Hypoglycemic property of soy isoflavones from hypocotyl in Goto-Kakizaki diabetic rats.

The present study was carried out to investigate the hypoglycemic effect of soy isoflavones from hypocotyl in GK diabetic rats. A single administration and long-term administration tests were conducted in GK diabetic rats to test the hypoglycemic effect of soy isoflavones. At the end of long-term administration trial, blood protein, cholesterol, triglyceride, glycosylated serum protein, C-reactive protein, insulin, aminotransferase, lipid peroxide, interleukin-6, tumor necrosis factor-α were estimated. Inhibition of soy isoflavones against α-amylase and α-glucosidase, as well as on glucose uptake into brush border membrane vesicles or Caco-2 cells were determined in vitro. In single administration experiment, soy isoflavones reduced postprandial blood glucose levels in GK rats. In long-term administration, hypoglycemic effect of soy isoflavones was first observed at week 12 and maintained till week 16. A significant reduction in fasting blood glucose, C-reactive protein, and lipid peroxide was noted at week 16. However, there was no significant treatment effect on blood insulin. Furthermore, soy isoflavone administration resulted in significant decreases in glycosylated serum protein, tumor necrosis factor-α, and interleukin-6. Other biochemical parameters, such as protein, cholesterol, triglyceride and aminotransferases were not modified, however. The results in vitro showed that soy isoflavones showed a potent inhibitory effect on intestinal α-glucosidase, but not on pancreatic α-amylase. Soy isoflavones also decreased glucose transport potency into brush border membrane vesicles or Caco-2 cells. It is concluded that soy isoflavones from hypocotyl, performs hypoglycemic function in GK rats with type 2 diabetes, maybe via suppression of carbohydrate digestion and glucose uptake in small intestine.

[Rhaponticum uniflorum inhibits H2O2-induced apoptosis of liver cells via JNK and NF-κB pathways].

To study the inhibitory effect of Rhaponticum uniflorum on apoptosis induced by H2O2 in HepG2 cells. Human HepG2 cells injury models were established by H2O2, then cell survival rate was assayed by MTT method; levels of LDH, ALT, and AST were detected by chemical colorimetric method;SOD activity was detected by xanthine oxidase method; GSH content was detected by dithio-bis-nitrobenzoic acid(DTNB); MDA level was detected by thiobarbituric acid (TBA) method;and the relative activities of Caspase-3, 8 and 9 were measured by Colorimetry. The expression levels of Cleaved Caspase-3(Casp-3), cytochrome(Cyto c), NF-κB, ERK, JNK, p38 MAPK, as well as the phospharylated proteins were determined with Western blotting method. The results showed that R. unifloru had no significant effect on cell viabilities of HepG2 cells at the concentrations of 25-400 mg•L⁻¹. However, H2O2decreased the cell viabilities, increased the cellular oxidative stress, and up-regulated the protein expressions of Casp-3, cytoplasmic Cyto c, p-JNK and nuclear NF-κB. As compared with the model group,R. unifloru could increase the cell viability, reduce LDH, ALT and AST leakage, reduce the MDA formation, increase the SOD and GSH levels,reduce the relative activities of Caspase-3, 8 and 9, down-regulated the protein expressions of Casp-3 and cytoplasmic Cyto c, and down-regulate the p-JNK and nuclear NF-κB levels.The results indicated that R. unifloru had the inhibitory effect on apoptosis induced by H2O2in HepG2 cells, and the mechanism maybe associated with inhibiting JNK activation and NF-κB nuclear translocation.

[Protective effect of soyasaponins on acute liver injury induced by D-galactosamine and lipopolysaccharide in mice].

OBJECTIVE: To investigate the protective effect of soyasaponins on acute liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in mice. METHOD: The mice were randomly divided into five groups: the normal control, the model group, the silymarin (positive control) group, and soyasaponins high and low-dose groups. They were administered with drugs once every day for 7 days. At the end of the experiment, GalN and LPS were injected intraperitoneally to all of the groups except for the normal group to establish the acute liver injury model. The pathological changes were detected with hematoxylin & eosin (HE) staining, tumor necrosis factor-alpha (TNF-alpha) was detected by ELISA method, and the alanine aminotransferase (ALT), aspartate aminotransferase (AST), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), reduced glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), and the activation of Caspase-3 and Caspase-8 were detected by the colorimetric method. RESULT: Soyasaponins could reduce the activities of serum ALT and AST, the acute hepatic injury induced by GalN/LPS, serum TNF-alpha level, hepatic NO and MDA contents, and the Caspase-3 and Caspase-8 activations of liver tissues, and increase the hepatic CAT, GPx, GST and GSH levels. CONCLUSION: Soyasaponins shows the protective effect on acute liver injury induced by GalN and LPS in mice, which may be related to its antioxidative ability and anti-liver apoptosis.

[Intervention effect of aqueous fractions from Boschniakia rossica on hepatic oxidative stress in mice with liver injury induced by carbon tetrachloride].

OBJECTIVE: To investigate the intervention effect of aqueous fractions from Boschniakia rossica (BRAF) on hepatic oxidative stress in mice with liver injury induced by carbon tetrachloride (CCl4). METHOD: The experimental mice were randomly assigned into the normal control group, the model group, the silymarin (positive control) group, as well as high and low dose BRAF groups. Mice were treated intragastrically with silymarin or BRAF once every day for 7 days. At the end of the experiment, CCl4 was injected intraperitoneally into the mice to establish the acute liver injury model. The pathological changes was detected with hematoxylin and eosin (HE) staining, and the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), superoxide dismutase (SOD) , catalase (CAT), glutathione peroxidase (GPx), Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, and the contents of reduced glutathione (GSH) and malondialdehyde (MDA) were detected by the colorimetric method. RESULT: BRAF significantly reduced ALT, AST and ALP activities in serum, alleviated hepatic injury induced by CCl4, increased SOD, CAT, GPx and GSH levels in liver, and SOD, Na + -K + -ATPase and Ca2+ -Mg2 + -ATPase activities in liver mitochondria, and decreased the MDA content in liver and liver mitochondria. CONCLUSION: BRAF reduces hepatic oxidative stress in mice with acute liver injury induced by CCl4, thereby showing the protective effect on mice with acute liver injury induced by CCl4.

[Anti-atherosclerotic effect of soybean isofalvones and soyasaponins in diabetic rats].

OBJECTIVE: To study the influence of soybean phytochemical extract containing isoflavones and soyasaponins (SPE) on blood glucose, blood lipids, plasma lipid peroxide and platelet aggregation activity in diabetic rats. METHODS: Diabetic rats were fed with fodder containing 20 g/kg of SPE for 20 weeks. Their plasma very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) were separated by sequential ultracentrifugation. RESULTS: Twenty weeks after experiment, level of blood glucose, atherosclerotic index and plasma level of lipid peroxide were (11.9 +/- 0.9) mmol/L, 0.40 +/- 0.14 and (15.7 +/- 0.5) mmol/L, respectively in diabetic rats fed with SPE, significantly lower than those in control rats not fed with it, (14.2 +/- 2.0) mmol/L, 0.58 +/- 0.22 and (20.7 +/- 3.0) mmol/L, respectively. Accordingly, platelet aggregation rates induced by ADP and collagen in the two groups were (54.1 +/- 8.8)% vs (66.6 +/- 12.4)% and (58.0 +/- 7.9)% vs (69.6 +/- 9.4)%, respectively. Changes in all these indices were significantly different between the two groups. CONCLUSION: SPE could significantly decrease blood glucose, improve atherosclerotic index, and inhibit lipid peroxidation and platelet aggregation in diabetic rats, which might be useful in prevention and control of diabetes mellitus and diabetes-associated atherosclerosis.

Effect of Boschniakia rossica on expression of GST-P, p53 and p21(ras)proteins in early stage of chemical hepatocarcinogenesis and its anti-inflammatory activities in rats.

AIM:To investigate the effect of Boschniakia rossica (BR) extract on expression of GST-P, p53 and p21(ras) proteins in early stage of chemical hepatocarcinogenesis in rats and its anti-inflammatory activities.METHODS:The expression of tumor marker-placental form glutathione S-transferase (GST-P), p53 and p21(ras) proteins were investigated by immunohisto-chemical techniques and ABC method. Anti-inflammatory activities of BR were studied by xylene and croton oil-induced mouse ear edema, carrageenin, histamine and hot scald-induced rat pow edema, adjuvant-induced rat arthritis and cotton pellet induced mouse granuloma formation methods.RESULTS:The 500mg/kg of BR-H2O extract frac-tionated from BR-Methanol extract had inhibitory effect on the formation of DEN-induced GST-P-positive foci in rat liver (GST-P staining was 78% positive in DEN+AAF group vs 20% positive in DEN+AAF+BR group, P<0.05) and the expression of mutant p53 and p21(ras) protein was lower than that of hepatic preneoplastic lesions (33% and 22% positive respectively in DEN+AAF group vs negative in DEN+AAF+BR group). Both CH(2)Cl(2) and H(2)O extracts from BR had anti-inflamatory effect in xylene and crotonoil induced mouse ear edema (inhibitory rates were 26%-29% and 35%-59%, respectively). BR H(2)O extract exhibited inhibitory effect in carrageenin, histamine and hot scald-induced hind paw edema and adjuvant-induced arthritis in rats and cotton pellet-induced granuloma formation in mice.CONCLUSION:BR extract exhibited inhibitory effect on formation of preneoplastic hepatic foci in early stage of rat chemical hepato-carcinogenesis.Both CH(2)Cl(2) and H(2)O extracts from BR exerted anti-inflammatory effect in rats and mice.