Upregulation of hepatic autophagy under nutritional ketosis.

Many of the metabolic effects evoked by the ketogenic diet mimic the actions of fasting and the benefits of the ketogenic diet are often attributed to these similarities. Since fasting is a potent autophagy inductor in vivo and in vitro it has been hypothesized that the ketogenic diet may upregulate autophagy. The aim of the present study was to provide a comprehensive evaluation of the influence of the ketogenic diet on the hepatic autophagy. C57BL/6N male mice were fed with two different ketogenic chows composed of fat of either animal or plant origin for 4 weeks. To gain some insight into the time frame for the induction of autophagy on the ketogenic diet, we performed a short-term experiment in which animals were fed with ketogenic diets for only 24 or 48 h. The results showed that autophagy is upregulated in the livers of animals fed with the ketogenic diet. Moreover, the size of the observed effect was likely dependent on the diet composition. Subsequently, the markers of regulatory pathways that may link ketogenic diet action to autophagy were measured, i.e., the activity of mTORC1, activation of AMPK, and the levels of SIRT1, p53, and FOXO3. Overall, observed treatment-specific effects including the upregulation of SIRT1 and downregulation of FOXO3 and p53. Finally, a GC/MS analysis of the fatty acid composition of animals' livers and the chows was performed in order to obtain an idea about the presence of specific compounds that may shape the effects of ketogenic diets on autophagy.

Health risks from consumption of medicinal plant dietary supplements.

The aim of this study was to determine the heavy metal contents of dietary supplements manufactured from medicinal plants and assess the potential daily burden on their consumers. The study consisted of 41 dietary supplements produced from terrestrial plants or microalgae. The analysis of cadmium, lead, and mercury content was performed using analytical methods. The content of Cd and Pb was determined by flame atomic absorption spectrometry (FAAS). The mercury content was determined using atomic absorption spectrometry with the generation of cold mercury vapor (CVAAS). The presence of at least one of the three analyzed heavy metals was found in 79.2% samples of supplements produced from terrestrial plants and in 88.2% supplement samples produced from microalgae. Hazard quotient was used to calculate noncarcinogenic risk for humans by ingestion of dietary supplements containing heavy metals. From among all supplements, 68.3% of samples were contaminated with Cd and Pb (this does not always apply to the same samples) and 29.3% of samples were contaminated with Hg. The health risk assessment of consumers of dietary supplements showed, in an extreme case, that taking this supplement for only one week poses a health risk associated with exposure to Pb. The health risk associated with the intake of dietary supplements primarily depends on the duration of consumption.