Ninjinyoeito ameliorates anorexia and changes in peptide YY and ghrelin levels of cisplatin-treated mice.

We explored the effect of Ninjinyoeito (NYT) on cisplatin-induced anorexia, which reduces cancer patient survival. Both gastrointestinal motility and plasma concentrations of gastrointestinal peptides were assessed. Nine-week-old ICR female mice received intraperitoneal cisplatin injections (10 mg/kg) and daily oral NYT doses of 300 mg/kg (NYT300) or 1000 mg/kg (NYT1000). Plasma levels of gastrointestinal peptides were measured at 3 and 6 days after cisplatin injection. Gastrointestinal motility was assessed by analyzing the concentration of phenol red marker within sections of the gastrointestinal tract. Cisplatin-injected mice showed a decrease in daily food intake, but this effect was attenuated on day 5 with NYT1000 administration. Although plasma ghrelin levels were reduced on day 3 in cisplatin-treated mice, NYT1000 administration ameliorated this decrease. However, there were no differences in ghrelin levels among all groups on day 6. Levels of peptide YY (PYY) were elevated in the plasma of cisplatin-injected mice on days 3 and 6. Administration of NYT300 and NYT1000 suppressed the increase in PYY levels on day 6 but not on day 3. Gastrointestinal motility was impaired on day 6 in cisplatin-treated mice, but NYT1000 administration attenuated this effect. Our results suggest that NYT improves cisplatin-induced anorexia by suppressing alterations in ghrelin and PYY levels and by increasing gastrointestinal motility. Therefore, NYT may be a promising candidate for alleviating cisplatin-induced anorexia.

The Effects of Ninjinyoeito on Impaired Spatial Memory and Prefrontal Cortical Synaptic Plasticity through α-Amino-3-hydroxy-5-4-isoxazole Propionic Acid Receptor Subunit in a Rat Model with Cerebral Ischemia and ß-Amyloid Injection.

Ninjinyoeito (NYT), a traditional Japanese medicine, is effective for improving physical strength and treating fatigue and anorexia. Recently, a clinical report revealed that NYT ameliorates cognitive dysfunction in Alzheimer's disease (AD) patients, although the mechanisms remain unclear. AD is a neurodegenerative disorder accompanied by a progressive deficit in memory. Current therapeutic agents are largely ineffective in treating cognitive dysfunction in AD patients. In this study, we investigated the effects of NYT on spatial memory impairment in a rat model of dementia. Rats were prepared with transient cerebral ischemia and intraventricular injection of ß-amyloid1-42 for 7 days (CI + Aß). NYT was orally administered for 7 days after cerebral ischemia. We evaluated spatial memory using the Morris water maze and investigated the expression of α-amino-3-hydroxy-5-4-isoxazole propionic acid receptor subunits, the phosphorylation level of glutamate receptor A (GluA)1 at serine sites S831 and S845, and the Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the hippocampus and prefrontal cortex of CI + Aß rats. In the CI + Aß rats, NYT treatment shortened the extended time to reach the platform. However, NYT did not restore the decrease in the hippocampal GluA1, GluA2, or CaMKII expression but increased prefrontal cortical phosphorylation levels of S845-GluA1 and CaMKII. Therefore, NYT may alleviate spatial memory impairment by promoting glutamatergic transmission involved in the phosphorylation of S845-GluA1 and CaMKII in the prefrontal cortex of CI + Aß rats. Our results suggest that NYT is a valuable treatment for AD patients.

Ninjinyoeito Prevents Onset of Depression-Like Behavior and Reduces Hippocampal iNOS Expression in Senescence-Accelerated Mouse Prone 8 Mice.

Late-life depression is a globally prevalent disorder. Ninjinyoeito (NYT), a traditional Japanese herbal medicine, attenuates depressive symptoms in older patients. However, the mechanisms underlying the antidepressive effect of NYT are unknown. In this study, we investigated the mechanism of the action of NYT using senescence-accelerated mouse prone 8 (SAMP8) mice, which exhibit accelerated aging. SAMP8 mice were treated with NYT starting at 12 weeks of age. Twelve-week-old SAMP8 mice did not show prolonged immobility time in the tail suspension test compared with age-matched SAMR1 mice (normal aging control). At 34 weeks of age, vehicle-treated SAMP8 mice displayed prolonged immobility time compared with SAMR1 mice. NYT-treated SAMP8 mice showed a shorter immobility time than that of vehicle-treated SAMP8 mice. Notably, NYT decreased hippocampal inducible nitric oxide synthase (iNOS) expression in SAMP8 mice. There was no difference in iNOS expression between SAMR1 and vehicle-treated SAMP8 mice. Subchronic (5 days) administration of an iNOS inhibitor, 1400 W, shortened the immobility time in SAMP8 mice. These results suggest that NYT prevents an increase in immobility time of SAMP8 mice by decreasing iNOS levels in the hippocampus. Therefore, the antidepressive effect of NYT in older patients might be mediated, at least in part, by the downregulation of iNOS in the brain. Our data suggest that NYT is useful to prevent the onset of depression with aging.