Extracts of Pumpkin (Cucurbita pepo L.) Seeds Suppress Stimulated Peripheral Blood Mononuclear Cells in vitro

In the traditional medicine in North America and Mexico, pumpkin seeds have been used as an anthelmintic agent and for supportive treatment in functional disorders of the bladder. Also anti-inflammatory and cardioprotective activity of pumpkin seeds is discussed. Three different extracts of pumpkin seeds were prepared and effects were investigated in unstimulated human peripheral blood mononuclear cells and in cells stimulated with the mitogens phytohaemagglutinin and concanavalin A in vitro. Tryptophan degradation and neopterin concentrations were measured in the supernatants allowing to detect biochemical changes induced by cytokine interferon-γ. Extracts of pumpkin seeds suppressed mitogen-induced neopterin production and tryptophan degradation in a dose-dependent way. Data demonstrate capacity of pumpkin extracts to modulate immunobiochemical pathways induced by interferon- γ. Findings imply an immunoregulatory potential of compounds contained in pumpkin seeds.