Mn bioavailability by polarized Caco-2 cells: comparison between Mn gluconate and Mn oxyprolinate

Abstract

BackgroundMicronutrient inadequate intake is responsible of pathological deficiencies and there is a need of assessing the effectiveness of metal supplementation, frequently proposed to rebalance poor diets. Manganese (Mn) is present in many enzymatic intracellular systems crucial for the regulation of cell metabolism, and is contained in commercially available metal supplements.MethodsWe compared the effects of two different commercial Mn forms, gluconate (MnGluc) and oxyprolinate (MnOxP). For this purpose we used the polarized Caco-2 cells cultured on transwell filters, an established in vitro model of intestinal epithelium. Since micronutrient deficiency may accelerate mitochondrial efficiency, the mitochondrial response of these cells, in the presence of MnGluc and MnOxP, by microscopy methods and by ATP luminescence assay was used.ResultsIn the presence of both MnOxP and MnGluc a sustained mitochondrial activity was shown by mitoTraker labeling (indicative of mitochondrial respiration), but ATP intracellular content remained comparable to untreated cells only in the presence of MnOxP. In addition MnOxP transiently up-regulated the antioxidant enzyme Mn superoxide dismutase more efficiently than MnGluc. Both metal treatments preserved NADH and βNADPH diaphorase oxidative activity, avoided mitochondrial dysfunction, as assessed by the absence of a sustained phosphoERK activation, and were able to maintain cell viability.ConclusionsCollectively, our data indicate that MnOxP and MnGluc, and primarily the former, produce a moderate and safe modification of Caco-2 cell metabolism, by activating positive enzymatic mechanisms, thus could contribute to long-term maintenance of cell homeostasis.

Bioavailability Assessment of an Iron Formulation Using Differentiated Human Intestinal Caco-2 Cells

“…Therefore, it is quite important to have new iron formulations that show better safety and efficacy than standard ones. In this context, our results clearly demonstrated the safety and the trans-epithelial transported efficacy of Ferro Supremo, a formulation of liposomal iron enriched with vitamins and micronutrients (FS) compared to FeSO 4 in the presence of vitamin C. To achieve this goal, a differentiated Caco-2 cell has been used as a standard and worldwide preclinical model used for assessing the in vitro bioavailability and safety of different xenobiotics, including food and/or food supplements [ 25 , 26 ] and iron supplements [ 27 ]. In particular, preliminary experiments suggested that FS is not able to severely affect the viability of Caco-2 cells measured by MTT.…”

Mitochondrial Energetics and Ca2+-Activated ATPase in Obstructive Hypertrophic Cardiomyopathy

“…The reaction was stopped by rinsing the sections in PBS. The sections were analyzed using an Eclipse 55i microscope equipped with a DS-L1 camera (Nikon, Tokyo, Japan) [23,24].…”