Assessment of in vitro removal of cholesterol oxidation products by Lactobacillus casei ATCC334.

Cholesterol oxidation products (COPs) are a group of compounds formed during processing and storage of foods from animal origin. After ingestion, COPs are absorbed in the intestine and can be distributed to serum and various tissues, potentially promoting a variety of toxic effects. Therefore, inhibition of their intestinal absorption may contribute to reduce the health risks associated with dietary intake of COPs. Some studies have shown that drugs and dietary compounds may inhibit the intestinal absorption of dietary COPs. However, proven cholesterol- and/or food toxins-binding lactic acid bacteria have not been previously evaluated as potential COPs removal agents. The aim of this study was to assess the ability of Lactobacillus casei ATCC334 to remove COPs in aqueous solution. Results showed the ability of both growing and resting cells to remove COPs (ca. 30-60%). All COPs-bacterium interactions were specific and partly reversible, being resting cells the most efficient for COPs removal in a ranking order of 7-KC > 7α-OH/7ß-OH > triol > 5,6ß-EP > 5,6α-EP > 25-OH. Binding to the cell wall and/or cell membrane incorporation appears to be the most likely mechanisms involved on COPs removal by L. casei ATCC 334.

Α4ß2 and α7 nicotinic acetylcholine receptor binding predicts choice preference in two cost benefit decision-making tasks.

Nicotinic receptors have been linked to a wide range of cognitive and behavioral functions, but surprisingly little is known about their involvement in cost benefit decision making. The goal of these experiments was to determine how nicotinic acetylcholine receptor (nAChR) expression is related to two forms of cost benefit decision making. Male Long Evans rats were tested in probability- and delay-discounting tasks, which required discrete trial choices between a small reward and a large reward associated with varying probabilities of omission and varying delays to reward delivery, respectively. Following testing, radioligand binding to α4ß2 and α7 nAChR subtypes in brain regions implicated in cost benefit decision making was examined. Significant linear relationships were observed between choice of the large delayed reward in the delay discounting task and α4ß2 receptor binding in both the dorsal and ventral hippocampus. Additionally, trends were found suggesting that choice of the large costly reward in both discounting tasks was inversely related to α4ß2 receptor binding in the medial prefrontal cortex and nucleus accumbens shell. Similar trends suggested that choice of the large delayed reward in the delay discounting task was inversely related to α4ß2 receptor binding in the orbitofrontal cortex, nucleus accumbens core, and basolateral amygdala, as well as to α7 receptor binding in the basolateral amygdala. These data suggest that nAChRs (particularly α4ß2) play both unique and common roles in decisions that require consideration of different types of reward costs.