Optimized Extraction of Phenolics from Jujube Peel and Their Anti-inflammatory Effects in LPS-Stimulated Murine Macrophages

Infection of PRRSV inhibits CSFV C-strain replication by inducing macrophages polarization to M1

It is a common sense that porcine reproductive and respiratory syndrome virus (PRRSV) infection could cause immune failure of classical swine fever (CSF) vaccine, and porcine alveolar macrophages (PAMs) are the target cells of both. To elucidate the role of macrophage polarization in PRRSV infection induced CSF vaccine failure, an immortal porcine alveolar macrophage line PAM39 cell line was used to investigate the effect of PRRSV or/and CSFV C-strain (CSFV-C) infection on macrophage polarization in vitro. Interestingly, PRRSV single infection or PRRSV co-infection with CSFV-C promoted PAM39 cells to M1, while CSFV-C single infection induced PAM39 cells to M2. After the construction of M1 and M2 PAM39 cells polarization models, M1 polarized PAM39 cells were found to inhibit the replication of CSFV-C, and Chinese medicine such as matrine, ginsenosides and astragalus polysaccharides could alleviate the polarization of PAM39 cells and the replication of CSFV-C. Furthermore, interferon (IFN)-γ and lipopolysaccharide (LPS) co-stimulation induced NF-κB activation while matrine treatment blocked M1 polarization-induced NF-κB pathway activation. These findings provided a theoretical basis for designing a new strategy to improve the immune effect of CSFV-C based on porcine alveolar macrophage polarization subtypes.

Astragalus polysaccharide alleviated the inhibition of CSFV C-strain replication caused by PRRSV via the TLRs/NF‑κB/TNF-α pathways

It is a common phenomenon that PRRSV infection can interfere with the protective efficacy of the CSFV vaccine in clinical settings, and no effective treatment is available. In our previous study, we found that PRRSV infection could inhibit the replication of CSFV-C by promoting the high expression of inflammatory cytokines. In order to further investigate whether Chinese medicine could alleviate the inhibition effect, the PAM39 cells model, which was co-infected with PRRSV and CSFV-C, was established. The effects of Chinese medicine on this co-infection model, as well as the effect of astragalus polysaccharide on the TLRs/NF-κB/TNF-α pathways, were investigated. Our results demonstrated that PAM39 cells inoculated with different pathogenic PRRSV significantly inhibited the replication of CSFV-C and up-regulated the major inflammatory mediators, including TNF-α. For the following studies, 50 µM of astragalus polysaccharide was selected from six kinds of representative Chinese medicine based on their cytotoxicity, viral titers, and inflammatory mediators. Further experiments indicated that astragalus polysaccharide could alleviate the inhibition of CSFV-C replication in the co-infection group with no influence on cell viability. In addition, astragalus polysaccharide treatment clearly reduced P65 phosphorylation and down-regulated the expression of TLR7, TLR9, and TNF-α in co-infection group, implying that the TLRs/NF-κB/TNF-α pathways may play an important role in astragalus polysaccharide's anti-inflammatory response. In conclusion, astragalus polysaccharide treatment alleviated PRRSV-mediated inhibition of CSFV-C replication via the TLRs/NF-κB/TNF-α pathways, and the molecular mechanism of PRRSV co-infection leading to the failure of CSFV vaccine immunization was partially elucidated, providing a scientific basis for effective CSF prevention and control in pig farms.

Jujube peel polyphenols synergistically inhibit lipopolysaccharide-induced inflammation through multiple signaling pathways in RAW 264.7 cells

Jujube has great potential as food and traditional drugs in several countries. To study the anti-inflammatory influence of jujube peel polyphenols in lipopolysaccharide (LPS) induced RAW 264.7 cells through mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB) and nuclear erythroid 2-related factor 2 (Nrf2) signaling pathways. In this study, the phenolic composition of polyphenols in jujube peel was analyzed using LC-MS/MS, and which was confirmed that the main polyphenols were p-coumaric acid, catechin and rutin. Meanwhile, jujube peel polyphenols attenuated the generation of TNF-α, IL-1β, IL-6, NO and PGE₂ by inhibiting MAPK and NF-κB signaling pathways. Additionally, jujube peel polyphenol activate Nrf2 from the cytoplasm to the nucleus, regulate antioxidant enzymes and pro-inflammatory cytokines, and reduce oxidative stress and inflammatory responses. Results obtained from this study suggest that jujube peel polyphenols may alleviate oxidative stress and inflammation by inhibiting MAPK and NF-κB and activating Nrf2 signaling pathways. Furthermore, jujube peel polyphenols have a synergistic effect in the treatment of LPS-induced inflammatory in RAW 264.7 cells. In conclusion, this study not only reveals the mechanism by which jujube peel polyphenols inhibit LPS-induced inflammation in RAW 264.7 cells, but also provides guidance for the development of new anti-inflammatory drugs.

Ultrasound-assisted adsorption/desorption of jujube peel flavonoids using macroporous resins

The work explored the process of ultrasound-assisted adsorption/desorption to efficiently purify jujube peel flavonoids (JPFs) using macroporous resins (MRs). The impact of ultrasound power and temperature on the adsorption/desorption features of JPFs on MRs were studied. The maximum adsorption (80.21 ± 2.11 mg/g) /desorption (76.22 ± 1.68 mg/g) capacity of total flavonoids content were obtained. The pseudo-second-order kinetic and Freundlich isotherm models better described the whole process of ultrasound-assisted adsorption. The adsorption process was spontaneous, physical, and dominated by multilinear intraparticle diffusion. Ultrasound mainly enhanced the adsorption capacity by strengthening the formation of hydrogen bonds and increasing the surface roughness of MRs. Besides, the principal individual flavonoid ((+)-Catechin, (-)-Epicatechin, Rutin, Quercetin-3-O-robinobioside) content of JPFs in ultrasound treatment was 2-3 times that of shaking treatment, and biological activities were significantly increased. Overall, as a low-cost green technology, ultrasound can improve the properties of MRs and better purify JPFs.

Bioactive constituents of Mosla chinensis-cv. Jiangxiangru ameliorate inflammation through MAPK signaling pathways and modify intestinal microbiota in DSS-induced colitis mice

BACKGROUND

Mosla chinensis Maxim. cv. Jiangxiangru (JXR), a traditional Chinese medicine, commonly used for the therapy of cold, fever, diarrhea, digestive disorders, and other diseases. Inflammatory bowel disease (IBD) is a chronic disorder of the human gastrointestinal tract. Research about the effect of JXR on IBD and the active ingredient composition of JXR remains deficiency.

PURPOSE

This study aims to determine the phytochemical composition and the anti-inflammatory property of JXR, as well as the possible anti-inflammatory mechanisms.

METHODS

The bioactive profile of JXR extracts was determined by UPLC-LTQ-Orbitrap-MS. A DSS induced colitis mouse model was applied to explore the anti-inflammatory activity of JXR. The body weight, colon length and histopathological status of colon tissue were evaluated. The content of inflammatory mediators (nitric oxide (NO), prostaglandin E₂ (PGE₂)) and cytokines (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β)), corresponding mRNA and protein expression levels were analyzed. Oxidation pressure and gut microbial composition were also explored.

RESULTS

Totally 63 constitutes were identified from JXR, among them, phenolic acids and flavonoids comprised a large part, and rosmarinic acid (RA) was the main compound. The results of DSS-induced colitis mice model indicated that JXR effectively ameliorated inflammation, restore the redox balance in the gut. JXR treatment significantly reduced the production of reactive oxygen species (ROS), increased the activity of antioxidative enzyme, suppressed the secretion of inflammatory mediators (NO, PGE₂) and cytokines (TNF-α, IL-6, IL-1β). JXR also restrained the activation of mitogen-activated protein kinases (MAPKs) signaling pathway. Furthermore, JXR could restore the microbial diversity by suppressing Bacteroidaceae, increasing Bifidobacteriales and Melainabacteria in DSS colitis mouse model.

CONCLUSIONS

This study demonstrated that JXR composed with various bioactive compounds, effectively ameliorated colitis, restored the redox balance and regulated gut microbiota. Results from the present study provide an insight of therapeutic potential of JXR in IBD based on its anti-inflammatory and antioxidant properties, also provide a scientific basis for using JXR as a functional ingredient to promote colon health.

Combination of pipette tip solid phase extraction and high performance liquid chromatography for determination of plant growth regulators in food samples based on the electrospun covalent organic framework/polyacrylonitrile nanofiber as highly efficient sorbent

Facile and sensitive determination of plant growth regulators (PGRs) in food samples is important but still remains great challenge. Herein, a pipette tip solid phase extraction (PT-SPE) method was developed for fast and sensitively detecting PGRs. The PT-SPE adsorbent was prepared by integrating a novel covalent organic framework (COF) of schiff base network 3 (SNW-3) and polyacrylonitrile (PAN) through electrospinning. The SNW-3 can easily adsorb PGRs with high special affinity through electrovalent bands between the ammonium ions of SNW-3 and the carboxy groups of PGRs. The polymer of PAN acts as scaffold material for SNW-3, which can lower seepage pressure hence accelerates adsorption/desorption kinetics. By combination with HPLC-DAD, a satisfactory method was successfully developed for simultaneous determination of ten PGRs in watermelon. Good analytical performances were achieved with this proposed method, including good linearity (5-500 ng/mL) with high correlation coefficients (R ≥ 0.9981), low limits of detection (S/N = 3, 0.24-3.19 ng/mL) and limits of quantification (S/N = 10, 1.65-5.72 ng/mL), satisfactory precision (intra-day RSDs ≤ 2.7%, inter-day RSDs ≤ 3.7%), and high accuracy (recovery: 82.8-113.0%). The method developed in this study shows high potential for design of high target-affinity adsorbents for food sample preparing.

Cocktail enzyme-assisted alkaline extraction and identification of jujube peel pigments

Jujube peel (JP) is rich in pigments, which appears red to deep red in color. This study optimized conditions for cocktail enzyme-assisted extraction of jujube peel pigments based on response surface method (RSM). A Box-Behnken design (BBD) was utilized to analyze the effects of buffer liquid volume (BLV), pH, temperature, and incubation time on the total polyphenols content (TPC), total flavonoids content (TFC) and color (L*, a*, b*). Optimal extraction conditions, for the highest concentrations of TPC, TFC and a* values, were 16 mL BLV, pH 7.0, temperature 43 °C, and incubation time 97 min. Finally, concentrations and identities of the eight main constituents (p-coumaric acid, (-)-epicatechin, quercetin-3-O-robinobioside, rutin, kaempferol 3-O-robinobioside, quercetin 3-O-α-l-arabinosyl-(1 → 2)-α-l-rhamnoside, quercetin 3-O-β-d-xylosyl-(1 → 2)-α-l-rhamnoside, quercetin) in jujube peel pigments were determined using UPLC-MS/MS. The study provides guidance for valorisation of jujube peel, specifically valuable food-safe pigments, during industrial production.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.

Changes in Allergenicity of Ovalbumin in Vitro and in Vivo on Conjugation with Quercetin

A previous study demonstrated decreased allergenicity in vitro of some food allergens after conjugation with polyphenols. However, little is known about how polyphenol conjugation with food allergens affects in vivo allergenicity. We conjugated a well-known food allergen, ovalbumin (OVA), with quercetin (QUE) to assess the potential allergenicity of OVA in vitro and in vivo in a BALB/c mouse model. QUE could covalently conjugate with OVA and changed the protein structure, which might destroy and/or mask OVA epitopes. Conjugation with QUE decreased IgE binding properties and the release capacity of the conjugated OVA. In vivo, as compared with native protein, conjugation with QUE decreased the levels of IgE, IgG1, IgG, plasma histamine, and mast cell protease-1 (mMCP-1) on the surface of sensitized mast cells, along with decreased FcεRI⁺ and c-kit⁺ expression. The levels of Th2-related cytokines (IL-4, IL-5, IL-13) decreased and that of a Th1-related cytokine (IFN-γ) increased slightly, which suggests that conjugation with QUE modulated the imbalance of the Th1/Th2 immune response. Conjugation of OVA with QUE could reduce OVA allergenicity in vitro and in vivo, which could provide information for reducing food allergenicity by conjugation with polyphenols.

Review of Distribution, Extraction Methods, and Health Benefits of Bound Phenolics in Food Plants

Phenolic compounds are important functional bioactive substances distributed in various food plants. They have gained wide interest from researchers due to their multiple health benefits. There are two forms of phenolic compounds: free form and bound form. The latter is also called bound phenolics (BPs), which are found mainly in the cell wall and distributed in various tissues/organs of the plant body. They can either chemically bind to macromolecules and food matrixes or be physically entrapped in food matrixes and intact cells. Various isolation methods, including chemical, biological, and physical methods, have been employed to extract BPs from plants. BPs have been shown to have strong biological activities, including antioxidant, probiotic, anticancer, anti-inflammation, antiobesity, and antidiabetic effects as well as beneficial effects on central nervous system diseases. This review summarizes research findings on these topics to help in better understanding of BPs and provide comprehensive information on their health effects.

Adhesion and anti-inflammatory potential of Lactobacillus rhamnosus GG in a sea buckthorn based beverage matrix

A seabuckthorn based beverage matrix retains the functionality of L. rhamnosus GG and exhibits enhanced anti-inflammatory effects against LPS-induced inflammation in zebrafish.

Matrine inhibits IL-1β secretion in primary porcine alveolar macrophages through the MyD88/NF-κB pathway and NLRP3 inflammasome

Our previous studies demonstrated that matrine directly acts on the replication process of porcine reproductive and respiratory syndrome virus (PRRSV). Matrine inhibits viral replication and is also associated with the NF-κB signalling pathway. These results suggest that matrine has antiviral and anti-inflammatory effects. However, the specific anti-inflammatory mechanism of matrine is still unclear. In this study, we investigated the anti-IL-1β mechanism of matrine, as IL-1β is a major inflammatory cytokine, in porcine alveolar macrophages (PAMs) stimulated with 4 μg PRRSV 5′-untranslated region (UTR) RNA and 1 μg/mL LPS. After 5′UTR RNA and LPS co-stimulation of PAMs for 12 h, the expression of IL-1β, IL-6, IL-8 and TNF-α was significantly increased. The results also showed that co-stimulation induced the expression of MyD88, and activated the NF-κB signalling pathway and NLRP3 inflammasome. Furthermore, matrine treatment downregulated MyD88, NLRP3 and caspase-1 expression, inhibited ASC speck formation, suppressed IκBα phosphorylation, and interfered with the translocation of NF-κB from the cytoplasm to the nucleus. These results suggest that matrine plays an important role in PAMs co-stimulated with PRRSV 5′UTR RNA and LPS via its effect on NF-κB and the NLRP3 inflammasome. These findings lay the foundation for the exploration of the clinical application of matrine in PRRSV disease.