A lack of scientific evidence has led some to question whether herbs used in traditional Chinese medicines actually relieve people's ailments or if their remedial properties are mostly myth.
However, a new study, published Friday (Oct. 27) in the journal Science Advances, might start to challenge that view. Scientists have developed a new tool that they say could be used to predict the effectiveness of these herbs, and they've begun to validate some of its predictions using clinical data from almost 2,000 patients treated in a traditional Chinese medicine (TCM) hospital.
"To our knowledge, this is the first scientific theory to explain how a traditional medicine system works," lead study author Xiao Gan, a researcher at the Nanjing University of Information Science and Technology in China, told Live Science in an email.
The authors hope that, one day, their tool will be used to develop new treatments for a wide range of diseases. But it's too early to use these findings in clinical practice, experts told Live Science.
"From my quick glance at the figures, the authors found promising though somewhat weak correlations predicting herb effectiveness in treating specific symptoms," said Hakima Amri, a professor of physiology and biochemistry at Georgetown University Medical Center who was not involved in the research. "Hopefully applying this methodology to larger datasets will refine and strengthen these findings," she told Live Science in an email.
Like other types of TCM, such as acupuncture and tai chi, herbal products have been used for thousands of years to help treat and prevent disease. The medicinal usefulness of some of these herbs has been scientifically validated; for example, artemisinin, the active ingredient of the herb qinghao (Artemisia annua), known as sweet wormwood in English, is a powerful malaria drug. However, studies evaluating TCM herbs' effectiveness for treating other conditions — including stroke, heart disease and mental disorders — have been inconclusive.
In the new study, the authors looked at genes thought to be responsible for causing specific symptoms of disease, such as fever, insomnia or poor appetite. For this, they relied on an already published dataset that connected the dots between disease symptoms and the underlying genes and proteins that give rise to those ailments.
They focused on 174 symptoms that were collectively connected to at least 20 genes and then mapped these symptom-gene relationships onto a model that detailed how 18,505 proteins in the human body interact with one another. They also incorporated data on body-made proteins that are reportedly targeted by more than 1,200 TCM herbs, such as Huang Bai (Phellodendri cortex) and Chuanwu (Aconitum radix), which are used to treat fever and pain, respectively. For this, they pulled from existing databases that compiled evidence on TCM herbs' potential targets and their chemical structures.
By pulling this data together, the researchers were able to score how well these herbs might relieve specific symptoms of disease. These scores were based on how close the herbs' target proteins were to the proteins associated with various symptoms.
The authors then compared their predictions to herbs recognized by the Chinese Pharmacopoeia, an official guideline for TCM practice, as effective against specific disease symptoms. They also used the model to review prescriptions that patients at the Hubei Provincial Hospital of Traditional Chinese Medicine in Wuhan received while being treated for liver disease. This involved reviewing the herb combinations more than 1,900 patients received, seeing how their symptoms changed as a result and stacking that against the model's predictions.
Gan said that the herbs that they identified as effective from these two data sources supported their model's predictions. The authors also used their model to identify potential new applications for the herbs, beyond what's already recommended by the Chinese Pharmacopoeia.
However, Gan told Live Science that there is still a lot of work to be done before this research can be translated into clinical practice.
"This work is primarily observational and theoretical science, rather than translational science, which needs to be further validated and optimized," he said. While his team has uncovered some generic scientific principles of TCM, they're still a long way from understanding how every TCM herb works and using this knowledge to improve medical practice, he said.
"While it is interesting to translate the traditional thought processes into analytical models more well understood by western medicine, and it draws upon both expert opinion and inpatient data from a traditional Chinese medicine hospital, the model is not meant to demonstrate effectiveness for each individual herb," Marilyn Hill, an ambulatory pharmacy manager at Dartmouth Hitchcock Medical Center who was not involved in the research, told Live Science in an email.
"The statistical analysis required for such a conclusion to be made requires more complex computations than the simple binary model employed to build their theory," she said. In other words, rather than digging into the nuances of each hospital patient's response to the herbs or the combination of herbs used, the team categorized each individual herb's effectiveness as "true or false" based on the percentage of people whose symptoms abated after they were given a certain herb.
Hill did, however, acknowledge that it can be difficult to study TCM herbs considering how varied the natural products can be and how hard it is to isolate the effects of specific chemicals within them. Testing natural products in clinical trials can also be costly, so it is helpful to use computer simulations to identify potential drug targets, Xiang-Qun Xie, a professor of pharmaceutical sciences at the University of Pittsburgh who was not involved in the research, told Live Science.
Xie said more data are needed to support these findings and that it would be useful to study how TCM herbs and modern medications may interact in patients who take them simultaneously.
In the meantime, "while their model may be helpful to identify future areas of research, it does not change the current understanding of herb efficacy," Hill said.
"It’s important to also remember that herbs and supplements are still drugs, and patients should feel empowered to share what they are taking with all healthcare providers, as there could be significant interactions," she added.
This article is for informational purposes only and is not meant to offer medical advice.
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Emily is a health news writer based in London, United Kingdom. She holds a bachelor's degree in biology from Durham University and a master's degree in clinical and therapeutic neuroscience from Oxford University. She has worked in science communication, medical writing and as a local news reporter while undertaking journalism training. In 2018, she was named one of MHP Communications' 30 journalists to watch under 30. (email@example.com)