Local cryotherapy is widely used as a treatment for sports-related skeletal muscle injury. However, its molecular mechanisms are unknown. To clarify these mechanisms, in this study, we applied one to three 15-min cold stimulations at 4 °C to various cell lines (in vitro), the tibialis anterior (TA) muscle (ex vivo), and mouse limbs (in vivo). In the in vitro assay, cAMP response element-binding protein 1 (CREB1) was markedly phosphorylated (as pCREB1) and CREB-binding protein (CBP) was recruited to pCREB-1 in response to two or three cold stimulations. In a reporter assay with the cAMP-responsive element, the signals significantly increased after two to three cold stimulations at 4 °C. In the ex vivo study, CREB-targeting genes were significantly upregulated following two or three cold stimulations. The in vivo experiment disclosed that cold stimulation of a mouse limb for 9 days significantly increased mitochondrial DNA copy number and upregulated genes such as Pgc-1α involved in mitochondrial biogenesis. The foregoing results suggest that local cryotherapy increases CREB transcription and upregulates CREB-targeting genes in a manner dependent on cold stimulation frequency and duration. This information may serve as an impetus for further investigations into local cryotherapy as a treatment for sports-related skeletal muscle trauma.

Background: Depression, a multifaceted mental health condition, necessitates a multidimensional approach to treatment. This study aimed to elucidate the potential efficacy of various mitochondrial interventions, ranging from pharmacological treatments to lifestyle modifications, in alleviating depressive symptoms and enhancing overall mental well-being and assess the diverse range of mitochondrial assessments for managing depression by synthesizing findings from selected studies. Methods: A systematic compilation of studies, employing observational, interventional, and animal-based designs, was undertaken to elucidate the intricate relationship between mitochondrial function and depression as well as depressive signs and symptoms. The PRISMA guidelines were employed for conducting this review and a specific set of selection criterion were formulated by a team of reviewers for selection of relevant papers. Results: The synthesized results from the 21 selected papers highlighted the potential of these interventions to target diverse aspects of depression. Hyperbaric oxygen therapy and psychotherapy demonstrated significant reductions in depression and anxiety scores, with hyperbaric oxygen therapy particularly effective in improving nerve function and daily living activities. Whole-body cryotherapy displayed substantial improvements in depressive symptoms and quality of life. Frequent sauna bathing exhibited a lower risk of depressive symptoms in males. Dietary patterns, including Paleolithic and Mediterranean diets, showcased potential protective effects against depression, anxiety, and stress. The ketogenic diet revealed promise in ameliorating depression and psychosis symptoms alongside positive metabolic changes. Fasting interventions, though challenging, were associated with lower anxiety and depression levels without increased fatigue. Bright white light therapy enhanced remission rates and reduced depression scores in bipolar depression. Probiotic supplementation exhibited potential in reducing depression scores and improving metabolic markers, although further investigation is warranted. Conclusion: The diverse array of interventions explored in this study underlines the multifaceted nature of depression treatment. While these findings offer hope for more personalized and effective approaches, it is imperative to consider the variability in study designs, sample sizes, and methodologies among the selected papers. The mechanisms underlying the observed effects remain partially understood, emphasizing the need for continued mechanistic research. This study sets the stage for future investigations and clinical practices, showcasing the potential of various interventions in mitigating the challenges posed by depression and paving the way for more effective treatment strategies.

This study aims to investigate the impact of body heat loss on the thermal and aerodynamic conditions in a whole-body cryotherapy chamber. The underlying hypothesis is that the heat generated by the human body alters the thermal and aerodynamic environment inside the cabin. A numerical study was conducted to test this hypothesis to analyze the thermodynamic exchanges between the human body and the cabin during a 3-minute whole-body cryotherapy session. The computational fluid dynamics (CFD) approach was used to study the unsteady heat transfer between the human body and the interior of the cryotherapy cabin. A thermal boundary condition, based on a mathematical model developed from experimental data, was applied to simulate skin cooling kinetics over time. The post-processing of the 3D results, including temperature, velocity fields, and thermal flux maps at the body surface, provided insight into the thermo-convective mechanisms involved in a whole-body cryotherapy session. The study found that body heat loss significantly affects the temperature fields inside the cabin, leading to global modifications of the aeraulic and thermal conditions. These findings suggest that cryotherapy protocols may need to be adjusted or the cabin set temperature optimized to enhance the therapeutic benefits.