In vitro and in vivo antitumor effect of 5-FU combined with piplartine and piperine.

It has been reported that piplartine and piperine, alkaloid/amide compounds from Piper species, show antitumor activities. In the present paper, the effects of the combination of 5-fluorouracil (5-FU) with piplartine or piperine was determined using in vitro and in vivo experimental models. Hematological and biochemical analyses, as well as histopathological and morphological analyses of the tumor and the organs, including liver, spleen and kidney, were performed in order to evaluate the toxicological aspects associated with different treatments. The incubation of tumor cell lines with 5-FU in the presence of piplartine or piperine produced an increase in growth inhibition, as observed by lower IC50 values for 5-FU. These effects were also observed in vivo, where the combination with piplartine but not piperine with 5-FU led to a higher tumor growth inhibition. The results indicated that either piplartine- or 5-FU-treated animals showed a low inhibition rate when they were used individually at low doses of 28.67% and 47.71%, respectively, but when they were combined at the same dose, the inhibition rate increased significantly to 68.04%. The histopathological analysis showed that the livers and the kidneys of treated animals were only slightly and reversibly affected. Neither the enzymatic activity of transaminases nor the urea levels were significantly modified when compared with the control group. Hematological analysis showed leukopenia after 5-FU treatment, which was reversed by the combined use of piplartine and piperine. These findings indicate that piplartine may enhance the therapeutic effectiveness of chemotherapeutic drugs, and moreover, this combination could improve immunocompetence hampered by 5-FU.

In vivo growth inhibition of sarcoma 180 by piperlonguminine, an alkaloid amide from the Piper species.

Many authors have already emphasized that phytochemicals from spices have biological applications. Piperlonguminine is a known alkaloid amide from peppers, including Piper divaricatum. The aim of this study was to investigate the in vitro and in vivo antitumor effects of piperlonguminine in experimental models. In order to evaluate the toxicological aspects related to piperlonguminine treatment, hematological, biochemical, histopathological and morphological analyses of treated animals were performed. Piperlonguminine did not show any significant in vitro cytotoxic effect at experimental exposure levels, but showed an in vivo antitumor effect. After 7 days of treatment, the inhibition rates were 38.71% and 40.68% at doses of 25 mg kg(-1) and 50 mg kg(-1), respectively. The histopathological analysis suggests that the liver and kidney were only weakly affected by piperlonguminine treatment. Neither the enzymatic activity of transaminases (AST and ALT) nor the urea levels were significantly altered. In the hematological analysis, all parameters analysed remained constant after piperlonguminine treatment. In conclusion, these data reinforce the anticancer potential of spice components.