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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

HPLC chromatograms of raspberry extracts produced before and after simulated gastrointestinal digestion. (a) Chromatogram of RE. (b) Chromatogram of RD. (c) Chemical structures of identified compounds.
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fig7: HPLC chromatograms of raspberry extracts produced before and after simulated gastrointestinal digestion. (a) Chromatogram of RE. (b) Chromatogram of RD. (c) Chemical structures of identified compounds.

Mentions: The aforementioned results revealed that EC could result in oxidative stress damage in Caco-2 cells, whereas RD were more effective than RE in attenuating EC-induced oxidative damage. The possible explanation for this phenomenon may be due to structural modification or release of biological active components which were entrapped in food matrix after in vitro simulated gastrointestinal digestion [12, 23]. Therefore, HPLC-ESI-MS was employed to analyze the composition of raspberry extracts produced before and after in vitro simulated gastrointestinal digestion. HPLC chromatograms displayed the major changes between RE and RD extracts in terms of the content of identified compounds. As we can see from Figures 7(a) and 7(b), the contents of three identified compounds were increased significantly after in vitro digestion. According to their MS and MS2 data, these compounds were identified as esculin (compound 1) [29], kaempferol O-hexoside (compound 2) [30], and pelargonidin O-hexoside (compound 3) [31], respectively. Berries are rich in phytochemicals, such as anthocyanins, flavonoids, and various phenolic acids, which can provide potent protection against oxidative damage [32, 33]. Kaempferol O-hexoside and pelargonidin O-hexoside are common phytochemicals in berries; they can effectively remove intracellular ROS and increase the total antioxidant activity [8, 34]. Besides, esculin was a novel compound identified in the wild raspberry extract and has been reported to be effective in protecting cells against DNA damage triggered by oxidative stress and scavenging ROS levels [35]. Flavonoids and anthocyanins are mainly located in the vacuoles of cells. Under the simulated gastrointestinal digestion condition, the extreme pH and the enzymatic digestion may fully break down raspberry matrix and vacuoles [36], which leads to the release of these compounds completely. Moreover, some reports considered that the formation of glycoside was increased after digestion probably due to the partial digestion of the dietary fiber present in the matrix [37], which may be beneficial for the formation of anthocyanins including compound 3 (pelargonidin O-hexoside). Overall, we concluded that the better performance of RD in suppressing EC-induced oxidative damage might be partially attributed to these three compounds.


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)

HPLC chromatograms of raspberry extracts produced before and after simulated gastrointestinal digestion. (a) Chromatogram of RE. (b) Chromatogram of RD. (c) Chemical structures of identified compounds.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4696417&req=5

fig7: HPLC chromatograms of raspberry extracts produced before and after simulated gastrointestinal digestion. (a) Chromatogram of RE. (b) Chromatogram of RD. (c) Chemical structures of identified compounds.
Mentions: The aforementioned results revealed that EC could result in oxidative stress damage in Caco-2 cells, whereas RD were more effective than RE in attenuating EC-induced oxidative damage. The possible explanation for this phenomenon may be due to structural modification or release of biological active components which were entrapped in food matrix after in vitro simulated gastrointestinal digestion [12, 23]. Therefore, HPLC-ESI-MS was employed to analyze the composition of raspberry extracts produced before and after in vitro simulated gastrointestinal digestion. HPLC chromatograms displayed the major changes between RE and RD extracts in terms of the content of identified compounds. As we can see from Figures 7(a) and 7(b), the contents of three identified compounds were increased significantly after in vitro digestion. According to their MS and MS2 data, these compounds were identified as esculin (compound 1) [29], kaempferol O-hexoside (compound 2) [30], and pelargonidin O-hexoside (compound 3) [31], respectively. Berries are rich in phytochemicals, such as anthocyanins, flavonoids, and various phenolic acids, which can provide potent protection against oxidative damage [32, 33]. Kaempferol O-hexoside and pelargonidin O-hexoside are common phytochemicals in berries; they can effectively remove intracellular ROS and increase the total antioxidant activity [8, 34]. Besides, esculin was a novel compound identified in the wild raspberry extract and has been reported to be effective in protecting cells against DNA damage triggered by oxidative stress and scavenging ROS levels [35]. Flavonoids and anthocyanins are mainly located in the vacuoles of cells. Under the simulated gastrointestinal digestion condition, the extreme pH and the enzymatic digestion may fully break down raspberry matrix and vacuoles [36], which leads to the release of these compounds completely. Moreover, some reports considered that the formation of glycoside was increased after digestion probably due to the partial digestion of the dietary fiber present in the matrix [37], which may be beneficial for the formation of anthocyanins including compound 3 (pelargonidin O-hexoside). Overall, we concluded that the better performance of RD in suppressing EC-induced oxidative damage might be partially attributed to these three compounds.

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