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

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

Advances in Green Chemistry © 2022