Assessing the Safety and Therapeutic Efficacy of Cannabidiol Lipid Nanoparticles in Alleviating Metabolic and Memory Impairments and Hippocampal Histopathological Changes in Diabetic Parkinson's Rats.

Diabetic Parkinson's disease (DP) is a progressive neurodegenerative disease with metabolic syndrome that is increasing worldwide. Emerging research suggests that cannabidiol (CBD) is a neuropharmacological compound that acts against this disease, especially CBD in nano-formulation. The safety of cannabidiol lipid nanoparticles (CBD-LNP) was evaluated by assessing in vitro cytotoxicity in neurons and therapeutic outcomes in a DP animal model, including metabolic parameters and histopathology. CBD-LNPs were fabricated by using a microfluidization technique and showed significantly lower cytotoxicity than the natural form of CBD. The DP rats were induced by streptozotocin followed by a 4-week injection of MPTP with a high-fat diet. Rats were treated orally with a vehicle, CBD, CBD-LNP, or levodopa for 4 weeks daily. As a result, vehicle-treated rats exhibited metabolic abnormalities, decreased striatal dopamine levels, and motor and memory deficits. CBD-LNP demonstrated reduced lipid profiles, enhanced insulin secretion, and restored dopamine levels compared to CBD in the natural form. CBD-LNP also had comparable efficacy to levodopa in ameliorating motor deficits and memory impairment in behavior tests. Interestingly, CBD-LNP presented migration of damaged neuronal cells in the hippocampus more than levodopa. These findings suggest that CBD-LNP holds promise as an intervention addressing both metabolic and neurodegenerative aspects of DP, offering a potential therapeutic strategy.

Stress-induced changes in cognitive function and intestinal barrier integrity can be ameliorated by venlafaxine and synbiotic supplementations.

Stress profoundly impacts various aspects of both physical and psychological well-being. Our previous study demonstrated that venlafaxine (Vlx) and synbiotic (Syn) treatment attenuated learned fear-like behavior and recognition memory impairment in immobilized-stressed rats. In this study, we further investigated the physical, behavior, and cellular mechanisms underlying the effects of Syn and/or Vlx treatment on brain and intestinal functions in stressed rats. Adult male Wistar rats, aged 8 weeks old were subjected to 14 days of immobilization stress showed a decrease in body weight gain and food intake as well as an increase in water consumption, urinary corticosterone levels, and adrenal gland weight. Supplementation of Syn and/or Vlx in stressed rats resulted in mitigation of weight loss, restoration of normal food and fluid intake, and normalization of corticosterone levels. Behavioral analysis showed that treatment with Syn and/or Vlx enhanced depressive-like behaviors and improved spatial learning-memory impairment in stressed rats. Hippocampal dentate gyrus showed stress-induced neuronal cell death, which was attenuated by Syn and/or Vlx treatment. Stress-induced ileum inflammation and increased intestinal permeability were both effectively reduced by the supplementation of Syn. In addition, Syn and Vlx partly contributed to affecting the expression of the glial cell-derived neurotrophic factor in the hippocampus and intestines of stressed rats, suggesting particularly protective effects on both the gut barrier and the brain. This study highlights the intricate interplay between stress physiological responses in the brain and gut. Syn intervention alleviate stress-induced neuronal cell death and modulate depression- and memory impairment-like behaviors, and improve stress-induced gut barrier dysfunction which were similar to those of Vlx. These findings enhance our understanding of stress-related health conditions and suggest the synbiotic intervention may be a promising approach to ameliorate deleterious effects of stress on the gut-brain axis.

Oral calcium and vitamin D supplements differentially alter exploratory, anxiety-like behaviors and memory in male rats.

Oral calcium and calcium plus vitamin D supplements are commonly prescribed to several groups of patients, e.g., osteoporosis, fracture, and calcium deficiency. Adequate and steady extracellular calcium levels are essential for neuronal activity, whereas certain forms of calcium supplement (e.g., CaCO3) probably interfere with memory function. However, it was unclear whether a long-term use of ionized calcium (calcium chloride in drinking water ad libitum), vitamin D supplement (oral gavage) or the combination of both affected anxiety and memory, the latter of which was probably dependent on the hippocampal neurogenesis. Here, we aimed to determine the effects of calcium and/or vitamin D supplement on the anxiety- and memory-related behaviors and the expression of doublecortin (DCX), an indirect proxy indicator of hippocampal neurogenesis. Eight-week-old male Wistar rats were divided into 4 groups, i.e., control, calcium chloride-, 400 UI/kg vitamin D3-, and calcium chloride plus vitamin D-treated groups. After 4 weeks of treatment, anxiety-, exploration- and recognition memory-related behaviors were evaluated by elevated pulse-maze (EPM), open field test (OFT), and novel object recognition (NOR), respectively. The hippocampi were investigated for the expression of DCX protein by Western blot analysis. We found that oral calcium supplement increased exploratory behavior as evaluated by OFT and the recognition index in NOR test without any effect on anxiety behavior in EPM. On the other hand, vitamin D supplement was found to reduce anxiety-like behaviors. Significant upregulation of DCX protein expression was observed in the hippocampus of both calcium- and vitamin D-treated rats, suggesting their positive effects on neurogenesis. In conclusion, oral calcium and vitamin D supplements positively affected exploratory, anxiety-like behaviors and/or memory in male rats. Thus, they potentially benefit on mood and memory in osteoporotic patients beyond bone metabolism.

A Shear-Thinning, Self-Healing, Dual-Cross Linked Hydrogel Based on Gelatin/Vanillin/Fe3+ /AGP-AgNPs: Synthesis, Antibacterial, and Wound-Healing Assessment.

A shear-thinning and self-healing hydrogel based on a gelatin biopolymer is synthesized using vanillin and Fe3+ as dual crosslinking agents. Rheological studies indicate the formation of a strong gel found to be injectable and exhibit rapid self-healing (within 10 min). The hydrogels also exhibited a high degree of swelling, suggesting potential as wound dressings since the absorption of large amounts of wound exudate, and optimum moisture levels, lead to accelerated wound healing. Andrographolide, an anti-inflammatory natural product is used to fabricate silver nanoparticles, which are characterized and composited with the fabricated hydrogels to imbue them with anti-microbial activity. The nanoparticle/hydrogel composites exhibit activity against Escherichia coli, Staphylococcus aureus, and Burkholderia pseudomallei, the pathogen that causes melioidosis, a serious but neglected disease affecting southeast Asia and northern Australia. Finally, the nanoparticle/hydrogel composites are shown to enhance wound closure in animal models compared to the hydrogel alone, confirming that these hydrogel composites hold great potential in the biomedical field.

Atomoxetine and escitalopram migrate the derangement of the temporomandibular joint morphologic and histologic changes in rats exposed to stress-induced depression.

PURPOSE: The purpose of this in vivo study was to determine the effects of stress-induced depression and antidepressants on depressive-like behavior, microstructure, and histomorphology of the temporomandibular joint (TMJ) using rats. METHODS: Experimentally induced depression in rats was created before being treated with two antidepressants; escitalopram (selective-serotonin-reuptake inhibitors) and atomoxetine (norepinephrine-reuptake inhibitors). Micro-computed tomography (Micro-CT) was performed to measure the change in bone volume and bone porosity of the condyle. Further histological evaluation of the condylar cartilage was performed. RESULTS: Micro-CT scanning revealed a decrease in bone volume in the depression group. The bone porosity percentage significantly increased in both the escitalopram and atomoxetine groups compared with the control group and the depression group. Histopathological analysis showed increased thickness of cartilage layers in the depression group. In the atomoxetine group, there was a significant increase in the pre-hypertrophic and hypertrophic layer thickness and cell count, but a significant decrease in proteoglycans. CONCLUSION: The present study findings indicated the change in TMJ characteristics, especially on the superficial part of the condylar head in the depression group. Concerning the applicability of the different antidepressants, depression with the treatment of atomoxetine has the most disadvantages due to bone porosity and cartilaginous condyle changes.

Home hazard modification programs for reducing falls in older adults: a systematic review and meta-analysis.

Objective: This study aims to assess the effect of home modification in preventing falls in older adults. Methods: A systematic review and meta-analysis of randomized studies were performed. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered prospectively. Five electronic databases were systematically searched for related articles. The titles and abstracts of the articles found using the key search phrases-home modification and falling-were screened using inclusion and exclusion criteria. The Cochrane risk of bias tool was used to evaluate the studies' methodology. Results: A total of 12 trials were included. A meta-analysis was conducted using 10 studies with n = 1, 960 participants showing a clinically meaningful 7% reduction in falls (risk ratio = 0.93; 0.87-1). Conclusions: Falls can be significantly reduced with the use of home modification interventions that are thorough, well-focused, have an environmental-fit perspective, and have adequate follow-up.

Reliability of the 44-question Home Fall Hazard Assessment Tool and demographic characteristics associated with home hazards among the Thai elderly.

Background: The 44-question Thai Home Fall Hazard Assessment Tool (Thai-HFHAT) was developed to assist healthcare professionals in identifying the risk of falls among community-dwelling older adults from their home environment. However, the reliability of this tool has not been studied. This study aimed to examine the reliability of the 44-question Thai-HFHAT and determine the demographic characteristics associated with home hazards. Methods: A descriptive cross-sectional study design was used to evaluate inter-rater reliability. The participants in this study were 51 older people from various types of Thai houses: a one-story elevated house, a one-story non-elevated house, and a house with two or more floors, 51 caregivers of older patients, and 5 village health volunteers (VHV). A prospective design was used to evaluate test-retest reliability with older people at different times in their homes. All participants answered 44 Thai-HFHAT questions to determine inter-rater and test-retest reliabilities. The reliabilities were analyzed using an intra-class correlation coefficient (ICC). Demographic characteristics including sex, occupation, and education were used to identify the factors affecting home hazards, and linear regression was used to analyze. Results: The ICC of inter-rater reliability of the 44-question Thai-HFHAT was 0.74 (95% CI: 0.57-0.84) and the test-retest reliability was 0.80 (95% CI: 0.64-0.88) for the older adults, 0.80 (95% CI: 0.65-0.89) for the caregivers and 0.70 (95% CI: 0.477-0.83) for the VHV. In demographic variables, personal business career and education level (grades 1-3) had significant relations with the total number of home hazards in the 44-questions Thai-HFHAT. Conclusions: The 44-question Thai-HFHAT is suitable for home hazard assessment among older adults in Thailand. Further studies are needed to investigate changes in the house environment after using the 44-question Thai-HFHAT to determine which changes can reduce fall risk.

Running exercise with and without calcium supplementation from tuna bone reduced bone impairment caused by low calcium intake in young adult rats.

Inadequate calcium intake during childhood and adolescence is detrimental to bone metabolism. Here, we postulated that calcium supplement prepared from tuna bone with tuna head oil should benefit for skeletal development than CaCO3. Forty female 4-week-old rats were divided into calcium-replete diet (0.55% w/w, S1, n = 8) and low-calcium groups (0.15% w/w for 2 weeks; L; n = 32). Then L were subdivided into 4 groups (8/group), i.e., remained on L, L + tuna bone (S2), S2 + tuna head oil + 25(OH)D3 and S2 + 25(OH)D3. Bone specimens were collected at week 9. We found that 2 weeks on low calcium diet led to low bone mineral density (BMD), reduced mineral content, and impaired mechanical properties in young growing rats. Intestinal fractional calcium absorption also increased, presumably resulting from higher plasma 1,25(OH)2D3 (1.712 ± 0.158 in L vs. 1.214 ± 0.105 nM in S1, P < 0.05). Four-week calcium supplementation from tuna bone further increased calcium absorption efficacy, which later returned to the basal level by week 9. Calcium supplementation successfully restored BMD, bone strength and microstructure. However, 25(OH)D3 + tuna head oil + tuna bone showed no additive effect. Voluntary running also effectively prevented bone defects. In conclusion, both tuna bone calcium supplementation and exercise are effective interventions for mitigating calcium-deficient bone loss.

Prevalence of physical activity counseling in primary care: A systematic review and meta-analysis.

Background: This systematic review aimed to summarize and evaluate the prevalence of physical activity (PA) counseling in primary care. Methods: Five databases (CINAHL Complete, Embase, Medline, PsycInfo, and Web of Science) were searched. Primary epidemiological studies on PA counseling in primary care were included. The Joanna Briggs Institute critical appraisal checklist for studies reporting prevalence data was used to assess the quality of studies. The review protocol was registered with PROSPERO (CRD42021284570). Results: After duplicate removal, 4990 articles were screened, and 120 full-text articles were then assessed. Forty studies were included, with quality assessment scores ranging from 5/9 to 9/9. The pooled prevalence of PA counseling based on 35 studies (199830 participants) was 37.9% (95% CI 31.2 to 44.6). The subgroup analyses showed that the prevalence of PA counseling was 33.1% (95% CI: 22.6 to 43.7) in females (10 studies), 32.1% (95% CI: 22.6 to 41.7) in males (10 studies), 65.5% (95% CI: 5.70 to 74.1) in people with diabetes mellitus (6 studies), 41.6% (95% CI: 34.9 to 48.3) in people with hypertension (5 studies), and 56.8% (95% CI: 31.7 to 82.0) in people with overweight or obesity (5 studies). All meta-analyses showed high levels of heterogeneity (I2=93% to 100%). Conclusion: The overall prevalence of PA counseling in primary care was low. The high levels of heterogeneity suggest variability in the perspectives and practices of PA counseling in primary care. PA counseling should be standardized to ensure its optimum effectiveness in primary care.

Construction of the Short-Form Thai-Home Fall Hazard Assessment Tool (Thai-HFHAT-SF) and Testing Its Validity and Reliability in the Elderly.

The Thai-Home Fall Hazard Assessment Tool (Thai-HFHAT) was developed to identify the fall risk among the elderly arising from their home environment. However, it is more time consuming for large items. Therefore, this study developed a short-form of Thai-HFHAT (Thai-HFHAT-SF). In phase I, we developed the Thai-HFHAT-SF by performing a confirmatory factor analysis (CFA) of 450 rural elderly people. In phase II, a total of 105 participants; 50 elderly people, 50 caregivers, and 5 village health volunteers (VHV) were recruited to examine the reliability of the Thai-HFHAT-SF. Intra-class correlation coefficient (ICC) was used to analyze the inter-rater and test-retest reliability. Factor analysis selected 28 out of the 69 original Thai-HFHAT items in 4 components: indoor area, garage, outdoor areas, and risky spots/areas including pets. The factor loading was 0.67, 0.60, 0.32, and 0.31 in each component. The fitness index indicated that this model was fit (χ2/df = 1.38, goodness-of-fit Index (GFI) = 0.988, adjusted goodness-of-fit index (AGFI) = 0.970, standardized root mean square residual (SRMR) = 0.030, and root mean square error of approximation (RMSEA) = 0.029). The inter-rater reliability of the Thai-HFHAT-SF was 0.82 (95% CI: 0.71-0.89). The test-retest reliability was 0.77 (95% CI: 0.60-0.87) for the older person group, 0.85 (95% CI: 0.73-0.91) for the caregiver group, and 0.60 (95% CI: 0.29-0.77) for the VHV group. The new 28-item scale focused on home fall hazards and can be conducted in 10-15 min. Thai-HFHAT-SF is suitable for home hazards assessment among elderly in Thailand.

Enhanced wound healing properties of guar gum/curcumin-stabilized silver nanoparticle hydrogels.

Biocompatible materials that act as scaffolds for regenerative medicine are of enormous interest. Hydrogel-nanoparticle composites have great potential in this regard, however evaluations of their wound healing and safety in vivo in animal studies are scarce. Here we demonstrate that a guar gum/curcumin-stabilized silver nanoparticle hydrogel composite is an injectable material with exceptional wound healing and antibacterial properties. We show that the curcumin-bound silver nanoparticles themselves exhibit low cytotoxicity and enhance proliferation, migration, and collagen production in in vitro studies of human dermal fibroblasts. We then show that the hydrogel-nanoparticle composite promotes wound healing in in vivo studies on rats, accelerating wound closure by > 40% and reducing bacterial counts by 60% compared to commercial antibacterial gels. Histopathology indicates that the hydrogel composite enhances transition from the inflammation to proliferation stage of healing, promoting the formation of fibroblasts and new blood vessels, while target gene expression studies confirm that the accelerated tissue remodeling occurs along the normal pathways. As such these hydrogel composites show great promise as wound dressing materials with high antibacterial capacity.

Synthesis of Benzoazepine Derivatives via Azide Rearrangement and Evaluation of Their Antianxiety Activities.

A new synthetic method for the construction of benzoazepine analogues has been developed employing ortho-arylmethylbenzyl azide derivatives as precursors using an azide rearrangement reaction. In this work, 14 benzoazepine compounds were successfully synthesized in moderate to excellent yields. All synthetic benzoazepines were evaluated for their cytotoxicity against normal human kidney cell line (HEK cell). The results showed that compound 18c had the lowest cytotoxicity (IC50 = 65.68 µM) among tested compounds, which was comparable with the antianxiety drug diazepam (IC50 = 87.90 µM). Based on the cytotoxicity results, five benzoazepine analogues (compounds 18c, 18h, 18j, 18n, and 18p) were selected to determine the antianxiety effect on stressed rats using elevated plus maze (EPM) and open field test (OFT) methods. Interestingly, compound 18c showed better anxiolytic activity than diazepam without a sedative effect by showing superior hyperlocomotor activity. Therefore, this discovery could pave the way for drug development to treat patients with anxiety disorder.

Predictive validity of three home fall hazard assessment tools for older adults in Thailand.

This study aimed to examine the predictive validity of two internationally well-known instruments, the Modified Home Falls and Accidents Screening Tool (Modified HOME FAST) and the Modified Home Falls and Accidents Screening Tool-Self Report (Modified HOME FAST-SR), and the newly developed Thai Home Falls Hazard Assessment Tool (Thai-HFHAT) (69 items) in predicting falls among older Thai adults. It also aimed to examine the predictive validity of the two abbreviated versions (44 and 27 items) of the Thai-HFHAT, which were developed post hoc to accommodate older adults' limited literacy and poor vision and to facilitate the identification of high-impact home fall hazards that are prevalent in the Thailand context. A prospective cohort study was conducted among 450 participants aged 60 years and above who were assessed by the aforementioned tools at baseline, for which data on fall incidence were then collected during the one-year follow-up. The Cox proportional hazard model was applied to estimate hazard ratios (HRs); then, Harrell's C-statistics and receiver operating characteristic (ROC) analyses were conducted to identify the best cutoff point, sensitivity and specificity for each instrument. The results showed that the fall hazard rate was 2.04 times per 1,000 person-days. Taking into account both the predictive validity and applicability, the Thai-HFHAT (44 items) was found to be the most suitable screening tool due to its highest sensitivity and specificity (93% and 72%) at the cutoff score of 18. In conclusion, our study showed that these internationally validated home fall hazard assessment tools were quite applicable for Thailand, but further tailoring the tools into a specific local context yielded even more highly valid tools in predicting fall risk among older Thai adults. Although these findings were well reproducible by inferring from the internal validation results, further external validation in the independent population is necessary.

MT1 and MT2 melatonin receptors are expressed in nonoverlapping neuronal populations.

Melatonin (MLT) exerts its physiological effects principally through two high-affinity membrane receptors MT1 and MT2. Understanding the exact mechanism of MLT action necessitates the use of highly selective agonists/antagonists to stimulate/inhibit a given MLT receptor. The respective distribution of MT1 and MT2 within the CNS and elsewhere is controversial, and here we used a "knock-in" strategy replacing MT1 or MT2 coding sequences with a LacZ reporter. The data show striking differences in the distribution of MT1 and MT2 receptors in the mouse brain: whereas the MT1 subtype was expressed in very few structures (notably including the suprachiasmatic nucleus and pars tuberalis), MT2 subtype receptors were identified within numerous brain regions including the olfactory bulb, forebrain, hippocampus, amygdala and superior colliculus. Co-expression of the two subtypes was observed in very few structures, and even within these areas they were rarely present in the same individual cell. In conclusion, the expression and distribution of MT2 receptors are much more widespread than previously thought, and there is virtually no correspondence between MT1 and MT2 cellular expression. The precise phenotyping of cells/neurons containing MT1 or MT2 receptor subtypes opens new perspectives for the characterization of links between MLT brain targets, MLT actions and specific MLT receptor subtypes.

Agomelatine, venlafaxine, and running exercise effectively prevent anxiety- and depression-like behaviors and memory impairment in restraint stressed rats.

Several severe stressful situations, e.g., natural disaster, infectious disease out break, and mass casualty, are known to cause anxiety, depression and cognitive impairment, and preventive intervention for these stress complications is worth exploring. We have previously reported that the serotonin-norepinephrine-dopamine reuptake inhibitor, venlafaxine, as well as voluntary wheel running are effective in the treatment of anxiety- and depression-like behaviors in stressed rats. But whether they are able to prevent deleterious consequences of restraint stress in rats, such as anxiety/depression-like behaviors and memory impairment that occur afterward, was not known. Herein, male Wistar rats were pre-treated for 4 weeks with anti-anxiety/anti-depressive drugs, agomelatine and venlafaxine, or voluntary wheel running, followed by 4 weeks of restraint-induced stress. During the stress period, rats received neither drug nor exercise intervention. Our results showed that restraint stress induced mixed anxiety- and depression-like behaviors, and memory impairment as determined by elevated plus-maze, elevated T-maze, open field test (OFT), forced swimming test (FST), and Morris water maze (MWM). Both pharmacological pre-treatments and running successfully prevented the anxiety-like behavior, especially learned fear, in stressed rats. MWM test suggested that agomelatine, venlafaxine, and running could prevent stress-induced memory impairment, but only pharmacological treatments led to better novel object recognition behavior and positive outcome in FST. Moreover, western blot analysis demonstrated that venlafaxine and running exercise upregulated brain-derived neurotrophic factor (BDNF) expression in the hippocampus. In conclusion, agomelatine, venlafaxine as well as voluntary wheel running had beneficial effects, i.e., preventing the restraint stress-induced anxiety/depression-like behaviors and memory impairment.

Hepcidin and 1,25(OH)2D3 effectively restore Ca2+ transport in ß-thalassemic mice: reciprocal phenomenon of Fe2+ and Ca2+ absorption.

Previously, ß-thalassemia, an inherited anemic disorder with iron overload caused by loss-of-function mutation of ß-globin gene, has been reported to induce osteopenia and impaired whole body calcium metabolism, but the pathogenesis of aberrant calcium homeostasis remains elusive. Herein, we investigated how ß-thalassemia impaired intestinal calcium absorption and whether it could be restored by administration of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or hepcidin, the latter of which was the liver-derived antagonist of intestinal iron absorption. The results showed that, in hemizygous ß-globin knockout (BKO) mice, the duodenal calcium transport was lower than that in wild-type littermates, and severity was especially pronounced in female mice. Both active and passive duodenal calcium fluxes in BKO mice were found to be less than those in normal mice. This impaired calcium transport could be restored by 7-day 1,25(OH)2D3 treatment. The 1,25(OH)2D3-induced calcium transport was diminished by inhibitors of calcium transporters, e.g., L-type calcium channel, NCX1, and PMCA1b, as well as vesicular transport inhibitors. Interestingly, the duodenal calcium transport exhibited an inverse correlation with transepithelial iron transport, which was markedly enhanced in thalassemic mice. Thus, 3-day subcutaneous hepcidin injection and acute direct hepcidin exposure in the Ussing chamber were capable of restoring the thalassemia-associated impairment of calcium transport; however, the positive effect of hepcidin on calcium transport was completely blocked by proteasome inhibitors MG132 and bortezomib. In conclusion, both 1,25(OH)2D3 and hepcidin could be used to alleviate the ß-thalassemia-associated impairment of calcium absorption. Therefore, our study has shed light on the development of a treatment strategy to rescue calcium dysregulation in ß-thalassemia.

High dietary cholesterol masks type 2 diabetes-induced osteopenia and changes in bone microstructure in rats.

Type 2 diabetes mellitus (T2DM) often occurs concurrently with high blood cholesterol or dyslipidemia. Although T2DM has been hypothesized to impair bone microstructure, several investigations showed that, when compared to age-matched healthy individuals, T2DM patients had normal or relatively high bone mineral density (BMD). Since cholesterol and lipids profoundly affect the function of osteoblasts and osteoclasts, it might be cholesterol that obscured the changes in BMD and bone microstructure in T2DM. The present study, therefore, aimed to determine bone elongation, epiphyseal histology, and bone microstructure in non-obese T2DM Goto-Kakizaki rats treated with normal (GK-ND) and high cholesterol diet. We found that volumetric BMD was lower in GK-ND rats than the age-matched wild-type controls. In histomorphometric study of tibial metaphysis, T2DM evidently suppressed osteoblast function as indicated by decreases in osteoblast surface, mineral apposition rate, and bone formation rate in GK-ND rats. Meanwhile, the osteoclast surface and eroded surface were increased in GK-ND rats, thus suggesting an activation of bone resorption. T2DM also impaired bone elongation, presumably by retaining the chondrogenic precursor cells in the epiphyseal resting zone. Interestingly, several bone changes in GK rats (e.g., increased osteoclast surface) disappeared after high cholesterol treatment as compared to wild-type rats fed high cholesterol diet. In conclusion, high cholesterol diet was capable of masking the T2DM-induced osteopenia and changes in several histomorphometric parameters that indicated bone microstructural defect. Cholesterol thus explained, in part, why a decrease in BMD was not observed in T2DM, and hence delayed diagnosis of the T2DM-associated bone disease.

Beneficial effects of fluoxetine, reboxetine, venlafaxine, and voluntary running exercise in stressed male rats with anxiety- and depression-like behaviors.

Rodents exposed to mild but repetitive stress may develop anxiety- and depression-like behaviors. Whether this stress response could be alleviated by pharmacological treatments or exercise interventions, such as wheel running, was unknown. Herein, we determined anxiety- and depression-like behaviors in restraint stressed rats (2h/day, 5 days/week for 4 weeks) subjected to acute diazepam treatment (30min prior to behavioral test), chronic treatment with fluoxetine, reboxetine or venlafaxine (10mg/kg/day for 4 weeks), and/or 4-week voluntary wheel running. In elevated plus-maze (EPM) and forced swimming tests (FST), stressed rats spent less time in the open arms and had less swimming duration than the control rats, respectively, indicating the presence of anxiety- and depression-like behaviors. Stressed rats also developed learned fear as evaluated by elevated T-maze test (ETM). Although wheel running could reduce anxiety-like behaviors in both EPM and ETM, only diazepam was effective in the EPM, while fluoxetine, reboxetine, and venlafaxine were effective in the ETM. Fluoxetine, reboxetine, and wheel running, but not diazepam and venlafaxine, also reduced depression-like behavior in FST. Combined pharmacological treatment and exercise did not further reduce anxiety-like behavior in stressed rats. However, stressed rats treated with wheel running plus reboxetine or venlafaxine showed an increase in climbing duration in FST. In conclusion, regular exercise (voluntary wheel running) and pharmacological treatments, especially fluoxetine and reboxetine, could alleviate anxiety- and depression-like behaviors in stressed male rats.

Duodenal calcium transporter mRNA expression in stressed male rats treated with diazepam, fluoxetine, reboxetine, or venlafaxine.

Chronic stress has been reported to decrease bone density and intestinal calcium absorption, but its underlying mechanism remains elusive. Since long-term exposure to glucocorticoids, major stress hormones from adrenal gland, is known to downregulate the mRNA expression of intestinal calcium transporter TRPV6, the present study aimed to demonstrate whether decreases in mRNA expressions of duodenal calcium transporter genes were observed in male rats subjected to restraint stress for 4 weeks. The results from quantitative real-time PCR showed that restraint stress significantly downregulated the mRNA expressions of apical calcium channels (TRPV6 and Ca(v)1.3), cytoplasmic calcium-binding protein (calbindin-D(9k)), and basolateral calcium pump (PMCA(1b)), but not the expression of TRPV5 or NCX1. The mRNA expressions of paracellular genes, ZO-1, occludin, and claudin-3, were not altered by restraint stress. Since several antidepressant or anxiolytic drugs effectively alleviate stress-induced depressive and anxiety symptoms, we further hypothesized that these drugs may also enhance calcium transporter gene expression in stressed rats. As expected, 4-week daily administration of 10 mg/kg fluoxetine, 10 mg/kg reboxetine, or 10 mg/kg venlafaxine differentially increased calcium transporter mRNA expression in stressed rats, whereas 2 mg/kg diazepam had no such effect. It could, therefore, be concluded that 4-week restraint stress downregulated some important calcium transporter mRNA expression in the duodenal epithelial cells of male rats, which could be prevented by oral administration of fluoxetine, reboxetine, and venlafaxine. The present findings may be applied to help alleviate the stress-induced bone loss and osteoporosis by restoring intestinal calcium absorption to provide calcium for bone formation.

Anxiolytic-like actions of reboxetine, venlafaxine and endurance swimming in stressed male rats.

Despite being potent anxiolytic agents, benzodiazepines (BDZ) sometimes show reduced therapeutic efficacy in stressed rodents. However, the effectiveness of norepinephrine reuptake inhibitors (NRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) or other anxiolytic interventions, e.g., exercise, remained elusive. Here, we demonstrated that male rats subjected to restraint stress for 4 weeks showed decreases in percent open arm time and open arm entry, as determined by elevated plus-maze test (EPM). Increases in inhibitory avoidance trial 2 and outer zone time were also observed in elevated T-maze (ETM) and open field test (OFT), respectively. To evaluate the anxiolytic-like actions of exercise and anxiolytic drugs, stressed rats were subjected for 4 weeks to swimming or daily gavage with 2mg/kg diazepam (BDZ), or 10mg/kg fluoxetine (selective serotonin reuptake inhibitor), reboxetine (NRI), or venlafaxine (SNRI). In EPM, the open arm activity was higher in the swimming, reboxetine-treated and venlafaxine-treated groups as compared to age-matched controls, while diazepam and fluoxetine were without effect. In ETM, a reduction in avoidance latency was observed only in swimming and venlafaxine-treated groups. However, the combined swimming and pharmacological treatment showed no additive anxiolytic-like effect. It could be concluded that restraint stress induced anxiety-like behaviors, which were not responsive to diazepam or fluoxetine, whereas reboxetine, venlafaxine and swimming showed anxiolytic-like actions in stressed rats.