Browsing by Subject "Quercetin"
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Item Conventional Breeding and Molecular Techniques to Improve Phytochemical Concentrations in Pepper (Capsicum spp.)(2012-02-14) Butcher, JustinFive separate field experiments were conducted across different environmental locations in Texas for the purpose of quantifying concentrations of different phytochemical groups (ascorbic acid, capsaicinoids, and flavonoids) within various pepper species, as well as, to identify the most optimum environment to promote expression of the aforementioned phytochemical. Depending on the particular experiment, quantitative measurements were then used in more detail in one of three ways: for identification of the most superior individuals and optimum environmental locations to express elevated concentrations of a particular phytochemical (first three experiments), to calculate heritability and % heterosis estimates for various fruit characteristics and phytochemical levels (fourth experiment), or for use in a specific biotechnology technique to potentially identify a molecular marker linked to elevated levels of ascorbic acid (AA) and flavonoids (quercetin and luteolin) (fifth experiment). In the first experiment, significant differences in fruit weight, capsaicin, and dihydrocapsaicin (DHC) were revealed in fruit tissue of five Habanero (Capsicum chinense) hybrids in comparison to a popular, commercial check (Kukulkan F1) after being grown across three different environmental locations (College Station, Uvalde, and Weslaco). Fruit grown at the Weslaco location was found to be larger and contained more capsaicin and DHC than those produced in Uvalde or College Station. While flavonoid contents were variable and low in all genotypes and locations, a few hybrids showed some potential for use in future crossing schemes to compete against the commercial check. Our results further suggested that variation in phytochemicals in fruit tissue of Habanero genotypes can be exploited by selecting in an appropriate environment. In the second experiment, analysis of four jalape?o hybrids in comparison to three commercial checks (Dragon, Ixtapa, and J1845), as well as, two cayenne hybrids in comparison to one commercial check (Mesilla) were compared after growing in three different locations (Amarillo, College Station, and Uvalde). Results demonstrated that the College Station location contributed to production of fruit containing higher concentrations of both AA and flavonoids, while those grown in Amarillo produced fruit with higher capsaicinoids. As expected, cayenne samples contained more AA and flavonoids than jalape?o samples. In comparison to the commercial jalape?o checks, all jalape?o hybrids generally expressed less capsaicinoids. With respect to AA and flavonoid concentrations, a few jalape?o hybrids proved to have some potential to compete against their respective commercial cultivars. For the cayenne market, one genotype revealed its potential use in mild markets and for farmers interested in a new hybrid expressing both appreciable levels of phytochemicals, as well as, more visually aesthetic attributes. Statistical analyses from the third experiment found all the F-values for each characteristic to be significant except the Location x Genotype (L x G) component for fruit wall thickness. For this experiment, a total of 21 different C. annuum (jalape?o, Serrano, and cayenne) genotypes were evaluated after growing in two diverse environmental locations (Uvalde and Weslaco). In general, peppers grown in Weslaco produced fruit with higher concentrations of AA and capsaicinoids, with a few exceptions, while fruit grown at Uvalde generally was larger in size and contained higher concentrations of flavonoids. In comparison to their respective commercial checks (jalape?o ? Dragon, Tormenta; Serrano ? Halcon, Magnum45; cayenne ? Mesilla), a few hybrids were arguably more desirable for their respective markets with respect to different fruit measurements, AA, capsaicinoid, and flavonoid concentrations. This evidence further suggested the potential benefit this material could have for growers interested in replacing current material in the industry and to more successfully provide consumers with a healthier ingredient to better sustain their lives. In the fourth experiment, results confirmed our hypotheses that paprika type material has higher AA and flavonoid concentrations than Serrano peppers, while the opposite is possible for capsaicinoid expression. For this experiment, our goal was to identify the relative ease of incorporating different traits of interest into an improved specimen evaluating a combination of 29 F1 paprika and Serrano pepper (C. annuum) hybrids along with 19 of their respective parents. We were also able to identify how productive certain crossing combinations were at expressing a significant amount of positive heterosis for different characteristics of interest. From our correlation analyses, we were able to identify that a significant association can exist between fruit weight and fruit diameter, as well as when other characteristics were evaluated. In all, our results were able to reveal how effective certain combinations of parent material are towards production of offspring with improved traits expressing appreciable fruit characteristics and elevated phytochemical concentrations. Finally, the quantitative measurements produced in our F2 molecular marker experiment found significant amounts of variation for both flavonoids (quercetin and luteolin) and AA expression. It was evident that incorporation of the necessary genes of interest present within fruit tissue across this F2 family for these different phytochemicals were passed from ?Ca377? (P1) to several of these offspring. Three candidate primers were eventually identified for their potential polymorphic expression. However, after statistically analyzing the results, only one primer was identified as expressing a significant association (although the value was still relatively low) of variability with respect to luteolin. We also identified a significant association between quercetin and luteolin, quercetin and total flavonoids (quercetin+luteolin), as well as, luteolin and total flavonoids (quercetin+luteolin) in fruit tissues of different pepper material. From our results, we were able to arguably conclude that an environmental component may serve a more essential role in activating the necessary physiological processes to produce specific secondary metabolites. Although our RAPD technique was fairly straightforward and useful, some may argue that a more reliable technique would have been better. Therefore, we postulate that success may be possible in the near future if a different molecular marker technique is used.Item The effect of quercetin on exercise induced cytokine response in trained cyclists(2012-12) Chou, Ting-Heng; Coyle, Edward F., 1952-; Brothers, Robert MQuercetin is a flavonoid found in commonly consumed fruits and vegetables that has exhibited powerful antioxidant and anti-inflammatory properties in rodents and in vitro. In humans, the effect of quercetin on exercise induced oxidative stress and inflammation is still equivocal and need to be further investigated. A powerful antioxidant such as quercetin may inhibit the high levels of oxidative stress and inflammation associated with the high volume and intensity of exercise training seen with endurance-trained individuals. PURPOSE: To determine the effect of 28 days of daily quercetin supplementation on intensive endurance exercise induced cytokine response. vi METHODS: Thirteen trained cyclists (VO2peak 58.8 ± 3.9 ml/kg/min) were recruited for this study from the University of Texas at Austin and the local Austin, Texas community and participated in this placebo controlled, randomized, crossover designed study. After initial assessment of baseline data (VO2peak, lactate threshold, and two familiarization time trials), participants began daily supplementation with either an antioxidant supplement containing vitamins and quercetin (Q-VIT: 1000mg quercetin, 820mg Vitamin C, 40mg Vitamin B3) or the same vitamin supplement without quercetin (VIT: 820mg Vitamin C, 40mg Vitamin B3). A simulated time trial using an electromagnetically braked cycle ergometer in which subjects had to complete a set amount of work (kJ) as fast as possible was performed on the last day of supplementation. Blood collection was performed at three time points of the time trial days: before exercise (PRE), after warm up (MIN 20), and immediately after time trial exercise (POST). Measured plasma markers were Interleukin-6 (IL-6), C-Reactive Protein (CRP), and Interleukin-10 (IL-10). RESULTS: Q-VIT compared to VIT had no effect on pre, min 20 and post exercise plasma IL-6, CRP, and IL-10 ( P= 0.7, 0.08, and 0.32 respectively). However there was a trend that Q-VIT lowered plasma CRP compare to VIT ( P = 0.08). CONCLUSION: Chronic supplementation for 28 days with a quercetin based antioxidant supplement did not affect plasma cytokine before during or after exercise. The results of the current study suggest that chronic supplementation with quercetin does not influence plasma cytokine and exercise induced cytokine response in endurance-trained athletes.Item The effects of quercetin on cycling time trial performance(2012-05) Van Pelt, Douglas; Coyle, Edward F., 1952-; Brothers, Robert M.Quercetin is a flavonoid found in commonly consumed fruits and vegetables that has exhibited powerful antioxidant and anti-inflammatory properties in rodents and in vitro. In humans, the ergogenic effects of antioxidant supplementation on exercise performance and adaptations are still equivocal and need to be further investigated. A powerful antioxidant such as quercetin may inhibit the high levels of oxidative stress associated with the high volume and intensity of exercise training seen with trained individuals. There have been equivocal findings thus far regarding the ergogenic effect of either acute or chronic supplementation of quercetin on exercise performance. PURPOSE: To determine the effect of 28 days of daily quercetin supplementation on cycling time trial performance and the associated exercise performance variables. METHODS: Thirteen trained cyclists (VO2peak 58.8 ± 3.9 ml/kg/min) were recruited for this study from the University of Texas at Austin and the local Austin, Texas community and participated in this placebo controlled, randomized, crossover designed study. After initial assessment of baseline data (VO2peak, lactate threshold, and two familiarization time trials), participants began daily supplementation of either an antioxidant supplement containing vitamins and quercetin (Q-VIT: 1000mg quercetin, 820mg Vitamin C, 40mg Vitamin B3) or the same vitamin supplement without quercetin (VIT: 820mg Vitamin C, 40mg Vitamin B3). A simulated time trial using an electromagnetically braked cycle ergometer in which subjects had to complete a set amount of work (kJ) as fast as possible was performed on the last day of supplementation. Measured performance variables included: time to completion, average power output, average oxygen consumption (VO2), Respiratory Exchange Ratio (RER), gross mechanical efficiency (GE), heart rate (HR), and rating of perceived exertion (RPE). RESULTS: Quercetin had no effect on HR, RER, power output, or RPE. There was also no difference in time to complete the time trial between treatments. However, an approximately ~2% higher, but not significantly different, VO2 during Q-VIT supplementation significantly lowered the GE compared to VIT (Q-VIT: 20.49 ± 0.26 % and 19.94 ± 0.33 %; VIT: 20.9 ± 0.24 % and 20.37 ± 0.33 %; p < .01) at 15 and 30 min respectively. CONCLUSION: Chronic supplementation for 28 days with a quercetin based antioxidant supplement lowered cycling gross efficiency in well trained cyclists, but it did not affect performance time. The results of the current study suggest that chronic supplementation with quercetin does not influence aerobic exercise performance in well trained athletes.Item Quercetin and Chlorogenic Acid Mitigate DSS-Induced Changes in Expression of Select Pro-Inflammatory Cytokines and Short Chain Fatty Acid Transporter Genes(2012-10-19) Piefer, LeighQuercetin (Q) and chlorogenic acid (CA), two bioactive compounds found in stonefruits, may protect against inflammation and cancer because of anti-cancer, anti-oxidant, and anti-inflammatory properties. Since these compounds reach the colon undigested, they affect the luminal environment before they are metabolized by the microbiota and transported into epithelial cells. We hypothesized that Q and CA may suppress expression of pro-inflammatory molecules, alter the luminal environment, and alter the cell cycle, thereby protecting against injury/colitis. To test this hypothesis, 63 male weanling rats were given one of three diets (basal, 0.45% Q, 0.05% CA). After 3 wk of acclimation, colitis was induced in 11 rats/diet [3% dextran sodium sulfate (DSS), 48 h, 3 treatments, 2 wk separation] and 10 rats/diet served as control (0% DSS). All rats were terminated at wk 9. Measurements included: fecal moisture content, fecal short chain fatty acid (SCFA) concentrations (gas chromatography), epithelial injury and inflammation in the distal colon, proliferation (PCNA), and NF-kappaB activity (ELISA method) and gene expression (real time RT-PCR) in mucosal scrapings. Fecal moisture content was significantly increased by DSS exposure (p<0.05), and never returned to control levels. Fecal SCFA concentrations also increased with DSS (acetate, p<0.05; butyrate, p<0.05). Increased SCFA concentrations could indicate decreased SCFA uptake. Experimental diets were able to mitigate DSS-induced decreases in SLC5A8 (SCFA transporter) expression. DSS significantly increased injury (p<0.0001) and inflammation (p<0.01) scores. Compared to the basal diet, CA decreased NF-kappaB activity in DSS-treated rats (p<0.05). Q and CA may maintain healthy regulation of NF-kappaB through maintaining expression levels of IkappaBalpha and Tollip, molecules that inhibit NF-kappaB activation. Q and CA mitigated DSS-induced increases in pro-inflammatory cytokine expression, specifically IL-1. Q enhanced expression of injury-repair molecule FGF-2 (p<0.01), but neither diet nor DSS treatment altered proliferation. Although Q and CA did not protect against DSS-induced increases in injury and inflammation scores or fecal SCFA concentrations, their influence on expression of injury repair molecules, pro-inflammatory cytokines, SCFA transport proteins, and NF-kappaB inhibitory molecules suggests beneficial influences on major pathways involved in DSS-induced injury/inflammation. The combined benefit of these compounds could have additive/synergistic effects and, therefore, deserve further examination.Item The electronic structures and photochemistry of flavins and indoles(Texas Tech University, 1969-08) Kurtin, William ENot available