Preclinical trial of the antitumoral therapeutic effectiveness of some natural polyphenolic biopreparations.

We have assessed the antitumoral action of the POLYAS I and POLYAS II vegetal polyphenolic biopreparations--separated and purified from Asclepias syriaca leaves - in rats with various experimental tumoral lines. We studied the therapeutic effect of different doses on the tumor generation process and compared it with the experimental oncostatic action of several standard chemotherapeutic drugs of clinical use (thiotepa, methotrexate, melphalan and cyclophosphamide). In our experimental treatment with the bioactive polyphenolic agents, we have used various doses, both higher and lower than the dose that had conditioned the expression of their antitumoral action upon Guerin T-8 lymphotropic epithelioma and upon Walker 256 carcinosarcoma. We found the antineoplastic effectiveness of those aromatic biopreparations from phytomass to be dose-dependent. We compared the evaluation indices of the antitumoral pharmacodynamic effect we obtained in the treatment with the POLYAS biopreparations with those of reference cytostatic agents. The antitumoral potential of the new natural biopreparations is higher than, equal or close to that of the standard oncochemotherapeutic agents. Antitumoral effectiveness can be improved by an experimental manipulation of the therapeutic doses--which proves the existence of a dose-response relationship. POLYAS I and POLYAS II polyphenolic biopreparations are compatible in point of effectiveness with the standard cytostatic agents, a fact that we considered relevant for the characterization of the POLYAS I and POLYAS II vegetal extracts as potential antineoplastic agents. The quantitative preclinical evaluation of the specific pharmacodynamic effect will be complemented by the investigation of the new polyphenolic biopreparations therapeutic effectiveness in tumors with various degrees of development.

Preclinical qualitative evaluation of the antitumoral pharmacodynamic action of some natural polyphenolic biopreparations.

We have investigated the impact of POLYAS I and POLYAS II polyphenolic biopreparations - specifically separated and purified from Asclepias syriaca leaves, and characterized in vitro as cytotoxic and/or cytostatic agents - on the tumor generation process. A series of in vivo tests of their effect on the development of Guerin T-8 lymphotropic epithelioma and Walker 256 carcinosarcoma were conducted. In a first stage of preclinical trial we had used several tests meant to evaluate their antitumoural activity indices. The same tests were then used under similar experimental conditions in the solid tumoral systems mentioned. A comparative analysis of the antitumoral activity evaluation indices resulting from our tests with the reference indices set by the American and German preclinical screening programs pointed to their compatibility. Thus, we found similar values of mean tumoral regressions, of the ratio between mean tumoral weights of the treated and control groups, respectively, of the T/C products resulting from successive re-tests. Also T/C values resulting from retests were within the limits of admissible variability range. All those results highlighted the antineoplastic pharmacotherapeutic effect of the polyphenolic biopreparations and also proved that effect to be replicable. The qualitative evaluation of the pharmacodynamic action of those preparations was a condition for their further quantitative pharmacological evaluation in point of antitumoral therapeutic effectiveness in a preclinical stage.

Reactivity of HeLa tumoral cells under the in vitro action of some aromatic compounds from the phytomass.

The in vitro action of some natural polyphenolic preparations, extracted from the leaves of Asclepias syriaca, upon the proteinosynthesis of HeLa cancerous cells and, implicitly, upon the development of HeLa cells cultures was investigated. The significant perturbation of proteic biogenesis, the inhibition of HeLa tumoral cells cultures development, as well as the existence of a dose--response relationship argue the behaviour of these products as in vitro active cytostatic agents. This characterization justifies their introduction in the in vivo screening program on rats bearing of different experimental tumoral lines, for the preclinical pharmacological evaluation of the POLYAS I and POLYAS II vegetable polyphenols antineoplastic activity.