Changes in the profiling of bioactive components with the roasting process in Lycium chinense leaves and the anti‐obesity effect of its bioaccessible fractions

Abstract Background This study aimed to investigate the profiles of bioactive components in roasted Lycium chinense leaves (LCLs) and its in vitro anti‐obesity activity after digestion processes. Results Chlorogenic acid, kaempferol‐3‐sophoroside‐7‐glucoside, kaempferol‐3‐sophoroside, and kaempferol‐3‐glucoside were discovered as bioactive components in various ratios of ethanol (EtOH) extract in LCLs by using ultra‐performance liquid chromatography‐electrospray ionization–mass spectrophotometry (UPLC‐ESI–MS). The roasting process followed by a 30% EtOH extraction tended to decrease the content of chlorogenic acid and kaempferol‐3‐glucoside, and enhanced the content of kaempferol‐3‐sophoroside‐7‐glucoside. It effectively inhibited pancreatic lipase activity by 62.50 ± 4.81%, which was approximately 1.71 percentage points higher than that of the dried‐nonroasted LCL extract (60.79 ± 3.75%). Its bioaccessible fraction obtained from in vitro digestion significantly and dose dependently reduced intracellular lipid accumulation by adipocyte 3T3‐L1 compared with a 30% EtOH extraction. At a concentration of 200 μg mL −1 , it inhibited lipid accumulation up to 29.55% in 3T3‐L1 cells, which indicated that human digestive enzymes converted kaempferol‐3‐sophoroside‐7‐glucoside to kaempferol metabolites that have anti‐obesity effects. Conclusion This study suggests that the profiling of bioactive components by processing methods and a bioaccessible fraction could be crucial to improve the bioactivity of LCLs, and potentially be a natural anti‐obesity ingredient after oral intake. © 2019 Society of Chemical Industry