Evaluation of acute toxicity of β-lapachone associated with chitosan as a cytoprotective agent

ABSTRACT INTRODUCTION: β-lapachone (β-LAP), a potent antitumor agent, has limited therapeutic use due to its low solubility and high toxicity. A possible strategy to overcome these drawbacks may be the use of adjuvants such as chitosan (CS), a cationic polysaccharide with biological properties of biocompatibility and biodegradability. OBJECTIVE: Evaluate the adjuvant action of CS as a cytoprotectant associated with β-LAP, through acute toxicity studies, evaluating histopathological changes in organs such as liver and kidneys. METHODS: The β-LAP-CS conjugate was prepared in a 1:1 ratio, administered orally, with a single dose of β-LAP of 80 mg/kg, in Swiss mice. Histomorphological and histomorphometric analyses of the kidneys and liver were performed. RESULTS: In the histomorphological studies of the tested groups, we observed that the hepatocytes of animals treated with the free drug presented morphological alterations, such as cytoplasmic vacuolization, cellular extravasation, atypical and pyknotic nuclei. In this same group, the kidneys presented granular aspects suggestive of glomerulonephritis. These changes were not found in the control group and in animals treated with CS-conjugated β-LAP. There was no statistical difference in the histomorphometric analyses of the distal tubules and the renal glomeruli between the three groups analyzed, even with evident histomorphological alterations. After histomorphometric studies, it was observed that the area of hepatocytes and their cell nuclei presented a statistically significant difference between the animals treated with free β-LAP and the β-LAP-CS. CONCLUSION: The decrease in β-LAP toxicity after conjugation may be related to the hepatoprotective property of CS.