Location: Food Components and Health LaboratoryTitle: A single meal containing raw, crushed garlic influences expression of immunity- and cancer-related genes in whole blood of humans
|SOLVERSON, PATRICK - University Of Maryland|
Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2016
Publication Date: 11/1/2015
Citation: Charron, C.S., Dawson, H.D., Albaugh, G.P., Solverson, P.M., Vinyard, B.T., Solano Aguilar, G., Molokin, A., Novotny Dura, J. 2015. A single meal containing raw, crushed garlic influences expression of immunity- and cancer-related genes in whole blood of humans. Journal of Nutrition. 145:2448-2455.
Interpretive Summary: Epidemiology and animal studies show promise for garlic in cancer prevention and protection against cardiovascular disease. However, human study results have been ambiguous. One of the problems may be that the biomarkers we use to measure risk for disease are not closely enough linked to disease outcome. Therefore, we designed a human study of garlic’s activity in the body by using the novel approach of probing the deepest physiologic response, gene expression. The deepest information held in the body is the genome, and when the body responds to an environmental stimulus, the body’s machinery starts at the genome to read information about how to generate new machinery and translates that information into the construction of new proteins. This process is called gene expression. Using the novel approach of studying gene expression in white blood cells of humans, we were able to show how the body responds to garlic intake, focusing on pathways that affect cancer and cardiovascular disease. This approach will not only reveal new mechanisms of garlic action, but will also advance the opportunities for probing the body’s response to nutritional stimuli. This information will be used by scientists.
Technical Abstract: Preclinical and epidemiological studies suggest that garlic intake is inversely associated with the progression of cancer and cardiovascular disease. To probe mechanisms of garlic action in humans, we conducted a randomized crossover feeding trial in which 17 volunteers consumed a garlic-containing meal (100 g white bread, 15 g butter, 5 g raw, crushed garlic) or a garlic-free control meal (100 g white bread, 15 g butter) after 10 days of a controlled, garlic-free diet. Blood was collected before and 3 h after test meal consumption for gene expression analysis in whole blood. Illumina BeadArray was used to screen for genes of interest, followed by real-time qRT-PCR on selected genes. Seven genes were found to be upregulated by garlic intake: AHR, ARNT, HIF1A, JUN, NFAM1, OSM, and REL. Fold-increases in mRNA transcripts ranged from 1.6 (HIF1A) to 3.0 (NFAM1) (P<0.05). To explore the expression of these genes in cell culture, Mono Mac 6 cells were treated with a purified garlic extract (0.5 µL/mL) and mRNA was measured by qRT-PCR at 0, 3, 6, and 24 h. mRNA of 5 of the 7 genes that were upregulated in the human trial were also upregulated in cell culture at 3 and 6 h: AHR, HIF1A, JUN, OSM, and REL. Fold-increases in mRNA transcripts in cell culture ranged from 1.7 (HIF1A) to 12.1 (JUN) (P<0.01). OSM protein was measured by ELISA and was significantly higher than control at 3, 6, and 24 h (24 h, control 19.5 +/-1.4 pg/mL, garlic 74.8 +/- 1.4 pg/mL). OSM is a pleiotropic cytokine which inhibits several tumor cell lines in culture. These data indicate that the bioactivity of garlic is multifaceted and includes activation of genes related to immunity, apoptosis, and xenobiotic metabolism.