OBJECTIVE: Leiomyoma, or uterine fibroid, is the most common benign gynecological neoplasm. It can cause abnormal uterine bleeding, pain, urinary incontinence, constipation and dyspareunia. Hysterectomy is the most used treatment. Currently great efforts are carried out to find alternative therapeutic strategies. Among them, vitamin D and epigallocatechin gallate administration gave promising results. We developed a rat leiomyoma model to investigate their mechanisms of action and evaluate their effects.

MATERIALS AND METHODS: Leiomyoma was induced in thirty-five female Wistar rats by diethylstilbestrol and progesterone according to a standardized animal model. Control group (no Leiomyoma) received only distilled water. Vitamin D3 and Epigallocatechin Gallate were administered orally for 3 weeks to all rats, with the exception of controls. Treatment groups: Leiomyoma + Saline, Leiomyoma + Vitamin D3, Leiomyoma + Epigallocatechin Gallate, Leiomyoma + Vitamin D3 + Epigallocatechin Gallate. The evaluation was made by histological, immunohistochemical and biochemical examination.

RESULTS: Leiomyoma rats displayed all the typical features of the pathology. Histological analysis demonstrated that the treatments allowed to reach the same condition of control rats. All parameters detected by immunohistochemical investigation (PCNA, Ki67, Bcl-2, Caspase-3, α-SMA, Type 1 Collagen, estradiol and progesterone) were found significantly increased in Leiomyoma rats respect to controls. Vitamin D and Epigallocatechin Gallate significantly reduced them all, with the exclusion of Caspase-3. Of note, their combined administration achieved a greater decrease in PCNA than both the single treatments.

CONCLUSIONS: This experimental study confirmed the therapeutic efficacy of vitamin D and Epigallocatechin Gallate, separately and together, and allowed to highlight their effects at molecular level.