Sage Advice Blog

Honokiol: The Case of the Escaping Cancer Cell

November 17, 2017

Alex Speers ND, MS


Honokiol is a plant compound found in the stem and bark of Magnolia officinalis, a tree native to China that has a long history of use in traditional Chinese medicine. Honokiol has recently become popular as an anti-cancer supplement based on several cell and animal studies that have shown positive effects of honokiol against a wide range of cancer types. For example, in one animal study, mice with lung cancer were given either radiation alone or radiation with honokiol. Mice in the honokiol group saw a significantly greater reduction in tumor size (78%) compared to mice who only received radiation (42%). Research into honokiol’s anti-cancer effects has produced promising results with several other cancer types as well, including breast, ovarian, prostate, colorectal, stomach, skin, and pancreatic cancers. Most recently, honokiol has been investigated as a potential new therapy for stopping the spread of bladder cancer.


Bladder cancer is the fourth most common type of cancer among men in the United States, with men being four times more likely than women to develop the disease. While most cases of bladder cancer have a good prognosis (77.3% of patients are alive five years after diagnosis), the disease is significantly more dangerous once the cancer has spread (or metastasized) beyond the bladder. Currently, only 5% of patients with metastatic bladder cancer are alive five years after their initial diagnosis. Stopping the spread of bladder cancer, therefore, is an important goal for cancer researchers. To understand how a plant like honokiol could potentially help to achieve this goal, it’s first important to explain a few basics about how cancer spreads in our body.  


The epithelial-to-mesenchymal transition (EMT) is the name given to the complex process by which cancer cells develop the characteristics necessary to escape their local environment and travel to distant parts of the body. As one part of this process, cancer cells need to free themselves from surrounding cells so that they can escape. Normally, our cells are closely linked together with the help of a molecule named E-cadherin. E-cadherin is like a piece of Velcro, located on the surface of our cells, that can stick to other E-cadherin Velcro strips on other cells. When stuck together, E-cadherin keeps our cells organized in space, preventing any one cell from getting out of line. In the setting of cancer however, tumor cells purposely stop producing E-cadherin, making it easier for them to slip away from neighboring cells. It is much more difficult for our body to hold cancer cells in check when there’s nothing to hold onto!


A recent cell study published in Oncology Letters found that when bladder cancer cells were exposed to honokiol, the cancer cells began producing more E-cadherin, meaning more Velcro strips available to hold cells together. In addition, researchers found that honokiol decreased the expression of several cancer-promoting genes thought to be directly involved in metastasis. As a result, the spread of bladder cancer cells in this study decreased by 92%. Given how deadly bladder cancer can be once it has spread, this study offers promising evidence for honokiol to play a potential role in the treatment of this disease. It is important to note that this study was performed on cells in a lab and therefore, we cannot be sure that these effects would be seen in a human population. The pre-clinical evidence we do have however suggests that Honokiol has anti-cancer effects for a wide range of cancer types and deserves to be studied further. 


Shen L, Zhang F, Huang R, Yan J, Shen B. Honokiol inhibits bladder cancer cell invasion through repressing SRC-3 expression and epithelial-mesenchymal transition. Oncol Lett. 2017;14(4):4294-4300.


DISCLAIMER: These statements have not been evaluated by the Food and Drug Administration. There are no financial ties to any supplement companies, pharmaceutical companies, or to any of the products mentioned in this post. This post is not meant to treat, cure, prevent, or diagnose conditions or diseases and is meant for educational purposes. As always, please consult your doctor before trying any new treatments or supplements.

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