Oral beta-hydroxybutyrate alleviates COVID-19 related acute respiratory distress syndrome: A randomized, single-blind, placebo-controlled trial.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a lung complication of COVID-19 that requires intensive care and ventilation. Beta-hydroxybutyrate (BHB) is a ketone body that can modulate metabolism and inflammation in immune cells and lung tissues. We hypothesized that oral BHB could alleviate COVID-19 related ARDS by reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines. METHODS: We randomized 75 patients with mild (as per Berlin criteria) ARDS symptoms to receive oral 25 g twice daily or placebo for five days. The primary outcome was the change in pro-inflammatory cytokines (Interleukin-1ß, Interleukin-6, interleukin-18, tumour necrosis factor-alpha) and anti-inflammatory cytokine (interleukin-10) from baseline to day 5. The secondary outcomes were the change in BHB levels from baseline to day 5, the number of hospitalization days, and the occurrence of adverse events. RESULTS: Treatment with formulated BHB resulted in a significant decrease in pro-inflammatory cytokines; Interleukin-1ß (p = 0.0204), Interleukin-6 (p = 0.0309), interleukin-18 (p = 0.0116), tumour necrosis factor-alpha (p = 0.0489) and increase in interleukin-10 (p = 0.0246) compared treatment with placebo. Importantly, higher BHB levels (p = 0.0001) were observed after supplementation; additionally, patients who underwent this approach were hospitalized for fewer days. No serious adverse events were reported. CONCLUSION: Beta-hydroxybutyrate, an oral adjunct therapy, has shown promising results in ameliorating symptoms of ARDS. This includes reduced inflammation, oxidative stress, and decreased patient fatigue levels. Further study with a large sample size is warranted to assess the potential of BHB therapy's effectiveness in reducing the development of severe illness. CLINICAL TRIAL REGISTRATION: (http://ctri.nic.in/CTRI/2021/03/031790).

Effect of the ketone beta-hydroxybutyrate on markers of inflammation and immune function in adults with type 2 diabetes.

Pre-clinical and cell culture evidence supports the role of the ketone beta-hydroxybutyrate (BHB) as an immunomodulatory molecule that may inhibit inflammatory signalling involved in several chronic diseases such as type 2 diabetes (T2D), but studies in humans are lacking. Therefore, we investigated the anti-inflammatory effect of BHB in humans across three clinical trials. To investigate if BHB suppressed pro-inflammatory cytokine secretion, we treated LPS-stimulated leukocytes from overnight-fasted adults at risk for T2D with BHB (Study 1). Next (Study 2), we investigated if exogenously raising BHB acutely in vivo by ketone monoester supplementation (KME) in adults with T2D would suppress pro-inflammatory plasma cytokines. In Study 3, we investigated the effect of BHB on inflammation via ex vivo treatment of LPS-stimulated leukocytes with BHB and in vivo thrice-daily pre-meal KME for 14 days in adults with T2D. Ex vivo treatment with BHB suppressed LPS-stimulated IL-1ß, TNF-α, and IL-6 secretion and increased IL-1RA and IL-10 (Study 1). Plasma IL-10 increased by 90 min following ingestion of a single dose of KME in T2D, which corresponded to peak blood BHB (Study 2). Finally, 14 days of thrice-daily KME ingestion did not significantly alter plasma cytokines or leukocyte subsets including monocyte and T-cell polarization (Study 3). However, direct treatment of leukocytes with BHB modulated TNF-α, IL-1ß, IFN-γ, and MCP-1 secretion in a time- and glucose-dependent manner (Study 3). Therefore, BHB appears to be anti-inflammatory in T2D, but this effect is transient and is modulated by the presence of disease, glycaemia, and exposure time.

Dapagliflozin Attenuates Heart Failure With Preserved Ejection Fraction Remodeling and Dysfunction by Elevating ß-Hydroxybutyrate-activated Citrate Synthase.

ABSTRACT: Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, accounting for 50% of all heart failure patients, and is associated with significant mortality. Sodium-glucose cotransporter subtype inhibitor (SGLT2i) is recommended in the AHA and ESC guidelines for the treatment of HFpEF, but the mechanism of SGLT2i to prevent and treat cardiac remodeling and dysfunction is currently unknown, hindering the understanding of the pathophysiology of HFpEF and the development of novel therapeutics. HFpEF model was induced by a high-fat diet (60% calories from lard) + N [w] -nitro- l -arginine methyl ester ( l -NAME-0.5 g/L) (2 Hit) in male Sprague Dawley rats to effectively recapture the myriad phenotype of HFpEF. This study's results showed that administration of dapagliflozin (DAPA, SGLT2 inhibitor) significantly limited the 2-Hit-induced cardiomyocyte hypertrophy, apoptosis, inflammation, oxidative stress, and fibrosis. It also improved cardiac diastolic and systolic dysfunction in a late-stage progression of HFpEF. Mechanistically, DAPA influences energy metabolism associated with fatty acid intake and mitochondrial dysfunction in HFpEF by increasing ß-hydroxybutyric acid (ß-OHB) levels, directing the activation of citrate synthase, reducing acetyl coenzyme A (acetyl-CoA) pools, modulating adenosine 5'-triphosphate production, and increasing the expression of mitochondrial oxidative phosphorylation system complexes I-V. In addition, following clinical DAPA therapy, the blood levels of ß-OHB and citrate synthase increased and the levels of acetyl-CoA in the blood of HFpEF patients decreased. SGLT2i plays a beneficial role in the prevention and treatment of cardiac remodeling and dysfunction in HFpEF model by attenuating cardiometabolic dysregulation.

3-Hydroxybutyrate ameliorates sepsis-associated acute lung injury by promoting autophagy through the activation of GPR109α in macrophages.

BACKGROUND: Sepsis is a systemic inflammatory disease caused by multiple pathogens, with the most commonly affected organ being the lung. 3-Hydroxybutyrate plays a protective role in inflammatory diseases through autophagy promotion; however, the exact mechanism remains unexplored. METHOD: Our study used the MIMIC-III database to construct a cohort of ICU sepsis patients and figure out the correlation between the level of ketone bodies and clinical prognosis in septic patients. In vivo and in vitro models of sepsis were used to reveal the role and mechanism of 3-hydroxybutyrate in sepsis-associated acute lung injury (sepsis-associated ALI). RESULT: Herein, we observed a strong correlation between the levels of ketone bodies and clinical prognosis in patients with sepsis identified using the MIMIC- III database. In addition, exogenous 3-hydroxybutyrate supplementation improved the survival rate of CLP-induced sepsis in mice by promoting autophagy. Furthermore, 3-hydroxybutyrate treatment protected against sepsis-induced lung damage. We explored the mechanism underlying these effects. The results indicated that 3-hydroxybutyrate upregulates autophagy levels by promoting the transfer of transcription factor EB (TFEB) to the macrophage nucleus in a G-protein-coupled receptor 109 alpha (GPR109α) dependent manner, upregulating the transcriptional level of ultraviolet radiation resistant associated gene (UVRAG) and increasing the formation of autophagic lysosomes. CONCLUSION: 3-Hydroxybutyrate can serve as a beneficial therapy for sepsis-associated ALI through the upregulation of autophagy. These results may provide a basis for the development of promising therapeutic strategies for sepsis-associated ALI.

GLUT inhibitor WZB117 induces cytotoxicity with increased production of amyloid-beta peptide in SH-SY5Y cells preventable by beta-hydroxybutyrate: implications in Alzheimer's disease.

BACKGROUND: Inhibitors of glucose transporters are being explored as potential anti-cancer drugs. Decreased cerebral glucose utilization with reduced levels of several glucose transporters is also an important pathogenic signature of neurodegeneration of Alzheimer's disease, but its exact role in the pathogenesis of this disease is not established. We explored in an experimental model if inhibitors of glucose transporters could lead to altered amyloid-beta homeostasis, mitochondrial dysfunction, and neuronal death, which are relevant in the pathogenesis of Alzheimer's disease. METHODS: SH-SY5Y cells (human neuroblastoma cell line) were exposed to an inhibitor (WZB117) of several types of glucose transporters. We examined the effects of glucose hypometabolism on SH-SY5Y cells in terms of mitochondrial functions, production of reactive oxygen species, amyloid-beta homeostasis, and neural cell death. The effect of ß-hydroxybutyrate in ameliorating the effects of WZB117 on SH-SY5Y cells was also examined. RESULTS: We observed that exposure of SH-SY5Y cells to WZB117 caused mitochondrial dysfunction, increased production of reactive oxygen species, loss of cell viability, increased expression of BACE 1, and intracellular accumulation of amyloid ß peptide (Aß42). All the effects of WZB117 could be markedly prevented by co-treatment with ß-hydroxybutyrate. Cyclosporine A, a blocker of mitochondrial permeability transition pore (mPTP) activation, could not prevent cell death caused by WZB117. CONCLUSION: Results in this neuroblastoma model have implications for the pathogenesis of Alzheimer's disease and warrant further explorations of WZB117 in primary cultures of neurons and experimental animal models.

RESET-PKD: a pilot trial on short-term ketogenic interventions in autosomal dominant polycystic kidney disease.

BACKGROUND: Ketogenic dietary interventions (KDI) have been shown to be effective in animal models of polycystic kidney disease (PKD), but data from clinical trials are lacking. METHODS: Ten autosomal dominant PKD (ADPKD) patients with rapid disease progression were enrolled at visit V1 and initially maintained a carbohydrate-rich diet. At V2, patients entered one of the two KDI arms: a 3-day water fast (WF) or a 14-day ketogenic diet (KD). At V3, they resumed their normal diet for 3-6 weeks until V4. At each visit, magnetic resonance imaging kidney and liver volumetry was performed. Ketone bodies were evaluated to assess metabolic efficacy and questionnaires were used to determine feasibility. RESULTS: All participants [KD n = 5, WF n = 5; age 39.8 ± 11.6 years; estimated glomerular filtration rate 82 ± 23.5 mL/min/1.73 m2; total kidney volume (TKV) 2224 ± 1156 mL] were classified as Mayo Class 1C-1E. Acetone levels in breath and beta-hydroxybutyrate (BHB) blood levels increased in both study arms (V1 to V2 average acetone: 2.7 ± 1.2 p.p.m., V2 to V3: 22.8 ± 11.9 p.p.m., P = .0006; V1 to V2 average BHB: 0.22 ± 0.08 mmol/L, V2 to V3: 1.88 ± 0.93 mmol/L, P = .0008). Nine of 10 patients reached a ketogenic state and 9/10 evaluated KDIs as feasible. TKV did not change during this trial. However, we found a significant impact on total liver volume (ΔTLV V2 to V3: -7.7%, P = .01), mediated by changes in its non-cystic fraction. CONCLUSIONS: RESET-PKD demonstrates that short-term KDIs potently induce ketogenesis and are feasible for ADPKD patients in daily life. While TLV quickly changed upon the onset of ketogenesis, changes in TKV may require longer-term interventions.

D-beta-hydroxybutyrate protects against microglial activation in lipopolysaccharide-treated mice and BV-2 cells.

Microglial activation is a key event in neuroinflammation, which, in turn, is a central process in neurological disorders. In this study, we investigated the protective effects of D-beta-hydroxybutyrate (BHB) against microglial activation in lipopolysaccharide (LPS)-treated mice and BV-2 cells. The effects of BHB in mice were assessed using behavioral testing, morphological analysis and immunofluorescence labeling for the microglial marker ionizing calcium-binding adaptor molecule 1 (IBA-1) and the inflammatory cytokine interleukin-6 (IL-6) in the hippocampus. Moreover, we examined the levels of the inflammatory IL-6 and tumor necrosis factor-α (TNF-α), as well as those of the neuroprotective brain-derived neurotrophic factor (BDNF) and transforming growth factor-ß (TGF-ß) in the brain. In addition, we examined the effects of BHB on IL-6, TNF-α, BDNF, TGF-ß, reactive oxygen species (ROS) level and cell viability in LPS-stimulated BV-2 cells. BHB treatments attenuated behavioral abnormalities, reduced the number of IBA-1-positive cells and the intensity of IL-6 fluorescence in the hippocampus, with amelioration of microglia morphological changes in the LPS-treated mice. Furthermore, BHB inhibited IL-6 and TNF-α generation, but promoted BDNF and TGF-ß production in the brain of LPS-treated mice. In vitro, BHB inhibited IL-6 and TNF-α generation, increased BDNF and TGF-ß production, reduced ROS level, ameliorated morphological changes and elevated cell viability of LPS-stimulated BV-2 cells. Together, our findings suggest that BHB exerts protective effects against microglial activation in vitro and in vivo, thereby reducing neuroinflammation.

Ketone body ß-hydroxybutyrate ameliorates colitis by promoting M2 macrophage polarization through the STAT6-dependent signaling pathway.

BACKGROUND: Ketone body ß-hydroxybutyrate (BHB) has received more and more attentions, because it possesses a lot of beneficial, life-preserving effects in the fields of clinical science and medicine. However, the role of BHB in intestinal inflammation has not yet been investigated. METHODS: Colonic mucosa of inflammatory bowel disease (IBD) patients and healthy controls were collected for evaluation of BHB level. Besides, the therapeutic effect of exogenous BHB in a murine model of acute dextran sulfate sodium (DSS)-induced colitis were assessed by body weight change, colon length, disease activity index, and histopathological sections. The regulatory effectors of BHB were analyzed by RT-qPCR, immunofluorescence, and microbe analysis in vivo. Moreover, the molecular mechanism of BHB was further verified in bone marrow-derived macrophages (BMDMs). RESULTS: In this study, significantly reduced BHB levels were found in the colonic mucosa from IBD patients and correlated with IBD activity index. In addition, we demonstrated that the administration of exogenous BHB alleviated the severity of acute experimental colitis, which was characterized by less weight loss, disease activity index, colon shortening, and histology scores, as well as decreased crypt loss and epithelium damage. Furthermore, BHB resulted in significantly increased colonic expression of M2 macrophage-associated genes, including IL-4Ra, IL-10, arginase 1 (Arg-1), and chitinase-like protein 3, following DSS exposure, suggesting an increased M2 macrophage skewing in vivo. Moreover, an in vitro experiment revealed that the addition of BHB directly promoted STAT6 phosphorylation and M2 macrophage-specific gene expression in IL-4-stimulated macrophages. Besides, we found that BHB obviously increased M2 macrophage-induced mucosal repair through promoting intestinal epithelial proliferation. However, the enhancement effect of BHB on M2 macrophage-induced mucosal repair and anti-inflammation was completely inhibited by the STAT6 inhibitor AS1517499. CONCLUSIONS: In summary, we show that BHB promotes M2 macrophage polarization through the STAT6-dependent signaling pathway, which contributes to the resolution of intestinal inflammation and the repair of damaged intestinal tissues. Our finding suggests that exogenous BHB supplement may be a useful therapeutic approach for IBD treatment.

Ketone Metabolite ß-Hydroxybutyrate Ameliorates Inflammation After Spinal Cord Injury by Inhibiting the NLRP3 Inflammasome.

Ketogenic diet (KD) has been shown to be beneficial in a range of neurological disorders, with ketone metabolite ß-hydroxybutyrate (ßOHB) reported to block the nucleotide oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in bone marrow-derived macrophages. In this study, we show that pretreatment with KD or in situ ßOHB suppressed macrophages/microglia activation and the overproduction of inflammatory cytokines, while KD downregulated the expression of NLRP3 inflammasome. Moreover, KD promoted macrophages/microglia transformation from the M1 phenotype to the M2a phenotype following spinal cord injury (SCI) in the in vivo study. Rats in the KD group demonstrated improved behavioral and electrophysiological recovery after SCI when compared to those rats in the standard diet group. The in vitro study performed on BV2 cells indicated that ßOHB inhibited an LPS+ATP-induced inflammatory response and decreased NLRP3 protein levels. Our data demonstrated that pretreatment with KD attenuated neuroinflammation following SCI, probably by inhibiting NLRP3 inflammasome and shifting the activation state of macrophages/microglia from the M1 to the M2a phenotype. Therefore, the ketone metabolite ßOHB might provide a potential future therapeutic strategy for SCI.

ß-Hydroxybutyrate enhances the cytotoxic effect of cisplatin via the inhibition of HDAC/survivin axis in human hepatocellular carcinoma cells.

Ketone bodies, including acetoacetate and ß-hydroxybutyrate (ßOHB), are produced from acetyl coenzyme A in the liver and then secreted into the blood. These molecules are a source of energy for peripheral tissues during exercise or fasting. ßOHB has been reported to inhibit histone deacetylases (HDACs) 1, 3, and 4 in human embryonic kidney 293 cells. Thus, ßOHB may regulate epigenetics by modulating HDACs. There have been several reports that the administration of ßOHB or induction of a physiological state of ketosis has an antitumor effect; however, the mechanism remains unclear. The aim of this study was to investigate whether ßOHB enhances cisplatin-induced apoptosis in hepatocellular carcinoma (HCC) cells by modulating activity and/or expression of HDACs. We found that ßOHB significantly enhanced cisplatin-induced apoptosis and cleavage of caspase-3 and -8 in HCC cells. Further, ßOHB significantly decreased the expression of HDCA 3/5/6 and survivin in liver hepatocellular (HepG2) cells. In HDAC3/6 gene silencing, survivin expression was significantly decreased, and cisplatin-induced cleavage of caspase-3 was significantly enhanced compared with control in HepG2 cells. In conclusion, ßOHB enhanced cisplatin-induced apoptosis via HDAC3/6 inhibition/survivin axis in HepG2 cells, which suggests that ßOHB could be a new adjuvant agent for cisplatin chemotherapy.

Up-regulation of FOXO1 and reduced inflammation by ß-hydroxybutyric acid are essential diet restriction benefits against liver injury.

Liver ischemia and reperfusion injury (IRI) is a major challenge in liver surgery. Diet restriction reduces liver damage by increasing stress resistance; however, the underlying molecular mechanisms remain unclear. We investigated the preventive effect of 12-h fasting on mouse liver IRI. Partial warm hepatic IRI model in wild-type male C57BL/6 mice was used. The control ischemia and reperfusion (IR) group of mice was given food and water ad libitum, while the fasting IR group was given water but not food for 12 h before ischemic insult. In 12-h fasting mice, serum liver-derived enzyme level and tissue damages due to IR were strongly suppressed. Serum ß-hydroxybutyric acid (BHB) was significantly raised before ischemia and during reperfusion. Up-regulated BHB induced an increment in the expression of FOXO1 transcription factor by raising the level of acetylated histone. Antioxidative enzyme heme oxigenase 1 (HO-1), a target gene of FOXO1, then increased. Autophagy activity was also enhanced. Serum high-mobility group box 1 was remarkably lowered by the 12-h fasting, and activation of NF-κB and NLRP3 inflammasome was suppressed. Consequently, inflammatory cytokine production and liver injury were reduced. Exogenous BHB administration or histone deacetylase inhibitor administration into the control fed mice ameliorated liver IRI, while FOXO1 inhibitor administration to the 12-h fasting group exacerbated liver IRI. The 12-h fasting exerted beneficial effects on the prevention of liver IRI by increasing BHB, thus up-regulating FOXO1 and HO-1, and by reducing the inflammatory responses and apoptotic cell death via the down-regulation of NF-κB and NLRP3 inflammasome.

ß-hydroxybutyrate attenuates renal ischemia-reperfusion injury through its anti-pyroptotic effects.

Ketone bodies including ß-hydroxybutyrate (ß-OHB) have been shown to protect against ischemic tissue injury when present at low concentrations. We evaluated the impact of ß-OHB on renal ischemia/reperfusion injury (IRI). Mice were treated with a continuous infusion of ß-OHB using an osmotic mini-pump before and after IRI. We also tested the effects of increasing endogenous serum ß-OHB levels by fasting. Renal IRI was attenuated by ß-OHB treatment compared to saline control, with similar results in the fasting condition. ß-OHB treatment reduced the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and increased expression of forkhead transcription factor O3 (FOXO3), an upstream regulator of pyroptosis. Although ß-OHB treatment did not impact markers of apoptosis, it decreased the expression of caspase-1 and proinflammatory cytokines, indicating that ß-OHB blocked pyroptosis. In a human proximal tubular cell line exposed to hypoxia and reoxygenation, ß-OHB reduced cell death in a FOXO3-dependent fashion. Histone acetylation was decreased in kidneys exposed to IRI and in proximal tubular cells exposed to hypoxia and reoxygenation, and this effect was ameliorated by ß-OHB through the inactivation of histone deacetylases. In vitro, ß-OHB treatment restored histone acetylation at the FOXO3 promoter. Consistent with epigenetic molecular effects, the renoprotective effects of ß-OHB were still observed when the continuous infusion was stopped at the time of IRI. Thus, ß-OHB attenuates renal IRI through anti-pyroptotic effects, likely mediated by an epigenetic effect on FOXO3 expression.

Hibernation-based blood loss therapy increases survivability of lethal hemorrhagic shock in rats.

A small-volume (1 ml/kg) resuscitation fluid based on metabolic adaptations in hibernating mammals was optimized using a rat model of hemorrhagic shock. A previous study of this therapy tested only one concentration of three specific components: 4 M D-stereoisomer of beta-hydroxybutyrate (BHB), 43 mM melatonin, and 20% DMSO. In this study, we considered the range of concentrations of BHB and melatonin seen during the physiological extremes of rapid arousal from hypothermic torpor in natural hibernators and applied these to the non-hibernating Sprague-Dawley rat model. These extremes normally result in ischemia and reperfusion injury in non-hibernating mammals. Dose-ranging studies were conducted for BHB and melatonin in rats with 60% blood loss. BHB was administered at either 4, 2, or 0.4 M concentration in conjunction with 4.3 mM melatonin and 10% DMSO. Subsequently, melatonin was administered at either 4.3, 0.43, 0.0043, 0.000043, or 0 mM in conjunction with 4 M BHB and 2% DMSO. 10-day mean survival showed a dose-dependent trend: rats survived longer with higher concentration of infused BHB (4 M BHB, 7.38 ± 1.75 days; 2 M BHB, 5.25 ± 2.22 days; 0.4 M BHB, 2.07 ± 2.05 days). Administering 4 M BHB without melatonin resulted in low mean survival times (4.38 ± 1.42 days). All treatments containing both 4 M BHB and melatonin, regardless of melatonin concentration, resulted in mean survival times of ~7.5 days. We conclude there is a dose-dependent trend in which higher BHB concentration resulted in improved survival over 10 days.

Sirtuin 3 mediates neuroprotection of ketones against ischemic stroke.

Stroke is one of the leading causes of death. Growing evidence indicates that ketone bodies have beneficial effects in treating stroke, but their underlying mechanism remains unclear. Our previous study showed ketone bodies reduced reactive oxygen species by using NADH as an electron donor, thus increasing the NAD(+)/NADH ratio. In this study, we investigated whether mitochondrial NAD(+)-dependent Sirtuin 3 (SIRT3) could mediate the neuroprotective effects of ketone bodies after ischemic stroke. We injected mice with either normal saline or ketones (beta-hydroxybutyrate and acetoacetate) at 30 minutes after ischemia induced by transient middle cerebral artery (MCA) occlusion. We found that ketone treatment enhanced mitochondria function, reduced oxidative stress, and therefore reduced infarct volume. This led to improved neurologic function after ischemia, including the neurologic score and the performance in Rotarod and open field tests. We further showed that ketones' effects were achieved by upregulating NAD(+)-dependent SIRT3 and its downstream substrates forkhead box O3a (FoxO3a) and superoxide dismutase 2 (SOD2) in the penumbra region since knocking down SIRT3 in vitro diminished ketones' beneficial effects. These results provide us a foundation to develop novel therapeutics targeting this SIRT3-FoxO3a-SOD2 pathway.

The effect of poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) (PHBHHx) and human mesenchymal stem cell (hMSC) on axonal regeneration in experimental sciatic nerve damage.

This study is designed to evaluate the treatment effect of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and human mesenchymal stem cells (hMSC) on axonal regeneration in experimental rat sciatic nerve damage, and compare the results of this modality with autologous nerve grafting. In Spraque-Dawley albino rats, 10-mm-long experimental nerve gaps were created. Three groups were constituted, the gap was repaired with autologous nerve graft (autograft group), PHBHHx nerve graft alone (PHBHHx alone group), and PHBHHx nerve graft with hMSCs inside (PHBHHx with hMSC group), respectively. The results were evaluated with functional recovery, electrophysiological evaluation, and histological evaluation either with light microscopy and transmission electron microscopy for axonal regeneration and myelin formation. In functional evaluation, autograft and PHBHHx with hMSC groups showed functional improvement with time, whereas PHBHHx alone group did not. Electrophysiological evaluation showed better results in autograft and PHBHHx with hMSC groups when compared to PHBHHx alone group. There was no statistical difference between autograft and PHBHHx with hMSC groups. Histological evaluation showed regenerated axons in each group. Autograft group was better than the others, and PHBHHx with hMSC group was better than PHBHHx alone group both for axonal regeneration and myelin formation. This study showed that the nerve grafts which were prepared from PHBHHx with oriented nanofiber three-dimensional surfaces aided to nerve regeneration, either used alone or with hMSC. PHBHHx provided better nerve regeneration when used with hMSCs inside than alone, and reached the same statistical treatment effect in functional evaluation and electrophysiological evaluation when compared to autografting.

3-Hydroxybutyrate methyl ester as a potential drug against Alzheimer's disease via mitochondria protection mechanism.

Alzheimer's disease (AD) is induced by many reasons, including decreased cellular utilization of glucose and brain cell mitochondrial damages. Degradation product of microbially synthesized polyhydroxybutyrate (PHB), namely, 3-hydroxybutyrate (3HB), can be an alternative to glucose during sustained hypoglycemia. In this study, the derivative of 3HB, 3-hydroxybutyrate methyl ester (HBME), was used by cells as an alternative to glucose. HBME inhibited cell apoptosis under glucose deprivation, rescued activities of mitochondrial respiratory chain complexes that were impaired in AD patients and decreased the generation of ROS. Meanwhile, HBME stabilized the mitochondrial membrane potential. In vivo studies showed that HBME crossed the blood brain barrier easier compared with charged 3HB, resulting in a better bioavailability. AD mice treated with HBME performed significantly better (p < 0.05) in the Morris water maze compared with other groups, demonstrating that HBME has a positive in vivo pharmaceutical effect to improve the spatial learning and working memory of mice. A reduced amyloid-ß deposition in mouse brains after intragastric administration of HBME was also observed. Combined with the in vitro and in vivo results, HBME was proposed to be a drug candidate against AD, its working mechanism appeared to be mediated by various effects of protecting mitochondrial damages.

D-ß-hydroxybutyrate is protective in mouse models of Huntington's disease.

Abnormalities in mitochondrial function and epigenetic regulation are thought to be instrumental in Huntington's disease (HD), a fatal genetic disorder caused by an expanded polyglutamine track in the protein huntingtin. Given the lack of effective therapies for HD, we sought to assess the neuroprotective properties of the mitochondrial energizing ketone body, D-ß-hydroxybutyrate (DßHB), in the 3-nitropropionic acid (3-NP) toxic and the R6/2 genetic model of HD. In mice treated with 3-NP, a complex II inhibitor, infusion of DßHB attenuates motor deficits, striatal lesions, and microgliosis in this model of toxin induced-striatal neurodegeneration. In transgenic R6/2 mice, infusion of DßHB extends life span, attenuates motor deficits, and prevents striatal histone deacetylation. In PC12 cells with inducible expression of mutant huntingtin protein, we further demonstrate that DßHB prevents histone deacetylation via a mechanism independent of its mitochondrial effects and independent of histone deacetylase inhibition. These pre-clinical findings suggest that by simultaneously targeting the mitochondrial and the epigenetic abnormalities associated with mutant huntingtin, DßHB may be a valuable therapeutic agent for HD.

Beta-hydroxy-beta-methylbutyrate supplementation in critically ill trauma patients.

BACKGROUND: Negative nitrogen balance and skeletal muscle loss are common in critically injured patients and may contribute to morbidity, mortality and resource utilization. Juven, an enteral supplement which is a combination of beta-hydroxy-beta-methylbutyrate (HMB), arginine (ARG), and glutamine (GLN) has been shown to restore muscle in cachetic acquired immunodeficiency syndrome (AIDS) and cancer patients. More recently HMB has been shown to attenuate cancer-induced muscle loss by decreasing muscle proteolysis. The purpose of this study was to analyze whether HMB alone or in combination with ARG and GLN would have a similar effect on critically injured trauma patients. We hypothesized that nitrogen balance would be improved and muscle proteolysis decreased with HMB and HMB/ARG/GLN supplementation. METHODS: There were 100 adult trauma patients with Injury Severity Score (ISS) >18 were enrolled in this prospective, randomized, blinded study. All patients received standard tube feeds and one of three iso-nitrogenous supplements; HMB, HMB/ARG/ GLN, or placebo (PLAC) for 28 days. Urine, serum, and clinical data were collected for 72 patients receiving at least 7 days of supplementation during the first 14 days of treatment. Urinary 3-methylhistidine (3-MH) was used as a proxy for muscle proteolysis. RESULTS: The three groups were similar in age, gender, mechanism, and severity of injury, with the average ISS being 31.9. Utilizing covariant (ISS) repeated measure (days 1-14) mixed model (SAS) analysis, there was a significant treatment effect (p = 0.05) on nitrogen balance (g/d). Change in nitrogen balance from the first 7 days to the last 7 days was -4.3 for the HMB and -5.6 g/d HMB/ARG/GLN groups compared with -8.9 g/d for the PLAC group. 3-MH to creatinine ratios were not different in the PLAC group as compared with the HMB/ARG/GLN and HMB groups (Treatment Effect, p = 0.80). CONCLUSIONS: These data suggest that supplementation with HMB alone may improve nitrogen balance in critically injured adult patients and that this effect is not a result of lowered muscle protein turnover as originally hypothesized.

KTX 0101: a potential metabolic approach to cytoprotection in major surgery and neurological disorders.

KTX 0101 is the sodium salt of the physiological ketone, D-beta-hydroxybutyrate (betaOHB). This neuroprotectant, which has recently successfully completed clinical Phase IA evaluation, is being developed as an intravenous infusion fluid to prevent the cognitive deficits caused by ischemic foci in the brain during cardiopulmonary bypass (CPB) surgery. KTX 0101 maintains cellular viability under conditions of physiological stress by acting as a "superfuel" for efficient ATP production in the brain and peripheral tissues. Unlike glucose, this ketone does not require phosphorylation before entering the TCA cycle, thereby sparing vital ATP stores. Although no reliable models of CPB-induced ischemia exist, KTX 0101 is powerfully cytoprotectant under the more severe ischemic conditions of global and focal cerebral ischemia, cardiac ischemia and lung hemorrhage. Neuroprotection has been demonstrated by reductions in infarct volume, edema, markers of apoptosis and functional impairment. One significant difference between KTX 0101 and other potential neuroprotectants in development is that betaOHB is a component of human metabolic physiology which exploits the body's own neuroprotective mechanisms. KTX 0101 also protects hippocampal organotypic cultures against early and delayed cell death in an in vitro model of status epilepticus, indicating that acute KTX 0101 intervention in this condition could help prevent the development of epileptiform foci, a key mechanism in the etiology of intractable epilepsy. In models of chronic neurodegenerative disorders, KTX 0101 protects neurons against damage caused by dopaminergic neurotoxins and by the fragment of beta-amyloid, Abeta(1-42), implying possible therapeutic applications for ketogenic strategies in treating Parkinson's and Alzheimer's diseases. Major obstacles to the use of KTX 0101 for long term therapy in chronic disorders, e.g., Parkinson's and Alzheimer's diseases, are the sodium loading problem and the need to administer it in relatively large amounts because of its rapid mitochondrial metabolism. These issues are being addressed by designing and synthesizing orally bioavailable multimers of betaOHB with improved pharmacokinetics.

Supplementation with a combination of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine is safe and could improve hematological parameters.

BACKGROUND: Combining the amino acids arginine and glutamine with the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) has been shown to reverse lean tissue loss in cancer and acquired immunodeficiency syndrome (AIDS) patients. Although each of these nutrients has been shown to be safe, the safety of this mixture has not been reported. Three double-blind studies examined the safety of the combination of HMB, arginine and glutamine on blood chemistries, hematology, emotional profile, and adverse events. METHODS: Study 1 was conducted in healthy adult males (n = 34), study 2 was in HIV patients with AIDS-associated weight loss (n = 43), and study 3 was in cancer patients with wasting (n = 32). Volunteers were assigned to either a placebo or a mixture of 3 g HMB, 14 g arginine, and 14 g glutamine per day. RESULTS: Across the 3 studies, HMB, arginine, and glutamine supplementation was not associated with any adverse indicators of health. The only significant changes noted were positive indicators of health status. HMB, arginine, and glutamine supplementation was associated with an improvement in emotional profile (p = .05), a decreased feeling of weakness (p = .03), and increased red blood cells, hemoglobin, hematocrit, lymphocytes, and eosinophils (p < .05) when compared with placebo-supplemented subjects. Blood creatinine levels were not changed. However, blood urea nitrogen increased (p = .01) with HMB, arginine, and glutamine supplementation, which was possibly caused by the additional nitrogen consumed or to the fact that ureagenesis is influenced by arginine and glutamine supplementation. CONCLUSION: These results show that HMB, arginine, and glutamine can be safely used to treat muscle wasting associated with AIDS and cancer.