本研究之主要目的為探討蒸熟之台農二號山藥 (Dioscorea alata L. cv. Tainung No. 2) 對去卵巢雌鼠之腰椎骨、股骨骨質密度和腸道生理的影響。Balb/c雌鼠8週齡大時，進行偽手術 (Sham) 或去卵巢手術 (OVX)。手術後第3天起開始餵飼實驗飼料，OVX鼠隨機分置於OVX、E2 (2 microgram 17 beta-Estradiol /g diet)、山藥 (Yam；63%) 及金雀異黃酮 (Genistein；200 microgram/g diet) 組。Sham及OVX組餵飼控制飼料，其組成主要參考AIN-93G配方，但是油改採玉米油，山藥組則是利用山藥粉取代所有玉米澱粉。實驗為期十二週皆採自由飲水及攝食，其後斷頭犧牲老鼠，採集血液、股骨及腰椎骨以進行後續分析。結果顯示各組生長效率相似，E2組之腰椎骨及股骨骨質密度皆與Sham組相似。Yam組之腰椎骨骨質密度、鈣質/灰份比例和鈣質重及血鈣濃度皆與Sham組及Genistein組相似，且顯著高於OVX組；而腰椎骨乾重及灰份重則介於Sham及OVX組之間。Yam組股骨骨質密度亦與Sham組及Genistein組相似，且顯著高於OVX組，然而，山藥具有部分延緩腰椎骨和股骨重量的流失作用。
在腸道生理方面，Yam組每日糞便重量、糞便含水率和盲腸短鏈脂肪酸濃度皆顯著高於其他各組。同時，山藥也顯著提高每日總短鏈脂肪酸、乙酸、丙酸和正丁酸的排出量。
因此本研究建議蒸熟之台農二號山藥能有效延緩停經後骨質密度的流失並是腸道發酵的良好基質。
The main purpose of this study was to investigate the effects of Dioscorea alata L. cv. Tainung No. 2 on lumbar and femur bone density, and on gut function in ovariectomized female Balb/c mice.
Mice were sham-operated or ovariectomized (OVX) at age of 8 weeks and were fed experimental diets after 3 days. Sham-operated mice (sham) were fed control diet (AIN-93G with corn oil) while OVX mice were randomly allocated into OVX (control diet), E2 (2 mg 17 beta-Estradiol /100 g diet), yam (63 g yam powder/100 g diet) or genistein (200 mg/100 g diet) group. After 12 wk of experiment, mice were decapitalized. Blood, femur, lumbar bones and cecal contents were collected for further analyses.
There was no significant difference in food efficiency between groups. Supplementation of E2 completely restored the mineral density (g/cm2) of lumbar and femur bones, respectively, to the level of sham group. Mineral density of lumbar bone and femur, calcium to ash ratio, and calcium content of femur and concentration of serum calcium were restored by both yam and genistein to the levels of sham group. Dry weight and ash content of lumbar bones of yam group tended to increase as compared to the OVX group. The fecal weight and moisture, short chain fatty acid concentrations of cecal content and its daily fecal output were the greatest in mice fed the yam diet.
In summary, Tainung No. 2 yam that is well-fermented in the large bowel could effectively delay the postmenopausal bone loss.
