Regulatory Mechanism of Mangiferin Combined with Bortezomib on Malignant Biological Behavior of Burkitt Lymphoma and Its Effect on Expression of CXC Chemokine Receptors / 中国实验血液学杂志

OBJECTIVE@#To analyze the effects of mangiferin combined with bortezomib on the proliferation, invasion, apoptosis and autophagy of human Burkitt lymphoma Raji cells, as well as the expression of CXC chemokine receptors (CXCRs) family, and explore the molecular mechanism between them to provide scientific basis for basic research and clinical work of Burkitt lymphoma.@*METHODS@#Raji cells were intervened with different concentrations of mangiferin and bortezomib alone or in combination, then cell proliferation was detected by CCK-8 assay, cell invasion ability was detected by Transwell chamber method, cell apoptosis was detected by Annexin V/PI double-staining flow cytometry, apoptosis, autophagy and Akt/mTOR pathway protein expression were detected by Western blot, and the expression changes of CXCR family was detected by real-time quantitative PCR (RT-qPCR).@*RESULTS@#Different concentrations of mangiferin intervened Raji cells for different time could inhibit cell viability in a concentration- and time-dependent manner (r =-0.682, r =-0.836). When Raji cells were intervened by combination of mangiferin and bortezomib, compared with single drug group, the proliferation and invasion abilities were significantly decreased, while the apoptosis level was significantly increased (P <0.01). Mangiferin combined with bortezomib could significantly up-regulate the expression of pro-apoptotic protein Bax and down-regulate the expression of anti-apoptotic protein Bcl-2 after intervention in Raji cells. Caspase-3 was also hydrolyzed and activated, and then induced the apoptosis of Raji cells. Mangiferin combined with bortezomib could up-regulate the expression of LC3Ⅱ protein in Raji cells, and the ratio of LC3Ⅱ/LC3Ⅰ in cells was significantly up-regulated compared with single drug or control group (P <0.01). Mangiferin combined with bortezomib could significantly inhibit the phosphorylation levels of Akt and mTOR, inhibit the proliferation and invasion of Raji cells by inhibiting Akt/mTOR pathway, and induce cell autophagy and apoptosis. Mangiferin and bortezomib could down-regulate the expressions of CXCR4 and CXCR7 mRNA after single-agent intervention in Raji cells, and the down-regulations of CXCR4 and CXCR7 mRNA expression were more significant when the two drugs were combined (P <0.01). Mangiferin alone or combined with bortezomib had no significant effect on CXCR5 mRNA expression in Raji cells (P >0.05), while the combination of the two drugs could down-regulate the expression of CXCR3 (P <0.05).@*CONCLUSION@#Mangiferin combined with bortezomib can synergistically inhibit the proliferation and invasion of Raji cells, and induce autophagy and apoptosis. The mechanism may be related to the inhibition of Akt/mTOR signaling pathway, down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of pro-apoptotic protein Bax, and the inhibition of the expression of CXCR family.

A new xanthone from hulls of Garcinia mangostana and its cytotoxic activity / 中国中药杂志

Eight compounds were isolated from ethyl acetate fraction of 80% ethanol extract of the hulls of Garcinia mangostana by silica gel, Sephadex LH-20 column chromatography, as well as prep-HPLC methods. By HR-ESI-MS, MS, 1D and 2D NMR spectral analyses, the structures of the eight compounds were identified as 16-en mangostenone E(1), α-mangostin(2), 1,7-dihydroxy-2-(3-methy-lbut-2-enyl)-3-methoxyxanthone(3), cratoxyxanthone(4), 2,6-dimethoxy-para-benzoquinone(5), methyl orselinate(6), ficusol(7), and 4-(4-carboxy-2-methoxyphenoxy)-3,5-dimethoxybenzoic acid(8). Compound 1 was a new xanthone, and compound 4 was a xanthone dimer, compound 5 was a naphthoquinone. All compounds were isolated from this plant for the first time except compounds 2 and 3. Cytotoxic bioassay suggested that compounds 1, 2 and 4 possessed moderate cytotoxicity, suppressing HeLa cell line with IC_(50) va-lues of 24.3, 35.5 and 17.1 μmol·L~(-1), respectively. Compound 4 also could suppress K562 cells with an IC_(50) value of 39.8 μmol·L~(-1).

Chemical constituents from stems and leaves of Cratoxylum cochinchinense and their inhibitory effects on proliferation of synoviocytes in vitro / 中国中药杂志

The chemical constituents from the stems and leaves of Cratoxylum cochinchinense were isolated and purified using silica gel, ODS gel, and Sephadex LH-20 gel column chromatography, as well as preparative HPLC. The chemical structures of all isolated compounds were identified on the basis of their physicochemical properties, spectroscopic analyses, and the comparison of their physicochemical and spectroscopic data with the reported data in literature. As a result, 21 compounds were isolated from the 90% ethanol extract of the stems and leaves of C. cochinchinense, which were identified as cratocochine(1), 1-hydroxy-3,7-dimethoxyxanthone(2), 1-hydroxy-5,6,7-trimethoxyxanthone(3), ferrxanthone(4), 3,6-dihydroxy-1,5-dimethoxyxanthone(5), 3,6-dihydroxy-1,7-dimethoxyxanthone(6), 1,2,5-trihydroxy-6,8-dimethoxyxanthone(7), securixanthone G(8), gentisein(9), 3,7-dihydroxy-1-methoxyxanthone(10), pancixanthone B(11), garcimangosxanthone A(12), pruniflorone L(13), 9-hydroxy alabaxanthone(14), cochinchinone A(15), luteolin(16), 3,5'-dimethoxy-4',7-epoxy-8,3'-neolignane-5,9,9'-triol(17), N-benzyl-9-oxo-10E,12E-octadecadienamide(18), 15-hydroxy-7,13E-labdadiene(19), stigmasta-4,22-dien-3-one(20), and stigmast-5-en-3β-ol(21). Among these isolates, compound 1 was a new xanthone, compounds 2-5, 7, 8, 12, and 16-21 were isolated from the Cratoxylum plant for the first time, and compounds 11 and 13 were obtained from C. cochinchinense for the first time. Furthermore, all isolated compounds 1-21 were appraised for their anti-rheumatoid arthritis activities by MTS method through measuring their anti-proliferative effect on synoviocytes in vitro. As a result, xanthones 1-15 displayed notable anti-rheumatoid arthritis activities, which showed inhibitory effects on the proliferation of MH7A synoviocytes with the IC_(50) values ranging from(8.98±0.12) to(228.68±0.32) μmol·L~(-1).

Chromatographic profile of xanthones and flavonoids in the anti-dengue extracts of Fridericia samydoides (Cham. ) L. G. Lohmann (Bignoniaceae)

Abstract The flavonoids and xanthones present in the ethanol extracts of leaves and stems of Fridericia samydoides showed that anti-dengue activities in vitro were investigated qualitatively by liquid chromatography-ultraviolet-mass spectrometry in series. Nineteen flavones and fifteen xanthones were detected and characterized on the basis of their fragmentation pattern in the positive and negative ion mode tandem mass spectrometry spectra and ultraviolet bands. Acacetin, chrysin, vitexin, isovitexin, orientin, isoorientin, mangiferin, 2'-O-trans-caffeoylmangiferin, 2'-O-trans-coumaroylmangiferin and 2'-O-trans-cinnamoylmangiferin were identified by comparison with authentic samples. The other compounds detected were tentatively assigned by analysis of the spectral data and by comparison with literature reports. In addition, it performed the fractionation of the leaves extract leading to the isolation of mangiferin, isovitexin and isoorientin. All extracts and isolated compounds inhibited the Dengue virus replication cycle with EC50 less than 25.0 µg/mL for extracts and 272.5, 85.6 and 79.3 µg/mL for mangiferin, isovitexin and isoorientin, respectively.

Polycyclic polyprenylated acylphloroglucinols from Hypericum species and their biological activities / 中国中药杂志

Hypericum species are distributed widely in China, especially in the southwest. This genus is rich in species types in China, including 55 species and 8 subspecies. The main chemical constituents of Hypericum species are flavonoids, xanthones and polycyclic polyprenylated acylphloroglucinols(PPAPs). PPAPs are characterized by polycyclic and branched-chain substitutions in their structures, which make their structure types diverse. Moreover, they have been found to have antitumor, antiviral, antibacterial, anti-inflammatory and other biological activities. This research classified and summarized 344 polycyclic polyprenylated acylphloroglucinols from Hypericum plants in order to provide a scientific basis for further development and utilization of PPAPs from the genus.

Mangiferin attenuates IL / 中南大学学报(医学版)

OBJECTIVES@#Chondrocyte apoptosis is an important process in the pathogenesis of osteoarthritis. Mangiferin exerts multiple pharmacological effects such as anti-inflammatory and anti-apoptosis. However, the role of mangiferin in chondrocyte apoptosis is not clear. In this study, we aimed to explore the role of mangiferin in IL-1β-induced chondrocyte apoptosis.@*METHODS@#ATDC5 cells were randomly divided into a control group, a IL-1β group, a MFN-L group, a MFN-M group, a MFN-H group and a MFN+LY294002 group. Cells in the control group were treated with IL-1β (10 ng/mL) for 24 h; cells in the MFN-L group, the MFN-M group and the MFN-H group were pretreated with 5, 10 and 20 μmol/L mangiferin for 1 h respectively, and then they were treated with IL-1β (10 ng/mL) for 24 h; cells in the MFN+LY294002 group were treated with LY294002 (25 μmol/L) for 1 h, then mangiferin (20 μmol/L) and IL-1β (10 ng/mL) for 1 h and 24 h, respectively. Cell viability was detected by CCK-8 assay and cell apoptosis was measured by flow cytometry. Colorimetric assay was conducted to measure the caspase-3 activity. The protein levels of Bcl-2, Bax, and phosphoinositide 3-kinase (PI3K)/Akt signaling pathway related proteins were detected by Western blotting.@*RESULTS@#Compared to the control group, cell viability was significantly decreased; cell apoptosis, caspase-3 activity and Bax protein expression were significantly increased; the protein levels of Bcl-2, p-PI3K, and p-Akt were significantly decreased in the IL-1β group (all @*CONCLUSIONS@#Mangiferin could attenuate IL-1β-induced apoptosis of the mice chondrocytes, which is mediated by the activation of PI3K/Akt signaling pathway.

Research on autophagy induced by two xanthone compounds in HepG2 cells / 中国中药杂志

To investigate the inhibitory effects of two xanthone compounds, 1-hydroxy-2,3,4,8-4 methoxy xanthone(here in after referred to as Fr15) and 1-hydroxy-2,3,4,6-4 methoxy xanthone(here in after referred to as Fr17), on the proliferation of hepatocellular carcinoma cells HepG2, and to further investigate their mechanism in combination with transcriptomics. Cell counting was used to detect the effects of two kinds of xanthone compounds Fr15 and Fr17(0, 0.03, 0.15, 0.3 mmoL·L~(-1)) on the proliferation of HepG2 cells; the effects of the two compounds Fr15 and Fr17 on HepG2 cell cycle were detected by flow cytometry; the changes of autophagosomes count in cells were observed under fluorescence microscope; the expression of autophagy marker proteins autophagy marker proteins SQSTM 1(p62) and microtubule associated protein 1 light chain 3 Ⅰ/Ⅱ(LC3 Ⅰ/Ⅱ) in the cells was detected by Western blot; the differentially expressed genes between the control group and the experimental group were analyzed by RNA-seq transcriptome sequencing; qRT-PCR was used to verify the differentially expressed genes in sequencing. The results showed that compounds Fr15 and Fr17 inhibited the proliferation of HepG2 cells with the increase of drug concentration and time. Flow cytometry showed that compounds Fr15 and Fr17 had little effect on HepG2 cell cycle. Fluorescence microscopy results showed that the number of autophagosomes in cells increased with the increase of drug concentration. Western blot showed that the expression of p62 protein was decreased and the expression of LC3-Ⅱ protein was significantly increased after drug addition. The results of RNA sequencing showed that 26 102 and 52 351 differentially expressed genes were obtained in Fr15 and Fr17 respectively. Analysis of KEGG showed that drug treatment had a great effect on autophagy pathway. qRT-PCR verified that 6 up-regulated genes were related to autophagy, and their trend was consis-tent with sequencing results, where all 6 genes showed an up-regulated trend. Two xanthone compounds Fr15 and Fr17 may inhibit proliferation of HepG2 cells by inducing autophagy.

Effect of Mangiferin on Proliferation of FLT3-ITD Mutation Positive Acute Myeloid Leukemia Cell MV4-11 and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of mangiferin on proliferation, apoptosis and cycle of FLT3-ITD mutation-positive acute myeloid leukemia cells and its mechanism.@*METHODS@#The effects of different concentration of mangiferin on proliferation of MV4-11 cells were detected by CCK8 method. Apoptosis, cell cycle and FLT3 transmembrane protein expression were detected by flow cytometry. FLT3 mRNA expression was detected by real-time fluorescent quantitative polymerase chain reaction (PCR) .@*RESULTS@#Mangiferin obviously inhibited MV4-11 proliferation in a concentration and time dependent manner (48 h，r=0.922；72 h，r=0.959；96 h，r=0.973). The ratio of G0/G1 phase in cell cycle increased with the enhancement of concentration of mangiferin in MV4-11 cells for 48 h, and the ratio of S phase decreased with enhasment of concentration. The increase of apoptosis was more obvious. The expression of FLT3 transmembrane protein significantly decreased after the actior of IC50 concentration of mangiferin in MV4-11 cells for 48 h. The results of qRT-PCR showed that the expression of FLT3 mRNA significantly decreased after treatment of MN4-11 cells with mangiferin (P＜0.05).@*CONCLUSION@#Mangiferin inhibits MV4-11 cell proliferation, arrests cell cycle progression and promotes apoptosis, which may be related with the inhibition of FLT3 activity by mangiferin and the subsequent signaling pathways involved in apoptosis and proliferation of cells.

Protocol and Rationale: A 24-week Double-blind, Randomized, Placebo Controlled Trial of the Efficacy of Adjunctive Garcinia mangostana Linn. (Mangosteen) Pericarp for Schizophrenia

OBJECTIVE: Garcinia mangostana Linn., commonly known as mangosteen, is a tropical fruit with a thick pericarp rind containing bioactive compounds that may be beneficial as an adjunctive treatment for schizophrenia. The biological underpinnings of schizophrenia are believed to involve altered neurotransmission, inflammation, redox systems, mitochondrial dysfunction, and neurogenesis. Mangosteen pericarp contains xanthones which may target these biological pathways and improve symptoms; this is supported by preclinical evidence. Here we outline the protocol for a double-blind randomized placebo-controlled trial evaluating the efficacy of adjunctive mangosteen pericarp (1,000 mg/day), compared to placebo, in the treatment of schizophrenia. METHODS: We aim to recruit 150 participants across two sites (Geelong and Brisbane). Participants diagnosed with schizophrenia or schizoaffective disorder will be randomized to receive 24 weeks of either adjunctive 1,000 mg/day of mangosteen pericarp or matched placebo, in addition to their usual treatment. The primary outcome measure is mean change in the Positive and Negative Symptom Scale (total score) over the 24 weeks. Secondary outcomes include positive and negative symptoms, general psychopathology, clinical global severity and improvement, depressive symptoms, life satisfaction, functioning, participants reported overall improvement, substance use, cognition, safety and biological data. A 4-week post treatment interview at week 28 will explore post-discontinuations effects. RESULTS: Ethical and governance approvals were gained and the trial commenced. CONCLUSION: A positive finding in this study has the potential to provide a new adjunctive treatment option for people with schizophrenia and schizoaffective disorder. It may also lead to a greater understanding of the pathophysiology of the disorder.

Antioxidant xanthones and anthraquinones isolated from a marine-derived fungus Aspergillus versicolor / 中国天然药物

Chemical examination of an EtOAc extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones, eight anthraquinones and five alkaloids, including a new xanthone, oxisterigmatocystin D (1) and a new alkaloid, aspergillusine A (13). High resolution electron impact mass spectrometry (HR-EI-MS), FT-IR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds, and the absolute configuration of compound 1 was established by its NMR features and coupling constant. Furthermore, the biosynthesis pathway of these xanthones and anthraquinones were deduced, and their antioxidant activity and cytotoxicity in human cancer cell lines (HTC-8, Bel-7420, BGC-823, A549, and A2780) were evaluated. The trolox equivalent antioxidant capacity (TEAC) assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities. The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6, 7, 9, and 12 potentially activated the expression of Nrf2-regulated gene. In addition, compounds 5 and 11 showed weak cytotoxicity on A with the IC values of 25.97 and 25.60 μmol·L, respectively.

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells / 中国天然药物

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

Antioxidant xanthones and anthraquinones isolated from a marine-derived fungus Aspergillus versicolor / 中国天然药物

Chemical examination of an EtOAc extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones, eight anthraquinones and five alkaloids, including a new xanthone, oxisterigmatocystin D (1) and a new alkaloid, aspergillusine A (13). High resolution electron impact mass spectrometry (HR-EI-MS), FT-IR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds, and the absolute configuration of compound 1 was established by its NMR features and coupling constant. Furthermore, the biosynthesis pathway of these xanthones and anthraquinones were deduced, and their antioxidant activity and cytotoxicity in human cancer cell lines (HTC-8, Bel-7420, BGC-823, A549, and A2780) were evaluated. The trolox equivalent antioxidant capacity (TEAC) assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities. The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6, 7, 9, and 12 potentially activated the expression of Nrf2-regulated gene. In addition, compounds 5 and 11 showed weak cytotoxicity on A with the IC values of 25.97 and 25.60 μmol·L, respectively.

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells / 中国天然药物

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

Garcinexanthone G, a Selective Butyrylcholinesterase Inhibitor from the Stem Bark of Garcinia atroviridis

The present study was undertaken to investigate the isolated compounds from the stem bark of Garcinia atroviridis as potential cholinesterase inhibitors and the ligand-enzyme interactions of selected bioactive compounds in silico. The in vitro cholinesterase results showed that quercetin (3) was the most active AChE inhibitor (12.65 ± 1.57 µg/ml) while garcinexanthone G (6) was the most active BChE inhibitor (18.86 ± 2.41 µg/ml). It is noteworthy to note that compound 6 was a selective inhibitor with the selectivity index of 11.82. Molecular insight from docking interaction further substantiate that orientation of compound 6 in the catalytic site which enhanced its binding affinity as compared to other xanthones. The nature of protein-ligand interactions of compound 6 is mainly hydrogen bonding, and the hydroxyl group of compound 6 at C-10 is vital in BChE inhibition activity. Therefore, compound 6 is a notable lead for further drug design and development of BChE selective inhibitor.

Alpha-mangostin attenuates focal segmental glomerulosclerosis of mice induced by adriamycin / 中南大学学报(医学版)

To observe the protective effect of alpha-mangostin (α-MG) on focal segmental glomurular sclerosis (FSGS) induced by adriamycin.
 Methods: Adriamycin nephropathy (AN) model was induced by adriamycin (10 mg/kg) via a tail vein. Then the mice were treated with α-MG (12.5 mg/kg) or normal salin once daily for 6 weeks. At the end of 6 weeks, the mice were sacrificed, and the kidneys and blood samples were collected. Histopathology of the kidneys were analyzed under the optical microscope. The serum levels of biochemical indicators, such as serum creatinine (SCr), blood urea nitrogen (BUN) and cholesterol were determined. The levels of superoxide anion, malondialdehyde (MDA), and glutathione (GSH), the activity of superoxide dismutase (SOD) and catalase (CAT) in kidney tissues were determined. Serum levels of IL-1β, IL-18, IL-10 and adiponectin were determined. The levels of TGF-β1, collagen I (Col I), α-SMA, silent information regulator 1 (Sirt1) and the nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) in kidney tissues were determined using immunohistochemical staining, Western blot, and RT-PCR.
 Results: The levels of SCr, proteinuria, urine protein to creatinine ratio and serum cholesterol were attenuated in AN mice after α-MG treatment, while creatinine clearance rate and serum albumin were upregulated (P<0.05). α-MG treatment alleviated the glomerular and interstitial fibrosis, downregulated the expression of fibrosis markers, such as Col I and α-SMA (P<0.05). α-MG treatment reduced the production of superoxide anion, the levels of MDA and GSH, and increased the activity of CAT and SOD (P<0.05). α-MG treatment inhibitd the generation of pro-inflammatory cytokines, such as IL-1β and IL-18 and promoted the production of anti-inflammatory cytokines, such as the IL-10 and adiponectin (P<0.05); α-MG treatment promoted the expression of Sirt1, inhibitd the expression of NLRP3 in kidney tissues (P<0.05).
 Conclusion: α-MG could attenuates FSGS of mice induced by adriamycin ameliorate and improve renal function. α-MG exerts its anti-inflammatory and anti-oxidative effects by up-regulation the expression of Sirt1 and suppression of NLRP3.

Pharmacology of mangostins and their derivatives: A comprehensive review / 中国天然药物

Mangosteen (Garcinia mangostana Linn.) is a well-known tropical tree indigenous to Southeast Asia. Its fruit's pericarp abounds with a class of isoprenylated xanthones which are referred as mangostins. Numerous in vitro and in vivo studies have shown that mangostins and their derivatives possess diverse pharmacological activities, such as antibacterial, antifungal, antimalarial, anticarcinogenic, antiatherogenic activities as well as neuroprotective properties in Alzheimer's disease (AD). This review article provides a comprehensive review of the pharmacological activities of mangostins and their derivatives to reveal their promising utilities in the treatment of certain important diseases, mainly focusing on the discussions of the underlying molecular targets/pathways, modes of action, and relevant structure-activity relationships (SARs). Meanwhile, the pharmacokinetics (PK) profile and recent toxicological studies of mangostins are also described for further druggability exploration in the future.

Effects of ethanol extract of Bombax ceiba leaves and its main constituent mangiferin on diabetic nephropathy in mice / 中国天然药物

The present study was designed to explore the mechanism by which ethanol extract of Bombax ceiba leaves (BCE) and its main constituent mangiferin (MGF) affect diabetic nephropathy by combating oxidative stress. Oral administration of BCE and MGF to normal and streptozotocin (STZ)-induced diabetic mice were carried out. Fasting blood glucose, 24-h urinary albumin, serum creatinine, and blood urea nitrogen were tested, histopathology, and immunohistochemical analysis of kidney tissues were performed. Moreover, mesangial cells were treated with BCE and MGF for 48 h with or without 25 mmol·L of glucose. Immunofluorescence, Western blot and apoptosis analyses were used to investigate their regulation of oxidative stress and mitochondrial function. BCE and MGF ameliorated biochemical parameters and restored STZ-induced renal injury in the model mice. In vitro study showed that high glucose stimulation increased oxidative stress and cell apoptosis in mesangial cells. BCE and MGF limited mitochondrial membrane potential (Δψm) collapse by inhibiting Nox4, mitochondrially bound hexokinase II dissociation, and subsequent ROS production, which effectively reduced oxidative stress, cleaved caspase-3 expression and cell apoptosis. Our work indicated that BCE and MGF had protective effects on diabetic caused kidney injury and prevented oxidative stress in mesangial cells by regulation of hexokinase II binding and Nox4 oxidase signaling.

Mangiferin ameliorates insulin resistance by inhibiting inflammation and regulatiing adipokine expression in adipocytes under hypoxic condition / 中国天然药物

Adipose tissue hypoxia has been recognized as the initiation of insulin resistance syndromes. The aim of the present study was to investigate the effects of mangiferin on the insulin signaling pathway and explore whether mangiferin could ameliorate insulin resistance caused by hypoxia in adipose tissue. Differentiated 3T3-L1 adipocytes were incubated under normal and hypoxic conditions, respectively. Protein expressions were analyzed by Western blotting. Inflammatory cytokines and HIF-1-dependent genes were tested by ELISA and q-PCR, respectively. The glucose uptake was detected by fluorescence microscopy. HIF-1α was abundantly expressed during 8 h of hypoxic incubation. Inflammatory reaction was activated by up-regulated NF-κB phosphorylation and released cytokines like IL-6 and TNF-α. Glucose uptake was inhibited and insulin signaling pathway was damaged as well. Mangiferin substantially inhibited the expression of HIF-1α. Lactate acid and lipolysis, products released by glycometabolism and lipolysis, were also inhibited. The expression of inflammatory cytokines was significantly reduced and the damaged insulin signaling pathway was restored to proper functional level. The glucose uptake of hypoxic adipocytes was promoted and the dysfunction of adipocytes was relieved. These results showed that mangiferin could not only improve the damaged insulin signaling pathway in hypoxic adipocytes, but also ameliorate inflammatory reaction and insulin resistance caused by hypoxia.

Media of rat macrophage NR8383 cells with prostaglandins E2-induced VEGF over-expression promotes migration and tube formation of human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of prostaglandins E2 (PGE2) in enhancing vascular endothelial growth factor (VEGF) expression in a rat macrophage cell line and the effect of the media from PGE2-inuced rat macrophages on angiogenetic ability of human umbilical vein endothelial cells (HUVECs) in vitro.</p><p><b>METHODS</b>Western blotting and qPCR were employed to investigate the expressions of VEGF protein and mRNAs in rat macrophage cell line NR8383 stimulated by PGE2 in the presence or absence of EP2 receptor inhibitor (AH6809) and EP4 receptor inhibitor (AH23848). Conditioned supernatants were obtained from different NR8383 subsets to stimulate HUVECs, and the tube formation ability and migration of the HUVECs were assessed with Transwell assay.</p><p><b>RESULTS</b>PGE2 stimulation significantly enhanced the expression of VEGF protein and mRNAs in NR8383 cells in a dose-dependent manner. The supernatants from NR8383 cells stimulated by PGE2 significantly enhanced tube formation ability of HUVECs (P<0.05) and promoted the cell migration. Such effects of PGE2 were blocked by the application of AH6809 and AH23848.</p><p><b>CONCLUSION</b>PGE2 can dose-dependently increase VEGF expression in NR8383 cells, and the supernatants derived from PGE2-stimulated NR8383 cells can induce HUVEC migration and accelerate the growth of tube like structures. PGE2 are essential to corpus luteum formation by stimulating macrophages to induce angiogenesis through EP2/EP4.</p>

Activation of endogenous angiotensin converting enzyme 2 prevents early injuries induced by hyperglycemia in rat retina

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus that may result in blindness. We evaluated the effects of activation of endogenous angiotensin converting enzyme (ACE) 2 on the early stages of DR. Rats were administered an intravenous injection of streptozotocin to induce hyperglycemia. The ACE2 activator 1-[[2-(dimethylamino) ethyl] amino]-4-(hydroxymethyl)-7-[[(4-methylphenyl) sulfonyl] oxy]-9H-xanthone 9 (XNT) was administered by daily gavage. The death of retinal ganglion cells (RGC) was evaluated in histological sections, and retinal ACE2, caspase-3, and vascular endothelial growth factor (VEGF) expressions were analyzed by immunohistochemistry. XNT treatment increased ACE2 expression in retinas of hyperglycemic (HG) rats (control: 13.81±2.71 area%; HG: 14.29±4.30 area%; HG+XNT: 26.87±1.86 area%; P<0.05). Importantly, ACE2 activation significantly increased the RCG number in comparison with HG animals (control: 553.5±14.29; HG: 530.8±10.3 cells; HG+XNT: 575.3±16.5 cells; P<0.05). This effect was accompanied by a reduction in the expression of caspase-3 in RGC of the HG+XNT group when compared with untreated HG rats (control: 18.74±1.59; HG: 38.39±3.39 area%; HG+XNT: 27.83±2.80 area%; P<0.05). Treatment with XNT did not alter the VEGF expression in HG animals (P>0.05). Altogether, these findings indicate that activation of ACE2 reduced the death of retinal ganglion cells by apoptosis in HG rats.