Safety of stabilized, orally absorbable, reduced nicotinamide adenine dinucleotide (NADH): a 26-week oral tablet administration of ENADA/NADH for chronic toxicity study in rats.

The safety of the stabilized, orally absorbable form of reduced nicotinamide adenine dinucleotide (NADH), known under the brand name ENADA, was investigated over a period of 26 weeks. Eighty healthy rats (40 males and 40 females) were divided into two groups. One tablet ENADA/NADH 5 mg per day was administered orally to one group while identical-looking white tablets not containing NADH (placebo) were given to the other group. The following parameters were statistically analyzed: body weight, body weight gain, food consumption, hematology, clinical chemistry, organ weight and organ histology. Clinical signs and mortality were recorded. There were no deaths associated with the study drug and no treatment-releated clinical signs. No differences in body weight between the placebo and the ENADA-treated males were observed. In the second half of the treatment period (weeks 13-26) females treated with NADH gained significantly (p < 0.05) more body weight than the controls. Food consumption in the treated males was similar to that in controls. From approximately week 15, the treated females consumed up to 10% more food than the controls. No differences were observed between the control and the treated groups in terms of hematology or clinical chemistry parameters. There was no apparent treatment-related effect on urine analysis parameters or on either the absolute or the relative organ weight. Furthermore, no macroscopic evidence of specific target organ toxicity associated with the test drug was observed. Histological findings in the treated rats were generally similar to those in control rats. A daily dose of 5 mg in a rat corresponds to a dose of 175 mg per day in a 70-kg human. This is 175 times the recommended daily dosage of 1 ENADA tablet per day. Hence ENADA/NADH 5 mg tablets can be generally regarded as safe.

NADH stimulates endogenous dopamine biosynthesis by enhancing the recycling of tetrahydrobiopterin in rat phaeochromocytoma cells.

Treatment of Parkinson patients with L-DOPA (3,4-dihydroxy-L-phenylalanine) leads to endproduct inhibition of tyrosine hydroxylase, the key enzyme in dopamine biosynthesis and the enzyme needing tetrahydrobiopterin and iron as cofactors. To overcome this problem an alternative treatment was investigated which attempted to stimulate endogenous dopamine biosynthesis. Incubation of rat PC 12 cells with NADH (beta-nicotinamide adeninedinucleotide) leads to increased dopamine production. We investigated the possibility that this increase of dopamine biosynthesis was due to stimulation of quinonoid dihydropteridine reductase, the enzyme which recycles the inactive dihydrobiopterin to the active tetrahydrobiopterin. The experiments showed that whereas NADH is able to increase dopamine production in PC 12 cells (rat phaeochromocytoma cells, clone PC 12) up to three-fold, no influence is exerted by NADH on pteridine metabolism; neither are tetrahydrobiopterin concentrations nor the de novo-biosynthesis of pteridines from guanosine triphosphate altered by NADH. Further no influence of NADH on protein de novo synthesis of quinonoid dihydropteridine reductase was observed. However, NADH was able to directly increase the catalytic activity of this enzyme. Our results suggest that the stimulation of dopamine biosynthesis by NADH is due to more rapid regeneration of quinonoid dihydrobiopterin to tetrahydrobiopterin.

Monoaminergic neurotransmitters, their precursors and metabolites in brains of Alzheimer patients.

The catecholamines dopamine (DA), noradrenaline (NA) and adrenaline (A), their aminoacid precursors tyrosine (Tyr), L-3,4-dihydroxyphenylalanine (L-DOPA), two of their metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxy phenyl glycol (MHPG), serotonin (5-HT) and its precursor tryptophan (Trp), were measured by high pressure liquid chromatography (HPLC) with electrochemical detection in seven regions (globus pallidus, putamen, nucleus amygdalae, nucleus caudatus, substantia nigra, gyrus cinguli and raphe) of postmortem brains from eight histologically verified cases with Alzheimer's disease (AD) and six histologically normal controls. Concentrations of L-DOPA, DA, DOPAC, NA and 5-HT were significantly reduced, while Tyr and MHPG concentrations were significantly increased in AD versus control patients. The concentrations of Trp and A in AD patients were not significantly different from controls. Furthermore, for most brain regions examined, significant negative correlations between Tyr and DA as well as between NA and MHPG levels were found. These data confirm and extend findings of monoaminergic systems disturbances in AD, emphasize the significance of dopaminergic deficit for AD and suggest that in pharmacotherapy of AD, attempts to restore deficits of the transmitter systems should be directed to the monoaminergic, in particular the dopaminergic system.

Coenzyme nicotinamide adenine dinucleotide: new therapeutic approach for improving dementia of the Alzheimer type.

The Coenzyme nicotinamide adenine dinucleotide (NADH) has been used as medication in 17 patients suffering from dementia of the Alzheimer type in an open label trial. In all patients evaluated so far, an improvement in their cognitive dysfunction was observed. Based on the minimental state examination, the minimum improvement was 6 points and the maximum improvement 14 points with a mean value of 8.35 points. The improvement on the basis of the global deterioration scale (GDS) was a minimum of 1 point and a maximum of 2 points with a mean value of 1.82. The duration of therapy was between 8 and 12 weeks. No side effects or adverse effects have been reported from the patients or their caregivers during the observation period which is, in some patients, more than a year. This open label trial represents a pilot study from which no definitive conclusion can be drawn. A double-blind placebo controlled study is necessary to demonstrate the clinical efficacy of NADH. The planning and the fulfillment of all requirements for such a study are in progress.

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.

Stimulation of dopamine biosynthesis in cultured PC 12 phaeochromocytoma cells by the coenzyme nicotinamide adeninedinucleotide (NADH).

The activity of the tyrosine hydroxylase, the enzyme which is diminished in the brains of Parkinson patients, has been measured in cultured PC 12 rat phaeochromocytoma cells. In the same way dopamine content in the medium after incubating these cells with or without NADH was assayed. The experiment shows that NADH is able to increase the activity of the tyrosine hydroxylase and dopamine - production in PC 12 cells up to 6 times. The results provide evidence that NADH is able to stimulate dopamine - biosynthesis directly.

Improvement of disability and akinesia of patients with Parkinson's disease by intravenous iron substitution.

Akinetic crises are one of the problems arising in patients with Parkinson's disease in particular after long term treatment with levo-dihydroxyphenylalanine (L-DOPA). They are characterized by severe disability to move. Increasing dosages of L-DOPA and decarboxylase or monoaminooxidase inhibitors do not improve these symptoms. Intravenously applied iron in the form of a ferri-ferro-complex exhibits a considerable benefit for all patients treated so far. They regained a remarkable mobility. Their disability score dropped from up to 90 percent down to 30 percent. The effect is dosage-dependent, and withdrawal of iron will lead again to akinetic crises.

Iron, a new aid in the treatment of Parkinson patients.

One of the problems in treating Parkinson patients is the so called "off-effect" which occurs after long term treatment with L-DOPA. Off-effects are characterized by severe rigor and akinesia. Increasing dosages of L-DOPA and decarboxylase- or monoaminooxidase-inhibitors do not improve these symptoms. Intravenously applied iron--in form of a ferri-ferro-complex--exhibited a considerable benefit for all patients treated so far. They regained a remarkable mobility. Their disability score dropped from up to 90% down to 30%. The effect of iron is dosage-dependent and lasts 24 to 48 hours.