The estrogenic effect of Lysiphyllum strychnifolium (Craib) A. Schmitz water extracts in MCF-7 cells

Abstract

Background Lysiphyllum strychnifolium (Craib) A. Schmitz (LS) has been used to stimulate breast milk production in women after giving birth in the Northeast of Thailand. However, very little information is known about its estrogenic effect. The present study investigated the estrogenic effect of LS leaves water extracts compared with quercetin, one of the major compounds in LS, in MCF7 human breast cancer cells Methods The effect of LS leaves water extracts and quercetin on cell proliferation of estrogen receptor (ER)-positive breast cancer cells, MCF-7, was studied by MTT assay at a concentration range of 0 to 500 µg/ml. The expression of estrogen-dependent genes, the pS2, ERα, ERβ and Bcl-xL, were also examined by real time RT-PCR, and the expression of ERα protein was detected by Western blotting. Results The quercetin content in LS water extract was 285.67 ± 0.11 ug/g. The expression levels of the pS2 and Bcl-xL genes in MCF-7 cells were found to be upregulated by LS leaves water extract (20 µg/ml) and 17β-estradiol (E2) (10− 5 M) compared with the untreated control. The ERα gene expression was found to be upregulated by quercetin (0.16 µg/ml) and E2 (10− 5 M) compared with the untreated control. In addition, quercetin (0.16 µg/ml) and LS extract (0.8, 4, 20 µg/ml) decreased the phosphorylation of ERα at Ser167 (pERα (ser167)) and LS extract (20 µg/ml) decreased ERα, but there was no significant effect on the ERα at Ser118 (pERα (ser 118)) protein expression. Conclusions This study provided evidence for the potential estrogenic activities of LS leaves water extract. Since LS extract induced pS2 gene transcription, it was confirmed that the extract could affect the transcription of estrogen responsive genes causing estrogenic effects. The results also showed that quercetin, one of the LS compounds, upregulated ERα gene expression at 24-hour treatment.