苦荞黄酮降低血糖和血脂的作用途径

Effective way of tartary buckwheat flavone reducing the level of blood glucose and blood lipid

目的：探讨苦荞黄酮类化合物降低血糖和血脂的作用途径。 方法：实验于2004-04／05在解放军总医院营养科实验室进行。选择昆明雄性小鼠64只。①体外实验：以阿卡波糖为阳性对照，检测苦荞黄酮对糖苷酶活性的影响。②糖耐量实验：分别在不同时间进行淀粉、蔗糖、葡萄糖耐量实验。取20只小鼠，实验前禁食12h后测空膜血糖，将小鼠随机分为2组，每组10只，苦荞黄酮组和对照组小鼠分别灌胃苦荞黄酮(1g／kg)+淀粉(2g／kg)混合物和淀粉(2g／kg)，于灌胃后1h测定两组小鼠血糖。蔗糖、葡萄糖实验均应用以上两组小鼠，实验前均禁食12h测空腹血糖，苦荞黄酮组和对照组小鼠分别灌胃给予苦荞黄酮(1g／kg)+蔗糖、葡萄糖(2g／kg)混合物和蔗糖、葡萄糖(2g／kg)，分别于灌胃后0．5h测定两组小鼠血糖。③三酰甘油实验：取20只小鼠，动物禁食12h后测空腹三酰甘油，将小鼠随机分为2组，苦荞黄酮组和对照组各10只，分别灌胃给予苦荞黄酮(1g／kg)+橄榄油乳液(20mL／kg)混合物和橄榄油乳液(20mL／kg)，于灌胃后1．5和3h测定三酰甘油。另取24只小鼠，随机分为2组，苦荞黄酮组和对照组各12只。两组均给予高脂肪高胆固醇饲料喂养，苦荞黄酮组添加苦荞黄酮(0．5g／kg)。饲养4周后，禁食12h，取血测定两组小鼠血三酰甘油水平。④通过体外CV-1细胞培养检测苦荞黄酮对过氧化物体增殖剂激活型受体α和γ的活性变化。 结果：纳入64只小鼠，全部进入结果分析，无脱失。①苦荞黄酮对糖苷酶活性的影响：苦荞黄酮具有明显抑制糖苷酶活性的作用，在高浓度(250mg／L)时，苦荞黄酮和阿卡波糖对糖苷酶活性的抑制率分别达85．0％和62．6％。②苦荞黄酮对小鼠血糖水平的影响：苦荞黄酮组小鼠口服淀粉1h后和口服蔗糖0．5h后的血糖水平显著低于对照组[(8．23±1．86，9．73±1．05)mmol／L；(8．91±1．65，11．06±2．31)mmol／L(t=2．221，2．395，P<0．05)]。③苦荞黄酮对小鼠三酰甘油水平的影响：苦荞黄酮组小鼠口服橄榄油3h后血三酰甘油水平显著低于对照组[(5．23±2．33，9．00±2．91)mmol／L(t=3．198，P<0．01)]。给予高脂肪和高胆固醇饲料4周后，苦荞黄酮组小鼠的血三酰甘油水平明显低于对照组[(1．17±0．27，1．30±0．18)mmol／L(t=2．144，P<0．05)]。④苦荞黄酮能够明显激活过氧化物体增殖剂激活型受体α和γ的活性，且随着苦荞黄酮浓度的增加而增高，呈现明显的剂量-效应关系。 结论：苦荞黄酮具有降低血糖及血脂的作用，其作用途径可能是通过抑制糖苷酶、三酰甘油，激活过氧化物体增殖剂激活型受体γ和α而实现的，与以往的结论一致。

AIM：To explore the effective way of tartary buckwheat, flavonoid, lightening blood glucose and blood lipid. METHODS： The experiment was conducted at the laboratory of Department of Nutrition, General Hospital of Chinese PLA from April to May 2004. Sixty-four Kunming male mice were selected. ① Experiment in vitro： Taking acarbose as positive control, the effects of tartary buckwheat flavone on activity of glycosidase. ② Experiment of glucose tolerance： The experiments on starch, saccharu and glucose tolerance were conducted at different time, respectively. Twenty mice were gained, and fasting for 12 hours before experiment the fasting glucose was detected. The mice were divided randomly into 2 groups with 10 mice in each group. The mice in the tartary buckwheat flavone group and control group were treated with gastric perfusion with the mixture of tartary buckwheat flavone （1 g/kg）＋ starch （2 g/kg） and starch （2 g/kg）, respectively, and the glucose of rats in the two groups was detected after gastric perfusion for 1 hours. The saccharu and glucose experiment were performed using the above- mentioned mice in the two groups. The mice were fasting for 12 hours before experiment, and the fasting glucose was detected. Those in the tartary buckwheat fiavone group and control group were treated with gastric perfusion with mixture of tartary buckwheat fiavone （1 g/kg）＋saccharu and glucose （2 g/kg） with saccharu and glucose （2 g/kg）, respectively. The blood glucose in mice of the two groups was detected after gastric perfusion for 0.5 hour. ③ Triacylglycerd experiment： Twenty mice were gained, after fasting for 12 hours the fasting triacylglycerol was detected, and the mice were assigned into 2 groups randomly with 10 mice in the tartary buckwheat fiavone group and control group, respectively. They were treated with gastric perfusion with mixture of tartary buckwheat fiavone （ 1 g/kg）＋ dive oil cream （20 mL/kg） and olive oil cream （20 mL/kg）, and the triacylglycerol was detected after 1.5 and 3 hours of gastric perfusion. Other 24 mice were collected, and divided randomly into 2 groups, with 12 mice in tartary buckwheat fiavone group and control group. The mice in the two groups were all fed with high lipid and high cholesterol feed, and those in the tartary buckwheat flavone group were added with （0.5 g/kg） tartary buckwheat fiavone. After feeding for 4 weeks, fasting for 12 hours, the blood was gained to detect the level of triacylglycerel in the mice of the two groups. ④ Effects of the tartary buckwheat fiavone on activities of peroxisome proliferator-activated receptor α and γ were tested through CV- 1 cell culture in vitro. RESULTS： The 64 included mice were all involved in the result analysis, without drop. ① Effects of tartary buckwheat fiavone on activity of glycosidase： The tartary buckwheat fiavone had significantly inhibitive effects on activity of glycosidase. With the high concentration of （250 rag/ L）, the inhibitive rates of tartary buckwheat flavone and acarbose on activity of glycosidase reached 85.0% and 62.6%, respectively. ② Effects of tartary buckwheat fiavone on blood glucose level in mice： After the mice in the tartary buckwheat fiavone group taking starch orally for 1 hour and saccharu orally for 0.5 hour, the level of blood glucose was significantly lower than that in the control group [（8.23±1.86,9.73±1.05）mmol/L; （ 8.91 ± 1.65,11.06±2.31 ）mmol/L （t =2.221,2.395,P 〈 0.05 ）]. ③ Effects of tartary buckwheat fiavone on level of triacylglyceroh After the mice in the tartary buckwheat fiavone group taking olive oil for 3 hours, the level of triacylglycerol was lower obviously than that in the control group [（5.23± 2.33,9.00±2.91 ）mmol/L（t=3.198,P 〈 0.01 ）]. Four weeks after giving high lipid and high cholesterol feed, the level of triacylglycerol in the tartary buckwheat flavone group was lower significantly than that in the control group [ （ 1.17±0.27,1.30±0.18 ）mmol/L （t=2.144,P 〈 0.05 ）]. ④ The tartary buckwheat flavone could significantly activate the activities of peroxisome proliferator-activated receptor α and γ, and increased with the rose of tartary buckwheat flavone concentration, showing obviously dosage-effect relation. CONCLUSION： The tartary buckwheat flavone has the effects of lightening blood glucose and blood lipid, which can carry out by inhibiting the glycosidase, triacylglycerol and activating the peroxisome proliferatoractivated receptor α and γ and coincide with the prevenient conclusion.