Evaluation of the cytotoxicity and genotoxicity of extracts of mussels originating from Moroccan Atlantic coast, in human colonic epithelial cells Caco-2

Determination of heavy metal content and lipid profiles in mussel extracts from two sites on the moroccan atlantic coast and evaluation of their biological activities on MIN6 pancreatic cells

Mussels may concentrate pollutants, with possibly significant side effects on human health. Therefore, mussels (Mytilus galloprovincialis) from two sites of the Moroccan Atlantic coast (Jorf Lasfar [JL], an industrial site, and Oualidia [OL], a vegetable-growing area), were subjected to biochemical analyses to quantify the presence of heavy metals (Cd, Cr, and Pb) and to establish the lipid profile: fatty acid, cholesterol, oxysterol, phytosterol and phospholipid content. In addition, mussel lipid extracts known to accumulate numerous toxic components were tested on murine pancreatic β-cells (MIN6), and their biological activities were measured with various flow cytometric and biochemical methods to determine their impacts on cell death induction, organelle dysfunctions (mitochondria, lysosomes, and peroxisomes), oxidative stress and insulin secretion. The characteristics of JL and OL lipid extracts were compared with those of commercially available mussels from Spain (SP) used for human consumption. OL and JL contained heavy metals, high amounts of phospholipids, and high levels of oxysterols; the [(unsaturated fatty acids)/(saturated fatty acids)] ratio, which can be considered a sign of environmental stress leading to lipid peroxidation, was low. On MIN6 cells, JL and OL lipid extracts were able to trigger cell death. This event was associated with overproduction of H2 O2 , increased catalase activity, a decreased GSH level, lipid peroxidation and stimulation of insulin secretion. These effects were not observed with SP lipid extracts. These data suggest that some components from OL and JL lipid extracts might predispose to pancreatic dysfunctions. Epidemiological studies would be needed to assess the global risk on human health and the metabolic disease incidence in a context of regular seafood consumption from the OL and JL areas.

Permeability of rosmarinic acid in Prunella vulgaris and ursolic acid in Salvia officinalis extracts across Caco-2 cell monolayers

ETHNOPHARMACOLOGICAL RELEVANCE

Rosmarinic acid (RA), a caffeic acid-related compound found in high concentrations in Prunella vulgaris (self-heal), and ursolic acid (UA), a pentacyclic triterpene acid concentrated in Salvia officinalis (sage), have been traditionally used to treat inflammation in the mouth, and may also be beneficial for gastrointestinal health in general.

AIM OF THE STUDY

To investigate the permeabilities of RA and UA as pure compounds and in Prunella vulgaris and Salvia officinalis ethanol extracts across human intestinal epithelial Caco-2 cell monolayers.

MATERIALS AND METHODS

The permeabilities and phase II biotransformation of RA and UA as pure compounds and in herbal extracts were compared using Caco-2 cells with HPLC detection.

RESULTS

The apparent permeability coefficient (P(app)) for RA and RA in Prunella vulgaris extracts was 0.2 ± 0.05 × 10(-6)cm/s, significantly increased to 0.9 ± 0.2 × 10(-6)cm/s after β-glucuronidase/sulfatase treatment. P(app) for UA and UA in Salvia officinalis extract was 2.7 ± 0.3 × 10(-6)cm/s and 2.3 ± 0.5 × 10(-6)cm/s before and after β-glucuronidase/sulfatase treatment, respectively. Neither compound was affected in permeability by the herbal extract matrix.

CONCLUSION

RA and UA in herbal extracts had similar uptake as that found using the pure compounds, which may simplify the prediction of compound efficacy, but the apparent lack of intestinal glucuronidation/sulfation of UA is likely to further enhance the bioavailability of that compound compared with RA.

NG108-15 cell-based and protein phosphatase inhibition assays as alternative semiquantitative tools for the screening of lipophilic toxins in mussels. Okadaic acid detection

We report the application of a cell-based assay (CBA) using NG108-15 a hybridoma cell strain and a protein phosphatase inhibition-based assay (PPIA) as alternative toxicological or functional semiquantitative tools, respectively, for the screening of lipophilic toxins in mussels (Mytilusgalloprovincialis). Acetonic extracts were directly tested by CBA and PPIA but severe matrix effects were observed. As a solution, a simple 17-fraction protocol with solid-phase extraction (SPE) cartridges was optimised and applied as a previous step to the CBA or the PPIA. LC-MS/MS analyses were performed in parallel to determine the lipophilic toxins content in mussel extracts. Evaluation of the SPE protocol by LC-MS/MS showed okadaic acid (OA) recovery above 90% and negligible effects of mussel matrix on the SPE performance. The whole methods provided limits of detection of 47 and 45mug OA equivalents/kg for CBA and PPIA, respectively. The combined strategy permitted the identification of OA toxicity in two fractions, and allowed us to clearly distinguish between negative and positive samples, the latter being either OA-spiked or naturally-contaminated samples at levels equal or above the regulatory limit. The combination of fractioning with CBA or PPIA allows the quantification of the toxic and functional effects of samples above these concentrations.