The effects of coenzyme Q₁₀ supplement on blood lipid indices and hepatic antioxidant defense system in SD rats fed a high cholesterol diet / 한국실험동물학회지

A total of 24 SD rats were allotted to four treatment groups such as the control (CON), 1% of cholesterol diet (CHO), 0.5% of coenzyme Q₁₀ (COQ) and 1% of cholesterol plus 0.5% of coenzyme Q₁₀ (CHCQ) groups to determine the effects of coenzyme Q₁₀ (CoQ₁₀) on the antioxidant defense system in rats. The body weight, weight gain, liver weight and abdominal fat pads were unaffected by 0.5% of CoQ₁₀ supplement in the rats. The level of triglyceride and HDL-cholesterol levels in the blood was significantly increased (p< 0.05) by the 1% of cholesterol supplement (CHO), whereas 0.5% of CoQ₁₀ supplement (COQ) did not alter these blood lipid indices. In the mRNA expression, there was a significant effect (P < 0.05) of the CoQ₁₀ supplement on the mRNA expression of superoxide dismutase (SOD), although the mRNA expression of glutathione peroxidase (GPX) and glutathione S-transferase (GST) was unaffected by cholesterol or the CoQ₁₀ supplement. Similar to mRNA expression of SOD, its activity was also significantly increased (P < 0.05) by CoQ₁₀, but not by the cholesterol supplement effect. The activities hepatic GPX and GST were unaffected by CoQ₁₀ and cholesterol supplements in rats. Lipid peroxidation in the CHO group resulted in a significant (p< 0.05) increase compared with that in the other groups, indicating that the CoQ₁₀ supplement to 1% of cholesterol-fed rats alleviated the production of lipid peroxidation in the liver. In conclusion, 0.5% of the CoQ₁₀ supplement resulted in positive effects on the hepatic antioxidant defense system without affecting blood lipid indices in 1% of cholesterol fed rats.

Effects of dietary lipid-coated zinc on the antioxidant defense system in the small intestine and liver of piglets / 한국실험동물학회지

The purpose of the study was to investigate the effects of lipid-coated ZnO (LCZ) and the level of LCZ compared with ordinary zinc oxide (ZnO) on antioxidant defense system in the intestine and liver of piglets. A total of forty piglets (n=8) were fed a diet supplemented with 100 ppm Zn with ZnO (ZnO-1), 2,500 ppm Zn with ZnO (ZnO-2), 100 ppm Zn as LCZ (LCZ-1), 200 ppm Zn as LCZ (LCZ-2), or 400 ppm Zn as LCZ (LCZ-3) for 14-d, respectively. The LCZ-3 group resulted in higher (P < 0.05) mRNA expressions and activities of CuZn-superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and glutathione S-transferase (GST) in jejunal mucosa compared with the ZnO-1 and LCZ-1 groups, while no difference was observed in the mRNA level of antioxidant genes between the ZnO-1 and ZnO-2 groups. Within the LCZ groups, the LCZ level linearly and quadratically (P < 0.01) increased antioxidant enzymes in the jejunum. The maximum response of jejunal antioxidant enzymes to Zn supplementation was achieved by 400 ppm of LCZ. Hepatic mRNA expression of antioxidant enzymes was unaffected by Zn source and level, while hepatic SOD and GST activities were greater (P < 0.05) in the LCZ-3 group than in the ZnO-1 group. No difference was observed in lipid peroxidation of the jejunum and liver and the total antioxidant power of plasma among groups. In conclusion, a supplementation with 400 ppm of LCZ resulted in a maximum increase in antioxidant enzymes, indicating that LCZ may affect antioxidant defense system more profoundly than ZnO.

Effects of coenzyme Q₁₀ on the antioxidant system in SD rats exposed to lipopolysaccharide-induced toxicity / 한국실험동물학회지

The study was performed to see the effects of coenzyme Q₁₀ (CoQ₁₀) on blood biochemical components and hepatic antioxidant system in rats exposed to lipopolysaccharide (LPS)-induced toxicity. A total of 24 rats were allocated to four groups: control (CON), 100 mg/kg BW of LPS (LPS), 100 mg of CoQ₁₀/kg BW with LPS (LCQI) and 300 mg of CoQ₁₀/kg BW with LPS (LCQII). The LPS and LCQI groups showed a significant (P<0.05) increase in the relative spleen weight compared with the CON group without affecting body and liver weights. The blood alanine aminotransferase (ALT) level in the LPS group was significantly (P<0.05) greater than that in the CON group, while supplementation with 100 or 300 mg CoQ₁₀ to rats injected with LPS normalized the ALT level in the CON group. In antioxidant systems, the LPS group showed a significantly (P<0.05) higher mRNA and activity of superoxide dismutase (SOD) than the CON group. The supplementation with CoQ₁₀ to the LPS-treated group normalized the level of SOD, which was comparable to the level of the CON group. Both the mRNA expression and activity of glutathione peroxidase in the LCQI and LCQII groups were higher (P<0.05) than that of the LPS group. However, administration of LPS or CoQ₁₀ unaffected the level of catalase and total antioxidant power. The level of lipid peroxidation in the LCQII group was lower (P<0.05) than that in the LPS group. In conclusion, CoQ₁₀ exerted its favorable effect against liver damage by modulation of antioxidant enzymes in LPS treated rats.

Effects of lutein or lutein in combination with vitamin C on mRNA expression and activity of antioxidant enzymes and status of the antioxidant system in SD rats / 한국실험동물학회지

This study was conducted to investigate the effects of lutein alone or in combination with vitamin C on the antioxidant defense system in rats. A total of 18 eight-week-old male Sprague Dawley (SD) rats were randomly assigned to three groups for 4 weeks: control (CON), lutein (LUT, 50 mg lutein/kg BW) and lutein plus vitamin C (LVC, 50 mg lutein/kg BW+1,000 mg vitamin C/kg BW). No differences in body weight, relative live weight or plasma biochemical profiles were observed among treatment groups. In the hepatic antioxidant defense systems, the mRNA expression of superoxide dismutase (SOD) in the LUT and LVC groups was significantly (P<0.05) higher than that in the CON group, whereas the mRNA level of glutathione peroxidase (GPX), catalase (CAT) and glutathione S-transferase (GST) was not affected by the administration of antioxidants. SOD and GST activities in the LUT and LVC groups were significantly higher (P<0.05) than those in the CON group, whereas GPX, CAT and lipid peroxidation did not differ among groups. In addition, the LVC group showed a significant (P<0.05) increase in plasma and hepatic total antioxidant power (TAP) relative to the CON group. Overall, administration of lutein in combination with vitamin C improved the status of the total antioxidant defense system in SD rats.

Effects of Steaming Time and Frequency for Manufactured Red Liriope platyphylla on the Insulin Secretion Ability and Insulin Receptor Signaling Pathway / 한국실험동물학회지

In oriental medicine, Liriope platyphylla (LP) has long been regarded as a curative herb useful for the treatment of diabetes, asthma, and neurodegenerative disorders. The principal objective of this study was to assess the effects of steaming time and frequency for manufactured Red LP (RLP) on insulin secretion ability and insulin receptor signaling pathway. To achieve our goal, several types of LPs manufactured under different conditions were applied to INS cells and streptozotocin (STZ)-induced diabetic ICR mice, after which alterations in insulin concentrations were detected in the culture supernatants and sera. The optimal concentration for the investigation of insulin secretion ability was found to be 50 ug/mL of LP. At this concentration, maximum insulin secretion was observed in the INS cells treated with LP extract steamed for 3 h (3-SLP) with two repeated steps (3 h steaming and 24 h air-dried) carried out 9 times (9-SALP); no significant changes in viability were detected in any of the treated cells. Additionally, the expression and phosphorylation levels of most components in the insulin receptor signaling pathway were increased significantly in the majority of cells treated with steaming-processed LP as compared to the cells treated with LP prepared without steaming. With regard to glucose transporter (GLUT) expression, alterations of steaming time induced similar responses on the expression levels of GLUT-2 and GLUT-3. However, differences in steaming frequency were also shown to induce dose-dependent responses in the expression level of GLUT-2 only; no significant differences in GLUT-3 expression were detected under these conditions. Furthermore, these responses observed in vitro were similarly detected in STZ-induced diabetic mice. 24-SLP and 9-SALP treatment applied for 14 days induced the down-regulation of glucose concentration and upregulation of insulin concentration. Therefore, these results indicated that the steaming processed LP may contribute to the relief of diabetes symptoms and should be regarded as an excellent candidate for a diabetes treatment.

Effect of Long-Term Food Restriction on Nitric Oxide Synthase-Positive Neurons in Rat Cerebral Cortex / 대한해부학회지

Nitric oxide is synthesized by cells containing the nitric oxide synthase (NOS), and NADPH-diaphorase (NADPH-d) is a selective histochemical marker for the NOS in the brain. The influence of feeding rats only half the amount of their normal daily intake of a purified diet on NOS was measured in the cerebral cortex by immunohistochemistry and NADPH-d histochemistry. iNOS was not detected in the cerebral cortex of control group. iNOS-positive neurons were induced in the cerebral cortex at 1 week after food restriction and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, parietal association cortex, auditory cortex, visual cortex, temporal association cortex and retrosplenial cortex. At 2 weeks after food restriction, iNOS-positive neurons were not found in all cortical areas. At 4 weeks after food restriction, iNOS-positive neurons were found in ectorhinal cortex and perirhinal cortex. In samples obtained 3 days after food restriction, the staining intensity of NADPH-d-positive neurons was decreased in most cortrical regions compared to the control group. At 1 week after food restriction, the staining intensity of NADPH-d was significantly increased in isocortical regions compared to the control group. At 9 weeks after food restriction, the staining intensity of NADPH-d was significantly decreased in all cortical regions. NO, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced iNOS-positivity and upregulated NADPH-d-positive neurons may affect the neuronal activity in the cerebral cortex after food restriction.