Cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001 (B) Human PBMCs (105 cells/well) were 80-49-9 biological activity treated with the indicated concentrations of oenothein B in cRPMI medium for 48 hrs. CD69 expression on lymphocytes, which included CD3+ T cells, CD8+ T cells, cd T cells, and NK cells, was then measured by flow cytometry. The graphs represent pooled data from 5 individuals. 
Each treatment was analyzed in triplicate and error bars indicate SEM. Significance compared to untreated cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001. doi:10.1371/journal.pone.0050546.gStimulation of Lymphocytes by Oenothein BFigure 2. Oenothein B induces CD25 on human T cells. Human PBMCs (105 cells/well) were treated with the indicated concentrations of oenothein B in X-VIVO medium for 42 hrs. CD25 expression on lymphocytes, which included cd T cells (CD3+/cd TCR+), NK cells (CD32/CD56+), and ab T cells (CD3+/cd TCR-), was then measured by flow cytometry. The graph represents pooled data from 5 individuals. Each treatment was analyzed in duplicate and error bars indicate SEM. Significance compared to untreated cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001. doi:10.1371/journal.pone.0050546.gIsolation of Oenothein BOenothein B was isolated and identified as described previously [7]. Briefly, fully blossomed E. angustifolium were collected and the dried plant material (400g) was extracted with 80 methanol at room temperature for 3 days. The combined extracts were concentrated, and any precipitates were removed by filtration through a 0.22-mm filter. The filtrate was lyophilized to obtain the crude extract or subjected to concentration and fractionation 23115181 on a Sephadex LH-20 column 
(2.8 6 33 cm) using 80 methanol as an eluent. The relevant fractions were pooled and evaporated to dryness, re-chromatographed twice, and compound identification was performed by NMR and mass spectrometry, as described [7]. Purity was determined to be .95 by HPLC and mass spectrometry, as described [7]. A Limulus amebocyte lysate assay kit (Cambrex, East Rutherford, NJ) was used to evaluate possible endotoxin contamination in purified oenothein B. Purified oenothein B found to be free of endotoxin was stored at -80uC until used in the functional assays described below.Human and Bovine Peripheral Blood Mononuclear Cell PreparationsWhole blood was collected from 1- to 3-month bull Holstein 1326631 calves into sodium heparin tubes (BD Biosciences, San Jose, CA) and from healthy human adult donors with ACD solution B anticoagulant tubes (BD Biosciences). Mononuclear cells were separated from whole blood using Histopaque 1077 (SigmaAldrich, St. Louis, MO) or Ficoll-PaqueTMPremium (GE Healthcare, Piscataway, NJ) for bovine and human cells, respectively, as previously described [4] and per the manufacturer’s MedChemExpress ML 281 instructions. Additionally, bovine red blood cells were removed by hypotonic lysis after Histopaque separation.Figure 3. Oenothein B primes bovine PBMCs to respond to IL18. Bovine PBMCs (105 cells/well) were treated with oenothein B (40 mg/ml and 20 mg/ml), EGCG (40 mg/ml and 20 mg/ml), resveratrol (50 mg/ml and 25 mg/ml), curcumin (40 mg/ml and 20 mg/ml), theaflavin digallate (50 mg/ml), or X-VIVO medium alone for approximately 24 hrs. Cells were then washed and treated with 10 ng/ml rhu IL-18, 100 ng/ml rhu IL-18, or X-VIVO medium alone fo.Cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001 (B) Human PBMCs (105 cells/well) were treated with the indicated concentrations of oenothein B in cRPMI medium for 48 hrs. CD69 expression on lymphocytes, which included CD3+ T cells, CD8+ T cells, cd T cells, and NK cells, was then measured by flow cytometry. The graphs represent pooled data from 5 individuals. Each treatment was analyzed in triplicate and error bars indicate SEM. Significance compared to untreated cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001. doi:10.1371/journal.pone.0050546.gStimulation of Lymphocytes by Oenothein BFigure 2. Oenothein B induces CD25 on human T cells. Human PBMCs (105 cells/well) were treated with the indicated concentrations of oenothein B in X-VIVO medium for 42 hrs. CD25 expression on lymphocytes, which included cd T cells (CD3+/cd TCR+), NK cells (CD32/CD56+), and ab T cells (CD3+/cd TCR-), was then measured by flow cytometry. The graph represents pooled data from 5 individuals. Each treatment was analyzed in duplicate and error bars indicate SEM. Significance compared to untreated cells (0 mg/ml) was determined by One-way ANOVA with Bonferroni post-test. *p,0.05, **p,0.01, ***p,0.001. doi:10.1371/journal.pone.0050546.gIsolation of Oenothein BOenothein B was isolated and identified as described previously [7]. Briefly, fully blossomed E. angustifolium were collected and the dried plant material (400g) was extracted with 80 methanol at room temperature for 3 days. The combined extracts were concentrated, and any precipitates were removed by filtration through a 0.22-mm filter. The filtrate was lyophilized to obtain the crude extract or subjected to concentration and fractionation 23115181 on a Sephadex LH-20 column (2.8 6 33 cm) using 80 methanol as an eluent. The relevant fractions were pooled and evaporated to dryness, re-chromatographed twice, and compound identification was performed by NMR and mass spectrometry, as described [7]. Purity was determined to be .95 by HPLC and mass spectrometry, as described [7]. A Limulus amebocyte lysate assay kit (Cambrex, East Rutherford, NJ) was used to evaluate possible endotoxin contamination in purified oenothein B. Purified oenothein B found to be free of endotoxin was stored at -80uC until used in the functional assays described below.Human and Bovine Peripheral Blood Mononuclear Cell PreparationsWhole blood was collected from 1- to 3-month bull Holstein 1326631 calves into sodium heparin tubes (BD Biosciences, San Jose, CA) and from healthy human adult donors with ACD solution B anticoagulant tubes (BD Biosciences). Mononuclear cells were separated from whole blood using Histopaque 1077 (SigmaAldrich, St. Louis, MO) or Ficoll-PaqueTMPremium (GE Healthcare, Piscataway, NJ) for bovine and human cells, respectively, as previously described [4] and per the manufacturer’s instructions. Additionally, bovine red blood cells were removed by hypotonic lysis after Histopaque separation.Figure 3. Oenothein B primes bovine PBMCs to respond to IL18. Bovine PBMCs (105 cells/well) were treated with oenothein B (40 mg/ml and 20 mg/ml), EGCG (40 mg/ml and 20 mg/ml), resveratrol (50 mg/ml and 25 mg/ml), curcumin (40 mg/ml and 20 mg/ml), theaflavin digallate (50 mg/ml), or X-VIVO medium alone for approximately 24 hrs. Cells were then washed and treated with 10 ng/ml rhu IL-18, 100 ng/ml rhu IL-18, or X-VIVO medium alone fo.