elevated, and high-density lipoprotein cholesterol levels were decreased. Lipidomics screening for markers of differential lipid metabolism in the liver, and altered profiles of differential metabolites indicated that glycerophospholipid metabolism, linoleic acid metabolism, alpha-linolenic acid metabolism, glycosylphosphatidylinositol-anchored biosynthesis, sphingolipid metabolism and arachidonic acid metabolic pathways were significantly associated with MZADC-induced liver injury. Western blots confirmed that the protein expression of LC3, Beclin-1, ATG5, ATG12 and ATG16L1 was decreased, and p62 was increased in the MZADC group. The proportion of p-PI3K/PI3K and p-AKT/AKT was increased.

CONCLUSIONS

The liver injury induced by MZADC involved many different lipid metabolites and lipid metabolic pathways, which may be related to autophagy. This study provides a new perspective on the hepatotoxicity study of Z. armatum and provides a reference for the safe application of Z. armatum in the medicine and food fields.

Preparation, Characterization, and Antioxidant Activities of Extracts from Amygdalus persica L. Flowers

A novel water-soluble Amygdalus persica L. flowers polysaccharide (APL) was successfully isolated and purified from Amygdalus persica L. flowers by hot water extraction. Its chemical components and structure were analyzed by IR, GC-MS, and HPLC. APL consisted of rhamnose, arabinose, mannose and glucose in a molar ratio of 0.17:0.034:1.0:0.17 with an average molecular weight of approximately 208.53 kDa and 15.19 kDa. The antioxidant activity of APL was evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 3-ethylbenzthiazoline-6-sulfonic acid (ABTS), Hydroxyl radical scavenging, Superoxide radical scavenging, and the reducing power activity was also determined in vitro. Besides, in vivo antioxidant experiment, zebrafish (Danio rerio) embryos were treated with different concentrations of APL and then exposed to LPS to induce oxidative stress. Treatment with APL at 50 or 100 µg/mL significantly reduced LPS-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of APL. Moreover, the effect of APL on zebrafish depigmentation was tested by analyzing the tyrosinase activity and melanin content of zebrafish embryos. APL showed a potential reduction in the total melanin content and tyrosinase activity after treatment. This work provided important information for developing a potential natural antioxidant in the field of cosmetics and food.

Rattan Pepper Polysaccharide Regulates DSS-Induced Intestinal Inflammation and Depressive Behavior through Microbiota-Gut-Brain Axis

Inflammatory bowel disease (IBD) is a chronic and recurrent disease. Increasing evidence suggests a higher incidence of depression in IBD patients compared with the general population, but the underlying mechanism remains uncertain. Rattan pepper polysaccharide (RPP) is an important active ingredient of rattan pepper, yet its effects and mechanisms on intestinal inflammation and depression-like behavior remain largely unknown. This study aims to investigate the ameliorating effect of RPP on dextran sulfate sodium salt (DSS)-induced intestinal inflammation and depression-like behavior as well as to reveal its mechanism. Our results indicate that RPP effectively ameliorated intestinal microbiota imbalance and metabolic disorders of short-chain fatty acids (SCFAs) and bile acids in mice with DSS-induced inflammation, contributing to the recovery of intestinal Th17/Treg homeostasis. Importantly, RPP effectively alleviated brain inflammation caused by intestinal inflammatory factors entering the brain through the blood-brain barrier. This effect may be attributed to the inhibition of the TLR4/NF-κB signaling pathway, which alleviates neuroinflammation, and the activation of the CREB/BDNF signaling pathway, which improves synaptic dysfunction. Therefore, our findings suggest that RPP may play a role in alleviating DSS-induced gut inflammation and depression-like behavior through the microbiota-gut-brain axis.

The establishment of comprehensive quality evaluation model for flavor characteristics of green Sichuan pepper (Zanthoxylum armatum DC.) in Southwest China

In this study, the quality indexes and sensory evaluation of Zanthoxylum armatum DC. from the main production areas in Southwest China were analyzed. Further, correlation analysis (CRA), principal component analysis (PCA) and cluster analysis (CA) were used to comprehensively evaluate the quality characteristics of Z. armatum. The results showed that the sensory indexes and physicochemical indexes of Z. armatum were significantly correlated. Five principal component factors were extracted from 12 indexes by PCA, and a comprehensive evaluation model of quality was established with Y = 0.2943Y₁ + 0.2387Y₂ + 0.1896Y₃ + 0.1679Y₄ + 0.1094Y₅. On this basis, 21 producing areas were grouped into 4 groups and 3 groups by Q-type CA, respectively. R-type CA showed that the content of hydroxyl-sanshools, linalool content and b* value were the quality characteristic indexes of Z. armatum in Southwest China. This work provided an important theory and practice reference for Z. armatum quality evaluation and in-depth product development.

Alkylamides from Zanthoxylum armatum DC. and their neuroprotective activity

Zanthoxylum armatum DC. is an important medicinal plant, and its pericarps are commonly used as a natural spice in Asian countries. In this study, fifteen alkylamides were isolated and elucidated from the pericarps of Z. armatum, including five undescribed alkylamides (1-5) and ten known compounds (6-15). The molecular structures of all compounds were elucidated by 1D and 2D NMR spectroscopic analysis and mass spectrometry, among which the absolute configuration of compound 15 was determined by the Mo₂(OAc)₄-induced circular dichroism method. Moreover, all compounds were screened for their neuroprotective activity against H₂O₂-induced oxidative stress in human neuroblastoma SH-SY5Y cells for the evaluation of their neuroprotective activity. Especially, compounds 2-4 expressed potential neuroprotective activity, and further research showed that the cell viability was significantly enhanced in a concentration dependent manner when the cells were treated for 6 h. Moreover, compounds 2-4 could decrease reactive oxygen species accumulation. This paper enriched structure types of alkylamides in Zanthoxylum armatum.

Extraction optimization and characterization of persimmon peel pectin extracted by subcritical water

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Persimmon peel pectin (PPP) was extracted by subcritical water.

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PPP had low M_w of 21.79 kDa and its degree of esterification was 40.61 %.

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PPP attributed to a degradation temperature of 228.05 ℃.

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The IC₅₀ of PPP to ABTS•+ was 9.8-times that of commercial citrus pectin in vitro.

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PPP altered microbial intestinal communities in mice.

Persimmon peel pectin (PPP) was extracted by subcritical water via the response surface methodology. The optimal crude PPP extraction yield of 7.62 ± 0.7 % was found at 138 °C, 2.84 min, and liquid–solid ratio of 1:10.02. After treatment of deproteinization and decolorization with papain and hydrogen peroxide, 83.19 % of protein and 78.56 % of the colour in crude PPP were removed, respectively. PPP owned the M_w of 21.79 kDa and its uronic acids content was 64.03 %. PPP was further affirmed by fourier transform infrared, X-ray diffractometer and ¹H NMR analysis. Moreover, the degradation temperature (228.05 ℃) of PPP was verified via differential scanning calorimetry. Then, the IC₅₀ of PPP to ABTS•+ was 9.8 times that of commercial citrus pectin. Moreover, PPP could change microbial communities and selectively enrich Bacteroides, Cetobacterium, Erysipelatoclostridium, Parabacteroides and Phocaeicola sartorii. This study demonstrated that subcritical water was practicable for extraction of persimmon peel pectin.

Isolation, Structural Analysis and Anti-Inflammatory Activity of a Polysaccharide from Ilex cornuta Fruits

In the present study, a polysaccharide from Ilex cornuta fruits (LCFP-3) was obtained by hot water extraction, Diethyaminoethyl cellulose-52 (DEAE-52) chromatography column and Sephadex G-100 gel column purification. Its structural characteristics were further explored using high performance anion exchange chromatography (HPAEC), gas chromatography and mass spectrometry (GC/MS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Monosaccharide composition analysis revealed LCFP-3 contained mainly Galactose (31.92 %), Arabinose (25.87 %) and Galacturonic acid (23.35 %) while small percentage of Rhamnose, Glucose, Mannose and Xylose. Chemical composition analysis showed that the total sugar content of LCFP-3 was 90.31 % and the protein content was 0.246 %. Gel permeation chromatography (GPC) analysis showed that its average molecular weight was 41.199 kDa. Structural analysis showed that LCFP-3 may be composed of residues, T-α-Arap, T-α-Rhap, 1,3-α-Arap, 1,4-α-Arap, T-β-Galp, 1,4-α-GalpA(OMe), 1,4-β-Glcp, 1,3-β-Galp, 1,3,6-β-Manp, 1,6-β-Galp, 1,3,4-β-GalpA, 1,4,6-β-Manp, 1,3,6-β-Glcp, 1,2,3,4-α-Xylp. The anti-inflammatory activity of LCFP-3 was evaluated using lipopolysaccharide (LPS)-induced RAW246.7 macrophages. The results showed that 1-200 μg/mL LCFP-3 could dose-dependently protect against LPS-induced toxicity and 1 μg/mL LCFP-3 could significantly inhibit LPS-induced NO production. Therefore, LCFP-3 exerted an anti-inflammatory activity and has great potential as a functional ingredient.

Silk protein/polyvinylpyrrolidone nanofiber membranes loaded with puerarin accelerate wound healing in mice by reducing the inflammatory response

In modern clinical applications, wound healing remains a considerable challenge. Excessive inflammatory response is associated with delayed wound healing. In this study, we prepared composite nanofibrous membranes by mixing the Chinese herbal extract puerarin (PUE) with natural silk protein (SF) and synthetic polymer polyvinylpyrrolidone (PVP) using electrostatic spinning technique, and conducted a series of studies on the structural and biological properties of the fibrous membranes. The results showed that the loading of PUE increased the diameter, porosity and hydrophilicity of nanofibers, which were more favorable for cell adhesion and proliferation. ABTS radical scavenging assay also showed that the loading of PUE enhanced the antioxidant properties of the fibrous membranes. In addition, SF/PVP/PUE nanofibers are non-toxic and can be used as wound dressings. In vitro experiments showed that SF/PVP/PUE nanofibers could effectively alleviate lipopolysaccharide (LPS)-induced inflammation in Immortalized human keratinocytes (HaCaT) cells and down-regulate pro-inflammatory cytokine expression in cells. In vivo studies further showed that the SF/PVP/PUE nanofibers could effectively accelerate wound repair. The mechanism is that SF/PVP/PUE nanofibers can inhibit the activation and transduction of toll-like receptor 4/myeloid differentiation factor88/nuclear factor kappa B (TLR4/MyD88/NF-κB) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathways, thereby reducing the inflammatory response and achieving wound healing.

Ultrasound-assisted extraction of polysaccharide from spent Lentinus edodes substrate: Process optimization, precipitation, structural characterization and antioxidant activity

Lentinus edodes is the second-most popular and cultivated mushroom worldwide due to its nutritional and health-promoting benefit. However, the mushroom production generates vast amounts of spent L. edodes substrate (SLS) that is generally discharged into the environment, posing a great challenge within mushroom by-product valorization. In this work, SLS polysaccharide (SP) was ultrasonically extracted by optimizing the process conditions with response surface methodology. Using gradient ethanol precipitation, SP was separated into SP40, SP60 and SP80, and their monosaccharide composition, structural properties, and antioxidant potential were further characterized and compared. The results showed the total polysaccharide content reached up to 37.05 ± 0.31 mg/g under the optimal conditions including an extraction temperature of 50 °C, a liquid-solid ratio of 30 mL/g and an ultrasonic power of 120 W. SP and its fractional precipitations were heteropolysaccharides sharing a similar monosaccharide composition including L-rhamnose, D-glucuronic acid, D-galacturonic acid, d-glucose and D-xylose, and a typical infrared spectrum for polysaccharide. These fractions also varied in the surface morphology, where SP80 was looser and more porous than SP40 and SP60. Furthermore, SP and SP80 displayed the strongest antioxidant activities in vitro. This study identified a novel and practical strategy to valorize SLS for valuable polysaccharide.

Physicochemical Properties and Skin Protection Activities of Polysaccharides from Usnea longissima by Graded Ethanol Precipitation

Four Usnea longissima polysaccharides (ULPs; ULP15, ULP30, ULP50, and ULP70) were obtained from the lichen U. longissima via water extraction and graded ethanol precipitation. The obtained ULPs were all heteropolysaccharides with a few proteins, with which glucose was the major monosaccharide composition. With the increase in the precipitated ethanol concentrations, the content of galactose, xylose, and mannose increased, whereas that of glucose decreased. Moreover, the antioxidant activity test demonstrated that ULP15 exhibited better reducing power and stronger scavenging ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl free radicals. Importantly, ULP15 also had a better proliferative effect on human HaCaT keratinocytes and dermal fibroblasts. Meanwhile, ULP15 protected HaCaT keratinocytes from UVB-induced proliferation inhibition and exhibited tyrosinase inhibition activity. Therefore, this work provides interesting insight into the preparation of cosmetic ingredients using the polysaccharide ULP15.

Effect of steam explosion pretreatment on the structure and bioactivity of Ampelopsis grossedentata polysaccharides

Steam explosion (SE) was a friendly environmentally pretreatment method. In this study, the effect of steam explosion (SE) pretreatment on structure and α-glucosidase inhibitory activity of Ampelopsis grossedentata polysaccharides was evaluated. Two novel polysaccharides (AGP and AGP-SE) were extracted, isolated, purified and analyzed by NMR, FT-IR and methylation. The results indicated that AGP mainly consisted of Rha, Xyl, Glc, and Ara with a molecular weight of 2.74 × 10³ kDa and AGP-SE mainly consisted of Man, Ara, and Gal with a molecular weight of 2.14 × 10³ kDa. Furthermore, the backbone of AGP and AGP-SE were mainly composed of 5)-Araf-(1→, -Glcp-(1→, 6)-Glcp-(1→, 6)-Galp-(1→, 3,6)-Manp-(1→, and 2,3,6)-Glcp-(1→. Finally, we demonstrated that all polysaccharides exhibited obviously α-glucosidase inhibition activity and mixed type inhibition. AGP-SE had better α-glucosidase inhibition activity and the binding affinity KD on α-glucosidase by using Surface Plasmon Resonance (SPR) than AGP. Overall, SE pretreatment is an effective method for extracting polysaccharide and provides a new idea into the improvement of biological activity.