Effect of a novel Omegacoeur®/Doluperine® nutritional combination on human embryonic kidney cell viability.

Holistica Laboratories (Eguilles, France) developed the nutritional supplements Omegacoeur® and Doluperine® based on two of the most ancient and unique dietary health traditions. Omegacoeur® is formulated to supply key active components of Mediterranean diet (omega 3,6,9 fatty acids, garlic, and basil) and the formulation of Doluperine® was based on the Ayurvedic tradition (curcuma, pepper, ginger extracts). Interestingly, recent studies suggest that an combination of the ingredients supplied by these two supplements could provide additional and previously unanticipated benefit through synergistic actions of some of their key components. However, the effect of such combination on human cell viability has not been investigated. In this present article, a review of the various effects of the individual compounds of the new combination and the reported active doses, and the result of a study of an combination of Omegacoeur® / Dolupérine® on Human Embryonic Kidney (HEK 293) cells. Incremental doses of 4 Omegacoeur® / Dolupérine® combinations prepared so that the molar ratio DHA (Docosahexaenoic acid) in Omegacoeur® / curcumin in Dolupérine® was kept constant, at 2.5 DHA / 1 curcumin, were added to the culture media. After 24h of incubation, cell viability was assessed by the trypan blue exclusion method. The data suggest that the combination of Omegacoeur® with Dolupérine® does not affect HEK 293 cells viability in the range of doses that have demonstrated beneficial effects in earlier studies.

7-ketocholesterol inhibits Na,K-ATPase activity by decreasing expression of its α1-subunit and membrane fluidity in human endothelial cells.

As cholesterol, oxysterols, can insert the cell membrane and thereby modify the functions of membrane-bound proteins. The Na,K-ATPase is very sensitive to its lipid environment, seems to be involved in important endothelial functions as the regulation of nitric oxide (NO) release. The effects of 7-ketocholesterol , an oxysterol present in oxidized LDL, was investigated on Na,K-ATPase in isolated human endothelial cells. Cells were incubated 24h with lecithin-, cholesterol- or 7-ketocholesterol liposomes (6 µg/ml). K+-stimulated paranitrophenyl phosphatase activity, reflecting Na,K-ATPase activity, was evaluated as well as cell viability and lipoperoxidation. The expression of Na,K-ATPase subunits mRNAs and membrane fluidity were also investigated. As Na,K-ATPase and nitric oxide seem to be related, we determined the production of NO and the expression of endothelial NO synthase mRNAs. Na,K-ATPase activity was strongly decreased by 7-ketocholesterol. This decrease, not related to lipoperoxidation, was correlated with a decreased expression of the Na,K-ATPase α1-subunit messengers and with rigidity of plasma membranes. Cholesterol induced similar effects but was less potent than 7-ketocholesterol. Basal NO production and expression of endothelial NO synthase mRNAs were not modified by 7-ketocholesterol. Our new findings demonstrate that 7-ketocholesterol, used at non toxic doses, was very potent to disrupt the transport of ions by Na,K-ATPase and perturb membrane structure. These data demonstrate that 7-ketocholesterol induces endothelial dysfunction without cell death that may contribute to early events in atherosclerosis.

The standardized Ginkgo biloba extract Egb-761 protects vascular endothelium exposed to oxidized low density lipoproteins.

Dietary antioxidants are frequently proposed as protective agents for the vascular endothelium during the onset of atherosclerosis. This protection may occur at two distinct levels. First, they prevent oxidative modification of atherogenic lipoproteins (LDL). Second, they can provide a cellular protection against oxidized LDL-mediated endothelium dysfunction, although this mechanism remains poorly considered in many instances. To gain insight into the mechanism underlying such cellular protection against oxidized LDL, we examined the impact of a popular traditional medicine, an extract from Ginkgo biloba with well-known antioxidant properties, on two endothelial cells properties: cell adhesion and ionic homeostasis. Cellular lipoperoxides levels were also measured as a marker of cellular oxidative stress. Human umbilical-vein endothelial cells were exposed to native (nat-) or oxidized (ox-) LDL, the latter prepared to be compatible with clinically observed levels of oxidation. Although nat-LDL had little effect, ox-LDL increased endothelial adhesive properties (35%, p<0.01) and lipoperoxidation (45%, p<0.01). Na,K-ATPase activity, a key regulator of ionic homeostasis, was significantly decreased after exposure to nat-LDL (30%, p<0.01) and dramatically depressed after exposure to ox-LDL (65%, p<0.001). The standardized preparation of Ginkgo biloba EGb-761 totally protected adhesive properties and endothelial lipoperoxide levels. Moreover, it limited the decrease in Na,K-ATPase activity induced by ox-LDL to levels similar to nat-LDL. This suggests that EGb-761 protects endothelial adhesive properties and helps prevent the disruption of ionic homeostasis. The EGb-761-mediated inhibition of ox-LDL-induced lipoperoxide levels in endothelial cells appears to be an important mechanism by which Ginkgo biloba extract protects endothelial properties.