Propriétés antiradicalaires de l'eau de La Bourboule

Antiradical capacities of La Bourboule water

Département de Toxicologie, Hydrologie, Hygiène. Faculté des Sciences Pharmaceutiques et Biologiques. BP 83, F 59006 Lille Cedex

Résumé

Les propriétés antiradicalaires de l'eau thermale de La Bourboule ont été étudiées sur des microsomes isolés de foie de rat et sur des cellules d'hépatome humain (cellules Hep 3B) maintenues en culture.

La formation de malondialdéhyde (MDA), un des principaux indicateurs de la peroxydation lipidique, a été suivie sur les microsomes hépatiques préalablement exposés à l'action d'ions Fe²⁺ générateurs de radicaux superoxyde et hydroxyle.

Les cellules Hep 3B ont été soumises à un stress oxydatif par l'intermédiaire de l'action du couple hypoxanthine/xanthine oxydase générateur de radicaux superoxyde, dans différentes conditions, de manière à apprécier le pouvoir " curatif ", le pouvoir " régénératif " et le pouvoir " préventif " de l'eau minérale. Dans ce cas nous avons mesuré les activités enzymatiques SOD et catalase qui constituent de bons marqueurs du stress oxydatif.

Tous les essais ont été réalisés en parallèle dans des milieux préparés à partir soit d'eau ultrapure, soit d'eau thermale ou d'eau reconstituée au laboratoire contenant les éléments minéraux majeurs de l'eau minérale.

L'évolution dans le temps des paramètres mesurés permet de conclure à une meilleure protection vis-à-vis des radicaux libres en présence d'eau de La Bourboule (par rapport à l'eau reconstituée) : d'une part la production de MDA est inférieure dans le cas de l'eau thermale, d'autre part les activités enzymatiques des cellules cultivées dans l'eau thermale sont plus élevées notamment dans les études de régénération et de prévention.

Ainsi, il semblerait que l'eau de La Bourboule manifeste des propriétés anti-radicalaires spécifiques, plus marquées que celles de l'eau reconstituée.

Abstract

The involvement of free radicals in the ageing process, tissu injury and in several diseases is well known. Antioxidant enzymes such as superoxide dismutase (SOD) and catalase play an important role in defense against free radical-toxicity.

The aim of this work was to study the antiradical capacities of the thermal water of La Bourboule.

For this, the formation of malondialhyde (MDA) an important indicator of lipid peroxidation was studied in hepatic microsomes previously exposed to Fe²⁺ ions (FeSO₄ solution) in presence of ultra pure water or La Bourboule water or a water reconstituted with the major mineral elements of the thermal water. The FeSO₄ solution was used to product superoxide and hydroxyl radicals. MDA determination was performed by HPLC. The MDA production was lower in presence of the thermal water compared to the reconstituted water.

Curative, regenerative and preventive effects were determined in human hepatoma cell line Hep 3B. Oxidative stress was induced by the exposure of cells to the hypoxanthine/xanthine oxidase system as a generator of superoxide radicals. The antiradical capacities were estimated by measuring superoxide dismutase and catalase activities which were decreased by oxidative stress realized in presence of ultra-pure water. On the contrary, in presence of thermal or reconstituted water, these enzymatic activities were not modified. Thus, superoxide radicals were supposed to be neutralized in presence of reconstituted water or La Bourboule water before they could injure cells (curative effect). To study the regenerative effects, the oxidative stress was performed on Hep 3B cells cultured in medium with ultra-pure water. Afterwhat, these cells were seeded in new flasks in presence of thermal or reconstituted or ultra-pure water. They were harvested every second day in order to determine enzymatic activities. With La Bourboule water, an increased in SOD and catalase activities was noticed after eight and five days respectively. Thus, the regenerative capacities of cells were better in the thermal water than in reconstituted water. Preventive capacities were noticed on 23 days-cultured cells in these three media, before the oxidative stress. The SOD activity of cells cultured in reconstituted or in La Bourboule water was the same after oxidative stress as the activity noticed in ultra-pure water without stress. Catalase activity was higher when the cells were cultured in reconstituted or in La Bourboule water after the stress. Preventives capacities of La Bourboule water were the major ones. Thus, antiradical capacities seemed to be stronger in La Bourboule water than in reconstituted water.