In Vitro

Epigallocatechin-3-gallate (EGCG) is the main compound of green tea with well-described antioxidant, anti-inflammatory, and tumor-suppressing properties. However, EGCG at high doses was reported to cause liver injury. In this study, we evaluated the effect of EGCG on primary culture of rat hepatocytes and on rat liver mitochondria in permeabilized hepatocytes. The 24-hour incubation with EGCG in concentrations of 10 μmol/L and higher led to signs of cellular injury and to a decrease in hepatocyte functions. The effect of EGCG on the formation of reactive oxygen species (ROS) was biphasic. While low doses of EGCG decreased ROS production, the highest tested dose induced a significant increase in ROS formation. Furthermore, we observed a decline in mitochondrial membrane potential in cells exposed to EGCG when compared to control cells. In permeabilized hepatocytes, EGCG caused damage of the outer mitochondrial membrane and an uncoupling of oxidative phosphorylation. EGCG in concentrations lower than 10 μmol/L was recognized as safe for hepatocytes in vitro

Effects of Epigallocatechin Gallate on Tert-Butyl Hydroperoxide-Induced Mitochondrial Dysfunction in Rat Liver Mitochondria and Hepatocytes

Epigallocatechin gallate (EGCG) is a green tea antioxidant with adverse effects on rat liver mitochondria and hepatocytes at high doses. Here, we assessed whether low doses of EGCG would protect these systems from damage induced by tert-butyl hydroperoxide (tBHP). Rat liver mitochondria or permeabilized rat hepatocytes were pretreated with EGCG and then exposed to tBHP. Oxygen consumption, mitochondrial membrane potential (MMP), and mitochondrial retention capacity for calcium were measured. First, 50 μM EGCG or 0.25 mM tBHP alone increased State 4 Complex I-driven respiration, thus demonstrating uncoupling effects; tBHP also inhibited State 3 ADP-stimulated respiration. Then, the coexposure to 0.25 mM tBHP and 50 μM EGCG induced a trend of further decline in the respiratory control ratio beyond that observed upon tBHP exposure alone. EGCG had no effect on MMP and no effect, in concentrations up to 50 μM, on mitochondrial calcium retention capacity. tBHP led to a decline in both MMP and mitochondrial retention capacity for calcium; these effects were not changed by pretreatment with EGCG. In addition, EGCG dose-dependently enhanced hydrogen peroxide formation in a cell- and mitochondria-free medium. Conclusion. Moderate nontoxic doses of EGCG were not able to protect rat liver mitochondria and hepatocytes from tBHP-induced mitochondrial dysfunction

Should Carbohydrate Intake Be More Liberal during Oral and Enteral Nutrition in Type 2 Diabetic Patients?

Carbohydrate (CHO) intake in oral and enteral nutrition is regularly reduced in nutritional support of older patients due to the high prevalence of diabetes (usually type 2—T2DM) in this age group. However, CHO shortage can lead to the lack of building blocks necessary for tissue regeneration and other anabolic processes. Moreover, low CHO intake decreases CHO oxidation and can increase insulin resistance. The aim of our current study was to determine the extent to which an increased intake of a rapidly digestible carbohydrate—maltodextrin—affects blood glucose levels monitored continuously for one week in patients with and without T2DM. Twenty-one patients (14 T2DM and seven without diabetes) were studied for two weeks. During the first week, patients with T2DM received standard diabetic nutrition (250 g CHO per day) and patients without diabetes received a standard diet (350 g of CHO per day). During the second week, the daily CHO intake was increased to 400 in T2DM and 500 g in nondiabetic patients by addition of 150 g maltodextrin divided into three equal doses of 50 g and given immediately after the main meal. Plasma glucose level was monitored continually with the help of a subcutaneous sensor during both weeks. The increased CHO intake led to transient postprandial increase of glucose levels in T2DM patients. This rise was more manifest during the first three days of CHO intake, and then the postprandial peak hyperglycemia was blunted. During the night’s fasting period, the glucose levels were not influenced by maltodextrin. Supplementation of additional CHO did not influence the percentual range of high glucose level and decreased a risk of hypoglycaemia. No change in T2DM treatment was indicated. The results confirm our assumption that increased CHO intake as an alternative to CHO restriction in type 2 diabetic patients during oral and enteral nutritional support is safe

The experiences of early career geriatricians throughout Europe during the COVID-19 pandemic

The COVID-19 pandemic has severely affected older adults and brought about unprecedented challenges to geriatricians. We aimed to evaluate the experiences of early career geriatricians (residents or consultants with up to 10 years of experience) throughout Europe using an online survey. We obtained 721 responses. Most of the respondents were females (77.8%) and residents in geriatric medicine (54.6%). The majority (91.4%) were directly involved in the care of patients with COVID-19. The respondents reported moderate levels of anxiety and feelings of being overloaded with work. The anxiety levels were higher in women than in men. Most of the respondents experienced a feeling of a strong restriction on their private lives and a change in their work routine. The residents also reported a moderate disruption in their training and research activities. In conclusion, early career geriatricians experienced a major impact of COVID-19 on their professional and private lives