Caloric Restriction and Formalin-Induced Inflammation: An Experimental Study in Rat Model

Time restricted feeding alters the behavioural and physiological outcomes to repeated mild traumatic brain injury in male and female rats

Mild traumatic brain injury (mTBI) research has had limited success translating treatments from preclinical models to clinical application for concussion. One major factor that has been overlooked is the near 24-hour availability of food, both for experimental nocturnal rodents and patients suffering from mTBI. Here, we characterised the impact of food restriction limited to either the inactive (day) or the active phase (night), on repetitive mTBI (RmTBI) - induced outcomes in male and female rats. We found that active phase fed rats consumed more food, had increased body weight, and reduced brain weights. Behaviourally, active phase feeding increased motor coordination deficits and caused changes to thermal nociceptive processing following RmTBI. Hypothalamic transcriptomic analysis revealed minor changes in response to RmTBI, and genes associated with oxytocin-vasopressin regulation in response to inactive phase, but not active phase feeding. These transcript changes were absent in females, where the overall effect of RmTBI was minor. Prefrontal cortex lipidomics revealed an increase in sphingomyelin synthesis following injury and marked sex differences in response to feeding. Of the lipids that changed and overlapped between the prefrontal cortex and serum, dihydroceramides, sphingomyelins, and hexosylceramides, were higher in the serum but lower in the prefrontal cortex. Together, these results demonstrate that feeding time alters outcomes to RmTBI, independent of the hypothalamic transcriptome, and injury-specific lipids may serve as useful biomarkers in RmTBI diagnosis.

A Systematic Review of Dietary Lifestyle Interventions for Neuropathic Pain

Background/Objectives: Chronic severe neuropathic pain (NP) affects one in 10 individuals over the age of 30 in North America. Standard pharmacological interventions are associated with significant side effects and have limited effectiveness. Diets seeking to improve physiological health, support gut barrier integrity, and decrease systemic inflammation have recently emerged as powerful tools conferring neuroprotective and anti-inflammatory effects, potentially reducing the overall morbidity and mortality of multiple neurological and metabolic diseases. This systematic review aimed to synthesize the literature around NP outcomes following dietary interventions compared to routine standard of care. Methods: Following PRISMA guidelines, an initial search yielded 15,387 records after deduplication. Six interventional trials specifically assessing dietary interventions for neuropathic pain were included and analyzed. The dietary lifestyle interventions included low-fat plant-based, plant-based fasting-mimicking, low-calorie, potassium-reduced, gluten-free, and intermittent high-protein/Mediterranean diets. Results: The included studies described some statistically significant improvements in pain severity on objective quantitative sensory testing, electrophysiology, imaging, and subjective questionnaires. The overall risk of bias was moderate, with only one trial demonstrating a low risk of bias across all assessed domains. No serious adverse events were identified, and dietary interventions were generally well tolerated. Conclusions: The data collected and synthesized in this systematic review indicate that dietary lifestyle interventions may offer a low-risk, low-cost, low-tech option for chronic neuropathic pain management, potentially improving quality of life and reducing overall morbidity. However, given substantial variability across studies and a moderate risk of bias, further research is warranted to substantiate these findings.

Models in vivo and in vitro for the study of acute and chronic inflammatory activity: A comprehensive review

Inflammatory conditions are among the principal causes of morbidity worldwide, and their treatment continues to be a challenge, given the restricted availability of effective and safe drugs. Thus, the identification of new compounds with biological activity that can be used for the treatment of inflammatory disorders is an essential field in medical and health research, in order to improve the health and quality of life of patients suffering from these diseases. Evaluation of the anti-inflammatory activity of drugs requires the implementation of models that accurately depict the biochemical and/or physiological responses that characterize human inflammation; for this reason, several in vitro and in vivo models have been developed, providing a platform for discovering novel or repurposed compounds. For this reason, in the present review we have selected twelve commonly used models for the evaluation of the anti-inflammatory effect, and extensively describes the difference between in vivo and in vitro models of inflammation, highlighting their advantages and limitations. On the other hand, the inflammatory mechanisms involved in them, the methods employed for their establishment, and the different parameters assessed to determine the anti-inflammatory activity of a given compound are extensively discussed. We expect to provide a comprehensive guide for the improved selection of a suitable model for the preclinical evaluation of plausible anti-inflammatory agents.

Caloric restriction improves inflammation in different tissues of the Wistar rats with obesity and 2K1C renovascular hypertension

Renovascular hypertension (RHV) is the cause of high blood pressure due to left renal ischemia, and obesity and hypertension cause an inflammatory response. This work analyzed the inflammatory and tissue repair profile in renal, hepatic, and cardiac tissues in an animal model of RVH associated with a high-fat diet and caloric restriction. The expressions of RORγ-t, IL-17, T-bet, and TNF-α decreased and IFN-γ increased in the right kidney. In relation to the left kidney, caloric restriction decreased the expression of IFN-γ. In the liver, caloric restriction decreased RORγ-t, IL-17, and T-bet. Hypertension associated with obesity decreased the expression of IFN-γ, while caloric restriction increased. In the right kidney, hypertension and obesity, associated or not with caloric restriction, increased the area of collagen fibers. In the heart and liver, caloric restriction reduced the area of collagen fibers. Caloric restriction increased vascular endothelial growth factor, reduced levels of growth transformation factor-β1 (TGF-β), and increased collagen I in the left kidney. Hypertension/obesity, submitted or not having caloric restriction, increased TGF-β in liver. The results suggest that caloric restriction has beneficial effects in lowering blood pressure and regulating tissue proinflammatory cytokines. However, there was no change in the structure and composition of tissue repair markers.

Efficacy of a Short-Term Low-Calorie Diet in Overweight and Obese Patients with Chronic Sciatica: A Randomized Controlled Trial

Objectives: Chronic sciatica is a common condition. According to Traditional Persian Medicine and recent studies, calorie reduction is thought to be helpful for this condition. The purpose of this work is to evaluate a short-term low-calorie diet (LCD) for ameliorating chronic sciatica in the context of pain relief and reduced disability for patients. Design: In this randomized controlled trial, 96 candidates for the nonsurgical treatment of chronic sciatica were randomly assigned to two groups to receive a 1-month LCD (intervention) or ordinary diet (control), both in combination with nonsteroidal anti-inflammatory drugs (NSAIDs). Afterward, patients were visited at baseline and on days 15, 30, and 60 after treatment. Pain and disability were evaluated using the short-form McGill pain questionnaire (SFMPQ) and the Roland-Morris disability questionnaire (RMDQ), respectively. Results: Both mean RMDQ scores and SFMPQ scores decreased significantly in the LCD group compared to the control group. SFMPQ descriptor scale scores at baseline and on days 15, 30, and 60 in the LCD group were 7.71 ± 1.69, 6.63 ± 1.61, 5.54 ± 1.87, and 4.96 ± 2.02, respectively, and in the control group were 6.63 ± 1.44, 6.69 ± 1.32, 6.64 ± 1.98, and 6.62 ± 2.53, respectively (p = 0.001). RMDQ scores at baseline and on days 15, 30, and 60 in LCD group were 11.17 ± 3.90, 8.60 ± 1.97, 7.50 ± 2.71, and 6.77 ± 3.06, respectively, and in the control group, 10.00 ± 2.20, 9.98 ± 2.29, 9.94 ± 2.94, and 9.85 ± 3.32, respectively (p < 0.001). Conclusion: A short-term (1-month) LCD is effective in decreasing pain and disability in candidates for nonsurgical treatment of chronic sciatica.

Transcriptome Analysis of the Thymus in Short-Term Calorie-Restricted Mice Using RNA-seq

Calorie restriction (CR), which is a factor that expands lifespan and an important player in immune response, is an effective protective method against cancer development. Thymus, which plays a critical role in the development of the immune system, reacts to nutrition deficiency quickly. RNA-seq-based transcriptome sequencing was performed to thymus tissues of MMTV-TGF-α mice subjected to ad libitum (AL), chronic calorie restriction (CCR), and intermittent calorie restriction (ICR) diets in this study. Three cDNA libraries were sequenced using Illumina HiSeq™ 4000 to produce 100 base pair-end reads. On average, 105 million clean reads were mapped and in total 6091 significantly differentially expressed genes (DEGs) were identified (p < 0.05). These DEGs were clustered into Gene Ontology (GO) categories. The expression pattern revealed by RNA-seq was validated by quantitative real-time PCR (qPCR) analysis of four important genes, which are leptin, ghrelin, Igf1, and adinopectin. RNA-seq data has been deposited in NCBI Gene Expression Omnibus (GEO) database (GSE95371). We report the use of RNA sequencing to find DEGs that are affected by different feeding regimes in the thymus.