Effects of mild hyperbaric oxygen on osteoporosis induced by hindlimb unloading in rats

Effects of hyperbaric oxygen therapy on human psychomotor performance: A review

Psychomotor performance is the coordination of a sensory or ideational (cognitive) process and a motor activity. All sensorimotor processes involved in planning and execution of voluntary movements need oxygen supply and seem to be significantly disrupted in states of hypoxia. Hyperbaric oxygen therapy has become a widely used treatment in routine medicine and sport medicine due to its beneficial effects on different aspects of human physiology and performance. This paper presents state-of-the-art data on the effects of hyperbaric oxygen therapy on different aspects of human psychomotor function. The therapy's influence on musculoskeletal properties and motor abilities as well as the effects of hyperbaric oxygenation on cognitive, myocardial and pulmonary functions are presented. In this review the molecular and physiological processes related to human psychomotor performance in response to hyperbaric oxygen are discussed to contribute to this fast-growing field of research in integrative medicine. Please cite this article as: Olex-Zarychta D. Effects of hyperbaric oxygen therapy on human psychomotor performance: A review. J Integr Med. 2023; 21(5): 430-440.

Hypoxia Pathway in Osteoporosis: Laboratory Data for Clinical Prospects

The hypoxia pathway not only regulates the organism to adapt to the special environment, such as short-term hypoxia in the plateau under normal physiological conditions, but also plays an important role in the occurrence and development of various diseases such as cancer, cardiovascular diseases, osteoporosis. Bone, as a special organ of the body, is in a relatively low oxygen environment, in which the expression of hypoxia-inducible factor (HIF)-related molecules maintains the necessary conditions for bone development. Osteoporosis disease with iron overload endangers individuals, families and society, and bone homeostasis disorder is linked to some extent with hypoxia pathway abnormality, so it is urgent to clarify the hypoxia pathway in osteoporosis to guide clinical medication efficiently. Based on this background, using the keywords "hypoxia/HIF, osteoporosis, osteoblasts, osteoclasts, osteocytes, iron/iron metabolism", a matching search was carried out through the Pubmed and Web Of Science databases, then the papers related to this review were screened, summarized and sorted. This review summarizes the relationship and regulation between the hypoxia pathway and osteoporosis (also including osteoblasts, osteoclasts, osteocytes) by arranging the references on the latest research progress, introduces briefly the application of hyperbaric oxygen therapy in osteoporosis symptoms (mechanical stimulation induces skeletal response to hypoxic signal activation), hypoxic-related drugs used in iron accumulation/osteoporosis model study, and also puts forward the prospects of future research.

Hyperbaric oxygen therapy for healthy aging: From mechanisms to therapeutics

Hyperbaric oxygen therapy (HBOT), a technique through which 100% oxygen is provided at a pressure higher than 1 atm absolute (ATA), has become a well-established treatment modality for multiple conditions. The noninvasive nature, favorable safety profile, and common clinical application of HBOT make it a competitive candidate for several new indications, one of them being aging and age-related diseases. In fact, despite the conventional wisdom that excessive oxygen accelerates aging, appropriate HBOT protocols without exceeding the toxicity threshold have shown great promise in therapies against aging. For one thing, an extensive body of basic research has expanded our mechanistic understanding of HBOT. Interestingly, the therapeutic targets of HBOT overlap considerably with those of aging and age-related diseases. For another, pre-clinical and small-scale clinical investigations have provided validated information on the efficacy of HBOT against aging from various aspects. However, a generally applicable protocol for HBOT to be utilized in therapies against aging needs to be defined as a subsequent step. It is high time to look back and summarize the recent advances concerning biological mechanisms and therapeutic implications of HBOT in promoting healthy aging and shed light on prospective directions. Here we provide the first comprehensive overview of HBOT in the field of aging and geriatric research, which allows the scientific community to be aware of the emerging tendency and move beyond conventional wisdom to scientific findings of translational value.

Hyperbaric oxygen therapy improves age induced bone dyshomeostasis in non-obese and obese conditions

AIMS

To investigate the effects of hyperbaric oxygen therapy (HBOT) on metabolic disturbance, aging and bone remodeling in D-galactose-induced aging rats with and without obesity by determining the metabolic parameters, aging and oxidative stress markers, bone turnover markers, bone microarchitecture, and bone biomechanical strength.

MATERIALS AND METHODS

Male Wistar rats were fed either a normal diet (ND; n = 18) or a HFD (n = 12) for 22 weeks. At week 13, vehicle (0.9% NaCl) was injected into ND-fed rats (NDV; n = 6), while 150 mg/kg/day of D-galactose was injected into 12 ND-fed rats (NDD) and 12 HFD-fed rats (HFDD) for 10 weeks. At week 21, rats were treated with either sham (NDVS, NDDS, or HFDDS; n = 6/ group) or HBOT (NDDH, or HFDDH; n = 6/group) for 14 days. Rats were then euthanized. Blood samples, femora, and tibiae were collected.

KEY FINDINGS

Both NDD and HFDD groups developed aging as indicated by increased AGE level, increased inflammation and oxidative stress as shown by raised serum TNF-α and MDA levels, impaired bone remodeling as indicated by an increase in levels of CTX-1, TRACP-5b, and impaired bone structure/strength, when compared with those of the NDVS group. HFD aggravated these indicators of bone dyshomeostasis in D-galactose-treated rats. HBOT restored bone remodeling and bone structure/strength in the NDD group, however HBOT ameliorated bone dyshomeostasis in the HFDD group.

SIGNIFICANCE

HBOT is a potential intervention to decrease the risk of osteoporosis and bone fracture in aging with or without obesity.

Hyperbaric Oxygen Therapy Does Not Have a Negative Impact on Bone Signaling Pathways in Humans

Introduction: Oxygen is emerging as an important factor in the local regulation of bone remodeling. Some preclinical data suggest that hyperoxia may have deleterious effects on bone cells. However, its clinical relevance is unclear. Hence, we studied the effect of hyperbaric oxygen therapy (HBOT) on serum biomarkers reflecting the status of the Wnt and receptor activator of NF-κB ligand (RANKL) pathways, two core pathways for bone homeostasis. Materials and methods: This was a prospective study of 20 patients undergoing HBOT (mean age 58 yrs., range 35–82 yrs.) because of complications of radiotherapy or chronic anal fissure. Patients were subjected to HBOT (100% oxygen; 2.4 atmospheres absolute for 90 min). The average number of HBOT sessions was 20 ± 5 (range 8–31). Serum hypoxia-inducible factor 1-α (HIF1-α), osteoprotegerin (OPG), RANKL, and the Wnt inhibitors sclerostin and dickkopf-1 (DKK1) were measured at baseline and after HBOT by using specific immunoassays. Results: HIF-1α in eight patients with measurable serum levels increased from 0.084 (0.098) ng/mL at baseline to 0.146 (0.130) ng/mL after HBOT (p = 0.028). However, HBOT did not induce any significant changes in the serum levels of OPG, RANKL, sclerostin or DKK1. This was independent of the patients’ diagnosis, either neoplasia or benign. Conclusion: Despite the potential concerns about hyperoxia, we found no evidence that HBOT has any detrimental effect on bone homeostasis.

QiangGuYin Modulates the OPG/RANKL/RANK Pathway by Increasing Secretin Levels during Treatment of Primary Type I Osteoporosis

QiangGuYin (QGY) is a common Traditional Chinese medicine prescription for the treatment of osteoporosis. Previous clinical studies have found that QGY effectively improves bone mineral density (BMD) in postmenopausal women, but its underlying mechanism remains unclear. The osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL)/receptor activator of nuclear factor kappa B (RANK) pathway is a classic pathway involved in osteoporosis. Secretin levels are a serum marker of osteoporosis, but their effect on the OPG/RANKL/RANK pathway has not been reported. Hence, we investigated the relationship between the OPG/RANKL/RANK pathway and secretin and further revealed the mechanism underlying the effect of QGY in the treatment of osteoporosis. Mice were divided into secretin knockdown, secretin overexpression, and corresponding control groups. Micro-computed tomography was used to detect BMD in different groups, and the results show that QGY significantly improved BMD in mice of the secretin knockdown group. To further verify this, the serum levels of OPG, RANKL, RANK, and secretin were measured by enzyme-linked immunosorbent assays, and femur levels of OPG, RANKL, RANK, and secretin were evaluated by real-time quantitative PCR and western blotting. The results show that the expression of OPG was inhibited and that of RANKL and RANK was increased in mice from the secretin knockdown group, whereas the expression of OPG was upregulated and that of RANKL and RANK was downregulated after QGY intervention. Therefore, QGY inhibited bone resorption by promoting the expression of secretin and modulating the OPG/RANKL/RANK pathway. In addition to the effect of QGY, we also revealed the general regulatory effect of secretin on the OPG/RANKL/RANK pathway. We conclude that QGY modulates the OPG/RANKL/RANK pathway by increasing secretin levels during treatment of primary type I osteoporosis. This work provides a theoretical basis for the clinical use of QGY in the treatment of osteoporosis.

Mild hyperbaric oxygen for the early improvement of mood disturbance induced by high-intensity exercise

BACKGROUND

Excessive training stress can result in decreased performance and deep fatigue due to hormonal changes. There are few available data on recovery methods for mood disturbance, especially fatigue, after high-intensity training. This study, therefore, aimed to examine the effects of mild hyperbaric oxygen at 1.3 atmospheres absolute with 31% oxygen on mood disturbance induced by high-intensity exercises.

METHODS

Ten healthy adult men participated in and completed 2 trials: the control (CON) trial and the mild hyperbaric oxygen (MHO) trial. In a randomized crossover design, each subject cycled for 60 min at the physical work capacity at 75% of their maximal heart rate and were subsequently exposed to the CON and MHO conditions for 60 min as the recovery period.

RESULTS

During the 20 to 40 min recovery time points, the average change ratio of heart rates was lower in the MHO trial than in CON (p < 0.05). We observed that the fatigue-inertia, tension-anxiety, and total mood disturbance Profile of Mood States (POMS) scores decreased 60 min post-exercise in the MHO trial, but no differences of these score were observed in the CON trial. There were no differences in oxidative stress, derived-reactive oxygen metabolites, and biological antioxidant potential between both trials. These results suggest that impaired mood states induced by high-intensity exercise can be improved early by MHO without any changes in oxidative stress. This improvement may be associated with decreased heart rate secondary to MHO exposure after the high intensity exercise.

CONCLUSIONS

We conclude that MHO can improve mood disturbances, especially in the fatigue-inertia and tension-anxiety domains, after high-intensity exercise. This study suggest that MHO is potentially an effective recovery method for mood states after high-intensity training.