Hirozo Goto

Astaxanthin, a carotenoid with potential in human health and nutrition.

Astaxanthin (1), a red-orange carotenoid pigment, is a powerful biological antioxidant that occurs naturally in a wide variety of living organisms. The potent antioxidant property of 1 has been implicated in its various biological activities demonstrated in both experimental animals and clinical studies. Compound 1 has considerable potential and promising applications in human health and nutrition. In this review, the recent scientific literature (from 2002 to 2005) is covered on the most significant activities of 1, including its antioxidative and anti-inflammatory properties, its effects on cancer, diabetes, the immune system, and ocular health, and other related aspects. We also discuss the green microalga Haematococcus pluvialis, the richest source of natural 1, and its utilization in the promotion of human health, including the antihypertensive and neuroprotective potentials of 1, emphasizing our experimental data on the effects of dietary astaxanthin on blood pressure, stroke, and vascular dementia in animal models, is described.

Evaluation of the Protective Effects of Alkaloids Isolated from the Hooks and Stems of Uncaria sinensis on Glutamate-induced Neuronal Death in Cultured Cerebellar Granule Cells from Rats

We have previously shown that an aqueous extract of the hooks and stems of Uncaria sinensis (Oliv.) Havil., Uncariae Uncus Cum Ramulusis, protects against glutamate‐induced neuronal death in cultured cerebellar granule cells by inhibition of Ca2+ influx. Because it is not known which components of Uncaria sinensis are active, in this study we have evaluated, by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide (MTT) staining, the neuroprotective effects of the oxyindole alkaloids corynoxeine, rhynchophylline, isorhynchophylline and isocorynoxeine, and the indole alkaloids geissoschizine methyl ether, hirsuteine and hirsutine, isolated from the hooks and stems of Uncaria sinensis, on glutamate‐induced cell death. We also investigated the inhibitory effects of the compounds on 45Ca2+ influx in cultured rat cerebellar granule cells.

Protective Effect of Phenolic Compounds Isolated from the Hooks and Stems of Uncaria sinensis on Glutamate-Induced Neuronal Death

We isolated the phenolic compounds epicatechin, catechin, procyanidin B-1, procyanidin B-2, hyperin and caffeic acid from the hooks and stems of Uncaria sinensis (HSUS), and studied their protective effects against glutamate-induced neuronal death in cultured rat cerebellar granule cells. Cell viability evaluated by MTT assay was significantly increased by application of epicatechin (100-300 microM), catechin (300 microM), procyanidin B-1 (30-300 microM) and procyanidin B-2 (100-300 microM) compared with exposure to glutamate only. 45Ca2+ influx into cells induced by glutamate was also significantly inhibited by administration ofepicatechin (300 microM), catechin (300 microM), procyanidin B-1 (100-300 microM) and procyanidin B-2 (100-300 microM). These results suggest that epicatechin, catechin, procyanidin B-1 and procyanidin B-2 are the active components of HSUS that protect against glutamate-induced neuronal death in cultured cerebellar granule cells by inhibition of Ca2+ influx.

A Proteomic Approach for the Diagnosis of ‘Oketsu’ (blood stasis), a Pathophysiologic Concept of Japanese Traditional (Kampo) Medicine

‘Oketsu’ is a pathophysiologic concept in Japanese traditional (Kampo) medicine, primarily denoting blood stasis/stagnant syndrome. Here we have explored plasma protein biomarkers and/or diagnostic algorithms for ‘Oketsu’. Sixteen rheumatoid arthritis (RA) patients were treated with keishibukuryogan (KBG), a representative Kampo medicine for improving ‘Oketsu’. Plasma samples were diagnosed as either having an ‘Oketsu’ (n = 19) or ‘non-Oketsu’ (n = 29) state according to Terasawas ‘Oketsu’ scoring system. Protein profiles were obtained by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and hierarchical clustering and decision tree analyses were performed. KBG treatment for 4 or 12 weeks decreased the ‘Oketsu’ scores significantly. SELDI protein profiles gave 266 protein peaks, whose expression was significantly different between the ‘Oketsu’ and ‘non-Oketsu’ states. Hierarchical clustering gave three major clusters (I, II, III). The majority (68.4%) of ‘Oketsu’ samples were clustered into one cluster as the principal component of cluster I. The remaining ‘Oketsu’ profiles constituted a minor component of cluster II and were all derived from patients cured of the ‘Oketsu’ state at 12 weeks. Construction of the decision tree addressed the possibility of developing a diagnostic algorithm for ‘Oketsu’. A reduction in measurement/pre-processing conditions (from 55 to 16) gave a similar outcome in the clustering and decision tree analyses. The present study suggests that the pathophysiologic concept of Kampo medicine ‘Oketsu’ has a physical basis in terms of the profile of blood proteins. It may be possible to establish a set of objective criteria for diagnosing ‘Oketsu’ using a combination of proteomic and bioinformatics-based classification methods.

Effects of Keishi-bukuryo-gan on vascular function and hemorheological factors in spontaneously diabetic (WBN/kob) rats

Keishi-bukuryo-gan (Gui-zhi-fu-ling-wan) is a formula used for the improvement of blood circulation. Recently it has often also been used for arteriosclerosis. One of the mechanisms involved is thought to be the improvement of endothelial dysfunction, but the details are still unclear. In this study, the effect of Keishi-bukuryo-gan on vascular function and hemorheological factors in spontaneously diabetic (WBN/kob) rats was studied. Rats were given Keishi-bukuryo-gan in chow for 30 weeks. Body weight, blood glucose, endothelium-dependent/-independent relaxation, vasocontraction by free radical-induced and contractive prostanoids, triglyceride, advanced glycation endproduct, lipid peroxides, serum NO2-/NO3- and blood viscosity were measured. The results indicated that Keishi-bukuryo-gan caused a decrease in endothelium-dependent relaxation by acetylcholine to become significantly increased, and vasocontraction induced by free radicals and contractive prostanoids was significantly decreased. Furthermore, serum NO2-/NO3- and blood viscosity were significantly decreased. From these results, it was supposed that Keishi-bukuryo-gan exerted a protective effect on the endothelium. The WBN/kob rat is a useful study model for the complications of human diabetes, and Keishi-bukuryo-gan showed a protective effect against vascular injury in the susceptible rat.

Keishi-bukuryo-gan prevents the progression of atherosclerosis in cholesterol-fed rabbit

In this study, we examined whether in vivo keishi‐bukuryo‐gan (a Kampo formulation) could prevent the progression of atherosclerosis in cholesterol‐fed rabbits, an animal model for hypercholesterolaemia. Sixteen male Japanese white rabbits (2 kg body weight) were divided into two groups. Group A (n = 8) was fed standard rabbit chow containing 1% cholesterol for 8 weeks. Group B (n = 8) was fed standard rabbit chow containing 1% cholesterol and 1% keishi‐bukuryo‐gan for 8 weeks. At the end of the experiment, average plasma concentrations of total‐cholesterol and IDL‐cholesterol were 2055.9 ± 201.8 mg/dL and 408.1 ± 62.6 mg/dL in group A and 1950.5 ± 126.3 mg/dL and 407.6 ± 56.6 mg/dL in group B, respectively. The percentage of the surface area of the total thoracic aorta with visible plaque was significantly reduced by keishi‐bukuryo‐gan administration; group A was 33.2% ± 5.3% and group B was 14.3% ± 2.9%. β ‐very low density lipoprotein (VLDL) and low density lipoprotein (LDL) isolated from cholesterol fed rabbits treated with keishi‐bukuryo‐gan (group B) were shown to be highly resistant to oxidative modification by cupric ion. Sera isolated from rabbits administered keishi‐bukuryo‐gan had reduced lipid peroxide formation compared with those from rabbits without keishi‐bukuryo‐gan. Thus, keishi‐bukuryo‐gan prevents the progression of atherosclerosis in cholesterol‐fed rabbits in vivo by limiting oxidative LDL modification. Copyright

Enteric Excretion of Baicalein, a Flavone of Scutellariae Radix, via Glucuronidation in Rat: Involvement of Multidrug Resistance-Associated Protein 2

AbstractPurpose. Baicalin (BG) and its aglycone, baicalein (B), are strong antioxidants and have various pharmacological actions. The purpose of this study was to evaluate efflux of BG from rat intestinal mucosal cell following glucuronidation of B absorbed after oral administration of B. Methods. The absorption and excretion of BG and B were evaluated in rats using the in situ jejunal loop technique and in vitro jejunal everted sac experiments. BG and B levels were determined by high-performance liquid chromatography with electro-chemical detection to ensure selectivity and high sensitivity. Results. A large amount (30.4% recovery) of BG, but no B, was detected in the intestinal lumens of germ-free rats 4 h after oral administration of B (12.1 mg/kg), in comparison with a substantial recovery (55.1%) of unabsorbed BG 4 h after its administration. During the in situ rat jejunal loop absorption experiment, B disappeared rapidly, and 8% of the lost B was excreted into the loop as BG 20 min after infusing 0.1 mM B. In an in vitro absorption experiment using everted rat jejunal sac, BG also appeared outside the sac, accompanied by the disappearance of B from the outer (mucosal) side. However, very little of B was transferred to the inner (serosal) side of the sac, and only a trace of BG was detected inside the sac. Thus, in both the loop and the everted sac systems, the efflux of BG from the mucosal surface was saturated with the concentration of B added. Moreover, the efflux rate of BG in the everted jejunal sac from Eisai hyperbilirubinemic rat (EHBR) was significantly lower by 56.4% than that from Sprague-Dawley rat. Conclusions. These results indicate that, in rat, a large proportion of any B absorbed is retained, transformed into BG within the intestinal mucosal cells, and coordinately excreted through multidrug resis- tance-associated protein 2 (MRP2) into the intestinal lumen.

Vasodilator effect of extract prepared from Uncariae ramulus on isolated rat aorta.

Uncariae ramulus et Uncus (URE) has a vasodilator effect. Its mechanism consists of not only endothelium-independent relaxation with Ca2+ channel blocking effect but also endothelium-dependent relaxation with nitric oxide. The active components are alkaloids and tannin contained in Uncariae ramulus et Uncus. They also show a superoxide dismutase-like effect and suppressed vasocontraction induced by xanthine and xanthine oxidase. These mechanisms may also influence vasodilatation by Uncariae ramulus et Uncus in vivo.

Keishibukuryogan (Gui-Zhi-Fu-Ling-Wan), a Kampo Formula, Decreases Disease Activity and Soluble Vascular Adhesion Molecule-1 in Patients with Rheumatoid Arthritis

An increasing death rate due to cardiovascular disease in patients with rheumatoid arthritis (RA) has been reported. Keishibukuryogan (KBG) is a traditional Chinese/Japanese (Kampo) formula that has been administered to patients with blood stagnation, e.g. thrombotic disease and atherosclerosis. The objective of this study was to evaluate the efficacy of KBG on disease activity and endothelial dysfunction in RA patients. Sixteen RA patients were enrolled and administered KBG (12 g per day) for 12 weeks in addition to continuing other drugs. The disease activity of RA was assessed by modified disease activity scores for 28 joints (DAS28). Plasma levels of adhesion molecules, soluble E-selectin (sE-selectin), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were evaluated. C-reactive protein (CRP), inflammatory cytokines (IL-1β, IL-6 and TNF-α) and lipid peroxide (LPO) were also evaluated. Fourteen patients completed the study. The disease activity of RA, tender joint count, swollen joint count and DAS28 decreased significantly. Among adhesion molecules, only sVCAM-1 decreased significantly. LPO also decreased significantly, whereas CRP and inflammatory cytokines remained unchanged. These results suggest that KBG has insufficient anti-inflammatory or immunomodulating effect but does have a beneficial effect on articular symptoms and a protective effect against endothelial dysfunction in RA patients.

Extract prepared from the bark of Cinnamomum cassia Blume prevents glutamate-induced neuronal death in cultured cerebellar granule cells

We studied the protective effect of a water extract from the bark of Cinnamomum cassia Blume on glutamate‐induced neuronal death by MTT assay and its action on 45Ca2+ influx using cultured rat cerebellar granule cells. In a dose‐dependent manner, this extract (10−5–10−4 g/mL) significantly protected against glutamate‐induced cell death and also inhibited glutamate‐induced 45Ca2+ influx. These results suggest that the bark of Cinnamomum cassia has a protective effect on glutamate‐induced neuronal death through the inhibition of Ca2+ influx. Copyright