OBJECTIVE To explore the optimal purification process condition of macroporous resin on the total polyphenolic compounds of Hedyotis diffusa, and to investigate its in vitro anti-inflammatory effect.

METHODS The total polyphenols in Hedyotis diffusa were extracted by ultrasound-assisted extraction, and the adsorption effect of different macroporous resins was investigated in static adsorption-desorption equilibrium kinetic experiments to screen the optimal purification process conditions, and the anti-inflammatory activity was evaluated by the inhibition of 5-lipoxygenase(5-LOX) and cyclooxygenase-2(COX-2) assays.

RESULTS The purification of total polyphenols from Hedyotis diffusa using HPD-826 macroporous resin was found to be most effective under the following conditions: sample concentration of 1.5 mg·mL⁻¹, pH of 5.0, sample volume of 90 mL, sample flow rate of 1.0 mL·min⁻¹, elution solution ethanol volume fraction of 70%, elution solution volume of 80 mL, and elution flow rate of 1.0 mL·min⁻¹. Under these conditions, the purity of total polyphenols from Hedyotis diffusa increased from (27.13±1.36)% to (63.08±0.83)%, representing a 1.32-fold improvement. The ethanolic extract of Hedyotis diffusa with a total polyphenol concentration of 20 mg·mL⁻¹ exhibited a (57.15±7.16)% inhibition rate against 5-LOX activity, while the ethanolic extract with a total polyphenol concentration of 3.2 mg·mL⁻¹ demonstrated an (83.49±2.48)% inhibition rate against COX-2 activity.

CONCLUSION The macroporous resin purification technology can enhance the purity of total polyphenols from Hedyotis diffusa. It exhibits inhibitory effects on inflammation-mediated 5-LOX and COX-2, with a more pronounced inhibitory effect on COX-2.