The Protective Effects And Mechanism Of Mulberry By Simulated Digestion On Heptic Cells Damage

Mulberry is rich in nutrients and bioactive components. For scientific evaluation of the nutritional value and biological function of mulberry, bioactive components (total phenolic, total flavonoids, anthocyanins and proanthocyanidins) content and antioxidant capacity of mulberry with in vitro digestion were analysed. The protective effects and mechanism of gastrointestinal digested mulberry on acrylamide-induced damage in HepG2 cells were obeserved. The main research results were as follows:(1) Effect of simulated digestion on bioactive components content and antioxidant capacity of mulberryTotal phenolic, total flavonoid, anthocyanins and proanthocyanidins content of bioaccessible fraction (MBD) was 463.88±5.81mg GAE/300mL,363.51±6.73mg RutinE/300mL,44.74±2.29mg CyaE/300mL,217.43±7.01mg CatechinE/300mL individually, and the antioxidant capacity was determined in vitro and in vivo. Higher values of phenolic, anthocyanins and proanthocyanidins and lower values of flavonoid and antioxidant capacity were observed in MBG compared with MBD. Higher values of phenolic, anthocyanins and proanthocyanidins and antioxidant capacity in vitro were observed in initial chemical extracts (MBE), but a lower antioxidant capacity in vivo were measured in MBE compared with MBD.(2) Protctive effects of mulberry digest against acrylamide-induced damage in HepG2 cellsThe cell viability was analysed by MTT assay. The cell viability of HepG2 cells decreased by 49.32% compared with control and increased by 6.78% and 21.88% for the pretreatment with high-dose MBE and MBD individually. Dynamic fluorescence visualization technology, molecular probes and other modern molecular cytology technique were used to evaluate the protective effects of mulberry on the inhibition of AA-induced cytotoxicity. The obtained results indicated that, AA caused significant generation of ROS and depletion of GSH, impaire of mitochondria membrane and oxidative damage of nucleus due to the oxidative stress induced by AA on lipids, protein and DNA in HepG2 cells, while administration of MBE or MBD, were remarkbly attenuated the generation of ROS and depletion of GSH, impaire of mitochondria membrane and oxidative damage of nucleus caused by AA cytotoxicity.(3) Effect of mulberry and acrylamide on antioxidant enzymes and gene expression of Nrf2-ARE signal pathway in HepG2 cellsCompared to control, SOD and CAT activity were evidently decreased by 49.44% and 72.57% indiviually due to the oxidative stress induced by AA, and CAT activity incresed by 23.66% with pretreatment of lmg/mL MBD. Real-time qPCR was used to measure the gene expression of Nrf2, HO-1, y-GCS and GSTP1 in HepG2 cells. The results indicated that Nrf2, HO-1, y-GCS and GSTP1 gene expresssions were up-regulated to promot cellular antioxidant avtivity and inhibit the oxidative damage induced by AA. Moreover, the gene expression was decresed by pretreatment of MBE or MBD and the results suggested that MBE and MBD alleviated the oxidative stress induced by AA.In summary, the bioactive components and antioxidant capacity were significantly influenced by the process of simulated digestion. And the protective effects of mulberry digest against AA-induced oxidative damage in HepG2 cells was evaluated and the mechamism is closely to mulberry’s antioxidant activity. This study provided a train of thought and method for scientifically evaluating the antioxidant activity and the protective effects against heptic cells oxidative damage of fruit and vegetable and a certin basis for development of natural, safe and effective mulberry functional products.