Screening for anti-proliferative and anti-inflammatory components from Rhamnus davurica Pall. using bio-affinity ultrafiltration with multiple drug targets.

Rhamnus davurica Pall. (R. davurica) has been used as a traditional medicine for many years in China and abroad and shown a wide spectrum of biological activities. Previously, we reported the phytochemical fingerprinting profile of R. davurica, its distinct anti-proliferative activities against HT-29 and SGC-7901 cell lines, and the topoisomerase I (Top I) ligands based on bio-affinity ultrafiltration and HPLC-MS (UF-HPLC-MS). Nevertheless, among the 32 peaks detected in the fingerprinting profile, the common bioactive constituents responsible for the anti-inflammatory and anti-proliferative activities in the extracts remain elusive. To further explore the specific responsible components for their diversified activities and their potential action targets/mechanisms, the method based on bio-affinity UF-HPLC-MS using therapeutic targets like Top I and cyclooxygenase 2 (COX-2) was established to rapidly screen and identify the ligands binding to these known target enzymes. As a result, 12 components were revealed as potential Top I ligands along with 11 components as potential COX-2 ligands, where several components were revealed to possess both activities. Further validations of these bioactive components have also been conducted and confirmed their highlighted activities. This integrated method of UF-HPLC-MS exhibits high efficiency in rapidly screening for multi-target bioactive components responsible for multiple pharmacological effects from the complex natural products and could be very useful to explain the complex action mechanisms of herb medicines in a complex multi-component and multi-target mode at the molecular level. Graphical abstract Schematic diagram of UF-HPLC-MS assay to screen for Top I and COX-2 ligands. The principle of the assay usually involves the following steps: incubation, ultrafiltration, and identification.