Identification of Bioactive Compounds from Citri Reticulatae Pericarpium and Evaluation of Their Uric Acid-Lowering Activity.

Citri Reticulatae Pericarpium, the dried and mature peel of wild Citrus reticulata Blanco and its cultivated varieties in the rutaceae family, is an important herb and condiment in Chinese medicine. At present, there are few relevant reports, especially in-depth reports, on the discovery of effective anti-gout natural products from CRP. In this study, four compounds were extracted and characterized from CRP using 70% ethanol, RP-C18, thin layer chromatography (TLC), Sephadex LH-20, high performance liquid chromatography (HPLC), and nuclear magnetic resonance spectroscopy (NMR). Additionally, monomer compounds (apigenin, luteolin) in CRP, along with those isolated from CRP, were investigated through molecular docking and in vitro assessment of their XOD inhibitory activity. Notably, the lowest binding energy (-10.3 kcal/mol) and IC₅₀ value (76.24 µg/mL) denoted a strong inhibitory effect of isosakuranetin with XOD. Further studies showed that isosakuranetin could significantly reduce XOD activity and uric acid levels in xanthine-induced BRL-3A cells. This research elucidates, for the first time, the uric acid-lowering effects of isosakuranetin, offering valuable insights into the potential mechanisms underlying its properties. This study provides a basis for the development of uric acid-lowering products from CRP and in-depth mechanism research of uric acid-lowering compounds.