Plant extracts and their active compounds have been used for medicinal purposes for centuries by various traditional medical practices including Ayurveda, traditional Chinese medicine. Interestingly, some of the most common anticancer drugs like taxol, vincristine are derived from plat extracts. Unfortunately treatment of metastatic advanced cancers using adjuvant therapies (multiple compounds) leads only to a limited success, but severe side effects. We have previously demonstrated very potent anticancer activity of different plat extracts including dandelion root, lemongrass, long pepper and white tea extracts in different human cancer cells including lymphomas and leukemias. Since these extracts are safe and can be taken orally, the total extract (which is adjuvant of many compounds in itself) could be taken as supplements along with standard cancer treatments. One major hurdle is their potential interaction with standard chemotherapies and radiation therapy. Many oncologists strongly oppose taking any natural extracts as they think it could hamper the treatment of cancer patients. Therefore, it is critical to investigate drug- natural extracts interaction. Our hypothesis is that natural extracts would sensitize cancer cells to standard treatment as well as reduce toxicity related to these treatments for healthy tissue. We have demonstrated that Dandelion and Lemongrass extracts display positive interaction with different chemo regimens in colon and prostate cancer cell in vitro and in vivo. Furthermore, we have discovered that these extracts inhibit appearance of colon tumor in transgenic APC min mice indicating their preventative ability. Most of the results from our work on lymphoma and leukemia will be presented.