Scientists from the University of Granada, Spain, identified the four plant extracts that could help in preventing and fighting obesity through a series of in vitro tests on potential fat fighting compounds.
The most effective extracts in the test-tube were subsequently tested for their anti-obesity potential in rats.
The authors, led by Belén San Román Arenas, from the Biosearch Life Department of Research at Granada, said that whilst the results from their investigation are promising, further studies on animals are required to evaluate and confirm the anti-obesity effects of the extracts. They explained that once the effects are confirmed in animals, the extracts will then be tested on humans.
Román Arenas said the extracts selected in the study come from vegetables commonly consumed by humans, and can be used as nutritional supplements or added to food without problems, “once their effectiveness is tested and verified on humans.”
The researchers said that their research revealed that two of the extracts - which name cannot be disclosed for confidentiality reasons - inhibited the activity of an enzyme that is important in the breakdown of dietary lipids. As such the extracts were shown to reduce lipid absorption.
In addition, the assays uncovered two further extracts, which were found to induce the breakdown of triglycerides accumulated within fat cells – thus reducing their fat content.
The researchers reported that rats fed with a fat-rich diet supplemented with the extracts that demonstrated potential in blocking fat absorption showed a 6-8% increase in the fat excreted in feces – compared to rats fed with a fat-rich diet without any supplementary extract.
They added that obese rats administered the two potentially fat reducing extracts were found to have lower fat cell contents after ten weeks.
“Lipid concentrations in plasma improved as did the parameters associated with the metabolism of glucose -which is related with diabetes and obesity,” said the researchers.
Román Arenas revealed that dietary administration of one of the extracts to obese rats “significantly reduced triglyceride and cholesterol levels in plasma by 67 and 49% respectively” – compared to a control group of obese rats that received no extracts. Glucose and insulin levels in plasma were also significantly improved, they reported.