(P05-042-20) Effects of Nut Consumption on Colon Cell Proliferation, Apoptosis, and Inflammation Gene Expression
Objectives: A disruption to the colon cell kinetic balance can increase one’s risk for colorectal cancer (CRC). Studies using single nut consumption has been found to decrease CRC risk. This study aimed to determine if mixed nut consumption would be as effective as or even better than single nut consumption at preventing CRC through modulation of colon cell proliferation and apoptosis cell numbers in a healthy rat model. It was hypothesized that rats consuming a mixed nut diet would exhibit fewer proliferative cells and greater apoptotic cells compared to a single nut diet and a control.
Methods: Thirty 21-day-old Sprague Dawley male rats were assigned to one of three isocaloric diets: control diet (no nuts), pistachio diet, or mixed nut diet for eight weeks. The mixed nut diet contained almonds, Brazil nuts, cashews, macadamia nuts, peanuts, pecans, pistachios, and walnuts. Proliferative cells were marked using Ki-67 quantitative immunostaining and apoptotic cells with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Colonic gene expression of prostaglandin endoperoxide synthase 2 (Ptgs2), nuclear factor kappa-B p65 subunit (Rela), Cyclin D1 (Ccnd1), peroxisome proliferator-activated receptor gamma (Pparγ), superoxide dismutase (SOD), and catalase (Cat) were determined by real-time quantitative polymerase chain reaction analysis.
Results: No significant differences were found in proliferation and apoptosis cell numbers between all three groups. Significantly lower levels of the inflammatory marker, Ptgs2, were only observed between the pistachio group and the control (p = 0.045). While both the pistachio and mixed nut groups had significantly lower levels of Rela compared to the control (p = 0.041). No significant differences were found among diets for Cyclind1, Pparγ, Sod, and Cat.
Conclusions: The results of this study show that nut groups were able to downregulate inflammation gene expression without alteration to colon cell proliferation and apoptosis. A longer study duration is needed to investigate if the lower gene expression involved in inflammation from nut consumption may change cell kinetics and further reduce colon cancer.
Funding Sources: American Heart Association (16GRNT31360007)
San Diego State University San Diego, California
Mee Young Hong
Professor San Diego State University San Diego, California