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1.
Regul Toxicol Pharmacol ; 140: 105343, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36773715

RESUMO

alpha-Glycosyl isoquercitrin (AGIQ) is a flavonoid that possesses antioxidant and tumor suppressive capabilities and is marketed as a food additive in Japan. The aim of this study was to assess the potential for oral chronic toxicity and carcinogenicity of AGIQ in male and female Sprague Dawley rats following up to 5.0% dietary exposure. In the chronic toxicity study, rats were exposed to AGIQ or vehicle for one year with a 6-month interim termination point; for the carcinogenicity study, rats were treated for 24 months. No signs of AGIQ-related toxicity clinically or histologically were observed for up to one year except for yellow discoloration of bone. In the carcinogenicity study, a statistically significant increase in the incidence of malignant glioma of the brain or spinal cord was observed in female rats exposed to 5.0% AGIQ compared to those exposed to control feed. A Scientific Advisory Panel of experienced neuropathologists reviewed the gliomas (routine stains and glial cell markers) and concluded that the gliomas were a rare, spontaneous, rat-specific neoplasm: malignant microglial tumor. The lesions could not definitively be attributed to AGIQ exposure and have limited implications with respect to predicting human cancer risk.


Assuntos
Glioma , Quercetina , Ratos , Masculino , Feminino , Humanos , Animais , Ratos Sprague-Dawley , Quercetina/toxicidade , Antioxidantes , Glioma/induzido quimicamente
2.
Environ Toxicol ; 38(1): 49-69, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36125228

RESUMO

We investigated the effect of lipopolysaccharide (LPS)-induced maternal immune activation used as a model for producing neurodevelopmental disorders on hippocampal neurogenesis and behaviors in rat offspring by exploring the antioxidant effects of alpha-glycosyl isoquercitrin (AGIQ). Pregnant Sprague-Dawley rats were intraperitoneally injected with LPS (50 µg/kg body weight) at gestational days 15 and 16. AGIQ was administered in the diet to dams at 0.5% (w/w) from gestational day 10 until weaning at postnatal day 21 and then to offspring until adulthood at postnatal day 77. During postnatal life, offspring of LPS-injected animals did not show neuroinflammation or oxidative stress in the brain. At weaning, LPS decreased the numbers of type-2b neural progenitor cells (NPCs) and PCNA+ proliferating cells in the subgranular zone, FOS-expressing granule cells, and GAD67+ hilar interneurons in the dentate gyrus. In adulthood, LPS decreased type-1 neural stem cells, type-2a NPCs, and GAD67+ hilar interneurons, and downregulated Dpysl3, Sst, Fos, Mapk1, Mapk3, Grin2a, Grin2b, Bdnf, and Ntrk2. In adults, LPS suppressed locomotor activity in the open field test and suppressed fear memory acquisition and fear extinction learning in the contextual fear conditioning test. These results indicate that mid-gestation LPS injections disrupt programming of normal neurodevelopment resulting in progressive suppression of hippocampal neurogenesis and synaptic plasticity of newborn granule cells by suppressing GABAergic and glutamatergic neurotransmitter signals and BDNF/TrkB signaling to result in adult-stage behavioral deficits. AGIQ ameliorated most aberrations in hippocampal neurogenesis and synaptic plasticity, as well as behavioral deficits. Effective amelioration by continuous AGIQ treatment starting before LPS injections may reflect both anti-inflammatory and anti-oxidative stress effects during gestation and neuroprotective effects of continuous exposure through adulthood.


Assuntos
Transtornos do Neurodesenvolvimento , Efeitos Tardios da Exposição Pré-Natal , Quercetina , Animais , Feminino , Gravidez , Ratos , Fator Neurotrófico Derivado do Encéfalo , Extinção Psicológica , Medo , Hipocampo , Lipopolissacarídeos/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos Sprague-Dawley , Quercetina/análogos & derivados , Quercetina/farmacologia , Neuroproteção , Transtornos do Neurodesenvolvimento/induzido quimicamente , Transtornos do Neurodesenvolvimento/prevenção & controle
3.
Int J Mol Sci ; 23(23)2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36499113

RESUMO

Quercetin and its glycosides, such as isoquercitrin or rutin, are among the most ubiquitous flavonoids present in plants. They possess numerous health-promoting properties, whose applicability is, however, limited by poor water solubility and absorption issues. Enzymatically modified isoquercitrin (EMIQ) is an isoquercitrin derivative obtained from rutin via enzymatic transformations that greatly enhance its bioavailability. Due to advantageous reports on its safety and bioactivity, EMIQ is currently gaining importance as a food additive and a constituent of dietary supplements. This review summarizes the thus-far-conducted investigations into the metabolism, toxicity, biological properties, and molecular mechanisms of EMIQ and presents a comprehensive characterization of this valuable substance, which might represent the future of flavonoid supplementation.


Assuntos
Quercetina , Rutina , Quercetina/farmacologia , Disponibilidade Biológica , Rutina/farmacologia , Glicosídeos , Solubilidade
4.
Arch Toxicol ; 94(7): 2413-2421, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32388820

RESUMO

Previous rat toxicity studies of alpha-glycosyl isoquercitrin (AGIQ), a water-soluble flavonol glycoside derived from rutin, revealed systemic yellow bone discoloration. This investigative study was conducted to determine the AGIQ metabolite(s) responsible for the discoloration. Female Sprague-Dawley rats were administered dietary AGIQ at doses of 0%, 1.5%, 3.0%, or 5.0% (0, 1735.0, 3480.8, and 5873.7 mg/kg/day, respectively) for 14 days, followed by a 14- or 28-day recovery period. Measurements of quercetin in urine and quercetin, quercetin 3-O-glucuronide, kaempferol, and 3-o-methylquercetin metabolites of AGIQ in bone (femur), white and brown fat, and cerebrum samples were conducted following the exposure period and each recovery period. Gross examination of the femur revealed yellow discoloration that increased in intensity with dose and was still present in a dose-related manner following both recovery periods. Quercetin, at levels correlating with AGIQ dose, was measured in the urine following the 14-day exposure period and, at lower concentrations, 14 or 28 days following cessation of AGIQ exposure. All four metabolites were present in a dose-dependent manner in the femur following 14 days of dietary exposure; only quercetin, quercetin 3-O-glucuronide, and 3-o-methylquercetin were present during the recovery periods. Quercetin, quercetin 3-O-glucuronide, and 3-o-methylquercetin were detected in white fat (along with kaempferol), brown fat (excluding quercetin due to analytical interference), and cerebrum samples, indicating systemic availability of the metabolites. Collectively, these data implicate quercetin, quercetin 3-O-glucuronide, or 3-o-methylquercetin (or a combination thereof) as the most likely metabolite of AGIQ causing the yellow discoloration of bone in rats administered dietary AGIQ.


Assuntos
Fêmur/efeitos dos fármacos , Transtornos da Pigmentação/induzido quimicamente , Pigmentação/efeitos dos fármacos , Quercetina/toxicidade , Animais , Biotransformação , Feminino , Fêmur/patologia , Transtornos da Pigmentação/patologia , Quercetina/análogos & derivados , Quercetina/metabolismo , Ratos Sprague-Dawley , Fatores de Tempo
5.
J Toxicol Pathol ; 33(4): 247-263, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33239843

RESUMO

We previously reported that exposure to α-glycosyl isoquercitrin (AGIQ) from the fetal stage to adulthood facilitated fear extinction learning in rats. The present study investigated the specific AGIQ exposure period sufficient for inducing this behavioral effect. Rats were dietarily exposed to 0.5% AGIQ from the postweaning stage to adulthood (PW-AGIQ), the fetal stage to postweaning stage (DEV-AGIQ), or the fetal stage to adulthood (WP-AGIQ). Fear memory, anxiety-like behavior, and object recognition memory were assessed during adulthood. Fear extinction learning was exclusively facilitated in the WP-AGIQ rats. Synaptic plasticity-related genes showed a similar pattern of constitutive expression changes in the hippocampal dentate gyrus and prelimbic medial prefrontal cortex (mPFC) between the DEV-AGIQ and WP-AGIQ rats. However, WP-AGIQ rats revealed more genes constitutively upregulated in the infralimbic mPFC and amygdala than DEV-AGIQ rats, as well as FOS-immunoreactive(+) neurons constitutively increased in the infralimbic cortex. Ninety minutes after the last fear extinction trial, many synaptic plasticity-related genes (encoding Ephs/Ephrins, glutamate receptors/transporters, and immediate-early gene proteins and their regulator, extracellular signal-regulated kinase 2 [ERK2]) were upregulated in the dentate gyrus and amygdala in WP-AGIQ rats. Additionally, WP-AGIQ rats exhibited increased phosphorylated ERK1/2+ neurons in both the prelimbic and infralimbic cortices. These results suggest that AGIQ exposure from the fetal stage to adulthood is necessary for facilitating fear extinction learning. Furthermore, constitutive and learning-dependent upregulation of synaptic plasticity-related genes/molecules may be differentially involved in brain regions that regulate fear memory. Thus, new learning-related neural circuits for facilitating fear extinction can be established in the mPFC.

6.
Life Sci ; 344: 122561, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38490298

RESUMO

AIMS: Increasing evidence suggests a link between gut microbial dysbiosis and the pathogenesis of depression. Alpha-glycosyl isoquercitrin (AGIQ), consisting of isoquercitrin and its glycosylated quercetin, has beneficial effects on the gut microbiome and brain function. Here, we detected the potential antidepressant impact of a four-week administration of AGIQ and its underlying mechanisms using a mouse model of depression. MAIN METHODS: Male C57BL/6 mice were orally administered AGIQ (0.05 % or 0.5 % in drinking water) for 28 days; subchronic social defeat stress was performed in the last 10 days. Behavior tests were conducted to assess anxiety and depressive-like behaviors. Additionally, evaluations encompassed 5-hydroxytryptamine (5-HT) levels, the gut microbiota composition, lipopolysaccharide (LPS) concentrations, short-chain fatty acids levels, and intestinal barrier integrity changes. KEY FINDINGS: AGIQ significantly alleviated depression-like behaviors and increased hippocampal 5-HT levels. Further, AGIQ mitigated stress-induced gut microbial abnormalities and reduced the levels of LPS in the serum, which affected the relative gene expression levels of 5-HT biosynthesis enzymes in vitro. Furthermore, AGIQ reversed the reduced butyrate levels in cecal contents and improved the impaired intestinal barrier by increasing the expression of colonic zonula occluden-1 (ZO-1) and occludin, thereby decreasing LPS leakage. SIGNIFICANCE: Our results suggest that AGIQ could improve stress-induced depression by regulating the gut microbiome, which inhibits LPS production and maintains the gut barrier. This is the first report on the potential effect of AGIQ on depression via the gut microbiota-brain axis, shedding new light on treatment options.


Assuntos
Eixo Encéfalo-Intestino , Quercetina , Quercetina/análogos & derivados , Animais , Camundongos , Masculino , Quercetina/farmacologia , Depressão/tratamento farmacológico , Lipopolissacarídeos , Derrota Social , Serotonina , Camundongos Endogâmicos C57BL
7.
J Agric Food Chem ; 71(43): 15991-16002, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37861708

RESUMO

Alpha-glycosyl isoquercitrin (AGIQ), composed of isoquercitrin and glycosylated quercetin, has multiple biological effects. Here, we further examined the influence of AGIQ on brain function and provided its potential mechanism. Male C57BL/6 mice were treated with 0, 0.005, and 0.05% AGIQ in drinking water for 4 weeks prior to behavioral testing. Behavior tests showed that 0.05% AGIQ treatment significantly improved learning and memory function without affecting emotion. In the hippocampus, the gene expression of antioxidative defense enzymes was upregulated after 0.05% AGIQ treatment. In contrast, AGIQ caused significant alterations in the microbial abundance of genera Akkermansia, Bifidobacterium, and Alistipes associated with memory function. Metabolomics analysis identified that taurine concentration was significantly increased in serum and hippocampus from AGIQ-treated mice. The correlation analysis suggested that elevated serum taurine levels were closely related to the abundance of Akkermansia, indicating the underlying crosstalk of gut microbiota and serum metabolites. In vitro fecal culture further demonstrated that AGIQ could increase the level of Akkermansia. Taurine could exert antioxidant activity in SH-SY5Y neuroblastoma cell lines in vitro. Finally, vancomycin-induced alterations of gut microbiota attenuated the taurine increases in the serum and the antioxidant gene level in the hippocampus by AGIQ. Taken together, it is likely that AGIQ could increase genus Akkermansia abundance and ultimately increase taurine levels in serum and hippocampus to improve learning and memory function, relying on the gut microbiota-blood-brain axis. Our results supply a new view for understanding effects of AGIQ on brain function.


Assuntos
Microbioma Gastrointestinal , Neuroblastoma , Camundongos , Masculino , Humanos , Animais , Quercetina , Barreira Hematoencefálica , Camundongos Endogâmicos C57BL , Antioxidantes , Taurina
8.
J Chem Neuroanat ; 133: 102336, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37678702

RESUMO

This study compared the effects of embryonic and neonatal lipopolysaccharides (LPS) exposure (E-LPS and N-LPS) on oligodendrocyte (OL) differentiation in the hippocampus of male rats and explored the protective effect of the antioxidant alpha-glycosyl isoquercitrin (AGIQ). Using SD rats, LPS exposure occurred either intraperitoneally in dams between gestational days 15 and 16 (50 µg/kg body weight/time) or in male pups on postnatal day (PND) 3 (1 mg/kg body weight). Under both regimens, AGIQ at 0.5% (w/w) was supplemented, to dams from the gestation period (before LPS exposure) until weaning on PND 21 and to male offspring from weaning until PND 77 (adulthood). Compared with a control treatment, E-LPS treatment resulted in fewer NG2+ OL progenitor cells (OPCs) and an upregulation of Tcf4 at PND 6; by PND 21, low NG2+ OPC number persisted, but OLIG2+ OL lineage cells increased, while CNPase+ mature OLs counts were unchanged. By contrast, N-LPS treatment resulted in fewer OLIG2+ cells and an upregulation of Bmp4 at PND 6; by PND 21, NG2+ OPCs decreased, while GFAP+ astrocytes increased at both PND 6 and 21. After N-LPS treatment, Kl and Yy1 were downregulated and there were fewer Klotho+ and CNPase+ cells at PND 21. Results suggest that E-LPS treatment facilitates OPC differentiation into pre- and immature OLs until weaning, while N-LPS treatment suppresses OPC differentiation into mature OLs but facilitates astrocyte generation; however, these changes spontaneously recovered by adulthood under both regimens. AGIQ treatment ameliorated the effects of LPS treatment of both regimens, suggesting that LPS-induced disruption of OPC/OL differentiation occurs via neuroinflammation.


Assuntos
Hipocampo , Lipopolissacarídeos , Ratos , Animais , Masculino , Lipopolissacarídeos/farmacologia , Ratos Sprague-Dawley , Antioxidantes/farmacologia , Diferenciação Celular/fisiologia , Oligodendroglia , Peso Corporal , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/farmacologia
9.
J Toxicol Sci ; 48(3): 121-137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36858638

RESUMO

This study investigated the role of neuroinflammation in a lipopolysaccharides (LPS)-induced cognitive dysfunction model in rats using an antioxidant, α-glycosyl isoquercitrin (AGIQ). Six-week-old rats were dietary treated with 0.5% (w/w) AGIQ for 38 days, and LPS at 1 mg/kg body weight was administered intraperitoneally once daily on Days 8 and 10. On Day 11, LPS alone increased or tended to increase interleukin-1ß and tumor necrosis factor-α in the hippocampus and cerebral cortex. Immunohistochemically, LPS alone increased the number of Iba1+ and CD68+ microglia, and GFAP+ astrocytes in the hilus of the hippocampal dentate gyrus (DG). AGIQ treatment decreased or tended to decrease brain proinflammatory cytokine levels and the number of CD68+ microglia in the DG hilus. In the contextual fear conditioning test during Day 34 and Day 38, LPS alone impaired fear memory acquisition, and AGIQ tended to recover this impairment. On Day 38, LPS alone decreased the number of DCX+ cells in the neurogenic niche, and AGIQ increased the numbers of PCNA+ cells in the subgranular zone and CALB2+ hilar interneurons. Additionally, LPS alone decreased or tended to decrease the number of synaptic plasticity-related FOS+ and COX2+ granule cells and AGIQ recovered them. The results suggest that LPS administration induced acute neuroinflammation and subsequent impairment of fear memory acquisition caused by suppressed synaptic plasticity of newborn granule cells following disruptive neurogenesis. In contrast, AGIQ exhibited anti-inflammatory effects and ameliorated LPS-induced adverse effects. These results suggest that neuroinflammation is a key factor in the development of LPS-induced impairment of fear memory acquisition.


Assuntos
Medo , Memória , Doenças Neuroinflamatórias , Quercetina , Animais , Ratos , Lipopolissacarídeos , Quercetina/análogos & derivados , Quercetina/farmacologia
10.
J Chem Neuroanat ; 128: 102219, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36572259

RESUMO

Polyinosinic-polycytidylic acid (PIC) provides a model of developmental neuropathy by inducing maternal immune activation. We investigated the effects of an antioxidant, alpha-glycosyl isoquercitrin (AGIQ), on PIC-induced developmental neuropathy in rats, focusing on postnatal hippocampal neurogenesis. On gestational day 15, PIC at 4 mg/kg body weight was administered to dams intravenously. AGIQ either at 0.25% or 0.5% was administered through the diet to dams from gestational day 10 until weaning on day 21 post-delivery and, thereafter, to offspring until postnatal day 77 (adult stage). At weaning, the numbers of TBR2+ cells and PCNA+ cells in the subgranular zone and reelin+ cells in the dentate gyrus hilus in offspring of dams treated with PIC only were decreased compared with untreated controls. In contrast, 0.5% AGIQ ameliorated these changes and increased the transcript levels of genes related to signaling of reelin (Reln and Vldlr), growth factors (Bdnf, Cntf, Igf1, and Igf1r), and Wnt/ß-catenin (Wnt5a, Lrp6, Fzd1, and Fzd3). In adults, AGIQ increased the number of FOS+ granule cells at 0.25% and the transcript levels of NMDA-type glutamate receptor genes, Grin2a and Grin2b, at 0.25% and 0.5%, respectively. These results suggest that mid-gestation PIC treatment decreased the abundance of type-2b neural progenitor cells (NPCs) by reducing NPC proliferation in relation with suppression of reelin signaling at weaning. We suggest that AGIQ ameliorated the PIC-induced suppressed neurogenesis by enhancing reelin, growth factor, and Wnt/ß-catenin signaling at weaning to rescue NPC proliferation and increased synaptic plasticity by enhancing glutamatergic signaling via NMDA-type receptors after maturation.


Assuntos
Poli I-C , Efeitos Tardios da Exposição Pré-Natal , Animais , Ratos , Gravidez , Feminino , Humanos , beta Catenina/metabolismo , N-Metilaspartato/metabolismo , N-Metilaspartato/farmacologia , Apoptose , Hipocampo/metabolismo , Neurogênese , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Giro Denteado
11.
Chem Biol Interact ; 351: 109767, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34863679

RESUMO

The present study investigated the role of neuroinflammation and brain oxidative stress induced by neonatal treatment with lipopolysaccharides (LPS) on the development of autism spectrum disorder (ASD)-like behaviors and disruptive hippocampal neurogenesis in rats by exploring the chemopreventive effects of alpha-glycosyl isoquercitrin (AGIQ) as an antioxidant. AGIQ was dietary administered to dams at 0.25% or 0.5% (w/w) from gestational day 18 until postnatal day (PND) 21 on weaning and then to pups until the adult stage on PND 77. The pups were intraperitoneally injected with LPS (1 mg/kg body weight) on PND 3. At PND 6, LPS alone increased Iba1+ and CD68+ cell numbers without changing the CD163+ cell number and strongly upregulated pro-inflammatory cytokine gene expression (Il1a, Il1b, Il6, Nfkb1, and Tnf) in the hippocampus, and increased brain malondialdehyde levels. At PND 10, pups decreased ultrasonic vocalization (USV), suggesting the induction of pro-inflammatory responses and oxidative stress to trigger communicative deficits. By contrast, LPS alone upregulated Nfe2l2 expression at PND 6, increased Iba1+, CD68+, and CD163+ cell numbers, and upregulated Tgfb1 at PND 21, suggesting anti-inflammatory responses until the weaning period. However, LPS alone disrupted hippocampal neurogenesis at weaning and suppressed social interaction parameters and rate of freezing time at fear acquisition and extinction during the adolescent stage. On PND 77, neuroinflammatory responses had mostly disappeared; however, disruptive neurogenesis and fear memory deficits were sustained. AGIQ ameliorated most changes on acute pro-inflammatory responses and oxidative stress at PND 6, and the effects on USVs at PND 10 and neurogenesis and behavioral parameters throughout the adult stage. These results suggested that neonatal LPS treatment induced acute but transient neuroinflammation, triggering the progressive disruption of hippocampal neurogenesis leading to abnormal behaviors in later life. AGIQ treatment was effective for ameliorating LPS-induced progressive changes by critically suppressing initial pro-inflammatory responses and oxidative stress.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Transtorno Autístico/tratamento farmacológico , Glicosídeos/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Quercetina/análogos & derivados , Animais , Animais Recém-Nascidos , Transtorno Autístico/induzido quimicamente , Transtorno Autístico/patologia , Giro Denteado/efeitos dos fármacos , Giro Denteado/patologia , Feminino , Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos , Masculino , Neurogênese/efeitos dos fármacos , Doenças Neuroinflamatórias/induzido quimicamente , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/patologia , Teste de Campo Aberto/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Quercetina/uso terapêutico , Ratos Sprague-Dawley , Interação Social/efeitos dos fármacos
12.
Toxicol Rep ; 9: 1291-1296, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518433

RESUMO

Skin sensitization is an important aspect of safety assessment and is a key component in the toxicological evaluation of chemicals. alpha-Glycosyl isoquercitrin (AGIQ), is marketed in Japan as a food additive and is generally recognized as safe (GRAS) by the expert panel of the Flavor and Extract Manufacturers Association (FEMA) in 2005 and the U.S. Food and Drug Administration (FDA) in 2007. The Local Lymph Node Assay (LLNA) was used to assess AGIQ's potential to cause skin sensitization. Results indicate that no excessive irritation was observed after the irritation screen (ear swelling < 25 % and erythema score < 3) when AGIQ was tested at 5 %, 10 %, and 25 % in N, N-dimethyl formamide [DMF]. Based on lack of irritation, AGIQ was further evaluated at 10 %, 25 %, and 50 % in DMF in the main test resulting in stimulation indices of less than the positive threshold of 1.6 i.e., 1.2, 1.4, and 1.2 respectively. Therefore, AGIQ was not a dermal sensitizer in the LLNA.

13.
Food Chem Toxicol ; 151: 112103, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33771599

RESUMO

alpha-Glycosyl Isoquercitrin (AGIQ), is used in Japan as a food additive and was granted generally recognized as safe (GRAS) status in 2005 (FEMA) and 2007 (FDA). The safety and toxicity information for AGIQ is sparse and therefore, the carcinogenicity potential of AGIQ was examined in the CByB6F1-Tg(HRAS)2Jic (rasH2) model. One hundred female and male rasH2 mice, each, were allocated to one of four designated dose groups; 0 (control)%, 1.5%, 3.0% or 5.0% AGIQ. Animals were administered the diets for six months and an additional 10 females and 10 males, each, were administered a positive control, N-methyl-N-nitrosourea (MNU). Body weights and clinical observations were collected. A full screen necropsy, organ weights, clinical chemistry, urinalysis and histopathology were performed. The positive control animals elicited appropriate responses specific to this strain (rasH2) of mice. There were statistically significant sporadic non-dose-dependent changes in clinical chemistries without corresponding pathological correlation. No microscopic AGIQ-related findings were noted; the range of pathology observations were all considered background findings, either specific to rasH2 mice or common to inbred strains of mice. Therefore, under the study conditions, the no-observed-adverse-effect level (NOAEL) was determined to be more than 5.0% (7215.4 mg/kg BW/day in male mice and 14685.5 mg/kg/day in female mice).


Assuntos
Quercetina/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Testes de Carcinogenicidade , Relação Dose-Resposta a Droga , Comportamento Alimentar/efeitos dos fármacos , Feminino , Aditivos Alimentares/administração & dosagem , Aditivos Alimentares/toxicidade , Masculino , Metilnitrosoureia/administração & dosagem , Camundongos , Camundongos Transgênicos , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Quercetina/administração & dosagem , Quercetina/química , Quercetina/toxicidade
14.
J Toxicol Sci ; 44(5): 357-372, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31068541

RESUMO

Developmental hypothyroidism as a model of autism spectrum disorders disrupts hippocampal neurogenesis through the adult stage. The present study investigated the ameliorating effect of postweaning exposure to antioxidant on the hypothyroidism-induced disruptive neurogenesis. Mated female Sprague-Dawley rats were treated with 0 or 10 ppm 6-propyl-2-thiouracil (PTU) as an anti-thyroid agent in drinking water from gestational day 6 to postnatal day (PND) 21 on weaning. PTU-exposed male offspring were fed either basal diet, diet containing α-glycosyl isoquercitrin (AGIQ) at 5,000 ppm or α-lipoic acid (ALA) at 1,000 ppm as an antioxidant from PND 21 to PND 77. PTU-exposure decreased DCX+ and NeuN+ granule cell lineage subpopulations, synaptic plasticity-related FOS+ granule cells, and hilar PVALB+ and GAD67+ GABAergic interneurons, increased hilar SST+ and CALB2+ interneurons, and upregulated Gria3, Otx2, and antioxidant enzyme genes in the dentate gyrus on PND 77. These results suggest disruption of neurogenesis remained in relation with increase of oxidative stress and compensatory responses to the disruption at the adult stage. AGIQ recovered expression of some antioxidant enzyme genes and was effective for restoration of NeuN+ postmitotic granule cells and PVALB+ and SST+ interneurons. In contrast, ALA was effective for restoration of all interneuron subpopulations, as well as postmitotic granule cells, and upregulated Grin2a that may play a role for the restoration. Both antioxidants recovered expression of Otx2 and AGIQ-alone recovered Gria3, suggesting a reversal of disruptive neurogenesis by compensatory responses. Thus, postweaning antioxidant exposure may be effective for ameliorating developmental hypothyroidism-induced disruptive neurogenesis by restoring the function of regulatory system.


Assuntos
Antioxidantes/farmacologia , Hipocampo/efeitos dos fármacos , Hipotireoidismo/fisiopatologia , Neurogênese/efeitos dos fármacos , Quercetina/análogos & derivados , Ácido Tióctico/farmacologia , Animais , Apoptose/efeitos dos fármacos , Proteína Duplacortina , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hipocampo/crescimento & desenvolvimento , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/genética , Masculino , Gravidez , Propiltiouracila , Quercetina/farmacologia , Ratos Sprague-Dawley
15.
Food Chem Toxicol ; 97: 354-366, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27693245

RESUMO

alpha-Glycosyl isoquercitrin (AGIQ) is highly absorbable and has been shown to possess antioxidative properties. Based on a favorable safety profile, it has been confirmed as generally recognized as safe (GRAS) compound by the FDA. Nevertheless, safety and toxicity information for AGIQ is still sparse. Therefore, the aim of this study was to test the safety and toxicokinetics of AGIQ in a 90-day study in 60 male and 60 female Sprague-Dawley rats at dietary doses up to 5%. All animals survived until scheduled euthanasia with no clinical signs of toxicity in any animal. AGIQ was rapidly absorbed with metabolism to quercetin and quercetin glucuronide at all dose levels. Statistically significant changes were noted in some tissue weights and clinical chemistry analytes, without evidence of systemic toxicity. The most prominent finding was systemic dose dependent yellow discoloration of bones of treated animals. However, no changes were observed microscopically, and this observation was concluded as toxicologically insignificant. The overall lack of adverse clinical signs, changes in body weight, feed consumption, clinical pathology parameters, and histopathological endpoints in animals administered AGIQ supports no observable adverse effect levels (NOAEL) of 5.0% in diet for both male and female rats (3461 mg/kg/day and 3867 mg/kg/day, respectively).


Assuntos
Glicosídeos/toxicidade , Quercetina/análogos & derivados , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Glicosídeos/química , Testes Hematológicos , Masculino , Atividade Motora/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Quercetina/química , Quercetina/toxicidade , Ratos , Ratos Sprague-Dawley , Toxicocinética
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