台灣栽培山藥對高血脂倉鼠之降血脂作用的機轉研究

Preventing Dyslipidemia of Dioscorea Tuber Cultivated in Taiwan Fed with High Cholesterol Fat Diet in Hamster

洪義成(I-Chen Hung)

指導教授 ： 顏銘宏

高雄醫學大學/藥學院/天然藥物研究所碩士班/碩士(2008年)

摘要

山藥在中國當作藥食同療已有千年歷史，有許多研究報告指出山藥具有抗高血脂及高血糖的作用。然而，作為保健食品，它的劑量及有效作用物的研究卻相對闕如，因此本研究利用倉鼠以高脂食物餵食檢測山藥熱水抽取物及劑量上不同的治療差異性，並與新品種山藥TA-06比較降脂功效。本實驗分成兩部分：在第ㄧ次實驗中，利用TA-05熱水抽取物管餵倉鼠高低不同濃度(TA05L，TA05H)持續四週；第二次實驗，利用已混和TA-05(HF+TA05)和TA-06(HF+TA06)山藥粉末的高脂飼料各別餵食四週。在實驗中，利用正常囓齒類飼料當作基礎飲食(BD)，而將加入Lovastatin的組別當作正向控制組(HF+LOVA)，並在實驗期間每天紀錄倉鼠體重及飲食攝取量。當28天結束後，檢測倉鼠血液、肝臟及糞便中的脂質含量，並對肝組織中SOD、GSH-Px及脂質過氧化物質作檢測。
結果：由資料顯示，TA05H、HF+TA05和HF+TA06都可以抑制肝臟重量增加(P < 0.05)，尤其在維持體重上TA05H有較高的食物效益（feed efficiency），但是HF+TA05只有些許效益。在第一實驗中血漿脂質檢測結果顯示TA05H相對HF組在Triglyceride(TG)、Total Cholesterol(TC)、LDL和Atherosclerotic index數值上有意義地降低許多(P < 0.05)，而TA05L雖有數據減少，但只在TC上呈現意義性下降(P < 0.05)；在第二實驗中，HF+TA06在TC、LDL、VLDL和動脈粥狀硬化指數上呈現優越的抑制性(P < 0.01)，但是在TG的數值雖下降但沒有統計意義。肝均質的脂質數據顯示，TA05H和HF+TA06在TC和LDL上有顯著的抑制效果(P < 0.05)。在糞便脂肪檢測上，TA05H和TA05L有促進TC排出效果(P < 0.05)，而HF+TA06在TC、LDL和VLDL有效的促進排出(P < 0.05)。在第一實驗的抗氧化數據指出，SOD呈現有劑量依存作用，但只有TA05H有統計意義(P < 0.05)；特別在第二實驗中，HF+TA05及HF+TA06的SOD在統計上皆有顯著的提高(P < 0.05)，然而在GSH-Px和MDA的實驗則都屬無意義的結果。
結論：TA-05水抽取物和TA-06粉末呈現出抗高血脂活性。TA-05水抽取物應為抑制肝臟脂肪合成而降低血脂；TA06粉末則可能：1.抗性澱粉抑制腸胃道油質吸收作用，2.抑制體脂肪形成。所有山藥的數據皆表現出可作為抑制血脂異常（過高）的食材及提供保護心血管疾病氧化狀態的高機能保健食材。

關鍵字

粥狀動脈硬化 ； 高膽固醇高油脂飲食 ； 山藥水抽取物 ； 倉鼠 ； 血漿脂質濃度

並列摘要

Dioscorea spp. (also called “Yam”) was a food and drug for many millenniums in china, recently, many reports shown its effects on anti-hyperlipidemia and -hyperglycemia. However, being nature healthy crude food and drug, its effect region and dosage was unclear. Therefore, the effects of different treatments by TA-05 extracts with various dosage for serum lipid profiles and liver antioxidant after concomitant continued high fat diet (HF) in hamsters was studied, and comparison with new Dioscorea Tuber Cultivated TA-06 by same methods to know which more better on antihyperlipidemia. This study has divided two parts. In first part, hamsters were fed with low and high concentration of TA-05 water-extracts by oral (TA05L, TA05H) for 4 weeks. The second part was mixed with high fat diet to involve TA-05 (HF+TA05) and TA-06 (HF+TA06) tuber powder for 4 weeks, individually. In this study, lovastatin was taken as the positive control (HF+LOVA) and used the normal rat chow as basal diet (BD).Weigh hamsters and food intake weight during experiment day. After 28 days, the lipids level of plasma、liver homogenates and feces in high-fat diet treated hamster were determined. Superoxide dismutase (SOD)、glutathione peroxidase (GSH-Px) and lipid peroxides of liver were also analyzed.
Results: According to the data, group TA05H, HF+TA05 and HF+TA06 inhibited fat accumulation on liver weight (P < 0.05). TA05H had higher feed efficiency that maintains body weight changeless, especially, but HF+TA05 had the ability a little. In serum lipids analysis of first part, the results indicated that TA05H group had significantly lower than those of the HF group on triglyceride (TG), total cholesterol (TC), LDL and atherosclerotic index (P < 0.05), and all the data of TA05L have decreased, but only TC was significant (P < 0.05). In the second part, the group HF+TA06 showed the superiority of inhibitor for TC、LDL、VLDL and atherosclerotic index(P < 0.01), but no significance for TG. The data of liver homogenate on TA05H and HF+TA06 had similar effect on TC and LDL and has reduced the liver-cell fat accumulation. The fecal lipids represent had observable elevated on TG、TC and VLDL (P < 0.05), but only the TC had statistically significant. SOD activity has observed dose-dependant at first part study; but only TA05H had significant (P < 0.05). SOD values from HF+TA05 and HF+TA06 on second part study have noticeable elevation, specially, and observed the same effects by statistically significant (P < 0.01). And the data of GSH-Px and MDA concentration showed no significance.
Conclusion: water extracts of TA-05 and raw powder of TA-05 and TA-06 exhibited hypolipidemic activity. TA-05 water-extracts should be inhibiting liver fat formation to reduced lipid concentration. And TA-06 raw powder may be suppressed oil absorption by resistant starch and inhibited body fat formation. All the data of yam suggested to be used in the development of functional food for the modification of lipid profile and oxidative status in prevention of cardiovascular diseases.

並列關鍵字

Atherolsclerosis ； High cholesterol fat diet ； YAM Water extracts ； YAM ； Hamsters ； Plasma lipid concentration

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