Microcalorimetric study of the opposing effects of ginsenosides Rg1 and Rb1 on the growth of mice splenic lymphocytes

Splenic lymphocytes play an important role in host acute or chronic diseases. The abnormality of these cells in the spleens of humans might lead to some riskful diseases for human. Hence, in this study, the effects of two ginsenosides Rg(1) and Rb-1 on splenic lymphocytes growth were studied by microcalorimetry. Some qualitative and quantitative information, such as the metabolic power-time curves, growth rate constant k, maximum heat-output power of the exponential phase P (max), total heat output Q (t) of splenic lymphocytes were obtained to present the effects of Rg(1) and Rb-1 on these cells. The values of k, P (max), and Q (t) from the thermogenic growth curves of splenic lymphocytes were found to increase in the presence of Rg(1), while the change was adverse for Rb-1, illustrating that Rg(1) had promotion effect and Rb-1 had inhibitory effect on splenic lymphocytes growth and these promotion or inhibitory effects were enhanced with increasing the concentration of the two compounds, respectively. The microcalorimetric results were confirmed by MTT assay for determining the MTT optical density (OD) value and [H-3] Thymidine incorporation assay ([H-3]-TdR) for determining the count per minute (cpm) value: Rg(1) could increase the MTT OD value and the cpm value of [H-3]-TdR incorporation into splenic lymphocytes, and these values were increased with increasing the concentration of this compound, while Rb-1 had the adverse results. The structure-activity relationships showed that the glucopyranoside and hydroxyl groups at the dammarane-type mother nucleus skeleton might play a crucial role for the opposing effects of the two ginsenosides on splenic lymphocytes. Compared with the other two assay methods, the microcalorimetric method provided more useful and reliable information for quickly and objectively evaluating the effects of drugs or compounds on the living cells, which would be a highly promising analytical tool for the characterization of the biological process and the estimation of the drugs' efficiency.