Dietary myo-inositol hexaphosphate prevents dystrophic calcifications in soft tissues: a pilot study in Wistar rats

Abstract

Myo-inositol hexaphosphate (Ins P 6) is an abundant component of plant seeds. It is also found in significant levels in blood and mammalian tissues, but they are totally dependent on their dietary intake. In the present paper, we describe studies on the effect of Ins P 6 on a model of dystrophic calcification, which was chemically induced by subcutaneous injection of a 0.1% KMnO 4 solution. Male Wistar rats were randomly divided into four groups for treatment over 31 days. A: animals consuming a purified diet in which Ins P 6 was absent but to which 1% of Ins P 6 (as sodium salt) was added. In this group, the Ins P 6 plasma levels (0.393 ± 0.013 μM) were similar to those observed in rats consuming a standard diet. B: animals consuming only the purified diet in which Ins P 6 was absent. In this case the Ins P 6 plasma levels decreased (0.026 ± 0.006 μM); C: animals consuming the same purified diet as group B but received daily subcutaneous injections of 50 μg kg -1 etidronate during the last 14 days. In this case the Ins P 6 plasma levels were also very low (0.025 ± 0.007 μM); D: animals consuming the same diet as group B but a 6% of carob germ (Ins P 6 rich product) was added. The Ins P 6 plasma levels (0.363 ± 0.035 μM) were also similar to those observed in rats consuming a standard diet. After 21 days plaque formation was induced. Calcification plaques were allowed to proceed for 10 days, after which the plaque material present was excised, dried and weighed. It was found that the presence of myo-inositol hexaphosphate (phytate) in plasma at normal concentrations (0.3-0.4 μM) clearly inhibited the development of dystrophic calcifications in soft tissues. These results demonstrates that myo-inositol hexaphosphate acts as an inhibitor of calcium salt crystallization.