Tao Bao

Protective effect of wild raspberry (Rubus hirsutus Thunb.) extract against acrylamide-induced oxidative damage is potentiated after simulated gastrointestinal digestion.

Raspberry is well known as rich source of antioxidants, such as polyphenols and flavonoids. However, after consumption, the antioxidants are subjected to digestive conditions within the gastrointestinal tract that may result in structural and functional alterations. Our previous study indicated that acrylamide (AA)-induced cytotoxicity was associated with oxidative stress. However, the protective effect of wild raspberry extract produced before and after in vitro gastrointestinal digestion against AA-induced oxidative damage is unclear. In the present study, we found that wild raspberry extract produced after digestion (RD) had a pronounced protective effect against AA-induced cytotoxicity compared with that produced before digestion (RE). Further investigation indicated that RD significantly inhibited AA-induced intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) collapse and glutathione (GSH) depletion. Moreover, LC-MS analysis revealed that wild raspberry underwent gastrointestinal digestion significantly increased the contents of esculin, kaempferol hexoside and pelargonidin hexoside.

Protective property of mulberry digest against oxidative stress – A potential approach to ameliorate dietary acrylamide-induced cytotoxicity

The aim of this study was investigating the protective effect of mulberry digest (MBD) on acrylamide-induced oxidative stress. Composition analysis of MBD revealed that it contained six major phenolic compounds (quercetin-3-O-rutinoside, quercetin hexoside, quercetin rhamnosylhexoside hexoside, kaempferol rhamnosylhexoside, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside). After in vitro digestion, the contents of two anthocyanins were both decreased significantly, while the contents of four flavonoid glycosides were all increased. In addition, MBD was found to successfully suppress acrylamide-induced ROS overproduction, restore the mitochondrial membrane potential, and inhibit the mitochondrial membrane lipid peroxidation and glutathione depletion. More interestingly, the protective effect of MBD against acrylamide-induced oxidative damage was enhanced compared with mulberry fruits without digestion (MBE). Further study revealed that MBD enhanced the cell resistance capacity to acrylamide-induced oxidative stress, rather than its direct reaction with acrylamide. Overall, our results indicate that MBD provides a potent protection against acrylamide-induced oxidative stress.

A recyclable protein resource derived from cauliflower by-products: Potential biological activities of protein hydrolysates

Cauliflower by-products (CBP) are rich in leaf protein. Every year tons of CBP will lead to environmental pollution. Therefore, this study was conducted to extract leaf protein from CBP and investigate its biological activities. Our results showed that the optimal extraction parameters were: a liquid to solid ratio of 4mL/g, a pH of 11, an ultrasonic extraction lasting 15min, and at an applied power of 175W. Under these optimized conditions, 12.066g of soluble leaf protein (SLP) was obtained from 1000g of CBP and its extraction yield was 53.07%. The obtained SLP was further hydrolysed by Alcalase and the SLP hydrolysate (SLPH) showed a potent angiotensin I-converting enzyme (ACE) inhibitory activity with an IC50 value of 138.545μg/mL in vitro. In addition, SLPH promoted the glucose consumption and enhanced the glycogen content in HepG2 cells. Overall, our results suggested that CBP may be recycled for designing future functional foods.

Comparison of the protective effect of black and white mulberry against ethyl carbamate-induced cytotoxicity and oxidative damage

Increasing evidence indicates that crude extracts derived from mulberry confer protection against oxidative stress. However, the antioxidant capacity of mulberry extract among different cultivars remains elusive. The main objective of the present study was therefore to investigate the effect of black mulberry extract (BMB) and white mulberry extract (WMB) on ethyl carbamate (EC)-induced cytotoxicity and oxidative stress. This study showed that the contents of total phenolics, total flavonoids, total procyanidins, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and pelargonidin-3-O-glucoside of BMB were higher than that of WMB. Moreover, our results showed that phenolics-abundant BMB was stronger than WMB in scavenging ABTS and DPPH free radicals. BMB was more effective in ameliorating EC-induced cytotoxicity by inhibiting excessive ROS generation, suppressing mitochondrial dysfunction and increasing GSH concentration in HepG2 cells than WMB. Taken together, our study revealed that BMB afforded better protection against EC-caused cytotoxicity than WMB.

Mulberry Fruit Extract Affords Protection against Ethyl Carbamate-Induced Cytotoxicity and Oxidative Stress

Ethyl carbamate (EC) is a food and environmental toxicant and is a cause of concern for human exposure. Several studies indicated that EC-induced toxicity was associated with oxidative stress. Mulberry fruits are reported to have a wide range of bioactive compounds and pharmacological activities. The present study was therefore aimed to investigate the protective property of mulberry fruit extract (MFE) on EC-induced cytotoxicity and oxidative stress. Chemical composition analysis showed that total phenolic content and total flavonoid content in MFE were 502.43 ± 5.10 and 219.12 ± 4.45 mg QE/100 g FW. Cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were the major anthocyanins in MFE. In vitro antioxidant studies (DPPH, ABTS, and FRAP assays) jointly exhibited the potent antioxidant capacity of MFE. Further study indicated that MFE protected human liver HepG2 cells from EC-induced cytotoxicity by scavenging overproduced cellular ROS. EC treatment promoted intracellular glutathione (GSH) depletion and caused mitochondrial membrane potential (MMP) collapse, as well as mitochondrial membrane lipid peroxidation, whereas MFE pretreatment significantly inhibited GSH depletion and restored the mitochondrial membrane function. Overall, our study suggested that polyphenolic-rich MFE could afford a potent protection against EC-induced cytotoxicity and oxidative stress.

Systematic evaluation of bioactive components and antioxidant capacity of some new and common bayberry cultivars using an in vitro gastrointestinal digestion method

This study was aimed to investigate the impact of in vitro gastrointestinal digestion on some common and new bayberry cultivars. The contents of total phenolics (246-669mg gallic acid equivalents/kg FW (fresh weight)), flavonoids (116-689mg quercetin-3-O-rutinoside equivalents/kg FW), procyanidins (28-133mg catechin equivalents/kg FW) and anthocyanins (1-7mg cyaniding-3-O-glucoside equivalents/kg FW) were detected in digested cultivars. HPLC-TOF-MS analysis identified 17 phenolic compounds in digested sample. Among all digested cultivars, the new cultivars Anhaizaomei (ABTS, IC50=2.95mg/mL; FRAP, 401.32mg vitamin C equivalents (VCE)/kg FW) and Yingsi (ABTS, IC50=3.28mg/mL; FRAP, 400.81mg VCE/kg FW) showed better in vitro antioxidant capacity. Further cellular assay indicated that the common cultivar Dongkui (2mg/mL) possessed the strongest ROS scavenging activity. The comprehensive evaluation of bioactive components and antioxidant properties using principal component analysis suggests that common cultivar Dongkui, new cultivars Yingsi and Anhaizaomei could be considered as dietary supplements.

Antioxidant and antidiabetic activity of blackberry after gastrointestinal digestion and human gut microbiota fermentation

Blackberry fruit contains high levels of polyphenols particularly anthocyanins which contribute to its biological activities. Bioavailability of polyphenols especially anthocyanins is generally low, it has been proposed that metabolites from polyphenol biotransformation under colonic fermentation are components that exert health benefits. In this study, blackberry was subjected to simulated gastrointestinal digestion and gut microbiota fermentation at different time intervals (0-48 h) to study the changes in bioactive components, its antioxidant and antidiabetic activities. Phenolic compounds, during digestion and fermentation were also analysed. Gut metabolites of blackberry significantly increased the glucose consumption and glycogen content in HepG2 cells. Furthermore, gut metabolites ameliorated high glucose plus palmitic acid-induced ROS overproduction, mitochondrial membrane collapse, and glutathione depletion in HepG2 cells. The mechanism of antidiabetic activity of blackberry was via its potent antioxidant activity. Therefore, our results suggest that blackberry could be recommended as a functional food due to potential antioxidant and antidiabetic activity.