Administration of Ginseng radix decreases nitric oxide synthase expression in the hippocampus of streptozotocin-induced diabetic rats.

Nitric oxide (NO) is synthesized from L-arginine by nitric oxide synthase (NOS). Alternation of NOS expression is implicated in the pathogenesis of numerous secondary complications of diabetes. Aqueous extract of Ginseng radix has traditionally been used for the various disorders including diabetes. In this study, the effect of Ginseng radix on the NOS expression in the hippocampus of streptozotocin (STZ)-induced diabetic rats was investigated via nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Enhanced NOS expression was detected in the hippocampus of diabetic rats and administration of Ginseng radix suppressed NOS expression. Ginseng radix may aid the treatment of central nervous system complications in diabetes.

Effect of acupuncture on nitric oxide synthase expression in cerebral cortex of streptozotocin-induced diabetic rats.

Effect of acupuncture on the expressions of nitric oxide synthase (NOS) and neuronal NOS (nNOS) in the cerebral cortex of streptozotocin (STZ)-induced diabetic rats was investigated. Animals were divided into four groups; the control group, the nondiabetic and acupunctured group, the STZ-induced-diabetes group, and the STZ-induced diabetic and acupunctured group. To produce the diabetic animal model, a single intraperitoneal injection of STZ (50 mg/kg) was given to each animal; animals of the nondiabetic groups received equivalent amounts of normal saline, also via intraperitoneal injection. From the results, acupuncture was shown to increase the numbers of nicotinamide adenine dinucleotide phosphate-diaphorase-positive and nNOS-positive neurons in STZ-induced diabetic rats. From the present study, it may be suggested that acupuncture modulates NOS and nNOS expressions in the cerebral cortex under diabetic conditions.

Acupuncture increases nitric oxide synthase expression in hippocampus of streptozotocin-induced diabetic rats.

In the present study, the effect of acupuncture at Zusanli acupoint on nitric oxide synthase (NOS) expression in the hippocampus of streptozotocin (STZ)-induced diabetic rats was investigated via nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Animals were divided into four groups: the control group, the nondiabetic and acupunctured group, the STZ-induced diabetes group, and the STZ-induced diabetes and acupunctured group. From the results, NADPH-d-positive neurons in the hippocampus were decreased in STZ-induced diabetic rats, while acupuncture increased NOS expression significantly under diabetic conditions. In the present study, it can be suggested that acupuncture treatment may modulate NOS activity in the hippocampus under diabetic conditions.

Treadmill exercise suppresses diabetes-induced increment of neuropeptide Y expression in the hypothalamus of rats.

Diabetes mellitus is a metabolic disorder with serious sequelae in humans. Hyperphagia is a characteristic symptom of diabetes and is a central nervous system-mediated disorder. Neuropeptide Y (NPY) is a 36-amino-acid peptide and is concentrated in the hypothalamus which is an appetite-regulating area. NPY is known to stimulate appetite and decrease energy expenditure. In the present study, the effect of treadmill exercise on the hypothalamic NPY expression in rats with streptozotocin (STZ)-induced diabetes was investigated via immunohistochemistry. Enhanced NPY expression in the paraventricular nucleus and arcuate nucleus was observed in the STZ-induced diabetic rats. Treadmill exercise suppressed a diabetes-induced increase of NPY expression. The present results suggest the possibility that treadmill exercise inhibits diabetes-induced increment of the desire for food.

Effect of ginseng radix on c-Fos expression in the hippocampus of streptozotocin-induced diabetic rats.

Aqueous extracts of Ginseng radix have traditionally been used in the treatment of diabetes mellitus. In the present study, the effect of Ginseng radix on c-Fos expression in the hippocampus of streptozotocin (STZ)-induced diabetic rats was investigated via immunohistochemistry. Decreased c-Fos expression in the CA regions of the hippocampus was observed in STZ-induced diabetes, and administration of Ginseng radix enhanced the STZ-induced inhibition of c-Fos expression both dose- and duration-dependently. These results suggest that hyperglycemia-induced suppression of Fos expression may trigger the diabetes-induced disruption of hippocampal information processing and that Ginseng radix may alleviate this diabetes-induced disturbance in hippocampal functions.

Effects of Paeonia radix on 5-hydroxytryptamine synthesis and tryptophan hydroxylase expression in the dorsal raphe of exercised rats.

Paeonia radix is the root of Paeonia japonica MIYABE, a perennial plant classified in the family Paeoniaceae. In the present study, the effects of Paeonia radix on performance in treadmill exercise, and 5-hydroxytryptamine (5-HT) synthesis and tryptophan hydroxylase (TPH) expression in the dorsal raphe were investigated. Time to exhaustion in treadmill exercise was increased and exercise-induced increases in 5-HT synthesis and TPH expression in the dorsal raphe were shown to be suppressed by Paeonia radix treatment; 5-HT synthesis and TPH expression were inhibited by Paeonia radix treatment under resting conditions as well. In sum, treatment with Paeonia radix, inhibiting 5-HT synthesis and TPH expression, may bring about reduced fatigue, both during exercise and the resting state.

Ginseng radix increases cell proliferation in dentate gyrus of rats with streptozotocin-induced diabetes.

In the present study, the effect of Ginseng radix on cell proliferation in the dentate gyrus of rats with streptozotocin-induced diabetes was investigated via immunohistochemistry. Aqueous extract of Ginseng radix was shown to exert no significant effect on weight in normal rats, while it prevented weight loss in rats with streptozotocin-induced diabetes. Cell proliferation in the dentate gyrus of diabetic rats was increased by Ginseng radix treatment, but it had no effect on cell proliferation in normal rats. These results suggest that Ginseng radix may help in improve the central nervous system complications of diabetes mellitus.