Location: Diet, Genomics and Immunology Laboratory
2020 Annual Report
Objectives
Objective 1: Determine the accumulation and variability of important bioactive compounds in commonly consumed food crops as affected by factors such as stage of maturity (leafy greens harvested at various stages of maturity) and variety/processing (coffee products derived from different sources). [NP107, C1, PS1A]
Objective 2: Determine bioavailability and cellular uptake of potential compounds in coffee products; investigate their effects on subclinical inflammation and its associated events related to chronic metabolic diseases; elucidate mechanisms of action on subclinical inflammation and related events. [NP107, C3, PS3B]
Objective 3: Determine effects of brassica vegetables harvested at different stages of maturity (e.g., sprout, microgreen, baby green, mature plant) on high fat diet-induced inflammation, and adipose uncoupling protein 1 (UCP1) as mechanisms for their attenuation of high fat diet-induced weight gain. Elucidate the role of the microbiome in mediating changes in inflammation and liver lipid metabolism. [NP107, C3, PS3B]
Approach
Objective 1: Amounts of bioactive compounds in selected model plant products (e.g., coffee beans grown in different regions/conditions, coffee products, brassica vegetables harvested at different stages of maturity) will be determined using established HPLC, MS/MS and NMR methods.
Objective 2: Both in-vivo and in-vitro models will be used for this objective. (1) We will determine bioavailability and cellular uptake of coffee compounds using cell culture (e.g., Caco-2, HepG2, monocytic THP-1) models. HPLC, metabolomic and lipidomic analytical technologies will be used to measure the compounds and associated metabolites. (2) We will determine potential effects of coffee/coffee chemicals (javamide-I/-II) on subclinical inflammation markers using a rodent model. Obesity will be induced in animals (e.g., rats) fed a high-fat diet, and the potential effects of coffee and coffee compounds (e.g., javamide-I/-II) on obesity-associated subclinical inflammation and biological changes will be determined to elucidate the effects. (3) We will determine the cellular/molecular mechanisms responsible for the biological effects using cell culture models. Cell will be treated with the compounds and effects of compounds on cellular pathways related to signal transduction pathways, inflammatory cytokines, adhesion molecular, transcriptional factors will be assessed at protein and message levels using western blots, ELISA and RT-PCR.
Objective 3: We will determine effects of brassica vegetables harvested at different stages of maturity (e.g., sprout, microgreen, baby green, mature plant) on high fat diet-induced rodent model. Inflammatory marker and adipose uncoupling protein 1 (UCP1) will be assessed using ELISA at protein level and RT-PCR at message level as mechanisms for their attenuation of high fat diet-induced weight gain. Biochemical and marker genes analysis will be performed in liver and adipose tissues to assess the effects on lipid and energy metabolism. Metagenomic analysis using next generation sequencing technology will be performed to elucidate the role of the microbiome in mediating changes in inflammation and liver lipid metabolism.
Progress Report
This report is for a NP107 approved project entitled “Elucidating Phytonutrient Bioavailability, Health Promoting Effects and Mechanisms of Existing/Emerging Foods and Beverages.” We focus on two foods, coffee and kale, at different growth/maturation states. The following describes the current progress of the project:
The reported health-promoting phytochemicals, glucosinolates and polyphenols, in kale and kale microgreens were characterized by UHPLC-HRMS analysis. The total concentration of polyphenols in microgreen kale was slightly higher (22.46±1.24 mg/g) than in mature kale (20.0±5.3 mg/g). However, the polyphenol compound profiles were markedly different; a wider variety of polyphenol compounds were found in the mature kale than in the kale microgreens. The caffeoyl glycoside, feruloyl glucose, sinapoyl glycoside and quercetin-3-disinapoyl- triglucoside-7-glucoside were only detected in the kale microgreens. Moreover, trisinapoyl-diglucoside content in the kale microgreens (327.58 µg/ml) was ~30X greater than its mature counterpart (12.58 µg/ml). For glucosinolates, kale microgreens, and mature kale have very similar compound profiles. However, kale microgreens (29.3±2.66 µmol/g) had ~5X more total glucosinolates than the mature kale (4.14±0.64 µmol/g). Specifically, glucosativin is only detected in the kale microgreens and the concentration of sinigrin in the kale microgreens (16.49 µmol/g) was ~30X greater than that of the mature kale (0.54 µmol/g). Hence, kale microgreens and mature kale appeared to differ in polyphenol and glucosinolate profiles and concentrations.
We also conducted studies to examine the potential effects of coffee compounds and their molecular mechanisms to address the gaps in the literature. We investigated the potential effects of javamide-II found in coffee on the increase in inflammatory cytokines associated with several human diseases (e.g., diabetes, liver disease, acute microbial/viral infection). We found that javamide-II could inhibit IL-6 inflammatory cytokine significantly at =0.5 µM in macrophage-like cells, compared to other inflammatory cytokines (e.g., TNF-alpha and IL-1beta). The study suggests that javamide-II may be used as a selective IL-6 inhibitor. We then investigated the effects of javamide-II on signal transduction pathways. MAP kinases (ERK, p38, JNK) are major signal transduction pathways critical for the production of inflammatory cytokines (e.g., TNF-alpha, IL-1beta, IL-6). Our studies showed that javamide-II could inhibit p38 (not ERK or JNK) in the macrophage-like THP-1 cells. The study suggests that javamide-II may inhibit IL-6 via suppressing p38 in macrophage-like cells. We also investigated the effects of other novel coffee compounds (kahweol and cafestol) on lymphocyte activation which is critically associated with the initiation/progression of several inflammatory diseases (liver disease, autoimmune diseases). Our study showed that kahweol and cafestol could inhibit the activation of lymphocytic Jurkat cells via suppressing IL-2 and TNF-alpha production. These studies suggest that coffee may contain several novel anti-inflammatory compounds. Finally, we initiated an animal study to determine the effects of javamide-II on high fat diet induced-subclinical inflammation.
Accomplishments
1. Elucidate regulation of chemokine receptors and their role in metastasis of prostate cancer cells. Inflammation is a major risk factor in the development of prostate cancer, but the molecular mechanisms remain unclear. ARS scientists, in Beltsville, Maryland, in collaboration with University of Maryland collaborators, utilized a cell culture model to elucidate how inflammation may act to promote prostate cancer development. Androgen and inflammatory stimuli were identified as major factors that regulate the CXC chemokine receptors and lead to the promotion of prostate cancer cell migration. These effects thus enhance the metastatic potential of prostate cancer cells. This study provided information on molecular mechanisms underlying the enhanced metastatic potential of malignant prostate cancer cells.
2. Identify cruciferous vegetable-derived compound indole-3-carbinol to be protective against food-borne pathogen-induced intestinal inflammation. Health promoting effects of cruciferous vegetable consumption is documented in population studies but the precise effect, the specific bioactive compound involved and the mechanism remain unclear. ARS scientists in Beltsville, Maryland, in collaboration with the University of Maryland and NCI collaborators, utilized a rodent food-borne pathogen (E. coli-like bacteria citrobacter rodentium) induced intestinal inflammation model to test the efficacies of the cruciferous vegetable-derived compound, indole-3-carbinol. Indole-3-carbinol was found to be cytotoxic to the bacteria and prevented the attachment of the bacteria to colonic cells and afforded protection against infection and intestinal inflammation. This study identified a specific bioactive compound, indole 3-cabionol, derived from cruciferous vegetable that has health-promoting effects and provides possible molecular mechanistic information on how food-derived bioactive compounds may protect against intestinal inflammation induced by food-borne pathogens.
Review Publications
Yu, L., Pham, Q., Yu, L., Wang, T.T. 2019. Modulation of CXC-motif chemokine receptor 7, but not 4 expression, is related to migration of the human prostate cancer cell LNCaP: regulation by androgen and inflammatory stimuli. Inflammation Research. 69, 167-178. https://doi.org/10.1007/s00011-019-01305-0.
Wu, Y., He, Q., Yu, L., Pham, Q., Cheung, L., Kim, Y.S., Wang, T.T., Smith, A.D. 2020. Indole-3-carbinol inhibits Citrobacter rodentium infection through multiple pathways including reduction of bacterial adhesion and enhancement of cytotoxic T cell activity. Nutrients. 12(4):917. https://doi.org/doi: 10.3390/nu12040917.
Lu, M., Li, X., Zhou, S., Wang, T.T., Zhou, S., Yang, K., Li, Y., Tian, J., Wang, J. 2020. Dietary fiber isolated from sweet potato residues promotes healthy gut microbiome profile. Food and Function. 11, 689-699. https://doi.org/10.1039/c9fo01009b.
Liu, F., Wang, T.T., Tang, Q., Xue, C., Li, R.W., Wu, V.C. 2019. Malvidin 3-glucoside modulated gut microbial dysbiosis and global metabolome disrupted in a murine colitis model induced by dextran sulfate sodium. Molecular Nutrition and Food Research. 1900455:1-14. https://doi.org/10.1002/mnfr.201900455.
Aggarwal, M., Saxena, R., Asif, N., Sinclair, E., Tan, J., Cruz, I., Berry, D., Kallakury, B., Pham, Q., Wang, T.T., Fung-Lung, C. 2019. The p53 mutation-site in prostate cancer determines its sensitivity to phenethyl isothiocyanate induced growth inhibition. Journal of Experimental and Clinical Cancer Research. 38(1):307. https://doi.org/10.1186/s13046-019-1267-z.
Park, J.B., Peters, R.C., Pham, Q., Wang, T.T. 2020. Javamide-II inhibits IL-6 without significant impact on TNF-alpha and IL-1beta in macrophage-like cells. BioMedical Journal. 8(6);138. https://doi.org/10.3390/biomedicines8060138.
Liu, J., Li, Y., Yang, P., Wan, J., Zhang, Y., Gao, B., Wang, Z., Wang, T.T., Yu, L. 2017. Gypenosides reduced the risk of overweight and insulin resistance in C57BL/6J mice through modulating adipose thermagenesis and gut microbiota. Journal of Food Science and Nutrition. 65(42)9237-9246. https://doi.org/doi: 10.1021/acs.jafc.7b03382.
Choe, U., Li, Y., Gao, B., Yu, L., Wang, T.T., Sun, J., Chen, P., Yu, L. 2020. Chemical composition of cold-pressed blackberry seed flour extract and its potential health-beneficial properties. Food Science and Nutrition. 8(2):1215-1225. https://doi.org/10.1002/fsn3.1410.
