Sex-specific differences in metabolic outcomes after sleeve gastrectomy and intermittent fasting in obese middle-aged mice

Intermittent fasting alleviates postoperative cognitive dysfunction by reducing neuroinflammation in aged mice

Elderly individuals undergoing surgical procedures are often confronted with the peril of experiencing postoperative cognitive dysfunction (POCD). Prior research has demonstrated the exacerbating effect of sevoflurane anesthesia on neuroinflammation, which can further deteriorate the condition of POCD in elderly patients. Intermittent fasting (IF) restricts food consumption to a specific time window and has been demonstrated to ameliorate cognitive dysfunction induced by neuropathic inflammation. We subjected 18-month-old male mice to 16 hours of fasting and 8 hours of unrestricted eating over a 24-hour period for 0, 1, 2, and 4 weeks, followed by abdominal exploration under sevoflurane anesthesia. In this study, we aim to explore the potential impact of IF on postoperative cognitive function in aged mice undergoing sevoflurane surgery through the preoperative implementation of IF measures. The findings indicate two weeks of IF leads to a significant enhancement of learning and memory capabilities in mice following surgery. The cognitive performance, as determined by the novel object recognition and Morris water maze tests, as well as the synaptic plasticity, as measured by in vivo electrophysiological recordings, has demonstrated marked improvements. Furthermore, the administration of IF markedly enhances the expression of synaptic-associated proteins in hippocampal neurons, concomitant with a decreasing expression of pro-inflammatory factors and a reduced density of microglial cells within the hippocampal brain region. To summarize, the results of this study indicate that IF may mitigate inflammation in the hippocampal area of the brain. Furthermore, IF appears to provide a safeguard against cognitive impairment and synaptic plasticity impairment brought on by sevoflurane anesthesia.

Intermittent fasting reduces mouse body fat while maintaining muscle mass by regulating protein synthesis and autophagy

OBJECTIVES

The aim of this study is to investigate the effect of intermittent fasting (IF) on the regulation of skeletal muscle protein metabolism in response to nutrient supplementation during fasting.

METHODS

Twelve-week-old male C57BL/6J mice were assigned to two groups: ad libitum and IF, with the latter having access to food for only 3 h/d. After 6 wk of experimental periods, an oral glucose tolerance test was performed. One week later, phosphate-buffered saline or a glucose and branched-chain amino acid mixture was administered orally, and blood and tissues were collected 30 min later.

RESULTS

The oral glucose tolerance test results revealed that the IF group had better insulin sensitivity. They also had lower body and fat weights while maintaining the same level of skeletal muscle mass as the ad libitum group. The phosphorylation of ribosomal protein S6 in the skeletal muscle, a marker for the activation of protein translation, was greater in the IF group after glucose and branched-chain amino acid mixture administration. Microtubule-associated protein light chain 3-II-to-light chain 3-I ratio, a marker for autophagosome formation, in skeletal muscle during fasting was significantly lower in the IF group than that in the ad libitum group.

CONCLUSIONS

Our findings suggest that adaptation to IF regulates protein synthesis and breakdown, leading to the maintenance of skeletal muscle mass while reducing body fat.