An Australian research team has found that mice fed a high-fat diet plus a new drug reduced weight gain by 40%.
The scientists examined a nerve signalling molecule neuropeptide Y (NPY) which helps animals survive conditions when food shortages are common by turning ‘energy-storing’ fat into ‘energy-burning’ fat – hence reducing heat-boosting food intake and reducing energy output.
The team investigated the effect of a drug called BIBO3304 on mice and human fat cells from people with obesity and found it blocks a receptor for NPY and increases heat generation in fat tissue.
In addition, the drug does not cross the ‘blood-brain barrier’ – so unlike other weight loss drugs ‘it is unlikely to adversely affect mood’ Previously, various drugs that suppress appetite (by acting directly on neuro-transmitter systems in the brain) have been withdrawn due to adverse effects involving mood an heart function.
The team led by Dr Yanchuan Shi and Professor Herbert Herzog at Sydney’s Garvan Institute of Medical Research tested a new way of reducing weight gain without affecting the central nervous system.
Their research project, published in Nature Communications, fed mice a high-fat diet for 7 weeks with or without BIBO3304.
Those given the drug gained 40% less weight and Dr Shi noted ‘blocking the receptor in fat tissues transformed the energy-storing fat into energy-burning fat, which switched on heat production and reduced weight gain’.
When the researchers applied BIBO3304 to fat cells from people with obesity, the cells ‘switched on the same genes involved in heat generation as those activated in the mice’.
However, Professor Keith Frayn at Oxford University in the UK warned metabolism in mice and humans differs in important ways and told medicalnewstoday.com: ‘Small rodents have a much greater capacity than humans for upregulating thermogenesis (increasing heat generation). So we cannot assume these studies in mice will translate to humans until they are rested.’
