NADH intraperitoneal injection prevents massive pancreatic beta cell destruction in a streptozotocin-induced diabetes in rats.

Diabetes mellitus is a chronic metabolic disease characterized by persistent hyperglycemia, revealing a decrease in insulin efficiency. The sustained glucotoxic pancreatic microenvironment increases reactive oxygen species generation, resulting in chronic oxidative stress responsible for massive DNA damage. This triggers PARP-1 activation with both NAD+ and ATP depletion, affecting drastically pancreatic beta cells' energy storage and leading to their dysfunction and death. The aim of the present study is to highlight the main histological changes observed in pancreatic islets pre-treated with a unique NADH intraperitoneal injection in a streptozotocin-(STZ)-induced diabetes model. In order to adjust NADH doses, a preliminary study with three different doses, 500 mg/kg, 300 mg/kg, and 150 mg/kg, respectively, was conducted. Subsequently, and on the basis of the results of the aforementioned study, Wistar rats were randomly divided into four groups: non-diabetic control group, diabetics (STZ 45 mg/kg), NADH-treated group (150 mg/kg) 15 min before STZ administration, and NADH-treated group (150 mg/kg) 15 min after STZ administration. The effect of NADH was assessed by blood glucose level, TUNEL staining, histo-morphological analysis, and immunohistochemistry. The optimum protective dose of NADH was 150 mg/kg. NADH effectively decreased hyperglycemia and reduced diabetes induced by STZ. Histologically, NADH pre-treatment revealed a decrease in beta cell death favoring apoptosis over necrosis and therefore preventing inflammation with further beta cell destruction. Our data clearly demonstrate that NADH prior or post-treatment could effectively prevent the deleterious loss of beta cell mass in STZ-induced diabetes in rats and preserve the normal pancreatic islet's function.

Heme oxygenase-1 protects against endotoxin-induced acute lung injury depends on NAD+-mediated mitonuclear communication through PGC1α/PPARγ signaling pathway.

Endotoxin-induced acute lung injury (ALI) is a challenging life-threatening disease for which no specific therapy exists. Mitochondrial dysfunction is corroborated as hallmarks in sepsis which commonly disrupt mitochondria-centered cellular communication networks, especially mitonuclear crosstalk, where the ubiquitous cofactor nicotinamide adenine dinucleotide (NAD+) is essential for mitonuclear communication. Heme oxygenase-1 (HO-1) is critical for maintaining mitochondrial dynamic equilibrium and regulating endoplasmic reticulum (ER) and Golgi stress to alleviating acute lung injury. However, it is unclear whether HO-1 regulates NAD+-mediated mitonuclear communication to exert the endogenous protection during endotoxin-induced ALI. In this study, we observed HO-1 attenuated endotoxin-induced ALI by regulated NAD+ levels and NAD+ affected the mitonuclear communication, including mitonuclear protein imbalance and UPRmt to alleviate lung damage. We also found the protective effect of HO-1 depended on NAD+ and NAD+-mediated mitonuclear communication. Furtherly, the inhibition of the PGC1α/PPARγ signaling exacerbates the septic lung injury by reducing NAD+ levels and repressing the mitonuclear protein imbalance and UPRmt. Altogether, our study certified that HO-1 ameliorated endotoxin-induced acute lung injury by regulating NAD+ and NAD+-mediated mitonuclear communications through PGC1α/PPARγ pathway. The present study provided complementary evidence for the cytoprotective effect of HO-1 as a potential target for preventing and attenuating of endotoxin-induced ALI.

NAD(H)-loaded nanoparticles for efficient sepsis therapy via modulating immune and vascular homeostasis.

Sepsis is a life-threatening organ dysfunction responsible for nearly 270,000 deaths annually in the United States alone. Nicotinamide adenine dinucleotide (NAD+), an immunomodulator, can potentially treat sepsis; however, clinical application of NAD+ is hindered by its inability to be directly taken up by cells. To address this challenge, a family of nanoparticles (NPs) loaded with either NAD+ or the reduced form of NAD+ (NADH), hereafter NAD(H)-loaded NPs, were engineered to enable direct cellular transport and replenishment of NAD(H). The NAD(H)-loaded NPs improved cellular energy supply, suppressed inflammation and prevented inflammation-induced cell pyroptosis and apoptosis. Therefore, the NPs can help maintain immune homoeostasis and vascular function, two key factors in the pathogenesis of sepsis. The NAD(H)-loaded NPs demonstrated excellent therapeutic efficacies in treating endotoxemia and multidrug-resistant pathogen-induced bacteremia. In addition, the NAD(H)-loaded NPs prevented caecal ligation and puncture-induced multiorgan injury and improved outcomes of secondary Pseudomonas aeruginosa infections following caecal ligation and puncture, thus potentially leading to a highly innovative and translational approach to treat sepsis efficiently and safely.

Nicotinamide Riboside-Conditioned Microbiota Deflects High-Fat Diet-Induced Weight Gain in Mice.

The gut microbiome plays an essential role in host energy homeostasis and influences the development of obesity and related conditions. Studies demonstrate that nicotinamide riboside (NR) supplementation for diet-induced obesity (DIO) reduces weight gain and increases energy expenditure in mice. NR is a vitamin B3 derivative and an NAD+ precursor with potential for treating human diseases arising from mitochondrial degeneration, including obesity and type 2 diabetes. Gut bacteria produce vitamin B3 in the colon and are capable of salvaging and metabolizing vitamin B3 and its derivatives. However, it is unknown how dietary supplementation of NR alters the microbiome and if those alterations contribute to deflection of weight gain. In this study, we fed C57BL/6J male mice a high-fat diet (HFD) supplemented with or without NR and performed a fecal material transfer (FMT) to establish a link between NR-conditioned microbiota and NR-induced deflection of weight gain. FMT from NR-treated donors to naive mice fed a HFD was sufficient to deflect weight gain by increasing energy expenditure. We also investigated the effects of NR on the microbiome by using metagenomics sequencing. We found that NR-treated mice displayed an altered gut microbial composition relative to controls and that fecal transplant resulted in a distinct functional metabolic profile characterized by enrichment of butyrate-producing Firmicutes. NR-treated donors and subsequent FMT recipients share a similar enrichment of metagenomic biomarkers relative to controls. These findings suggest that microbial factors contribute to the beneficial effects of dietary NR supplementation, which may be useful to enhance the therapeutic effects of NR. IMPORTANCE With obesity and type 2 diabetes (T2D) at epidemic levels, we need to understand the complex nature of these diseases to design better therapeutics. The underlying causes of both obesity and T2D are complex, but both are thought to develop, in part, based on contributions from the gut microbiota. Nicotinamide riboside is a gut-derived vitamin B3 derivative and NAD+ precursor which has the potential to treat and prevent metabolic disorders by ameliorating mitochondrial dysfunction. Understanding how NR affects the gut microbiome and whether NR-conditioned microbiota contributes to weight loss in the host would (i) improve diagnosis and treatments for obesity and other metabolic pathologies, (ii) tailor treatments to satisfy the needs of each individual moving toward the future of precision medicine, and (iii) benefit other scientific fields that currently investigate the effects of NR in other disease pathologies.

Model of Streptozotocin-nicotinamide Induced Type 2 Diabetes: a Comparative Review.

The aim of the present study was to review the streptozotocin-nicotinamide (STZ-NA) diabetes model. Type 2 diabetes is more prevalent (90-95%) in adults than type 1. Experimentally- induced diabetes models may be established by chemicals, viral agents, insulin antibodies, surgery, etc. The most advisable and prompt method to induce diabetes is using chemicals, and STZ and alloxan are widely used chemicals. STZ has proven to be a better diabetogenic agent than alloxan because alloxan has many drawbacks, as it induces only type 1 diabetes, has a high mortality rate in rats, and causes ketosis in animals. Moreover, it has lesser selectivity towards ß-cells, and the diabetes-induced is reversible. STZ can be used to induce both type 1 and type 2 diabetes. It is noted that the genotoxic behavior of STZ in animals is accomplished through a reduction of nicotinamide adenine dinucleotide (NAD+) in pancreatic ß-cells via the GLUT2 (Glucose transporter 2), which can cause cellular damage by DNA (Deoxyribonucleic acid) strand breaks that lead to cell death. NA is a biochemical precursor of NAD+, and it is a poly-ADP-ribose-polymerase-1 (PARP- 1) inhibitor. NAD+ is an important redox reaction co-enzyme for the production of adenosine triphosphate (ATP) and many other metabolic pathways. Extreme DNA damage contributes to the over-activation of PARP-1, loss of cellular resources, and necrotic cells death. Some studies have expressed that NA can protect pancreatic ß-cells against the severe cytotoxicity of STZ. The review concluded that the STZ-NA model is dependent on the competency of NA to attain partial protection against the ß-cytotoxic essence of STZ to induce type-2 diabetes.

Emerging potential benefits of modulating NAD+ metabolism in cardiovascular disease.

Nicotinamide adenine dinucleotide (NAD+) and related metabolites are central mediators of fuel oxidation and bioenergetics within cardiomyocytes. Additionally, NAD+ is required for the activity of multifunctional enzymes, including sirtuins and poly(ADP-ribose) polymerases that regulate posttranslational modifications, DNA damage responses, and Ca2+ signaling. Recent research has indicated that NAD+ participates in a multitude of processes dysregulated in cardiovascular diseases. Therefore, supplementation of NAD+ precursors, including nicotinamide riboside that boosts or repletes the NAD+ metabolome, may be cardioprotective. This review examines the molecular physiology and preclinical data with respect to NAD+ precursors in heart failure-related cardiac remodeling, ischemic-reperfusion injury, and arrhythmias. In addition, alternative NAD+-boosting strategies and potential systemic effects of NAD+ supplementation with implications on cardiovascular health and disease are surveyed.

On the safety of reduced nicotinamide adenine dinucleotide (NADH).

The objective of the study was to determine both the toxicity of the stabilized orally absorbable form of nicotinamide adenine dinucleotide (NADH) (ENADA) and the maximum tolerated intravenous dose (MTD) of betaNADH (the reduced form of NADH) in beagle dogs. The administration of the stabilized orally absorbable form of NADH to beagle dogs at dose levels of 20, 100, and 150 mg/kg for 14 days elicited no signs of a toxicological effect. A transitory change in stool formation was observed with the intermediate and high dose in males. There were also apparent increases in adrenal, heart, kidney, liver, brain, and thyroid weights, particularly in males, but none of these changes were considered to be toxicologically significant. In addition, four dogs (two of each sex) received intravenous infusions of 100 mg NADH/kg/day for 4 days, followed by 200 mg NADH/kg/day for 3 days, followed by 500 mg NADH/kg/day for 4 days, and 1000 mg NADH/kg/day on the final day. At the end of the MTD phase, the control animals that had received saline solution in the MTD phase were used to evaluate the potential toxicity of the established MTD. These animals received 500 mg NADH/kg/day for 14 days (fixed dose phase). There were no deaths. At dose levels between 100 and 1000 mg/kg/day, effects on the cardiovascular system and also some evidence of an effect on the central nervous system and on the adrenals were observed. At doses of 500 mg/kg/day and above, food consumption and body weight were reduced. On the basis of the observed changes, the maximum intravenous dose of NADH tolerated by beagle dogs was considered to be 500 mg/kg/day. There were no gross histological findings indicative of toxicity in the organs of tissues examined. Based on these findings, the stabilized orally absorbable form of NADH (ENADA) can be regarded as safe.

Treatment of Alzheimer's disease with stabilized oral nicotinamide adenine dinucleotide: a randomized, double-blind study.

This study was designed to evaluate the effect of stabilized oral reduced nicotinamide adenine dinucleotide (NADH) on cognitive functioning in patients with Alzheimer's disease (AD). NADH is a coenzyme that plays a key role in cellular energy production and stimulates dopamine production. In previous trials NADH has been shown to improve cognitive functioning in patients with Parkinson's disease, depression and AD. The present trial was a randomized, placebo-controlled, matched-pairs, double-blind, 6-month clinical study. Patients with probable AD (n = 26) were randomized to receive either stabilized oral NADH (10 mg/day) or placebo. Twelve pairs of subjects were matched for age and baseline total score on the Mattis Dementia Rating Scale (MDRS) and the Mini Mental State Examination. After 6 months of treatment, subjects treated with NADH showed no evidence of progressive cognitive deterioration and had significantly higher total scores on the MDRS compared with subjects treated with placebo (p < 0.05). Analysis of MDRS subscales revealed significantly better performance by NADH subjects on measures of verbal fluency (p = 0.019), visual-constructional ability (p = 0.038) and a trend (p = 0.08) to better performance on a measure of abstract verbal reasoning. There were no differences between groups in measures of attention, memory, or in clinician ratings of dementia severity (Clinical Dementia Rating). Consistent with earlier studies, the present findings support NADH as a treatment for AD.

Treatment of Parkinson's disease with NADH.

It has earlier been claimed that clinical improvement of patients with Parkinson's disease is obtained by treatment with NADH. This has to be verified by double-blind, clinical studies and measurement of biochemical effects of the treatment. In a double blind study five patients with clinically moderate Parkinson's disease were treated with NADH, 25 mg, given intravenously once a day for four days. Then they were given 25 mg NADH intramuscularly after 2 and 4 weeks. Disability scores were determined before each treatment and two weeks after the final injection. A control group (n = 4) with the same degree of Parkinson's disease obtained sodium chloride with the same schedule. According to the Unified Parkinson's Disease Rating Scale a tendency to clinical improvement was seen after the iv infusions in both treatment and placebo groups. However, the changes were not statistically significant, and no changes occurred during the following weeks. No changes were found neither in the study nor the control group regarding cerebrospinal fluid concentrations of dynorfin, metenkefalin, somatostatin, hydroxy-methoxy-phenylglycol, homovanillic acid and 5-hydroxyindole acetic acid. The results indicate that no great changes are obtained after short-term treatment of parkinsonian patients with NADH, neither clinically nor biochemically.

Recent advances in pharmacological therapy of Parkinson's disease.

The discovery of a selective striatal dopamine deficiency in Parkinson's disease has led to dopamine replacement therapies including L-DOPA, dopamine full and partial agonists, and MAO-B inhibitors. The development of new compounds and alternative methods of drug delivery may be able to overcome the long-term side effects of the established therapies. Overactivity of central glutamatergic systems appears to be important in the pathophysiology of the disorder and provides the rationale for the use of glutamate antagonists. Recent studies emphasize the significance of oxidative stress and free radical formation in the pathogenesis of Parkinson's disease. Future research will focus on improvements in neuroprotective therapy to prevent or slow the rate of progression of the disease. Possible neuroprotective strategies include selective MAO-B inhibitors, iron chelators, and free radical scavengers.

Nicotinamide adenine dinucleotide (NADH)--a new therapeutic approach to Parkinson's disease. Comparison of oral and parenteral application.

The reduced coenzyme nicotinamide adenine dinucleotide (NADH) has been used as medication in 885 parkinsonian patients in an open label trial. About half of the patients received NADH by intravenous infusion, the other part orally by capsules. In about 80% of the patients a beneficial clinical effect was observed: 19.3% of the patients showed a very good (30-50%) improvement of disability, 58.8% a moderate (10-30%) improvement. 21.8% did not respond to NADH. Statistical analysis of the improvement in correlation with the disability prior to treatment, the duration of the disease and the age of the patients revealed the following results: All these 3 parameters have a significant although weak influence on the improvement. The disability before the treatment has a positive regression coefficient (t value < 0.01). The duration of the disease has a negative regression coefficient (< 0.01) and so has the age a negative regression coefficient (t value < 0.05). In other words younger patients and patients with a shorter duration of disease have a better chance to gain a marked improvement than older patients and patients with longer duration of the disease. The orally applied form of NADH yielded an overall improvement in the disability which was comparable to that of the parenterally applied form.