Selective isolation of acidophilic streptomyces strains for glucose isomerase production

Approximately 260 Streptomyces strains were isolated from neutral pH farmland soil and evaluated for their ability to produce glucose isomerase. The number of acidophilic Streptomyces organisms growing at pH 4.0 was low, i.e., 10 organisms per g of soil. All of the isolates showed glucose isomerase activity when they were grown in a medium containing d-xylose, an inducer for glucose isomerase. More than half of the strains tested developed heavy growth in 24 h, and many produced high titers of glucose isomerase after 24 h of growth in a medium buffered at pH 5.0.

Hypocholesterolemic and antioxidant properties of 3-(4-hydroxyl)propanoic acid derivatives in high-cholesterol fed rats

The purpose of the present study was to evaluate the in vivo efficacy of two cinnamic acid synthetic derivatives (allyl 3-[4-hydroxyphenyl]propanoate; HPP304, 1-naphthyl-methyl 3-[4-hydroxyphenyl]propanoate; HPP305) in high-cholesterol fed rats and compare their actions to that of cinnamic acid. Cinnamic acid and its synthetic derivatives were supplemented with a high-cholesterol diet for 42 days at a dose of 0.135 mmol/100g of diet. The supplementation of HPP304 and HPP305 significantly lowered cholesterol and triglyceride levels in the plasma and liver with a simultaneous increase in the HDL-cholesterol concentration, whereas cinnamic acid only lowered the plasma cholesterol concentration. Cinnamic acid lowered hepatic HMG-CoA reductase activity in high-cholesterol fed rats, however, its synthetic derivatives (HPP304 and HPP305) did not affect HMG-CoA reductase activity compared to the control group. Instead, the HPP304 and HPP305 supplements significantly lowered hepatic acyl coenzyme A:cholesterol acyltransferase activity and increased the fecal bile acid. The SOD activity of the erythrocytes and liver was not different between the groups, however, the activities of CAT and GSH-Px, and the level of GSH in the erythrocytes were significantly higher in the HPP304 and HPP305 groups than in the control group. On the other hand, the activities of CAT and GSH-Px, and the level of malondialdehyde in the liver were significantly lower in the HPP304 and HPP305 groups. The antioxidant activities of these cinnamic acid synthetic derivatives were similar to the cinnamic acid in the high-cholesterol fed rats. In addition, HPP304 and HPP305 lowered amniotransferase activity in the plasma. These results suggest that two cinnamic acid synthetic derivatives (HPP304 and HPP305) exert lipid-lowering action and antioxidant properties without hepatotoxicity in high-cholesterol fed rats.

Naphthalenemethyl ester derivative of dihydroxyhydrocinnamic acid, a component of cinnamon, increases glucose disposal by enhancing translocation of glucose transporter 4

AIMS/HYPOTHESIS

Cinnamon extracts have anti-diabetic effects. Phenolic acids, including hydrocinnamic acids, were identified as major components of cinnamon extracts. Against this background we sought to develop a new anti-diabetic compound using derivatives of hydroxycinnamic acids purified from cinnamon.

METHODS

We purified hydroxycinnamic acids from cinnamon, synthesised a series of derivatives, and screened them for glucose transport activity in vitro. We then selected the compound with the highest glucose transport activity in epididymal adipocytes isolated from male Sprague-Dawley rats in vitro, tested it for glucose-lowering activity in vivo, and studied the mechanisms involved.

RESULTS

A naphthalenemethyl ester of 3,4-dihydroxyhydrocinnamic acid (DHH105) showed the highest glucose transport activity in vitro. Treatment of streptozotocin-induced diabetic C57BL/6 mice and spontaneously diabetic ob/ob mice with DHH105 decreased blood glucose levels to near normoglycaemia. Further studies revealed that DHH105 increased the maximum speed of glucose transport and the translocation of glucose transporter 4 (GLUT4, now known as solute carrier family 2 [facilitated glucose transporter], member 4 [SLC2A4]) in adipocytes, resulting in increased glucose uptake. In addition, DHH105 enhanced phosphorylation of the insulin receptor-beta subunit and insulin receptor substrate-1 in adipocytes, both in vitro and in vivo. This resulted in the activation of phosphatidylinositol 3-kinase and Akt/protein kinase B, contributing to the translocation of GLUT4 to the plasma membrane.

CONCLUSIONS/INTERPRETATION

We conclude that DHH105 lowers blood glucose levels through the enhancement of glucose transport, mediated by an increase in insulin-receptor signalling. DHH105 may be a valuable candidate for a new anti-diabetic drug.

Supplementation of whole persimmon leaf improves lipid profiles and suppresses body weight gain in rats fed high-fat diet

The objective of this study was to investigate the hypolipidemic effects of powdered whole persimmon leaf supplement in rats fed high-fat diet. Three groups of male Sprague-Dawley rats during 6 weeks were fed different diet: normal control (NC), high-fat (HF), and high-fat supplemented with powdered whole persimmon leaf (PL; 5%, wt/wt) groups. Body weight and relative weight of interscapular brown adipose tissue were significantly lower in the PL group than in the HF group, while plasma leptin concentration was higher. The supplementation of persimmon leaf significantly lowered the plasma total cholesterol and triglyceride concentrations, whereas elevated the ratio of HDL-C/total-C and improved the atherogenic index. Persimmon leaf supplementation led the hepatic cholesterol and triglyceride values to similar levels to the NC group. Accumulation of hepatic lipid droplets and the epididymal white adipocyte size of PL group were diminished comparing to the HF group. Hepatic HMG-CoA and ACAT activities were significantly higher in the PL group than in other groups. Contents of fecal triglyceride, cholesterol and acidic sterol were significantly higher in the PL group than in the HF group. Accordingly, we suggest that supplementation of the powdered whole persimmon leaf improves plasma and hepatic lipid levels profile partly via the increased fecal lipids in high-fat fed rats. These beneficial effects may be due to the properties of its phenolic compounds (1.15 g/100g) and high fiber (63.48 g/100g) content in the powdered persimmon leaf.

Comparison of antioxidant effects of naringin and probucol in cholesterol-fed rabbits

BACKGROUND

Due to the strong evidence on the involvement of active oxygen species in a variety of disorders, the role of antioxidants against oxidative stress has recently received increased attention.

METHODS

Twenty male rabbits were served a high-cholesterol (HC, 5 g/kg diet) diet or high-cholesterol diet supplemented with naringin (0.5 g/kg diet) or probucol (0.5 g/kg diet) for 8 weeks to compare the antioxidative effects of the citrus bioflavonoid (naringin) and antioxidative cholesterol-lowering drug (probucol).

RESULTS

The plasma thiobarbituric acid-reactive substances (TBARS) concentration was not significantly different between the groups, whereas the hepatic TBARS concentration was significantly lower in the probucol group than in both normal and HC control or naringin group. Probucol and naringin supplementation led to an increase in the hepatic superoxide dismutase (SOD) and catalase (CAT) activities, and a decrease in the hepatic mitochondrial hydrogen peroxide (H(2)O(2)) content compared to the HC-control group. However, there was no difference in the cytosolic H(2)O(2) content or cytosolic glutathion peroxidase (GSH-Px) activity in the liver between the groups. Both naringin and probucol supplements significantly increased the plasma vitamin E concentration compared to the HC-control group. As regards the antioxidant enzyme gene expressions, naringin significantly increased the expression of three antioxidant enzyme mRNAs compared to the HC-control group, whereas probucol significantly increased the only SOD mRNA expression.

CONCLUSIONS

The probucol supplement was very potent in the antioxidative defense system, whereas naringin exhibited a comparable antioxidant capacity based on increasing the gene expressions in the antioxidant enzymes, while also increasing the hepatic SOD and CAT activities, sparing plasma vitamin E, and decreasing the hepatic mitochondrial H(2)O(2) content.

Low-density lipoprotein-antioxidant constituents of Saururus chinensis

A new diarylbutane lignan, saururin A (1), and a known 8-O-4'-type neolignan, machilin D (2), were isolated from a total methanol extract of the underground parts of Saururus chinensis. The structures of 1 and 2 were elucidated by spectroscopic data analysis. Compounds 1, 2, and virolin (3) (the methyl ether of 2) exhibited significant low-density lipoprotein (LDL)-antioxidant activity in the thiobarbituric acid-reactive substance (TBARS) assay with IC(50) values of 8.5, 2.9, and 4.3 microM, respectively.

Naringin has an antiatherogenic effect with the inhibition of intercellular adhesion molecule-1 in hypercholesterolemic rabbits

Naringin, a bioflavonoid found in citrus fruit peel, is known to have an antioxidative effect, but its effect on atherosclerosis has not been studied. This study evaluated the effect of naringin on blood lipid levels and aortic fatty streaks, and its action mechanism in hypercholesterolemic rabbits. Male New Zealand white rabbits were fed a 0.25% cholesterol diet and divided into an untreated group (n = 4), a naringin-treated group (n = 5; 500 mg/kg per day), and a lovastatin-treated group (n = 5; 20 mg/kg per day). After 8 weeks, blood was sampled and analyzed biochemically. Aorta and liver were harvested and examined histologically. Cholesterol level in rabbits fed the 0.25% cholesterol diet reached 17 times normal and decreased in the rabbits fed naringin and lovastatin, whose effects were not statistically significant (p > 0.05). However, both naringin and lovastatin effectively decreased the area of fatty streak in thoracic aorta on macroscopic analysis (p < 0.05) and significantly reduced subintimal foam cell infiltration on microscopic morphometry (p < 0.05). These foam cells were macrophages on immunohistochemical analysis. Naringin treatment inhibited hypercholesterolemia-induced intercellular adhesion molecule-1 (ICAM-1) expression on endothelial cells. Hypercholesterolemia caused fatty liver and elevation of liver enzymes, which was prevented by naringin but not by lovastatin. Naringin significantly reduced fatty streak formation and neointimal macrophage infiltration and also inhibited the expression of ICAM-1 in endothelial cells, suggesting that suppression of ICAM-1 contributed to the antiatherogenic effect. Naringin, unlike lovastatin, has a hepatoprotective action.

Lipid-lowering and antioxidative activities of 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate in cholesterol-fed rats

BACKGROUND

Polyphenols appear to have antioxidant activities and may mediate lipid lowering.

METHODS

Four groups of rats, a high-cholesterol control (HC), HC+lovastatin, HC+3,4-di(OH)-cinnamate, and HC+3,4-di(OH)-hydrocinnamate, were given a semi-synthetic diet. The cinnamate derivative or lovastatin (0.1 g/100 g) supplements were given for 6 weeks.

RESULTS

The plasma total cholesterol concentration was significantly lowered by the 3,4-di(OH)-cinnamate supplement compared to the control or lovastatin group. The 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate supplements significantly lowered both the hepatic cholesterol and triglyceride levels, while lovastatin only lowered the hepatic cholesterol. The hepatic HMG-CoA reductase activities were significantly lower in the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate groups than in the control or lovastatin group. The ACAT activity was only significantly lower in the lovastatin group compared to the other groups. With regards the hepatic antioxidant enzyme system, the CAT activity was significantly higher in the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate groups compared to the control or lovastatin group. The two cinnamate derivatives resulted in an increased hepatic GSH-Px activity. Meanwhile, all the supplements significantly lowered the hepatic thiobarbituric acid reactive substances (TBARS) content. However, the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate supplements did not alter the neutral sterol and total fecal sterol.

CONCLUSIONS

Both cinnamate derivatives were potent in lipid-lowering and altering the antioxidative enzyme. Furthermore, these results also suggest that 3,4-di(OH)-cinnamate is more effective than 3,4-di(OH)-hydrocinnamate in its lipid-lowering action.

Effect of naringin supplementation on cholesterol metabolism and antioxidant status in rats fed high cholesterol with different levels of vitamin E

Some bioflavonoids are potent antioxidants and have pharmacological effects similar to those of vitamin E. The interactive effect of naringin and vitamin E was studied with respect to cholesterol metabolism and antioxidant status. Naringin supplementation (0.1%, wt/wt) with comparable levels of vitamin E was given to rats with a high-cholesterol (1%, wt/wt) diet for 5 weeks. The amount of vitamin E included in naringin-free and naringin diets was a low (low-E) and a normal (normal-E) level. The naringin supplementation significantly lowered the concentrations of plasma cholesterol and triglyceride compared to the naringin-free group in low vitamin E-fed rats. HMG-CoA reductase activity was significantly lowered by naringin supplementation within both the low-vitamin E group (794.64 +/- 9.87 vs. 432.18 +/- 12.33 pmol/min/mg protein, mean +/- SE; p < 0.05) and normal-vitamin E group (358.82 +/- 11.4 vs. 218.22 +/- 9.47 pmol/min/mg protein, mean +/- SE; p < 0.05) compared to each of the naringin-free group. The HMG-CoA reductase activity was also significantly lowered by increased dietary vitamin E when compared within the naringin and naringin-free group, respectively. Neither dietary naringin nor vitamin E did significantly change the activities of hepatic antioxidant enzymes and plasma thiobarbituric acid-reactive substance level. These data indicate that naringin lowers the plasma lipid concentrations when the dietary vitamin E level is low. The HMG-CoA reductase-inhibitory effect of naringin was more potent when dietary vitamin E was at a normal level. These data may contribute to understanding the interactive effect of naringin and vitamin E on cholesterol biosynthesis in high-cholesterol-fed rats.

Antioxidative activity of naringin and lovastatin in high cholesterol-fed rabbits

The consumption of a cholesterol-enriched diet increases the degree of lipid peroxidation, which is one of the early processes of atherosclerosis. The aim of this trial was to determine the antioxidative effects of the citrus bioflavonoid, naringin, a potent cholesterol-lowering agent, compared to the cholesterol-lowering drug, lovastatin, in rabbits fed a high cholesterol diet. Male rabbits were served a high-cholesterol (0.5%, w/w) diet or high-cholesterol diet supplemented with either naringin (0.5% cholesterol, 0.05% naringin, w/w) or lovastatin (0.5% cholesterol, 0.03% lovastatin, w/w) for 8 weeks to determine the plasma and hepatic lipid peroxide, plasma vitamin A and E levels, and hepatic hydrogen peroxide levels, along with the hepatic antioxidant enzyme activities and gene expressions. Only the lovastatin group showed significantly lower plasma and hepatic lipid peroxide levels compared to the control group. The naringin supplementation significantly increased the activities of both hepatic SOD and catalase by 33% and 20%, respectively, whereas the lovastatin supplementation only increased the catalase activity by 23% compared to control group. There was no difference in the GSH-Px activities between the various groups. Content of H2O2 in hepatic mitochondria was significantly lower in groups supplemented with lovastatin and naringin than in control group. However, there was no difference in cytosolic H2O2 content in liver between groups. The concentration of plasma vitamin E was significantly increased by the naringin supplementation. When comparing the antioxidant enzyme gene expression, the mRNA expression of SOD, catalase and GSH-Px was significantly up-regulated in the naringin-supplemented group. Accordingly, these results would appear to indicate that naringin, a citrus bioflavonoid, plays an important role in regulating antioxidative capacities by increasing the SOD and catalase activities, up-regulating the gene expressions of SOD, catalase, and GSH-Px, and protecting the plasma vitamin E. In contrast, lovastatin exhibited an inhibitory effect on the plasma and hepatic lipid peroxidation and increased the hepatic catalase activity in high-cholesterol fed rabbits.

Dietary hematein ameliorates fatty streak lesions in the rabbit by the possible mechanism of reducing VCAM-1 and MCP-1 expression

Hematein is a compound isolated from Caesalpinia sappan that has been used in oriental medicine as both an analgesic and an anti-inflammatory agent. In this study, we examined the anti-atherogenic potential of hematein using cholesterol-fed New Zealand White (NZW) rabbits. NZW rabbits were divided into a hematein-supplemented (0.05% in diet) group (n=6), a probucol-supplemented (0.25% in diet) group (n=6), and a control group (n=6). After 8 weeks of treatments, the extent of the atherosclerotic lesions was significantly reduced in the hematein-supplemented group and the probucol-supplemented group without changing plasma lipoprotein levels. Hematein and probucol prevented the up-regulation of the vascular cell adhesion molecule-1 (VCAM-1) expression on the descending aorta induced by cholesterol diet. In culture, hematein also significantly inhibited the secretion of soluble VCAM-1 and of monocyte chemotactic protein-1 (MCP-1) respectively induced by tumor necrotic factor alpha (TNF-alpha) and mildly oxidized low density lipoprotein in human umbilical vein endothelial cell (HUVEC) culture. Also, hematein inhibited monocyte adhesion to endothelial cell and the activation of NF-kappaB in HUVECs stimulated with TNF-alpha. The results of the present study suggest that the anti-atherogenic effect of hematein is not related to control of the plasma lipid profile but probably related to the inhibition of VCAM-1 and MCP-1 expression resulting in an amelioration of lesion development in the rabbit.

Inhibitory activity for chitin synthase II from Saccharomyces cerevisiae by tannins and related compounds

In the course of search for potent inhibitors of chitin synthase II from natural resources, seven tannins and related compounds were isolated from the aerial part of Euphorbia pekinensis and identified as gallic acid (1), methyl gallate (2), 3-O-galloyl-(-)-shikimic acid (3), corilagin (4), geraniin (5), quercetin-3-O-(2"-O-galloyl)-beta-D-glucoside (6), and kaempferol-3-O-(2"-O-galloyl)-beta-D-glucoside (7). These and nine related compounds, (-)-quinic acid (8), (-)-shikimic acid (9), ellagic acid (10), kaempferol (11), quercetin (12), quercitrin (13), rutin (14), quercetin-3-O-(2"-O-galloyl)-beta-D-rutinoside (15) and 1,3,4,6-tetra-O-galloyl-beta-D-glucose (16), were evaluated for the inhibitory activity against chitin synthase II and III. They inhibited chitin synthase II with IC(50) values of 18-206 microM, except for two organic acids, (-)-quinic acid (8) and (-)-shikimic acid (9). Among them, 3-O-galloyl-(-)-shikimic acid (3) was the most potent inhibitor against chitin synthase II of Saccharomyces cerevisiae with an IC(50) value of 18 microM. The inhibition appears to be selective for chitin synthase II, as they did not appreciably inhibit chitin synthase III.

Anti-atherogenic effect of citrus flavonoids, naringin and naringenin, associated with hepatic ACAT and aortic VCAM-1 and MCP-1 in high cholesterol-fed rabbits

The anti-atherogenic effects of the citrus flavonoids, naringin and naringenin, were evaluated in high cholesterol-fed rabbits. At 3 months of age, 30 male New Zealand White (NZW) rabbits were divided into three groups (n = 10 per group). The rabbits were fed a 1% cholesterol diet alone (control group) or a diet supplemented with either 0.1% naringin or 0.05% naringenin for 8 weeks. The plasma lipoprotein levels, total cholesterol, triglyceride, and high-density lipoprotein showed no significant differences in the control and experimental groups. Hepatic acyl-CoA:cholesterol acyltransferase (ACAT) activity was slightly low in naringin (5.0%)- and naringenin (15.0%)-fed rabbits, compared to control group. The aortic fatty streak areas were significantly lower in both the naringin (19.2 +/- 5.6%)- and naringenin (18.1 +/- 6.5%)-supplemented groups than in the control group (60.4 +/- 14.0%). The expression levels of vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemotactic protein-1 (MCP-1), by semiquantitative RT-PCR analysis of the thoracic aorta, were significantly lower in the flavonoids supplemented groups than in the control group. These results suggest that the anti-atherogenic effect of the citrus flavonoids, naringin and naringenin, is involved with a decreased hepatic ACAT activity and with the downregulation of VCAM-1 and MCP-1 gene expression.

Interactive effect of hesperidin and vitamin E supplements on cholesterol metabolism in high cholesterol-fed rats

Certain bioflavonoids are potent antioxidants and have pharmacologic effects similar to those of vitamin E. Accordingly, the interactive effect of hesperidin and vitamin E was studied with respect to cholesterol metabolism and the antioxidant status. Hesperidin supplement (0.1%, wt/wt) with comparable levels of vitamin E was provided with a high-cholesterol (1%, wt/wt) diet to rats for 5 weeks. The amount of vitamin E included in the hesperidin-free and hesperidin diets was either a low (low-E) or a normal (normal-E) level. The hesperidin supplement and different levels of dietary vitamin E did not significantly alter the concentrations of plasma triglycerides. However, the inclusion of hesperidin significantly lowered the concentration of plasma cholesterol in both the low-vitamin E group and the normal-vitamin E group compared to the hesperidin-free groups (p < 0.05). The hepatic triglyceride content was significantly lowered by the hesperidin supplement, as opposed to the plasma triglyceride content, regardless of the vitamin E level in the diet. The hepatic HMG-CoA reductase activity was significantly lowered by the hesperidin supplement with both the low-vitamin E and the normal-vitamin E compared to the hesperidin-free groups (p < 0.05). The hepatic HMG-CoA reductase activity was also significantly lowered with an increase in the dietary vitamin E within the hesperidin and hesperidin-free groups. The excretion of fecal neutral sterol and acidic sterols tended to be lower with the hesperidin supplement. Neither dietary hesperidin nor vitamin E significantly changed the hepatic antioxidant enzyme activity. This data indicates that hesperidin lowers the concentration of plasma cholesterol and the hepatic triglyceride content regardless of the dietary vitamin E level. However, the concentration of plasma cholesterol in the hesperidin-free groups was dependent on the dietary vitamin E level. This information may contribute to understanding the interactive effect of hesperidin and vitamin E on cholesterol biosynthesis in high cholesterol-fed rats.

Cholesterol-lowering activity of naringenin via inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase and acyl coenzyme A:cholesterol acyltransferase in rats

The effects of dietary supplementation of a citrus bioflavonoid, naringenin, on the cholesterol metabolism were studied. For 42 days male rats were fed a 1% (wt/wt) high-cholesterol diet with or without a naringenin supplementation (0.1%, wt/wt) to study its effect on plasma lipid levels, hepatic lipid contents, activities of hepatic acyl coenzyme A:cholesterol O-acyltransferase (ACAT) and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, and the excretion of fecal neutral sterols. Naringenin did not significantly alter the concentration of plasma triglycerides, but lowered the plasma cholesterol (3.80 vs. 3.12 mmol/l) concentration and the hepatic cholesterol content (70.3 vs. 54.0 mg/g) significantly (p < 0.05) compared to those of the controls. HMG-CoA reductase (1,879.0 vs. 1,715.0 pmol/min/mg) and ACAT activities (806.0 vs. 563.0 pmol/min/mg) were significantly lower in the naringenin-supplemented group than in controls. Naringenin supplementation caused a marked decrease in the excretion of fecal neutral sterols (242.9 mg/day) compared to the controls (521.9 mg/day). These results show that naringenin lowers the plasma and hepatic cholesterol concentrations by suppressing HMG-CoA reductase and ACAT in rats fed a high-cholesterol diet.

Hypocholesterolemic effect of naringin associated with hepatic cholesterol regulating enzyme changes in rats

The effects of the citrus bioflavonoid naringin were tested by using it as a supplement in a high-cholesterol diet. Male rats were fed for 42 days with a 1% (wt/wt) high cholesterol diet either with or without naringin-supplementation (0.1%, wt/wt) to study the effect on plasma lipid levels, hepatic lipid contents, hepatic enzyme activity, and the excretion of fecal neutral sterols. Naringin did not significantly alter the levels of plasma triglycerides, however, the levels of plasma cholesterol (3.80 +/- 0.31 mmol/L vs. 2.61 +/- 0.30 mmol/L, mean +/- SE; p < 0.05) and hepatic cholesterol (70.3 +/- 4.3 mg/g vs. 54.3 +/- 3.8 mg/g, mean +/- SD; p < 0.05) were significantly lowered compared to those of the control. HMG-CoA reductase (2487.0 +/- 210.0 pmole/min/mg vs. 1879.0 +/- 236.0 pmole/min/mg, mean +/- SE; p < 0.05) and ACAT (806.0 +/- 105.0 pmole/min/mg vs. 643.0 +/- 80.0 pmole/min/mg, mean +/- SE; p < 0.05) activities were both substantially lower in the naringin-supplemented group than in the control. The naringin supplementation markedly decreased the excretion of fecal neutral sterols (204.7 +/- 28.5 mg/day) compared to the control (521.9 +/- 53.9 mg/day). The combination of the inhibited HMG-CoA reductase (-24.4%) and ACAT (-20.2%) activities as a result of naringin supplementation could account for the decrease of fecal neutral sterols.

Actinomycin D as a novel SH2 domain ligand inhibits Shc/Grb2 interaction in B104-1-1 (neu*-transformed NIH3T3) and SAA (hEGFR-overexpressed NIH3T3) cells

Actinomycins, a family of bicyclic chromopeptide lactones with strong antineoplastic activity, were screened as inhibitors of Shc/Grb2 interaction in in vitro assay systems. To investigate the effects of actinomycin D on Shc/Grb2 interaction in cell-based experiments, we used SAA (normal hEGFR-overexpressed NIH3T3) cells and B104-1-1 (neu*-transformed NIH3T3) cells, because a large number of the Shc/Grb2 complexes were detected. Associated protein complexes containing Shc were immunoprecipitated from actinomycin D-treated cell lysates with polyclonal anti-Shc antibody. Then the association with Grb2 was assessed by immunoblotting with monoclonal anti-Grb2 antibody. The result of the immunoblotting experiment revealed that actinomycin D inhibited Shc/Grb2 interaction in a dose-dependent manner in both B104-1-1 and EGF-stimulated SAA cells. The inhibition of Shc/Grb2 interaction by actinomycin D in B104-1-1 cells also reduced tyrosine phosphorylation of MAP kinase (Erk1/Erk2), one of the major components in the Ras-MAP kinase signaling pathway. These results suggest that actinomycin D could be a non-phosphorylated natural and cellular membrane-permeable SH2 domain antagonist.

Plasma and hepatic cholesterol and hepatic activities of 3-hydroxy-3-methyl-glutaryl-CoA reductase and acyl CoA: cholesterol transferase are lower in rats fed citrus peel extract or a mixture of citrus bioflavonoids

The cholesterol-lowering effects of tangerine peel extract and a mixture of two citrus flavonoids were tested. Male rats were fed a 1 g/100 g high-cholesterol diet for 42 d with supplements of either tangerine-peel extract or a mixture of naringin and hesperidin (0.5 g/100 g) to study the effects of plasma and hepatic lipids, hepatic enzyme activities, and the excretion of fecal neutral sterols. Both the tangerine-peel extract and mixture of two flavonoids significantly lowered the levels (mean +/- SE) of plasma (2.44 +/- 0. 59 and 2.42 +/- 0.31 mmol/L, vs. 3.80 +/- 0.28 mmol/L, P < 0.05), hepatic cholesterol (0.143 +/- 0.017 and 0.131 +/- 0.010 mmol/g vs. 0.181 +/- 0.003 mmol/g, P < 0.05), and hepatic triglycerides (0.069 +/- 0.007 and 0.075 +/- 0.006 mmol/g vs. 0.095 +/- 0.002 mmol/g, P < 0.05) compared to those of the control. The 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase (1565.0 +/- 106. 0 pmol. min-1. mg protein-1 and 1783.0 +/- 282 pmol. min-1. mg protein-1 vs. 2487.0 +/- 210.0 pmol. min-1. mg protein-1, P < 0.05) and acyl CoA: cholesterol O-acyltransferase (ACAT) activities (548.0 +/- 65.0 and 615.0 +/- 80.0 pmol. min-1. mg protein-1 vs. 806.0 +/- 105.0 pmol. min-1. mg protein-1, P < 0.05) were significantly lower in the experimental groups than in the control. These supplements also substantially reduced the excretion of fecal neutral sterols compared to the control (211.1 +/- 26.7 and 208.2 +/- 31.6 mg/d vs. 521.9 +/- 53.9 mg/d). The inhibition of HMG-CoA reductase and ACAT activities resulting from the supplementation of either tangerine-peel extract or a combination of its bioflavonoids could account for the decrease in fecal neutral sterol that appears to compensate for the decreased cholesterol biosynthesis in the liver.

Inhibitory effect of triterpenes from Crataegus pinatifida on HIV-I protease

The methanol extracts of the leaves of Crataegus pinnatifida showed potent inhibitory activities against HIV-1 protease at a concentration of 100 micrograms/ml. The subsequent fractionation and isolation of the extract gave two active compounds. Their structures were identified as uvaol (1) and ursolic acid (2) by spectral data. These active compounds inhibit HIV-1 protease with IC50 values of 5.5 and 8.0 microM, respectively.

Chitin synthase II inhibitory activity of ursolic acid, isolated from Crataegus pinnatifida

Two triterpenoid compounds, ursolic acid and uvaol, were isolated from Crataegus pinnatifida Bunge leaves. Ursolic acid inhibits chitin synthase II from S. cerevisiae with an IC50 value of 0.84 microgram/ml and the inhibition appears to be selective for chitin synthase II, whereas uvaol has no inhibitory activity up to 280 micrograms/ml. Oleanolic acid, alpha-hederin hydrate, and betulic acid inhibited the chitin synthase II activity under the same conditions with an IC50 of 5.6, 64.3, and 98.7 micrograms/ml, respectively.

Inhibition of chitin synthase II by catechins from stem bark of Taxus cuspidata

Two flavonoids, (+/-)-catechin and (-)-epicatechin, were isolated from the stem bark of Taxus cuspidata by monitoring chitin synthase II inhibitory activity. The compounds inhibit chitin synthase II with an IC50 of 15 and 29 micrograms/ml, respectively and appear to be selective for chitin synthase II. They did not inhibit chitin synthase III.

Acyl-CoA:Cholesterol Acyltransferase Inhibitory Activity of Lignans Isolated from Schizandra, Machilus and Magnolia Species

Fifteen lignans were isolated from the fruits of SCHIZANDRA CHINENSIS, the leaves of MACHILUS THUNBERGII, and the flower buds of MAGNOLIA DENUDATA. They were identified as gomisins, schizandrin, wuweizisu, schizantherin, licarins, and machilin, which inhibited rat liver ACAT with IC (50) values of 25-200 microM. Comisin N is the most potent inhibitor with IC (50) value of 25 microM in these lignans.

Actinomycin D, C2 and VII, inhibitors of Grb2-SHC interaction produced by Streptomyces

Actinomycin D, C2 and VII, cyclic peptides, inhibited Grb2 SH2 domain association (IC50 5-7 microM) with a phosphotyrosine containing peptide derived from the Shc protein (pTyr317). Actinomycins are the first examples of nonphosphorylated natural ligands of SH2 domain.

Differentially expressed aortic genes in cholesterol-fed rabbits

In order to identify key genes involved in the development of atherosclerotic lesions, differentially expressed genes in atherosclerotic plaques obtained from diet-induced hypercholesterolemic rabbit aorta were screened using the differential display (DD) RT-PCR technique. Aortic RNAs were isolated from rabbits fed cholesterol-supplemented (2% cholesterol in lab-chow, w/w) chow diet for 12 weeks, followed by the synthesis of cDNAs by reverse-transcription using 2-base anchored oligo (dT) (5'-T11VN) as 3'-primers. Synthesized cDNAs were amplified by PCR using arbitrary 10-mers as 5'-primers and the same 3'-primers used in the reverse-transcription. Amplified cDNAs sized between 0.2 to 0.5kb obtained from control and cholesterol-fed rabbit aortas were displayed on the 6% DNA-sequencing gel for comparisons. The cDNA bands showing distinctive differences in patterns of display or in density of the band were extracted from the gel. A total of 66 differentially displayed cDNAs was isolated and subjected to the reverse-Northern and Northern blot analyses in order to confirm the differences. Through the extensive confirming processes, three cDNAs were finally selected (designated CRGRA-1 through -3) and their nucleotide sequences were determined. Two of those (CRGRA-1 and -2) were determined to be up regulated and the other (CRGRA-3) was down-regulated by the cholesterol-feeding. Upon homology search on databases for the identification of the genes, the first cDNA (CRGRA-1) turned out to be a part of a novel gene, the second one (CRGRA-2) was homologous (82%) to the corresponding segment of mitochondrial NADH dehydrogenase subunits 4 gene, and the last one (CRGRA-2) was identified to be homologous (94%) to a segment of human small GTP-binding protein (Rab7) gene.

A glycine-rich RNA-binding protein gene is differentially expressed during acute hypersensitive response following Tobacco Mosaic Virus infection in tobacco

During efforts for cloning disease resistance-responsive genes, a cDNA encoding a putative Nicotiana glutinosa glycine-rich RNA binding protein (ngRBP) was isolated from TMV induced cDNA library. Northern blot hybridization revealed that ngRBP gene is negatively regulated during early hours of TMV induced acute hypersensitive response (HR). Under greenhouse conditions induced expression of ngRBP gene was observed after 24 h following TMV infection. Salicylic acid and copper also induced ngRBP mRNA expression. Our findings are suggestive of some possible role for ngRBP in plant-pathogen interaction.

Synthesis and in vitro cytotoxicity of cinnamaldehydes to human solid tumor cells

Cinnamaldehydes and related compounds were synthesized from various cinnamic acids based on the 2'-hydroxycinnamaldehyde isolated from the bark of Cinnamomum cassia Blume. The cytotoxicity to human solid tumor cells such as A549, SK-OV-3, SK-MEL-2, XF498 and HCT15 were measured. Cinnamic acid, cinnamates and cinnamyl alcohols did not show any cytotoxicity against the human tumor cells. Cinnamaldehydes and related compounds were resistant to A549 cell line up to 15 micrograms/ml. In contrast, HCT15 and SK-MEL-2 cells were much sensitive to these cinnamaldehyde analogues which showed ED50 values 0.63-8.1 micrograms/ml. Cytotoxicity of the saturated aldehydes was much weak compared to their unsaturated aldehydes. From these studies, it was found that the key functional group of the cinnamaldehyde-related compounds in the antitumor activity is the propenal group.

Polyacetylene analogs, isolated from hairy roots of Panax ginseng, inhibit Acyl-CoA : cholesterol acyltransferase

In the course of our screening program for acyl-CoA : cholesterol acyltransferase (ACAT) inhibitors from Korean herbal medicines, ACAT inhibitors were isolated from the hairy roots of Panax ginseng (Araliaceae) and identified as panaxynol, panaxydol, panaxydiol, and panaxytriol. These active compounds inhibit rat liver ACAT with IC50 values of 94, 80, 45 and 79 microM, respectively.

Acyl-CoA : cholesterol acyltransferase inhibitors from Magnolia obovata

In the course of a search for acyl-CoA : cholesterol acyltransferase (ACAT) inhibitors from natural sources, new types of ACAT inhibitors were isolated from the extract of Magnolia obovata leaves, and identified as obovatol, honokiol, and magnolol. The active compounds inhibit rat liver ACAT with IC50 values of 42, 71, and 86 microM, respectively.

Characterization ofBacillus thuringiensismutants and natural isolates by molecular methods

Two Bacillus thuringiensis var. kurstaki HD-1 mutants, two Bacillus thuringiensis var. israelensis HD-500 mutants, and four rice grain dust isolates were characterized using microscopic examination and protein profiles of purified crystals on sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Specific detection of cryI- and cryIV-type genes was performed in a polymerase chain reaction using cryI and cryIV-specific oligonucleotide primers. The cry-type genes under study consisted of cryIA(a), cryI(A)b, cryI(A)c, cryIB, and cryIV. Presence or absence of the cryI- and cryIV-type genes was further confirmed by Southern blotting followed by hybridization with specific cryI and cryIV gene fragments. A genetically modified strain of B. thuringiensis var. kurstaki HD-1, called OZK-13 and obtained following mutagenesis with ozone, was shown to contain cryIA(a), cryIA(b), and cryIA(c) genes. Another kurstaki HD-1 mutant, called NGK-13 and obtained following treatment with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), was shown to have lost the cryIA(b) gene while retaining the cryIA(a) and cryIA(c) genes. NGI-23-1, an oligosporogenous–multicrystalliferous mutant of B. thuringiensis var. israelensis (Bti) HD-500, obtained following treatment with MNNG contained cryIV-type genes. NGI-22, an oligosporogenous–acrystalliferous mutant of Bti HD-500, contained no cryI- nor cryIV-type genes. The rice grain dust isolate BT-285 contained the cryIA(a) and cryIA(c) genes. Isolate BT-14 contained only the cryIA(c) gene, whereas isolate BT-209 contained cryIA(a), cryIA(b), and cryIB genes. Isolate BT-205 contained no cryI- nor cryIV-type genes. Bacillus thuringiensis mutants and natural isolates shown to contain cryI-type genes were tested for their insecticidal activities in a series of bioassays against Hyphantria cunea Drury (Lepidoptera: Arctiidae). All cryI-carrying strains were toxic against the insect larvae. BT-205 was also tested and exhibited no toxicity against the insect larvae.Key words: Bacillus thuringiensis, δ-endotoxin crystal, cry-type genes, polymerase chain reaction.

Molecular cloning of a metallothionein-like gene from Nicotiana glutinosa L. and its induction by wounding and tobacco mosaic virus infection

The cloning and characterization of genes expressed in plant disease resistance could be an initial step toward understanding the molecular mechanisms of disease resistance. A metallothionein-like gene that is inducible by tobacco mosaic virus and by wounding was cloned in the process of subtractive cloning of disease resistance-response genes in Nicotiana glutinosa. One 530-bp cDNA clone (KC9-10) containing an open reading frame of 81 amino acids was characterized. Genomic Southern blot hybridization with the cDNA probe revealed that tobacco metallothionein-like genes are present in few or in one copy per diploid genome. Northern blot hybridization detected strong induction of a 0.5-kb mRNA by wounding and tobacco mosaic virus infection, but only mild induction was detected when copper was tested as an inducer. Methyl jasmonate, salicylic acid, and ethylene were also tested as possible inducers of this gene, but they had no effect on its expression. The possible role of this gene in wounded and pathogen-stressed plants is discussed.

2'-Hydroxycinnamaldehyde from stem bark of Cinnamomum cassia

2'-Hydroxycinnamaldehyde, which inhibits farnesyl-protein transferase (FPTase), has been isolated from the stem bark of Cinnamomum cassia Blume. The biologically active agent in the extract has been purified by silica column chromatography and HPLC. The structure of the isolated compound was elucidated on the basis of 500 MHz NMR experiments.

Isolation of cholesteryl ester transfer protein inhibitors from Panax ginseng roots

We have isolated cholesteryl ester transfer protein (CETP) inhibitors from the extract of Korean Panax ginseng C. A. Meyer roots and identified them as polyacetylene analogs. These compounds inhibit human CETP with IC50 values of around 20-35 mg/ml.

GERI-BP002-A, novel inhibitor of acyl-CoA: cholesterol acyltransferase produced by Aspergillus fumigatus F93

A new inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), designated GERI-BP002-A, was isolated from the culture broth of Aspergillus fumigatus F93 by acetone extraction, EtOAc extraction, SiO2 column chromatography and reverse phase HPLC. Spectroscopic analyses of the compound identified bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane as the structure and its molecular weight and formula to be 340 and C23H32O2, respectively. GERI-BP002-A inhibited ACAT activity by 50% at the concentration of 50 microM in an enzyme assay system using rat liver microsomes.

GERI-BP001 compounds, new inhibitors of acyl-CoA: cholesterol acyltransferase from Aspergillus fumigatus F37. I. Production, isolation, and physico-chemical and biological properties

GERI-BP001 compounds, new inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT), were isolated from a culture broth of Aspergillus fumigatus F37 by acetone extraction, EtOAc extraction, SiO2 column chromatography, and reverse phase HPLC. GERI-BP001 M, A, and B inhibit ACAT activity in an enzyme assay system using rat liver microsomes by 50% at concentrations of 42, 94, and 40 microM, respectively.

Computer-Aided Design and Computer-Aided Manufacture (CAD-CAM) applications in cosmetic below-elbow prostheses

Computer-Aided Design and Computer-Aided Manufacture (CAD/CAM) techniques, though often technologically associated with engineering and applied sciences, has opened new horizons in the medical field. In CAD, a product is first geometrically modelled in three dimensions in a computer and it can be viewed and examined from any direction. This model can then be used for many downstream applications such as manufacturing and analysis. In CAM, numerically controlled machining processes are used for cutting out a prosthetic device of the hand for prosthesis. The paper aims at establishing the basis of using CAD/CAM techniques in prostheses in particular, a review of our present work done in the area of below-elbow prostheses using CAD/CAM. A laser scanning device has been used to capture the geometry of human hands. The algorithm used in processing the images is discussed. The processed 3D data file is then interfaced with a CAD modeller where reconstruction, mirroring, scaling, etc., can be performed. The resultant CAD model is then passed on to CAM, which concentrates purely on producing a "positive core" mould for moulding the prosthetic device.

New microbial growth factor

A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a new microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight, and it has high specific activity. When added to the diets for a meadow vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.