Bioactivity-guided isolation of natural anti-inflammatory polyphenols from the tender shoots of Tamarix chinensis Lour.: A medicinal and landscape plant

Tamarix chinensis Lour. ( T. chinensis ) is a prevalent halophyte species indigenous to the coastal, arid, and semiarid regions of China. It fulfills various roles, including soil amelioration, ornamental applications, and utilization as fuel, fertilizer, and medicinal materials. Traditionally employed in Chinese medicine for the alleviation of wind and dampness, T. chinensis is recognized for its anti-inflammatory properties; however, its principal active compounds have yet to be identified. This study represents the first application of an activity-guided approach to elucidate the key anti-inflammatory constituents of T. chinensis , integrating chemical isolation with a lipopolysaccharide (LPS)-induced Tg(mpx:EGFP) transgenic zebrafish model. The results showed that the 50% ethanol extract of T. chinensis and its two subfractions, which were isolated via HP 2 MGL resin column chromatography, significantly attenuated neutrophil recruitment in the yolk sac of zebrafish. The efficacy of these fractions was ranked as follows: Sub-fraction B2 > B3 > 50% ethanol extract. Within Subfraction B2, three primary constituents were identified—quercetin-3-glucuronide, ellagic acid, and kaempferol-3-glucuronide—with kaempferol-3-glucuronide accounting for 15.59% of this subfraction. All of these compounds markedly ameliorated LPS-induced inflammation in zebrafish. Notably, kaempferol-3-glucuronide increased nrf2 mRNA expression, decreased reactive oxygen species levels, upregulated the expression of antioxidant enzyme-encoding genes, and inhibited nf-κb gene expression, thereby suppressing the expression of inflammatory mediators such as tnf-α , il-1β , cox2 , and inos . This research highlights the potential high-value utilization of T. chinensis . • Three principal components were purified from the industrial crop T. chinensis. • They could reduce ROS-mediated oxidative stress and inflammation in zebrafish. • The results support the valuable use of T. chinensis and its products.