Anti-inflammatory action of geopropolis produced by stingless bees on human peripheral blood mononuclear cells.

Natural products have been used to treat inflammatory reactions and led to the discovery of new anti-inflammatory drugs. Geopropolis (GEO) is produced by stingless bees and has been used by indigenous people to improve the immune functions. Here, a possible synergism between GEO and dexamethasone (DEX) was assessed on human peripheral blood mononuclear cells (PBMC) stimulated by lipopolysaccharide (LPS). PBMC viability was evaluated by the MTT, apoptosis/necrosis by flow cytometry, cytokine and eicosanoids production by ELISA, and intracellular pathways by polymerase chain reaction. GEO and DEX alone or in combination did not affect cell viability. GEO in combination with lower concentrations of DEX inhibited cytokine production (TNF-α, IL-1ß, and IL-10). No effects were seen on eicosanoids nor in intracellular pathways. Despite not always being more efficient than the isolated treatments, GEO + DEX seemed to be promising and allow the use of DEX in lower concentrations, reducing adverse effects.

How Does Brazilian Green Propolis Act in Normal and Tumor Cells? Identification of Compounds in or out Monocytes or HEp-2 Cells.

The aim of this study was to identify propolis compounds after incubation of normal and tumor cells (monocytes and HEp-2 cells, respectively) with Brazilian green propolis, in the lysate and supernatant of cell cultures and within these cells by gas chromatography-mass spectrometry (GC/MS). Cinnamic acid derivatives were generally localized in the lysate of both cell lines after incubation, suggesting these compounds are actively transported across the membrane into the cytoplasm. Terpenes were also found in the lysate. Artepillin C, in contrast, was localised only in the supernatant. Some constituents were unobservable after incubation, especially in monocytes, suggesting the compounds had been degraded. Our findings shed light on the possible sites of action (intracellular or via a cell membrane protein) and the bioavailability of various constituents of propolis, as well as possible modes of delivery of bioactive constituents.

Mechanisms underlying the cytotoxic effect of propolis on human laryngeal epidermoid carcinoma cells.

Propolis has been used as a traditional remedy for centuries because of its beneficial effects, including anticancer properties. The aim of this study was to compare the cytotoxic mechanism of Cuban red propolis (CP) and Brazilian green propolis (BP) on human laryngeal carcinoma (HEp-2) cells. Cell viability, leakage of lactate dehydrogenase, fluorescence staining, mitochondrial membrane potential (ΔΨm) and the expression of pro/anti-apoptotic genes were assessed. Cell viability and cytotoxic assays suggested a dose-dependent effect of CP and BP extracts with a possible association of intracellular reactive oxygen species production and decreased ΔΨm. Both samples induced apoptosis via activation of TP53, CASP3, BAX, P21 signalling, and downregulation of BCL2 and BCL-XL. CP exerted a higher cytotoxic effect than BP extract. Our findings suggest further investigation of the main components of each propolis sample, what may lead to the development of strategies for the treatment of laryngeal cancer.