Author Correction: Cyclocarya paliurus tea leaves enhances pancreatic ß cell preservation through inhibition of apoptosis.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cyclocarya paliurus tea leaves enhances pancreatic ß cell preservation through inhibition of apoptosis.

Leaves of Cyclocarya paliurus are a sweet tea traditionally used to treat obesity and diabetes in China. However, its protective mechanisms against hyperglycemia remains unclear. Here, we demonstrate that the extract of C. paliurus leaves significantly decreased body loss, food intake and blood glucose level, and increased blood insulin level, ß-cell number and insulin-producing ß cells in high-fat diet-low dose STZ-induced diabetic mice. In vivo and in vitro studies also showed the extract of C. paliurus leaves significantly inhibited pancreatic ß cell apoptosis by suppressing the expression of caspase 8, caspase 9 and cleaved caspase-3, as well as Bax/Bcl-2 ratio, down-regulating p38, ERK and JNK phosphorylation, and up-regulating Akt phosphorylation. These effects were significantly enhanced by inhibitor p-38 or ERK or JNK, and counteracted by inhibitor of PI3K. In addition, the extract of C. paliurus leaves also significantly improved hepatic steatosis, nephropathy and cardiac hypertrophy of diabetic mice. Taken together, these results provide the insight into the effects of C. paliurus leaves on pancreatic ß cell preservation in standing glucolipotoxicity. Therefore, C. paliurus tea leaves may be used as a new remedy for diabetes through enhancing pancreatic ß cell preservation by inhibiting ß cell apoptosis.

Magnolol, a Natural Polyphenol, Attenuates Dextran Sulfate Sodium-Induced Colitis in Mice.

Magnolol is a lignan with anti-inflammatory activity identified in Magnolia officinalis. Ulcerative colitis (UC), one of the types of inflammatory bowel disease (IBD), is a disease that causes inflammation and ulcers in the colon. To investigate the effect of magnolol in dextran sulfate sodium (DSS)-induced experimental UC model, male C57 mice were treated with 2% DSS drinking water for 5 consecutive days followed by intragastric administration with magnolol (5, 10 and 15 mg/kg) daily for 7 days. The results showed that magnolol significantly attenuated disease activity index, inhibited colonic shortening, reduced colonic lesions and suppressed myeloperoxidase (MPO) activity. Moreover, colonic pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß) induced by colitis were dramatically decreased by magnolol. To further unveil the metabolic signatures upon magnolol treatment, mass spectrometry-based metabolomic analysis of the small molecular metabolites in mice serum were performed. Compared with controls, abnormality of serum metabolic phenotypes in DSS-treated mice were effectively reversed by different doses of magnolol. In particular, magnolol treatment effectively elevated the serum levels of tryptophan metabolites including kynurenic acid (KA), 5-hydroxyindoleacetic acid, indoleacetic acid (IAA), indolelactic acid and indoxylsulfuric acid, which are potential aryl hydrocarbon receptor (AHR) ligands to impact colitis. These findings suggest that magnolol exerts anti-inflammatory effect on DSS-induced colitis and its underlying mechanisms are associated with the restoring of tryptophan metabolites that inhibit the colonic inflammation.

Azoxystrobin Induces Apoptosis of Human Esophageal Squamous Cell Carcinoma KYSE-150 Cells through Triggering of the Mitochondrial Pathway.

Recent studies indicate that mitochondrial pathways of apoptosis are potential chemotherapeutic target for the treatment of esophageal cancer. Azoxystrobin (AZOX), a methoxyacrylate derived from the naturally occurring strobilurins, is a known fungicide acting as a ubiquinol oxidation (Qo) inhibitor of mitochondrial respiratory complex III. In this study, the effects of AZOX on human esophageal squamous cell carcinoma KYSE-150 cells were examined and the underlying mechanisms were investigated. AZOX exhibited inhibitory effects on the proliferation of KYSE-150 cells with inhibitory concentration 50% (IC50) of 2.42 µg/ml by 48 h treatment. Flow cytometry assessment revealed that the inhibitory effect of AZOX on KYSE-150 cell proliferation occurred with cell cycle arrest at S phase and increased cell apoptosis in time-dependent and dose-dependent manners. Cleaved poly ADP ribose polymerase (PARP), caspase-3 and caspase-9 were increased significantly by AZOX. It is worth noted that the Bcl-2/Bax ratios were decreased because of the down-regulated Bcl-2 and up-regulated Bax expression level. Meanwhile, the cytochrome c release was increased by AZOX in KYSE-150 cells. AZOX-induced cytochrome c expression and caspase-3 activation was significantly blocked by Bax Channel Blocker. Intragastric administration of AZOX effectively decreased the tumor size generated by subcutaneous inoculation of KYSE-150 cells in nude mice. Consistently, decreased Bcl-2 expression, increased cytochrome c and PARP level, and activated caspase-3 and caspase-9 were observed in the tumor samples. These results indicate that AZOX can effectively induce esophageal cancer cell apoptosis through the mitochondrial pathways of apoptosis, suggesting AZOX or its derivatives may be developed as potential chemotherapeutic agents for the treatment of esophageal cancer.

Halofuginone reduces the inflammatory responses of DSS-induced colitis through metabolic reprogramming.

Hypoxia and inflammation have been identified as the hallmarks of colitis, intertwined with metabolism. Here, we report that halofuginone (HF), an antiparasitic drug, attenuates dextran sulfate sodium (DSS)-induced colitis in mice, as represented by attenuating the disease activity index, inhibiting colonic shortening, ameliorating colonic lesions and histological signs of damage, reducing colonic myeloperoxidase activity, and suppressing the production of pro-inflammatory cytokines in colon tissue. Intriguingly, the hypoxia-inducible factor 1alpha (HIF-1α) and tumor necrosis factor alpha were also suppressed by HF treatment in colon tissues, exhibiting a tissue-specific effect. To further reveal the metabolic signatures upon HF treatment, mass spectrometry-based metabolomic analysis of the small molecular metabolites in liver, spleen and colon tissues was performed. As a result, we found that HF treatment counteracted the levels of acylcarnitines, including palmitoyl-l-carnitine, isobutyrylcarnitine, vaccenylcarnitine, and myristoylcarnitine, in colon tissues with DSS induction, but no significant change in the levels of acylcarnitines was observed in liver or spleen tissues. The metabolic signatures may indicate that incomplete fatty acid oxidation (FAO) in the colon could be restored upon HF treatment as the tissue-specific metabolic characterization. Taken together, our findings uncovered that the HF potentiated anti-inflammatory effect in DSS-induced colitis in mice and its underlying mechanisms could be associated with the inhibition of HIF-1α and reduced levels of acylcarnitines, suggesting that both the inhibition of HIF-1α and the counteraction of incomplete FAO might be useful in the prevention and treatment of inflammatory bowel disease.

Berberine ameliorates chronic relapsing dextran sulfate sodium-induced colitis in C57BL/6 mice by suppressing Th17 responses.

Ulcerative colitis (UC) is an increasingly common condition particularly in developed countries. The lack of satisfactory treatment has fueled the search for alternative therapeutic strategies. In recent studies, berberine, a plant alkaloid with a long history of medicinal use in Chinese medicine, has shown beneficial effects against animal models of acute UC. However, UC usually presents as a chronic condition with frequent relapse in patients. How berberine will act on chronic UC remains unclear. In the present study, we adopted dextran sulfate sodium (DSS)-induced chronic relapsing colitis model to assess the ameliorating activity of berberine. Colitis was induced by two cycles of 2.0% DSS for five days followed by 14days of drinking water plus a third cycle consisting of DSS only for five days. The colitis mice were orally administered 20mg/kg berberine from day 13 onward for 30days and monitored daily. The body weight, stool consistency, and stool bleeding were recorded for determination of the disease activity index (DAI). At the end of treatment, animals were sacrificed and samples were collected and subjected to histological, RT-qPCR, Western blot, and LC-MS analyses. Lymphocytes were isolated from spleens and mesenteric lymph nodes (MLN) and cultured for flow cytometry analysis of IL-17 secretion from CD4(+) cells and the Th17 cell differentiation. Results showed that berberine significantly ameliorated the DAI, colon shortening, colon tissue injury, and reduction of colonic expression of tight junction (TJ) protein ZO-1 and occludin of colitis mice. Notably, berberine treatment pronouncedly reduced DSS-upregulated Th17-related cytokine (IL-17 and ROR-γt) mRNAs in the colon. Furthermore, the mRNA expression of IL-6 and IL-23, and the phosphorylation of STAT3 in colon tissues from DSS-treated mice were pronouncedly inhibited by berberine. Moreover, the up-regulation of IL-17 secretion from CD4(+) cells of spleens and MLNs caused by DSS were significantly reversed by berberine treatment. Furthermore, Th17 cell differentiation from naive CD4(+) cells isolated from above DSS colitis mice were suppressed by berberine in a concentration-dependent manner. In summary, we demonstrated for the first time that berberine reduced the severity of chronic relapsing DSS-induced colitis by suppressing Th17 responses. The demonstration of activity in this mouse model supports the possibility of clinical efficacy of berberine in treating chronic UC.

A novel coumarin, (+)-3'-angeloxyloxy-4'-keto-3',4'-dihydroseselin, isolated from Bupleurum malconense (Chaihu) inhibited NF-κB activity.

BACKGROUND: This study aims to identify the major anti-inflammatory components in the petroleum ether extract of Bupleurum malconense (Chaihu), by bioassay-guided fractionation, and to investigate the anti-inflammatory mechanisms of active components in lipopolysaccharide (LPS)-stimulated murine macrophage RAW-Blue cells. METHODS: A QUANTI-Blue assay was used to guide fractionation of B. malconense root extract. The petroleum ether extract which exerted significant secreted embryonic alkaline phosphatase (SEAP) inhibition effect was purified by silica gel column chromatography and assisted with reverse phase HPLC. The major bioactive compound which significantly inhibited SEAP activity was obtained and its anti-inflammatory effects in LPS-induced RAW-Blue cells were measured by the overproduction of NO (Griess method), gene expression of Il-1ß, Tnf-α and iNos (real-time PCR). In parallel, protein expressions of COX-2, iNOS and IκB-α were determined by western blot. RESULTS: In bioassay-guided fractionation using LPS-stimulated mouse macrophage RAW-Blue cells, (+)-3'-angeloxyloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) was identified by MS and NMR spectral analyses. Pd-Ib (5, 10, 20 µg/mL) suppressed the gene expression of Il-1ß (P < 0.0001, P < 0.0001, P < 0.0001 for three respective concentrations), Tnf-α (P = 0.006, P = 0.001, P < 0.0001 for three respective concentrations) and iNos (P = 0.009, P < 0.0001, P < 0.0001 for three respective concentrations) in LPS-stimulated macrophages. The production of cyclooxygenase-2 (P = 0.019, P = 0.002, P < 0.0001), iNOS (P < 0.0001, P < 0.0001, P < 0.0001 for three respective concentrations) and NO (P < 0.0001, P < 0.0001, P < 0.0001 for three respective concentrations) significantly decreased when macrophages were treated with Pd-Ib (5, 10, 20 µg/mL) in the presence of LPS. Pd-Ib (5, 10, 20 µg/mL) suppressed the nuclear activation of NF-κB while it up-regulated the IκB-α level (P = 0.028, P = 0.013, P = 0.005 for three respective concentrations) in LPS-stimulated macrophages. CONCLUSIONS: Pd-Ib isolated from B. malconense suppressed LPS-induced inflammatory responses in macrophages by inhibiting NF-κB activity and reducing the expression of iNOS, COX-2 as well as pro-inflammatory cytokines.

Anti-inflammatory Actions of (+)-3'α-Angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) against Dextran Sulfate Sodium-Induced Colitis in C57BL/6 Mice.

The immunoregulatory protective properties of (+)-3'α-angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) isolated from Bupleurum malconense has not been reported. In the present study, the therapeutic effect of Pd-Ib (30, 60, and 120 mg/kg/day) was examined in a mouse model of dextran sulfate sodium (DSS)-induced acute colitis. Administration of Pd-Ib significantly reduced the disease activity index, inhibited the shortening of colon length, reduced colonic tissue damage, and suppressed colonic myeloperoxidase activity and nitric oxide levels in mice with DSS-induced colitis. Moreover, Pd-Ib greatly suppressed the secretion of pro-inflammatory cytokines TNF-α, IFN-γ, IL-6, and IL-17A while enhancing the level of anti-inflammatory cytokine IL-4. The protein levels of phosphorylated STAT3 (p-STAT3) and phosphorylated p38 (p-p38) were down-regulated in the colonic tissues of DSS-treated mice. Importantly, the anti-inflammatory effect of Pd-Ib against acute colitis was comparable to the anti-inflammatory sulfa drug sulfasalazine (300 mg/kg). Furthermore, the in vitro study showed that the inhibitory effect of Pd-Ib on p-STAT3 and IL-6 protein levels was accompanied by the reduction of MAPKs (JNK and p38). In conclusion, this study suggested that Pd-Ib attenuated DSS-induced acute colitis via the regulation of interleukins principally through the STAT3 and MAPK pathways.

Spexin Enhances Bowel Movement through Activating L-type Voltage-dependent Calcium Channel via Galanin Receptor 2 in Mice.

A novel neuropeptide spexin was found to be broadly expressed in various endocrine and nervous tissues while little is known about its functions. This study investigated the role of spexin in bowel movement and the underlying mechanisms. In functional constipation (FC) patients, serum spexin levels were significantly decreased. Consistently, in starved mice, the mRNA of spexin was significantly decreased in intestine and colon. Spexin injection increased the velocity of carbon powder propulsion in small intestine and decreased the glass beads expulsion time in distal colon in mice. Further, spexin dose-dependently stimulated the intestinal/colonic smooth muscle contraction. Galanin receptor 2 (GALR2) antagonist M871, but not Galanin receptor 3 (GALR3) antagonist SNAP37899, effectively suppressed the stimulatory effects of spexin on intestinal/colonic smooth muscle contraction, which could be eliminated by extracellular [Ca(2+)] removal and L-type voltage-dependent Ca(2+) channel (VDCC) inhibitor nifedipine. Besides, spexin dramatically increased the [Ca(2+)]i in isolated colonic smooth muscle cells. These data indicate that spexin can act on GALR2 receptor to regulate bowel motility by activating L-type VDCC. Our findings provide evidence for important physiological roles of spexin in GI functions. Selective action on spexin pathway might have therapeutic effects on GI diseases with motility disorders.

Dibenzocyclooctadiene lignans and norlignans from fruits of Schisandra wilsoniana.

Seven new dibenzocyclooctadiene lignans, marlignans M-S (1-7), four new norlignans, marphenols C-F (8-11), and 21 known compounds (12-32) were isolated from the fruits of Schisandra wilsoniana. The structures of 1-11 were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques and CD experiments. Compounds 1-11 were evaluated for their anti-HIV activities and showed EC(50) values in the range 2.97-6.18 µg/mL and therapeutic index values of 5.33-29.13.

Neolignans from Schisandra wilsoniana and their anti-human immunodeficiency virus-1 activities.

Four new neolignans, marphenols G-J (1-4), together with two known ones, were isolated from the leaves and stems of Schisandra wilsoniana. The structures of 1-4 were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. New compounds 1-4 were tested for their anti-human immunodeficiency virus (HIV)-1 activities and they showed weak bioactivities.

Secolignans, neolignans and phenylpropanoids from Daphne feddei and their biological activities.

Two new secolignans and one new neolignan, named feddeiphenols A-C (1-3), together with eight known compounds (4-11), were isolated from the leaves and stems of Daphne feddei. Their structures were established on the base of spectroscopic methods, mainly extensive NMR, UV spectroscopy, and MS spectrometry. Compounds 1-11 were tested for their anti-human immunodeficiency virus (HIV)-1 activity and cytotoxicity. The results revealed that compounds 1, 2, 3, 7, and 9 showed therapeutic index (TI) values above 30, respectively, and the other compounds also showed weak anti-HIV-1 activity. Compound 1 showed modest cytotoxic activity. The other compounds also showed weak cytotoxic activity.

Dibenzocyclooctadiene lignans from the fruits of Schisandra rubriflora and their anti-HIV-1 activities.

Two new dibenzocyclooctadiene lignans, rubrilignans A and B (1, 2), together with 17 known ones, were isolated from the fruits of Schisandra rubriflora. The structures of 1 and 2 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-HIV-1 activities and showed weak anti-HIV-1 activity with EC(50) values of 2.26 and 1.82 µg/ml, and therapeutic index values of 35.5 and 18.6, respectively.