Paeoniflorin

Standard compounds of albiflorin, paeoniflorin, ferulic acid, senkyunolide I, quercetin, isoliquiritigenin, atractylenolide III, ligustilide, atractylenolide II, liquiritin, liquiritigenin, saikosaponin c, glycyrrhizic acid, saikosaponin a and naringenin as an internal standard (IS) (≥98% purity) were purchased from Chengdu Herbpurify Co., Ltd. (Chengdu, China). The structures of these compounds are shown in Figure 3.
Acetonitrile (HPLC grade) was purchased from Fisher (Fair Lawn, NJ, USA). Ultrapure water with a sensitivity of 18.2 W was prepared from a Milli-Q water purification system (Millipore, Billerica, MA, USA). All other chemicals were analytical grade.

Forty-eight SD rats (PCOS group, n=48) were given subcutaneous injection of 60 mg/kg/d dehydroepiandrosterone (DHEA; APExBIO Technology LLC, Houston, USA) diluted with 0.2 ml soybean for 35 consecutive days [19 (link), 26 (link)]. The remaining rats (SDR group, n=10) were subcutaneously injected by 0.2 ml soybean oil (Shanghai Yuanye Biological Technology Co., LTD, Shanghai, China) per day. PCOS rats model was successfully established when irregular estrus cycle happened on rats. Ten PCOS rats were treated as PCOSR group (n=10), and thirty PCOS rats were divided into three groups (n=10) being administrated by gavage with Paeoniflorin (Chengdu Herbpurify Co., Ltd, Chengdu, China) on 20 mg/kg/d, 40 mg/kg/d, 80 mg/kg/d respectively [12 (link)]. Rats in SDR and PCOSR groups were treated with the same weight-based volume of distilled water by gavage for 4 weeks. All animals were euthanized under ether narcotization, and the specimens were collected for the following examinations.

Paeoniflorin, baicalin, scutellarein, liquiritigenin, baicalein, glycyrrhizic acid, wogonin, and oroxylin A were purchased from Chengdu Herbpurify Co., Ltd. (Sichuan, China). glycyrrhizic acid ammonium salt and norwogonin were purchased from ChemFaces (China). All other reagents and solvents were of high performance liquid chromatography (HPLC) grade. Deionized water was purified using a Milli-Q system (Millipore, Bedford, MA, United States). Scutellaria baicalensis Georgi (Hebei Province), Glycyrrhiza uralensis Fisch (Inner Mongolia of China), Paeonia lactiflora Pall (Anhui Province), and Ziziphus jujuba Mill (Henan Province) were authenticated by Dr. Ehu Liu (State Key Laboratory of Natural Medicines, China Pharmaceutical University, China).