Que Zui tea ameliorates hepatic lipid accumulation and oxidative stress in high fat diet induced nonalcoholic fatty liver disease.

In this study, the protective effects of hot water (QW) and aqueous-ethanol extracts (QA) from Que Zui tea on non-alcoholic fatty liver disease (NAFLD) were investigated. Quantitative and qualitative analysis revealed that QW and QA were rich in polyphenols, especially 6'-O-caffeoylarbutin. Both QW and QA significantly reduced body weight and liver index, increased serum levels of high density lipoprotein cholesterol (HDL-C), and decreased the levels of total cholesterol (TC), triglyceride (TG), nonesterified free fatty acids (NEFA) and low density lipoprotein cholesterol (LDL-C) in NAFLD rats induced high fat diet. Furthermore, the contents of TC, TG, NEFA, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the liver tissues were inhibited after QW and QA administration. Histopathological examination showed that QW and QA significantly reduced liver lipid accumulation of NAFLD rats. In addition, QW and QA could enhance increase the activity of antioxidant (glutathione, superoxide dismutase and catalase) in the liver by regulation Nrf2 signaling pathway, thereby alleviating liver damage caused by lipid peroxidation. QW and QA activated AMPK/PPAR-α signaling pathway by increasing the expression of adiponectin and its receptor AdipoR2, thereby reducing fat production and enhancing fatty acid ß oxidation. These data suggested that QW and QA had the potential to in the prevention and treatment of NAFLD.

6'-O-Caffeoylarbutin from Que Zui tea ameliorates acetaminophen-induced liver injury via enhancing antioxidant ability and regulating the PI3K signaling pathway.

Que Zui tea (QT), a traditional herbal tea in China, has a significant hepatoprotective effect. 6'-O-Caffeoylarbutin (CA) is the most abundant chemical compound in the QT. However, the hepatoprotective effect of CA has not been investigated. This study is aimed to evaluate the protective effect of CA on acetaminophen (APAP) induced hepatotoxicity in vivo and in vitro and its possible underlying mechanism. In APAP-induced HepG-2 cells, CA inhibited intracellular ROS accumulation and cell apoptosis, and improved the expression of antioxidants including SOD, CAT and GSH. In APAP-administrated mice, CA pretreatment remarkably ameliorated the histopathological damage and inflammatory response, and antioxidant enzyme activity in the serum and liver tissues. Moreover, the immunohistochemistry and immunofluorescence assay results revealed that the CA markedly reduced ROS production and apoptosis, and activated antioxidant transcription factor Nrf2 in the liver. Meanwhile, molecular docking results showed that the strong binding force of CA and PI3K was due to the higher number of hydrogen- and π-bonds with active site residues. Notably, CA pretreatment significantly regulated the expression of PI3K, Akt, Nrf2, NQO1, HO-1, Bcl-2, Bax, caspase-3, and caspase-9 proteins in APAP-treated liver tissues. These data demonstrated that CA had a protective effect against APAP-induced hepatotoxicity via regulating the PI3K/Akt and Nrf2 signaling pathway.

Anti-leukemic effect and molecular mechanism of 11-methoxytabersonine from Melodinus cochinchinensis via network pharmacology, ROS-mediated mitochondrial dysfunction and PI3K/Akt signaling pathway.

Melodinus cochinchinensis (Lour.) Merr. is a Yunnan endemic folk medicine. Our previous study showed that 11-methoxytabersonine (11-MT) isolated from M. cochinchinensis has strong cytotoxicity on human T-ALL cells, but its molecular mechanism has not been studied. In current study, the cytotoxicity and possible mechanism of 11-MT on T-cell acute lymphoblastic leukemia was explored using network pharmacology and molecular biology techniques. 11-MT significantly inhibited the cell proliferations on different four human T-ALL cells (MOLT-4, Jurkat, CCRF-CEM, and CEM/C1 cells). 11-MT triggered ROS accumulation, calcium concentration and cell apoptosis, and decreased the mitochondrial membrane potential (MMP) in human T-ALL cells, especially MOLT-4 cells. Western blot analysis showed that it can induce MOLT-4 cell apoptosis by up-regulating PI3K/Akt signaling pathway. Therefore, 11-MT induces human T-ALL cells apoptosis via up-regulation of ROS-mediated mitochondrial dysfunction and down-regulation of PI3K/Akt/mTOR signaling pathway.

Potent immunosuppressive and anti-inflammatory bisindole alkaloids from Melodinus fusiformis.

Phytochemical investigation of Melodinus fusiformis led to a new aspidosperma-aspidosperma bisindole alkaloid (BIA), bis-19ß-hydroxyvenalstonidine (1), together with three known BIAs (2-4). The structures were established by extensive analysis of their HRESIMS, NMR data, and comparing with the reported data. BIA 1 is an almost symmetrical structure, linked by C3-C14' bond, while BIAs 2-4 are reported for the first time from the plant. The cytotoxic, immunosuppressive and anti-inflammatory activities of BIAs 1-4 were evaluated in vitro. BIAs 1, 3 and 4 showed good toxicity against MOLT-4 cell lines with IC50 values in the range of 1.5-17.5 -M. BIA 2 exhibited the strongest inhibitory effect against MCF-7 cell lines with an IC50 value of 7.1 µM. BIA 1 significantly inhibited Con A-stimulated mice splenocytes proliferation equal to that of the positive control (DXM) in a concentration-dependent manner. BIAs 1 and 2 were able to decrease the NO production in LPS-induced RAW 264.7 cells at 30 µM concentration. BIA 2 showed similar inhibition of nitric oxide release, compared to that of DXM. Furthermore, BIA 2 remarkably inhibited the levels of IL-6 and TNF-α compared to the LPS induced group. Interestingly, BIA 2 displayed an inhibitory effect on TNF-α production similar to that of dexamethasone at a concentration of 20 µM.

The effect of ultra-high pretreatment on free, esterified and insoluble-bound phenolics from mango leaves and their antioxidant and cytoprotective activities.

Ultra-high pressure (UHP) is a novel non-thermal pretreatment method in food processing for improving the extraction yield of polyphenols and functional properties. The present work investigated the phenolic profiles, antioxidant activities, and cytoprotective effects of the free, esterified, and insoluble-bound phenolic fractions from mango leaves before and after ultra-high pressure (UHP) treatment. UHPLC-Q-Orbitrap-MS/MS analysis resulted in the identification of 42 phenolic compounds in the different phenolic forms. UHP pretreatment could significantly influence the contents of total phenols, total flavonoids and individual compounds in the different phenolic fractions (p < 0.05). After UHP pretreatment, these phenolic fractions exhibited greater antioxidant activity, and inhibited reactive oxygen species production and cell apoptosis (p < 0.05). Meanwhile, IBP were the most potential antioxidative and cytoprotective ingredients. Therefore, UHP pretreated mango leaves with enhanced bioactivity could be used as biological agents in the health food industry to improve its application and economic values.

Phenolic constituents, antioxidant activity and neuroprotective effects of ethanol extracts of fruits, leaves and flower buds from Vaccinium dunalianum Wight.

Vaccinium dunalianum Wight is an important healthy tea resource in China with health benefits. The chemical compositions and the possible bioactive substances in its fruits, leaves and flower buds extracts (FE, LE and FBE) were identified and characterized by UHPLC-HRMS/MS. Consequently, FE, LE and FBE were rich in phenolic and flavonoid compounds. Among them, 21 compounds were identified, and the main components were chlorogenic acid, quinic acid and 6'-O-caffeoylarbutin. Furthermore, their neuroprotection and mechanism on H2O2-induced neurotoxicity in PC12 cells were investigated. All the different concentrations of FE, LE and FBE were apparently inhibited the H2O2-induced ROS generation and apoptosis on PC12 cells. FBE showed stronger neuroprotective activity against H2O2-induced PC12 cell damage than those of FE and LE. The mechanism of neuroprotective effect might be related to the upregulation of endogenous antioxidant enzymes expressions and activation of the Nrf2/HO-1 signaling pathway.

Flower extract of Caragana sinica. ameliorates DSS-induced ulcerative colitis by affecting TLR4/NF-κB and TLR4/MAPK signaling pathway in a mouse model.

OBJECTIVES: This study aimed to find out the protective effects and preliminary mechanisms of the flower extract of Caragana sinica (FEC) on dextran sulfate sodium salt (DSS)-induced colitis. MATERIALS AND METHODS: The ulcerative colitis models of mice induced by 3% DSS were established and treated with FEC. Body weight changes, disease activity index (DAI), colon histopathological score, anti-oxidant ability, and the level of inflammatory cytokines were determined. The expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) were assessed in colonic tissue by immunohistochemical staining. Western blot was used to analyze the expression of TLR4/ nuclear factor kappa-B (NF-κB) and TLR4/ mitogen-activated protein kinase (MAPK) signaling pathway-related proteins. RESULTS: FEC significantly prevented body weight loss and colonic shortening and reduced the disease activity index and histopathological score (P<0.05). Moreover, FEC treatment remarkably down-regulated the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1ß), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) and up-regulated the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and interleukin 10 (IL-10) in the colon of DSS mice (P<0.05). Furthermore, the expression of TLR4/NF-κB and TLR4/MAPK pathway-related proteins was inhibited by FEC (P<0.05). CONCLUSION: Our findings demonstrated that FEC could serve as a potential therapeutic agent for treatment of ulcerative colitis.

Antioxidant and Cytoprotective Effects of New Diarylheptanoids from Rhynchanthus beesianus.

Rhynchanthus beesianus (Zingiberaceae) has been an important food spice and vegetable in southern China. Fifteen phenolic compounds (1-15) including three new diarylheptanoids, rhynchanines A-C (1-3) and one new phenylpropanoid, 4-O-methylstroside B (9), were isolated from R. beesianus rhizomes. The structures of new compounds were elucidated by comprehensive analyses through NMR, HRMS technique, acid hydrolysis, and Mosher's reaction. Among them, compound 5 is the first isolated natural product and its NMR data are reported. Most of the isolated compounds, especially 3-6 and 8, showed significant antioxidant activities on DPPH, ABTS+ radical scavenging, and FRAP assays. Furthermore, the antioxidant phenolic compounds were evaluated for their cytoprotective capacity against H2O2-induced oxidative stress in HepG-2 cells. Compounds 3 and 5 could significantly inhibit reactive oxygen species production, and compounds 3, 5, and 6 could remarkably prevent the cell apoptosis. Then, the R. beesianus rhizome, which contained phenolic compounds, might serve as a functional food for potential application on preventing oxidative stress-connected diseases.

HRESIMS-guided isolation of aspidosperma-scandine type bisindole alkaloids from Melodinus cochinchinensis and their anti-inflammatory and cytotoxic activities.

The Melodinus species have been proved to be good resources of bisindole alkaloids. Six bisindole alkaloids were isolated from the leaves and stems of Melodinus cochinchinensis (Lour.) Merr. guided by HRESIMS data analysis. Among them, melokhanines K-M, epi-scandomelonine, and epi-scandomeline possessed aspidosperma-scandine skeleton linked by a C-C bond while meloyine II had a scandine-scandine skeleton. The structures were established by extensive spectroscopic analysis of their HRESIMS and NMR data. Melokhanines K-M were undescribed compounds, while epi-scandomelonine, epi-scandomeline and meloyine II were known compounds, which were reported from Melodinus species for the first time. The anti-inflammatory and cytotoxic activities of the isolates were also evaluated in vitro. Melokhanine K and meloyine II showed potent inhibitory activity on the production of nitric oxide, interleukin-6, and tumor necrosis factor-α in LPS-induced RAW 264.7 macrophages, whereas epi-scandomelonine and epi-scandomeline exhibited certain cytotoxic activity against MOLT-4 cells with IC50 values 5.2 and 1.5 µM, respectively.

Immunosuppressive Nor-isopimarane Diterpenes from Cultures of the Fungicolous Fungus Xylaria longipes HFG1018.

Eighteen new nor-isopimarane diterpenes, xylarinorditerpenes A-R (1-18), along with two previously reported compounds, 14α,16-epoxy-18-norisopimar-7-en-4α-ol (19) and the labdane-type diterpene agatadiol (20), were isolated from cultures of the fungicolous fungus Xylaria longipes HFG1018 isolated from the wood-rotting basidiomycete Fomitopsis betulinus. The structure elucidation and relative configuration assignments of 1-18 were accomplished by interpretation of spectroscopic data and through computational methods. The absolute configurations of 1, 4, and 16 were determined by single-crystal X-ray diffraction. Compounds 1-16 possess an 18- or 19-nor-isopimarane skeleton, and compounds 17 and 18 possess an 18,19-dinor-isopimarane skeleton. Compounds 2-5, 9, 14, 19, and 20 showed immunosuppressive activity but were devoid of cytotoxicity against the cell proliferation by concanavalin A-induced T lymphocytes and lipopolysaccharide-induced B lymphocytes, with IC50 values varying from 1.0 to 27.2 µM and from 16.1 to 51.8 µM, respectively.

New pyrazinoquinazoline alkaloids Isolated from a culture of Stenotrophomonas maltophilia QB-77.

Two new pyrazinoquinazoline alkaloids, epi-fiscalin D (1) and epi-fiscalin E (2), as well as three known analogues, norquinadoline A (3), quinadoline A (4), and fiscalin C (5), were isolated from ethyl acetate extract of the fermentation broth of Stentrophomonas maltophilia QB-77. The structures of new compounds were elucidated on the basis of extensive spectroscopic data analysis including UV, HRESIMS, and 1D and 2D NMR experiments. All the isolated compounds were tested for their in vitro cytotoxicity against five human cancer cell lines (SMMC-7721, MCF-7, HL-60, SW480, and A-549) and antibacterial activities against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus.

Novel immunosuppressive pregnane glycosides from the leaves of Epigynum auritum.

Phytochemical investigation on the leaves of Epigynum auritum led to the isolation of three novel C21 pregnane glycosides, epigynosides, E-G (1-3), together with two known pregnane glycosides, epigynosides A (4) and C (5). Their structures were elucidated based on extensive spectroscopic data (MS, IR, 1D and 2D NMR) analysis, as well as comparison with the reported data. The immunological activities of the new compounds was evaluated against concanavalin A (Con A)-stimulated proliferation of mice splenocyte in vitro. Compounds 1-3 displayed significant immunosuppressive activities, close to the efficacy of the positive control (dexamethasone) at the concentration of 50µM.

Melokhanines A-J, Bioactive Monoterpenoid Indole Alkaloids with Diverse Skeletons from Melodinus khasianus.

The new melokhanines A-J (1-10) and 22 known (11-32) alkaloids were isolated from the twigs and leaves of Melodinus khasianus. The new compounds and their absolute configurations were elucidated by extensive analysis of spectroscopic, X-ray diffraction, and computational data. Melokhanine A (1), composed of a hydroxyindolinone linked to an octahydrofuro[2,3-b]pyridine moiety, is an unprecedented monoterpenoid indole alkaloid. Melokhanines B-H (2-8) possess a new 6/5/5/6/6 pentacyclic indole alkaloid skeleton. Alkaloids 1-16, 25-27, 31, and 32 showed the best antibacterial activity against Pseudomonas aeruginosa (MIC range 2-22 µM). Among the seven dermatophytes tested, compound 1 showed significant inhibitory activity against Microsporum canis, M. ferrugineum, and Trichophyton ajelloi (MIC range 38-150 µM), i.e., half the efficacy of the positive control, griseofulvin.

Dysoxydensins A-G, seven new clerodane diterpenoids from Dysoxylum densiflorum.

Seven new clerodane diterpenoids, dysoxydensins A-G (1-7), together with six known clerodanes, were isolated from Dysoxylum densiflorum. The structures of all the compounds were elucidated by extensive spectroscopic analysis. These compounds were evaluated for their cytotoxic activities against five human cancer cell lines, and compounds 2, 3, and 5 showed moderate cytotoxic activities.

Cinchona alkaloids from Cinchona succirubra and Cinchona ledgeriana.

Seven new cinchona alkaloids, cinchonanines A-G (1-7), and 29 known alkaloids were isolated from the barks of Cinchona surrirubra and C. ledgeriana collected from Yunnan Province in China. The new structures were elucidated by extensive spectroscopic analysis. All compounds were evaluated for their cytotoxicity against five human cancer cell lines. Compounds 2, 13, 14, and 15 showed moderate cytotoxicity.

Melosuavines A-H, cytotoxic bisindole alkaloid derivatives from Melodinus suaveolens.

Eight new bisindole alkaloids, melosuavines A-C (1-3), having an aspidosperma-scandine linkage, melosuavines D-F (4-6), possessing an aspidosperma-aspidosperma skeleton, and melosuavines G and H (7 and 8) of the aspidosperma-venalatonine type, tenuicausine (9), and melodinine J (10) were isolated from the twigs and leaves of Melodinus suaveolens. The structures of 1-8 were elucidated by extensive spectroscopic methods, and compounds 9 and 10 were identified by comparison with data in the literature. The relative configuration 9 was determined from the ROESY spectrum, and some NMR signals were reassigned. Compounds 1, 2, 4-6, 8, and 10 exhibited low micromolar cytotoxicity against one or more of five human cancer cell lines.

Indole alkaloids from leaves and twigs of Rauvolfia verticillata.

Seven new indole alkaloids, rauverines A-G (1-7), and 19 known indole alkaloids were isolated from the leaves and twigs of Rauvolfia verticillata. All compounds showed no cytotoxicity against five human cancer cell lines, human myeloid leukemia (HL-60), hepatocellular carcinoma (SMMC-7721), lung cancer (A-549), breast cancer (MCF-7), and colon cancer (SW480) cells.

Cytotoxic indole alkaloids from Tabernaemontana divaricata.

Five new vobasinyl-ibogan-type bisindole alkaloids, tabernaricatines A-E (1-5), two new monomers, tabernaricatines F and G (6 and 7), and 24 known indole alkaloids were isolated from the aerial parts of Tabernaemontana divaricata. Alkaloids 1 and 2 are the first vobasinyl-ibogan-type alkaloids possessing a six-membered ring via an ether linkage between C-17 and C-21. All compounds except for 3 were evaluated for their cytotoxicity against five human cancer cell lines; conophylline showed significant bioactivity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cells with IC50 values of 0.17, 0.35, 0.21, 1.02, and 1.49 µM, respectively.

Melodinines M-U, cytotoxic alkaloids from Melodinus suaveolens.

Nine new alkaloids, melodinines M-U (1-9), and 11 known alkaloids were isolated from Melodinus suaveolens. The new structures were elucidated by extensive NMR and mass spectroscopic analyses and comparison to known compounds. All compounds were evaluated for their cytotoxicity against five human cancer cell lines. Compounds 6, 11, and 16 showed significant cytotoxicity.