Acute toxicity study of bioactive galactomannans from seeds of two nontraditional leguminosae

Abstract

Non-traditional galactomannans sources are widely cultivated in the Brazilian Northeast Region, such as the species Caesalpinia pulcherrima (peacock flower) and Delonix regia (flamboyant). The galactomannans GM-CP and GM-DR were extracted from the respective seeds and are being studied as potential therapeutic agents, but systematic evaluations on their acute toxicity are yet to be reported. Groups of three female rats received oral GMCP or GM-DR (300 mg kg-1), whereas a control group received vehicle (saline). Since there was no lethality, other groups received doses of 2000 mg kg-1, which also did not cause lethality. Organs and blood samples were collected on day 14. Mechanical hypernociception and inflammatory cell influx were measured in other groups receiving intra-articular doses of GM-CP or GM-DR (200 µg, n = 5 per group). Neither galactomannan evoked physiological / behavioral changes or joint inflammation. Since the LD50 was less than 2000 mg kg-1, such polysaccharides may be allocated in the class 5 of the Globally Harmonized System for Classification and Labelling of Chemicals.