A Study on the Extract of Tartary Buckwheat II. Adjustment of Blood Sugar and Blood Fat in Rats and Mice by Using the Extract of Tartary Buckwheat

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1 The proceeding of the th ISB :623-62(200 1) A Study on the Extract of Tartary Buckwheat II. Adjustment of Blood Sugar and Blood Fat in Rats and Mice by Using the Extract of Tartary Buckwheat Lin Rufa, Zhou Yunning, Wang Rui and Li Jianying Shanxi Academy of Agricultural Sciences, Taiyuan, , China ABSTRACT This paper presents partial result of the study on the extract of tartary buckwheat. The experiment observed the effect of the extract on the rats with hyperglycemai caused by alloxan as well as the effect on the rats with hyperlipemia. The results showed that the extract had no influence on the blood sugar of normal rats, but had obvious effect on rats with hyperglycemia when it was taken at large or medium dosage. The extract could also improve sugar tolerance in the rats. Large dosage of the extract could significantly be lower the TC level in the serum of the rats and medium dosage could significantly be lower the TG level. Key words: extract of tartary buckwheat blood sugar blood fat adjustment INTRODUCTION Fagopyrum tataricum is also called tartary buckwheat. It is a kind of resource crop with high nutrition and medicinal value. Apart from high level of protein and fat, it contains not only mineral elements and active microelements, but also biologically active substances like rutin, quertin and flavonoids. Flavonoids in tartary buckwheat have functions like preventing cardiovascular or cerebrovascular sclerosis, promoting digestion and raising immunity. Products of tartary buckwheat in daily life are helpful in lowering blood sugar, blood fat and glucose in urine and they can also give good treatment effect on diabetes. In the experiment, the extract was perfused into the stomach of the tested rats and mice to observe its effect on blood sugar and fat in the mice with hyperlipemia caused by alloxan. MATERIALS AND METHODS 1. Blood sugar 1) Sample: extract of tartary buckwheat, powder 2) Tested animals. Wistar male rats, body weight g, provided by Reproduction Farm, Experimental Animal Institute of Chinese Medicinal Academy. They were given the feed prepared by the farm for one week and then stopped feeding for hours to measure blood sugar of normal rats under empty stomach condition. The tested animals were divided into control and three treated groups with dosage five, ten or twenty times more than the recommended for humans. Measure blood sugar after perfusing with the extract for 20 days. The control group was perfused with distilled water. 3) Blood sugar test with hyperglycemia animal model. Separate Wistar male rats were given

2 the prepared feed for 5 days. Eight hours after stopping feeding but not water, inject alloxan (produced by Sigma cooperation, batch No ) into the vein of tail at the dosage of 65 mg/kg/bw. Seven days later get blood from eye socket to measure blood sugar. Those with blood sugar above 16 mmol/l were divided randomly into four groups of ten rats each. 27 days after perfusion and eight hours after stopping feeding, take blood sample from eye socket to measure blood sugar under the condition of empty stomach. 4) Sugar tolerance test with hyperglycemia animal model. Make sugar tolerance test ten days after perfusion. After measuring the blood sugar under the condition of empty stomach, perfuse the stomach with 25% glucose at the dosage of 1 ml/loo g.bw. One or two hours later, take blood sample to measure blood sugar again. 5) Blood sugar test. Using oxidase method, the test was made using Beckman Sampler 700s auto-analyzer. Glucose agent was produced by Beijing Bio-engineering Corporation. 6) Data processing. Variance analysis and t test for all the data were processed by the software spss/pc. 2. Blood fat 1) Sample. Extract, powder, recommended dosage 1.5 gl day. 2) Tested animals. Wistar male rats, second grade, provided by Reproduction Farm, Experimental Animal Institute of Chinese Medicinal Academy, body weight] g. 3) Dosage. High fat feed was provided by Reproduction Farm, Experimental Animal Institute of Chinese Medicinal Academy, which contained 93% basic feed, ].5% cholesterol, 5% lard and 0.2% bile salt. The feed was perfused into the stomach of the tested animals at the rate of 1 mil rat?day. There were four groups, control one, small dosage one, medium dosage one and large dosage one, which were given the dosage ten, twenty or thirty times more than the recommended. Observation period was 2 days. Stop feeding for 12 hours before take blood sample. 4) Apparatus and reagents Body weight scale, quality certificate Beckman sampler 700s auto-analyzer Reagents for testing TC, TC and HDL-C were purchased from Beijing Bio-engineering corporation, China 5) Experimental method. After giving the rats basic feed for 5 days, stop feeding, measure body weight, take blood sample from tail, and measure TC, TG and HDL-C using enzyme method. According to body weight and TC level, divide the rats into small, medium and large dosage groups as well as control group. When the experiment began, change for high fat feed, which was prepared to required concentration with distilled water and perfused into the stomach. On the 14th and 25th day, weigh the tested animals and take blood sample from the tail to measure various indexes of blood fat. 6) Statistical data. Using t test to check the significant difference for various indexes between the control and other treated groups. RESULTS AND DISCUSSION 1. Blood sugar ] ) Influence of the extract on body weight. During the experimental period, the growth and

3 development of the tested rats were normal. Variance analysis indicated that there was no difference for body weight between the control and the treated. 2) Influence of the extract on the blood sugar of normal rats is shown in Table 1. Table I shows that after given the tested substance, there was no significant difference for blood sugar between the treated and the control. This proves that the extract has no influence on blood sugar of normal rats. Table 1. Influence of the extract on the blood sugar of normal rats Group No. of animals Blood sugar Before test Control 5.72±OA9 small dosage group 5.7±0.36 medium dosage group 5.1 ±0.3 large dosage group 5.5±OA5 After test 5.5 ±OAO 5.61 ± ±O ±OA4 3) Influence of the extract on rats with hyperglycemia caused by alloxan Table 2 shows that 27 days after giving the tested substance, blood sugar of the treated groups under empty stomach condition was decreased greatly compared with the control. The difference before and after the test for the treated groups was significant, indicating that the extract could be lower the blood sugar level of the rats with hyperglycemia caused by alloxan. Table 2. Influence of the extract on the blood sugar of the rats with hyperglycemia caused by alloxan. Group No. of Blood sugar animals before test after test Difference p Control ± ±OA7 small dosage group ± ± ±6.56 medium dosage group ± ± 1.7* 7A6 ± 4.11 * <0.05 large dosage group ± ±4.69* 4.55±5.93* < ± ±3.50* 3.16±5.7* <0.05 *Compared with the control group, P< Before test F = OA67 for each group and after test F= 6.539, P<O.Ol 4) Influence of the extract on the sugar tolerance of the rats with hyperglycemia caused by alloxan. Influence of the extract on the sugar tolerance of the rats is shown in Table 3 and Table 4. Table 3. Influence of the extract on the sugar tolerance of the rats with hyperglycemia caused by alloxan Group No. of Blood sugar animals At empty stomach 1 hour after perfusion Two hours after perfusion normal ±0.53 Control ± ± ±3.69 small dosage group ± ± ±4.50 medium dosage group ± A4±4A6* 30.3±3.14 large dosage group ± A6± ±1.1* *Compared with the control group, p>0.05. According to variance analysis, under empty stomach condition, F = 0.949, P> One hour after perfusion, Fl = 1All, P<O.OOO. Two hours after perfusion, F2 = 6.674, P< One hour after perfusion with glucose, blood sugar of medium and large dosage groups is significantly lower than that of the control. Two hours after perfusion, blood sugar of large dosage group is significantly lower than that of the control

4 Table 4. Influence of the extract on the sugar tolerance of the rats with hyperglycemia caused by alloxan Group No. of animals Increase or decrease of blood sugar (mmolll) 1h - Oh P 2h - 1h P Control ± ±4.12 Small dosage group ± 6.0* < ±6.94* medium dosage group ±5.36 < ±4.51 * <0.05 large dosage group ±3.01 < ±2.02 <0.05 *Compared with the control, P<0.05. F= for 1 h - Oh by variance analysis, P<O.OOO, F=5.446 for 2h-l h, P<0.003 Table 3 and Table 4 indicate that one or two hours after perfusion with glucose, the blood sugar of medium and large dosage groups was obviously lower than that of the control when feeding the tested substance. The difference of blood sugar increase for medium and large dosage groups was also lower than that of the control. 2. Blood fat I) Influence of the extract on body weight. During the whole experimental period, the tested rats grew and developed normally. There was no difference for body weight between treated groups and the control. 2) TC concentration in serum. On the 2'h day, TC concentration in serum for large dosage group lowered significantly compared with the control. There was statistical difference (t = >t 2U«W5)=2.06, P< 0.05) (table 5) Table 5. TC level in serum on the 0, 14'h, 2'h day (mmolll,msd) Group No. of animals 0 day Control ±O.20 Small dosage group ±0.17 Medium dosage group ±0.20 Large dosage group ±0.22 * Compared with the control, P< days 2.5 ± ± ± ± days 3.2± ± ± ±0.50 3) TG level in serum. Compared with the control, TG of medium dosage group decreased significantly on the 2'h day, and there was statistical difference, t = > t 2U(IUl5)= 2.06, p<0.05. (table 6) 4) HDL-C level in serum. HDL-C level in serum is shown in Table 7. There was no statistical difference between the three treated groups and the control (p>0.05). 5) Ratio of HDL-C to TC. The ratio reflects the percentage of HDL-C, protective factor for cardiovascule, in TC. It can be seen from Table that the large dosage group had higher ratio of HDL-C to TC than the control, but there was no statistically significant difference

5 Table 6. TG level in serum on the 0,14'\ 2'h day (mmol/l,msd) Group No. of animals 0 day Control II 0.74 ±0.24 Small dosage group ±0.11 Medium dosage group ±0.12 Large dosage group II 0.67 ±0.14 * Compared with the control, P<0.05 Table 7. HDL-C level in serum on the 0, 14 th, 2 th day (mmol/l,msd) Group No. of animals 0 day Control II 1.09 ±0.12 Small dosage group ±0.16 Medium dosage group ±0.14 Large dosage group ± days 1.73 ± ± ± ± days 0.5 ± ± ± ± days 2.19± ± ± ± days 0.2 ± ± ±0.1O 0.1 ±0.06 Table. HDL-C/ TC level in serum on the 0, 14 t \ 2 th day (mmol/l,msd) Group No. ofanimals 0 day 14 days Control ± ±0.0 Small dosage group II 0.51 ± ±0.07 Medium dosage group ± ±0.04 Large dosage group ± ± days 0.26± ± ± ±0.07 6) Influence of the extract on the blood fat of rats. Influence of the extract on the blood fat of rats can be seen in Table 9. When giving the extract for 2 days at small, medium or large dosage, TC of the large dosage group decreased by.%, 11.0% and 14.6% respectively and TG by 13.7%,22.% and 19.2% respectively, HDL-C decreased by 6.1%,1.2% and 1.2 % respectively. It can be seen that the extract has adjusting function on TC and TG. Table 9. Influence of the extract on the blood fat of rats Dosage TC(%) small dosage group -. medium dosage group large dosage group TG(%) HDL-C(%) CONCLUSION 1. The extract of tartary buckwheat has no influence on blood sugar of normal rats. The extract given at medium or large dosage has obvious effect of alleviating hyperglycemia caused by alloxan in rats under empty stomach condition and improves sugar tolerance of rats. The extract has supplementary action of adjusting blood sugar. 2. Compared with the control which was given high fat feed, the extract at large dosage can decrease significantly the TC level of rats and the extract at medium dosage can decrease significantly TG level, P < The extract of tartary buckwheat has supplementary action of adjusting blood fat

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