Efeito protetor de uma proteína isolada da semente de Morinda citrifolia L. na mucosite intestinal induzida por irinotecano em camundongos

Abstract

Intestinal mucositis (IM) is a side effect that can affect patients who are being treated for colorectal cancer (CRC). About 85% of patients undergoing chemotherapy develop MI in varying degrees and the available treatment is only palliative. Morinda citrifolia L., commonly known as noni, is a species native to Southeast Asia, also found in northeastern Brazil, especially in the states of Sergipe and Ceará, used medicinally for the treatment of cancer, infections, inflammation and pain. Our research group has demonstrated that McLTP1, a lipid transfer protein isolated from the seeds of M. citrifolia, presented antiinflammatory, gastroprotective, antibacterial and antinociceptive activity in mice. The objective of this study was to study the effect of McLTP1 on the intestinal mucositis model induced by irinotecan (CPT-11). For induction of IM male swiss mice (25-30 g) were divided into 5 groups: group 1 received saline (0.9%, i.p.) once daily for four days; Group 2 received irinotecan (75 mg/kg, i.p.) once daily for four days; Groups 3, 4 and 5 were treated for 7 days with McLTP1 at doses of 0.5 mg/kg, 2 mg/kg and 8 mg/kg e.v. respectively, 30 min before CPT-11 which was administered for 4 days. During the seven days the weight loss, presence of diarrhea by scores and the survival were evaluated. On the seventh day, blood was collected for leukocyte count and then euthanasia for duodenum collection and evaluation of the following parameters: small intestine length, intestinal contractility, histopathological and morphometric changes, MPO, GSH, MDA, NO, cytokines (IL-1β, IL-6, KC, TGF-β and IL-10) and the immunohistochemistry for COX-2, NFκB and iNOS. Statistical analysis used ANOVA/Bonferroni or Kruskal Wallis/Dunns test and p <0.05 was considered significant. This study was approved by the UFC - CEPA Animal Research Ethics Committee (93/15). CPT-11 caused loss of body mass, diarrhea, increased mortality, induced leucopenia, decreased intestinal length, increased intestinal contractility, caused villyl flattening, loss of crypt architecture, presence of vacuolization, inflammatory cell infiltrate, and mucous and muscular layer. An increase in the levels of MPO, IL-1β, IL-6, KC and TGF-β was observed in relation to inflammatory parameters, in addition to increased immunohistochemistry for COX-2, NFκB and iNOS. An increase in MDA and a decrease in GSH levels were also observed. Comparatively, treatment with McLTP1 8 mg/kg reduced diarrhea, increased survival, prevented intestinal length reduction, decreased hypercontractility and intestinal damage, attenuating the histopathological changes caused by CPT-11. McLTP1 was also able to decrease the levels of MPO, IL-1β, IL-6, KC and TGF-β, decrease the immunostaining for COX-2, NFκB and iNOS, and decrease MDA levels and increase GSH. Therefore, McLTP1 demonstrates important anti-inflammatory and antioxidant activities that make it a promising therapeutic option to prevent and attenuate the severity of intestinal mucositis during the chemotherapy treatment with CPT-11.