ABSTRACT
OBJECTIVE：To provide reference for elucidating the anti-allergic asthma constituents in alkaloids-free part of Ephedrae Herba. METHODS ：Ephedrae Herba was extracted with 85％ ethanol and n-heptane，and then subjected to solid-phase extraction（filler AC 18）for pretreatment to enrich alkaloids-free part from the extract of Ephedrae Herba. HPLC method was adopted，and alkaloids-free fractions of Ephedrae Herba were performed on Unitary C 18 column and Eclipse XDB-C 18 column. Using high expression G protein coupled-receptor 35（GPR35 receptor）in HT- 29 cell as target ，GPR35 receptor agonist zaprinast （1 μmol/L）as positive control ，DMR response value as the detection index ，the agonistic and desensitizing activity of each fraction（100 μg/mL）on GPR 35 receptor was screened by label-free integrated pharmacological method ，so as to screen active anti-allergic asthma fraction. HPLC-Q-TOF-MS method was used to identify the chemical composition of the selected active fractions. RESULTS ：The alkaloids-free part of Ephedrae Herba was divided into two parts ，involving the precipitated part before solid phase extraction and the 95％ methanol elution part ；from them ，20 fractions were screened. Among them ，the precipitated fraction F 1.5-F1.10 and 95％ methanol eluted fraction F 2.5-F2.10 had a strong agonistic activity on GPR 35 receptor；at the same time，GPR35 receptor agonist zaprinast showed a relatively strong desensitization activity. The signal intensity of DMR induced by F1.5-F1.10 in the precipitated part of HT- 29 cells was even higher than that of reference drug zaprinast. By HPLC-Q-TOF-MS analysis，24 chemical components were identified from active fractions ，involving 14 flavonoids，2 volatile oils ，7 organic carboxylic acids ，1 anthraquinones. CONCLUSIONS ：The alkaloid-free part of Ephedrae Herba is mainly flavonoids and has anti-allergic asthma activity.