Characterization and anti-uterine tumor effect of extract from Prunella vulgaris L

Background: The flowers and dried fruit spikes of Prunella vulgaris L. (P. vulgaris L.) have been widely used in traditional Chinese medicine and food. P. vulgaris L. is regarded as a good option for treating uterine myoma (UM). However, scientific evidence of anti-UM activity of the extract of P. vulgaris L. (PVE) is lacking. The present study aimed to characterize the chemical composition of PVE and evaluate the pharmacodynamics and mechanism of PVE against UM.

Methods: The chemical composition of PVE was analyzed by GC-MS. MTT was used to screen and evaluate cell proliferation and toxicity. Double fluorescence flow cytometry method were used to determine the apoptosis and cell cycle progression of UM cells under PVE treatment. The anti-UM activity of PVE was investigated by using a specific-pathogen-free (SPF) rat model of UM. TUNEL staining was used to detect the apoptosis of UM cells. The concentrations of estrogen and progesterone in the serum of SPF rats were detected by ELISA. The expression levels of PCNA, estrogen receptor alpha, estrogen receptor beta, progesterone receptor, survivin, caspase-3, Bax and Bcl-2 in the uterus of SPF rats was detected by immunohistochemistry (IHC).

Results: The extraction rate of PVE was 8.1%. The main components were squalene (28.3%), linoleic acid (9.96%), linolenic acid (9.95%), stearic acid (6.26%) and oleic acid (5.51%). In vitro, PVE had significant anti-human UM cell activity, exhibited no drug toxicity, promoted the apoptosis of human UM cells, and inhibited the transition of UM cells from the G0/G1 stage into the G2 stage, in which DNA replication occurs. In vivo, PVE had significant anti-UM activity. PVE decreased the concentrations of estrogen and progesterone and downregulated the expression levels of the estrogen and progesterone receptors through the estrogen signaling pathway. PVE also promoted the apoptosis of UM cells by downregulating the expression levels of the survivin and Bcl-2 proteins and upregulating the expression levels of caspase-3 and Bax through the mitochondria-mediated apoptotic pathway.

Conclusion: PVE has marked anti-UM activity. PVE can be used as an ideal candidate drug to treat UM.

Keywords: Apoptosis; GC-MS; Prunella vulgaris L.; Uterine Myoma.