RESUMEN
We investigated the mechanism of action of Dendrostellera lessertii effects on decreasing size of adeno-carcinoma of rat intestine and breast tumors. This purpose followed by assessing its effects on TNF-alpha and TNF-alpha receptors on cultured human monocytes. The breast and intestine tumors were induced in rats by DMBA and DMH, respectively. Human monocytes isolated by adhesion procedure. TNF- alpha in cultured media were measured by sensitive biotin-streptoavidin ELISA method and radio iodination was used for TNF- alpha receptors determination on human cultured monocytes. Oral administration of Dendrostellera lessertii extract during 20 consecutive weeks reduced significantly the diameter of tumor or eliminated them totally. Our data indicated that the plant extract at various doses did increase TNF-alpha release and in a time dependent manner decreases the TNF- alpha receptors in less than 90 minutes significantly in cultured human monocytes. Dendrostellera lessertii extract [H2O/EtOH] decreases the size of rat adenocarcinoma breast tumors. Our data support that the extract probably act through increasing TNF-alpha releasing and decreasing TNF-alpha receptors on cultured human monocytes