Brain-signal study offers hope in obesity fight

Trials on mice by Otago University researchers suggest that butein can be used to block diet-driven processes in the brain that lead to obesity. Photo / Thinkstock

Kiwi scientists have found a curious new way to combat obesity and Type 2 Diabetes in an antioxidant linked to Chinese medicine.

Trials on mice by Otago University researchers suggest that butein, derived from plants used in traditional Chinese herbal medicine, can be used to block diet-driven processes in the brain that lead to obesity.

The study led by Dr Alex Tups, of the university's Centre for Neuroendocrinology and Department of Physiology, centred on a part of the brain called the hypothalamus, which is linked to the nervous system and helps regulate many important functions including sleep, heart rate, body temperature, appetite, and body weight. The team sought to find out whether directly stopping inflammatory processes in the hypothalamus caused by a high fat diet could help lower blood sugar levels and reduce insulin resistance.

In two types of obese mice, butein was used to block the specific signalling pathways involved in the body's inflammatory immune responses.

The approach worked, showing that administering butein either directly into the brain or orally greatly improved glucose tolerance and brain insulin signalling.

Dr Tups said the profound effect was also dose-dependent, with higher doses of butein increasing tolerance to glucose.

Interestingly, the improved tolerance in the mice given high-fat diets and treated with butein resulted in them showing no noticeable difference from the "control" mice than had not received butein nor a fatty diet.

To confirm the link between the investigated brain pathways and metabolic obesity symptoms, the researchers also used a gene therapy technique to inhibit it in neurons in the hypothalamus.

This resulted in the high-fat diet mice having a reduced body weight, building up less fat, expending more energy, and showing evidence of improved leptin-signalling.

Dr Tups said the study, published in the leading international journal Diabetes, added to growing body of evidence that a diet high in saturated fats activated a cascade of inflammatory processes in the brain which impair leptin and insulin signalling, leading to obesity and type II diabetes.

Blocking the brain to battle obesity

• An NZ-led study investigated whether particular signalling pathways in the brain could be blocked to decrease the causes of obesity and Type 2 diabetes.
• They used butein to directly stop inflammatory processes in the brain's hypothalamus caused by a high-fat diet, helping lower blood sugar levels and reduce insulin resistance.
• The approach was shown to work in obese mice. The researchers say such natural compounds that block inflammation in the brain should be "vigorously investigated" as novel anti-diabetic treatments.