Pomegranate leaf extract may be novel appetite suppressant

"Pomegranate leaf extract may be a novel appetite suppressant that only affects obesity owing to a high-fat diet," wrote lead author Li Jun Du from Tsinghua University in Beijing.

The health-benefits of pomegranate have focussed almost exclusively on the fruit, most notably in fruit form although extracts are also gaining increasing attention.

The antioxidant-rich fruit have been linked to improved heart health, and claims that it may offer protection against prostate cancer, Alzheimer's, and may slow cartilage loss in arthritis.

The new study, published in the International Journal of Obesity , suggests that the leaves of the pomegranate may also offer significant health benefits, particularly for weight management supplements market.

Euromonitor International estimates the market to be worth US$0.93bn (€0.73) in Europe in 2005 and $3.93bn in the US.

Du and co-workers looked the effects of pomegranate leaf extract (PLE) in mice eating a high-fat diet that induce obesity and hyperlipidemia (high fat levels in the blood).

In the first of the experiments, the researchers fed mice a high-fat diet to induce obesity, and when body weight was 20 per cent higher than the normal diet control group the high-fat diet was supplemented with PLE (400 or 800 mg/kg/day) for five weeks.

Supplementation with PLE was found to significantly decrease body weight and energy intake after five weeks.

Blood levels of total cholesterol, triglyceride and the ratio of total cholesterol to HDL-cholesterol, reported to be the most specific lipid risk factor for CVD, were also improved after PLE supplementation.

In the second experiment to measure fat absorption, the researchers fed both normal and obese mice a simultaneous dose of 0.5 ml lipid emulsion and PLE (800 mg/kg) and blood levels were measured every hour for six hours after feeding.

In this instance, Du and co-workers report that intestinal fat absorption was inhibited by the leaf extract, while no rise in blood triglyceride levels was observed.

"PLE showed a significant difference in decreasing the appetite of obese mice fed a high-fat diet, but showed no effect in mice fed a normal diet," wrote the researchers.

The mechanism behind the effects, they added, appears to be due to inhibition of pancreatic lipase activity, an enzyme secreted in the pancreas that breaks down fat prior to absorption in the intestine.

There was also a suggestion of appetite suppression, they added.

"PLE can inhibit the development of obesity and hyperlipidemia in high-fat diet induced obese mice," concluded the researchers.

Over 300m adults are obese worldwide, according to latest statistics from the WHO and the International Obesity Task Force.

About one-quarter of the US adult population is said to be obese, with rates in Western Europe on the rise although not yet at similar levels.

Source: International Journal of Obesity Advance on-line publication, doi: 10.1038/sj.ijo.0803502 "Evidence of anti-obesity effects of the pomegranate leaf extract in high-fat diet induced obese mice" Authors: F Lei, X.N. Zhang, W. Wang, D.M. Xing, W.D. Xie, H. Su and L.J. Du