Effect of Crotalus durissus terrificus (Laurenti, 1768) venom on the evolution of Ehrlich ascites tumor

The effect of Crotalus durissus terrificus (LAURENTI, 1768) venom on the evolution of Erlich ascites tumor cells was evaluated. Thus, 30-day-old male mice of the Swiss strain were inoculated intraperitoneally with 1x103 tumor cells. Then, 7 groups of animals were formed: 3 control groups (physiological, venom and tumor) and 4 experimental groups that received different doses of venom. The experimental groups received 5 intraperitoneal venom injections on the 1st, 4th, 7th, 10th and 13th days after tumor implantation. On the 14th day, 5 animals from each one og the groups were sacrificed, and the varibles such as the total and differential counts of cells in the peritoneal cavity and functional state of peritoneal macrophages by macrophage spreading were evaluated. The other 5 remaining animals were kept in the laboratory for 60 days for observation of their survival percentage. The results obtained were statistically analysed by the Kruskal-Wallis test at 5 per cent significance level. It was observed that Crotalus durissis terrificus venom increases survival time of mice, but does not increase mortality percentage. This venom also increases the percentage of macrophage spreading. We suggest that snake venoms can cause inhibition of tumor growth by activating the inflammatory reaction, mainly the macrophages, stimulating the production of TNF-alpha, IL-1, IL-6 and IL-8. These cytokines may act on tumor cells by different mechanisms, inducing its complete elimination.

Isolation of fungi from nature in the region of Botucatu, State of Sao Paulo, Brazil, an endemic area of Paracoccidioidomycosis

In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplement with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25º and 37ºC. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P.brasiliensis. In addition, 98 dematiaceous fungi and 581 different soecies of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.

Antitumor effect of snake venoms

The search for biological antitumor agents has been pursued for over half a century. Snake venom has been shown to possess a wide spectrum of biological activities. The objectives of the present review are to evaluate the existing controversies on this subject published in a number of papers and to propose probable explanations for the phenomena observed. We reported our results obtained in a study, in which we evaluated the action of the venoms of Crotalus durissus terrificus and Bothrops jararaca on Ehrlich ascites tumor cells. We noticed an important antitumor effect, mainly with Bothrops jararaca venom, as well as an increase in the functional activity of macrophages. We also observed an increase in the number of mononuclear and polymorphonuclear cells with Bothrops jararaca venom. Considering these findings, we postulate that both Bothrops jararaca and Crotalus durissus terrificus venoms can act directly on tumor cells. In addition, we propose an indirect mechanism, based on the stimulation of the inflammatory response, to inhibit tumor growth and to promote its rejection.