OBJECTIVETo observe monocyte (Mo) development in wild type C57BL/6 mice and apoE gene knockout (apoE(-/-)) mice, and to evaluate the immuno-regulatory effect of Huanglian Jiedu Decoction (HJD) on peripheral Mo development in apoE(-/-) mice.

METHODSFour, 8, 12, and 16 weeks old female C57BL/6 mice were set up as control groups of different ages, while 4, 8, 12, and 16 weeks old female apoE(-/-) mice were set up as hyperlipidemia groups of different ages. Four-week old female C57BL/6 mice were recruited as a blank group. Four-week old female apoE(-/-) mice were randomly divided into the control group, the Western medicine group, and the Chinese medicine group by paired comparison, 5 in each group. Equivalent clinical dose was administered to mice according to body weight. Mice in the Western medicine group were administered with Atrovastatin at the daily dose of 10 mg/kg by gastrogavage, while those in the Chinese medicine group were administered with HJD at the daily dose of 5 g/kg by gastrogavage. Body weight was detected each week. After 4 weeks blood lipids levels (such as TG, TC, LDL-C, and HDL-C), and the proportions of Mo and Ly6c(hi) were detected.

RESULTSCompared with 4-week-old homogenic mice, the proportion of Mo decreased in 16-week-old C57BL/6 mice (P < 0.05). Levels of TC and TG, and the proportion of Ly6c(hi) subtype increased, but the proportion of Mo de- creased in 8-week-old apoE(-/-) mice (P <0. 05). Levels of TC, TG, and LDL-C increased in 12-week-old apoE(-/-) mice (P < 0.05). Levels of TC, TG, LDL-C, and HDL-C increased in 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01). Compared with 8-week-old homogenic mice, the proportion of Mo decreased in 16-week-old C57BL/6 mice (P < 0.05); levels of TC and LDL-C increased in 12-week-old apoE(-/-) mice (P < 0.05); levels of TC and HDL-C increased in 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01). Compared with C57BL/6 mice of the same age, TC and TG increased, HDL-C decreased (P < 0.01) in 4-and 8-week-old apoE(-/-) mice (P < 0.01); levels of TC, TG, LDL-C increased, and HDL-C level decreased in 12- and 16-week-old apoE(-/-) mice (P < 0.05, P < 0.01); the proportion of Mo increased in 4-week-old apoE(-/-) mice (P < 0.05); proportions of Mo and Ly6c(hi) increased in 8-week-old apoE(-/-) mice (P < 0.05). Compared with the blank control group, levels of TC, TG, and LDL-C, proportions of Mo and Ly6c(hi) increased (P < 0.01, P < 0.05), but HDL-C level decreased (P <0. 01) in the control group after intervention. Compared with the control group, body weight gained less in the Western medicine group and the Chinese medicine group (P < 0.05); the proportion of Ly6c(hi) subtype decreased in the Chinese medicine group (P < 0.05).

CONCLUSIONSIn development process blood lipids levels in apoE(-/-) mice are not only associated with age. Blood lipids levels induced growth changes in natural immune system are also correlated with age. In early stage of lipids development HJD intervention could correct this special immune disorder in apoE(-/-) mice.