Consumption of supplements containing grape seed and skin extract (GSSE) may be a valuabletherapeutic and preventative measure to fight obesity-induced kidney damage, according to new research data presented in the journal Applied Physiology, Nutrition, and Metabolism.
The new insights, from researchers in Tunisia, is the first to make a link between grape extract and an effect on kidney problems induced by a high-fat-diet.
In the study, rats were fed a high-fat diet that induced a low-grade kidney damage associated with high-fat diet, however, they found that almost all fat and kidney disturbances were reversed in rats that were given GSSE – which is known to contain powerful antioxidants.
"In our research, obesity-induced leaky kidney and proteinuria are shown to be prevented by GSSE, which suggests the use of GSSE as a preventive nutriceutical for high-risk patients," said study co-author Kamel Charradi, from the Center of Biotechnology of Borj-Cedria (CBBC) in Tunisia.
Charradi and his colleagues examined the effect of GSSE processed from a grape cultivar ('Carignan') of Vitis vinifera from northern Tunisia on rats. The rats were fed a standard diet or a high-fat diet for six weeks before being split to be either supplemented or not supplemented with the grape seed and skin extract at a level of 500 mg/kg body weight – which corresponds to 35grams per day for a 70 kg human adult.
The researchers found that the high-fat-diet increased deposits of triglycerides (TG), raised signs of oxidative stress, and depleted copper levels in the kidneys.
However, when the animals received GSSE along with the high-fat diet there was a partial reversal of the TG deposition as well as repair of the damage caused. Furthermore the GSSE prevented the oxidative stress and copper depletion, the authors said.
Charradi and his team suggested that powerful polyphenols - including resveratrol - are likely the components in GSSE responsible for the positive effects.
Source: Applied Physiology, Nutrition, and Metabolism
Published online ahead of print, doi: 10.1139/apnm-2012-0416
"Grape seed and skin extract alleviates high-fat diet-induced renal lipotoxicity and prevents copper depletion in rat"
Authors: Kamel Charradi, Salem Elkahoui, Ines Karkouch, Ferid Limam, Ghaith Hamdaoui, Fethy Ben Hassine, et al