查找使用阿拉丁产品的科研文献

Method for enhancing bioavailability of myricetin based on self-assembly of casein–myricetin nanomicelles

Hui Guo,Yun Fei Chen,Yi Tang,Jun Qing Qian

In order to expand the application in the medical field and enhance pharmacological effects, casein–myricetin nanomicelles were prepared by the self-assembly method and characterised by ultraviolet–visible spectroscopy and Fourier transform infrared spectroscopy. The parameters in self-assembly were optimised according to the factors of particle size, encapsulation yield, and drug loading. The result showed a pH of 5.5, a casein concentration of 2 mg/ml, a mass ratio of casein to myricetin of 8:1, ultrasonic power of 300 W, ultrasonic time of 5 min and ethanol volume of 7 ml were the optimal conditions. The situ cycle intestinal perfusion methods indicated that casein–myricetin nanomicelles can be more easily absorbed by small intestine than myricetin standard sample. Therefore, casein micelles are effective for improving the water solubility of myricetin.

Comparative Analysis of Radical Adduct Formation (RAF) Products and Antioxidant Pathways between Myricetin-3-O-Galactoside and Myricetin Aglycone

Xican Li,Xiaojian Ouyang,Minshi Liang,Dongfeng Chen

The biological process, 3-O-galactosylation, is important in plant cells. To understand the mechanism of the reduction of flavonol antioxidative activity by 3-O-galactosylation, myricetin-3-O-galactoside (M3OGa) and myricetin aglycone were each incubated with 2 mol α,α-diphenyl-β-picrylhydrazyl radical (DPPH•) and subsequently comparatively analyzed for radical adduct formation (RAF) products using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS) technology. The analyses revealed that M3OGa afforded an M3OGa–DPPH adduct (m/z873.1573) and an M3OGa–M3OGa dimer (m/z958.1620). Similarly, myricetin yielded a myricetin–DPPH adduct (m/z711.1039) and a myricetin–myricetin dimer (m/z634.0544). Subsequently, M3OGa and myricetin were compared using three redox-dependent antioxidant analyses, including DPPH•-trapping analysis, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-trapping analysis, and•O2inhibition analysis. In the three analyses, M3OGa always possessed higher IC50values than those of myricetin. Conclusively, M3OGa and its myricetin aglycone could trap the free radical via a chain reaction comprising of a propagation step and a termination step. At the propagation step, both M3OGa and myricetin could trap radicals through redox-dependent antioxidant pathways. The 3-O-galactosylation process, however, could limit these pathways; thus, M3OGa is an inferior antioxidant compared to its myricetin aglycone. Nevertheless, 3-O-galactosylation has a negligible effect on the termination step. This 3-O-galactosylation effect has provided novel evidence that the difference in the antioxidative activities of phytophenols exists at the propagation step rather than the termination step.

Thermal degradation mechanism of myricetin in palmitic acid

Shengxiong Chen,Fan Zhang,Randolph R.J. Arroo,Jesus Simal-Gandara,Hui Cao,Jianbo Xiao

Lipid oxidation governs myricetin degradation in heated palmitic acid. • o-Quinone formation triggers B-ring cleavage and oxidative dimerization. • Carbonyl addition and lipid-derived ester conjugates were detected. • Vitamin C suppresses radical-driven pathways and improves myricetin retention. Dietary polyphenols are susceptible to degradation during high-temperature cooking, yet their transformation behavior in lipid-rich frying systems remains poorly understood. The thermal stability and degradation of myricetin in a simplified palmitic acid model under frying-relevant conditions was investigated. Myricetin degraded rapidly at 180 °C but remained relatively stable at 120 °C. UPLC–QTOF–MS/MS, supported by density functional theory calculations, suggested that myricetin transformation is temperature-dependent but primarily governed by lipid oxidation–derived radical and carbonyl chemistry. Vitamin C markedly delayed myricetin degradation by suppressing radical initiation and limiting o -quinone–centered downstream reactions. These findings highlight lipid oxidation as a key determinant of polyphenol stability during frying and clarify the protective role of antioxidants in lipid-rich thermal processing systems. Download: Download high-res image (202KB) Download: Download full-size image

Mechanistic studies of inhibition on acrolein by myricetin

Dingmin Zhang,Xiaoyun Jiang,Liubang Xiao,Yongling Lu,Shengmin Sang,Lishuang Lv,Wenjiang Dong

Acrolein (ACR) is an unsaturated aldehyde with high activity and toxicity and is produced in vivo and in food. This study investigated the impact of B-ring structure on the trapping of ACR by flavonols and the trapping mechanism and efficacy of ACR by myricetin. Galangin, kaempferol, quercetin, and myricetin, which possess the same A- and C-ring but different numbers of –OH groups on the B-ring, were selected for this study. Our results suggested that increasing the number of –OH groups on the B-ring can enhance the ACR trapping efficacy of flavonol and myrectin was identified as the most active flavonol. The adducts of myricetin with ACR under different ratios and incubation times were analyzed using LC-MS/MS. We also purified and identified the major mono- and di-ACR-myricetin adducts. Furthermore, myricetin could dose-dependently inhibit the formation of ACR in cookies through the formation of mono- and di-ACR adducts.

Deep eutectic solvent extraction of myricetin and antioxidant properties

Junhai Liu,Xiaosha Guo,Qiaowei Miao,Xiaohui Ji,Yinku Liang,Tianjiao Tong

In this study, a response surface method (RSM) was used to optimise the ultrasonic-assisted deep eutectic solvent (DES) extraction of myricetin from myricetin leaves. The results demonstrated that the DES-5 (choline chloride–oxalic acid) system exhibited better extraction results than the other seven DESs prepared. The optimum extraction conditions for myricetin were a DES-5 system with 19% water content of DES, a liquid-to-solid ratio of 37 : 1 mL g−1, an extraction time of 45 min, and an extraction temperature of 72 °C. Under these conditions, the extraction amount of myricetin was 22.47 mg g−1. To optimise the extraction process, the crude myricetin extract was purified, and the optimal conditions were as follows: an AB-8 macroporous adsorption resin was used with an anhydrous ethanol desorption agent. The adsorption rate was 1 BV per h (bed volume per hour), the desorption rate was 1 BV per h, and the desorption capacity was 2 BV (bed volume). The antioxidant properties of the myricetin were also investigated. The results demonstrated that, with an increase in concentration, the scavenging rates of DPPH and ˙OH free radicals increased. Compared to Vc, myricetin had a better scavenging ability for DPPH free radicals, whereas purified myricetin had a better antioxidant effect. At the same concentration, the radical-scavenging rate of the ˙OH radical was slightly higher in myricetin purified by the macroporous adsorption resin than in Vc, and that of the unpurified myricetin was the smallest. Myricetin was purified using a macroporous adsorption resin to improve its antioxidant properties.

Targeting DNA abasic site by myricetin: Sequence-dependent ESIPT emission

Shujuan Xu,Yong Shao,Fei Wu,Guiying Liu,Lingling Liu,Jian Peng,Yanwei Sun

Many efforts have been made for sequence-specific recognition of DNA by small molecules. In this study, abasic site (AP site) in a DNA duplex was found to be targeted by myricetin (Myr), one of the natural 3-hydroxyflavonols. Steady-state and transient-state fluorescence, FRET , and DNA melting experiments confirmed that the AP site binding of Myr favors an emission from its tautomer that is derived from excited-state intramolecular proton transfer (ESIPT) reaction between the 3-OH and 4-carbonyl moieties. The selective recognition of Myr is less dependent on the flanking bases of the AP site, although the ESIPT emission is more lighting up for the DNAs with cytosine and thymine opposite the AP site. Because Myr alone in aqueous solution is non-fluorescent, this selective lighting-up emission is advantageous for developing a practical sensor to target the DNA AP site with a weak fluorescence background. This selective recognition of the AP site by the lighting-up fluorescence response would find wide applications including efficiently evaluating DNA damage/repair and screening antitumor/antioxidation drugs.

Myricetin Inhibits Photodegradation of Profenofos in Water: Pathways and Mechanisms

Nan Zhang,Yawei Yang,Xin Wang,Taozhong Shi,Pei Lv,Qing X. Li,Rimao Hua

Profenofos is a detectable insecticide in the environment with strong toxicity to non-targeted organisms. Photodegradation is a main transformation of profenofos in the environment. Myricetin is a flavonoid that strongly scavenges free radicals. The effect of myricetin on the photodegradation of profenofos was studied. The half-lives (T1/2) of profenofos were 1.7–7.0 and 90 h under artificial light and sunlight. The photolysis rate of profenofos decreased by 1.87–4.72 and 7.62 times with the addition of 20 ratios of myricetin. Free radicals reacting with profenofos were •OH and1O2, and the key free radical was •OH. Myricetin strongly scavenged •OH and1O2which rapidly reacted with profenofos.O-(2-Chlorophenyl)-O-ethyl-S-propyl phosphorothioate (M3) andO-(2-chlorophenyl)-O-ethyl phosphorothioate (M4) were major and new photoproducts of profenofos. According to the Ecological Structure Activity Relationships, photodegradation of profenofos was a detoxification process, but myricetin inhibited the photodegradation of profenofos and its photoproducts. These results highlight the implication of myricetin on the fate and potential risk of profenofos in the environment.

Myricetin ameliorates glucocorticoid-induced osteoporosis through the ERK signaling pathway

Shuli Fan,Xiang Gao,Peng Chen,Xu Li

Myricetin has been reported to promote osteogenic differentiation and inhibit osteoclastogenesis. The aim of this study was to investigate the potential effects of myricetin on glucocorticoid-induced osteoporosis (GIOP) both in vivo and in vitro . Male Sprague-Dawley (SD) rats were given dexamethasone (DEX, 0.1 mg/kg, s.c.) once daily and myricetin (1 mg/kg or 2.5 mg/kg, i.p.) once every other day for a total of five weeks. Body weight was recorded once a week. Bone mineral density (BMD), the activities or levels of bone turnover markers, and histological changes were assessed. MC3T3-E1 cells were incubated with DEX (1 μM) and myricetin (20 μM). Osteoblast proliferation, differentiation and mineralization were evaluated. U0126 was added to evaluate the involvement of the ERK signaling pathway. The results showed that myricetin increased body weight gain and inhibited DEX-induced reduction in BMD, enhanced alkaline phosphatase (ALP) activity, and upregulated osteocalcin (OCN), bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (Runx2) levels, whereas reduced tartrate-resistant acid phosphatase (TRAP) activity and C-terminal telopeptide of type I collagen (CTx) level. In addition, myricetin ameliorated histological changes in the femurs. In our in vitro studies, myricetin promoted osteoblast differentiation and mineralization in DEX-treated MC3T3-E1 cells, accompanied by increases in BMP2, Runx2, ALP, OCN, collagen type I alpha 1 (COL1A1) and osteopontin (OPN) levels. The promotion effects of myricetin on osteogenic differentiation and matrix mineralization were reversed by U0126. These results suggest that myricetin may alleviate DEX-induced osteoporosis by promoting osteogenic differentiation and matrix mineralization via the ERK signaling pathway.

Preparation, characterisation, and pharmacodynamic study of myricetin pH-sensitive liposomes

Chenlu Li,Mengzhe Du,Lingzhi Meng,Michael Adu-Frimpong,Caizhi Gong,Sile Zheng,Wentao Shi,Qilong Wang,Elmurat Toreniyazov,Hao Ji,Xia Cao,Jiangnan Yu,Ximing Xu

Aims Myricetin (MYR) was incorporated into pH-sensitive liposomes in order to improve its bioavailability and anti-hyperuricemic activity.Methods The MYR pH-sensitive liposomes (MYR liposomes) were prepared using thin film dispersion method, and assessed by particle size (PS), polydispersed index (PDI), zeta potential (ZP), encapsulation efficiency, drug loading, and in vitro release rate. Pharmacokinetics and anti-hyperuricemic activities were also evaluated.Results The PS, PDI, ZP, encapsulation efficiency, and drug loading of MYR liposomes were 184.34 ± 1.05 nm, 0.215 ± 0.005, −38.46 ± 0.30 mV, 83.42 ± 1.07%w/w, and 6.20 ± 0.31%w/w, respectively. The release rate of MYR liposomes was higher than free MYR, wherein the cumulative value responded to pH. Besides, the Cmax of MYR liposomes was 4.92 ± 0.20 μg/mL. The level of uric acid in the M-L-H group (200 mg/kg) was reduced by 54.74%w/v in comparison with the model group.Conclusion MYR liposomes exhibited pH sensitivity and could potentially enhance the oral bioavailability and anti-hyperuricemic efficacy of MYR.

Fast Detection of Myricetin With the Use of Dedicated Microdroplets

Zuoren Xiong,Hai Zhang,Yuelan Lu,Lingli Zhang,Weimin Sun,Yongjun Liu

Structure identification of myricetin-phenylacetaldehyde adducts and their potential biological activities

Lei Xie,Tianxing Wang,Ling Chen,Xiaoxi Li

Our previous research discovered that myricetin could effectively inhibit the formation of heterocyclic aromatic amines (HAAs) in cantonese baked foods by trapping phenylacetaldehyde to form adducts. However, the structure and biological activity of these adducts were still unknown. In this study, we identified two myricetin-phenylacetaldehyde adducts from cantonese mooncakes, BYQ-2 and BYQ-3, using pre-HPLC. These adducts were found to be the products of phenylacetaldehyde addition at the C-8 and C-6 positions of myricetin, followed by cyclization with hydroxyl groups at the C-7 and C-5 positions. Antioxidant assays revealed that BYQ-2 and BYQ-3 have stronger radical scavenging abilities than myricetin in the concentration range of 12.5 ∼ 800 μg/mL in the three samples. Additionally, both adducts showed potential health benefits by inhibiting α-glucosidase and CYP450 1A2, enzymes involved in blood sugar regulation and HAAs metabolism. BYQ-2 exhibited the highest inhibitory potency against α-glucosidase and CYP450 1A2 with IC 50 values of 10.32 μg/mL and 5.44 μg/mL, respectively. Theoretical calculations suggested that hydrogen bonding and hydrophobic interactions are the primary forces driving enzyme binding, with BYQ-2 showing the highest binding energies (−7.75 kcal/mol for α-glucosidase and −9.31 kcal/mol for CYP450 1A2). Our findings suggested that myricetin inhibited HAAs in baked foods while also enhancing food safety and providing health benefits through its adduction with small molecule aldehydes. In future research, it is necessary to further evaluate the absorption and metabolic behavior as well as safety of myricetin-HAAs active intermediate adducts at the cellular and animal experimental level.

Physiochemical properties of the complex of myricetin and hydroxypropyl-β-cyclodextrin

H Nan,H Ma,R Zhang,R Zhan

Purpose: To improve the hydrophilic property of myricetin by complexing it with hydroxypropyl-β- cyclodextrin (HP-β-CD)Methods: The complexes of myricetin and HP-β-CD were prepared in both water and ethanol. The physicochemical properties of the complex were investigated by ultraviolet-visible spectrometry (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and x-ray diffractometry (XRD).Results: The content of myricetin in the complex prepared in ethanol (3.71 %) was higher than that prepared in water (1.43 %). Characterization studies indicate that myricetin in the complex was molecularly dispersed in HP-β-CD matrix.Conclusion: Ethanol is the better solvent to prepare the complex of myricetin and hydroxypropyl-β- cyclodextrin. Myricetin and HP-β-CD in the complex are combined by non-covalent bond, and thus did not form a new compound.