Abstract: OBJECTIVE: To evaluate the potential immunotoxicity of three traditional Chinese medicines:Mailuoning,Shengmai and Danxiangguanxin,in mice using the direct popliteal lymph node assay (D-PLNA) and reporter antigen popliteal lymph node assay (RA-PLNA). METHODS: In D-PLNA,mice were randomly divided into five groups:Mailuoning,Shengmai and Danxiangguanxin,normal saline control and diphenylhydantoin (DPH) positive control. In RA-PLNA,the above groups were combined administration with reporter antigens TNP-Ficoll or TNP-OVA. Mice were randomly assigned to their respective treatment groups,8 in each group and received a subcutaneous injection into left hind footpad with or without RAs in a final volume of 50 μL. At 7 days after injection,mice were sacrificed and popliteal lymph nodes were excised and then grinded to prepare single cell suspensions. Cell number was counted and cell index was calculated. Concentration of IgE and MCP-1 cell supernatant were measured by ELISA assay after cell suspension was cultured with stimulant in a 96-well plate. RESULTS: In D-PLNA,compared with the control group,Danxiangguanxin injection increased PLN cellularity significantly (P < 0.05). In RA-PLNA,each treatment group significantly increased PLN cellularity and the concentration of MCP-1 when co-injected with TNP-Ficoll(P < 0.05). When co-injected with TNP-OVA,Mailuoning stimulated significant secretion of IgE while Danxiangguanxin increased the concentration of IgE and MCP-1(P < 0.05). CONCLUSION: Mailuoning and Shengmai injection only caused positive reaction after RAs were added. This suggests they may contain low molecular weight compounds as hapten to induce type I hypersensitivity reaction. However,the composition of Danxiangguanxin is complex and may directly induce type I hypersensitivity reaction,and may also act as a neo-antigen or neo-epitope to elicit immune response.

Key words: popliteal lymph node assay, traditional Chinese medicine injection, immunotoxicity, low molecular weight compound