The Estrogenic Effect of Lysiphyllum strychnifolium (Craib) A. Schmitz Leaf Water Extract in MCF-7 Cells

Abstract

Lysiphyllum strychnifolium (Craib) A. Schmitz (LS) has been widely used as traditional medicine in the northeast region of Thailand to stimulate the production of breast milk. There are no known studies on the estrogenic action of LS on the stimulation of breast milk production. Hence, the present study aimed to investigate the estrogenic effect of LS leaf water extract compared with quercetin, one of the compounds in LS, in human breast cancer cells (MCF-7). The effect of LS leaf water extract and quercetin on cell viability of MCF-7 cells was studied by MTT assay at a concentration range of 0 to 500 µg/mL. The expression of estrogen-dependent genes, the pS2, ERα, and ERβ was also examined by real-time RT-PCR, and the expression of ERα protein was detected by Western blotting. The quercetin content in the LS water extract was 285.67 ± 0.11 µg/g of dry extract. MCF-7 cells treated with LS leaf water extract (20 µg/mL) showed an upregulation of pS2 gene expression similar to that of the treatment with E2 (10−9 M) compared with that of 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, and 20 µg/mL) decreased the phosphorylation of ERα at Ser167. LS extract (20 µg/mL) decreased ERα, but there was no significant effect on the ERα at Ser118 protein expression. This study provided scientific evidence for the potential estrogenic activities of LS leaf water extract. This indicates that ER-dependent pathways in MCF-7 cells served as mediators, facilitating the estrogenic properties of LS and its compounds to function effectively. Since LS induced pS2 gene transcription, it was confirmed that this could affect the transcription of estrogen-responsive genes, causing estrogenic effects. HIGHLIGHTSThis is the first study to demonstrate the estrogenic effect of Lysiphyllum strychnifolium leaf water extract. L. strychnifolium leaf water extract induced pS2 gene transcription, and it was confirmed that this could affect the transcription of estrogen-responsive genes which cause estrogenic effects. The results of this study support the mechanism and scientific evaluation on the use of L. strychnifolium for stimulation of breast milk in folk medicine. GRAPHICAL ABSTRACT