Possible new weapon against obesity: Chinese thunder god vine, used in traditional medicine
A plant extract widely used in traditional Chinese medicine as an anti-rheumatic drug has shown in a new study to reduce food intake, leading obese mice to lose up to 45 per cent of their body weight.
Celastrol, the extract from the roots of the thunder god vine – also known as lei gong teng or by its scientific name Tripterygium wilfordii – produces its potent effects by enhancing the action of an appetite-suppressing hormone called leptin.
The study’s researchers, from Boston’s Children Hospital and Harvard Medical School, say the findings are an early indicator that Celastrol could be developed into a drug for the treatment of obesity. The study appeared on Thursday in the journal Cell.
“During the last two decades, there has been an enormous amount of effort to treat obesity by breaking down leptin resistance, but these efforts have failed,” says senior study author and endocrinologist Umut Ozcan.
“The message from this study is that there is still hope for making leptin work, and there is still hope for treating obesity. If Celastrol works in humans as it does in mice, it could be a powerful way to treat obesity and improve the health of many patients suffering from obesity and associated complications, such as heart disease, fatty liver, and type 2 diabetes.”
Thunder god vine, which grows in southern China and is also native to Japan and Korea, has been used for centuries in China to combat rheumatoid arthritis. It’s also used as a folk remedy for excessive menstrual periods and autoimmune diseases such as multiple sclerosis and lupus.
The extract has also been shown to wipe out pancreatic tumours in mice, according to a study published in 2012 in the journal Science Translational Medicine by researchers from University of Minnesota’s Masonic Cancer Centre.
The compound’s effectiveness, however, is offset by toxicity side effects which include hair loss, diarrhoea, bone marrow suppression and infertility, according to Hong Kong University researchers who have studied the extract.
In this new study, Ozcan and his team expanded on previous research they had done on leptin resistance, which was found to be associated with a stress response in a cell structure called the endoplasmic reticulum.
Leptin, a fat-cell-derived hormone, signals to the brain when the body has enough fuel and energy. But leptin does not reduce hunger or food intake in obese individuals despite high levels of the hormone in the bloodstream, leading many researchers to speculate that leptin insensitivity is the root cause of obesity.
Ozcan and colleagues found Celastrol to be effective at producing cell activity that could be associated with improved endoplasmic reticulum function and leptin sensitivity in human cells.
Within only one week of Celastrol treatment, obese mice reduced their food intake by about 80 per cent compared to untreated obese mice. By the end of the third week, treated mice lost 45 per cent of their initial body weight almost entirely by burning fat stores.
This dramatic weight loss is greater than that produced by weight-loss surgery, say the researchers. Moreover, Celastrol decreased cholesterol levels and improved liver function and glucose metabolism, which collectively may translate into a lower risk of heart disease, fatty liver, and type 2 diabetes.
But don’t rush out to buy the thunder god vine extract just yet. Even though Celastrol did not produce toxic effects in mice, Ozcan strongly urges caution for now because in-depth toxicology studies and controlled clinical trials are needed to demonstrate the compound’s safety in humans.
“Celastrol is found in the roots of the thunder god vine in small amounts, but the plant’s roots and flowers have many other compounds,” he says. “As a result, it could be dangerous for humans to consume thunder god vine extracts to lose weight.”