[Application of flow cytometry on functional assessment of health food]

To establish flow cytometry (FCM) methods and evaluate their application value for measuring the index for enhancing immune function of health food.

In mice experiment model, the dosage groups were respectively oral fed with three test substances according to 5, 10, 30 times of the recommended dose for human body; both the negative and positive control groups were fed with equivalence purified water once a day. The positive control was fed with 25 mg/kg body weight levamisole for 3 days before finishing the administration, and the immune two percent of sheep erythrocytes were administrated at the last day. In rats experiment model, the test substance was given by mixing feed according to 25 and 50 times of the recommended dose for human body. At the end of the experiment, indices below were simultaneously detected. (1) The classical indices included: spleen lymphocyte transformation test by using ConA (MTT assay); spleen NK cell activity test (LDH assay); delayed-type hypersensitivity test by using sheep erythrocyte (foot palm thickening) method and phagocytosis activity tested by mice peritoneal macrophages. (2) FCM indices included: T and B lymphocytes quantitating in mice peripheral blood, activated antigen expression level in the surface of T lymphocytes and NK cells and phagocytosis activity for fluospheres in mice peritoneal macrophages.

(1) Compared with the negative control group, there were no significant differences in T and B lymphocytes proportion and the number of lymphocytes in mice peripheral blood after given 0.83, 1.67, 5.01 g/kg protein powder; (2) mice peripheral blood T lymphocyte sub-cluster CD(69)(+)/CD(3)(+) of 3.75, 7.50, 15.0 ml/kg bw Cen-Rong Cream groups were all significantly increased (P < 0.05), which were shown a good coherence with the classic test index; (3) mice peripheral blood NK cell sub-cluster CD(69)(+)/NKG2D(+) of 0.83, 1.67 g/kg protein powder groups were both significantly increased (P < 0.05), which was kept in good coherence with those of NK cell activity test (LDH assay); rats peripheral blood NK cell sub-cluster CD(161a+)/CD(25)(+) of 1.50 g/kg ganoderma lucidum and cordycepicmycelia group was significantly increased (P < 0.05); (4) the phagocytosis activity in mice peritoneal macrophages: there were no significant difference found between the controls and the dosage groups in the classic test. However, in the FCM test, the percentage of phagocytic cells of 0.15, 0.30, 0.90 g/kg ganoderma lucidum and cordycepicmycelia groups and the phagocytic index of 0.30, 0.90 g/kg were enhanced.

It suggests that was shown in detecting and assessing enhancing immune function of health food the results tested by FCM were fairly consistent with those by using traditional methods, most of them would have higher sensitivity. It should be valuable to applying FCM in the measurement and assessment of enhancing immune function of health food and worth while to further study as to enlarging its application.