A new study published online in the journal PLoS One concluded that preliminary results show that melatonin, a hormone that regulates our sleep and awake cycles, may have the potential to inhibit the growth and cell production and block the formation of new blood vessels in ER-negative breast cancer models. Researchers said “These early stage research results with the melatonin drug in a triple-negative breast cancer animal model achieved in our lab has not been seen anywhere else.”
To determine the effectiveness of of melatonin on tumor growth, researchers evaluated the action of melatonin on angiogenesis (f0rmation of new blood vessels) in ER-negative breast cancer in vitro and in vitro using cells and mouse models respectively, Mice were randomly assigned to the study or control group and the study group received treatment of melatonin one hour before lights were turned out for 21 days. The time coincided with the time that cells are most sensitive to the hormone. . At the end of the 21 nights researchers used single photon emission computed tomography (SPECT) to determine whether the melatonin therapy effectively decreased the size of the implanted human triple negative breast cancer in the mouse model and if there was any change in the formation of new blood vessels. In addition, tumor volume was measured weekly and and tumor tissue was analyzed at the end of treatment.