Estudo do potencial antitumoral in vitro e in vivo de um heteropolissacarídeo extraído do exsudato do caule de Anacardium occidentale L.

Abstract

Cancer is characterized by a group of diseases related to the disordered growth of the cells, which invade tissues and organs. Several new drugs, derived from plants, algae, microorganisms and other sources, have been investigated due to their potential to treat different types of cancer. Polysaccharides extracted from plants have innumerable applications described in the literature, such as antibacterial, antifungal, antioxidant and antitumor activities, in vitro and in vivo. However, the antitumor effects of these polysaccharides are not fully elucidated yet. This study aimed to evaluate the antitumor potential of the cashew gum, through in vitro and in vivo models. The cashew gum did not demonstrate cytotoxic and antimigratory activity in vitro in murine and human tumor cells at the concentration of 100 μg / ml. In vivo assays showed that cashew gum was able to inhibit in 35% and 40% the tumor growth in murine metastatic melanoma (B16F-10), at doses of 50 and 100 mg / kg, respectively. In addition, the polysaccharide does not decrease the weight of the animals, since it is composed basically of sugar chains. Regarding hematological components, cashew gum did not cause leucopenia, and not significant hematological alterations, demonstrating that this polymer does not cause depletion of the immune system of the animal. Histological sections of the organs have shown that cashew gum did not caused toxic lesions in the liver, kidney, lung and spleen. Tumor slices indicated a cell death process indicative of apoptosis in treatment with cashew gum. The analysis of the tumor tissue by FTIR indicated a similar death process in treatments with cyclophosphamide and cashew gum, by the stretching of lipids representative bands, and groups present in the DNA. With regard to the analysis of enzymatic and non-enzymatic antioxidant components (GSH, MDA and MPO), Cashew gum did not indicate the production of these antioxidant agents, possibly demonstrating that this polymer does not cause tissue oxidative stress. Therefore, it is concluded that this polysaccharide could help in the treatment of neoplasias, by possibly reducing the side effects generated by the chemotherapeutic, besides helping in the tumor reduction.