Antitumor activity of polysaccharides obtained from guavira fruit industrial waste on murine melanoma cells

Melanoma is an aggressive type of cancer with increasing incidence worldwide. Chemotherapy drugs are associated with several side effects that lead to lost quality of life for patients undergoing treatment. This fact has encouraged the search for compounds capable of acting as adjuvants in cancer treatment with fewer side effects. Pectins are soluble polysaccharides with diverse molecular structures and important biological properties, which can be obtained from fruit parts often discarded by the food industry. The present study investigated the antitumor effect of pectins present in guavira pomace flour (Campomanesia adamantium and C. pubescens) on B16F10 cells. The assays evaluated viability, cell death, proliferation rate, migratory ability, and potential for colony formation. The results showed that pectins (CPW fraction) at concentrations of 5 and 100 μg/mL reduced the viability of tumor cells (∼20–40%, respectively, when compared to the untreated group), with less cytotoxicity on non-tumor cells (BALB/c 3T3) than the chemotherapy drug Doxorubicin (p < 0.05). Similarly, the proliferation rate was decreased in B16F10 cells in the presence of two CPW concentrations (∼33 and 40%, respectively). In the flow cytometry assay, the CPW treatment did not increase the number of dead cells, suggesting cell cycle arrest. In addition, the CPW fraction reduced the migratory capacity of tumor cells (∼8 and 12%, respectively) and the number of new colonies formed (∼30 and 70%, respectively). Taken together, these results suggest that the pectins of guavira pomace flour, a discarded industrial material, have important antitumor activity with adjuvant therapeutic potential for cancer treatment.