Multi-model Evaluation of Anti-glycation Effects of Sophora japonica Flowers Aqueous Extract and Its Active Components Analysis

Objective: To investigate and analyze anti-glycation effects of the aqueous extract of Sophora japonica flower (SJF) by using different models, as well as its active constitutes identification. Methods: BSA/reducing sugar reaction system, glycosylated fibroblast induced by methylglyoxal and AGEs-increased zebrafish model triggered by glucose solution were simultaneously established to comprehensively evaluate the anti-glycation effects of SJF aqueous extract from biochemical, cellular and zebrafish aspects, respectively. Identification of major components was performed by ultra-high performance liquid chromatography-high resolution mass spectrometry technique (UPLC-Triple TOF/MS). Biochemical system was subsequently adopted to further analyze anti-glycation effects of these primary components. Results: In the BSA/reducing sugar system, IC₅₀ of AGEs inhibition of SJF aqueous extract was 53.93 μg/mL. 10 and 40 μg/mL of SJF aqueous extracts dramatically inhibited CML expressions in fibroblast model (P<0.0001), which decreased by 72.28% and 83.85%, respectively. Then, zebrafish model was also used to verify anti-glycation effects of SJF aqueous extract. When the concentration of SJF aqueous extract reached 2 mg/mL, the glycation inhibitory rate could be as high as 76.85%. Through analysis of UPLC-Triple-TOF/MS, a total of 14 chemical compounds, mainly flavonoids, were preliminarily identified. Seven compounds among them were selected for further anti-glycation evaluation by BSA/reducing sugar system. All of the seven compounds showed variable activities toward anti-AGEs production, notably, rutin, quercetin and kaempferol revealed a remarkable activity with a IC₅₀ of 165.5, 133.0 and 42.9 μmol/L, respectively, which were better than that of positive control drugs. Conclusion: SJF aqueous extract shows remarkable anti-glycation activity. Flavonoids such as rutin, quercetin and kaempferol are its potential active compounds.