Polysaccharides from Citrus grandis L. Osbeck suppress inflammation and relieve chronic pharyngitis

The Isolation, Structural Characterization and Anti-Inflammatory Potentials of Neutral Polysaccharides from the Roots of Isatis indigotica Fort

Polysaccharides have been assessed as a potential natural active component in Chinese herbal medicine with anti-inflammatory properties. However, the complex and indefinite structures of polysaccharides limit their applications. This study explains the structures and anti-inflammatory potentials of three neutral polysaccharides, RIP-A1 (Mw 1.8 × 104 Da), RIP-B1 (Mw 7.4 × 104 Da) and RIP-B2 (Mw 9.3 × 104 Da), which were isolated from the roots of Isatis indigotica Fort. with sequenced ultrafiltration membrane columns, DEAE-52 and Sephadex G-100. The planar structures and microstructures of RIP-A1, RIP-B1 and RIP-B2 were further determined by HPGPC, GC-MS, methylation analysis, FT-IR, SEM and AFM, in which the structure of RIP-A1 was elucidated in detail using 1D/2D NMR. The Raw 264.7 cells were used for the anti-inflammatory activity in vitro. The results showed that RIP-A1, RIP-B1 and RIP-B2 are all neutral polysaccharides, with RIP-A1 having the smallest Mw and the simplest monosaccharide composition of the three. RIP-A1 is mainly composed of Ara and Gal, except for a small quantity of Rha. Its main structure is covered with glycosidic linkages of T-α-Araf, 1,2-α-Rhap, 1,5-α-Araf, T-β-Galp, 1,2,4-α-Rhap, 1,3,5-α-Araf and 1,6-β-Galp with 0.33:0.12:1.02:0.09:0.45:11.41:10.23. RIP-A1 significantly inhibited pro-inflammatory cytokines (NO, TNF-α, IL-6 and IL-1β) and increased anti-inflammatory cytokines (IL-4) in LPS-stimulated RAW 264.7 cells. Moreover, RIP-A1 could significantly inhibit the mRNA expression of TNF-α, IL-6 and L-1β. It could also activate IKK, p65 and IκBα (the components of the NF-κB signaling pathway). In conclusion, the above results show the structural characterization and anti-inflammatory potentials of RIP-A1 as an effective natural anti-inflammatory drug.

Stereoselective separation, configuration determination, and quantification of flavanone glycosides in Citrus using chiral HPLC-UV in combination with CD spectra

Flavanone glucosides, such as naringin and neohesperidin, are present in specific Citrus species and manifest a chiral center at the C-2 position of their flavanone moiety. This study successfully achieved the simultaneous stereoselective separation of the C-2 diastereomers of naringin, neohesperidin and hesperidin, as well as the partial separation of narirutin using a chiral high performance liquid chromatography with ultraviolet detection method with cellulose tris(3,5-dichlorophenylcarbamate) as the stationary phase under normal-phase mode. The mobile phase comprised n-hexane and ethanol (containing 0.25% formic acid) at a proportion of 65 : 35 (v/v) with a flow rate of 0.6 mL min-1. Each single epimer of chiral flavanone glycosides was prepared using chiral semi-preparative chromatography, and the absolute configuration was then characterized by combining the experimental electronic circular dichroism detection and time-dependent density functional theory calculations. The epimer composition of each chiral flavonoid glycoside in Fructus aurantii (Zhiqiao) and Fructus aurantii immaturus (Zhishi) was determined revealing variations among herbs collected from different production regions. Additionally, the epimer composition was found to be related to the harvesting time of the herbs. Considering the safety and efficacy, the existence of epimers of different stereo-configurations should be given more attention in the quality evaluation of natural drugs.

Chemical elucidation and rheological properties of a pectic polysaccharide extracted from Citrus medica L. fruit residues by gradient ethanol precipitation

Citron (Citrus. medica L.) fruits are commonly utilized in the production of essential oil, therefore, the fruits residues turn out to be industrial byproducts. In the present study, a crude polysaccharide was extracted from citron fruit residues by hot water extraction and precipitation of ethanol (95%), after deproteinization, a major polysaccharide component (CMLP-2) was obtained by gradient ethanol precipitation (20%-80%). The physicochemical properties of CMLP-2 such as surface morphology, functional groups, and thermostability were examined by FT-IR spectroscopy, SEM, and thermogravimetric analysis. Moreover, the chemical structure of CMLP-2 was elucidated that CMLP-2 is an acidic pectic polysaccharide consisting of arabinose (Ara), galacturonic acid (GalA), and rhamnose (Rha) in a molar ratio of 4:2:1 with a molecular weight of 202.18 kDa. CMLP-2 is a novel pectic polysaccharide rich in rhamnogalacturonan I (RG-I). Moreover, rheological tests revealed that CMLP-2 solution is pseudoplastic and temperature resistant. The result could be a good basis for the utilization of Citrus medica L. fruits residues as plant-derived food additive.

Antipharyngitis Effects of Syringa oblata L. Ethanolic Extract in Acute Pharyngitis Rat Model and Anti-Inflammatory Effect of Ir-Idoids in LPS-Induced RAW 264.7 Cells

Acute pharyngitis is an inflammation of the pharyngeal mucous membrane and submucous lymphoid tissues. Unsatisfactory treatment and repeated occurrences might cause chronic pharyngitis and other complications. Syringa oblata L. (S. oblata) is a traditional Chinese medicine that exhibited a significant therapeutic effect on various inflammatory diseases. Its commercial drug Yan Li Xiao (YLX) capsule is used as a cure for the treatment of inflammatory diseases, such as bacillary dysentery, tonsillitis, bronchitis, and acute gastroenteritis. However, studies about S. oblata relieving acute pharyngitis are rare. In this study, high-performance liquid chromatography (HPLC) was used to analyze the chemical profile of S. oblata, and the bioactive phytoconstituents were isolated and identified by nuclear magnetic resonance (NMR) and mass spectrometry. An ammonia-induced acute pharyngitis rat model was established to estimate the protective effect of S. oblata in vivo for the first time. The severity of pharyngitis was observed by appearance index and HE staining. The cytokines expression was performed by ELISA. Crucial proteins expression associated with TLR4/NF-κB/MAPK and NLRP3 inflammasome signaling pathways were analyzed by western blotting and immunohistochemistry. Furthermore, the anti-inflammatory effect of isolated compounds was evaluated by suppressing lipopolysaccharide- (LPS-) induced NO generation and regulating the cytokines levels in RAW 264.7 cells. The results showed that S. oblata exhibited a protective effect in the ammonia-induced acute pharyngitis rat model, and the compounds exert potential anti-inflammatory properties against LPS-activated RAW 254.7 cells.

Phytochemical and Therapeutic Potential of Citrus grandis (L.) Osbeck: A Review

Citrus grandis or Citrus maxima, widely recognized as Pomelo is widely cultivated in many countries because of their large amounts of functional, nutraceutical and biological activities. In traditional medicine, various parts of this plant including leaf, pulp and peel are used for generations as they are scientifically proven to have therapeutic potentials and safe for human use. The main objective of this study was to review the different therapeutic applications of Citrus grandis and the phytochemicals associated with its medicinal values. In this article different pharmacological properties like antimicrobial, antitumor, antioxidant, anti-inflammatory, anticancer, antiepileptic, stomach tonic, cardiac stimulant, cytotoxic, hepatoprotective, nephroprotective, and anti-diabetic activities of the plant are highlighted. The enrichment of the fruit with flavonoids, polyphenols, coumarins, limonoids, acridone alkaloids, essential oils and vitamins mainly helps in exhibiting the pharmacological activities within the body. The vitamins enriched fruit is rich in nutritional value and also has minerals like calcium, phosphorous, sodium and potassium, which helps in maintaining the proper health and growth of the bones as well as the electrolyte balance of the body. To conclude, various potential therapeutic effects of Citrus grandis have been demonstrated in recent literature. Further studies on various parts of fruit, including pulp, peel, leaf, seed and it essential oil could unveil additional pharmacological activities which can be beneficial to the mankind.

High or low temperature extraction, which is more conducive to Triphala against chronic pharyngitis?

OBJECTIVE

Explore the effects of high-temperature reflux extraction and low-temperature decompressing inner ebullition on Triphala's chemical composition and anti-chronic pharyngitis activity.

METHODS

The network pharmacology was used to analyze the material basis, targets and pathways of Triphala for chronic pharyngitis. HPLC were used to compare the fingerprint profile and content of components between the two extracts. The antioxidant and anti-chronic pharyngitis activities of the two extracts were compared by DPPH assay and ammonia induced chronic pharyngitis model in rats.

RESULTS

The network pharmacology results showed that the active ingredients of Triphala for chronic pharyngitis are epigallocatechin-3-gallate, (+)-catechin, epicatechin, epicatechin gallate, (+)-gallocatechin, quercetin, luteolin, leucodelphinidin and other flavonoids; phenolic acids such as gallic acid and ellagic acid; alkaloids such as ellipticine, cheilanthifoline; hydrolyzed tannins such as corilagin and chebulic acid. The high-temperature reflux extract and the low-temperature decompressing inner ebullition extract have extremely significant differences in the fingerprint profile. Among them, the content of gallic acid, ellagic acid, chebulic acid, catechin, epicatechin, corilagin, quercetin, and epicatechin gallate in the reflux extract is 1.1-5.3 times as much as decompressing inner ebullition extract. The free radical scavenging ability of reflux extract is significantly stronger than that of decompression extract (p < 0.01), and it has a repairing effect on pharyngeal mucosal damage (reducing keratinization or hyperplasia of mucosal epithelium, reducing inflammatory cell infiltration and bleeding), and reducing IL-1β (P＜0.05), IL-6 (p＜0.05), TNF-α overexpression ability is stronger than the decompressing inner ebullition extract.

CONCLUSIONS

gallic acid, ellagic acid, chebulic acid, catechin, epicatechin, corilagin and epicatechin gallate are the basic aglycones or oligomers of tannin. High temperature reflux extraction can significantly promote the occurrence of the hydrolysis of tannins and significantly increases the content of these components.Therefore, its anti-chronic pharyngitis activity is enhanced. It is suggested that high temperature reflux extraction should be used in the treatment of chronic pharyngitis.

Prenylated benzenepropanoic acid analogues from the Citrus grandis (L.) Osbeck and their anti-neuroinflammatory activity

Phytochemical studies of the air-dried pericarp of Citrus grandis led to the isolation of four new compounds including three prenylated benzenepropanoic acids (2, 3 and 5) and one alkamidic glycoside (6), together with ten known compounds (1, 4 and 7-14). The structures of these compounds were determined by the NMR spectroscopy, optical rotation data and modified Mosher's method. Meanwhile, the anti-neuroinflammatory activities of all isolated compounds were evaluated by detecting the production of nitric oxide (NO) in LPS-stimulated BV2 cells. The results showed that compounds 1, 2, 5 and 13 exhibited strong inhibition effects on NO production in LPS-stimulated BV2 cells. Mechanistically, compounds 1, 2 and 5 could suppress the expressions of iNOS. In addition, compounds 1, 2 and 5 also showed obvious inhibition effects on COX-2 expression, another vital enzyme in the inflammation process, in LPS-treated BV2 cells. These findings shed light on the potent anti-neuroinflammatory effects of Citrus grandis.

Screening and Diagnosis of Chronic Pharyngitis Based on Deep Learning

Chronic pharyngitis is a common disease, which has a long duration and a wide range of onset. It is easy to misdiagnose by mistaking it with other diseases, such as chronic tonsillitis, by using common diagnostic methods. In order to reduce costs and avoid misdiagnosis, the search for an affordable and rapid diagnostic method is becoming more and more important for chronic pharyngitis research. Speech disorder is one of the typical symptoms of patients with chronic pharyngitis. This paper introduces a convolutional neural network model for diagnosis based on the typical symptom of speech disorder. First of all, the voice data is converted into a speech spectrogram, which can better output the speech characteristic information and lay a foundation for computer diagnosis and discrimination. Second, we construct a deep convolutional neural network for the diagnosis of chronic pharyngitis through the design of the structure, the design of the network layer, and the description of the function. Finally, we perform a parameter optimization experiment on the convolutional neural network and judge the recognition efficiency of chronic pharyngitis. The results show that the convolutional neural network has a high recognition rate for patients with chronic pharyngitis and has a good diagnostic effect.

Polysaccharides from Citrus grandis associate with luteolin relieves chronic pharyngitis by anti-inflammatory via suppressing NF-κB pathway and the polarization of M1 macrophages

Chronic pharyngitis is characterized as a common inflammation of the pharyngeal mucosa, and anti-inflammatory medications are the common treatment to relieve it. Polysacharides of Citrus grandis L. Osbeck (PCG) and luteolin have been reported to have anti-inflammatory activities. In this study, the protective effects of PCG and luteolin on chronic pharyngitis are evaluated and the underlying mechanisms are explored. PCG and luteolin are administrated to animal models with granuloma, ear edema and chronic pharyngitis and the effects of PCG and luteolin on disease severity are evaluated. We also evaluate the effects of PCG and luteolin on inflammatory cytokine production in macrophages stimulated with lipopolysaccharides (LPS)/interferon-gamma (IFN-γ) and detect the effects of PCG and luteolin on macrophage polarization. Finally, we evaluate the effects of PCG and luteolin on activations of LPS-induced downstream signaling pathways. PCG and luteolin alleviate the disease severity of granuloma, ear edema and chronic pharyngitis. PCG and luteolin suppress the productions of pro-inflammatory cytokines interlukin-6 (IL-6), interlukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α) in macrophages. Luteolin promotes macrophage M2 polarization by enhancing expressions of arginase (Arg1) and mannose receptor C type 1 (Mrc1). PCG and luteolin suppress nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and interferon regulatory factor 1 (IRF1), interferon regulatory factor 5 (IRF5) expression. PCG together with luteolin relieves chronic pharyngitis by anti-inflammatory via suppressing NF-κB pathway and the polarization of M1 macrophage.