Peroxynitrite scavenging activities of aromatic compounds isolated from Konnyaku, Amorphophallus konjac K.Koch.
(+/-)-5,5'-Dimethoxysesamin, erythrinasinate, indole-3-carbaldehyde, (7R,8S)-dihydrodehydrodiconiferyl alcohol 9-O-beta-D-glucopyranoside, cis- and trans-N-(p-coumaroyl)serotonin, serotonin, 3,4-dihydroxybenzoic acid, and 3,4-dihydroxybenzaldehyde have been found in tobiko, a food by-product, and evaluation of their peroxynitrite scavenging activities has been done. Among these compounds, serotonin, trans-N-(p-coumaroyl)serotonin, 3,4-dihydroxybenzaldehyde, and 3,4-dihydroxybenzoic acid showed stronger activities than that of BHT (butylated hydroxytoluene) at 200 microM. (+info
Effects of konjac extract on insulin sensitivity in high fat diet rats.
AIM: To evaluate the effects of konjac extract (KE) on insulin sensitivity in insulin resistance (IR) rats induced by high fat diet (HFD). METHODS: Wistar rats were fed on HFD for 4 weeks, then treated with KE 1.5, 3.0 g/kg/d and metformin (Met) 0.1 g/kg/d for 4 weeks, respectively. The effects of KE on intake of food and drink, body weight, and excretion were investigated. Serum insulin was measured by double-radioimmunoassay. Blood glucose, total cholesterol (TC), triglycerides (TG), and high-density lipoprotein-cholesterol (HDL-C) were measured by enzyme methods, respectively. Low-density lipoprotein-cholesterol (LDL-C) was calculated. Tissue glycogen was determined by modified anthracene ketone method and tissue TG by glycerin phosphor sour oxidation enzyme method. Insulin sensitivity was measured by modified glucose-insulin tolerance test (K value). RESULTS: HFD caused IR after 4 weeks (K value: 5.2+/-0.9 vs 8.3+/-0.7, P<0.01), the levels of blood insulin, TG, and LDL-C increased, while HDL-C, glycogen in liver and skeletal muscle decreased. The storage of TG in liver and skeletal muscle increased. After HFD rats were treated with KE 1.5 and 3.0 g/kg/d for 4 weeks, respectively, the fasting blood glucose (FBG) was decreased from 6.4+/-0.4 to 6.05+/-0.26, 6.0+/-0.3 (P<0.01). Serum TC, TG, LDL-C were decreased, while HDL-C/TC was increased as compared with HFD rats. There was no significant effect on insulin level. KE 1.5, 3.0 g/kg/d, and Met 0.1 g/kg/d could improve insulin sensitivity (K values were 6.1+/-0.5, 5.9+/-0.6, and 6.5+/-0.8 vs 5.2+/-0.9, P<0.05), elevate glycogen, and decrease TG in liver and skeletal muscle. CONCLUSION: KE could promote glycogen syntheses and adjust blood lipid metabolism so as to improve IR in HFD rats. (+info
Hypersensitivity pneumonitis induced by Konjak flour and powdered Hijikia fusiforme.
This is a report of a patient with occupational hypersensitivity pneumonitis (HP) caused by Konjak flour and powdered Hijikia fusiforme. A 56-year-old man had worked as a Konnyaku manufacturer for 38 years, and suffered from dyspnea on exertion. Konnyaku is a paste made from Konjak flour, powdered Hijikia fusiforme, quicklime, and powdered scallop shell. The diagnosis of HP was confirmed immunologically by the detection of serum precipitins to powdered Hijikia fusiforme, and by the positive result of in vitro lymphocytic proliferative response for Konjak flour using peripheral blood lymphocytes. To our knowledge, this is the first case report of Konnyaku manufacturer's lung. (+info
Unusual metaxylem tracheids in petioles of Amorphophallus (Araceae) giant leaves.
BACKGROUND AND AIMS: Petioles of huge solitary leaves of mature plants of Amorphophallus resemble tree trunks supporting an umbrella-like crown. Since they may be 4 m tall, adaptations to water transport in the petioles are as important as adaptations to mechanical support of lamina. The petiole is a cylindrical shell composed of compact unlignified tissue with a honeycomb aerenchymatous core. In both parts numerous vascular bundles occur, which are unique because of the scarcity of lignified elements. In the xylemic part of each bundle there is a characteristic canal with unlignified walls. The xylem pecularities are described and interpreted. MATERIAL: Vascular bundles in mature petioles of Amorphophallus titanum and A. gigas plants were studied using light and scanning electron microscopy. KEY RESULTS: The xylemic canal represents a file of huge metaxylem tracheids (diameter 55-200 microm, length >30 mm) with unlignified lateral walls surrounded by turgid parenchyma cells. Only their end walls, orientated steeply, have lignified secondary thickenings. The file is accompanied by a strand of narrow tracheids with lignified bar-type secondary walls, which come into direct contact with the wide tracheid in many places along its length. CONCLUSIONS: The metaxylem tracheids in A. petioles are probably the longest and widest tracheids known. Only their end walls have lignified secondary thickenings. Tracheids are long due to enormous intercalary elongation and wide due to a transverse growth mechanism similar to that underlying formation of aerenchyma cavities. The lack of lignin in lateral walls shifts the function of 'pipe walls' to the turgid parenchyma paving the tracheid. The analogy to carinal canals of Equisetum, as well as other protoxylem lacunas is discussed. The stiff partitions between the long and wide tracheids are interpreted as structures similar to the end walls in vessels. (+info
A novel method for measuring dissolution kinetics of pulverized konjac flour.
The aim of the current study was to explore a novel method for measuring hydration and dissolution kinetics of the pulverized konjac flour (PK flour) from Amorphophallus albus using RVA-3D+ Rapid Visco Analyzer (RVA; Newport Scientific Pty Ltd., Australia). The results showed that RVA was a reliable fast technique for determining the hydration curve of PK flour. The test conditions determining the hydration curves were optimized at the concentration of PK flour with 1.0%, test temperature at 30+/-1oC, stirring speed at 160 RPM (Revolution Per Minute), and test time of 16 min. An empirical exponential model has also been established to describe the dis-solution kinetics of PK flour at the concentration of 1.0%: eta= 161.9343.EXP (-2.1522/tau) (R2=0.9762) Where tau is the test time (min); eta is the viscosity of the hydration process (RVU) of PK flour. The results also showed that a significant difference among the hydration curves of 1.0% PK flour when dispersed in distilled water and in different concentrations of sucrose aqueous solution. (+info
Soluble fiber viscosity affects both goblet cell number and small intestine mucin secretion in rats.
Antioxidant and hepatoprotective activity of ethanolic and aqueous extracts of Amorphophallus campanulatus Roxb. tubers.
In the present study, the hepatoprotective activity of ethanolic and aqueous extracts of Amorphophallus campanulatus (Roxb.) tubers were evaluated against carbon tetrachloride (CCl4) induced hepatic damage in rats. The extracts at a dose of 500 mg/kg were administered orally once daily. The substantially elevated serum enzymatic levels were significantly restored towards normalization by the extracts. Silymarin was used as a standard reference and exhibited significant hepatoprotective activity against carbon tetrachloride induced haptotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that Amorphophallus campanulatus (Roxb.) tubers have potent hepatoprotective action against carbon tetrachloride induced hepatic damage in rats. The ethanolic extract was found hepatoprotective more potent than the aqueous extract. The antioxidant activity was also screened and found positive for both ethanolic and aqueous extracts. This study suggests that possible mechanism of this activity may be due to free radical scavenging potential caused by the presence of flavonoids in the extracts. (+info
Chemical identity of a rotting animal-like odor emitted from the inflorescence of the titan arum (Amorphophallus titanum).
The titan arum, Amorphophallus titanum, is a flowering plant with the largest inflorescence in the world. The flower emits a unique rotting animal-like odor that attracts insects for pollination. To determine the chemical identity of this characteristic odor, we performed gas chromatography-mass spectrometry-olfactometry analysis of volatiles derived from the inflorescence. The main odorant causing the smell during the flower-opening phase was identified as dimethyl trisulfide, a compound with a sulfury odor that has been found to be emitted from some vegetables, microorganisms, and cancerous wounds. (+info