Sea buckthorn flavonoids: Purification, identification, and in vitro anti-inflammatory effects

As the first step of resource utilization, the extraction and separation of active ingredients play an important role in the evaluation and application of their activity. In this study, a macroporous resin purification process was optimized to obtain high-purity sea buckthorn flavonoids (SBF). The AB-8 resin exhibited optimal adsorption and desorption properties, with adsorption and desorption rates of 75.25% and 84.78%, respectively. Under optimal purification conditions, the purity of the flavonoid extract was enhanced from 17.17 ± 0.19% to 63.2 ± 0.16%. Kinetic and thermodynamic analyses demonstrated that the purification of SBF on AB-8 resin conformed to the pseudo-secondary kinetic model and the Langmuir adsorption isotherm model. The major components of the SBF were taxifolin, isoquercitrin, narcissoside, and quercetin. The SBF not only inhibited lipopolysaccharide-induced nitric oxide production but also exerted significant anti-inflammatory effects, suppressing the expression of proteins such as nitric oxide synthase, tumor necrosis factor, interleukin 6, and interleukin 1β and inhibiting apoptosis. Therefore, the purified SBF demonstrated improved anti-inflammatory activity, which can be applied in the development of drugs and functional foods.