Characterization and pharmacokinetic evaluation of microcomposite particles of alpha lipoic acid/hydrogenated colza oil obtained in supercritical carbon dioxide.

The work reported here is an extension of our previous findings in which supercritical composite particles (SCP) of alpha lipoic acid (ALA) masked with hydrogenated colza oil (HCO) named as ALA/HCO/SCP were obtained by the modified particles from gas-saturated solutions (PGSS) process in supercritical carbon dioxide in order to obscure the unpleasant taste and odor of ALA. The masking effect on ALA/HCO/SCP was compared with the widely used mechano-chemically masked formulation of ALA and HCO named as MC-50F. In the present study, ALA/HCO/SCP particles were found to have a significant improvement in regard to bitterness, numbness, and smell compared to ALA bulk powders suggesting they were well coated. The pharmacokinetic parameters for ALA/HCO/SCP and ALA bulk powder gave similar values but were significantly different from those of MC-50F. The amount of ALA absorbed into the body, in the administered ALA/HCO/SCP, was comparable to that absorbed by ALA bulk powder, whereas about half portion of ALA of the MC-50F was not absorbed, because the ALA/HCO/SCP particles were small enough and the particles of MC-50F were relatively large and had smaller specific surface area. Therefore, this study suggested a newly masked candidate may offer functional particles with maintained efficacy.

Goreisan Prevents Brain Edema after Cerebral Ischemic Stroke by Inhibiting Aquaporin 4 Upregulation in Mice.

BACKGROUND: Aquaporin 4 (AQP4) is a water-selective transport protein expressed in astrocytes throughout the central nervous system. AQP4 level increases after cerebral ischemia and results in ischemic brain edema. Brain edema markedly influences mortality and motor function by elevating intracranial pressure that leads to secondary brain damage. Therefore, AQP4 is an important target to improve brain edema after cerebral ischemia. The Japanese herbal Kampo medicine, goreisan, is known to inhibit AQP4 activity. Here, we investigated whether goreisan prevents induction of brain edema by cerebral ischemia via AQP4 using 4-hour middle cerebral artery occlusion (4h MCAO) mice. METHODS: Goreisan was orally administered at a dose of 500 mg/kg twice a day for 5 days before MCAO. AQP4 expression and motor coordination were measured by Western blotting and rotarod test, respectively. RESULTS: Brain water content of 4h MCAO mice was significantly increased at 24 hours after MCAO. Treatment with goreisan significantly decreased both brain water content and AQP4 expression in the ischemic brain at 24 hours after MCAO. In addition, treatment with goreisan alleviated motor coordination deficits at 24 hours after MCAO. CONCLUSIONS: The results of this study suggested that goreisan may be a useful new therapeutic option for ischemic brain edema.

Gas-saturated solution process to obtain microcomposite particles of alpha lipoic acid/hydrogenated colza oil in supercritical carbon dioxide.

Alpha lipoic acid (ALA), an active substance in anti-aging products and dietary supplements, need to be masked with an edible polymer to obscure its unpleasant taste. However, the high viscosity of the ALA molecules prevents them from forming microcomposites with masking materials even in supercritical carbon dioxide (scCO2). Therefore, the purpose of this study was to investigate and develop a novel production method for microcomposite particles for ALA in hydrogenated colza oil (HCO). Microcomposite particles of ALA/HCO were prepared by using a novel gas-saturated solution (PGSS) process in which the solid-dispersion method is used along with stepwise temperature control (PGSS-STC). Its high viscosity prevents the formation of microcomposites in the conventional PGSS process even under strong agitation. Here, we disperse the solid particles of ALA and HCO in scCO2 at low temperatures and change the temperature stepwise in order to mix the melted ALA and HCO in scCO2. As a result, a homogeneous dispersion of the droplets of ALA in melted HCO saturated with CO2 is obtained at high temperatures. After the rapid expansion of the saturated solution through a nozzle, microcomposite particles of ALA/HCO several micrometers in diameter are obtained.

Effects of Comb Tooth Cap Medicinal Mushroom, Hericium ramosum (Higher Basidiomycetes) Mycelia on DPPH Radical Scavenging Activity and Nerve Growth Factor Synthesis.

The goal of this study was to evaluate the antioxidant effects of and nerve growth factor (NGF) synthesis caused by Hericium ramosum mycelia. Wild mushroom fruiting bodies were collected from nature to isolate their mycelia. Pieces of H. ramosum fruiting bodies were plated onto 90-mm Petri dishes with potato dextrose agar medium to isolate their mycelia. Antioxidant activity was measured using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activity in vitro; the ethanol extract from H. ramosum mycelia (63.11 µmol Trolox/g) was more potent than that of other mushroom mycelia extracts. There was a proportional relationship (R2 = 0.7929) between DPPH radical scavenging activity and total phenolic content in extracts of different mushroom mycelia. We investigated the ability of H. ramosum mycelia to inducing NGF synthesis in vivo. Oral administration of H. ramosum mycelia significantly increased concentrations of NGF in the hippocampus of intact mice. These results are the first concerning antioxidant activity and NGF synthesis of H. ramosum mycelia. These mushroom mycelia could be useful as food and/or nutritional supplements because of certain biological functions.

Hypothalamic 2-arachidonoylglycerol regulates multistage process of high-fat diet preferences.

BACKGROUND: In this study, we examined alterations in the hypothalamic reward system related to high-fat diet (HFD) preferences. We previously reported that hypothalamic 2-arachidonoylglycerol (2-AG) and glial fibrillary acid protein (GFAP) were increased after conditioning to the rewarding properties of a HFD. Here, we hypothesized that increased 2-AG influences the hypothalamic reward system. METHODS: The conditioned place preference test (CPP test) was used to evaluate HFD preferences. Hypothalamic 2-AG was quantified by gas chromatography-mass spectrometry. The expression of GFAP was examined by immunostaining and western blotting. RESULTS: Consumption of a HFD over either 3 or 7 days increased HFD preferences and transiently increased hypothalamic 2-AG levels. HFD consumption over 14 days similarly increased HFD preferences but elicited a long-lasting increase in hypothalamic 2-AG and GFAP levels. The cannabinoid 1 receptor antagonist O-2050 reduced preferences for HFDs after 3, 7, or 14 days of HFD consumption and reduced expression of GFAP after 14 days of HFD consumption. The astrocyte metabolic inhibitor Fluorocitrate blocked HFD preferences after 14 days of HFD consumption. CONCLUSIONS: High levels of 2-AG appear to induce HFD preferences, and activate hypothalamic astrocytes via the cannabinoid system. We propose that there may be two distinct stages in the development of HFD preferences. The induction stage involves a transient increase in 2-AG, whereas the maintenance stage involves a long lasting increase in 2-AG levels and activation of astrocytes. Accordingly, hypothalamic 2-AG may influence the development of HFD preferences.

Increment of hypothalamic 2-arachidonoylglycerol induces the preference for a high-fat diet via activation of cannabinoid 1 receptors.

The aim of the present study is to examine the relationship between preference for HFD and 2-arachidonoylglycerol (2-AG), endogenous cannabinoid. The 3-day HFD intake induced preference for HFD, which was suppressed by CB1 antagonist, O-2050. Moreover, hypothalamic 2-AG was increased after 3-day HFD intake. Our results show that preference for HFD is induced by activation of CB1 receptors via an increment of 2-AG in hypothalamus.

Trace metal zinc stimulates secretion of antimicrobial peptide LL-37 from Caco-2 cells through ERK and p38 MAP kinase.

Infectious diseases, especially, diarrhoea, are responsible for high mortality rates in developing countries. Zinc supplementation shows beneficial effects against such diseases, but the mechanism of action is poorly understood. Here, we examined whether zinc supplementation can improve mucosal innate immunity through induction of antimicrobial peptide secretion from intestinal epithelial cells. Zinc was found to induce secretion of the antimicrobial peptide LL-37 from Caco-2 cell in a dose (0.63±0.09ng/mL and 0.54±0.06ng/mL at 20µM and 50µM respectively) and time dependent manner. LL-37 secretion increased immediately (1h) after exposure to 20µM Zn (0.29±0.04ng/mL), which continued up to 48h of exposure (0.58±0.05ng/mL). Zinc induces the phosphorylation of ERK and p38 MAP kinase and regulates LL-37 secretion through these MAP kinases. Zinc supplementation may have beneficial effects on mucosal innate immunity via secretion of LL-37.

Ameliorating effects of Kangen-karyu on neuronal damage in rats subjected to repeated cerebral ischemia.

We previously reported that 21-day (14-day pre-ischemic and 7-day post-ischemic) treatment with Kangen-karyu (KGKR) improved spatial memory impairment and hippocampal neuronal death induced by repeated cerebral ischemia (2 x 10-min, 1-h interval) in rats. In the present study, we examined the effect of single and 14-day pre-ischemic KGKR treatment on neuronal damage in the same repeated cerebral ischemia model. Additionally, to determine the mechanisms of neuroprotection by KGKR at glutamatergic neurons, we examined the effects of KGKR on glutamate release induced by repeated cerebral ischemia in vivo, and on cell damage induced by both glutamate and kainate in primary cultured hippocampal neurons in vitro. The 14-day pre-ischemic KGKR (300 mg/kg, oral administration (p.o.)) treatment reduced neuronal damage and astrocyte expression induced by repeated cerebral ischemia. No effect was observed after single pre-ischemic KGKR treatment. Both single and 14-day KGKR treatment decreased glutamate release in the hippocampal CA1 region in intact rats; however, neither pre-ischemic KGKR treatment altered glutamate release during cerebral ischemia. In vitro, KGKR (100-1000 microg/mL) dose-dependently suppressed hippocampal neuronal damage induced by both glutamate (100 microM) and kainate (1 mM). These data suggest neuroprotection with KGKR requires continuous pre-ischemic treatment, and that the mechanisms of protection may be involved in inhibiting the glutamatergic receptors of the post-synaptic neurons.

The cannabinoid 1-receptor silent antagonist O-2050 attenuates preference for high-fat diet and activated astrocytes in mice.

Endocannabinoids have been shown to activate reward-related feeding and to promote astrocytic differentiation. We investigated whether high-fat diet (HFD) intake produced a preference for HFD via an endocannabinoid-dependent mechanism. In the conditioned place preference test, the 2-week HFD-intake group showed preference for HFD and had increased expression of a marker for reactive astrocytes, glial fibrillary acid protein (GFAP), in the hypothalamus. The cannabinoid CB(1)-receptor antagonist O-2050 reduced the preference for HFD and expression of GFAP in the hypothalamus. These results suggested that HFD intake led to the development of a preference for HFD via astrocytic CB(1) receptors in the hypothalamus.

Neuroprotective effects of Kangen-karyu on spatial memory impairment in an 8-arm radial maze and neuronal death in the hippocampal CA1 region induced by repeated cerebral ischemia in rats.

In the present study, we investigated the neuroprotective effects of Kangen-karyu (KGK) in a repeated cerebral ischemia model (2 x 10 min, 1-h interval). A 21-day pre- and post-ischemic treatment with KGK (10 - 300 mg/kg) and aspirin (5 mg/kg) improved the spatial memory impairment and neuronal death in the hippocampal CA1 region induced by repeated cerebral ischemia. However, a 7-day post-ischemic treatment with KGK did not attenuate the spatial memory impairment and neuronal death in this model. To determine the mechanism of action of KGK, we investigated the effects of a 14-day pre-ischemic treatment with KGK on cerebral blood flow in the hippocampal area of the repeated cerebral ischemia model using laser Doppler flowmetry. The 14-day pre-ischemic treatment with KGK increased the cerebral blood flow during reperfusion. These results suggest that a 21-day pre- and post-ischemic treatment with KGK can protect against brain damage caused by cerebral ischemia by increasing the cerebral blood flow in the hippocampal area.

Cannabidiol prevents a post-ischemic injury progressively induced by cerebral ischemia via a high-mobility group box1-inhibiting mechanism.

We examined the cerebroprotective mechanism of cannabidiol, the non-psychoactive component of marijuana, against infarction in a 4-h mouse middle cerebral artery (MCA) occlusion model. Cannabidiol was intraperitoneally administrated immediately before and 3h after cerebral ischemia. Infarct size and myeloperoxidase (MPO) activity, a marker of neutrophil, monocyte/macropharge, were measured at 24h after cerebral ischemia. Activated microglia and astrocytes were evaluated by immunostaining. Moreover, high-mobility group box1 (HMGB1) was also evaluated at 1 and 3 days after MCA occlusion. In addition, neurological score and motor coordination on the rota-rod test were assessed at 1 and 3 days after cerebral ischemia. Cannabidiol significantly prevented infarction and MPO activity at 20h after reperfusion. These effects of cannabidiol were not inhibited by either SR141716 or AM630. Cannabidiol inhibited the MPO-positive cells expressing HMGB1 and also decreased the expression level of HMGB1 in plasma. In addition, cannabidiol decreased the number of Iba1- and GFAP-positive cells at 3 days after cerebral ischemia. Moreover, cannabidiol improved neurological score and motor coordination on the rota-rod test. Our results suggest that cannabidiol inhibits monocyte/macropharge expressing HMGB1 followed by preventing glial activation and neurological impairment induced by cerebral ischemia. Cannabidiol will open new therapeutic possibilities for post-ischemic injury via HMGB1-inhibiting mechanism.

Delayed treatment with cannabidiol has a cerebroprotective action via a cannabinoid receptor-independent myeloperoxidase-inhibiting mechanism.

We examined the neuroprotective mechanism of cannabidiol, non-psychoactive component of marijuana, on the infarction in a 4 h mouse middle cerebral artery (MCA) occlusion model in comparison with Delta(9)-tetrahydrocannabinol (Delta(9)-THC). Release of glutamate in the cortex was measured at 2 h after MCA occlusion. Myeloperoxidase (MPO) and cerebral blood flow were measured at 1 h after reperfusion. In addition, infarct size and MPO were determined at 24 and 72 h after MCA occlusion. The neuroprotective effect of cannabidiol was not inhibited by either SR141716 or AM630. Both pre- and post-ischemic treatment with cannabidiol resulted in potent and long-lasting neuroprotection, whereas only pre-ischemic treatment with Delta(9)-THC reduced the infarction. Unlike Delta(9)-THC, cannabidiol did not affect the excess release of glutamate in the cortex after occlusion. Cannabidiol suppressed the decrease in cerebral blood flow by the failure of cerebral microcirculation after reperfusion and inhibited MPO activity in neutrophils. Furthermore, the number of MPO-immunopositive cells was reduced in the ipsilateral hemisphere in cannabidiol-treated group. Cannabidiol provides potent and long-lasting neuroprotection through an anti-inflammatory CB(1) receptor-independent mechanism, suggesting that cannabidiol will have a palliative action and open new therapeutic possibilities for treating cerebrovascular disorders.

Post-ischemic treatment with toki-shakuyaku-san (tang-gui-shao-yao-san) prevents the impairment of spatial memory induced by repeated cerebral ischemia in rats.

Previously we have reported that Toki-shakuyaku-san (TSS) ameliorated the impairment of spatial memory induced by single cerebral ischemia (1 x 10 minutes) and scopolamine, a muscarinic receptor antagonist. In this experiment, we studied the effect of TSS on repeated cerebral ischemia (2 x 10 minutes, 1-hour interval) induced impairment of spatial memory and neuronal injury in rats. The 8-day post-ischemic treatment with TSS (30-300 mg/kg) was administered p.o. once per day. TSS dose-dependently prevented the impairment of spatial memory, neuronal death and TUNEL positive cells induced by repeated cerebral ischemia. In order to determine the mechanism of TSS, we also studied the effect of TSS on GluR2 mRNA, one of the glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) receptor subunits. Repeated cerebral ischemia significantly decreased GluR2 flop mRNA at 1 and 3 days after the occlusion. TSS (300 mg/kg) significantly suppressed the decrease in GluR2 flop at 3 days after repeated cerebral ischemia. These results suggested that the TSS has neuroprotective action which may be indirectly mediated by the AMPA receptor, and TSS may be beneficial for the treatment of cerebrovascular dementia.

Protective effect of buckwheat polyphenols against long-lasting impairment of spatial memory associated with hippocampal neuronal damage in rats subjected to repeated cerebral ischemia.

In the present experiment, we studied the action of buckwheat polyphenol (BWP, from Fagopyrum esculentum MOENCH) in a repeated cerebral ischemia model, which induced a strong and long-lasting impairment of spatial memory in 8-arm radial maze with hippocampal CA1 cell death in rats. BWP (600 mg/kg, continuous 21-day p.o.) significantly ameliorated not only the impairment of spatial memory in the 8-arm radial maze, but also necrosis and TUNEL-positive cells in the hippocampal CA1 area subjected to repeated cerebral ischemia (10 min x 2 times occlusion, 1-h interval) in rats. In order to investigate the mechanism of BWP protective action, we measured the release of glutamate and NO(x)(-) (NO(2)(-) + NO(3)(-)) production induced by repeated cerebral ischemia in the rat dorsal hippocampus using microdialysis. A 14-day BWP treatment significantly inhibited the excess release of glutamate after the second occlusion. In addition, the BWP remarkably suppressed a delayed increase in NO(x)(-) (NO(2)(-) + NO(3)(-)) induced by repeated cerebral ischemia in the dorsal hippocampus as determined in vivo by microdialysis. However, the 14-day treatment did not affect hippocampal blood flow in either intact rats or rats subjected to repeated ischemia measured by lasser Doppler flowmeter. These results suggested that BWP might ameliorate spatial memory impairment by inhibiting glutamate release and the delayed generation of NO(x)(-) in rats subjected to repeated cerebral ischemia.