Hyperbaric oxygen therapy exerts anti-osteoporotic effects in obese and lean D-galactose-induced aged rats.

Obesity accelerates the aging processes, resulting in an aggravation of aging-induced osteoporosis. We investigated the anti-osteoporotic effect of hyperbaric oxygen therapy (HBOT) in obese- and lean-aged rats through measurement of cellular senescence, hypoxia, inflammation, antioxidants, and bone microarchitecture. Obese and lean male Wistar rats were injected with 150 mg/kg/day of D-galactose for 8 weeks to induce aging. Then, all rats were randomly given either sham or HBOT for 14 days. Metabolic parameters were determined. Expression by bone mRNA for cellular senescence, hypoxia, inflammation, antioxidative capacity, and bone remodeling were examined. Micro-computed tomography and atomic absorption spectroscopy were performed to evaluate bone microarchitecture and bone mineral profiles, respectively. We found that HBOT restored the alterations in the mRNA expression level of p16, p21, HIF-1α, TNF-α, IL-6, RANKL, RANK, NFATc1, DC-STAMP, Osx, ALP, and Col1a1 in the bone in obese-and lean- aging rats. In obese-aging rats, HBOT increased the level of expression of Sirt1 and CuZnSOD mRNA and diminished the expression level of HIF-2α and ctsk mRNA to the same levels as the control group. However, HBOT failed to alter catalase and OCN mRNA expression in obese-aged rats. HBOT partially improved the bone microarchitecture in obese-aged rats, but completely restored it in lean-aged rats. Interestingly, HBOT protected against obesity-induced demineralization in obese-aged rats. In summary, HBOT exerts an anti-osteoporotic effect in lean-aged rats and prevents some, but not all the negative effects of obese-aged conditions on bone health. Therefore, HBOT is considered as a potential therapy for aging-induced osteoporosis, regardless of obese status.

Cyclosorus terminans Extract Ameliorates Insulin Resistance and Non-Alcoholic Fatty Liver Disease (NAFLD) in High-Fat Diet (HFD)-Induced Obese Rats.

Interruptins A and B exhibited anti-diabetic, anti-inflammatory, and anti-oxidative effects. This study aimed to investigate the therapeutic ability of extract enriched by interruptins A and B (EEI) from an edible fern Cyclosorus terminans on insulin resistance and non-alcoholic fatty liver disease (NAFLD) in a high-fat diet (HFD)-induced obese rats and elucidate their possible mechanisms. HFD-induced obese rats were treated with EEI for 2 weeks. Real-time polymerase chain reaction (PCR) was used to examine the molecular basis. We found that EEI supplementation significantly attenuated body and liver weight gain, glucose intolerance, and insulin resistance. Concurrently, EEI increased liver and soleus muscle glycogen storage and serum high-density lipoprotein (HDL) levels. EEI also attenuated NAFLD, as indicated by improving liver function. These effects were associated with enhanced expression of insulin signaling genes (Slc2a2, Slc2a4, Irs1 and Irs2) along with diminished expression of inflammatory genes (Il6 and Tnf). Furthermore, EEI led to the suppression of lipogenesis genes, Srebf1 and Fasn, together with an increase in fatty acid oxidation genes, Ppara and Cpt2, in the liver. These findings suggest that EEI could ameliorate HFD-induced insulin resistance and NAFLD via improving insulin signaling pathways, inflammatory response, lipogenesis, and fatty acid oxidation.

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.

Perilla Seed Oil Alleviates Gut Dysbiosis, Intestinal Inflammation and Metabolic Disturbance in Obese-Insulin-Resistant Rats.

BACKGROUND: High-fat diet (HFD) consumption induced gut dysbiosis, inflammation, obese-insulin resistance. Perilla seed oil (PSO) is a rich source of omega-3 polyunsaturated fatty acids with health promotional effects. However, the effects of PSO on gut microbiota/inflammation and metabolic disturbance in HFD-induced obesity have not been investigated. Therefore, we aimed to compare the effects of different doses of PSO and metformin on gut microbiota/inflammation, and metabolic parameters in HFD-fed rats. METHODS: Thirty-six male Wistar rats were fed either a normal diet or an HFD for 24 weeks. At week 13, HFD-fed rats received either 50, 100, and 500 mg/kg/day of PSO or 300 mg/kg/day metformin for 12 weeks. After 24 weeks, the metabolic parameters, gut microbiota, gut barrier, inflammation, and oxidative stress were determined. RESULTS: HFD-fed rats showed gut dysbiosis, gut barrier disruption with inflammation, increased oxidative stress, metabolic endotoxemia, and insulin resistance. Treatment with PSO and metformin not only effectively attenuated gut dysbiosis, but also improved gut barrier integrity and decreased gut inflammation. PSO also decreased oxidative stress, metabolic endotoxemia, and insulin resistance in HFD-fed rats. Metformin had greater benefits than PSO. CONCLUSION: PSO and metformin had the beneficial effect on attenuating gut inflammation and metabolic disturbance in obese-insulin resistance.

Hyperbaric oxygen therapy effectively alleviates D-galactose-induced-age-related cardiac dysfunction via attenuating mitochondrial dysfunction in pre-diabetic rats.

Currently, the prevalence of obesity in aging populations is fast growing worldwide. Aging induced by D-galactose (D-gal) is proven to cause the worsening of cardiac dysfunction in pre-diabetic rats via deteriorating cardiac mitochondrial function. Hyperbaric oxygen therapy (HBOT) has been shown to attenuate D-gal-induced cognitive deterioration through decreased inflammation and apoptosis. We tested the hypothesis that HBOT alleviates D-gal induced cardiac dysfunction via improving mitochondrial function in pre-diabetic rats. Wistar rats (n=56) were fed normal diet or high-fat diet for 12 weeks. For subsequent 8 weeks, they were subcutaneously injected either vehicle (0.9% normal saline) or D-gal (150mg/kg/day). Rats were randomly subdivided into 7 groups at week 21: sham-treated (normal diet fed rats with vehicle (NDV), high-fat diet fed rats with vehicle (HFV), normal diet fed rats with D-gal (NDDg), high-fat diet fed rats with D-gal (HFDg)) and HBOT-treated (HFV, NDDg, HFDg). Sham rats received ambient pressure of oxygen while HBOT-treated ones received 100% oxygen given once daily for 60 minutes at 2 atmosphere absolute. HBOT reduced metabolic impairments, mitochondrial dysfunction and increased autophagy, resulting in an improvement of cardiac function in aged pre-diabetic rats.

Hyperbaric oxygen therapy restores cognitive function and hippocampal pathologies in both aging and aging-obese rats.

The population of obese-elderly has increased prominently around the world. Both aging and obesity are major factors of neurodegeneration. The present study hypothesizes that HBOT attenuates metabolic disturbance, cognitive decline, hippocampal pathologies in aging and aging-obese model. Sixty Wistar rats were separated into 2 groups to receive normal-diet (ND) or high-fat diet (HFD) for 22 weeks. At week 13, ND rats were divided into two subgroups to receive vehicle (0.9 % NSS, s.c) or d-gal (150 mg/kg/d, s.c) for total 10 weeks. HFD rats were injected only d-gal (150 mg/kg/d, s.c; HFDD) for total 10 weeks. At week 20, rats in each subgroup were given sham-treatment (1ATA, 80 L/min, 80 min/day), or HBOT (2ATA, pure O2, 250 L/min, 80 min/day) for 14 days. Novel object location test, metabolic parameters, and hippocampal pathologies were determined after HBOT. d-gal induced insulin resistance, increased oxidative stress, autophagy impairment, microglial hyperactivation, apoptosis, synaptic dysplasticity which resulted in cognitive impairment. d-gal-treated HFD-fed rats had the highest levels of oxidative stress, apoptosis, dendritic spine loss. HBOT attenuated insulin resistance, cognitive impairment, hippocampal aging and pathologies in both models. These findings suggest that HBOT restored insulin sensitivity, hippocampal functions, cognition in aging and aging-obese models.

Neurotensin receptor 1 agonist provides neuroprotection in pre-diabetic rats.

Exogenous treatment of a neurotensin receptor 1 (NTR1) agonist exerted the neuroprotection in an obese and Alzheimer's model. However, the effects of NTR1 modulation on peripheral/hippocampal impairment and cognitive deficit following sustained HFD consumption are poorly understood. Forty rats received a normal diet (ND) or HFD for 16 weeks. At week 13, the ND group received a vehicle (n = 8). Thirty-two HFD-fed group were randomized into four subgroups (n = 8/subgroup) with a vehicle, 1 mg/kg of NTR1 agonist, 1 mg/kg of NTR antagonist, and combined treatment (NTR1 agonist-NTR antagonist) for 2 weeks, s.c. injection. Then, the cognitive tests and peripheral/hippocampal parameters were determined. Our findings demonstrated that NTR1 activator reversed obesity and attenuated metabolic impairment in pre-diabetic rats. It also alleviated hippocampal pathologies and synaptic dysplasticity, leading to deceleration or prevention of cognitive impairment progression. Therefore, NTR1 activation would be a possible novel therapy to decelerate or prevent progression of neuropathology and cognitive impairment in the pre-diabetes.

The comparative effects of high dose atorvastatin and proprotein convertase subtilisin/kexin type 9 inhibitor on the mitochondria of oxidative muscle fibers in obese-insulin resistant female rats.

The present study aimed to compare the effects of high dose atorvastatin and a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor on the mitochondrial function in oxidative muscle fibers in obese female rats. Female Wistar rats were fed with either a normal diet (ND: n = 12) or a high-fat diet (HFD: n = 36) for a total of 15 weeks. At week 13, ND-fed rats received a vehicle, and HFD-fed rats were divided to three groups to receive either a vehicle, 40 mg/kg/day of atorvastatin, or 4 mg/kg/day of PCSK9 inhibitor (SBC-115076) for 3 weeks. Soleus muscles were investigated to assess mitochondrial ROS, membrane potential, swelling, mitochondrial-related protein expression, and level of malondialdehyde (MDA). The results showed that HFD-fed rats with vehicle developed obese-insulin resistance and dyslipidemia. Both atorvastatin and PCSK9 inhibitor reduced obesity and dyslipidemia, as well as improved insulin sensitivity in HFD-fed rats. However, the efficacy of PCSK9 inhibitor to increase weight loss and reduce dyslipidemia in HFD-fed rats was greater than those of atorvastatin. An increase in MDA level, ratio of p-Drp1ser616/total Drp1 protein, CPT1 protein, mitochondrial ROS, and membrane depolarization in the soleus muscle were observed in HFD-fed rats with vehicle. PCSK9 inhibitor enabled the restoration of all these parameters to normal levels. However, atorvastatin facilitated restoration of some parameters, including MDA level, p-Drp1ser616/total Drp1 ratio, and CPT1 protein expression. These findings suggest that PCSK9 inhibitor is superior to atorvastatin in instigating weight loss, cholesterol reduction, and attenuation of mitochondrial oxidative stress in oxidative muscle fibers of obese female rats.

Reversible acetylcholinesterase inhibitory effect of Tabernaemontana divaricata extract on synaptic transmission in rat CA1 hippocampus.

BACKGROUND & OBJECTIVES: Acetylcholinesterase inhibitors (AChE-Is) are used for the treatment of Alzheimer's disease (AD). These drugs including galanthamine have been shown to modulate synaptic activity in hippocampus and improve memory processes. Although Tabernaemontana divaricata extract (TDE) has been used as traditional medicine for various pharmacological effects, its effect in enhancing cholinergic activity provides additional benefit to its known effects. We investigated whether TDE can modulate the synaptic function in hippocampus and compared its effects to those of galanthamine. METHODS: Hippocampal slices were prepared from male wistar rats, functional effects of TDE were characterized by using pharmacological tools and extracellular recordings of field excitatory postsynaptic potentials (fEPSPs). RESULTS: TDE significantly reduced fEPSPs. The fEPSPs reduction was prevented by atropine, but not pancuronium. These TDE effects were similar to those of galanthamine. INTERPRETATION & CONCLUSIONS: Our findings indicate that TDE can effectively modulate synaptic responses in the hippocampus similar to galanthamine, suggesting that this traditional medicine could be beneficial in ageing with ACh deprivation in the brain.

Ethnobotany & ethnopharmacology of Tabernaemontana divaricata.

Tabernaemontana divaricata a common garden plant in tropical countries has been used as a traditional medicine. However, no recent review articles of T. divaricata, particularly discussing its pharmacological properties, are available. This review presents the ethnobotany and ethnopharmacology of T. divaricata as well as its potential therapeutic benefits especially of the alkaloidal and non-alkaloidal constituents. Included, are the characteristics of 66 alkaloids isolated and identified from T. divaricata. Non-alkaloids including the enzymes, pyrolytic oil, hydrocarbons, terpenoid and phenolic acids are also documented. Chemotaxonomic aspects of each alkaloid as well as information regarding the pharmacology of crude extracts and individual alkaloids from T. divaricata have been assembled and appraised. The beneficial properties of T. divaricata are antioxidant, anti-infection, anti-tumour action, analgesia and the enhancement of cholinergic activity in both peripheral and central nervous systems. The augmentation of cholinergic function may be of therapeutic benefit for many neurodegenerative diseases, particularly myasthenia gravis and Alzheimer's disease.

Tabernaemontana divaricata extract inhibits neuronal acetylcholinesterase activity in rats.

The current pharmacotherapy for Alzheimer's disease (AD) is the use of acetylcholinesterase inhibitors (AChE-Is). A previous in vitro study showed that Tabernaemontana divaricata extract (TDE) can inhibit AChE activity. However, neither the AChE inhibitory effects nor the effect on neuronal activity of TDE has been investigated in vivo. To determine those effects of TDE in animal models, the Ellman's colorimetric method was implemented to investigate the cortical and circulating cholinesterase (ChE) activity, and Fos expression was used to determine the neuronal activity in the cerebral cortex, following acute administration of TDE with various doses (250, 500 and 1000 mg/kg) and at different time points. All doses of TDE 2 h after a single administration significantly inhibited cortical AChE activity and enhanced neuronal activity in the cerebral cortex. The enhancement of Fos expression and AChE inhibitory effects in the cerebral cortex among the three TDE-treated groups was not significantly different. A 2 h interval following all doses of TDE administration had no effect on circulating ChE activity. However, TDE significantly inhibited circulating AChE 10, 30 and 60 min after administration. Our findings suggest that TDE is a reversible AChE-I and could be beneficial as a novel therapeutic agent for AD.