Effect of letrozole and raloxifene on in vitro human endometrial stromal cells

Letrozole and raloxifene are used in female reproductive disease. They have special properties and side-effects. This study was performed with aim to compare the in vitro effects of letrozole and raloxifene on human endometrial stromal cells.

This experimental study was performed in 2019 on 16 samples of endometrial biopsy of women with normal menstrual cycles in secretory phase. Endometrial biopsies were digested by collagenase type I. Stromal cells were harvested by using serial filtration of cell suspension through cell strainer (70 and 40 µm) and ficoll layering. The cells were confirmed by immunohistochemical staining for vimentin. The cells of each biopsy were divided into: control and letrozole, or control and raloxifene. After 15 day, morphological changes and cell viability were determined. Data were analyzed by one way ANOVA and Tukey test.

Cell viability in control and letrozole 0.1, 1 and 10 µM concentration was 14.7, 7.8, 5.6 and 4.2 ×104 cells, respectively. Cell viability in control and raloxifene 0.1, 1 and 10 µM was 21.8, 12.9, 9.1 and 3×104 cells, respectively; the difference was significant (P<0.05). The morphological changes score of cells were 3.86, 3.38, 2.68 and 2.08 in control and letrozole groups, and were 3.98, 3.77, 3.72, 1.18 in control and raloxifene; the difference was significant (P<0.05). The effect of letrozole and raloxifene on the bioavailability and morphology of endometrial stromal cells was different.

Letrozole and raloxifene showed anti-proliferative and dose-dependent effects on in vitro human endometrial stromal cells and raloxifene effect was more potent than letrozole.