Category Archives: b_original_articles

Fermented Pueraria lobata alleviates H2O2-induced oxidative stress in zebrafish by regulating the Nrf2/ARE signaling pathway

Abstract
This study aimed to investigate the changes in the composition of Pueraria lobata after fermentation by Pichia kudriavzevii and its impact on the antioxidant capacity of zebrafish. The LC-MS was utilized to analyze the constituents of the aqueous extract of P. lobata (non-fermented, AEP) and the fermented broth of P. lobata (fermented, FBP). An H2O2-induced oxidative stress model (OS) in
zebrafish was constructed, and antioxidant enzyme activities and expression levels of antioxidant-related genes were compared after zebrafish were exposed to AEP and FBP. It was found that the composite species of FBP was reduced by 6.45% compared with AEP after fermentation by
P. kudriavzevii. The main component of P. lobata is isoflavones, which increase by 1.27% after
fermentation. Moreover, the FBP significantly reduced the increase in MDA caused by H2O2
 in zebrafish and significantly increased T-AOC activity in vivo. In addition, the relative expression of genes connected to the antioxidant Nrf2/ARE signaling pathway was markedly reduced in the FBP group, approaching the level of normal control samples. Interestingly, among these effects, the FBP group was more significant than the AEP group. FBP promotes the expression of antioxidant factors and alleviates the oxidative stress response of Zebrafish. These findings provide a reference for the development and application of the antioxidant properties of fermented P. lobata in the food industry.


Keywords: Pueraria lobata, Antioxidant, Pichia kudriavzevii, Nrf2/ARE, Zebrafish

Enhanced fermentation by Rhizopus oligosporus promotes antioxidant capacity and intestinal development of Tibetan tea in mice

Abstract
Fermentation of Tibetan tea is necessary during processing and its quality will be under the influence of microorganisms. In this study, Rhizopus oligoporus was inoculated in Tibetan tea for intensive fermentation to investigate its effect on the antioxidant function of Tibetan tea in vitro and in vivo and on the intestinal development of mice. After intensive fermentation of Tibetan tea by R. oligoporus,
it was prepared as tea extract and the change of its antioxidant capacity was measured. Meanwhile, mice were administered the tea extracts. Antioxidant activity in liver and the effects on intestinal development of mice were determined. The results showed that the total antioxidant capacity (T-AOC), the ability to scavenge hydroxyl radicals and ABTS radical scavenging capacity of fermented tea were remarkably higher compared with non-fermented tea (P < 0.05). Fermented tea also increased T-AOC, catalase (CAT) and glutathione (GSH) activities and decreased malondialdehyde (MDA) content in the livers of mice (P < 0.05). The mRNA expression of SOD, CuZn-SOD, GSH and IκBα in the liver and intestinal barrier genes Mucin-1, Mucin-2, Claudin-1 and ZO-1 were upregulated (P < 0.05), whereas the mRNA expression of NF-κB and COX-2 were downregulated in the
liver. In addition, fermented tea increased the numbers of
Lactobacillus spp. and Bifidobacterium spp. in t
etan tea was strengthened, and it also enhanced the intestinal development of mice.he intestine of mice. The colonic muscle layer of mice thickened, and the crypt became shallower. After the intensified fermentation of R. oligoporus, the antioxidant capacity of Tibetan tea was strengthened, and it also enhanced the intestinal development of mice.

Keywords: Tibetan tea; Rhizopus oligoporus; antioxidant; fermentation; probiotics; intestinal barrier