Additional file 1: Table S1. of No increase in small-solute transport in peritoneal dialysis patients treated without hypertonic glucose for fifty-four months

Covariance parameters derived from the linear mixed model fitted on the whole data from inclusion to end of follow-up (PDF 180 kb

Contribution of genetic background to oxidative stress resistance induced by açaí aqueous extract (AAE) treatment.

<p>Animals were treated with 100/mL AAE or control solution (S basal) from L1 until L4 and then submitted to 7.5 mM t-BOOH in M9. Survival was measured at 3, 6, 9 and 12 h. <b>A</b>) Survival curves for transcription factor <i>daf-16 (mu86)</i> and JNK MAPK pathway <i>jnk-(gk7)</i> mutants. <b>B</b>) Survival curves for <i>skn-1(zu67)</i> and p38 MAPK pathway, <i>nsy-1(ag3)</i>, <i>sek-1(km4)</i> mutants. <b>C</b>) Survival curves for osmotic stress resistance pathway, <i>unc-43(n498n1186)</i> and <i>osr-1(rm1)</i> mutants. *p<0.05 and ***p<0.001 by the Log-rank (Mantel-Cox) test (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089933#pone-0089933-t003" target="_blank">Table 3</a> for more details).</p

Effect of açaí aqueous extract (AAE) on redox status in wild-type <i>C. elegans</i> and HUVECs.

<p><b>A</b>) <i>C. elegans</i> was treated with control solution (S basal) or 100 mg/mL AAE for 48 h and then submitted to the presence or absence of 1 mM H₂O₂ for 2 h. The results are expressed as H₂DCFDA fluorescence relative to the untreated control. <b>B</b>) HUVECs were treated with or without 2.5 mg/mL AAE for 16 h and then incubated in 0.25 mM H₂O₂ for 1 h. The fluorescence was measured by flow cytometry. The results are expressed as H₂DCFDA fluorescence relative to the untreated control. Different letters indicate significant differences by one-way ANOVA followed by Tukey's post-test. <b>C</b>) To measure the levels of total SH groups, animals were treated with control solution (S basal) or 100 mg/mL AAE from L1 until L4 and then incubated with or without 5 mM t-BOOH for 1 h. *p values were determined by a two-tailed Student's <i>t-</i>test, and groups were significantly different when p<0.05 in <i>C. elegans</i>. Transgenic worms containing reporter genes were treated with control solution (S basal) or 100 mg/mL AAE for 48 h beginning at L1 and then with or without the oxidative stress condition. After a 1-h hour recovery period, photographs were taken on a fluorescence microscope. For (<b>D</b>) <i>gcs-1::GFP</i> and (<b>E</b>) <i>gst-4::GFP</i> animals, GFP fluorescence signals were measured using NIH Image J software. Different letters correspond to significant differences by the Kruskal-Wallis test followed by Dunn's post-test.</p

Effect of açaí aqueous extract (AAE) on <i>C. elegans</i> grown under normal and stress conditions.

<p><b>A</b>) <i>fem-1(hc17)</i> mutants were treated at 25°C with control solution (S basal) or 100 mg/mL AAE beginning at L1. Surviving and dead animals were counted daily until all nematodes had died. Log-rank (Mantel-Cox) analysis showed no significant difference between the curves. <b>B</b>) Animals were treated with control solution (S basal) or 100 mg/mL AAE from L1 until L4 and then submitted to 7.5 mM t-BOOH in M9. The survival was measured at 6, 9 and 12 h. The survival curves show that AAE treatment increased <i>C. elegans</i> oxidative stress resistance. ***p<0.001 by the Log-rank (Mantel-Cox) test. <b>C</b>) Animals were treated with control solution (S basal) or 100 mg/mL AAE beginning at L1. After five days at 20°C, the animals were incubated at 35°C and survival was monitored at 6, 9 and 12 h. There was no significant difference between curves by the Log-rank (Mantel-Cox) test. <b>D</b>) Animals were treated with control solution (S basal) or 100 mg/mL AAE for 68 h beginning at L1 and then transferred to new plates containing 500 mM NaCl. The percentage of worms that moved outside a 7-mm circle was monitored at 15, 30 and 60 min. *p<0.05 by a two-tailed Student's <i>t-</i>test.</p

<i>In vitro</i> antioxidant activity of açaí aqueous extract (AAE) measured by DPPH assay.

<p>DPPH, 2,2-diphenyl-1-picrylhydrazyl; Trolox, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; OP50, <i>E. coli</i> strain; KAN, Kanamycin.</p><p>Different subscript letters indicate significant differences by one-way ANOVA followed by Tukey's post-test.</p

Effect of açaí aqueous extract (AAE) on wild-type <i>C. elegans</i> body length and progeny.

<p><b>A</b>). L1 animals were treated with control solution (S basal) or 100 mg/mL AAE until L3 and then transferred onto NGM plates with OP50 until the next day. Images were captured of one-day-old animals, and body length was measured along the animal axis using NIH Image J software. There was no significant difference between groups, as determined by two-tailed Student's <i>t-</i>test. <b>B, C</b>) Progeny profiles were measured in animals treated with control solution (S basal) or 100 mg/mL AAE. Animals were transferred individually to NGM plates and moved daily until the end of the reproductive period. The results were plotted as the mean ± SEM for each day (B) and total final progeny (C). There was no significant difference between groups by a two-tailed Student's <i>t-</i>test.</p

Hypothetical model of the mode of action of açaí aqueous extract (AAE) on <i>C. elegans</i>.

<p>Text marked within a rectangle represents modulators or data observed experimentally in this manuscript. AAE modulates oxidative stress resistance by direct and indirect mechanisms. AAE removes ROS directly and prevents <i>gcs-1</i> activation and SH level reduction which in turn increases oxidative stress resistance. AAE also promotes oxidative stress resistance indirectly through DAF-16/OSR-1/UNC-43/SEK-1. In addition, AAE increases osmotic stress resistance, possibly as a result of impaired protein homeostasis and/or increased ionic strength.</p

Effect of açaí aqueous extract (AAE) on the bacterial growth and oxidative stress resistance of wild-type <i>C. elegans</i> grown on dead bacteria.

<p><b>A</b>) <i>E. coli</i> OP50 growth was evaluated over 4 h in the presence of 100 mg/mL AAE. The OD of the control group at time zero was used to normalize all other OD readings. * Treatment of 100 mg/mL AAE decreased bacteria growth at all times analyzed with p<0.05, determined by a two-tailed Student's <i>t-</i>test. <b>B</b>) Animals were treated with or without 100 mg/mL AAE, mixed with either <i>E. coli</i> OP50 or <i>E. coli</i> OP50 treated with 10 mM Kanamycin (KAN), from L1 until L4 and then submitted to 7.5 mM t-BOOH in M9. The survival was measured at 6, 9 and 12 h. The survival curves show that AAE treatment increased <i>C. elegans</i> oxidative stress resistance independent of its antibacterial effect. ***p<0.001 related to the respective control by the Log-rank (Mantel-Cox) test.</p

Effect of açaí aqueous extract (AAE) on protein homeostasis.

<p><b>A</b>) mRNA level of <i>osr-1</i> in wild-type animals treated or not with 100 mg/mL AAE for 48 h. <b>B</b>) Transgenic worms carrying the reporter gene <i>gpdh-1::GFP</i> were treated or not with 100 mg/mL AAE for 48 h and then photographs were taken on a fluorescent microscope. GFP fluorescence signals were measured using NIH Image J software. ***p<0.001 by a two-tailed Student's <i>t-</i>test. <b>C</b>) Transgenic worms carrying the reporter gene <i>vha-6::Q44::YFP</i> were treated with control solution (S basal) or 100 mg/mL AAE starting at L1. Photographs of one-, four-, eight- and twelve-day-old animals were taken on a fluorescence microscope, and the numbers of aggregates were counted. *p<0.05 by a one-tailed Student's <i>t-</i>test. <b>D</b>) Animals were treated with 100 mg/mL AAE or control solution (S basal) from L1 until L4. Proteasome chymotrypsin-like activity was monitored by SLLVY-MCA digestion in L4 worm extracts containing equal amounts of total protein. ***p<0.001 by a two-tailed Student's <i>t-</i>test.</p

Determination of anthocyanins present in açaí aqueous extract (AAE).

<p>The results are expressed as the mean ± SEM (standard error of the mean).</p>a<p>Total monomeric anthocyanins measured by the pH differential method.</p>b<p>Cyanidin 3-O glucoside and Cyanidin 3-O rutinoside determined by LC-MS/MS analysis.</p