Biological Actions of Oligomeric Procyanidins: Proliferation of Epithelial Cells and Hair Follicle Growth

The document discusses the importance of mesenchymal-epithelial interactions in hair growth, particularly in stimulating stem cells to proliferate and induce the anagen phase of the hair cycle, which is crucial for hair production. It is suggested that hair growth stimulants work by prolonging the anagen phase or promoting the proliferation of hair epithelial cells. The paper also mentions various in vitro and in vivo methods for evaluating hair growth stimulants, including tissue and organ culture methods, as well as animal models involving mice, rabbits, and macaques. However, the exact locations of stem cells in the hair follicle have not been definitively identified. The document is focused on the biological actions of oligomeric procyanidins on the proliferation of epithelial cells and hair follicle growth, but specific findings or conclusions regarding these compounds are not provided in the summary.