A new study has reported that pterostilbene, an antioxidant found in blueberries and red grapes, inhibits leptin-stimulated growth and proliferation of breast cancer cells. The fat hormone leptin has been found to promote breast cancer growth and development in obese women. This may occur though leptin's activation of JAK/STAT3 signalling and dysregulation of apoptosis (programmed cell death).

The authors previously showed that pterostilbene inhibits proliferation and induces apoptosis in breast cancer. In the current study, the authors evaluated the effect of pterostilbene on cell proliferation and JAK/STAT3 signaling in leptin-stimulated breast cancer.

To conduct the study, human breast cancer cells were treated with leptin alone or leptin plus pterostilbene. Pterostilbene was found to suppress normal as well as leptin-induced JAK/STAT3 activation. Pterostilbene also was shown to inhibit leptin-induced cell proliferation. The authors conclude that pterostilbene has an inhibitory effect on leptin-stimulated breast cancer through reduction of cell proliferation and JAK/STAT3 signaling, a critical regulatory component of tumorigenesis in obesity-related breast cancer.