Obesity is a complex disease, and consequently tackling it is often not as simple as advising lifestyle changes, such as exercising more and reducing calorie intake. While surgical interventions like gastric bands are effective, they’re expensive and extreme options; an effective diet drug would certainly find a place in modern medicine. A few potentials have surfaced recently, and it seems that scientists could have just stumbled upon another: Thunder god vine.
Rather impressively, extracts from this plant caused obese mice to reduce the amount they ate and led to weight losses of up to 45%. This was achieved by increasing their sensitivity to a hormone called leptin, a signaling molecule that acts as a mediator of energy balance regulation and suppresses food intake and appetite, thus inducing weight loss. While it’s far too early to tell whether same effects will be induced in obese humans, these preliminary findings certainly warrant further research and possibly suggest that this extract could be used to develop a novel obesity treatment. The work has been published in Cell.
Ever since its discovery more than two decades ago, scientists have pondered the possibility of developing obesity treatments centered around leptin. Although humans and mice lacking its signaling overeat and become morbidly obese, hopes of its usefulness were slashed when it became apparent that high blood levels of leptin were unable to reduce eating behaviors in obese individuals. Furthermore, administering it to obese mice didn’t cause them to lose weight.
Taken together, these findings seemed to suggest that leptin insensitivity or resistance could be contributing to obesity. A significant amount of effort was therefore dedicated to finding a potential way to alleviate this resistance, but endeavors had been fruitless. However, renewed hope was offered when scientists discovered that within the brain, increased stress in a specialized structure found in the cell, called the endoplasmic reticulum (ER), played a pivotal role in the development of leptin resistance and obesity.
With this in mind, researchers from Harvard Medical School began scouring a database which contained information on how gene expression in human cells changed in response to certain drugs. After plowing through more than 1,000 entries, they found that a substance called Celastrol produced a gene expression profile which could potentially reduce ER stress. This compound is extracted from the thunder god vine, a plant native to China, Japan and Korea that has been used in traditional Chinese medicine for over 400 years.
The team then administered this compound to mice with diet-induced obesity, and the effects were surprisingly dramatic. Not only did it reduce their food intake, but it also caused them to shed 45% of their weight. Further investigation also revealed that leptin sensitivity was increased and ER stress was reduced. Taking this one step further, the researchers tested it out in mice who were engineered to be leptin deficient or lack leptin receptors. As anticipated, it was ineffective in these animals.
Although this work is promising, the researchers caution that the results should not be taken to mean that thunder god vine extracts will make you lose weight; much more work needs to be done before anything is proven. Furthermore, Celastrol is only found in tiny amounts in the roots of this plant, and other parts of it are extremely poisonous and can even cause death. But the researchers are hopeful that with further research, this study may eventually open up a novel treatment avenue for obesity.
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