In a pre-clinical, proof-of-concept study from Johns Hopkins Medicine, researchers found that epigallocatechin gallate (EGCG), a green tea compound with powerful antioxidant properties, could be promising for both treating and preventing uterine fibroids. Results of the study, first posted online May 25 in Scientific Reports, add to growing evidence that EGCG may reduce fibroid cell growth. The study was specifically designed to identify the biochemical mechanisms responsible for EGCG action in fibroid cells.
The investigators emphasize that their study involves human fibroid cells grown in the laboratory and treated with EGCG extract to explore the possibility of oral EGCG supplementation as a therapy, rather than just drinking cups of green tea as a preventative measure for uterine fibroids.
For the new study, researchers used laboratory cultures of uterine fibroids collected from living patients. Because uterine fibroid cells have a large extracellular matrix (the network of macromolecules and minerals in tissues that support, but are not part of, cells) compared to normal cells, researchers designed their experiments to see if treatment of cells with EGCG affects protein expression associated with this matrix. Specifically, they studied fibronectin, a matrix protein; cyclin D1, a protein involved with cell division; and connective tissue growth factor (CTGF) protein.
Cells were dosed with 100 micromoles (a micromole is 1 millionth of a mole) per liter of EGCG in growth media for 24 hours, and then a Western blot — a laboratory technique used to detect a specific protein in a blood or tissue sample — was performed. In this study, researchers looked for levels of cyclin D1 and CTGF proteins in EGCG-treated fibroid cells compared to untreated cells.
They found that EGCG reduced protein levels of fibronectin by 46% to 52%, compared with an untreated control group of fibroid cells. They also found that EGCG disrupted pathways involved in fibroid tumor cell growth, movement, signaling and metabolism, and they saw up to an 86% decrease in CTGF proteins compared with the control group.