Background: Excessive production and/or reduced excretion of uric acid could lead to hyperuricemia, which could be a major cause of disability. Hyperuricemia has received increasing attention in the last few decades due to its global prevalence. Cichorium intybus L., commonly known as chicory, is a perennial herb of the asteraceae family. It was previously shown to exert potent hypouricemic effects linked with decreasing uric acid formation in the liver by down-regulating the activity of xanthine oxidase, and increasing uric acid excretion by up-regulating the renal OAT3 mRNA expression. The present study aimed to evaluate its extra-renal excretion and possible molecular mechanism underlying the transporter responsible for intestinal uric acid excretion in vivo. Methods: Chicory was administered intragastrically to hyperuricemic rats induced by drinking 10% fructose water. The uricosuric effect was evaluated by determining the serum uric acid level as well as the intestinal uric acid excretion by HPLC. The location and expression levels of ATP-binding cassette transporter, sub-family G, member 2 (ABCG2) in jejunum and ileum were analyzed. Results: The administration of chicory decreased the serum uric acid level significantly and increased the intestinal uric acid excretion obviously in hyperuricemic rats induced by 10% fructose drinking. Staining showed that ABCG2 was expressed in the apical membrane of the epithelium and glands of the jejunum and ileum in rats. Further examination showed that chicory enhanced the mRNA and protein expressions of ABCG2 markedly in a dose-dependent manner in jejunum and ileum. Conclusion: These findings indicate that chicory increases uric acid excretion by intestines, which may be related to the stimulation of intestinal uric acid excretion via up-regulating the mRNA and protein expressions of ABCG2.

Clerodendranthus Spicatus is a traditional Dais medi-edible plant and it has been proven to have good blood glucose-lowering efficacy. However, the material basis of Clerodendranthus Spicatus has not been clarified yet and therefore needs to be determined. In this paper, the effective ingredients of this medicine were purified by high-speed counter-current chromatography. Alongside, their potential hypoglycemic activity was determined by α-glucosidase inhibitory activities in vitro and molecular docking. Finally, five compounds were purified and identified as 2-caffeoyl-L-tartaric acid (1), N-(E)-caffeoyldopamine (2), rosmarinc acid (3), methyl rosmarinate (4), 6,7,8,3′,4′-Pentamethoxyflavone (5). Examination of α-glucosidase inhibitory activity in vitro showed that 2-caffeoyl-L-tartaric acid and rosmarinic acid had a higher inhibitory activity than acarbose. Molecular docking indicated that the affinity energy of the identified compounds ranged from − 7.6 to − 8.6 kcal/mol, a more desirable result than acarbose (− 6.6 kcal/mol). Particularly, rosmarinc acid with the lowest affinity energy of − 8.6 kcal/mol was wrapped with 6 hydrogen bonds. Overall, α-glucosidase inhibitory activities and molecular docking suggested that rosmarinc acid was likely to be a promising hypoglycemic drug.