Doenjang, A Korean Traditional Fermented Soybean Paste, Ameliorates Neuroinflammation and Neurodegeneration in Mice Fed a High-Fat Diet

Abstract

Obesity is considered a risk factor for neurodegeneration. Because fermentation of soybean increases contents of various bioactive compounds with anti-obesity and anti-diabetic activities, we investigated the protective effect of doenjang, a Korean traditional fermented soybean paste, against neuroinflammation and neurodegeneration in the cortex and hippocampus of mice fed a high-fat (HF) diet. C57BL/6J mice were fed a low-fat diet, an HF diet, an HF-containing steamed soybean diet, or an HF-containing doenjang (DJ) diet for 11 weeks. Doenjang consumption alleviated hippocampal neuronal loss, which was increased by the HF diet. Accordingly, we observed higher cell proliferation and neurotrophic factor mRNA levels in the DJ group. Contents of oxidative metabolites and mRNA levels of oxidative stress- and neuroinflammation-related genes were lower in the DJ group compared to the HF group. Dietary doenjang reduced β-amyloid peptide (Aβ) levels by regulating gene expressions involved in Aβ production and degradation. Furthermore, doenjang consumption reduced tau hyperphosphorylation induced by HF feeding. Overall, doenjang was more effective than steamed soybean in suppressing neuroinflammation and neurodegeneration in mice fed an HF diet. These results suggest that bioactive compounds produced during the fermentation and aging of soybean may be involved in the enhanced neuroprotective effects of doenjang.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

“…On the other side, doenjang, a Korean traditional fermented soybean pastry alleviated hippocampal neuronal loss and enhanced cell proliferation in HFD-fed mice as well as reduced oxidative stress markers (less oxidative metabolites and lower levels of oxidative stress- and neuroinflammation-related genes). Dietary doenjang reduced Aβ and tau phosphorylation [ 333 ]. Furthermore, genistein has shown the capacity to improve metabolism and induce browning via hypothalamus gene expression regulation.…”

Fermented Soy Products: Beneficial Potential in Neurodegenerative Diseases

“…The nutritional values and medicinal effects of soybean or its constituents are well documented [ 6 , 7 , 8 , 9 , 10 , 11 ]. In several Asian countries, including China, Indonesia, Japan, and Korea, fermented soybean products, such as doenjang (soybean paste and Japanese miso ), ganjang (soy sauce), natto , and tempeh , have been extensively consumed since ancient times.…”

Anti-Obesity Effect of an Ethanol Extract of Cheongchunchal In Vitro and In Vivo

“…Many studies focused on anti-obesity drugs and functional foods are being conducted to address the recently increasing number of obesity cases [ 22 , 23 ]. Additionally, many studies are being conducted to verify the effectiveness of anti-obesity drugs and functional foods with natural substances, as well as to reduce the various side effects of some commercial anti-obesity drugs [ 24 , 25 , 26 ]. This study was a basic study aimed at developing anti-obesity drugs and functional foods from natural substances.…”