Spectrum-effect relationship between UPLC-Q-TOF-MS fingerprint and anti-AUB effect of Clinopodium chinense (Benth.) O. Kuntze

Clinopodium chinense (Benth.) O. Kuntze (C. chinense), a traditional Chinese medicine with significant astringent and hemostatic properties, is mainly used to treat abnormal uterine bleeding (AUB) with remarkable curative effect, but the active ingredients of which remain unclear. This study aimed to screen and identify the main antiAUB components of C. chinense via spectrum-effect relationship analysis and experiment validation. Firstly, total extract of C. chinense (TEC) of 12 batches samples was prepared by Chinese Pharmacopoeia. The fingerprint chromatogram of TEC was established by UPLC-Q-TOF-MS. The AUB model was established by intragastric administration of mifepristone and misoprostol to pregnant rats, followed by the treatment with TEC. After drug administration lasting 7 days, metrorrhagia volume was measured, pathological changes in uterine tissue were evaluated by HE staining, the levels of TXB-2, TNF-alpha, and IL-6 were measured by ELISA. The spectrum-effect relationship was investigated by grey relational analysis (GRA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Finally, the potential active ingredients of TEC screened by spectrum-effect relationship analysis were subsequently verified both in vitro and in vivo. A total of 25 common peaks were obtained from the fingerprint chromatogram of the 12 bathes TEC samples, 12 peaks were identified according to the reference substances. Comparing with the model group, TEC significantly reduced the uterine bleeding volume, alleviated endometrial injury, increased plasma TXB2 level, and decreased plasma IL-6 and TNF-alpha levels. Furthermore, seven components including kaempferol, quercetin, buddlejasaponin IVb, hesperidin, naringenin, apigenin, and saikosaponin a were identified via spectrum-effect relationship analysis. In vitro and in vivo verification indicated that buddlejasaponin IVb, hesperidin, naringenin, apigenin, and saikosaponin a were responsible for the antiAUB activity of TEC. In conclusion, the present study established a spectrum-effect relationship for C. chinense and identified the main anti-AUB compounds in TEC, which provides insight for the exploration of bioactive components and quality control of C. chinense.