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Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells.

Chen W, Xu Y, Zhang L, Li Y, Zheng X - Oxid Med Cell Longev (2015)

Bottom Line: Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity.In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD.Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou 310058, China.

ABSTRACT
Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells.

No MeSH data available.


Related in: MedlinePlus

Effect of RD on EC-induced superoxide anion radicals generation in Caco-2 cells. (a) After treatment with 62.5 mM EC in the presence or absence of RE (2 mg/mL) or RD (2 mg/mL) for 24 h, cells were collected and incubated with 10 μM of DHE at 37°C for 30 min; then cells were washed with PBS and evaluated by fluorescence microscope. (b) The quantitative data of panel (a) and results were expressed as mean DHE fluorescence intensity (mean ± standard deviations). ∗p < 0.05 represents significant difference compared with EC group.
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fig3: Effect of RD on EC-induced superoxide anion radicals generation in Caco-2 cells. (a) After treatment with 62.5 mM EC in the presence or absence of RE (2 mg/mL) or RD (2 mg/mL) for 24 h, cells were collected and incubated with 10 μM of DHE at 37°C for 30 min; then cells were washed with PBS and evaluated by fluorescence microscope. (b) The quantitative data of panel (a) and results were expressed as mean DHE fluorescence intensity (mean ± standard deviations). ∗p < 0.05 represents significant difference compared with EC group.

Mentions: It was reported that EC-induced toxicity was related to the generation of ROS in lung epithelial cells [7]. On the basis of our result that EC could cause cytotoxicity in Caco-2 cell, we next studied whether EC could induce ROS overproduction in Caco-2 cells by incubation with DCFH-DA. The result displayed in Figures 2(a) and 2(b) showed that the DCF fluorescence intensity of EC group was increased to 392.76% compared with control group (its fluorescence intensity was considered as 100%), which indicated that large amount of ROS was accumulated in Caco-2 cells after EC treatment. Subsequently, we explored whether the overproduction of ROS could be scavenged by raspberry digesta (RD). As expected, comparing with that of EC group (392.76%), a sharp decrease of fluorescence intensity was observed in RE group and RD group, with the mean fluorescence intensity declining to 289.83% and 142.40%, respectively. In addition, further study (DHE staining experiment) was employed to examine whether EC could induce the generation of intracellular superoxide anion radicals (O2·−). Similar results were found and presented in Figures 3(a) and 3(b), in which Caco-2 cells pretreated with RE and RD significantly decreased the DHE fluorescence intensity to 215.88% and 120.41%, respectively, compared with solely EC-treated group (its fluorescence intensity reached 264.68%). The reason contributing to these phenomena may be the release of some bioactive phenolic components after in vitro digestion [23], since the structure of phenolic compounds that hydroxyl groups linked to phenolic rings were considered to donate electrons and neutralize reactive oxygen species [24]. As we detected that the total phenolic content was increased from 188.43 mg GAE/100 g to 254.60 mg GAE/100 g and the total flavonoid content increased from 78.30 mg RE/100 g to 103.32 mg RE/100 g after in vitro digestion. In conclusion, RD may be more effective than RE in terms of scavenging intracellular ROS and superoxide anion radicals in Caco-2 cells.


Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells.

Chen W, Xu Y, Zhang L, Li Y, Zheng X - Oxid Med Cell Longev (2015)

Effect of RD on EC-induced superoxide anion radicals generation in Caco-2 cells. (a) After treatment with 62.5 mM EC in the presence or absence of RE (2 mg/mL) or RD (2 mg/mL) for 24 h, cells were collected and incubated with 10 μM of DHE at 37°C for 30 min; then cells were washed with PBS and evaluated by fluorescence microscope. (b) The quantitative data of panel (a) and results were expressed as mean DHE fluorescence intensity (mean ± standard deviations). ∗p < 0.05 represents significant difference compared with EC group.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4696417&req=5

fig3: Effect of RD on EC-induced superoxide anion radicals generation in Caco-2 cells. (a) After treatment with 62.5 mM EC in the presence or absence of RE (2 mg/mL) or RD (2 mg/mL) for 24 h, cells were collected and incubated with 10 μM of DHE at 37°C for 30 min; then cells were washed with PBS and evaluated by fluorescence microscope. (b) The quantitative data of panel (a) and results were expressed as mean DHE fluorescence intensity (mean ± standard deviations). ∗p < 0.05 represents significant difference compared with EC group.
Mentions: It was reported that EC-induced toxicity was related to the generation of ROS in lung epithelial cells [7]. On the basis of our result that EC could cause cytotoxicity in Caco-2 cell, we next studied whether EC could induce ROS overproduction in Caco-2 cells by incubation with DCFH-DA. The result displayed in Figures 2(a) and 2(b) showed that the DCF fluorescence intensity of EC group was increased to 392.76% compared with control group (its fluorescence intensity was considered as 100%), which indicated that large amount of ROS was accumulated in Caco-2 cells after EC treatment. Subsequently, we explored whether the overproduction of ROS could be scavenged by raspberry digesta (RD). As expected, comparing with that of EC group (392.76%), a sharp decrease of fluorescence intensity was observed in RE group and RD group, with the mean fluorescence intensity declining to 289.83% and 142.40%, respectively. In addition, further study (DHE staining experiment) was employed to examine whether EC could induce the generation of intracellular superoxide anion radicals (O2·−). Similar results were found and presented in Figures 3(a) and 3(b), in which Caco-2 cells pretreated with RE and RD significantly decreased the DHE fluorescence intensity to 215.88% and 120.41%, respectively, compared with solely EC-treated group (its fluorescence intensity reached 264.68%). The reason contributing to these phenomena may be the release of some bioactive phenolic components after in vitro digestion [23], since the structure of phenolic compounds that hydroxyl groups linked to phenolic rings were considered to donate electrons and neutralize reactive oxygen species [24]. As we detected that the total phenolic content was increased from 188.43 mg GAE/100 g to 254.60 mg GAE/100 g and the total flavonoid content increased from 78.30 mg RE/100 g to 103.32 mg RE/100 g after in vitro digestion. In conclusion, RD may be more effective than RE in terms of scavenging intracellular ROS and superoxide anion radicals in Caco-2 cells.

Bottom Line: Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity.In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD.Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou 310058, China.

ABSTRACT
Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells.

No MeSH data available.


Related in: MedlinePlus