HEALTH NEWS

Study Title:

Grape Seed Extract Protects Kidneys

Study Abstract

Obesity is a public health problem that contributes to morbidity and mortality from diabetes, heart disease, stroke, and cancers. The purpose of this investigation was to analyse the link between obesity-induced oxidative stress, renal steatosis, and kidney dysfunction, as well as the protective effect of grape seed and skin extract. Rats were fed a standard diet or a high-fat diet for 6 weeks and were either treated or not treated with grape seed and skin extract. Fat-induced oxidative stress was evaluated in the kidney with a special emphasis on transition metals. High-fat diet induced triglyceride deposition and disturbances in kidney function parameters, which are linked to an oxidative stress status and depletion of copper from the kidney. Grape seed and skin extract abrogated almost all fat-induced kidney disturbances. Grape seed and skin extract exerted potential protection against fat-induced kidney lipotoxicity and should find potential application in other kidney-related diseases.

From press release:

New insight into grape seed extract as a therapeutic and preventative measure to fight obesity-induced kidney damage is presented in a new study. Grape seed and skin extract (GSSE) is known to contain powerful antioxidants. This study, published in the journal Applied Physiology, Nutrition, and Metabolism, is the first to make a link between GSSEs and high-fat-diet-induced renal disease.

The authors examined the effect of GSSE processed from a grape cultivar ('Carignan') of Vitis vinifera from northern Tunisia on rats. Rats were fed a high-fat diet that induced a low-grade reno-lipotoxicity, that is, kidney damage associated with lipids. This was characterized by elevations in plasma urea and protein in the urine. The researchers found increased deposits of triglycerides (TG) (especially saturated fatty acids), increased signs of oxidative stress and depleted copper levels in the kidneys. There was also histological evidence of disturbance in the kidney structure. When the animals received GSSE at 500 mg/kg bw (which corresponds to 35g/day for a 70 kg human adult) along with the high-fat diet there was a partial reversal of the TG deposition as well as the histological damage. The authors suggest polyphenols including resveratrol are likely the components in GSSE responsible for the positive effects. Furthermore the GSSE prevented the oxidative stress and copper depletion.

"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 co-author Kamel Charradi, a researcher with the Laboratory of Bioactive Substance at the Center of Biotechnology of Borj-Cedria (CBBC) in Tunisia. This research group has previously published work showing the benefits of GSSE in combating obesity, heart dysfunction, brain lipotoxicity and kidney cancer.

The article "Grape seed and skin extract alleviates high-fat-diet-induced renal lipotoxicity and prevents copper depletion in rats" is available Open Access in the journal Applied Physiology, Nutrition, and Metabolism.

Study Information

Kamel Charradi, Salem Elkahoui, Ines Karkouch, Ferid Limam, Ghaith Hamdaoui, Fethy Ben Hassine, Michèle Veronique El May, Ahmed El May, Ezzedine Aouani.
Grape seed and skin extract alleviates high-fat diet-induced renal lipotoxicity and prevents copper depletion in rat.
Applied Physiology, Nutrition, and Metabolism
2013 February
Laboratory of Bioactive Substance at the Center of Biotechnology of Borj-Cedria (CBBC) in Tunisia.