Sclareol modulates the Treg intra-tumoral infiltrated cell and inhibits tumor growth in vivo.

A regulatory or suppressor T cell is functionally defined as a T cell that inhibits an immune response by influencing the activity of another cell type. On the other hand, Th1 cells express IFN-gamma and mediate cellular immunity. Sclareol exhibits growth inhibition and cytotoxic activity against a variety of human cancer cell lines. In the first set of experiments, Sclareol was isolated from the plant Salvia sclarea and our study assessed the immuno-therapeutic effectiveness of Sclareol by direct intra-tumoral injection. Secondly, several immunological parameters such as splenocytes proliferation, intra-tumor CD4+CD25+Foxp3+ Treg cells, IFN-gamma and IL-4 secretion and tumor size were assessed to evaluate the anti-tumoral immune response. By all means, the findings confirmed that the activity of Sclareol could reduce the tumor growth in vivo against breast cancer. Copyright (c) 2010. Published by Elsevier Inc.