Optimization of <i>Jiuzao</i> protein hydrolysis conditions and antioxidant activity <i>in vivo</i> of <i>Jiuzao</i> tetrapeptide Asp-Arg-Glu-Leu by elevating the Nrf2/Keap1-p38/PI3K-MafK signaling pathway.
Jiang. Yunsong Y; Wang. Rui R; Yin. Zhongtian Z; Sun. Jinyuan J; Wang. Bowen B; Zhao. Dongrui D; Zeng. Xin-An XA; Li. Hehe H; Huang. Mingquan M; Sun. Baoguo B
Key Findings
- Pepsin gave the highest yield of DREL from Jiuzao protein (≈158 mg per kg)
- DREL activated the Nrf2/Keap1‑p38/PI3K‑MafK signaling pathway and increased antioxidant enzymes in rats
- DREL reduced inflammatory cytokine release, showing anti‑inflammatory activity
- Adding DREL to baijiu did not noticeably affect taste
Practical Outcomes
- For biohackers, DREL looks like a promising antioxidant peptide that could be extracted from Jiuzao waste and possibly added to foods or drinks without altering flavor. At this stage, there’s no human dosage or safety information, so any use would be experimental and likely requires further research or sourcing from specialized suppliers.
Summary
Researchers found that a tiny protein piece called DREL, taken from a by‑product of Chinese liquor making, can boost antioxidant defenses and lower inflammation in rats by turning on the Nrf2 pathway. They also showed it can be added to the liquor without changing its flavor, suggesting it could be mixed into foods or drinks. However, the work is still in animals, with no human dosing or safety data yet.
Abstract
Tetrapeptide Asp-Arg-Glu-Leu (DREL) was isolated from Jiuzao protein hydrolysates (JPHs) by alkaline proteinase (AP) and exhibited antioxidant activity in the HepG2 cell model in the previous study. In this study, the hydrolysis method of Jiuzao protein (JP) was further optimized by using different proteinases under different conditions (i.e., temperature, time, ratio between proteinase and substrate, and pH). Considering the limitation of in vitro assays, the AAPH-induced oxidative stress Sprague-Dawley (SD) rat model was selected to measure the antioxidant capacity of DREL in vivo. Pepsin exhibited the highest hydrolysis degree under the optimum conditions after single factor analysis (SFA) among seven proteinases. The total yield of DREL in Jiuzao was 158.24 mg kg-1Jiuzao under the pepsin's optimum hydrolysis conditions determined by response surface methodology analysis (RSMA). In addition, DREL could activate the Nrf2/Keap1-p38/PI3K-MafK signaling pathway and downstream antioxidant enzymes to improve the antioxidant ability in vivo. DREL also preliminarily exhibited anti-inflammatory activity by inhibiting the secretion of inflammatory cytokines and the mediator through the activation of Nrf2. Of note, the addition of DREL in baijiu brought an inconspicuous change in the taste after sensory evaluation. This study finds out the better proteinase used for JP hydrolysis and verifies the antioxidant capacity of DREL in vivo, which provides a potential approach to apply functional components from Jiuzao for by-product utilization. Meanwhile the antioxidant function of baijiu or other foods can be increased through adding these functional peptides without affecting the original flavor and taste in the future.
Study Information
pubmed
2021
2021-06-08T00:00:00.000Z
10.1039/d0fo02852e
43
48