Integration of bioassay and non-target metabolite analysis of tomato reveals that ß-carotene and lycopene activate the adiponectin signaling pathway, including AMPK phosphorylation.

Adiponectin, an adipokine, regulates glucose metabolism and insulin sensitivity through the adiponectin receptor (AdipoR). In this study, we searched for metabolites that activate the adiponectin signaling pathway from tomato (Solanum lycopersicu). Metabolites of mature tomato were separated into 55 fractions by liquid chromatography, and then each fraction was examined using the phosphorylation assay of AMP-protein kinase (AMPK) in C2C12 myotubes and in AdipoR-knockdown cells by small interfering RNA (siRNA). Several fractions showed AMPK phosphorylation in C2C12 myotubes and siRNA-mediated abrogation of the effect. Non-targeted metabolite analysis revealed the presence of 721 diverse metabolites in tomato. By integrating the activity of fractions on AMPK phosphorylation and the 721 metabolites based on their retention times of liquid chromatography, we performed a comprehensive screen for metabolites that possess adiponectin-like activity. As the screening suggested that the active fractions contained four carotenoids, we further analyzed ß-carotene and lycopene, the major carotenoids of food. They induced AMPK phosphorylation via the AdipoR, Ca2+/calmodulin-dependent protein kinase kinase and Ca2+ influx, in addition to activating glucose uptake via AdipoR in C2C12 myotubes. All these events were characteristic adiponectin actions. These results indicated that the food-derived carotenoids, ß-carotene and lycopene, activate the adiponectin signaling pathway, including AMPK phosphorylation.

Effects of Heat-Killed Levilactobacillus brevis KB290 in Combination with ß-Carotene on Influenza Virus Infection in Healthy Adults: A Randomized Controlled Trial.

Influenza, a seasonal acute respiratory disease caused primarily by the influenza virus A or B, manifests with severe symptoms leading to considerable morbidity and mortality and is a major concern worldwide. Therefore, effective preventive measures against it are required. The aim of this trial was to evaluate the preventive effects of heat-killed Levilactobacillus brevis KB290 (KB290) in combination with ß-carotene (ßC) on influenza virus infections in healthy Japanese subjects aged between 20 and 59 y throughout the winter season. We performed a randomized, double-blind, placebo-controlled, parallel-group trial from 16 December 2019 to 8 March 2020, comparing KB290 + ßC beverage with placebo beverage. The primary endpoint was the incidence of influenza based on a doctor's certificate. The incidence of influenza was not significantly different between the two groups. However, the subgroup analysis showed a significant difference between the two groups (influenza incidence: the KB290 + ßC group 1.9%, and the placebo group 3.9%) in the subgroup of subjects aged ˂40 y, but not in the subgroup of subjects aged ≥40 y. The results of this trial suggest that the combination of KB290 and ßC might be a possible candidate supplement for protection against the seasonal influenza virus infection in humans aged <40 y, although further clinical studies are needed to confirm the concrete preventive effect of this combination on influenza.

TOMATOMET: A metabolome database consists of 7118 accurate mass values detected in mature fruits of 25 tomato cultivars.

The total number of low-molecular-weight compounds in the plant kingdom, most of which are secondary metabolites, is hypothesized to be over one million, although only a limited number of plant compounds have been characterized. Untargeted analysis, especially using mass spectrometry (MS), has been useful for understanding the plant metabolome; however, due to the limited availability of authentic compounds for MS-based identification, the identities of most of the ion peaks detected by MS remain unknown. Accurate mass values of peaks obtained by high accuracy mass measurement and, if available, MS/MS fragmentation patterns provide abundant annotation for each peak. Here, we carried out an untargeted analysis of compounds in the mature fruit of 25 tomato cultivars using liquid chromatography-Orbitrap MS for accurate mass measurement, followed by manual curation to construct the metabolome database TOMATOMET (http://metabolites.in/tomato-fruits/). The database contains 7,118 peaks with accurate mass values, in which 1,577 ion peaks are annotated as members of a chemical group. Remarkably, 71% of the mass values are not found in the accurate masses detected previously in Arabidopsis thaliana, Medicago truncatula or Jatropha curcas, indicating significant chemical diversity among plant species that remains to be solved. Interestingly, substantial chemical diversity exists also among tomato cultivars, indicating that chemical profiling from distinct cultivars contributes towards understanding the metabolome, even in a single organ of a species, and can prioritize some desirable metabolic targets for further applications such as breeding.

Association between Biomarkers of Cardiovascular Diseases and the Blood Concentration of Carotenoids among the General Population without Apparent Illness.

Several studies have demonstrated that carotenoid-rich vegetables are useful against cardiovascular diseases (CVDs). However, it is still unclear when a healthy population should start eating these vegetables to prevent CVDs. In this study, we evaluated the role of carotenoids in CVD markers in healthy subjects using age-stratified analysis. We selected 1350 subjects with no history of apparent illness who were undergoing health examinations. We then evaluated the relationship between the serum concentrations of six major carotenoids as well as their total, and nine CVD markers (i.e., body mass index (BMI), pulse wave velocity (PWV), systolic blood pressure (SBP), diastolic blood pressure (DBP), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), blood insulin, fasting blood glucose (FBG), triglycerides (TGs), and high-density lipoprotein (HDL) cholesterol) using multiple regression analysis. It was found that the total carotenoid level was significantly associated with seven markers other than BMI and FBG in males and with eight markers other than DBP in females. Many of these relationships were independent of lifestyle habits. Many significant relationships were found in young males (aged 20-39) and middle-aged females (aged 40-59). These findings can be used as lifestyle guidance for disease prevention although the causal relationships should be confirmed.

Apo-12'-lycopenal, a Lycopene Metabolite, Promotes Adipocyte Differentiation via Peroxisome Proliferator-Activated Receptor γ Activation.

Apo-lycopenals, lycopene metabolites produced by an initial cleavage by ß,ß-carotene-9',10'-oxygenase, exhibit diverse biologically active effects. In this study, we investigated the effect of apo-lycopenals on the activation of nuclear receptors involved in glucose and lipid metabolism. Only apo-12'-lycopenal exhibited selective and dose-dependent transactivation activity for peroxisome proliferator-activated receptor γ (PPARγ), whereas neither apo-6'- nor apo-8'-lycopenals displayed this activity ((7.83 ± 0.66)-, (1.32 ± 0.10)-, and (1.31 ± 0.37)-fold higher activity relative to control, respectively). Additionally, apo-12'-lycopenal promoted adipocyte differentiation of 3T3-L1 cells and subsequently increased the mRNA levels of PPARγ (a (2.36 ± 0.07)-fold increase relative to control; p < 0.01) and its target genes, as well as enhanced adiponectin secretion (a (3.25 ± 0.27)-fold increase relative to control; p < 0.01) and insulin-stimulated glucose uptake (1486 ± 85 pmol/well; p < 0.001) in 3T3-L1 cells. Our results indicated that apo-12'-lycopenal promoted adipocyte differentiation by direct binding and activation of PPARγ.

Wide-range screening of anti-inflammatory compounds in tomato using LC-MS and elucidating the mechanism of their functions.

Obesity-induced chronic inflammation is a key factor in type 2 diabetes. A vicious cycle involving pro-inflammatory mediators between adipocytes and macrophages is a common cause of chronic inflammation in the adipose tissue. Tomato is one of the most popular vegetables and is associated with a reduced risk of diabetes. However, the molecular mechanism underlying the effect of tomato on diabetes is unclear. In this study, we focused on anti-inflammatory compounds in tomato. We found that the extract of tomato reduced plasma glucose and inflammatory markers in mice. We screened anti-inflammatory fractions in tomato using lipopolysaccharide-stimulated RAW264.7 macrophages, and active compounds were estimated by liquid chromatography-mass spectrometry over a wide range. Surprisingly, a large number of compounds including oxylipin and coumarin derivatives were estimated as anti-inflammatory compounds. Especially, 9-oxo-octadecadienoic acid and daphnetin suppressed pro-inflammatory cytokines in RAW264.7 macrophages inhibiting mitogen-activated protein kinase phosphorylation and inhibitor of kappa B α protein degradation. These findings suggest that tomato containing diverse anti-inflammatory compounds ameliorates chronic inflammation in obese adipose tissue.

Amelioration of Citrobacter rodentium proliferation in early stage of infection in mice by pretreatment with Lactobacillus brevis KB290 and verification using in vivo bioluminescence imaging.

Bioluminescent imaging (BLI) has become a useful tool for monitoring bacterial infections in real time. Citrobacter rodentium and its BLI are widely used as a murine model of enteropathogenic and enterohaemorrhagic Escherichia coli infection. In this study, we evaluated the protective effects of the probiotic Lactobacillus brevis KB290 against C. rodentium infection by the BLI approach. First, we examined several solutions for making the suspension of bioluminescent C. rodentium for an oral inoculation to establish a stable intestinal infection. Three percent NaHCO3 solution was found to be the best. Subsequently, mice were orally administered KB290 once daily for 7 days before inoculation with bioluminescent C. rodentium and for 8 days after infection. The bioluminescence intensity of mice fed with KB290 was significantly lower than that of unfed mice on days 1-3 after infection. The mRNA levels of tumour necrosis factor-α and interferon-γ in the distal colon from KB290-fed mice were shown to be significantly higher than those from unfed mice on day 3 after infection. The results suggested that KB290 intake partially inhibited the proliferation of C. rodentium, especially in the early stages of infection, viathe moderate enhancement of tumour necrosis factor-α and interferon-γ production in the colon.