Craig S. Charron

Bioavailability of anthocyanins from purple carrot juice: effects of acylation and plant matrix.

Absorption of cyanidin-based anthocyanins is not fully understood with respect to dose or anthocyanin structure. In feeding studies using whole foods, nonacylated anthocyanins are more bioavailable than their acylated counterparts, but the extent to which plant matrix determines relative bioavailability of anthocyanins is unknown. Using juice of purple carrots to circumvent matrix effects, a feeding trial was conducted to determine relative bioavailability of acylated and nonacylated anthocyanins and to assess dose-response effects. Appearance of anthocyanins in plasma was measured in 10 healthy adults for 8 h following consumption of purple carrot juice. Each subject consumed 50, 150, and 250 mL of juice containing 76 micromol (65 mg), 228 micromol (194 mg), and 380 micromol (323 mg) of total anthocyanins, respectively. Acylated anthocyanins comprised 76% of total anthocyanins in the juice, yet their bioavailability was found to be significantly less than that of nonacylated anthocyanins. Peak plasma concentrations of nonacylated anthocyanins were 4-fold higher than that for acylated anthocyanins. Absorption efficiency declined across the doses administered. Because the treatments were consumed as juice, it could be discerned that the difference in bioavailability of acylated versus nonacylated anthocyanins was not primarily caused by interactions with the plant matrix.

A Single Meal Containing Raw, Crushed Garlic Influences Expression of Immunity- and Cancer-Related Genes in Whole Blood of Humans

BACKGROUND Preclinical and epidemiologic studies suggest that garlic intake is inversely associated with the progression of cancer and cardiovascular disease. OBJECTIVE We designed a study to probe the mechanisms of garlic action in humans. METHODS We conducted a randomized crossover feeding trial in which 17 volunteers consumed a garlic-containing meal (100 g white bread, 15 g butter, and 5 g raw, crushed garlic) or a garlic-free control meal (100 g white bread and 15 g butter) after 10 d of consuming 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 quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on selected genes. To augment human study findings, 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. RESULTS The following 7 genes were found to be upregulated by garlic intake: aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor nuclear translocator (ARNT), hypoxia-inducible factor 1α (HIF1A), proto-oncogene c-Jun (JUN), nuclear factor of activated T cells (NFAT) activating protein with immunoreceptor tyrosine-based activation motif 1 (NFAM1), oncostatin M (OSM), and V-rel avian reticuloendotheliosis viral oncogene homolog (REL). Fold-increases in mRNA transcripts ranged from 1.6 (HIF1A) to 3.0 (NFAM1) (P < 0.05). The mRNA levels 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 the control at 3, 6, and 24 h (24 h: 19.5 ± 1.4 and 74.8 ± 1.4 pg/mL for control and garlic, respectively). OSM is a pleiotropic cytokine that inhibits several tumor cell lines in culture. CONCLUSION These data indicate that the bioactivity of garlic is multifaceted and includes activation of genes related to immunity, apoptosis, and xenobiotic metabolism in humans and Mono Mac 6 cells. This trial is registered at clinicaltrials.gov as NCT01293591.

Broccoli consumption affects the human gastrointestinal microbiota

The human gastrointestinal microbiota is increasingly linked to health outcomes; however, our understanding of how specific foods alter the microbiota is limited. Cruciferous vegetables such as broccoli are a good source of dietary fiber and phytonutrients, including glucosinolates, which can be metabolized by gastrointestinal microbes. This study aimed to determine the impact of broccoli consumption on the gastrointestinal microbiota of healthy adults. A controlled feeding, randomized, crossover study consisting of two 18-day treatment periods separated by a 24-day washout was conducted in healthy adults (n=18). Participants were fed at weight maintenance with the intervention period diet including 200 g of cooked broccoli and 20 g of raw daikon radish per day. Fecal samples were collected at baseline and at the end of each treatment period for microbial analysis. Beta diversity analysis indicated that bacterial communities were impacted by treatment (P=.03). Broccoli consumption decreased the relative abundance of Firmicutes by 9% compared to control (P=.05), increased the relative abundance of Bacteroidetes by 10% compared to control (P=.03) and increased Bacteroides by 8% relative to control (P=.02). Furthermore, the effects were strongest among participants with body mass index <26 kg/m2, and within this group, there were associations between bacterial relative abundance and glucosinolate metabolites. Functional prediction revealed that broccoli consumption increased the pathways involved in the functions of the endocrine system (P=.05), transport and catabolism (P=.04), and energy metabolism (P=.01). These results reveal that broccoli consumption affects the composition and function of the human gastrointestinal microbiota.

Screening of Nine Echinacea Supplements for Antitumor Activity Using the Potato Disc Bioassay

ABSTRACT To study the efficacy of commercially available Echinacea supplements, solvent fractions from nine locally purchased supplements containing Echinacea were tested in a potato disc assay for their ability to suppress formation of crown-gall tumors, a process that resembles tumor formation in animal tissues. Acetone and ethanol fractions from two supplements inhibited tumor formation and water and ethanol fractions from a third supplement suppressed tumor formation. Comparison of the bio-assay results with the supplement ingredients, as listed on the supplement label, did not reveal any correlation between quantity and suppressive activity of the listed ingredients. These results are consistent with prior investigations that noted product labels were often inaccurate and that post-harvest handling practices can be deleterious to bioactive compounds contained in Echinacea.