Camptotheca, which has the nicknames Happy Tree, Cancer Tree, and Tree of Life, is a tree which can grow over 60 feet tall and is indigenous to Southern China and Tibet. The leaves, bark, and fruit of Camptotheca have been used in China since ancient days to cure a variety of diseases, including Cancer. Ultimately, scientists isolated Camptotheca’s primary alkaloid, Camptothecin, and found that it has powerful anti-Cancer effects, and eventually derivatives of Camptothecin became approved Cancer drugs.

The mechanism behind Camptothecin’s anti-Cancer effects is that it inhibits topoisomerase I, which is required for DNA replication. Essentially, Camptothecin stops DNA replication in Cancer cells via breaking apart the DNA, leading to apoptosis, i.e. programmed cell death. This is the critical point since Cancer is a result of apoptosis failing to occur on schedule, and Camptothecin basically restarts apoptosis, so that the Cancer cells die instead of continuing to multiply.

Another way of explaining Camptothecin’s mechanism of action is that it stabilizes the covalent bond between topoisomerase I and the 3′-phosphate group in the DNA backbone. This inhibits the re-ligation reaction catalyzed by topoisomerase I, leading to multiple DNA breaks. Additionally, Camptothecin inhibits DNA and RNA synthesis, arresting cells in the G2 phase of the cell cycle.

Although natural products from the Camptotheca tree have been used for thousands of years to treat diseases, scientists eventually created synthetic derivatives of Camptothecin, leading to multiple new Cancer drugs. The reason scientists did this was because they claimed Camptothecin in its natural form had low solubility and low bioavailability, and could be made less toxic via reformulations.

It could perhaps be speculated that scientists were pushed to make synthetic derivatives of Camptothecin, because Camptotheca and Camptothecin cannot be patented since it is a plant, and only synthetic derivatives can be patented. Indeed, patenting makes all the difference as to whether a pharmaceutical company can make money on a drug.

This speculation is perhaps affirmed by the fact that Camptotheca was found to have no significant side effects in some clinical trials which used natural products from the plant itself.

In any case, Camptothecin derivatives include Irinotecan, which is used for Colon Cancer and Small Cell Lung Cancer, Topotecan, which is used for Ovarian Cancer and Lung Cancer, and Rubitecan, which is used for Pancreatic Cancer and other solid tumors.

Overall, Camptotheca is a case example of how a natural plant that is used in traditional medicine for treating Cancer can move through the research and clinical trials process and become an approved Cancer medicine. However, Camptotheca is also an example of how a natural plant has little to no chance of being approved as a Cancer treatment. Indeed, regulators approved synthetic derivatives of Camptothecin for Cancer treatment, rather than Camptotheca and Camptothecin itself. Scientists claim that this is because the natural plant has too many side effects and is not soluble enough, although there is plenty of reason to speculate that the real reason is that Big Pharma cannot make any money on a natural plant that can help fight Cancer, since they cannot patent it, so they instead choose to make expensive synthetic derivatives.

That being said, Camptotheca is legal to use, and theoretically if you find it you are allowed to use it, although anyone who goes that route needs to do intensive research to find the preparation method, understand the dosages, and figure out the optimal way of taking it, and to investigate if it interacts with any other medications they are taking.