Antioxidant-rich melon extract may ease stress: Pig study

A daily supplement of an antioxidant-rich melon extract may lower levels of stress proteins in the gut, according to a French study with piglets.

Addition of the commercially-available extract Extramel, produced by France’s Bionov, to the diet of weaned piglets was associated with a significant reduction in levels of stress proteins in the gastrointestinal tract (GIT), including heat-shock proteins, according to findings published in Nutrition.

The melon-extract is a rich source of the antioxidant enzyme superoxide dismutase (SOD). Dubbed 'the enzyme of life' when first discovered in 1968, it is the first antioxidant mobilised by the cell for defence. It is thought to be more powerful than antioxidant vitamins as it activates the body's production of its own antioxidants, including catalase and glutathione peroxidase.

“The present observations may be relevant to humans because beneficial effects of a SOD-rich melon juice concentrate on stress and fatigue have been recently reported in a double-blind, placebo-controlled clinical pilot study [J. Nutr. 2009, Vol. 8, pp. 40],” stated the researchers, led by Jean-Paul Lallès from the French National Institute for Agricultural Research (INRA).

Study details

Dr Lallès and his co-workers selected 36 piglets and after two days of fasting, the animals were then divided into three groups. All animals were fed a standard diet, and two groups had their diets supplemented with 12.5 or 50 International Units per kilogram of food of SOD for three weeks.

The aim of the study was to assess changes, if any, in levels of stress proteins in the intestine of the animals.

“The gastrointestinal tract (GIT) represents a barrier preventing the passage of potentially harmful micro-organisms or toxic substances to the portal circulation; therefore, its protection by stress proteins is of extreme importance with regard to permanent exposure to such aggressors,” explained the researchers.

The results showed that blood levels of SOD increased with increasing doses of the melon.

“[Melon pulp concentrate] supplementation essentially decreased stress proteins in the stomach (all), the mid small intestine (heat-shock protein-27, neuronal nitric oxide synthase) and the colon (heat-shock protein-70, neuronal nitric oxide synthase),” report the researchers.

“Our data provide evidence for the first time, to our knowledge, that diet supplementation with a SOD-rich melon pulp concentrate decreases stress protein expressions along the GIT of piglets,” concluded the researchers.

Source: Nutrition

Published online ahead of print, doi: 10.1016/j.nut.2010.02.005

“A melon pulp concentrate rich in superoxide dismutase reduces stress proteins along the gastrointestinal tract of pigs”

Authors: J-P. Lallès, D. Lacan, J-C. David