Viagra may also combat obesity: study

Researchers from the University of Bonn, who treated mice with drug, discovered the signalling pathway by which Viagra might be able to fight excess weight.

They said the drug converts undesirable white fat cells and could thus potentially melt the unwelcome "spare tire" around the midriff.

In addition, the substance also decreases the risk of other complications caused by obesity, according to the study published in the FASEB Journal.

Sildenafil - better known as Viagra - is used to treat erectile dysfunction. This substance prevents degradation of cyclic guanosine mono-phosphate (cGMP), which then ensures blood supply for an erection.

However, another effect of Viagra has been noticed quite some time ago - mice given sildenafil over longer periods of time were resistant to obesity when fed with high-fat diet.

However, the cause for this reduced weight gain had been unclear. Researchers now have been able to shed some light on this sildenafil effect.

"Sildenafil is not only able to minimise erectile problems, but it can also reduce the risks of gaining excessive weight," said Dr Alexander Pfeifer, Director of the Institute for Pharmacology and Toxicology.

The research team around studied the effect of sildenafil on fat cells in mice. They administered the potency drug to the rodents for seven days.

"The effects were quite amazing," said researcher Ana Kilic.

Sildenafil increased the conversion of white fat cells, which are found in human "problem areas" into beige ones in the animals.

"Beige fat cells burn the energy from ingested food and convert it to heat," said Pfeifer.

Because the beige fat cells can "melt the fat" and thus fight obesity, researchers are very hopeful for their potential.

The researchers also observed if white fat cells are further "stuffed" or accumulating lipids, they are increasing in size and can synthesise and release hormones which in turn cause inflammation thus increasing the persons risk for chronic diseases.

Such inflammatory responses may then lead to cardio-vascular diseases resulting in heart attacks and strokes, as well as cancer and diabetes.

"It seems that sildenafil prevented the fat cells in these mice from getting onto that slippery slope," said Pfeifer.

According to the study, over half a billion people are overweight globally.