Chemotherapeutic and Safety Profile of a Fraction from Mimosa caesalpiniifolia Stem Bark.

Mimosa caesalpiniifolia (Fabaceae) is used by Brazilian people to treat hypertension, bronchitis, and skin infections. Herein, we evaluated the antiproliferative action of the dichloromethane fraction from M. caesalpiniifolia (DFMC) stem bark on murine tumor cells and the in vivo toxicogenetic profile. Initially, the cytotoxic activity of DFMC on primary cultures of Sarcoma 180 (S180) cells by Alamar Blue, trypan, and cytokinesis block micronucleus (CBMN) assays was assessed after 72 h of exposure, followed by the treatment of S180-bearing Swiss mice for 7 days, physiological investigations, and DNA/chromosomal damage. DFMC and betulinic acid revealed similar in vitro antiproliferative action on S180 cells and induced a reduction in viable cells, induced a reduction in viable cells and caused the emergence of bridges, buds, and morphological features of apoptosis and necrosis. S180-transplanted mice treated with DFMC (50 and 100 mg/kg/day), a betulinic acid-rich dichloromethane, showed for the first time in vivo tumor growth reduction (64.8 and 80.0%) and poorer peri- and intratumor quantities of vessels. Such antiproliferative action was associated with detectible side effects (loss of weight, reduction of spleen, lymphocytopenia, and neutrophilia and increasing of GOT and micronucleus in bone marrow), but preclinical general anticancer properties of the DFMC were not threatened by toxicological effects, and these biomedical discoveries validate the ethnopharmacological reputation of Mimosa species as emerging phytotherapy sources of lead molecules.

Synthesis of novel α-santonin derivatives as potential cytotoxic agents.

Ten novel α-santonin derivatives have been synthesized as cytotoxic agents. The in vitro antitumor activity of these compounds has been evaluated against cancer cells lines. Structure-activity relationships indicate that α-methylene-γ-lactone and endoperoxide functionalities play important roles in conferring cytotoxicity. The compounds 2-4, possessing the α-methylene-γ-lactone group showed IC50 values between 5.70 and 16.40 µM. Mixture of isomers 5 and 6, with the α-methylene-γ-lactone and endoperoxide functionalities, displayed the greatest activity, with IC50 values between 1.45 and 4.35 µM. The biological assays conducted with normal cells revealed that the compounds 2, 5 and 6 are selective against cancer cells lines tested. Bioactive lactones described herein and in our previous report did not cause disruption of the cell membrane in mouse erythrocytes.