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Abstract Glucose exposure induces toxic effects on the function of the pancreatic islets. Moreover, myricitrin as a flavonoid glycoside may have favorable effects on insulin secretion of Langerhans islets. The present study aimed to investigate the effect of Myricitrin and its solid lipid nanoparticles (SLN) on the insulin secretion as well as the content of isolated pancreatic islets from male mice. In this experimental study, Langerhans islets were separated from adult male NMRI mice using the collagenase method. The insulin secretion and content of islets were assessed in glucose-containing medium (2.8, 5.6, and 16.7mM). Further, islets treated were prepared by the administration of Myricitrin and its SLN (1, 3 and 10µM). Myricitrin 3µM, and SLN containing Myricitrin 3 and 10µM increased insulin secretion in medium containing glucose concentration 2.8mM. Accordingly, this variable increased in Myricitrin 3 and 10µM, SLN containing Myricitrin 1, 3, and 10µM utilization as well as glucose concentration 5.6mM. Afterward, the insulin secretion increased in medium containing 16.7mM glucose after the addition of Myricitrin and SLN containing Myricitrin 1, 3, and 10µM. Also, the insulin content increased in Myricitrin and SLN containing Myricitrin 1, 3, and 10µM administered groups in all medium containing glucose concentrations. Myricitrin and its SLN increased islets insulin secretion and content in low, moderate, and high glucose concentration mediums
Subject(s)
Animals , Male , Mice , Pancreas/drug effects , Islets of Langerhans/abnormalities , Insulin Secretion/immunology , Organization and Administration , Nanoparticles , Insulin/adverse effectsABSTRACT
Objective:To explore the effect of myricitrin on the injury of human retinal microvascular endothelial cells (HRMECs) induced by high glucose and its regulation mechanism.Methods:HRMECs were divided into normal control group, high glucose group and 12.5 μg/ml, 25.0 μg/ml and 50.0 μg/ml myricitrin groups.HRMECs transfected with pcDNA and pcDNA-circZNF292, respectively and then cultured in high-glucose medium containing 25 mmol/L D-glucose for 24 hours were assigned as pcDNA group and pcDNA-circZNF292 group.HRMECs transfected with siR-NC and siR-circZNF292, respectively and then cultured in medium containing 50.0 μg/ml myricitrin and 25 mmol/L D-glucose for 24 hours were assigned as myricitrin+ siR-NC group and myricitrin+ siR-circZNF292 group.The cell apoptosis rate was detected by flow cytometry.The concentration of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in cells were detected by enzyme-linked immunosorbent assay (ELISA) kits.The expression levels of circZNF292 and miR-23b-3p were detected by real-time fluorescence quantitative PCR.The targeting relationship between circZNF292 and miR-23b-3p was detected by dual-luciferase reporter assay.The relative expression levels of B-cell lymphoma-2 (bcl-2) and bcl-2-related X protein (bax) were assayed by Western blot.Results:Significant differences were found in the relative expressions of bax and bcl-2 proteins, cell apoptosis rate, MDA concentration, SOD activity, circZNF292 and miR-23b-3p among normal control group, high glucose group and 12.5 μg/ml, 25.0 μg/ml, 50.0 μg/ml myricitrin groups ( F=105.707, 111.835, 74.515, 109.651, 135.020, 219.919, 116.304; all at P<0.001).With the increase of myricitrin concentration, the relative expression levels of bax protein, cell apoptosis rate, MDA concentration and miR-23b-3p in cells gradually decreased, while the relative expression levels of bcl-2 protein, SOD activity and circZNF292 increased, with statistically significant differences among groups with different concentrations of myricitrin (all at P<0.05).In the co-transfected wild-type (WT)-circZNF292 cells, the relative luciferase activity in miR-23b-3p group was 0.35±0.03, which was lower than 0.96±0.09 in microRNA-negative control group, and the difference was statistically significant ( t=11.137, P<0.001).Compared with pcDNA group, the relative expression levels of bcl-2 protein, circZNF292 and MDA concentration in cells of pcDNA-circZNF292 group were significantly increased, and the relative expression levels of bax protein, miR-23b-3p, cell apoptosis rate and SOD activity were significantly decreased (all at P<0.05).The relative expression levels of bax protein, miR-23b-3p, cell apoptosis rate and MDA concentration were reduced and relative expression levels of bcl-2 protein, circZNF292 and SOD activity were enhanced in myricitrin group and myricitrin+ siR-NC group in comparison with high glucose group and myricitrin+ siR-circZNF292 group, showing statistically significant differences (all at P<0.05). Conclusions:Myricitrin can inhibit cell apoptosis and oxidative stress by regulating the expression of circZNF292/miR-23b-3p, thereby reducing the damage of HRMECs induced by high glucose.
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Objective: To test the mosquitocidal potential of leaf extracts of Pouteria campechiana prepared with different solvents and elucidate the structure of an isolated mosquitocidal compound. Methods: The leaf extracts of Pouteria campechiana prepared with three solvents (petroleum benzene, ethyl acetate and acetone) and potential bioactive fractions were tested against various stages of Aedes aegypti and Culex quinquefasciatus by using the WHO protocols, and the chemical profile and its functional groups were identified by GC-MS and Fourier transmission-infrared spectroscopy (FT-IR). The structure of bioactive compound was characterized by nuclear magnetic resonance (NMR) spectral technique. Results: The preliminary phytochemical results revealed the presence of alkaloids, amino acids, flavonoids, quinones, saponins, steroids, tannins, and terpenoids in the acetone extract. A significant toxic potential was observed in the acetone extract against both Aedes aegypti and Culex quinquefasciatus mosquitoes. The acetone extract exhibits remarkable larvicidal (LC50: 12.232 μg/mL and LC90: 63.970 μg/mL), pupicidal (LC50: 18.949 μg/mL and LC,0: 167.669 μg/mL) and adulticidal (LC50: 20.689 μg/mL and LC90: 72.881 μg/mL) effects against Aedes aegypti. Furthermore, the same extract was subjected to isolation of bioactive compound by GC- MS and FT-IR analysis. GC-MS results showed the presence of 5 major compounds, and octacosane (18.440%) was detected as the predominant compound. The FT-IR result of acetone extract demonstrated the presence of various functional groups like alkanes/alkynes, ester, aromatic and amides. The NMR spectrum results of isolated compound were well matched to glycoside linked flavonoids. Based on the chromatography and spectral techniques the isolate molecule was identified as myricitrin by FT-IR and nuclear magnetic resonance spectral data. Conclusion: The isolated compound myricitrin possesses a significant toxic effect in all stages of Aedes aegypti and Culex quinquefasciatus mosquito's with lowest LC50 and LC90 values.
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Objective: To test the mosquitocidal potential of leaf extracts of Pouteria campechiana prepared with different solvents and elucidate the structure of an isolated mosquitocidal compound. Methods: The leaf extracts of Pouteria campechiana prepared with three solvents (petroleum benzene, ethyl acetate and acetone) and potential bioactive fractions were tested against various stages of Aedes aegypti and Culex quinquefasciatus by using the WHO protocols, and the chemical profile and its functional groups were identified by GC-MS and Fourier transmission-infrared spectroscopy (FT-IR). The structure of bioactive compound was characterized by nuclear magnetic resonance (NMR) spectral technique. Results: The preliminary phytochemical results revealed the presence of alkaloids, amino acids, flavonoids, quinones, saponins, steroids, tannins, and terpenoids in the acetone extract. A significant toxic potential was observed in the acetone extract against both Aedes aegypti and Culex quinquefasciatus mosquitoes. The acetone extract exhibits remarkable larvicidal (LC
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ABSTRACT Gout is a destructive arthritis with a high prevalence worldwide. However, the available therapy is not able to increase life quality in many patients. Campomanesia velutina (Cambess) O. Berg, Myrtaceae, is used in Brazilian folk medicine to treat pain, inflammation and rheumatism. The aim of this study was to evaluate the potential of ethanolic and aqueous extracts from C. velutina leaves to treat hyperuricemia and inflammation in gout arthritis model. Ethanolic extract of leaves and aqueous extract of leaves were in vitro assayed on xanthine oxidase inhibitory effect and in vivo on an experimental model of oxonate-induced hyperuricemia in mice, liver xanthine oxidase inhibition and monosodium urate crystal-induced paw edema model. The extracts at both tested doses (100 and 300 mg/kg) reduced serum urate levels. They were also able to inhibit xanthine oxidase in vitro and in vivo, demonstrating that this might be the mechanism of action underlying the urate-lowering effects. In addition, the extracts showed significant anti-inflammatory activity on monosodium urate crystal-induced paw edema, especially aqueous extract (100 and 300 mg/kg) that reduced edema at all evaluated times. Rutin and myricitrin were identified in ethanolic and in aqueous extracts. In this study, myricitrin was able to reduce serum uric acid levels and inhibit liver xanthine oxidase at the dose of 15 mg/kg. The anti-hyperuricemic activity of rutin has been previously reported. Thus, rutin and myricitrin seem to contribute to the observed effects of ethanolic and aqueous extracts. The results demonstrated the ability of aqueous and ethanolic extracts to lower serum urate levels and to reduce edema induced by monosodium urate crystals. Therefore, they may contribute to the management of gout in the future.
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Objective: To establish the ultra performance liquid chromatography (UPLC) fingerprint of Vicia amoena var. angusta and compare the other five different origin varieties of Viciae Amoenae Herba in order to evaluate the quality of the preparation. Methods: Eclipse Plus C18 RRHD column (50 mm×2.1 mm, 1.8 μm) were used with acetonitrile (B) and 0.1% formic acid aqueous solution (A) in gradient elution mode at a flow rate of 0.2 mL/min. The detection wavelength was set at 340 nm and the column was 30℃. The fingerprints for V. amoena var. angusta from 10 different areas were set up, the similarity assay for V. amoena var. angusta from ten different areas was carried out to evaluate their quality by Chinese Materia Medica (CMM) Fingerprint Similarity Evaluation System (2004A edition), and the peaks were identified by comparing the reference substance with LC-MS/MS; Whilie the other origins of five kinds of varieties of Viciae Amoenae Herba were compared and identified in the same condition. Results: UPLC fingerprints for V. amoena var. angusta were established, six chromatographic peaks among 15 common peaks were identified by UPLC-ESI-Q-TOF-MS and be intended to be chlorogenic acid, myricitrin, hyperoside, isoquercitrin, kaempferit-rin, and quercitrin. UPLC fingerprint mutual pattern of other five kinds of origins varieties of Viciae Amoenae Herba and V. amoena var. angusta had obvious differences. Conclusion: This method is simple, rapid, stable, and reproducb1e, and could be used for the full quality evaluation of Viciae Amoenae Herba.
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OBJECTIVE: To study flavonoids from the leaves of Zelkova serrata. METHODS: The leaves were extracted with 70% ethanol by continuous thermal reflux. The extract was separated and purified by silica gel column chromatography, polyamide column chromatography, preparative TLC and other isolation techniques. Their structures were identified by their physical properties and spectroscopic data. RESULTS: Eight flavonoids were isolated and identified as myricetin (1), dihydromyricetin (2), quercetin (3), myricitrin(4), myricetin-3-O-β-D-xyloside(5), quercetin-3-O-β-D-xyloside(6), quercitrin(7), and rutin(8). CONCLUSION: All compounds were isolated from Schneider Zelkova leaves for the first time.
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Myricitrin was isolated as the major constituent from Myrcia splendens (2 g %) and Myrcia palustris (0.5g %) of their fractions soluble in ethyl acetate. The presence of this compound was confirmed by chromatographic analyses using HPLC-DAD. The antioxidant activity was measured using reducing power in relation to the reduction of iron (III) to iron (II) ions and DPPH radical scavenging assay. The ethyl acetate and butanol fractions showed the highest antioxidant activity for both species. In relation to the ability of the sample to scavenge DPPH radicals the EC50 values were 8.44 and 9.35 μg/ mL for M. splendens and 17.83 and 15.34 μg/ mL for M. palustris for the ethyl acetate and butanol fractions, respectively. The antioxidant activity may be related to the myricitrin in these extracts that showed an EC50 = 13.93 μg/mL.
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Objective: To study the chemical constituents from the barks of Mangifera indica. Methods: The constituents were separated and purified by different methods of chromatography, and their structures were elucidated by IR, MS, 1D and 2D NMR techniques. Results: Six compounds were isolated from the barks of M. indica. Their structures were identified as mangiferone (1), mangiferin (2), myricetin (3), myricitrin (4), rutin (5), and quercetin (6). Conclusion: Mangiferone (1) is a new diarylheptanoid compound isolated from the barks of M. indica. © 2013 Tianjin Press of Chinese Herbal Medicines.
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Campomanesia velutina (Cambess) O. Berg, Myrtaceae, popularly known as "gabiroba" or "guavira", is used in traditional Brazilian medicine to treat several diseases, including inflammation and rheumatism. Extraction and isolation from leaves of the plant afforded the active compound myricetin 3-O-rhamnoside, also known as myricitrin. The ethanolic extract of leaves of C. velutina and its ethyl acetate and methanolic fractions were evaluated in inflammation (carrageenan-induced paw oedema) and analgesic models (acetic acid-induced abdominal writhing and hot plate test). Moreover, the ethanolic extract, its fractions and the isolated compound were also in vitro evaluated for their ability to modulate NO, TNF-α and IL-10 production from J774A.1 macrophages stimulated by LPS/IFN-γ. In vivo assays showed remarkable anti-inflammatory activity of ethanolic extract, ethyl acetate and methanolic fractions. The antinociceptive activity of ethanolic extract and A was demonstrated in acetic acid-induced abdominal writhing test. In vitro assays demonstrated that ethyl acetate and methanolic fractions fraction and myricitrin inhibited NO production from macrophages J774A.1. Also Myricitrin induced production of IL-10 anti-inflammatory cytokine. None of the samples was able to inhibited TNF-α production. The results demonstrated for the first time the anti-inflammatory and antinociceptive activity of C. velutina. .
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Myrcia uniflora Barb. Rodr., Myrtaceae, popularly known as "pedra-hume-caá" in Brazil, is sold as dry extracts in capsules or as tinctures for the treatment of diabetes mellitus. Previous phytochemical studies on this species described the occurrence of the flavonoids mearnsitrin and myricitrin. In the present study, the chromatographic profiles of M. uniflora leaves and commercial extracts were determined using HPLC-PAD. Myricitrin was used as an external standard in the development and validation of the HPLC method. The proposed method is simple, rapid and reliable and can be successfully applied in industry for standardization of herbs and phytomedicines commercialised in Brazil as "pedra-hume-caá".
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AIM:To study the chemical constituents of the root of Myrica nana cheval.METHODS:The constituents were separated and purified by different methods of chromatography,and their structures were elucidated by UV,IR,GM and NMR.RESULTS:Seven compounds were isolated from the root of Myrica nana cheval.Their structures were identified as ?-sitosterol(1),myricanol(2),myricanone(3),ursolic acid(4),quercetin(5),myricetin(6)and myricitrin(7).CONCLUSION:Except for 5,6 and 7,the other compounds were obtained from this plant for the first time.