US researchers single out plant molecule used by Native Americans to treat pain and diarrhea
Researchers from the University of California-Irvine (UCI) have rediscovered functional uses of plant extracts collected in Muir Woods National Monument, in coastal redwood forest land in California. Plants with a long history of use by Native Americans as topical analgesics, to treat conditions such as insect bites, stings, sores and burns, were also found to have use as gastrointestinal aids – especially for preventing diarrhea.
The plants studied were found to activate KCNQ2/3 potassium channel, a protein that passes electrical impulses in the brain and other tissues. KCNQ2/3 is present in nerve cells that sense pain, and its activation would be expected to soothe pain by disfavoring transmission of the pain signal.
The same plant extracts that activate KCNQ2/3 additionally have an opposite effect on the related intestinal potassium channel, KCNQ1-KCNE3. This finding was striking as previous studies on modern medicines showed that KCNQ1-KCNE3 inhibitors can prevent diarrhea.
“Done in collaboration with the US National Parks Service, this study illustrates how much there is still to learn from the medicinal practices of Native Americans, and how, by applying molecular mechanistic approaches we can highlight their ingenuity, provide molecular rationalisations for their specific uses of plants, and potentially uncover new medicines from plants,” said Dr. Geoffrey Abbott, a professor in the Department of Physiology and Biophysics at the UCI School of Medicine.
“I personally am very excited about the paper; it was my lab’s first published collaboration with the National Park Service, and it shines a light on the incredible ingenuity and medicinal wisdom of Californian Native American tribes.”
The Abbott Lab is currently undertaking a much broader screen of native US plants toward these goals, such as treating pain and secretory diarrhea. The team have already identified compounds that explain many of the beneficial effects of the plants, and have also identified binding sites on the channel proteins that produce the effects.
With this knowledge at the molecular level of compounds that can activate versus inhibit closely related human ion channel proteins, future work can be directed at improving drug specificity and safety, while retaining efficacy.
