Activating Brown Fat To Lose Weight

A study in mice shows that a compound in traditional Chinese medicine could help weight loss by activating brown fat.

AsianScientist (Nov. 27, 2014) – A compound isolated from a Chinese medicinal plant could help fight obesity by increasing the conversion of fat to heat. This research has been published in Nature Communications.

Obesity is reaching epidemic proportions worldwide, leading to a rise in associated diseases such as Type 2 diabetes and cardiovascular diseases. Obesity develops when energy intake exceeds energy expenditure; approaches to managing obesity therefore either focus on reducing energy intake through dietary restrictions, or increasing energy expenditure through exercise.

“In humans, brown adipose tissue was thought to function primarily in newborn babies as a mechanism for adapting to a cold environment. Recent studies have revealed that adult humans also have functional brown adipose tissue, a finding that has fueled speculation that the pharmacologic enhancement of brown adipose tissue might be a useful strategy and a hopeful target for counteracting obesity,” Shanghai Jiatong University’s Professor Guang Ning told Asian Scientist Magazine.

In the present study, Ning and his team have found that berberine supplements could be an alternative method of increasing energy expenditure. A plant alkaloid present in many traditional Chinese herbs, berberine is commonly used to treat diarrhea but has recently also been shown to improve metabolic conditions such has insulin resistance.

When obese mice were given berberine supplements, they were protected from weight gain, had reduced free fatty acids and showed improved glucose tolerance. Berberine-treated mice also had higher body temperatures, better cold tolerance and increased energy expenditure, as determined by a comprehensive lab animal monitoring system (CLAMS).

The authors found that berberine treatment activated brown adipose tissue, the type of fat that burns lipids to produce heat. Furthermore, berberine treatment induced the conversion of white adipose tissue to brown adipose tissue, increasing the expression of the brown adipose tissue marker UCP1 at both the mRNA and protein levels.

“We found that berberine can regulate UCP1 expression by increasing PGC-1α expression and recruiting it to UCP1 promoter. We demonstrated that berberine can regulate a thermogenesis program both in brown and white adipose tissue and these effects are AMPK/PGC-1α dependent,” Ning said.

However, the effect of berberine appears to be temperature dependent. When mice were treated at 30°C rather than 22°C, they had significantly less weight reduction.

“Previous research showed that mice no longer require thermogenesis to maintain body temperature at temperatures of about 30°C, a condition known as thermoneutrality. Under such conditions, brown adipose tissue function is downregulated,” explained Ning.

“When we assessed the metabolic rates by measuring the VO2, the results clearly showed that thermoneutrality could prevent the berberine-induced increase in brown adipose tissue activity and cold tolerance. Many genes related to the thermogenic program in brown and beige adipocytes decreased markedly mice treated with berberine at 30℃.”

“Taken together, these results suggest the indispensable role of active brown adipose tissue in the berberine-increased thermogenic program,” he said.

Although the results suggest that berberine-induced activation of brown adipose tissue is a promising way of treating obesity, Ning cautions that further work is required.

“Berberine has been reported to regulate intestinal bacteria. However, in order to study the direct effects of berberine rather than its effect via modulation of intestinal bacteria, we gave the mice berberine via an intraperitoneal injection. This mode of administration is not possible with human subjects, so it remains to be seen whether berberine will have the same effects on brown adipose tissue when administered orally,” he said.

The article can be found at: Zhang et al. (2014) ​Berberine Activates Thermogenesis in White and Brown Adipose Tissue.

—–

Copyright: Asian Scientist Magazine; Photo: Ning Guang/Shanghai Jiaotong University.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Rebecca did her PhD at the National University of Singapore where she studied how macrophages integrate multiple signals from the toll-like receptor system. She was formerly the editor-in-chief of Asian Scientist Magazine.

Related Stories from Asian Scientist