Aloe-emodin is a hydroxyanthraquinone found in Aloe vera leaves that has potent laxative action by inducing chloride secretion in colonic mucosa and releasing acetylcholine, which stimulates contraction of intestinal smooth muscle. It also demonstrates anti-tumor activity (ED50s = 1-13 μM), inducing apoptosis in various cancer cells by increasing the production of reactive oxygen species. Aloe-emodin is reported to have estrogenic activity as a phytoestrogen and has been shown to inhibit breast cancer cell proliferation by downregulating ERα protein levels, and thus, suppressing transcriptional activation of the receptor.
