12 research outputs found
Quercetin Inhibits Advanced Glycation End Product Formation by Trapping Methylglyoxal and Glyoxal
Methylglyoxal (MGO) and glyoxal (GO)
not only are endogenous metabolites
but also exist in exogenous resources, such as foods, beverages, urban
atmosphere, and cigarette smoke. They have been identified as reactive
dicarbonyl precursors of advanced glycation end products (AGEs), which
have been associated with diabetes-related long-term complications.
In this study, quercetin, a natural flavonol found in fruits, vegetables,
leaves, and grains, could effectively inhibit the formation of AGEs
in a dose-dependent manner via trapping reactive dicarbonyl compounds.
More than 50.5% of GO and 80.1% of MGO were trapped at the same time
by quercetin within 1 h under physiological conditions. Quercetin
and MGO (or GO) were combined at different ratios, and the products
generated from this reaction were analyzed with LC-MS. Both mono-MGO
and di-MGO adducts of quercetin were detected in this assay using
LC-MS, but only tiny amounts of mono-GO adducts of quercetin were
found. Additionally, di-MGO adducts were observed as the dominant
product with prolonged incubation time. In the bovine serum albumin
(BSA)–MGO/GO system, quercetin traps MGO and GO directly and
then significantly inhibits the formation of AGEs
Influence of Quercetin and Its Methylglyoxal Adducts on the Formation of α‑Dicarbonyl Compounds in a Lysine/Glucose Model System
Increasing evidence has identified
α-dicarbonyl compounds,
the reactive intermediates generated during Maillard reaction, as
the potential factors to cause protein glycation and the development
of chronic diseases. Therefore, there is an urgent need to decrease
the levels of reactive dicarbonyl compounds in foods. In this study,
we investigated the inhibitory effect of quercetin, a major dietary
flavonoid, and its major mono- and di-MGO adducts on the formation
of dicarbonyl compounds, such as methylglyoxal (MGO) and glyoxal (GO),
in a lysine/glucose aqueous system, a model system to reflect the
Maillard reaction in food process. Our result indicated that quercetin
could efficiently inhibit the formation of MGO and GO in a time-dependent
manner. Further mechanistic study was conducted by monitoring the
formation of quercetin oxidation and conjugation products using LC-MS/MS.
Quercetin MGO adducts, quercetin quinones, and the quinones of quercetin
MGO adducts were detected in the system, indicating quercetin plays
a dual role in inhibiting the formation of MGO and GO by scavenging
free radicals generated in the system and trapping of MGO and GO to
form MGO adducts. In addition, we prepared the mono- and di-MGO quercetin
adducts and investigated their antioxidant activity and trapping capacity
of MGO and GO. Our results indicated that both mono- and di-MGO quercetin
adducts could scavenge the DPPH radical in a dose-dependent manner
with >40% DPPH scavenged by the MGO adducts at 10 μM, and
the
di-MGO quercetin adduct could further trap MGO to generate tri-MGO
adducts. Therefore, we demonstrate for the first time that quercetin
MGO adducts retain the antioxidant activity and trapping capacity
of reactive dicarbonyl species
Elimination of Acrolein by Disodium 5′-Guanylate or Disodium 5′-Inosinate at High Temperature and Its Application in Roasted Pork Patty
Acrolein (ACR) is a highly active, simple unsaturated
aldehyde
found in various high-temperature processed foods. Its long-term accumulation
in the human body increases the risk of chronic diseases. Animal and
plant foodstuffs are rich in disodium 5′-guanylate (GMP) and
disodium 5′-inosinate (IMP), which are authorized flavor enhancers.
Herein, we used liquid chromatography with tandem mass spectrometry
to explore the reaction-active kinetics and pathway of the interaction
between GMP/IMP and ACR and validated it in roasted pork patties.
Our results suggested that GMP and IMP could efficiently eliminate
ACR by forming ACR adducts (GMP–ACR, IMP–ACR). In addition,
IMP exhibited a higher reaction rate, whereas GMP had a good trapping
capacity at a later stage. As carriers of GMP and IMP, dried mushrooms
and shrimp exhibited an effective ACR-trapping ability in the ACR
model and roasted pork patty individually and in combination. Adding
10% of dried mushroom or shrimp alone or 5% of dried mushroom and
shrimp in combination eliminated up to 53.9%, 55.8%, and 55.2% ACR
in a roasted pork patty, respectively. This study proposed a novel
strategy to eliminate the generation of ACR in roasted pork patties
by adding foodstuffs rich in GMP and IMP
Scavenging Glyoxal and Methylglyoxal by Synephrine Alone or in Combination with Neohesperidin at High Temperatures
α-Dicarbonyl compounds, such as glyoxal (GO) and
methylglyoxal
(MGO), are a series of chemical hazards that exist in vivo and in
vitro, posing a threat to human health. We aimed to explore the scavenging
effects on GO/MGO by synephrine (SYN) alone or in combination with
neohesperidin (NEO). First, through LC–MS/MS, we confirmed
that both SYN and NEO could effectively remove GO and form GO adducts,
while NEO could also clear MGO by forming MGO adducts, and its ability
to clear MGO was stronger than that of GO. Second, a synergistic inhibitory
effect on GO was found when SYN and NEO were used in combination by
using the Chou–Talalay method; on the other hand, SYN could
promote NEO to clear more MGO, although SYN could not capture MGO.
Third, after synthesizing four GO/MGO-adducts (SYN-GO-1, SYN-GO-3,
NEO-GO-7, and NEO-MGO-2) and identifying their structure through NMR,
strict correlations between the GO/MGO-adducts and the GO/MGO-clearance
rate were found when using SYN and NEO alone or in combination. Furthermore,
it was inferred that the synergistic effect between SYN and NEO stems
from their mutual promotion in capturing more GO by the quantitative
analysis of the adducts in the combined model. Finally, a study was
conducted on flowers of Citrus aurantium L. var. amara Engl. (FCAVA, an edible tea) rich in SYN and NEO,
which could serve as an effective GO and MGO scavenger in the presence
of both GO and MGO. Therefore, our study provided well-defined evidence
that SYN and NEO, alone or in combination, could efficiently scavenge
GO/MGO at high temperatures, whether in the pure form or located in
FCAVA
Over-expression of <i>bmp2b</i> specifically localized in the CHT area at 79 hpf upon ginger or 10-G exposure in normal and in anemic zebrafish embryos.
<p>Whole-mount in situ hybridization of <i>bmp2b.</i> (A–C, left) Normal non-anemic control embryos or embryos treated with ginger/10-G. (D–F, right) Anemic control embryos or anemic embryos treated with ginger/10-G. Anemic groups were treated with 0.5 µM PHZ from 33 to 48 hpf. Embryos express <i>bmp2b</i> in the CHT region (arrows) following exposure to ginger (B, E) or 10-G (C, F). (G) A table shows the percentage of embryos with <i>bmp2b</i> expression in the CHT area at 79 hpf. Scale bars = 420 µm.</p
Ginger/10-G treatment after gastrulation promotes <i>bmp2b/7a</i> in the developing caudal hematopoietic tissue.
<p>(A–B) Zebrafish embryos were treated with ginger (5 µg/ml) or 10-G (2 µg/ml) from 10 to 48 hpf, followed by whole-mount in situ hybridization of <i>bmp2b</i> (A) and <i>bmp7a</i> (B). Both <i>bmp2b</i> and <i>bmp7a</i> were up-regulated locally in the CHT (and underlying fin) upon ginger or 10-G exposure (whereas they are not expressed in the CHT of control embryos at 48 hpf). Scale bars = 700 µm.</p
Over-expression of <i>bmp7a</i> specifically localized in the CHT region at 79 hpf upon ginger or 10-G exposure in normal and in anemic zebrafish embryos.
<p>Whole-mount in situ hybridization of <i>bmp7a</i>. (A–C, left) Normal non-anemic control embryos or embryos treated with ginger/10-G. (D–F, right) Anemic control embryos or anemic embryos treated with ginger/10-G. Anemic group were treated with 0.5 µM PHZ from 33 to 48 hpf. Embryos express <i>bmp7a</i> in the CHT area (arrows) following exposure to ginger (B, E) or 10-G (C, F). (G) A table shows the percentage of embryos with <i>bmp7a</i> expression in the CHT region at 79 hpf. Scale bars = 420 µm.</p
Ginger/10-G treatment during gastrulation promotes <i>bmp2b/7a</i> and Bmp target gene expression in zebrafish embryos.
<p>(A) Treatment of late gastrulae with ginger at 15 or 20 µg/ml induces the <i>mercedes</i> mutant-like phenotype (partial duplication of the tail fin) at 1 dpf in 8% or 10% of the treated embryos, respectively. Thus, the zebrafish embryos exposed to ginger extract mimic the phenotype of the <i>ogon</i> mutant, which has a mutation in <i>sizzled</i>, a <i>bmp</i> suppressor gene, at 1 dpf. (B) <i>bmp7a</i> expression was strongly increased and extended to the entire blastoderm at 60% epiboly, following short-term exposure to ginger (5 µg/ml) or 10-G (1 µg/ml) from sphere (4 hpf) to 60% epiboly (7 hpf) stages. (C) Up-regulation and extension of the expression domain were observed for <i>bmp2b</i> at 60% epiboly. (D–E) Accordingly, BMP target genes were up-regulated after ginger/10G treatment from the sphere stage (4 hpf) to 7 hpf, as illustrated by enhanced <i>eve1</i> extended towards the dorsal side (arrow heads), a ventral mesoderm marker (D), and <i>gata2,</i> a non-neural ectoderm marker (E), in zebrafish embryos at 60% epiboly. Pictures on left panels show gastrulae, dorsal side to the right (B–E) and statistics tables (right panels) are representative of three independent experiments. N = number of embryos per group. Scale bars = 250 µm.</p
Ginger extract and its purified phenolic compounds promote <i>Tg(gata1:dsRed)</i> fluorescence and <i>gata1</i> mRNA expression.
<p>(A) Bright field (top left) and <i>Tg(gata1:dsRed)</i> fluorescence of zebrafish embryos at about 22 hpf, before the onset of circulation (anterior to the left). Exposure to ginger extract or its compounds 8-gingerol (8-G), 10-gingerol (10-G), 8-shogaol (8-S) and 10-shogaol (10-S) promoted <i>Tg(gata1:dsRed)</i> fluorescent erythroid cell development in the ICM and PBI (arrows), as compared to control embryos. N = 35 embryos per group. In this panel, we show an embryo treated with a lower concentration of 6-S (2 µg/ml) as this compound was toxic at higher doses. Scale bar = 400 µm. (B) Whole-mount in situ hybridization of ginger or 10-G treated embryos (8 hpf to 21 hpf exposure) revealed increased expression of <i>gata1</i> transcript at 22 hpf. N = 50 embryos per group. Scale bar = 350 µm. (C) At 48 hpf, control embryos at the top; ginger or 10-G treated embryos at the bottom. Scale bar = 500 µm. Fluorescent erythrocytes circulating in the axial vasculature (arrows) and in the pericardial space (arrow heads).</p
Ginger/10-G treatment increases hematopoietic progenitor markers expression.
<p>Zebrafish embryos were treated with ginger or 10-G from 9 to 21 hpf. (A) <i>Tg(gata1:dsRed)</i> for erythrocyte and <i>Tg(flk1:GFP)</i> for blood vessels, double-fluorescent overlay pictures of embryos at 22 hpf after exposure to ginger or 10-G. Hypertrophy of the PBI vascular plexus in <i>Tg(flk1:GFP)</i> after ginger or 10-G treatment, with <i>Tg(gata1:dsRed)</i> red fluorescent erythrocytes accumulated inside the honeycomb-like vasculature (arrows). Scale bars = 500 µm. Whole-mount in situ hybridization of <i>c-myb</i> (B) and <i>scl</i> (C) in zebrafish embryos at 22 hpf. Both hematopoietic progenitor markers were up-regulated in primitive hematopoietic tissues (ICM+PBI) upon ginger (arrow head) or 10-G (arrow) exposure. Scale bar = 350 µm.</p