The effects of sho-saiko-to-go-keishi-ka-shakuyaku-to (TJ-960) on ischemia-induced changes of brain acetylcholine and monoamine levels in gerbils

Dietary flavonoids as potential neuroprotectants

There is an increasing awareness of the role of certain nutritional components, including dietary flavonoids found in fruit, vegetables and beverages, in the maintenance of health and prevention of chronic diseases. In this regard, recent studies highlight an exciting role with respect to their potential neuroprotective actions, in particular towards deficits commonly observed with aging, such as reduced performance of cognitive, memory and learning tasks. These neurological functions, and possible mechanisms involved in controlling them, can be influenced by supplementation of single dietary flavonoids, or as part of a flavonoid-rich preparation. With this, a renewed emphasis is aimed at further understanding their modes and sites of action. Moreover a common theme among many in vitro studies examining mechanisms of neuroprotection is the failure to include biologically relevant metabolites of the flavonoids known to enter the circulation, and thus most likely to be bioavailable to cells and tissues. This oversight will ultimately influence the mechanisms of action proposed to explain the neuroprotection observed in animals and human studies. As such, emerging findings suggest a variety of potential mechanisms of action of flavonoids and their bioavailable metabolites in cytoprotection against oxidative stress, which may be independent of conventional antioxidant reducing activities. Such mechanisms might involve their interaction with cell signalling cascades, their influence on gene expression and the down regulation of pathways leading to cell death.

Protective effect of oren-gedoku-to against induction of neuronal death by transient cerebral ischemia in the C57BL/6 mouse

We examined the neuroprotective effects of oren-gedoku-to (TJ15), a herbal medicine, after transient forebrain ischemia. Transient forebrain ischemia was induced by occlusion of both common carotid arteries for 15 min in C57BL/6 mice treated with TJ15. In the control ischemic group without TJ15 treatment, histologic examination of brain tissue collected seven days after reperfusion showed death of pyramidal cells in CA2-3 area of the hippocampus, unilaterally or bilaterally. In mice treated with oral TJ15 (845 mg/kg/day) for five weeks, the frequency of ischemic neuronal death was significantly lower. Immunohistochemistry for Cu/Zn-superoxide dismutase (Cu/Zn-SOD) showed strongly reactive astrocytes in the hippocampus of ischemic mice treated with TJ15. Damage to nerve cells by free radicals plays an important role in the induction of neuronal death by ischemia-reperfusion injury. Our results suggest that TJ15 protects against ischemic neuronal death by increasing the expression of Cu/Zn-SOD and suggest that oren-gedoku-to reduces the exposure of hippocampal neurons to oxidative stress.

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.

Effects of long-term recovery from transient cerebral ischemia in rat brain: tissue levels of acetylcholine, monoamines, and their metabolites

Concentrations of acetylcholine and the monoaminergic neurotransmitters dopamine, serotonin and their respective metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxy-phenylacetic acid (HVA), 5-hydroxyindolacetic acid (5-HIAA) and choline were simultaneously determined in the corpus striatum of rats after 15 min. complete cerebral ischemia (CCI) and in different intervals (1, 24, 48, 72, 96 hours) of postischemic cerebral reperfusion. Results were compared to respective sham-operated control animals. After 15 min. CCI acetylcholine concentration decreased to 15%, and dopamine concentration to 56% of the control values. The metabolite levels of DOPAC decreased to 40% and HVA to 64% of the control values. Acetylcholine, dopamine, serotonin and choline concentrations were not changed significantly after reperfusion. The metabolites HVA and 5-HIAA showed their maximum increases after 1 and 24 hours of reperfusion, additionally HVA was decreased both, after 72 and 96 hours of reperfusion. The data indicate that surprisingly little permanent damage could be caused by a 15 min. ischemia in the striatum. Tissue levels of the neurotransmitters appeared differentially altered but similarly regulated during ischemia and subsequent recirculation. Acetylcholine and dopamine levels decreased profoundly during ischemia. However, acetylcholine levels could be compensated rapidly during reperfusion, whereas the dopaminergic system showed a long-lasting change in its turnover rate. Although serotonin levels were unaffected by CCI, there was an increase of its presumed turnover rate during reperfusion.

Age-related increases in superoxide dismutase activity and thiobarbituric acid-reactive substances: effect of bio-catalyzer in aged rat brain

This study describes, using electron spin resonance spectrometry/spin trapping technique, the increase superoxide dismutase (SOD) activity in the mitochondrial and cytosolic fraction of the cortex, midbrain, pons-medulla oblongata and cerebellum, and in thiobarbituric acid-reactive substances (TBARS) in the cortex, cerebellum and hippocampus of the aged rats. The results show that corresponding to the increased life span and improved physical conditions observed after peroral long-term treatment with Bio-catalyzer, a commercial natural fermented health food supplement marketed in Japan and in the Philippines and earlier reported to be a hydroxyl radical scavenger with weaker scavenging activity on superoxide radical (O-2), SOD which is involved in the metabolic degradation of O-2 was further increased, whereas TBARS decreased. These findings suggest that the increased SOD activity in the brain as a defense mechanism against age-related accumulation of reactive oxygen species, in particular superoxide radicals, was enhanced with Bio-catalyzer treatment while age-related peroxidation of neuronal membrane, as measured by TBARS, was decreased.

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

Bifemelane hydrochloride (bifemelane), idebenone and indeloxazine hydrochloride (indeloxazine) are used clinically to reduce apathy and other emotional disturbances in patients with cerebrovascular disease. In gerbil brains, ischemia affects many monoaminergic neurotransmitters and their metabolites. In the present study, the effects of treatment with bifemelane, idebenone and indeloxazine on ischemia-induced changes in monoamines and their metabolites were studied in ischemic gerbil brains. Although these drugs had no effect on the monoaminergic neurotransmitters or their metabolites in sham-operated animals, in the ischemic brains both dopamine and serotonin turnovers were abnormal after idebenone or indeloxazine treatment. Bifemelane, in contrast, tended to correct the ischemia-induced changes in the dopaminergic and serotonergic systems in the cerebral cortex, hippocampus and thalamus + midbrain. From the present results and those in previous reports, we conclude that bifemelane is more appropriate than idebenone or indeloxazine as a treatment for the ischemia-induced changes in monoaminergic neurotransmitter systems.