Improved extraction procedure for carotenoids from human milk.

An improved method for the extraction of the major carotenoids from human milk is described. Carotenoids were extracted from milk first with ethanol and n-hexane. Then, polar xanthophylls were extracted from n-hexane into ethanol/water. The remaining n-hexane was evaporated, the residue combined with the ethanolic milk fraction and the mixture briefly saponified. Carotenoids were extracted from the hydrolysate with n-hexane, combined with the polar xanthophylls from the non-saponified ethanol/water-extract and separated by HPLC. Using this method we were able to significantly improve the recovery of xanthophylls such as lutein and zeaxanthin from human milk. The recovery rate of all carotenoids was > 90%. This method might not only be of value for milk but should be especially useful in the extraction of carotenoids from human tissues such as the adipose tissue.

Apoptosis, autophagy and ER stress in mevalonate cascade inhibition-induced cell death of human atrial fibroblasts.

3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) are cholesterol-lowering drugs that exert other cellular effects and underlie their beneficial health effects, including those associated with myocardial remodeling. We recently demonstrated that statins induces apoptosis and autophagy in human lung mesenchymal cells. Here, we extend our knowledge showing that statins simultaneously induces activation of the apoptosis, autophagy and the unfolded protein response (UPR) in primary human atrial fibroblasts (hATF). Thus we tested the degree to which coordination exists between signaling from mitochondria, endoplasmic reticulum and lysosomes during response to simvastatin exposure. Pharmacologic blockade of the activation of ER-dependent cysteine-dependent aspartate-directed protease (caspase)-4 and lysosomal cathepsin-B and -L significantly decreased simvastatin-induced cell death. Simvastatin altered total abundance and the mitochondrial fraction of proapoptotic and antiapoptotic proteins, while c-Jun N-terminal kinase/stress-activated protein kinase mediated effects on B-cell lymphoma 2 expression. Chemical inhibition of autophagy flux with bafilomycin-A1 augmented simvastatin-induced caspase activation, UPR and cell death. In mouse embryonic fibroblasts that are deficient in autophagy protein 5 and refractory to autophagy induction, caspase-7 and UPR were hyper-induced upon treatment with simvastatin. These data demonstrate that mevalonate cascade inhibition-induced death of hATF manifests from a complex mechanism involving co-regulation of apoptosis, autophagy and UPR. Furthermore, autophagy has a crucial role in determining the extent of ER stress, UPR and permissiveness of hATF to cell death induced by statins.

Stereospecific and circadian-phase-dependent kinetic behavior of d,l-, l-, and d-propranolol in plasma, heart, and brain of light--dark-synchronized rats.

In light--dark-synchronized male rats, the kinetic behavior of d,l-, l-, and d-propranolol after single (1.78 and 8.89 mg/kg) or multiple drug administration (6 X 8.89 mg/kg) was studied in plasma, heart, and brain both in the light period (L) and in the dark period (D). With either dosage regimen the kinetics of racemic propranolol displayed a temporal dependency, elimination half-lives in plasma, heart, and brain being shorter during D than during L. This was observed with the stereoisomers only after single drug application with no circadian phase dependency at steady-state concentrations. On the other hand, the kinetic behavior of l- and d-propranolol exhibited pronounced stereospecificity in that t1/2 Beta, Vdbeta, plasma clearance, and drug accumulation in heart and brain were greater for l-propranolol than for the d-isomer. Stereospecific differences in t1/2 beta and elimination rate were more pronounced during D. In the light of the flow-dependent hepatic extraction of propranolol it is unlikely that daily variations in microsomal liver enzyme activity are responsible for the chronopharmacokinetics of propranolol. It is assumed that daily variations in liver blood flow, which is more effectively reduced by beta-receptor blockade in the period of increased sympathetic tone during D, are mainly responsible for the chronopharmocokinetics of the therapeutically used d,l-propranolol.