• Natural Product Sciences
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• v.17 no.4
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• pp.337-341
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• 2011

An HPLC (high-performance liquid chromatography)-PDA (photodiode array) detection method was established for the determination of naringin, hesperidin and neohesperidin in the fruit of Citrus paradisi and C. grandis. The flavonoids were separated in less than 20 min using an YMC RP 18 column with isocratic elution using acetonitrile and water (23 : 77, v/v) at a flow rate of 1 ml/min, and a PDA detector. The levels of naringin, hesperidin and neohesperidin were 1345.92, 950.62, and 2078.82 ${\mu}g/g$, respectively, in the peel, and 102.43, 59.13, and 86.68 ${\mu}g/g$, respectively, in the flesh of C. paradisi. In C. grandis, the levels of naringin, hesperidin and neohesperidin were 3530.56, 80.00, and 5.26 ${\mu}g/g$, respectively, in the peel, and 59.59, 7.43, and 38.41 ${\mu}g/g$, respectively, in the flesh. The total content was highest in the peel, reaching 0.44% and 0.36% in C. paradisi and C. grandis, respectively, while the flesh contained only 0.025% and 0.011%, respectively. Therefore, the peels of C. paradisi and C. grandis are necessary for the processing and utilization of flavonoids.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.46-51
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• 2006

The inhibitory effects of flavanone derivatives on Helicobacter pylori (HP) growth, infection and VacA toxininduced vacuolation were investigated. Among flavanones tested, ponciretin potently inhibited the growth of HP with a MIC value of 0.01 mg/ml and VacA toxin-induced vacuolation in HeLa cells with $IC_{50}$ value of 0.078 mM. However, other flavanones inhibited neither HP growth nor VacA toxininduced vacuolation. All flavanones tested did not inhibit HP infection to KATO III cells. Ponciretin also inhibited activation of procaspase-3 to caspase-3 in HeLa cell induced by HP VacA toxin, but did not affect Bax and Bcl-2 protein levels. These findings indicate that ponciretin inhibits growth as well as vacuolation by HP VacA toxin, which induces cell death via proteolytic activation of a cascade of caspases.

• BMB Reports
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• v.41 no.1
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• pp.68-71
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• 2008

Flavones are synthesized from flavanones through the action of flavone synthases (FNSs). There are two FNSs, FNS I and II. FNS I is a soluble dioxygenase present in members of the Apiaceae family and FNS II is a membrane bound cytochrome P450 enzyme that has been identified in numerous plant species. In this study, we cloned OsFNS I-1 from rice by RTPCR, expressed it in E. coli, and purified the recombinant protein. By NMR analysis, we found that OsFNS I-1 converted the flavanone (2S)-naringenin into the flavone, apigenin. Moreover, we found that the cofactors oxoglutarate, $FeSO_4$, ascorbate and catalase are required for this reaction. OsFNS I-1 encodes a flavone synthase I. This is the first type I FNS I found outside of the Apiaceae family.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1293-1301
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• 2005

Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant, anticancer, bactericidal, and anti-inflammatory. We carried out anti-herpetic assays on 18 flavonoids in five classes and a virus-induced cytopathic effect (CPE) inhibitory assay, plaque reduction assay, and yield reduction assay were performed. When flavonoids were applied at various concentrations to Vero cells infected by HSV-1 and 2, most of the f1avonoids showed inhibitory effects on virus-induced CPE. Among the flavonoids, EC, ECG (flavanols), genistein (isoflavone), naringenin (flavanone), and quercetin (flavonol) showed a high level of CPE inhibitory activity. The antiviral activity of flavonoids were also examined by a plaque reduction assay. EC, ECG, galangin, and kaempferol showed a strong antiviral activity, and catechin, EGC, EGCG, naringenin, chrysin, baicalin, fisetin, myricetin, quercetin, and genistein showed moderate inhibitory effects against HSV-1. In these experiments, flavanols and flavonols appeared to be more active than flavones. Furthermore, treatment of Vero cells with ECG and galangin (which previously showed strong antiviral activities) before virus adsorption led to a slight enhancement of inhibition as determined by a yield reduction assay, indicating that an intracellular effect may also be involved.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1835-1838
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• 2009

Inhibition of human phenylethanolamine N-methyltransferase (hPNMT) has been proposed as a method for the treatment of several mental processes which related on adrenaline metabolism. We performed in silico screening to identify flavonoid inhibitors of hPNMT using automated docking method and selected 9 inhibitor candidates based on ligand score (LigScore) and binding free energy (${\Delta}G_{bind}$) estimation. Among 9 flavonoid candidates, 7 flavonoids belong to flavones while the rest of them belong to flavanone. All candidates have common chemical features; two hydrogen bond interactions with side chain of Lys75 and backbone carbonyl oxygen of Asn39, and two hydrophobic interactions. One hydrophobic site is formed by Val53, Leu262, and Met258 and the other is made up of Phe182, Ala186, Tyr222, and Val269. This study can be helpful to understand the structural features for inhibition of PNMT and showed flavonoids as promising inhibitor candidates for hPNMT.

• Biomedical Science Letters
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• v.16 no.2
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• pp.83-90
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• 2010

Hesperidin, a member of the flavanone group of flavonoids, can be isolated in large amounts from the rinds of some citrus species [e.g., Citrus aurantium L. (bitter orange), Citrus sinensis L. (sweet orange) and Citrus unshiu Marcov. (satsuma mandarin)], and has been reported to have anticarcinogenic, antihypotensive and antimicrobial properties. Despite the efficacy of these polyphenolic compounds as immune modulators, the effects of the flavonoids are poorly understood about allergic effect. In this study, we investigated whether hesperidin could influence on Th1 and Th2 balance. Allergic reactions included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung tissue around blood vessels and airways, airway luminal narrowing, the development of airway hyper-responsiveness (AHR). The administration of hesperidin before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that hesperidin plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of hesperidin in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of hesperidin.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.699-706
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• 2006

The present study evaluated antioxidant and neuroprotective activities of hesperidin, a flavanone mainly isolated from citrus fruits, and its aglycone hesperetin using cell-free bioassay system and primary cultured rat cortical cells. Both hesperidin and hesperetin exhibited similar patterns of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. While hesperidin was inactive, hesperetin was found to be a potent antioxidant, inhibiting lipid peroxidation initiated in rat brain homogenates by $Fe^{2+}$ and L-ascorbic acid. In consistence with these findings, hesperetin protected primary cultured cortical cells against the oxidative neuronal damage induced by $H_2O_2$ or xanthine and xanthine oxidase. In addition, it was shown to attenuate the excitotoxic neuronal damage induced by excess glutamate in the cortical cultures. When the excitotoxicity was induced by the glutamate receptor subtype-selective ligands, only the N-methyl-D-aspartic acid-induced toxicity was selectively and markedly inhibited by hesperetin. Furthermore, hesperetin protected cultured cells against the $A_{{\beta}(25-35)}-induced$ neuronal damage. Hesperidin, however, exerted minimal or no protective effects on the neuronal damage tested in this study. Taken together, these results demonstrate potent antioxidant and neuroprotective effects of hesperetin, implying its potential role in protecting neurons against various types of insults associated with many neurodegenerative diseases.

• Natural Product Sciences
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• v.15 no.4
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• pp.203-207
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• 2009

A homoisoflavanone, 7,4'-dihydroxyhomoisoflavanone (1) and a flavanone, (2S)-7,4'-dihydroxy-5-methoxyflavanone (2), were isolated from the rhizomes of Anemarrhena asphodeloides, together with 4,4'-dihydroxychalcon (3), 2'-O-methylphlorethin (4), 1,3-bis-di-p-hydroxyphenyl-4-penten-1-one (5), and 2,4'-dihydroxy-4-methoxybenzophenone (6) on the basis of spectroscopic and physicochemical analyses including 1Dand 2D- NMR techniques as well as by comparison of their data with the published values. Compounds 1 - 4 were isolated for the first time from this plant source. Among isolates, compound 2 exhibited moderate inhibitory effect on the differentiation of pre-adipocyte 3T3-L1 cells.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.605-613
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• 2014

We have previously shown that paraquat (PQ)-induced oxidative stress causes dramatic damage in various human cell lines. Naringenin (NG) is an active flavanone, which has been reported to have beneficial bioactivities, including antioxidative, anti-inflammatory, and antitumorigenic activities, with a relatively low toxicity to normal cells. In this study, we intended to assess the cytoprotective effect of NG against PQ-induced toxicity in the human bronchial epithelial BEAS-2B cell line. Co-treatment with NG in PQ-treated BEAS-2B cells can reduce PQ-induced cellular toxicity. NG can also decrease the generation of intracellular ROS caused by PQ treatment. We also observed that treatment with NG in PQ-exposed BEAS-2B cells can significantly induce the expression of antioxidant-related genes, including GPX2, GPX3, GPX5, and GPX7. NG co-treatment can also activate the NRF2 transcription factor and promote its nuclear translocation. In addition, NG co-treatment can induce the expression of NRF2-downstream target genes such as that of heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). A small interfering RNA study revealed that the knockdown of NRF2 can abrogate NG-mediated protection of the cells from PQ-induced cellular toxicity. We propose that NG effectively alleviates PQ-induced cytotoxicity in human bronchial epithelial BEAS-2B cells through the NRF2-regulated antioxidant defense pathway, and NG might be a good therapeutic candidate molecule in oxidative stress-related diseases.

• Nutritional Sciences
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• v.2 no.2
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• pp.71-75
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• 1999

Epidemiologic studies consistently demonstrate an inverse relationship between risk for colon canter and consumption of fruits and vegetables. Wheat bran, flax and soy contain dietary fiber and phytochemicals, such as lignans and isoflavones, that may inhibit colon carcinogenesis. Orange juice contains hesperidin, a flavanone glucoside that protects against colon carcinogenesis. This study determined if feeding orange juice, wheat bran, soy and flaxseed (combined diet) would inhibit azoxymethane (AOM) induced colon cancer. Cancer was initiated in male Fisher 344 rats by injecting 15 mg AOM/kg of weight at 22 and 29 days of age. One week after the second AOM injection, rats (N = 30) in the combined diet group received dry diet containing wheat bran (4%), soy with ethanol soluble phytochemirals(13%) and flaxseed (8%) and orange juice replaced drinking water. The control group remained on the control diet and received distilled water to drink. The rats were killed 28 weeks later, and colon tissues and tumors were removed for histologic analysis. Feeding the combined diet significantly reduced tumor incidence (p < 0.05), however tumor multiplicity was not changed (p > 0.05, 0.9 tumors/rat fed the combined diet vs 1.2 for controls). Also, tumor burden was only marginally reduced in rats fed the combined diet vs control rats (65 vs 210 mg of tumor/rats, respectively). The reduction in tumor incidence was associated with a decreased labeling index and proliferation zone in normal appearing colon mucosa. Therefore, this study shows that phytochemicals in wheat bran, soy, flax and orange juice reduce colon carcinogenesis, presumably by decreasing cell proliferation and enhancing cell differentiation.