Effect of layer thickness and printing orientation on the color stability and stainability of a 3D-printed resin material.

STATEMENT OF PROBLEM: Although 3-dimensional (3D)-printed resin prostheses are widely used, studies on the effects of the manufacturing parameters of 3D printing on the color stability and stainability of these prostheses are lacking. PURPOSE: The purpose of this in vitro study was to investigate the effects of layer thickness and printing orientation on the color stability and stainability of a 3D-printed resin. In addition, the influence of roughness and water contact angle was evaluated. MATERIAL AND METHODS: Color changes (ΔE00) in tooth-colored resin specimens produced by 3D printing with 2 different layer thicknesses and 3 different printing orientations and immersed in 3 types of aging media (distilled water, coffee solution, and wine) were evaluated (n=10). The CIELab color values were measured with a spectrophotometer at baseline and different time points (1, 3, 7, 15, and 30 days). The surface roughness (Ra) of resin specimens was measured at various time points (baseline, 7, 15, and 30 days) by confocal laser scanning microscopy after immersion in coffee solution (n=15). The water contact angle was determined by using the sessile drop method (n=10). The ΔE00 values were analyzed by using the 3-way repeated measures ANOVA followed by the Bonferroni test and Dunnett T3 test (α=.05). Ra values were analyzed by 3-way repeated measures ANOVA (α=.05). The water contact angle data were analyzed by 2-way ANOVA (α=.05). RESULTS: The 3-way repeated measures ANOVA showed that layer thickness, printing orientation, and storage time significantly influenced the ΔE00 values of the 3D-printed resin specimens in each aging medium (P<.001). The ΔE00 values in the 0-degree subgroups were significantly lower than those in the 45- and 90-degree subgroups (P<.05). The ΔE00 values in the 25-µm thick groups were significantly higher than those in the 100-µm thick groups (P<.05). The ΔE00 values demonstrated an increase up to 15 days in all aging media. In distilled water, the ΔE00 values of the specimens increased or decreased depending on the groups, whereas in the coffee solution, the values decreased after 15 days (P<.001); in red wine, the values demonstrated a continuous increase up to 30 days in all groups (P<.001). The 3-way repeated measures ANOVA showed that the Ra values did not change significantly with immersion time (P=.444). The 2-way ANOVA showed that the water contact angle was not significantly affected by layer thickness (P=.921) or printing orientation (P=.062). CONCLUSIONS: Layer thickness and printing orientation affected the color stability and stainability of the 3D-printed resin. The discoloration of the 3D-printed resin differed with time, depending on the type of aging media used.

Effect of post-curing time on the color stability and related properties of a tooth-colored 3D-printed resin material.

This study investigated the effect of post-curing time on the color stability and related properties, such as degree of conversion (DC), surface roughness, water contact angle, water sorption (Wsp), and water solubility (Wsl) of 3D-printed resin for dental restorations. The 3D-printed specimens were divided into four groups according to the post-curing time (0, 5, 10, and 20 min). Color changes (ΔE00) of the specimens immersed in aging media were measured using a spectrophotometer at different aging times. The DC of the resin was measured using a FTIR. The surface roughness (Ra) of the resin immersed in coffee was measured at different aging times. Water contact angle was evaluated using the sessile drop method, and Wsp and Wsl were tested according to the ISO 4049:2019. The ΔE00 values of the specimens immersed in coffee and red wine decreased with increasing post-curing time. As the post-curing time increased up to 10 min, the DC increased and water contact angle decreased. The Ra value of the group without post-curing (0 min) increased gradually for 30 days, except between 7 and 15 days. However, when the post-curing time increased to greater than 10 min, no apparent change in Ra value was detected. The Wsp and Wsl of the group without post-curing were significantly lower and larger than that of the other groups, respectively. The longer the post-curing time of the tooth-colored 3D-printed resin, the better the color stability. The post-curing time of the 3D-printed resin affected the DC, surface roughness after aging in the staining media, water contact angle, water sorption, and water solubility.

Methoxsalen supplementation attenuates bone loss and inflammatory response in ovariectomized mice.

Methoxsalen (MTS) is a natural bioactive compound found in a variety of plants that has many known biofunctions; however, its effects on osteoporosis and related mechanisms are not clear. This study examined whether MTS exhibited preventive effects against postmenopausal osteoporosis. Female C3H/HeN mice were divided into four groups: Sham, ovariectomy (OVX), OVX with MTS (0.02% in diet), and OVX with estradiol (0.03 µg/day, s.c). After 6 weeks, MTS supplementation significantly increased femur bone mineral density and bone surface along with bone surface/total volume. MTS significantly elevated the levels of serum formation markers (estradiol, osteocalcin and bone-alkaline phosphatase) such as estradiol in OVX mice. Tartrate resistant acid phosphatase staining revealed that MTS suppressed osteoclast numbers and formation in femur tissues compared with the OVX group. Supplementation of MTS slightly up-regulated osteoblastogenesis-related genes (Runx-2, osterix, osteocalcin, and Alp) expression, whereas it significantly down-regulated inflammatory genes (Nfκb and Il6) expression in femur tissue compared with the OVX group. These results indicate that MTS supplementation effectively prevented OVX-induced osteoporosis via enhancement of bone formation and suppression of inflammatory response in OVX mice. Our study provides valid scientific information regarding the development and application of MTS as a food ingredient, a food supplement or an alternative agent for preventing postmenopausal osteoporosis.

Scopoletin Supplementation Ameliorates Steatosis and Inflammation in Diabetic Mice.

Scopoletin is a bioactive component in many edible plants and fruits. This study investigated the effects of scopoletin on hepatic steatosis and inflammation in a high-fat diet fed type 1 diabetic mice by comparison with metformin. Scopoletin (0.01%, w/w) or metformin (0.5%, w/w) was provided with a high-fat diet to streptozotocin-induced diabetic mice for 11 weeks. Both scopoletin and metformin lowered blood glucose and HbA1c , serum ALT, TNF-α and IL-6 levels, glucose intolerance, and hepatic lipid accumulation compared with the diabetic control group. Scopoletin or metformin down-regulated hepatic gene expression of triglyceride (Pparg, Plpp2, and Dgat2) and cholesterol (Hmgcr) synthesis as well as inflammation (Tlr4, Myd88, Nfkb1, Tnfa, and Il6), while it up-regulated Cyp7a1 gene. Hepatic PPARγ and DGAT2 protein levels were also down-regulated in scopoletin or metformin group compared with the control group. Scopoletin or metformin also inhibited hepatic fatty acid synthase and phosphatidate phosphohydrolase activities. These results suggest that scopoletin protects against diabetes-induced steatosis and inflammation by inhibiting lipid biosynthesis and TLR4-MyD88 pathways. Copyright © 2017 John Wiley & Sons, Ltd.

Anti-adipogenic and anti-diabetic effects of cis-3',4'-diisovalerylkhellactone isolated from Peucedanum japonicum Thunb leaves in vitro.

Peucedanum japonicum Thunb is a medicinal plant belonging to the family Umbelliferae. This study evaluated the anti-diabetic and anti-obesity effects of cis-3',4'-diisovalerylkhellactone (cDIVK) isolated from Peucedanum japonicum Thunb leaves. cDIVK (30 and 50µM) effectively inhibited adipocyte differentiation and fat accumulation, whereas it stimulated glucose uptake compared with the control in 3T3-L1 cells. cDIVK significantly increased AMPK activation and suppressed protein and mRNA expression of major adipogenic transcriptional factors such as C/EBPα, PPARγ and SREBP-1c in 3T3-L1 cells. In addition, cDIVK had potential α-glucosidase inhibitory activity. These results indicated that cDIVK may act as a natural dual therapeutic agent for diabetes and obesity.

Dietary umbelliferone attenuates alcohol-induced fatty liver via regulation of PPARα and SREBP-1c in rats.

This study investigated the effects of umbelliferone (UF) on alcoholic fatty liver and its underlying mechanism. Rats were fed a Lieber-DeCarli liquid diet with 36% of calories as alcohol with or without UF (0.05 g/L) for 8 weeks. Pair-fed rats received an isocaloric carbohydrate liquid diet. UF significantly reduced the severity of alcohol-induced body weight loss, hepatic lipid accumulation and droplet formation, and dyslipidemia. UF decreased plasma AST, ALT, and γGTP activity. UF significantly reduced hepatic cytochrome P450 2E1 activities and increased alcohol dehydrogenase and aldehyde dehydrogenase 2 activities compared to the alcohol control group, which resulted in a lower plasma acetaldehyde level in the rats that received UF. Chronic alcohol exposure inhibited hepatic AMPK activation compared to the pair-fed rats, which was reversed by UF supplementation. UF also significantly suppressed the lipogenic gene expression (SREBP-1c, SREBP-2, FAS, CIDEA, and PPARγ) and elevated the fatty acid oxidation gene expression (PPARα, Acsl1, CPT, Acox, and Acaa1a) compared to the alcohol control group, which could lead to inhibition of FAS activity and stimulation of CPT and fatty acid ß-oxidation activities in the liver of chronic alcohol-fed rats. These results indicated that UF attenuated alcoholic steatosis through down-regulation of SREBP-1c-mediated lipogenesis and up-regulation of PPARα-mediated fatty acid oxidation. Therefore, UF may provide a promising natural therapeutic strategy against alcoholic fatty liver.

Effects of ursolic acid on glucose metabolism, the polyol pathway and dyslipidemia in non-obese type 2 diabetic mice.

Ursolic acid (UA) is a pentacyclic triterpenoid compound that naturally occurs in fruits, leaves and flowers of medicinal herbs. This study investigated the dose-response efficacy of UA (0.01 and 0.05%) on glucose metabolism, the polyol pathway and dyslipidemia in streptozotocin/nicotinamide-induced diabetic mice. Supplement with both UA doses reduced fasting blood glucose and plasma triglyceride levels in non-obese type 2 diabetic mice. High-dose UA significantly lowered plasma free fatty acid, total cholesterol and VLDL-cholesterol levels compared with the diabetic control mice, while LDL-cholesterol levels were reduced with both doses. UA supplement effectively decreased hepatic glucose-6-phosphatase activity and increased glucokinase activity, the glucokinase/glucose-6-phosphatase ratio, GLUT2 mRNA levels and glycogen content compared with the diabetic control mice. UA supplement attenuated hyperglycemia-induced renal hypertrophy and histological changes. Renal aldose reductase activity was higher, whereas sorbitol dehydrogenase activity was lower in the diabetic control group than in the non-diabetic group. However, UA supplement reversed the biochemical changes in polyol pathway to normal values. These results demonstrated that low-dose UA had preventive potency for diabetic renal complications, which could be mediated by changes in hepatic glucose metabolism and the renal polyol pathway. High-dose UA was more effective anti-dyslipidemia therapy in non-obese type 2 diabetic mice.

Platycodi radix saponin inhibits α-glucosidase in vitro and modulates hepatic glucose-regulating enzyme activities in C57BL/KsJ-db/db mice.

This study investigated anti-diabetic activity of a concentrated saponin fraction from Platycodi radix (SK1) in C57BL/KsJ-db/db mice and its underlying mechanism. Mice were fed diet with 0.5 % SK1 (w/w) for 6 weeks. SK1 significantly lowered the blood glucose and glycosylated hemoglobin levels and improved glucose and insulin tolerance. The plasma and pancreatic insulin and C-peptide levels and fecal cholesterol content were increased, whereas plasma urea nitrogen, free fatty acid and triglyceride levels were decreased by SK1 supplementation. Glucokinase (GK) activity in the liver was significantly higher in the SK1 group than the control group, whereas the glucose-6-phosphatase (G6Pase) activity was lower. SK1 significantly down-regulated GK mRNA expression compared to the control group but did not affect G6Pase and glucose transporter 2 mRNA. Phosphoenolpyruvate carboxykinase activity and mRNA levels did not differ between groups. SK1 also markedly inhibited the small intestinal disaccharidases activities compared to those of control db/db mice. Furthermore, SK1 was a more effective α-glucosidase inhibitor than acarbose in vitro. Overall, these findings suggest that SK1 is a potential glucose-lowering agent that functions via inhibition of carbohydrate digestive enzyme activities and modulation of glucose-regulating enzyme activities in db/db mice.

Effects of intravesical electrical stimulation therapy on urodynamic patterns for children with spina bifida: a 10-year experience.

OBJECTIVE: Intravesical electrical stimulation (IVES) has been performed for various purposes in children with a neurogenic bladder. We evaluated the results of IVES on urodynamic study parameters in children with spina bifida. METHODS: We retrospectively analyzed the cases of 88 children who received IVES between August 1999 and May 2010 and whose comparative urodynamic data were available before and after treatment. According to the pre-IVES urodynamic study, children were divided into 3 groups: detrusor overactivity, detrusor underactivity and acontractile detrusor. We investigated the changes in detrusor function, bladder capacity and detrusor-sphincter dyssynergia. RESULTS: In the group showing detrusor overactivity, the bladder had a synergic pattern in 41.7%, and normal detrusor function was observed in 16.7% of them. Bladder capacity increased after IVES therapy, especially in those who started therapy before 18 months of age (p = 0.019). Detrusor-sphincter dyssynergia was resolved in 55.6%. In the acontractile detrusor group, detrusor contraction ability increased in 48%, but bladder capacity did not. CONCLUSIONS: Appropriate candidates for this treatment need to be carefully selected.

Anti-visceral obesity and antioxidant effects of powdered sea buckthorn (Hippophae rhamnoides L.) leaf tea in diet-induced obese mice.

The potential health benefits of tea have long been studied. This study examined the role of powdered sea buckthorn leaf tea (SLT) in high-fat diet-induced obese mice. The mice were fed two different doses of SLT (1% and 5%, wt/wt) for six weeks. SLT suppressed body weight gain in a dose-dependent manner and significantly reduced visceral fat, plasma levels of leptin, triglyceride and total cholesterol and ALT activity compared with the high-fat-fed control mice. SLT also decreased hepatic triglyceride and cholesterol concentrations and lipid accumulation, whereas elevated fecal lipid excretion. High-fat feeding resulted in simultaneously decreasing hepatic FAS and G6PD activities and increasing PAP, ß-oxidation and CPT activities. However, SLT supplementation during high-fat feeding led to a significant decrease in PAP, ß-oxidation and CPT activities with a simultaneous increase in G6PD activity. The hepatic CYP2E1 activity and hepatic and erythrocyte lipid peroxides were significantly lowered with SLT supplements. Hepatic and erythrocyte SOD and CAT activities were also increased with SLT supplements in a dose-dependent manner, whereas GSH-Px activity was increased in erythrocytes only. These results indicate that SLT has potential anti-visceral obesity and antioxidant effects mediated by the regulation of lipid and antioxidant metabolism in high-fat diet-induced obese mice.

Comparative study of the hepatoprotective efficacy of Artemisia iwayomogi and Artemisia capillaris on ethanol-administered mice.

We compared the effects of ethylacetate extracts from Artemisia iwayomogi (AIE) and Artemisia capillaris (ACE) on ethanol-induced hepatic injury in mice. Ethanol (25% v/v, 5 g/kg body weight) was orally administered once a day for 6 wk. AIE or ACE was provided in the diet (0.05 g/100 g diet). AIE and ACE did not affect hepatic alcohol dehydrogenase activity but did significantly inhibit cytochrome P450 2E1 activity. Hepatic acetaldehyde dehydrogenase 2 activity significantly increased in the AIE group compared to the control group. AIE caused a significant decrease in plasma acetaldehyde levels and aspartate transaminase and lactate dehydrogenase activities, whereas ACE slightly decreased these values compared to the control. Hepatic catalase activity and glutathione levels were significantly increased by AIE and ACE supplements, whereas glutathione peroxidase activity was higher only in the AIE group compared to the control group. AIE and ACE supplements significantly lowered the plasma cholesterol concentration and increased the HDL-cholesterol/total cholesterol ratio compared to the control group. Compared to the control, both AIE and ACE groups showed a significant decrease in hepatic triglyceride levels and an increase in fecal triglyceride excretion simultaneous with inhibition hepatic activities of fatty acid synthase, phosphatidate phosphohyrolase, fatty acid ß-oxidation, and carnitine palmitoyltransferase. AIE significantly lowered hepatic cholesterol levels and increased fecal cholesterol levels compared to the control. These results indicate that AIE and ACE exhibit hepatoprotective and hypolipidemic properties by enhancing hepatic alcohol, antioxidant, and lipid metabolism. AIE seemed to have more potent hepatoprotective effects than ACE.

Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice.

This study investigated the efficacy of chlorogenic acid on altering body fat in high-fat diet (37% calories from fat) induced-obese mice compared to caffeic acid. Caffeic acid or chlorogenic acid was supplemented with high-fat diet at 0.02% (wt/wt) dose. Both caffeic acid and chlorogenic acid significantly lowered body weight, visceral fat mass and plasma leptin and insulin levels compared to the high-fat control group. They also lowered triglyceride (in plasma, liver and heart) and cholesterol (in plasma, adipose tissue and heart) concentrations. Triglyceride content in adipose tissue was significantly lowered, whereas the plasma adiponectin level was elevated by chlorogenic acid supplementation compared to the high-fat control group. Body weight was significantly correlated with plasma leptin (r=0.894, p<0.01) and insulin (r=0.496, p<0.01) levels, respectively. Caffeic acid and chlorogenic acid significantly inhibited fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and acyl-CoA:cholesterol acyltransferase activities, while they increased fatty acid beta-oxidation activity and peroxisome proliferator-activated receptors alpha expression in the liver compared to the high-fat group. These results suggest that caffeic acid and chlorogenic acid improve body weight, lipid metabolism and obesity-related hormones levels in high-fat fed mice. Chlorogenic acid seemed to be more potent for body weight reduction and regulation of lipid metabolism than caffeic acid.

Ursolic acid enhances the cellular immune system and pancreatic beta-cell function in streptozotocin-induced diabetic mice fed a high-fat diet.

This study investigated the effects of ursolic acid on immunoregulation and pancreatic beta-cell function in type 1 diabetes fed a high-fat diet for 4 weeks. Male mice were divided into non-diabetic, diabetic control, and diabetic-ursolic acid (0.05%, w/w) groups, which were fed a high-fat (37% calories from fat). Diabetes was induced by injection of streptozotocin (200 mg/kg B.W., i.p.). Ursolic acid significantly improved blood glucose levels, glucose intolerance, and insulin sensitivity compared to the diabetic group. The plasma insulin and C-peptide concentrations were significantly higher in the diabetic-ursolic acid group than in the diabetic group. Ursolic acid significantly elevated the insulin levels with preservation of insulin staining of beta-cells in the pancreas. In splenocytes, concanavalin (Con) A-induced T-cell proliferation was significantly higher in the diabetic-ursolic acid group compared to the diabetic group, but liposaccharide (LPS)-induced B-cell proliferation did not differ between groups. Ursolic acid enhanced IL-2 and IFN-gamma production in response to Con A stimulation, whereas it inhibited TNF-alpha production in response to LPS stimulation. In this study, neither streptozotocin nor ursolic acid had effects on lymphocyte subsets. These results indicate that ursolic acid exhibits potential anti-diabetic and immunomodulatory properties by increasing insulin levels with preservation of pancreatic beta-cells and modulating blood glucose levels, T-cell proliferation and cytokines production by lymphocytes in type 1 diabetic mice fed a high-fat diet.

Beneficial effects of curcumin on hyperlipidemia and insulin resistance in high-fat-fed hamsters.

This study investigated the effect of curcumin (0.05-g/100-g diet) supplementation on a high-fat diet (10% coconut oil, 0.2% cholesterol, wt/wt) fed to hamsters, one of the rodent species that are most closely related to humans in lipid metabolism. Curcumin significantly lowered the levels of free fatty acid, total cholesterol, triglyceride, and leptin and the homeostasis model assessment of insulin resistance index, whereas it elevated the levels of high-density lipoprotein cholesterol and apolipoprotein (apo) A-I and paraoxonase activity in plasma, compared with the control group. The levels of hepatic cholesterol and triglyceride were also lower in the curcumin group than in the control group. In the liver, fatty acid beta-oxidation activity was significantly higher in the curcumin group than in the control group, whereas fatty acid synthase, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and acyl coenzyme A:cholesterol acyltransferase activities were significantly lower. Curcumin significantly lowered the lipid peroxide levels in the erythrocyte and liver compared with the control group. These results indicate that curcumin exhibits an obvious hypolipidemic effect by increasing plasma paraoxonase activity, ratios of high-density lipoprotein cholesterol to total cholesterol and of apo A-I to apo B, and hepatic fatty acid oxidation activity with simultaneous inhibition of hepatic fatty acid and cholesterol biosynthesis in high-fat-fed hamsters.

Du-zhong (Eucommia ulmoides Oliver) leaf extract mediates hypolipidemic action in hamsters fed a high-fat diet.

This study examined the effect of a Du-zhong (Eucommia ulmoides Oliver) leaf extract (0.175 g/100 g diet) that was supplemented with a high-fat diet (10% coconut oil, 0.2% cholesterol, wt/wt) on hyperlipidemic hamsters. Hamsters fed with Du-zhong leaf extract for 10 weeks showed a smaller size of epididymal adipocytes compared to the control group. The supplementation of the Du-zhong leaf extract significantly lowered the plasma levels of triglyceride, total cholesterol, LDL-cholesterol, non HDL-cholesterol, and free fatty acid, whereas it elevated the HDL-cholesterol/total cholesterol ratio and apolipoprotein A-I levels. The hepatic cholesterol concentration was lower in the Du-zhong group than in the control group. The plasma total cholesterol concentration was positively correlated with hepatic HMG-CoA reductase activity (r = 0.547, p < 0.05) and hepatic cholesterol concentration (r = 0.769, p < 0.001). The hepatic fatty acid synthase and HMG-CoA reductase activities were significantly lowered by a Du-zhong leaf extract supplement in high fat-fed hamsters. Hepatic fatty acid synthase activity was positively correlated with plasma fatty acid concentration (r = 0.513, p < 0.05) that was lower in the Du-zhong group. These results demonstrate that the Du-zhong leaf extract exhibits antihyperlipidemic properties by suppressing hepatic fatty acid and cholesterol biosynthesis with the simultaneous reduction of plasma and hepatic lipids in high fat-fed hamsters.

Hypoglycemic and hypolipidemic action of Du-zhong (Eucommia ulmoides Oliver) leaves water extract in C57BL/KsJ-db/db mice.

The anti-diabetic efficacy of Du-zhong (Eucommia ulmoides Oliver) leaves water extract (WDZ) was investigated in type 2 diabetic animals. The WDZ was given to C57BL/KsJ-db/db mice as a dietary supplement based on 1% dried whole Du-zhong leaves (0.187 g WDZ/100 g standard diet) for 6 weeks. The WDZ supplementation significantly lowered the blood glucose level and enhanced the glucose disposal in an intraperitoneal glucose tolerance test. The plasma insulin and C-peptide levels were significantly higher in the WDZ group than in the control group, while the glucagon level was lower. The hepatic glucokinase activity was significantly higher in the WDZ group, whereas, the glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly lower. The WDZ supplementation also significantly lowered the hepatic fatty acid synthase, HMG-CoA reductase and ACAT activities compared to the control group, while it elevated the lipoprotein lipase activity in the skeletal muscle. The WDZ also altered the plasma and hepatic lipid levels by lowering the cholesterol and triglyceride concentrations, while elevating the plasma HDL-cholesterol level. Therefore, these results suggest that WDZ may partly ameliorate hyperglycemia and hyperlipidemia with type 2 diabetes through increasing glycolysis, suppressing gluconeogenesis and the biosynthesis of fatty acid and cholesterol in the liver.

Genistein and daidzein modulate hepatic glucose and lipid regulating enzyme activities in C57BL/KsJ-db/db mice.

This study examines whether anti-diabetic effects of genistein and daidzein are mediated by hepatic glucose and lipid regulating enzyme activities in type 2 diabetic animals. Male C57BL/KsJ-lepr(db)/lepr(db) (db/db) mice and age-matched non-diabetic littermates (db/+) were used in this study. The db/db mice were divided into control, genistein (0.02%, w/w) and daidzein (0.02%, w/w) groups. The blood glucose and HbA(1c) levels were significantly lower in the genistein and daidzein groups than in the control group, while glucose tolerance only was significantly improved in the genistein-supplemented group. The plasma insulin and C-peptide levels did not differ significantly between groups, yet the glucagon level was lower in the genistein and daidzein groups compared to that in the control db/db or db/+ group. The genistein and daidzein supplements increased the insulin/glucagon ratio in the type 2 diabetic animals. While the hepatic glucokinase activity was significantly lower in the db/db control group, the glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly higher in the control group compared to the db/+ group. Interestingly, these hepatic glucose metabolizing enzyme activities were reversed by the genistein and daidzein supplementation in db/db mice compared to the control group. The hepatic fatty acid synthase, beta-oxidation and carnitine palmitoyltransferase activities were all significantly lower in the genistein and daidzein groups than in the control group. The genistein and daidzein supplements also improved the plasma total cholesterol, triglyceride, HDL-cholesterol/total cholesterol, free fatty acid and hepatic triglyceride concentrations in the db/db mice. These results suggest that genistein and daidzein exert anti-diabetic effect in type 2 diabetic conditions by enhancing the glucose and lipid metabolism.

Eucommia ulmoides Oliver leaf extract increases endogenous antioxidant activity in type 2 diabetic mice.

Eucommia ulmoides Oliver (Du-zhong) leaf extract was investigated for its antioxidant effects in type 2 diabetic animals, C57BL/KsJ-db/db mice. Du-zhong extract equivalent to 1% dried whole Du-zhong leaf (0.187 g of extract/100 g of diet) was added to the experimental diets for 6 weeks. The Du-zhong extract supplement significantly lowered blood glucose concentrations and elevated plasma paraoxonase activity compared with the control group. The activities of erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were significantly higher in the Du-zhong group compared with the control group, while glutathione reductase (GR) activity was not different between groups. The activities of SOD, GSH-Px, and GR in liver and kidney were not affected by Du-zhong extract supplementation, whereas the CAT activity was significantly higher in the Du-zhong group than in the control group. Du-zhong extract supplementation resulted in lower levels of hydrogen peroxide and lipid peroxide in erythrocytes, liver, and kidney. These results suggest that the antioxidant activity of Du-zhong extract is potentially beneficial for the prevention and management of complications of type 2 diabetes.

Du-zhong (Eucommia ulmoides Oliv.) cortex water extract alters heme biosynthesis and erythrocyte antioxidant defense system in lead-administered rats.

This study examined the ameliorative effect of a Du-zhong (Eucommia ulmoides Oliv.) cortex water extract (DzCw) on heme biosynthesis and erythrocyte antioxidant enzyme activities in lead (Pb)-administered rats. Male rats were divided into three groups: normal control group, Pb control group (Pb), and DzCw-administered Pb group (Pb + DzCw). The Pb (25 mg/kg of body weight) was administered orally once a week for 4 weeks, while the DzCw was administered orally at a dosage of 0.139 g of DzCw/kg of body weight/day. DzCw administration significantly lowered plasma Pb concentration compared with the Pb group. Furthermore, the blood hematocrit and hemoglobin levels were significantly higher in the Pb + DzCw group than in the Pb group. Although the blood and hepatic delta-aminolevulinic acid dehydratase (ALAD) activities were significantly lower in the Pb group compared with the normal control group, both ALAD activities was normalized with the administration of DzCw. The erythrocyte superoxide dismutase and catalase activities were significantly higher in the Pb group than in the normal control group, whereas the glutathione peroxidase activity and glutathione level were lowered by Pb administration compared with the normal group. However, the administration of DzCw was found to enhance the antioxidant defense system and significantly lower lipid peroxidation levels in erythrocytes compared with the Pb group. These results indicate that the DzCw administration alleviated the Pb-induced oxidative stress in the erythrocytes through elevating the blood and hepatic ALAD activity and enhancing the antioxidant enzyme activities.

Hypoglycemic effect of Du-zhong (Eucommia ulmoides Oliv.) leaves in streptozotocin-induced diabetic rats.

The current study investigated whether Du-zhong (Eucommia ulmoides Oliv.) leaves could improve the hyperglycemia in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were divided into a non-diabetic group (NDM), diabetic group (DM), diabetic group supplemented with powdered Du-zhong leaves (DM-PDZ) and diabetic group supplemented with a water extract of the powdered Du-zhong leaves (DM-WDZ). Diabetes was induced by injecting STZ (70 mg/kg B.W., i.p.). The powdered Du-zhong leaves or its powdered water extract was add to a standard diet based on 1% dried Du-zhong leaves (1 g PDZ/100 g diet and 0.187 g WDZ/100 g diet, respectively) for 3 weeks. Body weight was significantly higher in both types of Du-zhong leaves supplemented groups than in the DM group. The blood glucose levels were significantly lower in the DM-PDZ and DM-WDZ groups than in the DM group (20.05+/-0.88 and 18.96+/-1.23 mmol/l versus 24.42+/-1.07 mmol/l, P<0.05), whereas the plasma insulin and C-peptide levels were significantly higher in the PDZ and WDZ supplemented groups than in the DM group (7.45+/-0.27 and 7.62+/-0.69 microl U/ml versus 3.75+/-0.27 microl U/ml for the plasma insulin, and 224.52+/-14.6 and 239.76+/-15.52 pmol/l versus 166.5+/-10.4 pmol/l for the plasma C-peptide, respectively, P<0.05). The supplementation of PDZ and WDZ also resulted in lower plasma urea nitrogen levels compared to the DM group. Du-zhong leaves supplement seemed to be helpful to preserve the normal histological appearance of pancreatic islets as well as to preserve insulin-positive beta-cells but it did not reverse the effect of STZ to a great extent. Accordingly, the reduction in plasma glucose by the powdered Du-zhong leaves and its water extract is quite small but significant, nevertheless, this was occurred with simultaneous the increase in plasma insulin and C-peptide. They improved hyperglycemia and seemingly enhance the function of pancreatic beta-cells in STZ-induced diabetic rats.