Red Angico Gum: A Nontoxic Polysaccharide with Promising Antitumor and Antiedematogenic Activity

Polysaccharides are complex carbohydrates that play essential roles in several biological processes. The aim of this study was to isolate, characterize, and evaluate the cytotoxic, antitumor, and antiedematogenic potential in vitro and in vivo of red angico gum (RAG), a polysaccharide isolated from Anadenanthera colubrina var. cebil (Griseb.) Altschul. To confirm the chemical characteristics of RAG, nuclear magnetic resonance, size-exclusion chromatography, high-performance liquid chromatography analysis, and determination of uronic acid content by potentiometric titration were performed. RAG is composed mainly of arabinose and galactose with smaller proportions of rhamnose and glucuronic acid. In vitro cytotoxicity was determined by MTT and Alamar blue assays. For in vivo assays, mice bearing a sarcoma 180 tumor and the carrageenan-induced paw edema model were used to evaluate the antitumor and antiedematogenic effects. Hematological, biochemical, histopathological, and mutagenic analyses were performed to observe signs of toxicity after RAG administration. RAG did not show cytotoxicity in vitro; in contrast, it showed a significant tumor inhibition in vivo of up to 46.5%. Notably, such effects were observed without causing systemic and tissue toxicity in animals. Furthermore, RAG administration significantly reduced paw edema. These findings suggest that this polysaccharide exhibits antitumor and antiedematogenic potential in animal models, without showing signs of toxicity.