Anti-cancer effects of EGCG

Epigallocatechin gallate (EGCG) is a type of catechin isolated from green tea. EGCG has been reported to induce antiproliferative and apoptotic efects in uterine leiomyoma cells2325. In addition, the therapeutic efects of EGCG have been demonstrated in animal models. Female athymic nude mice were given 1.25 mg EGCG/day (in drinking water) for 4 and 8 weeks25. Results showed that EGCG treatment signifcantly reduced the volume and weight of tumor.

EGCG treatment (200 or 400 mg of EGCG/kg of diet) also signifcantly reduced the size and number of leiomyomas of the oviduct in Japanese quail afer 12 months26. In a randomized controlled pilot clinical trial, women with symptomatic fbroids were given green tea extract (45% EGCG) (800 mg/day) for 4 months27. Results showed that EGCG reduced fbroid volume by 32.6% and reduced specifc symptom severity by 32.4%, compared to the placebo group27. Notably, adverse events such as endometrial hyperplasia were not observed in the EGCG treated group27 .

In a recent randomized phase I study, the hepatic safety profle of EGCG in healthy reproductive-aged women with and without fbroids was studied28. Patients were given 720 mg of EGCG alone or in combination with clomiphene citrate or letrozole for 5 days and investigators found no signs of drug induced liver injury28.

Te promising efects observed have led to clinical trials to examine the safety and efcacy of EGCG (NCT04177693; NCT05409872; NCT0536008). Tese observations suggest that EGCG might be a clinically safe and efective natural compound for fbroid treatment. Although EGCG appears efective, the underlying mechanisms of action on uterine fbroids have not been fully elucidated. Here, we report that EGCG induced antifbrotic efects in uterine fbroid cells. EGCG altered multiple signaling pathways involved in mediating fbrosis in uterine fbroid cells, suggesting the possibility of combination treatments for fbroid therapy.