Objective: To study the effect of conventionally prepared rabbit serum, usually used in the field of serum pharmacology of TCM, in various concentration on cultured system of human umbilical vein endothelial cell (VEC)-304 cell line.
Methods: Prepared conventionally from healthy rabbit, the effect of uncontaminated and nonhemolytic serum of six concentrations (5%, 10%, 20%, 40%, 60% and 80%) on VEC-304 cells was observed using parameters such as cell morphologic examination, trypan blue exclusion test, methyl thiazolyl tetrazolium (MTT) test, lactate dehydrogenase (LDH) and angiotensin-converting release test.
Results: Serum of 5% and 10% concentration showed no effect in all the above-mentioned tests. Serum of 20% concentration also showed no effect in the tests except for LDH releasing (P < 0.01). But when the concentration of serum reached up to 40% or above, distinct cytotoxicity and serious injury appeared in a dose-dependent manner.
Conclusion: High concentration of conventionally prepared rabbit serum could injure the incubated cell. Therefore, in order to lower the background effect of serum as far as possible in TCM serum pharmacological study, the cytotoxicity of rabbit serum should be tested first of all.