• Archives of Pharmacal Research
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• v.17 no.2
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• pp.71-75
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• 1994

The antimutagenic effects of 27 kinds of plant flavonoids on the mutagenicity of aflatoxin $B_1(AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MANG) in Salmonella typhimurium TA 100 were investigated. In the mixed applications of $AFB_1\;(1\;\mu{g/plate)}$ with the flavonoids $(300\;\mu{g/plate)}$ in the presence of a mammalian metabolic activation system (S9 mix), chrysin, apigenin, luteolin and its glucoside, kaempferol, fisetin, morin, naringenin, hesperetin, persicogenin, (+)-catechin and (-)epicatechin showed the antimutagenic effect against $AFB_1$ with more than 70% inhibition rate. A little or no antimutagenicities except flavone against MNNG $(0.5\;\mu{g/plate)}$ were observed. For the antimutagencity of the flavonoids on $AFB_1$, the flavonoid structure that contains the free 5, 7-hydroxyl gorup seemed to be essential. However, saturation of the 2, 3-double bond of elimination of the 4-keto group did not affect the activity.

• Food Science and Preservation
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• v.4 no.2
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• pp.181-187
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• 1997

New HPLC method was developed for determination of some flavonoids such as naringin, hesperidin, neohesperidin, rutin, quercitrin, naringenin, hesperetin and apigenin and their contents in citrus juice and citrus peel from citrus varieties Brown in Cheju. Detection was at 280nm and reverse phase ${\mu}$-Bondapak C-18 column was used. Water/methanol/acetic acid as the mobile phase was better than water/acetonitrile/acetic acid. Flavonoids were more stable in 20% n,n-dimethylformamide in methanol(20% DMF) than methanol and pH 12 adjusted by 1N-sodium hydroxide solution. Standard flavonoid solutions were injected three times consecutively and the reproduciability was 0.236 to 3.550%, Correlation coefficient of the calibration curve was 0.9946 to 0.9999. The exiraction efficiency of hesperidin from citrus peel was evaluated with different extraction method such as reflux, ultra-sonicating method, using three solvents (aqueous solutions with pH12 adjusted by 1N-sodium hydroxide, methanol and 20% DMF), respectively. The reflux for 4 hour in 20% DMF was the most efficient of the tested methods and solvents, and recovery percentage were 78.0∼130.0%. Flavonoids were determined in citrus juice. Naringin was 68.2mg/100$m\ell$ in Natsudaidai, Hesperidin were 85.6mg/100$m\ell$ in Sankyool and Neohesperidin was 25.3mg/100$m\ell$ in Dangyooja. Flavonoids were determined in citrus peel. Naringin was 110mg/g in Dangyooja, Hesperidin was 242mg/g in Hungjin and Neohesperidin was 87.9mg/g in Dangyooja.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.1-4
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• 2002

Eleven flavonoids, including rutin, naringin, hesperidin, neohesperidin, quercetin, naringenin, kaempferol, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone and tangeretin in the peel of late maturing citrus fruit species of Mucott (smith tangerine), Singamha (C. natsudidai), Sambogam (C. sulcata), Hongpalsak (C. hassaku), Seminol (Dancy tangerine) and Jawdung (C. aurantium) harvested during from August to December were analyzed with HPLC. The mobile phase consisted of water and acetonitrile with 0.5% acetic acid. Wavelength in UV detector was determined at 254 nm. Naringin and neohesperidin content in the peel of Jawdung harvested at the early stage of maturation were 34.02 mg/g and 13.68 mg/g, respectively, and it was highest among the tested citrus fruits. Hesperidin content in the peel of Mucott harvested at the earthy stage of maturation was 12.48 mg/g. Rutin content of Sambogam harvested at the early stage of maturation was 5.13 mg/g. Quercetin, naringein, kaempferol, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone flavonoids were in trace. Flavonoid contents of Singamha, Sambogam and Jawdung were high in the peel of fruits at the early stage of maturation, after which time they decreased rapidly.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.224-228
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• 2005

Protective effects of various natural flavonoids on carbon tetrachloride $(CCl_4)-induced$ hepatotoxicity were investigated in primary cultured rat hepatocytes. Some of these flavonoids decreased the ALT and LDH releases induced by $CCl_4$ in A dose-dependent manner. Neohesperidin, hesperetin, baicalin, baicalein and quercetin inhibited $CCl_4-induced$ alanine aminotransferase (ALT) release. In addition, quercetin, quercitrin, neohesperidin, baicalin, baicalein and naringin reduced $CCl_4$ induced lactate dehydrogenase (LDH) leakage. Among these flavonoids, quercitrin, quercetin, baicalin and baicalein possessed potent protective effects and were selected for the further investigation on lipid peroxidation. These four flavonoids inhibited dose dependently $CCl_4-induced$ lipid peroxidation. Especially, the protective effects of quercetin and baicalein were similar to silybin as a well-known hepatoprotective agent. These results suggest that these four flavonoids have significant cytoprotective effects and possibility of therapeutic effect on chemical-induced liver diseases.

• Natural Product Sciences
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• v.27 no.3
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• pp.151-160
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• 2021

Under some pathological conditions such as osteoarthritis, matrix metalloproteinases (MMPs) including MMP-13 have an important role in degrading cartilage materials. When the regulatory effects of some herbal extracts on MMP-13 expression were examined to evaluate the cartilage-protective potential, the ethanol extract of the radix of Viscum album was found to strongly downregulate MMP-13 induction in IL-1β-treated chondrocytes, SW1353 cells. Based on this finding, activity-guided separation was carried out, which yielded five constituents identified as 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)heptane (1), hesperetin-7-glucoside (2), syringin (3), homoflavoyadorinin B (4), and 4,4'-dihydroxy-3,6'-dimethoxychalcone-2'-glucoside (5). Of these, 1 and 5 significantly inhibited MMP-13 expression in SW1353 cells, with 5 being the most potent. Compound 5, a chalcone derivative, showed the downregulation of MMP-13 at 20 - 100 μM. The mechanism study revealed that 5 exerted MMP-13 down-regulatory action, at least in part, by interrupting the signal transducer and activator of transcription 1 (STAT1) activation pathway. Furthermore, this compound protected against cartilage degradation in an IL-1-treated rabbit cartilage explant culture. All these findings demonstrated for the first time that Viscum album and its constituents, especially chalcone derivative (5), possessed cartilage-protective activity. These natural products may have the potential for alleviating cartilage degradation.

• Natural Product Sciences
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• v.25 no.1
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• pp.76-80
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• 2019

Bioactivity-guided fractionation of MeOH extract of the dried fruits of Amomum tsao-ko led to isolation of nine compounds (1 - 9). Their structures were elucidated by spectroscopic methods including extensive 1D and 2D-NMR, as alpinetin (1), naringenin-5-O-methyl ether (2), naringenin (3), hesperetin (4), 2',4',6'-trihydroxy-4-methoxy chalcone (5), tsaokoin (6), boesenbergin B (7), 4-hydroxyboesenbergin B (8), and tsaokoarylone (9). Of these, compound 8 was isolated from a natural source for the first time, which was previously reported as a synthetic product. The isolated compounds (1 - 9) were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Among them, three chalcone derivatives (compounds 5, 7, and 8) and a diarylheptanoid (compound 9) exhibited significant inhibitory activity on the NO production with $IC_{50}$ values ranging from 10.9 to $22.5{\mu}M$.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.427-436
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• 2012

Targeted therapy has been a very promising strategy of drug development research. Many molecular mechanims of diseases have been known to be regulated by abundance of proteins, such as receptors and hormones. Chemoprevention for treatment and prevention of diseases are continuously developed. Pre-clinical and clinical studies in chemoprevention field yielded many valuable data in preventing the onset of disease and suppressing the progress of their growth, making chemoprevention a challenging and a very rational strategy in future researches. Natural products being rich of flavonoids are those fruits belong to the genus citrus. Ethanolic extract of Citrus reticulata and Citrus aurantiifolia peels showed anticarcinogenic, antiproliferative, co-chemotherapeutic and estrogenic effects. Several examples of citrus flavonoids that are potential as chemotherapeutic agents are tangeretin, nobiletin, hesperetin, hesperidin, naringenin, and naringin. Those flavonoids have been shown to possess inhibition activity on certain cancer cells' growth through various mechanisms. Moreover, citrus flavonoids also perform promising effect in combination with several chemotherapeutic agents against the growth of cancer cells. Some mechanisms involved in those activities are through cell cycle modulation, antiangiogenic effect, and apoptosis induction.Previous studies showed that tangeretin suppressed the growth of T47D breast cancer cells by inhibiting ERK phosphorylation. While in combination with tamoxifen, doxorubicin, and 5-FU, respectively, it was proven to be synergist on several cancer cells. Hesperidin and naringenin increased cytotoxicitity of doxorubicin on MCF-7 cells and HeLa cells. Besides, citrus flavonoids also performed estrogenic effect in vivo. One example is hesperidin having the ability to decrease the concentration of serum and hepatic lipid and reduce osteoporosis of ovariectomized rats. Those studies showed the great potential of citrus fruits as natural product to be developed as not only the source of co-chemotherapeutic agents, but also phyto-estrogens. Therefore, further study needs to be conducted to explore the potential of citrus fruits in overcoming cancer.

• Mycobiology
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• v.39 no.1
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• pp.12-19
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• 2011

Cellular damage caused by reactive oxygen species has been implicated in several diseases, thus establishing a significant role for antioxidants in maintaining human health. Acetone, methanol, and hot water extracts of Pleurotus citrinopileatus were evaluated for their antioxidant activities against ${\beta}$-carotene-linoleic acid and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power, ferrous ion-chelating abilities, and xanthine oxidase inhibitory activities. In addition, the tyrosinase inhibitory effects and phenolic compound contents of the extracts were also analyzed. Methanol and acetone extracts of P. citrinopileatus showed stronger inhibition of ${\beta}$-carotene-linoleic acid compared to the hot water extract. Methanol extract (8 mg/mL) showed a significantly high reducing power of 2.92 compared to the other extracts. The hot water extract was more effective than the acetone and methanole extracts for scavenging DPPH radicals. The strongest chelating effect (92.72%) was obtained with 1.0 mg/mL of acetone extract. High performance liquid chromatography analysis detected eight phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin, and biochanin-A, in an acetonitrile and hydrochloric acid (5 : 1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetone, methanol, and hot water extracts increased with increasing concentration. This study suggests that fruiting bodies of P. citrinopileatus can potentially be used as a readily accessible source of natural antioxidants.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1109-1114
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• 2008

To understand the role of intestinal microflora in the biological effect of functional herbs, which have been used in Korea, Japan, and China as traditional medicines, and suggest new bioactive compounds transformed from herbal constituents, the metabolic activities of the functional herb components (ginsenoside Rb1, crocin, amygdalin, geniposide, puerarin, ginsenoside Re, poncirin, hesperidin, glycyrrhizin, and baicalin) toward their bioactive compounds (compound K, crocetin, benzaldehyde, genipin, daidzein, ginsenoside Rh1, ponciretin, hesperetin, 18b-glycyrrhetic acid, and baicalein) were measured in fecal specimens. The metabolic activities of these components were $882.7{\pm}814.5$, $3,938.1{\pm}2,700.8$, $2,375.5{\pm}913.7$, $1,179.4{\pm}795.7$, $24.6{\pm}10.5$, $11.4{\pm}10.8$, $578.8{\pm}206.1$, $1,150.0{\pm}266.1$, $47.3{\pm}58.6$, and $12,253.0{\pm}6,527.6\;{\mu}mol/h/g$, respectively. No differences were found in the metabolic activities of the tested components between males and females, although these metabolic activities between individuals are extensively different. The metabolites of functional herb components showed more potent cytotoxicity against tumor cells than nonmetabolites. These findings suggest that intestinal microflora may activate the pharmacological effect of herbal food and medicines and must be the biocatalytic converter for the transformation of herbal components to bioactive compounds.

• Mycobiology
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• v.38 no.4
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• pp.295-301
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• 2010

We evaluated the antioxidant activity and tyrosinase inhibitory effects of Pleurotus ostreatus fruiting bodies extracted with acetone, methanol, and hot water. The antioxidant activities were tested against $\beta$-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, and ferrous chelating ability. Furthermore, phenolic acid and flavonoid contents were also analyzed. The methanol extract showed the strongest $\beta$-carotene-linoleic acid inhibition as compared to the other exracts. The acetone extract (8 mg/mL) showed a significantly high reducing power of 1.54 than the other extracts. The acetone extract was more effective than other extracts for scavenging on 1,1-diphenyl-2-picrylhydrazyl radicals. The strongest chelating effect (85.66%) was obtained from the acetone extract at 1.0 mg/mL. The antioxidant activities of the extracts from the P. ostreatus fruiting bodies increased with increasing concentration. A high performance liquid chromatography analysis detected seven phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, naringenin, hesperetin, formononetin, and biochanin-A in an acetonitrile and 0.1 N hydrochloric acid (5 : 1) solvent extract. The total phenolic compound concentration was $188{\mu}g$/g. Tyrosinase inhibition of the acetone, methanol, and hot water P. ostreatus extracts increased with increasing concentration. The results revealed that the methanol extract had good tyrosinase inhibitory ability, whereas the acetone and hot water extracts showed moderate activity at the concentrations tested. The results suggested that P. ostreatus may have potential as a natural antioxidant.