Investigation Into the Chemical Constituents and Cytotoxic Effects on Lung Cancer Cells of the Rhizomes of <scp><i>Polygonum bistorta</i></scp> L. and <i>Polygonum paleaceum</i> Wall.

The medicinal herb market frequently blends the rhizome of Polygonum bistorta L. (RPB) with the rhizome of Polygonum paleaceum Wall. (RPP) for sale. Therefore, it is crucial to investigate the chemical compositions and the cytotoxic effects on lung cancer of RPB and RPP. In this study, we utilized ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS), employing diagnostic fragment ions and neutral loss techniques, to identify the chemical compositions in RPB and RPP. Furthermore, the cytotoxicity of RPB and RPP on H1299 and A549 cells was evaluated using the cell counting kit-8 (CCK-8) assay. A total of 90 compounds were tentatively characterized in RPB and RPP, including 25 gallic acid derivatives, 46 catechin derivatives, and 19 other compounds, with seven compounds verified using authentic standards. The chemical compositions of RPB and RPP were found to be largely similar, with significant differences observed only in the content of individual components. RPB and RPP exhibit significant cytotoxicity against H1299 cells, with IC₅₀ values of 163.8 and 187.7 μg/mL, respectively. However, their cytotoxicity was relatively lower against A549 cells. The results indicate that there is no significant difference in the chemical composition or lung cancer cytotoxicity between RPB and RPP.