Molecular Investigation of Bear Bile: A gift from Nature and Traditional Chinese Medicine to the World
Disclaimer: In presenting the scientific evidence of the use of bear bile, or its synthetic derivatives, demonstrating benefits to a range of health benefits including mental health, it does not confer that we at ITM in any way support or condone the inhumane treatment of any animals.
Dried bear bile has been utilized since before the Tang Dynasty (659 Common Era) in China as traditional medicine, and its day-to-day medical use has been implemented in Korea and Japan several centuries ago. At the beginning of the modern era, when international travel increased, the application of Traditional Chinese Medicine (TCM) spread across Asia, and then quickly circulated among Asian communities in other parts of the world, including the European Union and the United States. The majority of consumers bought bear bile medicines, as they were found in TCM pharmacies, or as a result of them regarding bear bile as a beneficial traditional medicine.
The use of bear bile is controversial and has understandably raised concerns from the public, media, and animal rights activists all over the world. There are two main concerns, the first surrounds the very high consumption of bear bile by China, and other countries, which has resulted in bears becoming an endangered species; the second is the inhumane method used to extract bile from living bears. In this blog, I will be discussing these concerns, in the context of why bear bile is a popular traditional medicine and what it brings to the world.
I am a visiting researcher at the Stress, Psychiatry and Immunology (SPI) Lab at King’s College London, and a part of the team that brings you InSPIre the Mind. I am also an Associate Professor in Shanghai University of TCM.
I have been working on the potential effect of bear bile and its active ingredients in neuropsychiatric disorders, for more than 7 years now. Together with my supervisor Dr. Alessandra Borsini, a Senior Postdoctoral Neuroscientist, we have recently written a systematic review: from dried bear bile to molecular investigation.
Let’s start with the historical use of bear bile.
From the perspective of TCM, dried bear bile (usually called bear bile powder) is categorized as ‘cold’ medicine. It is bitter in flavour and shows remarkable capabilities to clear “liver heat” and “reduce liver fire” , which can cause symptoms like “irritability, outbursts of anger, temporal headache, dizziness, red face and eyes, thirst and bitter taste”.
Dried bear bile can be dissolved in milk or plant syrup to treat febrile seizures in children. Such seizures cause “stiffness, twitching in the arms and legs, loss of consciousness”, and sometimes incontinence. In addition, bear bile powder can also be administered orally or externally to treat syndromes such as skin boils), piles and sore throat.
Also, bear bile has been widely used across East and Southeast Asia. For instance, it is generally taken by young mothers and expecting mothers in Cambodia, for symptoms considered as post-natal fatigue (named toas in Khmer, the Cambodian language), also known as post-natal depression. Apart from these traditional applications, the use of bear bile has broadly extended to the treatment of many other diseases defined by western medicine, based on modern pharmacological studies, such as inflammation, or liver cancer.
However, from a place of empathy to other living creatures, we must ask why and how it comes at a cost to individual bears’ welfare? and further, could there be an alternative?
Although bears are listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora, the illegal abuse of innocent bears for huge profits worldwide is continuing. Further, the extraction method is controversial. Over the decades, in view of these significant concerns, scientists have developed several substitutes for bear bile, such as artificial bear bile and synthetic compounds.
What does bear bile contain?
Among the numerous chemical components of bear bile, ursodeoxycholic acid (UDCA), is one of the bile acids that is considered to be a major active component. In the 1950s, it was successfully synthesized by scientists and applied in the clinical treatment of liver diseases. Currently, UDCA (the commercial name called Ursodiol) is widely used as the first-line drug for the treatment of liver diseases and the therapy was also approved by the United States Food and Drug Administration for primary biliary cirrhosis -a specific type of liver disease. Moreover, its application has been expanded to other liver diseases, like intrahepatic cholestasis of pregnancy (“a liver condition that occurs in late pregnancy”), and even to non-liver diseases, such as inflammatory bowel diseases (“long-term conditions that involve inflammation of the gut”).
During the COVID-19 pandemic, scientists have recently highlighted a clinical trial of UDCA as a preventive treatment in patients who have early symptoms in the onset of COVID-19, in addition to those who are especially at high risk with chronic diseases, such as “diabetes, obesity, cardiac and lung disease, and any immune-compromised state”. At the moment there is no results for UDCA treatment in COVID-19 just yet. The adaptability and the wider use of UDCA are due to its multiple mechanisms of action.
When administered orally, UDCA is immediately changed to form another type of bile acid named glycoursodeoxycholic acid (GUDCA) in humans, and to a lesser extent in to bile acid tauroursodeoxycholic acid (TUDCA). Various studies have now started to investigate the effect and the mechanism of UDCA, GUDCA and TUDCA in the context of neurological, neurodegenerative, and neuropsychiatric disorders.
So, what did they find out?
In laboratory studies of neurological, neurodegenerative, and neuropsychiatric disorders, all three bile acids were able to slow down the process of cell death, this is the event of a biological cell whereby the cell no longer carries out its functions. Bile acids do this by preventing damage to cells caused by free radicals (unstable molecules that the body produces as a reaction to environmental and other pressures) and also help the immune system to defend the body from harmful agents, such as bacteria. In addition, findings from these studies also suggest that all three bile acids would be equally beneficial in laboratory studies of Huntington’s disease (“a condition that stops parts of the brain working properly over time”), whereas UDCA and TUDCA would be more beneficial in models of Parkinson’s disease (“a condition in which parts of the brain become progressively damaged over many years”) and even in Alzheimer’s disease (“the most common cause of dementia”). On the other hand, the use of GUDCA would be most beneficial in models of bilirubin encephalopathy (brain damage caused by high levels of a yellowish pigment that is made during the normal breakdown of red blood cells) and TUDCA in models of depression.
What would be the next step?
As discussed, scientific research has shown that there is a wide range of opportunities for bear bile to have an application use in neurological, neurodegenerative, neuropsychiatric disorders. Future research will allow scientists to identify specific bile acids that would be most effective for each specific disorder, and ultimately to develop more personalized strategies for patients suffering from these conditions. Additionally, given its clinical safety, the three bile acids also could be given in addition to conventional medicines to improve the treatment outcomes in neurological, neurodegenerative and neuropsychiatric disorders.
But for now, I believe this is enough of a gift from nature and traditional Chinese medicine to the world!