Avaliação in vitro da ação da nanoemulsão e do óleo de Carapa guianensis em macrófagos RAW 264.7

Abstract

The innate immune system is the first line of defense against invading pathogens. Macrophages initiate the innate immune response by recognizing pathogens, phagocytosing them, and secreting inflammatory mediators, serving as a link between the innate and acquired immunity. Cytokines are important mediators of immune responses that allow cells to communicate and activate inflammatory mechanisms to solve the challenge. Inflammation must balance proinflammatory mechanisms, to eliminate the causative agent of the aggression, and anti-inflammatory mechanisms to avoid causing further damage to tissues. In view of this and considering the importance of the recognition of novel immunomodulatory agents, our aim was to investigate the action of oil and nanoemulsion of Carapa guianensis in RAW 264.7 macrophages and its effect on release of the proinflammatory cytokines related action (IL-1􀈕, IFN-􀈖, IL-12 and TNF) and anti- inflammatory action (IL-4, IL-10) and in nitric oxide production. Macrophages RAW 264.7 were incubated with different concentrations of C.guianensis oil and nanoemulsion. One group was stimulated with LPS one hour before contact with oil or nanoemulsion , other group was LPS stimulated one hour after contact with the plant and another group was not stimulated. The experiment was done in triplicate and with two independent repetitions. Supernatants were collected after 24, 48 and 72 hours incubation and cytokine levels were measured using the traditional ELISA method. The nitrite production was determined through Griess Reaction. For cytotoxicity concentrations of C.guianensis, oil and nanoemulsion produced dosedependent effect and also time-dependent. Without LPS stimulation, C.guianensis nanoemulsion reduced the release of TNF-α and oil reduced the release of IL-1􀈕 and IL-4. And both increased the release of IL-12 in these cells. Oil and nanoemulsion of C.guianensis inhibited nitrite production, IFN-􀈖, IL-1􀈕, IL-4 and IL-10 in macrophages RAW-264.7 previously stimulated with LPS indicating inhibitory effect on Th1 and Th2 pathway. When stimulated with LPS after contact with the plant, treatment with C.guianensis reduced the release of IFN-􀈖 , IL-1􀈕 and IL-4 in macrophages. These data suggest that the components of oil and nanoemulsion of C.guianensis have predominantly inhibitory effect on the release of cytokines and nitrite production in macrophages.