Flavonoids and Organic Acids Affect Phase II Metabolism based on the Regulation of UGT1A1 Expression and Function

Lin Zhang; Xuerong Zhang; Caiyan Wang

doi:10.2174/0115734099300793240509103320

Flavonoids and Organic Acids Affect Phase II Metabolism based on the Regulation of UGT1A1 Expression and Function

Curr Comput Aided Drug Des. 2024 May 17. doi: 10.2174/0115734099300793240509103320. Online ahead of print.

Authors

Lin Zhang^{1

2}, Xuerong Zhang¹, Caiyan Wang¹

Affiliations

¹ State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangzhou University of Chinese Medicine, International Institute for Translational Chinese, Guangzhou, 510006, China.
² School of Pharmacy, Jiangxi Science and Technology Normal University, Jiangxi, 330013, China.

PMID: 38766819
DOI: 10.2174/0115734099300793240509103320

Abstract

Background: Exogenous substances modulate metabolism by regulating the expression and function of UDP-glycosyltransferases (UGTs). However, the exact mechanism in the intestine was rarely understood. Herein, we explored the effects of representative flavonoids and organic acids on the regulation of UGT1A1.

Methods: MTT assays and western blot analysis were used to explore the effect of polyphenols. X-ray diffraction was used to reveal the catalytic mechanisms of UGTs.

Results: MTT assays showed that these compounds basically had no cytotoxicity, even in concentrations up to 200 μM. Then, through western blot assays, UGT1A1 expression was increased after being treated with liquiritigenin and caffeic acid. Furthermore, liquiritigenin and caffeic acid enhanced the nuclear translocation of Nrf2. Moreover, a 2.5-Å crystal structure of the complex containing UGTs C-terminal domain and organic acid was solved, and the UDPGA binding pocket could be occupied by organic acid, suggesting the enzyme activity might be impaired by organic acid.

Conclusion: Above all, liquiritigenin and caffeic acid maintained the metabolism balance by upregulating the expression of UGT1A1 via Nrf2 activation and inhibiting the enzyme activity in Caco-2 cells.

Keywords: Crystal structure; Nrf2; UGTs.; mechanism; polyphenols.