Common antibacterial and antifungal ingredient used in tooth paste may protect against skin cancer

A common antibacterial and antifungal ingredient used in mouthwashes and tooth paste may have another positive medicinal use: protection against skin cancer.

According to new studies, sanguinarine was shown to enhance production of proteins that induce cell death, or apoptosis, in cells damaged by ultraviolet-B (UVB) radiation. The alkaloid also restricts skin cell production of other pro-proliferation proteins. "This natural compound may protect skin from cells that acquire the genetic damage caused by UV radiation from advancing toward cancer," said Nihal Ahmad, assistant professor, Department of Dermatology, the University of Wisconsin, Madison.

"It is conceivable that sanguinarine may be used as a chemopreventive agent against skin cancer when used topically, supplemented with a sun screen."

Ahmad studies with sanguinarine were presented at the Third Annual American Association for Cancer Research International Conference on Frontiers in Cancer Prevention Research held here from October 16-20. Sanguinarine is an alkaloid present in the bloodroot plant, and is considered to have anti-bacterial, antifungal and anti-inflammatory properties. Sanguinarine is used widely in toothpastes and mouthwashes for the prevention of inflammatory conditions such as gingivitis.

Skin cell that were pretreated with sanguinarine and then exposed to UVB increased synthesis of the Bax protein and decreased production of Bcl-2, shifting cellular balance toward engineering apoptosis of the skin cells. Sanguinarine amplified the normal apoptotic response of skin cells exposed to UVB. UVB induced a 31-46 percent decrease in cell viability, and a 49-66 percent increase in the number of cells entering apoptosis. By pre-treating the cells with a low concentration (50 nM) of sanguinarine, Ahmad and his associates observed that the natural plant-based anti-oxidant agent induced a 54-72 percent decrease in cell viability after UVB. The rate of apoptosis increased an additional 49-66 percent after sanguinarine treatment prior to UVB irradiation.

By itself, sanguinarine had no effect on skin cell viability, apoptosis, or cell cycle distribution.