Macroporous resin purification and characterization of flavonoids from Platycladus orientalis (L.) Franco and their effects on macrophage inflammatory response

Abstract

The flavonoids (POFs) from the leaves of Platycladus orientalis (L.) Franco were purified using six different macroporous adsorption resins including polar resins NKA-9 and ADS-F8, semi-polar resins ADS-17 and AB-8, and non-polar resins D101 and ADS-5. Among semi-polar resins, AB-8 demonstrated the best adsorption and desorption capacities with an adsorption ratio of 86% and a desorption ratio of 52%. According to the Simultaneous Thermogravimetry-Differential Scanning Calorimetry (STA/TG-DSC) analysis, POFs showed three thermally decomposed temperatures (347.6 °C, 437.5 °C and 494.8 °C). The main flavonoids in POFs were identified as esculin, amentoflavone, glabridin, and afromosin. Meanwhile, POFs in the dosage range of 25 to 400 μg mL⁻¹ showed a significant anti-inflammatory effect on lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophage cells, which could inhibit the secretion of NO, IL-6, and TNF-α through the inhibition of inflammatory-related gene expressions.