Facilitated physiological adaptation to prolonged circadian disruption through dietary supplementation with essence of chicken

The interplay between macronutrients and sleep: focus on circadian and homeostatic processes

Sleep disturbances are an emerging risk factor for metabolic diseases, for which the burden is particularly worrying worldwide. The importance of sleep for metabolic health is being increasingly recognized, and not only the amount of sleep plays an important role, but also its quality. In this review, we studied the evidence in the literature on macronutrients and their influence on sleep, focusing on the mechanisms that may lay behind this interaction. In particular, we focused on the effects of macronutrients on circadian and homeostatic processes of sleep in preclinical models, and reviewed the evidence of clinical studies in humans. Given the importance of sleep for health, and the role of circadian biology in healthy sleep, it is important to understand how macronutrients regulate circadian clocks and sleep homeostasis.

Pilose antler polypeptides ameliorates hypoxic-ischemic encephalopathy by activated neurotrophic factors and SDF1/CXCR4 axis in rats

Hypoxic-ischemic encephalopathy (HIE) is a complex condition which is associated with high mortality and morbidity. However, few promising treatments for HIE exist. In the present study, the central objective was to identify the therapeutic effect of pilose antler polypeptides (PAP) on HIE in rats. Sprague-Dawley (SD) rats (14 days old) were used and divided into three groups, including control group, hypoxic-ischemia (HI) group and PAP group. After 21 days of treatment, locomotor activity was improved in PAP-treated rats, brain atrophy was decreased and cerebral edema was mitigated to some extent. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis indicated that PAP administration decreased the expressions of inflammatory cytokines and apoptosis genes in hippocampus compared with HI group. Furthermore, the mRNA expressions of genes related to neurotrophic factors were significantly increased in the hippocampus. In addition, the expressions of oxidative stress markers were all down-regulated after PAP administration. Moreover, PAP up-regulated both the mRNA and protein levels of SDF1 and CXCR4, which may activate the SDF1/CXCR4 axis to moderate brain injury. These results suggest that PAP may be potentially used in the treatment of HIE.

Do night and around-the-clock firefighters' shift schedules induce deviation in tau from 24 hours of systolic and diastolic blood pressure circadian rhythms?

Systolic (S) and diastolic (D) blood pressures (BP) [SBP and DBP] are circadian rhythmic with period (τ) in healthy persons assumed to be maintained at 24.0h. We tested this assumption in a sample of 30 healthy career (mean >12 yrs) 30-to-46 yr-old male Caucasian French firefighters (FFs) categorized into three groups according to work schedule and duties: Group A - 12 FFs working 12h day, 12h night, and occasionally 24h shifts and whose primary duties are firefighting plus paramedical and road rescue services; Group B - 9 FFs working mostly 12h day and 12h night shifts and whose duties are answering incoming emergency calls and coordinating service vehicle dispatch from fire stations with Group A personnel; Group C - 9 day shift (09:00-17:00h) FFs charged with administrative tasks. SBP and DBP, both in winter and in summer studies of the same FFs, were sampled by ambulatory BP monitoring every 1h between 06:00-23:00h and every 2h between 23:01-05:59h, respectively, their approximate off-duty wake and sleep spans, for 7 consecutive days. Activity (wrist actigraphy) was also sampled at 1-min intervals. Prominent τ of each variable was derived by a power spectrum program written for unequal-interval time series data, and between-group differences in incidence of τ≠24h of FFs were assessed by chi square test. Circadian rhythm disruption (τ≠24h) of either the SBP or DBP rhythm occurred almost exclusively in night and 24h shift FFs of Group A and B, but almost never in day shift FFs of Group C, and it was not associated with altered τ from 24.0h of the circadian activity rhythm. In summer, occurrence of τ≠24 for FFs of Group A and B differed from that for FFs of Group C in SBP (p=0.042) and DBP (p=0.015); no such differences were found in winter (p>0.10). Overall, manifestation of prominent τ≠24h of SBP or DBP time series was greater in summer than winter, 27.6% versus 16.7%, when workload of Group B FFs, i.e. number of incoming emergency telephone calls, and of Group A FFs, i.e. number of dispatches for provision of emergency services, was, respectively, two and fourfold greater and number of 12h night shifts worked by Group B FFs and number of 24h shifts worked by Group A FFs was, respectively, 92% and 25% greater. FFs of the three groups exhibited no winter-summer difference in τ≠24h of SBP or SDP; however, τ≠24h of DBP in Group B FFs was more frequent in summer than winter (p=0.046). Sleep/wake cycle disruption, sleep deprivation, emotional and physical stress, artificial light-at-night, and altered nutrient timings are hypothesized causes of τ≠24h for BP rhythms of affected Groups A and B FFs, but with unknown future health effects.

Timing of glucocorticoid administration determines severity of lipid metabolism and behavioral effects in rats

Glucocorticoids (GCs) are a group of steroid hormones secreted by the adrenal glands in circadian cycles, and the dysregulation of GC signaling has been suggested to cause metabolic syndrome. Even though prolonged GC exposure is associated with serious side effects such as metabolic syndrome and central nervous system disorders, the use of GCs in anti-inflammatory and immunosuppressive therapies has been continuously rising. Meanwhile, the exact mechanisms by which GCs can influence the lipid metabolism as well as behavior and how they are affected by time remain unknown. In this study, the effects of two different long-term GC dosing regimens on lipid metabolism and behavior were investigated. Male Wistar rats received daily administrations of the GC dexamethasone sodium phosphate (DEX, 0.5 mg/kg body weight) at either ZT0 (Dex0) or ZT12 (Dex12). After 6 weeks of treatment, DEX-treated rats, especially those treated at ZT0, had higher hepatic lipid accumulation and serum triglyceride levels and less locomotor activity than did control rats. In addition, serum levels of corticosterone, 5-hydroxy tryptamine and norepinephrine were decreased in the Dex0 group but not in the Dex12 group compared to the control group. Furthermore, quantitative real-time polymerase chain reaction analysis indicated that the chronic administration of GCs at ZT0 upregulated genes related to glycolysis and lipid synthesis and downregulated genes related to fatty acid β-oxidation in the liver more remarkably than administration at ZT12. Both DEX-treated groups displayed severely altered expression patterns of the core clock genes Bmal1 and Per2 in the liver and in fat. In addition, the expression of glutamate aspartate transporter, glial fibrillary acidic protein and glutamate transporter-1, astrocyte-related genes important for maintaining nervous system functions, was drastically decreased in the hippocampus of DEX-treated rats, especially when DEX was given at ZT0. In conclusion, our findings confirm that the severity of side effects, indicated by altered lipid metabolism and behavioral activity, depends on the timing of GC administration and is associated with the degree of glucocorticoid receptor dysfunction after dosing at disparate time points.