Abstract: In order to explore whether the intake of alfalfa saponins can cause intravascular hemolysis. A total of 180 mice were selected and divided into 6 treatment groups according to their body weight and sex, with 3 replicates in each treatment, and with 10 mice in each replicate. A 1 mL gavage containing 0.0125, 0.025, 0.05, 0.1, and 0.2 g·mL^-1 saponin, respectively was given to the mice of Groups Ⅰ, Ⅱ, Ⅲ, Ⅳ, and Ⅴ, and the remaining group (Control) was given 1 mL normal saline. The test period was 30 days. On the final day of the experiment, red blood cell (RBC), hematocrit (HCT), erythrocyte mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), free hemoglobin (FHb), reticulocyte count (RET), maximum osmotic fragility of red blood cells (OF_max) and minimum osmotic fragility of red blood cells (OF_min) were measured. Blood and bone marrow were collected to observe blood smear and bone marrow smear while heart and liver slices were made. The results show: 1) After intragastric administration of alfalfa saponins, RBC and HCT were decreased with values for Group Ⅴ being significantly lower than those of the control group (P<0.05). MCV was elevated compared with the control group, with Groups Ⅳ and Ⅴ being significantly different from the control group (P<0.05). 2) FHb values in Groups Ⅳ and Ⅴ and RET in Group Ⅳ were significantly higher than those in the control group (P<0.01). 3) With increase in the intragastric dose, the red blood cell appearance gradually changed, becoming slightly different in size, darker in color, and abnormal in shape. 4) OF_max was significantly increased (P<0.05) and OF_min sshowed a trend towards increase. 5) The proportion of granulocytes was reduced to varying degrees after gavage, and the erythrocyte proportion was increased. Thus, Granulocyte: erythrocyte ratio decreased markedly and in Groups Ⅳ and Ⅴ became significantly lower than in the control group (P<0.05). Compared with the control group, both OF_max and OF_min in Group Ⅴ differed significantly from the Control mice (P<0.05). 6) Parenchymal organs were not effected after gavage but were easily broken. In summary, a high dose of alfalfa saponins can cause intravascular hemolysis.

Key words: alfalfa saponin, red blood cells, hemolysis, hemoglobin