Copaifera spp. oleoresins impair Toxoplasma gondii infection in both human trophoblastic cells and human placental explants

Abstract

The combination of pyrimethamine and sulfadiazine is the standard care in cases of congenital toxoplasmosis. However, therapy with these drugs is associated with severe and sometimes life-threatening side effects. The investigation of phytotherapeutic alternatives to treat parasitic diseases without acute toxicity is essential for the advancement of current therapeutic practices. The present study investigates the antiparasitic effects of oleoresins from different species of Copaifera genus against T. gondii. Oleoresins from C. reticulata, C. duckei, C. paupera, and C. pubiflora were used to treat human trophoblastic cells (BeWo cells) and human villous explants infected with T. gondii. Our results demonstrated that oleoresins were able to reduce T. gondii intracellular proliferation, adhesion, and invasion. We observed an irreversible concentration-dependent antiparasitic action in infected BeWo cells, as well as parasite cell cycle arrest in the S/M phase. The oleoresins altered the host cell environment by modulation of ROS, IL-6, and MIF production in BeWo cells. Also, Copaifera oleoresins reduced parasite replication and TNF-α release in villous explants. Anti-T. gondii effects triggered by the oleoresins are associated with immunomodulation of the host cells, as well as, direct action on parasites.

Cyclooxygenase (COX)-2 modulates Toxoplasma gondii infection, immune response and lipid droplets formation in human trophoblast cells and villous explants

“…In this sense, combining our findings with literature, we hypothesized that the reduction in TNF-α levels, as result of COX-2 inhibition, may culminate in a decrease of PGE 2 production by infected villous, which could explain the impairment of the parasite growth. Taken together, in agreement with published studies, our data reveal a different cytokine profile between human trophoblast cells and villous explants from human third trimester pregnancy in the context of T. gondii 56 , 57 , 60 . In this context, we suggested that these differences among both models may be explained, in part, due to the fact that human villous is a tissue composed of mesenchyme, villous and extravillous trophoblast and syncytiotrophoblast, culminating in a distinct cytokine production.…”

“…Additonally, BeWo cells and HTR-8/SVneo showed below detection levels of IL-8, TGF-β1, and TNF, or IL-8, TNF and IL-10, respectively. Regarding to T. gondii infection in experimental models of maternal–fetal interface, previous studies also have reported, by ELISA assay, undetectable levels of TGF-β1, IL-12p70, TNF-α, and IFN-γ cytokines produced by BeWo cells, even after parasite infection 56 , 57 . In addition, a weak expression of IL-8 is commonly observed in unstimulated BeWo cells 72 .…”

“…Furthermore, the MTT assay was performed on the villous 57 , 92 , 95 . After 24 h of treatment, the supernatants were collected and frozen at -80 °C for later measurements of cytokines.…”

“…Data were expressed in pg/mL according to a standard curve of each cytokine for BeWo and HTR-8/SVneo cells, while for villous explants, the data were normalized according to the protein concentration of each villous. Then, for villous explants, the data about cytokines were obtained by the ratio between concentration of cytokines in pg/mL and concentration of total protein from Bradford assay in µg/mL, resulting in pg/mg of tissue 56 , 57 , 91 .…”

“…Additionally, we also evaluated the functional role of COX-2 in the immune response and lipid droplets formation in these experimental models. Our research group has investigated the mechanisms of T. gondii infection in trophoblast cells using BeWo 54 – 57 and HTR-8/SVneo 58 – 60 cell lines as villous and extravillous trophoblast cells models, respectively, and human chorionic villous explants as maternal–fetal interface experimental model 56 , 60 – 62 .…”