Recent studies indicated that Atherosclerosis was thought to the resulted from high blood lipid and oxidative stress. Dioscorea has been recognized as an edible medicinal herb as well as healthy plant. Related studies showed that Taiwannative yam (Dioscorea) exhibited hypoglycemic, antioxidative and hypolipidemic functions. However, researches regarding the best species of native Dioscorea revealing the efficacy with both antioxidative and hypolipidemic functions are limited. Previously our laboratory, found that three in five native species of Dioscorea provided by the Agricultural Research Institute had antioxidative effects. The goal of this study was to investigate the effects of this three Dioscorea species (TA01¡BTA03¡BTA05) on lipid metabolism and antioxidative ability of hamsters.
Hyperlipidemia hamsters induced by feeding high fat and high cholesterol diet for 3 weeks, were randomly divided into five groups. Group 1 was the control group fed with a high fat and high cholesterol diet (HF, 0.2% cholesterol and 12% fat) ; group 2 was the positive control group fed with a HF diet supplemented with 0.08% atorvastatin (HF+ATS) ; group 3 was TA01 group fed with a HF diet supplemented with 10% TA01 yam powder (HF+TA01) ; group 4 was TA03 group fed with a HF diet supplemented with 10% TA03 yam powder (HF+TA03) ; group 5 was TA05 group fed with a HF diet supplemented with 10% TA05 yam powder (HF+TA05). The experiment was conducted for 12 weeks. Blood was collcted to determine serum total cholesterol (TC) and triglycerol (TG) at week 4 and 8. The hamsters were scarified and the blood, liver and epididymal fat pads were collected at week 12. The weight of body, liver, epididymal fat pads ; Serum TC, TG, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and oxidation of LDL (thiobarbituric acid reactive substances, TBARS) were determined ; TC, TG, TBARS, superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione reductase (GR) of liver were also analyzed.
Results indicated that TA01 group had significantly decreased serum TG (P < 0.05) at 4 and 8 weeks. Serum TC and TG of TA03 group were significantly lower than those of the control group at 8 weeks. No significant difference for TC and TG was found between TA05 and the control groups. After 12 weeks of Dioscorea feeding, liver weight and liver to body weight ratio of TA01 and TA03 groups compared to that of control group were significantly reduced. Epididymal fat pads weight and that the body weight ratio tended to be less compared to that of the control group. Serum TG concentration of TA01 was significantly decreased to 89% of the control group. Serum TC, TG and LDL-C concentrations of TA03 group were significantly decreased to 82, 89 and 83% of the control group, respectively. Serum HDL-C of TA03 group was unaffected and LDL TBARS tended to be decreased (1.67 ¡Ó 0.79 vs. 1.06 ¡Ó 0.57) compared to that of the control group. Liver TC concentrations of TA01 and TA03 groups both were significantly decreased to 88% of the control group. Liver TG and TBARS of TA01 and TA03 groups were unchanged. Catalase activities of TA01 and TA03 groups and GR activity of TA01 group were significantly higher than those of the control group. No significant differences were found in GPx and SOD activities among all groups.
In conclusion, TA01 and TA03 species of Taiwannative yam (Dioscorea) tubers exhibit beneficial effects on lipid profile and antioxidative status for hyperlipidemia induced by a high fat and high cholesterol diet. Among there species, TA03 reveals the best potential with both hypolipidemic and antioxidant effects, and was suggested to be used in the development of functional food for the modification of lipid profile and oxidative status in cardiovascular disease prevention .
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0803105-221102 |
| Date | 03 August 2005 |
| Creators | Wang, Chiung-yean |
| Contributors | Chung-Lung Cho, Ching-Mei Hus, Sue-Joan Chang, Meng-Tsan Chiang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0803105-221102 |
| Rights | not_available, Copyright information available at source archive |
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