Search

Japanese mint (Mentha arvensis var. piperascens Malinv. ex Holmes), ‘hokuto,’ is the highest-yield cultivar and contains a large amount of l-menthol in its essential oil. We focused on the dementho...

Previous studies reported the activity of fucoidans and polyphenols (phlorotannins) extracted from brown algae against enveloped viruses. The aim of this study was to investigate the effects of brown macroalgae on the non-enveloped norovirus. Aqueous acetic acid macromolecular (>3 kDa) extracts (AAEs) were obtained from ten samples of eight brown macroalgal species. Saccharides and sulphate composition, weight-averaged molecular weight, and total phenolic content (TPC) of the AAEs were measured to estimate their fucoidan and polyphenol content. Murine RAW264.7 macrophage cells and the human norovirus surrogate murine norovirus-1 (MNV-1) were used for the anti-norovirus assay. One hour of direct exposure to TPC-rich AAEs from Sargassum horneri (Sh), Eisenia bicyclis (Eb), Cladosiphon okamuranus (Co), and Undaria pinnatifida inactivated MNV-1. In contrast, pre-treatment of RAW264.7 cells for 20 h with AAEs from another U. pinnatifida sample, Analipus japonicus, and Co protected RAW264.7 cells against MNV-1 infection. The AAEs from Co contained high TPC and sulphated fucans (fucoidans) might be the most promising anti-norovirus agents as they directly inactivated MNV-1 and protected RAW264.7 cells from it. The AAEs of phlorotannin-rich Sh and Eb are also potentially effective at direct inactivating MNV-1.

The sedative effects of volatile components in the essential oil of Artemisia montana ("Yomogi") were investigated and measured using gas chromatography-mass spectrometry (GC-MS). Major components identified included 1,8-cineol, camphor, borneol, α-piperitone, and caryophyllene oxide. Among them, 1,8-cineol exhibited the highest flavor dilution (FD) value in an aroma extract dilution analysis (AEDA), followed by borneol, o-cymene, β-thujone, and bornyl acetate. The sedative effects of yomogi oil aroma were evaluated by sensory testing, analysis of salivary α-amylase activity, and measurement of relative fluctuation of oxygenated hemoglobin concentration in the brain using near-infrared spectroscopy (NIRS). All results indicated the stress-reducing effects of the essential oil following nasal exposure, and according to the NIRS analysis, 1,8-cineol is likely responsible for the sedative effects of yomogi oil.

C-Glycosidic ellagitannins grandinin (1), vescalagin (2), castalagin (3), methylvescalagin (4), stachyurin (5), and casuarinin (6) were isolated from the 50% acetone extract of camu-camu (Myrciaria dubia) seeds and peel. These tannins exhibited antioxidant activities measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, and the oxygen radical absorbance capacity (ORAC) assay. In the DPPH and ABTS assays, stachyurin exhibited the strongest antioxidant activity among the tannins, and the activities were stronger for tannins containing two hexahydroxydiphenoyl (HHDP) groups and a galloyl group than for tannins containing a nonahydroxyterphenoyl group and a HHDP group. The activity of vescalagin was stronger than that of castalagin, and a similar relationship was observed for stachyurin and casuarinin. Thus, the antioxidant activities of these tannins may depend on the conformation of the hydroxyl group at C-1 of the open ring d -glucose. However, in the ORAC assay, casuarinin exhibited the strongest activity, and the respective activities could not be explained by the structural rigidity or conformation of the C-1 hydroxyl group. The seeds and peel of camu-camu, waste products of juice production, were found to contain C-glycosidic ellagitannins with potent antioxidant activities, and thus, they could be a useful resource for functional foods and food additives.

C型肝炎ウイルス（HCV）感染者は、世界に１億人以上いるとされている。先進国では先端的な医薬品の開発で、HCVを病原とする慢性及び急性C型肝炎の治癒率は飛躍的に高まった。一方、世界には経済的に、また医療体制の問題から、それら先端医薬品を手に入れ難い地域も多い。我々は安価で、また手に入れやすいC型肝炎治療薬を開発するために、各地の伝統薬物（生薬）に着目した。特にタンニンを多く含んだ13生薬を選び、メタノールエキスを作成した。HCVの感染に必須であるHCVタンパク質分解酵素を、大腸菌で生成し、この組み換え酵素に対する阻害効果をスクリーニングした。13のエキスのうち６のエキスの100 μg/mlに、90％以上のHCVタンパク質分解酵素阻害効果を認めた。ポリフェノール含量の高いエキス（800-1500 μgGAE/ml）が阻害効果も高い傾向であったが、阿仙薬エキスはポリフェノール含量が高い（1300 μgGAE/ml以上）にも係らず、ほとんど阻害効果がなかった。一方柿蔕エキスは、ポリフェノール含量は比較的低かったが（400 μgGAE/ml以下）、高い阻害活性が認められ、ポリフェノールの種類によっても、阻害活性が異なることが示唆された。今後柿蔕の活性成分について、さらに詳しく研究する。, Aiming at finding novel hepatits C virus (HCV) drugs having easier access and requiring less economical burden, we studied on crude drugs for anti HCV protease activity. Thirteen crude drugs which are known rich in tannins were selected, since we had found peel and seeds of a tropical fruit in Peru, Camu camu, and their tannic ingredients were effectively inhibited the recombinant HCV protease. Methanolic extracts of the crude drugs were tested for inhibitory activity on the enzyme reaction, and 6 of them at a concentration of 100 μg/ml inhibited the reaction more than 90 %. Five of these effective extracts contained as much as 800-1500 μgGAE/ml phenolics, but the extract of kaki calyx (KC) contained less than 400 μgGAE/ml. On the other hand, that of gambir (Ga), which contained more than 1300 μgGAE/ml phenolics, did not effectively inhibit the reaction. We now focus on the effective ingredients contained in the extract of KC.

Brown algal polysaccharides such as alginate, polymers of uronic acids, and laminaran, beta-1,3 and 1,6-glucan, can be fermented by human intestinal microbiota. To evaluate the effects of these polysaccharides on infections caused by food poisoning pathogens, we investigated the adhesion and invasion of pathogens (Salmonella Typhimurium, Listeria monocytogenes and Vibrio parahaemolyticus) in human enterocyte-like HT-29-Luc cells and in infections caused in BALB/c mice. Both sodium Na-alginate and laminaran (0.1% each) inhibited the adhesion of the pathogens to HT-29-Luc cells by approximately 70-90%. The invasion of S. Typhimurium was also inhibited by approximately 70 and 80% by Na-alginate and laminaran, respectively. We observed that incubation with Na-alginate for 18 h increased the transepithelial electrical resistance of HT-29-Luc monolayer cells. Four days after inoculation with 7 log CFU/mouse of S. Typhimurium, the faecal pathogen count in mice that were not fed polysaccharides (control mice) was about 6.5 log CFU/g while the count in mice that were fed Na-alginate had decreased to 5.0 log CFU/g. The liver pathogen count, which was 4.1 log CFU/g in the control mice, was also decreased in mice that were fed Na-alginate. In contrast, the mice that were fed laminaran exhibited a more severe infection than that exhibited by control mice.

Objective The objective of this study is to elucidate the effect of anagliptin on glucose/lipid metabolism and renoprotection in patients with type 2 diabetic nephropathy. Methods Twenty-five patients with type 2 diabetic nephropathy received anagliptin 200 mg/day for 24 weeks, and 20 patients who were switched to anagliptin from other dipeptidyl peptidase-4 (DPP-4) inhibitors were analyzed regarding primary and secondary endpoints. The primary endpoint was change in hemoglobin A1c (HbA1c) during treatment with anagliptin. Additionally, we evaluated changes in lipid data (low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and triglyceride), blood pressure (BP), urinary albumin to creatinine ratio (UACR), liver-type fatty acid-binding protein to creatinine ratio (ULFABP) and renal function (estimated glomerular filtration rate and serum cystatin C) as secondary endpoints. Results After switching to anagliptin from other DPP-4 inhibitors, the levels of HbA1c in the 20 participants showed no significant change, 7.5%±1.2% at 24 weeks compared with 7.3%±0.9% at baseline. The levels of the log10-transformed UACR were significantly reduced from 1.95±0.51 mg/g creatinine (Cr) at baseline to 1.76±0.53 mg/g Cr at 24 weeks after anagliptin treatment (p

Various antimicrobial constituents of camu-camu fruit were isolated. Acylphloroglucinol (compound 1) and rhodomyrtone (compound 2) were isolated from the peel of camu-camu (Myrciaria dubia) fruit, while two other acylphloroglucinols (compounds 3 and 4) were obtained from camu-camu seeds. The structures of the isolated compounds were characterized by spectrophotometric methods. Compounds 1 and 4 were confirmed to be new acylphloroglucinols with different substituents at the C7 or C9 position of 2, and were named myrciarone A and B, respectively. Compound 3 was determined to be isomyrtucommulone B. This is the first report of the isolation of 3 from a natural resource. The antimicrobial activities of compounds 1, 3, and 4 were similar to those of 2, and the minimum inhibitory concentrations were either similar to or lower than that of kanamycin. These results suggest that the peel and seeds of camu-camu fruit could be utilized for therapeutic applications.

The sedative effects of volatile components in the essential oil of Artemisia montana ("Yomogi") were investigated and measured using gas chromatography-mass spectrometry (GC-MS). Major components identified included 1,8-cineol, camphor, borneol, α-piperitone, and caryophyllene oxide. Among them, 1,8-cineol exhibited the highest flavor dilution (FD) value in an aroma extract dilution analysis (AEDA), followed by borneol, o-cymene, β-thujone, and bornyl acetate. The sedative effects of yomogi oil aroma were evaluated by sensory testing, analysis of salivary α-amylase activity, and measurement of relative fluctuation of oxygenated hemoglobin concentration in the brain using near-infrared spectroscopy (NIRS). All results indicated the stress-reducing effects of the essential oil following nasal exposure, and according to the NIRS analysis, 1,8-cineol is likely responsible for the sedative effects of yomogi oil.

We previously reported that glucagon-like peptide-1 (GLP-1) appearance in the portal vein facilitates hepatic vagal afferent activity, and this further augments reflexively the pancreatic vagal efferents in anesthetized rats, suggesting a neuroincretin effect of GLP-1. To determine whether the GLP-1-induced vagal pathways lead to a neuronal-mediated component (NMC) of insulin secretion, we infused GLP-1 at a physiological or pharmacological dose (1 or 3 pmol·kg−1·min−1, respectively) into the portal vein in conscious rats with selective hepatic vagotomy (Vagox) or sham operation (Sham). The experiments consisted of two sequential 10-min intraportal infusions (P1 and P2): glucose at a physiological rate (56 μmol·kg−1·min−1) in P1 and the glucose plus GLP-1 or vehicle in P2. Under arterial isoglycemia across the groups, the physiological GLP-1 infusion in Sham augmented promptly and markedly arterial insulin levels, approximately twofold the levels in glucose alone infusion ( P < 0.005), and insulin levels in Vagox diminished apparently ( P < 0.05). Almost 60% of the GLP-1-induced insulin secretion (AUC) in Sham met the NMC, i.e., difference between insulin secretion in Sham and Vagox, (AUC 976 ± 65 vs. 393 ± 94 pmol·min/l, respectively, P < 0.005). Intraportal pharmacological GLP-1 infusion further augmented insulin secretion in both groups, but the NMC remained in 46% (NS; Sham vs. Vagox). In contrast, “isoglycemic” intravenous GLP-1 infusion (3 pmol·kg−1·min−1) evoked an equal insulin secretion in both groups. Thus, the present results indicate that GLP-1 appearing in the portal vein evokes a powerful neuronal-mediated insulinotropic effect, suggesting the neuroincretin effect.

An impaired ability to sense and respond to drug-induced hypoglycemia is a common and serious complication in diabetic patients. The hypothalamic-pituitary-adrenal (HPA) axis activity plays a critical role in the counterregulatory response to hypoglycemia. We herein report a case that experienced restoration of a blunted HPA axis by avoiding hypoglycemia with the use of the DPP-4 inhibitor sitagliptin.

Electroacupuncture (EA) has been observed to reduce insulin resistance in obesity and diabetes. However, the biochemical mechanism underlying this effect remains unclear. This study investigated the effects of low-frequency EA on metabolic action in genetically obese and type 2 diabetic db/db mice. Nine-week-old db/m and db/db mice were randomly divided into four groups, namely, db/m, db/m + EA, db/db, and db/db + EA. db/m + EA and db/db + EA mice received 3-Hz electroacupuncture five times weekly for eight consecutive weeks. In db/db mice, EA tempered the increase in fasting blood glucose, food intake, and body mass and maintained insulin levels. In EA-treated db/db mice, improved insulin sensitivity was established through intraperitoneal insulin tolerance test. EA was likewise observed to decrease free fatty acid levels in db/db mice; it increased protein expression in skeletal muscle Sirtuin 1 (SIRT1) and induced gene expression of peroxisome proliferator-activated receptor coactivator (PGC-), nuclear respiratory factor 1 (NRF1), and acyl-CoA oxidase (ACOX). These results indicated that EA offers a beneficial effect on insulin resistance in obese and diabetic db/db mice, at least partly, via stimulation of SIRT1/PGC-, thus resulting in improved insulin signal.

Mei-gui hua has been used as a crude drug in traditional medicine and as herbal tea in China. The scientific name of Mei-gui is Rosa rugosa thunb. However, the morphological characteristics and botanical ecology of Mei-gui were different from those of R. rugosa. Since the botanical origins of Mei-gui cultivated in China have not yet been clarified, we compared Mei-gui and R. rugosa in terms of their morphological characteristics, phylogenetic analysis, and phytochemical studies. Our research suggested that Mei-gui cultivated around Tarim Basin in Xinjiang Province showed homology to Rosa gallica, while those cultivated in the northeastern parts of China are considered to be hybrids of R. rugosa.

The petals of Rosa rugosa and allied plants for medicinal use contain abundant hydrolysable tannins, and they show remarkable biological activities. The activities are dependent on the structures of the hydrolysable tannins, so their contents and compositions are essential for evaluation of medicinal potency. Therefore, we optimized the simultaneous quantitative determination of the hydrolysable tannins using ultra-performance liquid chromatography. A column of ethylene bridged hybrid (BEH) phenyl (C(6) alkyl phenyl group as solid-phase modification) was shown to be most effective for the separation of hydrolysable tannins isolated from R. rugosa and related compounds when the column temperature was kept under 25 degrees C. The efficacy of the BEH phenyl column might be due to the interaction between solid phase and phenolic ester groups of hydrolysable tannins such as galloyl, hexahydroxydiphenoyl and valoneoyl groups. The relation between the retention times on the BEH phenyl column and the column temperature was demonstrated to depend on the structural characteristics of hydrolysable tannins.

石膏析出後の酸性硫酸塩土と，土質試験の一斉試験などでしばしば用いられる深草土の両者に対して，消石灰を異なる混合率で混ぜ合わせ，pH試験と一軸圧縮試験を各養生日数で実施した．これらの実験結果から，両安定処理土のpHおよび強度特性（特に強度発現速度）を比較し，その差異を明らかにした上で，石灰混合による酸性硫酸塩土の安定処理効果について詳細に検討した．また，実験に用いた供試体を走査型電子顕微鏡（SEM）で可視化し，土と石灰・石膏の水和反応によって形成されたエトリンガイトと土の強度特性が密接に関係していることを理解した．

バイオマス資源として期待されるクマイザサの天然色素, イソオリエンチンの含量について生育環境との関連を検討した。ササ葉のイソオリエンチン含量と, 土壌の金属元素 (Na, Mg, Si, P, Ca, Zn, B), 窒素化合物量との間の関係は, 下層土壌 (深さ20-30cm) のリン含量と負の相関を示したものの, ほかの土壌成分との間に相関はみられなかった。イソオリエンチン含量には季節変動がみられた。また, チシマザサやミヤコザサに比べ, クマイザサのイソオリエンチン含量は低い値を示した。相対照度0%のササ葉ではイソオリエンチン含量は, 相対照度35%に比べて1/10と低い値である一方, 相対照度0-35%に2週間置いた葉では6.6倍に増加した。イソオリエンチン含量は照度と関連することが示唆された。

Two fucoidans have been isolated from the holdfast of cultivated Laminaira japonica. One (L-fucoidan) is rich in fucose and sulfate; the other (GA-fucoidan) is rich in uronate. L-fucoidan was found in the fronds of L. japonica (cultivated and wild), L. angustata, and Kjellmaniella crassifolia whereas GA-fucoidan was not detected in these fronds and may be a fucoidan specific to the holdfast. These two fucoidans were proved to have anti-tumor activity against Adenocarcinoma 755-transplanted mice by i.p. and p.o. administration.

Alginic acid is a liner hetero-polysaccharide consists of d-mannuronic acid (M) and l-guluronic acid (G). The alginate, whose molecular weight and the mannuronic acid/guluronic acid (M/G) ratio are adjusted, are used extensively in food, pharmaceutical industries, and so on. In this study, we developed the rapid decomposition of sodium alginate (Alg-Na) using subcritical and supercritical water (abbreviated as subH2O and scH2O, respectively) microreaction systems, and investigated the controllability of the molecular weight and the M/G ratio by varying temperature and pressure. In scH2O, glucosidic linkages and hexose rings of Alg-Na were completely cleaved by hydrolysis to form unknown complex mixture. Whereas in the subH2O (523 K, 25 MPa), G−M and M−G linkages were hydrolyzed selectively. As the result, we successfully obtained the almost-pure guluronic acid homo-polymer and the mannuronic acid-rich water-soluble hetero-polymer selectively.

The inhibitory effects of laminaran and low molecular weight sodium alginate (MW = 49,000) against formation of ammonia, indole compounds and phenol compounds, putrefactive and harmful compounds, induced by human fecal microflora, were examined in vitro. Laminaran was fermented to acetate, propionate, n -butyrate and lactate. The alginate was fermented to acetate and propionate. Both of these polysaccharides inhibited formation of the putrefactive compounds. In the case of rats fed diet containing 2% (w/w) laminaran or low molecular alginate, the fermentation pattern agreed with that of the in vitro experiment. Laminaran suppressed indole, p -cresole and sulfide, significantly. These putrefactive compounds, in rats fed low molecular alginate, also tended to be lower. These results suggest that the fermentation of laminaran by intestinal bacteria suppresses the putative risk markers for colon cancer.

MCl gel eluted with the solvent system H 2 O–MeOH–acetone, and five fractions were obtained. The fractions obtained by stepwise gradient with H 2 O–MeOH contained flavones with different degrees of galloylation. Fractions 1 and 2 eluted with 90 and 80% H 2 O, respectively, contain two galloylated flavonoids (compounds 1 and 2, respectively) and were isolated by repeated chromatography on Sephadex LH-20 and on a reversed phase column using Wakosil 40C 18 . In the 1 H NMR spectrum of compound 1, two meta-coupled signals were observed at 6.15 and 6.32, and three signals due to 1,3,4-trisubstituted benzene ring protons at 7.56, 7.51, and 6.82. Moreover, an anomeric proton of a sugar moiety was observed at 5.73 (d, J = 7.9) together with six signals of sugar protons at 5.11–3.33, and the coupling constants of these signals indicated the presence of glucose. The specific optical rotation of 1 also indicated the presence of the -D-glucosyl moiety. In the 1 H– 1 H COSY spectrum, the cross peaks of sugar protons were confirmed, but the signal of the H-2 proton of the glucosyl moiety was observed down field at 5.11. This indicated that the hydroxyl group at the C-2 position of glucose was acylated. The molecular weight of compound 1 and the signal of two proton singlets at 7.12 implied the presence of the galloyl group at C-2 of glucose. The signals at 167.8, 146.3, 139.2, 121.0, and 110.6 in the 13 C NMR spectrum also supported the presence of a galloyl group. These data indicated the presence of quercetin [3], the glycosyl unit [4], and the galloyl group. In the HMBC spectrum, H-1 ( 5.73) of the glycosyl moiety showed a correlation with the signal of C-3 ( 134.9) of quercetin. The carbonyl carbon ( 167.8) of the galloyl moiety also showed correlations with H-2 ( 5.11) and H-2 (7.12). Comparing these data with the literature [5, 6], we characterize compound 1 as quercetin 3-O-(2-O-galloyl)-D-glucoside. Compound 2 showed 1 H MNR spectral data similar to those of compound 1, except for the ortho-coupled two proton signals at 7.95 and 6.89 instead of the signals of 1,3,4-trisubstituted benzene. These data indicated the presence of kaempferol as aglycone. Comparing the 1 H and 13 C NMR data and the specific optical rotation with those in the literature [6], we characterize compound 2 as kaempferol 3-O-(2-O-galloyl)--D-glucoside. The two galloylated flavonoids have been isolated from Diospyros kaki Thunb., Geranium tuberosum subsp. tuberosum and Polygonum lapathifolium L. [7–9], but this is the first report on the isolation of these compounds from the plant belonging to the genus Rosa.

Dipeptidyl peptidase (DPP)‐4 inhibitors are a new class of antidiabetic drugs that increase incretin hormone levels to enhance blood sugar level‐dependent insulinotropic effects, suppress glucagon action, and reduce bowel motility. These incretin effects are ideal for blood sugar control. However, the safety profile of DPP‐4 inhibitors is not yet established. Herein, we present three cases of ileus, considered to be closely related to the use of DPP‐4 inhibitors, in diabetic patients. Each of the three patients exhibited some risk of a deficiency in bowel movement; the onset of ileus was within 40 days after strengthened inhibition of DPP‐4. The use of a DPP‐4 inhibitor could be safe, although the cases presented herein enable us to inform the scientific community to some of the potential adverse effects of the use of DPP‐4 inhibitors in select populations.

To clarify which parameter, diurnal pattern of blood pressure (BP) or level of BP variability, has the stronger predictive value for fatal and nonfatal vascular events, vital status after a mean (+/-SD) follow-up period of 86+/-46 months was determined in 392 type 2 diabetic subjects without any history of vascular disease, in whom the 24-h BP profile had been monitored between 1988 and 1998. After the exclusion of 28 subjects who died during the follow-up period of causes unrelated to diabetes, 364 subjects were recruited for further analysis. A total of 147 first events, including 50 fatal vascular events and 97 nonfatal vascular events, were recorded during the follow-up period. The rates of various vascular events increased with both reduced nocturnal falls in systolic BP (SBP) and levels of all ambulatory BP parameters. The ambulatory BP parameter showing the largest area under the receiver operating characteristic curve (ROCAUC) for fatal events was the mean 24-h pulse pressure (PP), and that for nonfatal events was the mean nighttime SBP; both exceeded the respective values of nocturnal fall in SBP. Furthermore, when dipper and nondipper diabetic subjects were divided into subgroups based on the 24-h PP (54.3 mmHg) and the nighttime SBP (116.5 mmHg) cut-off points derived from the ROC analyses, Kaplan-Meier plots showed that the diabetic subgroups with high ambulatory BP levels had worse outcomes, independent of dipper/nondipper status. Finally, these parameters were applied to the Cox model with the values of nocturnal fall in SBP and other confounding factors, and results showed that mean 24-h PP and mean nighttime SBP predicted fatal and nonfatal vascular events, respectively, more strongly than nocturnal fall in SBP in type 2 diabetic subjects. These findings therefore suggest that ambulatory BP levels in type 2 diabetic subjects have a higher predictive value for organ damage and death compared with diurnal BP patterns or dipper/nondipper status.

It was previously shown that glucagon and epinephrine have additive effects on both gluconeogenic and glycogenolytic flux. However, the changes in gluconeogenic substrates may have been limiting and thus may have prevented a synergistic effect on gluconeogenesis and a reciprocal inhibitory effect on glycogenolysis. Thus the aim of the present study was to determine if glucagon has a greater gluconeogenic and a smaller glycogenolytic effect in the presence of both epinephrine and clamped gluconeogenic precursors. Two groups (Epi and G + Epi + P) of 18-h-fasted conscious dogs were studied. In Epi, epinephrine was increased, and in G + Epi + P, glucagon and epinephrine were increased. Gluconeogenic precursors (lactate and alanine) were infused in G + Epi + P to match the rise that occurred in Epi. Insulin and glucose levels were also controlled and were similar in the two groups. Epinephrine and precursor administration increased glucagon's effect on gluconeogenesis (4.5-fold; P < 0.05) and decreased glucagon's effect on glycogenolysis (85%; P = 0.08). Thus, in the presence of both hormones, and when the gluconeogenic precursor supply is maintained, gluconeogenic flux is potentiated and glycogenolytic flux is inhibited.

Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica. The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria.

Epinephrine increases net hepatic glucose output (NHGO) mainly via increased gluconeogenesis, whereas glucagon increases NHGO mainly via increased glycogenolysis. The aim of the present study was to determine how the two hormones interact in controlling glucose production. In 18-h-fasted conscious dogs, a pancreatic clamp initially fixed insulin and glucagon at basal levels, following which one of four protocols was instituted. In G + E, glucagon (1.5 ng · kg−1· min−1; portally) and epinephrine (50 ng · kg−1· min−1; peripherally) were increased; in G, glucagon was increased alone; in E, epinephrine was increased alone; and in C, neither was increased. In G, E, and C, glucose was infused to match the hyperglycemia seen in G + E (∼250 mg/dl). The areas under the curve for the increase in NHGO, after the change in C was subtracted, were as follows: G = 661 ± 185, E = 424 ± 158, G + E = 1,178 ± 57 mg/kg. Therefore, the overall effects of the two hormones on NHGO were additive. Additionally, glucagon exerted its full glycogenolytic effect, whereas epinephrine exerted its full gluconeogenic effect, such that both processes increased significantly during concurrent hormone administration.

The insulin gene is specifically expressed in beta-cells of the Langerhans islets of the pancreas, and its transcription is regulated by the circulating glucose level. Previous reports have shown that an unidentified beta-cell-specific nuclear factor binds to a conserved cis-regulatory element called RIPE3b and is critical for its glucose-regulated expression. Based on the sequence similarity of the RIPE3b element and the consensus binding sequence of the Maf family of basic leucine zipper transcription factors, we here identified mammalian homologue of avian MafA/L-Maf, an eye-specific member of the Maf family, as the RIPE3b-binding transcriptional activator. Reverse transcription-PCR analysis showed that mafA mRNA is detected only in the eyes and in pancreatic beta-cells and not in alpha-cells. MafA protein as well as its mRNA is up-regulated by glucose, consistent with the glucose-regulated binding of MafA to the RIPE3b element in beta-cell nuclear extracts. In transient luciferase assays, we also showed that expression of MafA greatly enhanced insulin promoter activity and that a dominant-negative form of MafA inhibited it. Therefore, MafA is a beta-cell-specific and glucose-regulated transcriptional activator for insulin gene expression and thus may be involved in the function and development of beta-cells as well as in the pathogenesis of diabetes.

The isolated mantle of scallop (Patinopecten yessoensis) was shown to adsorb minerals (Zn, Ca, Mg, Fe, Cu, Ni and Co) to more than 1% upon treatment with mineral solution. The amounts of adsorbed Zn, Ca and Mg were 44.3, 47.4 and 15.5 mg/g dry weight, when the mantle was treated with 5% ZnSO4, CaCl2 and MgSO4 solutions at room temperature, respectively. The amounts of adsorbed Zn, Ca and Mg were dependent on the concentration of mineral solution used. This is the first report showing that the isolated mantle adsorbs nutritionally important minerals such as Ca, Mg and Fe. This finding may lead to the development of new mineral-enriched food supplements.

A brown alga Chorda filum (L.) Lam. called tsuru-mo in Japanese is harvested and consumed only in a few towns that lie on the coast of the Japan Sea. In Wajima, Ishikawa, Japan, the alga was dried under the sun and stored for 1 year before being sold in retail shops. The dried product of C. filum was washed and rubbed well with plenty of water five to 10 times before cooking. The recovery of crude fucoidan and alginate from dried product was 12 and 16% (w/w), respectively. Molecular ratio of galactose/fucose in the crude fucoidan was lower than 0.1. The ratio of SO4/fucose was about 1.0. Most of the crude fucoidan was lost by washing with 50 volumes of water five times, though half of the crude alginate remained in the washed product.

Gold(I)-containing compounds have long been used in the treatment of rheumatoid arthritis (RA), but the molecular mechanism of their action has remained largely unknown. In this paper we have demonstrated that gold(I) drugs selectively activate the DNA binding of a heterodimer consisting of the basic-leucine zipper transcription factors Nrf2 and small Maf. Once bound to its recognition DNA sequence termed antioxidant-responsive element or Maf-recognition element, Nrf2/small Maf induces a set of antioxidative stress genes, including heme oxygenase-1 and gamma-glutamylcysteine synthetase, whose products have been demonstrated to contribute to the scavenging of reactive oxygen species and to exhibit anti-inflammatory effects. Our findings suggest that stimulation of antioxidative stress response through activation of Nrf2/small Maf may be a pharmacologically important part of the actions of gold(I) drugs for the treatment of rheumatoid arthritis. Alternatively, activation of Nrf2/small Maf may be a protective response of cells against toxic effects of the drugs.

SUMMARY: The mineral (Na, K, Ca, Mg, Fe, Mn and Zn) contents in the holdfast of three brown algae of the genus Laminaria were determined to compare with those in frond and stipe. The wild and cultivated kelps of Laminaria japonica, L. ochotensis, and L. diabolica were used as samples. The K content was markedly high (11.76–14.91 g/100 g dry weight) in the holdfast of cultivated L. japonica; the K/Na ratio (3.88–5.18) of the holdfast was greater than those of frond and stipe as well as the reported values of frond (1.0–2.2). The content of Ca in the holdfasts of these three species was also higher than those in frond and stipe. The content of Mn showed the same tendency. This is the first report showing that the holdfast of L. japonica and L. diabolica is rich in minerals, especially K.

Glucagon-like peptide-1 (7-36)amide (tGLP-1), a representative humoral incretin, released into the portal circulation in response to a meal ingestion, exerts insulinotropic action through binding to the tGLP-1 receptor known to be a single molecular form thus far. We previously reported that the hepatic vagal nerve is receptive to intraportal tGLP-1, but not to non-insulinotropic full-length GLP-1-(1-37), through a mechanism mediated by specific receptor to the hormone. In the present study, we aimed to examine how modification of the receptor function alters this neural reception of tGLP-1, by using the specific agonist, exendin-4, and the specific antagonist, exendin (9-39)amide, of the receptor at doses known to exert their effects on the insulinotropic action of tGLP-1. Intraportal injection of 0.2 or 4.0 pmol tGLP-1, a periphysiological and pharmacological dose, respectively, facilitated significantly the afferent impulse discharge rate of the hepatic vagus in anesthetized rats, as reported previously. However, unexpectedly, intraportal injection of exendin-4 at a dose of 0.2 or 4.0 pmol, or of even 40.0 pmol, did not facilitate the afferents at all. Moreover, intraportal injection of exendin (9-39)amide at 100 times or more molar dose to that of tGLP-1, either 5 min before or 10 min after injection of 0.2 or 4.0 pmol tGLP-1, failed to modify the tGLP-1-induced facilitation of the afferents. The present results suggest that the neural reception of tGLP-1 involves a receptor mechanism distinct from that in the well-known humoral insulinotropic action.

In order to obtain a SiO2 layer as a catalyst support on a surface of aluminum, silica coating on an anodized aluminum plate has been investigated. The catalyst support plate was prepared by impregnating an anodized aluminum plate into silica sol and calcinating it. Results indicated that adding oxalic acid to silica sol is effective in increasing the amount of silica, but adding other acids to the sol form a gel within 100h. The amount of silica applied increases with an increase in the temperature and the impregnation time. However, the amount decreased as the amount of alumina layer that had dissolved increased. The BET surface area of the coated specimens increased as the Si content increased. The maximum surface area relative to the apparent geometrical surface area was approximately 6000m2·m-2, which was more than twice that before coating, demonstrating that it is possible to apply the coating as a catalyst support. Results of plate characterization indicated that the alumina layer formed by anodizing dissolved in the presence of oxalic acids enlarging the pores that were then filled with silica particles.

To assess the roles of various mitochondrial (Mt) DNA mutations in diabetic and nondiabetic subjects, we screened Mt DNAs at the 3243 base pair (bp) and its adjacent portion in unrelated Japanese diabetic and nondiabetic subjects. Furthermore, to clarify the clinical features of diabetic subjects harboring a Mt DNA mutation, we evaluated the ability of insulin secretion and microvascular complications in diabetic subjects. Five hundred thirty-seven diabetic patients and 612 unrelated nondiabetic subjects were recruited into this study. In Mt DNA analyses, Mt DNA was isolated from peripheral leukocytes of the subjects, and then an Mt DNA fragment surrounding the tRNA(Leu(UUR)) site was amplified by the polymerase chain reaction (PCR) using two sets of primers. These fragments were further digested with three kinds of restriction endonucleases and were subjected to agarose gel electrophoresis. When a mutation was present, Mt DNA fragments were directly sequenced with an autosequencer. Baseline characteristics in all subjects were examined, and microvascular complications and insulin secretory capacity in diabetic subjects were newly evaluated. Eight kinds of Mt DNA mutations, which were point mutations, were found in 74 subjects. Each affected subject had only one mutation in the Mt DNA examined. Among them, the mutations at np 3316, 3394, 3593, and 3391 were accompanied by amino acid replacement. Thirty-eight diabetic patients were affected (7.1%), including two subjects with a point mutation at np 3243, and 26 nondiabetic subjects were affected (4.2%). Thus, there was a higher prevalence in diabetic subjects than in nondiabetic subjects. There was no significant difference in the prevalence of maternally inherited diabetes between these two groups. The mean level of urinary C-peptide excretion was lower in diabetic subjects with an Mt DNA mutation (DM+) than in those without it (DM-). Although the prevalence of hypertension in DM+ was higher than that in DM-, diabetic retinopathy and nephropathy in DM+ were problematic, in comparison with those in DM-, when statistical corrections were performed for the effect of hypertension. Furthermore, a strategy based on logistic regression analysis revealed that advanced retinopathy and decreased urinary C-peptide excretion in all diabetic subjects studied were strongly related to the presence of Mt DNA mutation. Our results suggest that Mt DNA mutations in Japanese diabetic subjects are related to the development of diabetes, and also that these mutations are associated with not only a decrease in insulin secretion but also advanced diabetic microvascular complications.

To elucidate the regulatory mechanisms underlying lens development, we searched for members of the large Maf family, which are expressed in the mouse lens, and found three, c-Maf, MafB, and Nrl. Of these, the earliest factor expressed in the lens was c-Maf. The expression of c-Maf was most prominent in lens fiber cells and persisted throughout lens development. To examine the functional contribution of c-Maf to lens development, we isolated genomic clones encompassing the murine c-maf gene and carried out its targeted disruption. Insertion of the beta-galactosidase (lacZ) gene into the c-maf locus allowed visualization of c-Maf accumulation in heterozygous mutant mice by staining for LacZ activity. Homozygous mutant embryos and newborns lacked normal lenses. Histological examination of these mice revealed defective differentiation of lens fiber cells. The expression of crystallin genes was severely impaired in the c-maf-null mutant mouse lens. These results demonstrate that c-Maf is an indispensable regulator of lens differentiation during murine development.

To investigate the significance of reversed circadian blood pressure (BP) rhythm as a predictor for diabetic endstage renal failure, introduction of hemodialysis (HD) was determined as an end point in 325 non–insulin-dependent diabetes mellitus (NIDDM) subjects, in whom 24-h BPs had been monitored during their first admissions between 1988 and 1996. Circadian BP rhythm was analyzed by the COSINOR method, as previously reported. After exclusion of 68 dropout subjects, 257 were recruited for further analyses, in which 194 had normal circadian BP rhythms (N), and the remaining 63 had reversed rhythms (R). During this follow-up period, the numbers of HD-introduced subjects in N and R were 6 and 16, respectively, showing a higher prevalence in the latter (p < 0.001, χ2 test). Follow-up periods were significantly shorter in HD-introduced diabetic subjects of N and R than those in HD-free subjects of each group. In baseline characteristics, there were no differences in age, gender, or serum creatinine between HD-free and HD-introduced subjects of N or R. With regard to microvascular complications, the degree of retinopathy and nephropathy in N and R tended to be more pronounced in HD-introduced subjects than in HD-free subjects. Further, mean levels of circadian mean BP rhythms in HD-introduced subjects of N or R were similarly high, compared with those in HD-free subjects of each group, irrespective of circadian BP pattern. Unadjusted HD-free times were estimated by the Kaplan–Meier method, with a significant difference noted between N and R (p < 0.001; log-rank test). The Cox proportional-hazards model adjusted for circadian BP pattern, age, gender, hlood pressure level, glycemic control, duration of diabetes, serum total protein, and serum creatinine demonstrated that circadian BP pattern, age, gender (female), blood pressure level (hypertension), and serum creatinine exhibited significant high relative risks. Thus, our data suggest that reversed circadian BP rhythm is an independent predictor of endstage renal failure in NIDDM subjects.

We have studied the enthalpy relaxation of glassy glycerol prepared by quenching of the liquid in a top-loading type adiabatic calorimeter developed by our group. The glassy sample was prepared by plunging the sample cell into liquid nitrogen. The cooling rate, 5 K s −1 , was about 100 times faster than the rate available in ordinary adiabatic calorimeters. The heat capacity of the rapidly quenched glass (RQG) was only slightly different from that of the normally quenched glass (NQG). RQG released much larger enthalpy than NQG and the relaxations started at a much lower temperature than the glass transition temperatures of NQG. We analyzed these data in terms of the Adam–Gibbs theory. We demonstrate that the relaxation is accelerated by the larger configurational entropy (prominent structural disorder).