An extract of the "thunder god vine" that has been used in Chinese medicine throughout history could be an effective treatment for obesity.

Researchers found the extract caused up to a 45 percent decrease in body weight in obese mice and greatly reduced appetite, Cell Press reported. The medicine is believed to work because it contains the weight-loss compound Celastro, which boosts the appetite-suppressing hormone leptin.

"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," said senior study author Umut Ozcan, an endocrinologist at Boston Children's Hospital and Harvard Medical School. "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."

Humans and mice that lack leptin have insatiable appetites that cause obesity, suggesting leptin-enhancing drugs such as what could be developed from Celastro have the potential to fight obesity. In the past, the research team found that leptin resistance was linked to a stress response in a cell structure called the endoplasmic reticulum (ER). In this recent study, the researchers looked at a database of whole-genome gene expression profiles from human cells that were treated with more than 1,000 molecules. The data suggested Celastrol was extremely effective at producing an expression profile that could potentially improve ER function and even leptin sensitivity.

Obese mice that were treated with Celastrol were observed to reduce their food intake by approximately 80 percent when compared with the untreated mice and had effectively reduced their body weight by an impressive 45 percent three weeks later. The weight loss was greater than what would be seen with bariatric surgery, and the treatment even improved cholesterol levels, metabolism and liver function.

The researchers warn that although no toxic effects were seen in the mice, further studies are required to test the safety of the potential treatment.

"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," Ozcan said. "As a result, it could be dangerous for humans to consume thunder god vine extracts to lose weight."

The findings were published in a recent edition of the journal Cell.