Genoprotective Effect of Some Flavonoids against Genotoxic Damage Induced by X-rays In Vivo: Relationship between Structure and Activity

Flavonoids constitute a group of polyphenolic compounds characterized by a common gamma-benzo- pyrone structure considered in numerous biological systems to possess antioxidant capacity. Among the different applications of flavonoids, its genoprotective capacity against damage induced by ionizing radiation stands out, which has been related to antioxidant activity and its chemical structure. In this study, we determined the frequency of appearance of micronucleus in vivo by means of the micronucleus assay. This was conducted in mice treated with different flavonoids before and after exposure to 470 mGy X-rays; thereafter, their bone marrow polychromatophilic erythrocytes were evaluated to establish the structural factors enhancing the observed genoprotective effect. Our results in vivo show that the presence of a monomeric flavan-3-ol type structure, with absence of carbonyl group in position C4 of ring C, absence of conjugation between the carbons bearing the C2 = C3 double bond and the said ring, presence of a catechol group in ring B and characteristic hydroxylation in positions 5 and 7 of ring A are the structural characteristics that determine the highest degree of genoprotection. Additionally, a certain degree of polymerization of this flavonoid monomer, but maintaining significant levels of monomers and dimers, contributes to increasing the degree of genoprotection in the animals studied at both times of their administration (before and after exposure to X-rays).

Baicalin Promotes Chondrocyte Viability and the Synthesis of Extracellular Matrix through TGF-β/Smad3 Pathway in Mouse Chondrocytes

Background: Osteoarthritis (OA) is epidemic in the elderly people as a common chronic joint disease. By now, drug and surgical treatments are two main therapies for OA worldwidely. Baicalin (BA) is a flavonoid monomer extracted from Scutellaria baicalensis Georgi and is reported that BA has anti-inflammatory, anti-deformation and anti-bacterial effects. Methods: Micromass culture, alcian blue and Safran O (SO)/fast green staining were used to investigate chondrocyte viability and ECM synthesis in chondrocytes of all groups. The expression of SOX9 and Smad3 in chondrocytes of all groups were detected by western blot and RT-qPCR, the expression of aggrecan (AGG), type II collagen (Col2α), MMP9/13 and ADAMTS5 were detected by RT-qPCR. In current study, we demonstrated that BA neutralized the down-regulation of chondrocyte viability and extracellular matrix (ECM) secretion, including AGG and Col2α, induced by IL-1β. As the key regulators of ECM, the down-regulation of SOX9, and the up-regulation of MMP9/13 and ADAMTS5 induced by IL-1β were abolished by BA. Moreover, BA increased the nuclear translocation and phosphorylation of Smad3, one key mediator of TGF-β/Smads pathway. Interestingly, the addition of Smad3 inhibitor SIS3 reversed the promotions of BA on chondrocyte viability, ECM secretion, SOX9 expression, Smad3 nuclear translocation and Smad3 phosphorylation, and the down-regulation of BA on the expressions of MMP9/13 and ADAMTS5. Conclusions: These results imply that BA can protect chondrocytes against IL-1β-induced inflammatory injury through the acceleration of Smad3 phosphorylation and nuclear translocation in chondrocytes. This study demonstrates that BA may be a potential drug for OA clinical treatment.

Rapid Detection of Kaempferol Using Surface Molecularly Imprinted Mesoporous Molecular Sieves Embedded with Carbon Dots

This work demonstrates rapid sensing of kaempferol using active sensing material synthesized using the one-pot surface-imprinting synthesis method. This sensor consisted of molecularly imprinted polymer (MIP) consisting of mesoporous molecular sieves (SBA-15) loaded with carbon dots (CDs). Fourier transform infrared (FT-IR) spectroscopy confirmed successful incorporation of CDs onto the surface of imprinted mesoporous molecular sieves. Ordered hexagonal arrays of CDs@SBA-15@MIP mesopore structure were confirmed with transmission electron microscopy. Fluorescence intensity of CDs@SBA-15@MIP composites linearly correlated with kaempferol content in the 0.05–2 mg/L range. Detection limit was 14 μg/L. MIPs were used for efficient detection of kaempferol in fruit and vegetable samples with recovery values from 80% to 112%. The method has high sensitivity, low cost, good selectivity, and many application potentials useful for research and development of flavonoid monomer presence in food.

Isoliquiritigenin Ameliorates Acute Pancreatitis in Mice via Inhibition of Oxidative Stress and Modulation of the Nrf2/HO-1 Pathway

Oxidative stress plays a crucial role in the pathogenesis of acute pancreatitis (AP). Isoliquiritigenin (ISL) is a flavonoid monomer with confirmed antioxidant activity. However, the specific effects of ISL on AP have not been determined. In this study, we aimed to investigate the protective effect of ISL on AP using two mouse models. In the caerulein-induced mild acute pancreatitis (MAP) model, dynamic changes in oxidative stress injury of the pancreatic tissue were observed after AP onset. We found that ISL administration reduced serum amylase and lipase levels and alleviated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. Meanwhile, ISL decreased the oxidative stress injury and increased the protein expression of the Nrf2/HO-1 pathway. In addition, after administering a Nrf2 inhibitor (ML385) or HO-1 inhibitor (zinc protoporphyrin) to block the Nrf2/HO-1 pathway, we failed to observe the protective effects of ISL on AP in mice. Furthermore, we found that ISL mitigated the severity of pancreatic tissue injury and pancreatitis-associated lung injury in a severe acute pancreatitis model induced by L-arginine. Taken together, our data for the first time confirmed the protective effects of ISL on AP in mice via inhibition of oxidative stress and modulation of the Nrf2/HO-1 pathway.

Changes of the Flavonoid and Phenolic Acid Content and Antioxidant Activity of Tartary Buckwheat Beer during the Fermentation

Through determinated the changes of composition and activity during the fermentation period of buckwheat beer , then analyzed the relationship by used SAS 9.0 software. Determined the monomer flavonoid, monomer phenolic acids by HPLC, antioxidant activity by against the ABTS and DPPH. The results show that the amount of total flavonoid (from 0.607±0.047 g·L-1to 0.519±0.038 g·L-1), total phenolic acids (from 0.690±0.060 g·L-1to 0.395±0.034 g·L-1) change during fermentation . Tartary buckwheat beer exhibits strong DPPH (103.904±0.361 VCEAC mg·L-1) and ABTS (25.018±0.268 VCEAC mg·L-1) radical scavenging activities.The rutin, quercetin, ferulic acid, caffeic acid, protocatechuic acid,and p-coumaric acid show a downward trend, however,the isoquercitrin, gallic acid display the rising trend. At the same time,the regression equation as Y2( Total phenolic) = 0.31595 + 2.10834X5(Quercetin)(P<0.05), Y3( ABTS[VCEA ) = 47.75299 23.78253X8(Ferulic acid)(P,0.05).

Flavonoid Composition of Three Genotypes of Dry Bean (Phaseolus vulgaris) Differing in Seedcoat Color

Three dry bean (Phaseolus vulgaris L.) genotypes differing in seedcoat color, mineral brown (P C D J G B v), yellow brown (P C D J G b v), and pale greenish yellow (P C D J g b v), were analyzed phytochemically. Kaempferol 3-O-β-d-glucoside (astragalin) was isolated and identified by nuclear magnetic resonance spectroscopy from all three genotypes, and was the main flavonoid monomer present. Flavonoid polymers (condensed tannins) were detected by thin layer chromatography, but anthocyanins were not detected in the three genotypes. High pressure liquid chromatography analyses indicated that astragalin was present at similar concentrations in pale greenish yellow and mineral brown genotypes, but was significantly lower in yellow brown. Presently, we do not know the functions of the G and B color genes, although the presence of astragalin in the three genotypes studied indicates these genes do not appear to act in a qualitative manner with regard to astragalin production, but may control the amount of astragalin present. Subtle differences in color between these genotypes may be due to the amount and type of tannins which have secondarily polymerized with phenolics and flavonoid monomers.