Comparison of the effects of bifemelane hydrochloride, idebenone and indeloxazine hydrochloride on ischemia-induced changes in brain monoamines and their metabolites in gerbils

Treatment with Bifemelane for Optic Nerve Damage following High Intraocular Pressure in Rat Eyes

This study found that pretreatment with 4-(o-benzylphenoxy)-N- methylbuty-lamine hydrochloride (bifemelane hydrochloride, Celeport) reduced ischemia-reperfusion injury in rat eyes. Bifemelane (25 mg/kg) was injected intraperitoneally 30 minutes before an ischemic insult, then acute ischemia of the retina and optic disc was induced by increasing intraocular pressure to 110 mmHg for 45 minutes. After one week, the axonal count of the optic nerve was investigated using electron microscopy. The control group consisted of vehicle-treated eyes which received normal saline. The axon count was 93.4 +/- 7.9 for the bifemelane treated group, and 79.2 +/- 6.4 for the controls. The axon count in the treated group was significantly higher. These results suggest that bifemelane, which prevents cerebral nerve cell damage from ischemia, can reduce ischemic retinal nerve cell injury.

Bifemelane hydrochloride protects against cytotoxicity of hydrogen peroxide on cultured rat neuroblastoma cell line

Free radicals are involved in neuronal damage. Bifemelane hydrochloride has been reported to protect neural tissues against ischemic damage and age-related neurodegeneration. We examined the protective effects of bifemelane HCl and the relation between its effectiveness and free radical formation in hydrogen peroxide (H2O2)-induced cytotoxicity using cultured rat neuroblastoma cell line (B50). Cytotoxicity was examined by using the lactate dehydrogenase (LDH) assay and cell viability by the WST-1 assay. H2O2 reduced the survival of B50 cells in a dose-dependent manner, and treatment of these cells with 75 microM or 100 microM H2O2 reduced their viability by 50% relative to the control group. B50 cells were treated with 5 or 10 microM bifemelane for 2 days followed by treatment with 75 microM or 100 microM H2O2. H2O2 cytotoxicity was reduced by pretreatment with bifemelane. We also examined the effect of bifemelane on lipid peroxide formation in B50 cells using thiobarbituric acid reactive substances assay. Pretreatment of B50 cells with 10 microM bifemelane for 2 days reduced lipid peroxide formation to approximately 54% of the control group. Our results suggest that bifemelane hydrochloride provides a protective effect against H2O2 cytotoxicity partly due to its anti-oxidative properties.

Chronic administration of Oren-gedoku-to (TJ15) inhibits ischemia-induced changes in brain indoleamine metabolism and muscarinic receptor binding in the Mongolian gerbil

We examined the effect of Oren-gedoku-to (TJ15), which is a traditional herbal Kampo prescription used as an anti-cerebral apoplexy agent on these changes. Chronic pre- and post-ischemia TJ15 oral administration almost completely abolished the ischemia-induced muscarinic receptor reduction and 5-hydroxyindoleacetic acid level increase. These results suggest that TJ15 prevents cholinergic synaptic dysfunction and serotonergic presynaptic hyperactivity induced by transient ischemia.

Diet-induced changes in serum cholesterol concentrations do not alter tryptophan hydroxylation rate or serotonin concentrations in gerbil brain

The relationship between serum cholesterol concentrations and serotonin synthesis rate in brain was examined in Mongolian gerbils chronically fed diets containing 20% fat (safflower oil, beef tallow or butterfat) with or without added cholesterol (0.5%, dry weight). After 22 days on these diets, circulating cholesterol concentrations ranged between approximately 1.5 and approximately 20 mumol/ml. Despite this enormous range, in vivo tryptophan hydroxylation rate, and serotonin and 5-hydroxyindoleacetic acid concentrations in cerebral cortex, hypothalamus and brainstem did not differ significantly among the diet groups. Tryptophan concentrations in serum and brain were also unaffected. These results do not support the hypothesis that the link between depression, suicide and violent deaths and below-normal or reduced serum cholesterol concentrations in humans involves an alteration in serotonin synthesis and/or release by brain neurons.

Preventive effects of bifemelane hydrochloride on decreased levels of muscarinic acetylcholine receptor and its mRNA in a rat model of chronic cerebral hypoperfusion

Changes in muscarinic acetylcholine receptor (mACh-R) binding and muscarinic cholinergic m1 receptor (m1-R) mRNA levels were determined in a rat model of cerebral hypoperfusion in which hypoperfusion was induced by permanent bilateral occlusion of the common carotid arteries. After 6 weeks of hypoperfusion, mACh-R binding activity was significantly reduced in the frontal cortex (79.0 percent, P <0.01), striatum (74.2 percent, P < 0.01) and hippocampus (78.6 percent, P < 0.01), and the m1-R mRNA levels in the frontal cortex (86.6 percent, P < 0.05) and striatum (89.4 percent, P < 0.05) compared with sham-operated control. Repeated administration of bifemelane hydrochloride (15 mg/kg/day, p.o., once a day from the day of operation for 6 weeks) prevented the hypoperfusion-induced loss of mACh-R binding and m1-R mRNA levels above described. Since the central cholinergic systems play an important role in learning and memory, these findings suggest that bifemelane hydrochloride is useful to treat and/or prevent vascular dementia which is closely related to cerebral hypoperfusion.

Inhibitory effect of bifemelane on superoxide generation by activated neutrophils measured using a simple chemiluminescence method

We evaluated the effect of 4-(2-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane hydrochloride) on superoxide production by human neutrophils using an MCLA-dependent chemiluminescence assay. Bifemelane hydrochloride dose-dependently inhibited superoxide production by neutrophils stimulated with phorbol myristate acetate, opsonized zymosan, or N-formyl-methionyl-leucyl-phenylalanine, while it had no effect on superoxide production by a hypoxanthine-xanthine oxidase system. These results indicate that bifemelane hydrochloride does not have a scavenging effect, but has an inhibitory effect on superoxide generation by neutrophils. Although this drug is commonly used for treating chronic cerebral infarction, it may also have a protective effect on acute ischemia/reperfusion injury.