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Lichens are sources of numerous biologically active compounds and many of these have demonstrated antitumor potential. The purposes of this study were to evaluate the antiproliferative activity and selectivity of the following compounds isolated from lichens: atranorin and diffractaic, divaricatic, perlatolic, psoromic, norstictic, and protocetraric acids. Cytotoxicity tests based on sulforhodamine B were performed on normal cells (NIH/3T3, fibroblast) and cancer cell lines 786-0 (renal), MCF7 (breast), HT-29 (colon), PC-3 (prostate), and HEp2 (laryngeal). Diffractaic acid exhibited GI50 values in the 58.6-98.9 µM range. Divaricatic and perlatolic acids were the most active compounds, with GI50 values of 9.8 and 15.5 µM for PC-3 and MCF7 cells, respectively. Protocetraric acid proved active only against HEp2 cells (GI50 = 41.4 µM). Atranorin, psoromic acid, and norstictic acids were inactive against all the cells tested. Chemometrics was used to evaluate the effect of the compounds against the cell lines tested. PCA (Principal Component Analysis) based on GI50 values separated compounds into two groups compared to doxorubucin, while HCA (Hierarchical Cluster Analysis) separated them into three groups based on SI values. [ABSTRACT FROM AUTHOR]

Topical administration of powdered shells of the land snail Megalobulimus lopesi was evaluated in Wistar rats for their healing activity in an excision wound model. The animals were distributed into three groups-G1 (control): no therapeutic intervention; G2 (vehicle controls): Lanette cream once daily; G3 (experimental animals): treated with powdered shells. Variables investigated were: wound area contraction, angiogenic activity, morphometric data, leukocytic inflammatory infiltrate, and total leukocyte count in peripheral blood. Thermogravimetric analysis and quantification and characterization of powdered shell proteins were also performed. Wound area on days 3, 7, and 14 was smaller in G3, besides presenting wound closure on day 21 for all these animals. Topical administration of the powdered shells also led to an increased number of vessels at the wound site, higher leukocyte counts in peripheral blood, and increased leukocytic inflammatory infiltrate. The results lend support to the southern Brazilian folk use of M. lopesi powdered shells, as shown by the enhanced secondary-intention healing achieved with their topical administration to wounds in rats. Topical administration caused inflammatory response modulation, crucial to accelerating the healing process, the chronification of which increases the risks of wound contamination by opportunistic pathogens.