A number of natural compounds have been used as immunomodulatory agents, enabling the function of the immune system to be modified by stimulating or suppressing it. There has been increasing interest in the study of therapeutic action of plant extracts regarding their immunomodulatory activity. The aim of this study was to identify and evaluate the action of extracts of the medicinal plants Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis and Vernonia scorpioides on the development of spleen cells from mice, using the in vitro cellular proliferation assay. The cells, obtained by mechanical rupture of mice spleen (5x10(4) cells/mL), were incubated with methanol extracts (10, 50, 100 and 200 µg/mL) and phytohemagglutinin (PHA, 5 µg/mL). The basal control for proliferation consisted of cells alone, while the positive control consisted of cells and PHA. The cell culture was kept at 37 ºC in 5% CO2 for 72 hours, and cell proliferation was revealed by the blue tetrazolium reduction assay (MTT). The results were expressed as percentage of growth and were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The C. brasiliense, I. pes-caprae and M. elaeagnoides extracts showed dose-dependent induction of cell proliferation, with a significant increase in cell proliferation (p<0.03) and percentage growth of 88.2%, 73.1% and 52.7%, respectively, suggesting T lymphocyte stimulation. By contrast, M. robusta, R. imperialis and V. scorpioides extracts showed significance only with a negative percentage of growth, suggesting inhibition of cell proliferation (p<0.04). Further biomonitoring studies will enable the fractions and isolated substances responsible for the immunomodulatory activities to be identified.
Medicinal plants; Natural products; Immunomodulation; Calophyllum brasiliense; Ipomoea pes-caprae; Matayba elaeagnoides; Maytenus robusta; Rubus imperialis; Vernonia scorpioides
