The Effect of Varied Macrophage Cell Concentration on Tumor Necrosis Factor-α Production in Response to Garlic in the Presence and Absence of Lipopolysaccharide
Authors:Travis Alsky, Melissa Arroyo-Mendoza, Alejandra Garcia, Martha Zamora
Mentor:Nancy Buckley, Professor of Biology, Cal Poly Pomona
Folkloric medicine has had it for thousands of years that garlic’s effect is beneficial for its consumer. Garlic is found to stimulate the production of Tumor Necrosis Factor-alpha (TNF-α), a pro-inflammatory immune-regulatory molecule (cytokine), when in contact with receptors on macrophage cells. This cytokine is readily produced in response to Lipopolysaccharide (LPS). LPS is a component in the cell wall of the gram-negative bacteria E. Coli. In our lab, we have found that garlic both stimulates TNF-α production of murine macrophages as well as amplifies the effect when combined with LPS. The goal of this project was to determine whether the effect of garlic is dependent on cell density. Thus, the murine macrophage cell line J774A.1 was plated at 4 different densities (5x10^5 cells/ml, 2.5x10^5 cells/ml, 1.25x10^5 cells/ml, and 0.625x10^5 cells/ml). Twenty four hours later, the cells were treated with garlic (G) diluted 1:500 (G1:500) in pyrogen free water (PFW), in the absence or presence of LPS. Untreated cells and cells treated with PFW served as controls. Twenty four hours after treatment, cell supernatants were collected and stored at -80oC until analyzed for TNF-α levels by enzyme-linked immunosorbent assays (ELISA). We found that garlic stimulates TNF-α production in the absence and presence of LPS at all cell concentrations tested. This data supports the frequent assumption that garlic is effective in the innate immune system. It is suggested that garlic can prepare the immune system for a quick response as well as aid the immune system during an infection due to the increased amount of TNF-α. This increase is thought not to promote any auto-immune diseases and is seen to be a benefit.