The role of humoral factors of regenerating liver in the development of experimental tumors and the effect of Rhodiola rosea extract on this process.

In experiment on rats with Pliss lymphosarcoma (PLS) it was shown that partial hepatectomy (PHE), a course application of Rhodiola rosea extract (RRE) or combined effects inhibit the growth of tumors by 37, 39 and 59%, respectively, and that of metastases by 42, 50 and 75%. In combined treatment the process of hepatic regeneration was completed in earlier terms versus the animals which underwent PHE, and proliferative activity of the tumor and metastases decreased by 15 and 59%, respectively, judging by the degree of 3H-thymidine incorporation into DNA of these tissues. The assessment of clonogenic activity of PLS cells taken in the animals of this group, using the method of diffusion chambers, revealed a significant decrease in this index versus the rats which underwent PHE or which were given RRE (number of colonies per chamber being 4.8 +/- 0.5; 8.6 +/- 0.9; 5.7 +/- 0.6, respectively; in control 13.8 +/- 1.5). The assumption that these effects are determined by factors originating from the regenerating liver was confirmed in experiments with double-layer agar systems. Inhibition of colony-forming activity of PLS cells was the maximum in application of the hepatocytes of the rats which underwent a complex of effects, as a feeder, versus the hepatocytes taken in intact or hepatectomized animals, or the rats which were given RRE (number of colonies per plate well being 4.6 +/- 0.3; 15.7 +/- 1.6; 7.4 +/- 0.8; 8.7 +/- 0.9, respectively; in the control 25.6 +/- 6.5). In experiments on mice with Ehrlich adenocarcinoma, the factors isolated from the liver of animals subjected to PHE against a background of RRE administration and from the liver of mice which were given RRE only, as well as operated or intact ones, inhibited the tumor growth to 63, 38, 35 and 21%, respectively.