Effects of uncaria tomentosa on the growth and survival of B16-BL6 mouse melanoma cells

Abstract

Uncaria tomentosa is a medicinal plant native to Peru that has been traditionally used in the treatment of various disorders, including cancer. U. tomentosa is one of the best-selling herbs in the world and is used as an immunomodulatory, anti-inflammatory and anti-cancer remedy. This study assessed the effectiveness of U. tomentosa on the growth and survival of B16-BL6 mouse melanoma cells. Both ethanol and PBS extracts of U. tomentosa extracts were tested in vitro and in vivo in order to evaluate their potential anticancer activity. In addition, different methods to measure the effect of treatment were used, including MTT assay, immunofluorescence (Ki67 protein and TUNEL assay) and the isogenic tumour transplantation model. The present results showed that U. tomentosa significantly inhibited cell proliferation and induced morphological changes in vitro. Furthermore, U. tomentosa was able to increase the percentage of apoptotic cells in a concentration-dependent manner. There was also decrease in the expression of Ki-67 (cell proliferation marker). Two experiments were performed to assess the ability of U. tomentosa to inhibit B16-BL6 cell growth in vivo. Mice were injected subcutaneously (on the top of the muscle) with B16-BL6 cells and tumours were allowed to progress for two weeks. In some animals, U. tomentosa extracts were injected intraperitoneal and intratumour. The animals were sacrificed and tumour diameters and weights were measured. The results showed that U. tomentosa caused a significant reduction in tumour weight but the tumor size was not significantly affected when compared to the controls. Interestingly, there were no significant differences in mouse weight for all treated groups. Overall, U. tomentosa showed promising results and caused a marked reduction in B16-BL6 melanoma cell growth.