• Journal of the Korean Chemical Society
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• v.65 no.5
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• pp.327-332
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• 2021

Shiranuhi is a fruit of Citrus species widely cultivated in Jeju Island, Korea. From an extract of Shiranuhi tree branches were identified five polymethoxyflavones possessing anti-inflammatory effects; nobiletin (1), sinensetin (2), tetramethylscutellarein (3), 6-hydroxy-5,7,3',4'-tetramethoxyflavone (4) and 5-desmethylsinensetin (5). Evaluation of the activities was conducted by monitoring the production of nitric oxide (NO), prostaglandin E₂ and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) as well as the levels of iNOS and COX-2 protein expression in LPS-induced RAW264.7 cells. Among the isolates, the compound 4 exhibited the most significant NO inhibition, and suppressed the levels of iNOS and related cytokines. Therefore, it was suggested that the extract and constituents from Shiranuhi tree branches could be useful as anti-inflammatory ingredient.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.211-218
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• 2014

Polymethoxyflavones (PMFs) are a group of polymethoxylated bioactive flavones with diverse biological activities, including anticancer, anti-inflammatory, antibacterial, and antiviral activities. PMFs are found from various plants such as orange, tangerine, and krachaidum. To establish the simple quantitative analytical methods for PMFs, chromatographic analysis was applied to the selected krachaidum foods because krachaidum contains diverse PMFs compared to other PMF-containing foods. Krachaidum is the rhizome of Kaempferia parviflora, and many commercial krachaidum products, such as tea, juice and wine, are commercially available and consumed as health functional foods in Asian countries. Apart from the claimed health promoting benefits, reliable quality assurance and legal guideline for the registration of these products are not available yet. Twelve PMFs were analyzed from the commercial krachaidum foods by GC-FID and HPLC-DAD. No single chromatographic method could not analyze 12 PMFs simultaneously. HPLC-DAD method was found more sensitive to detect PMFs. Based on our analysis data, we proposed 5,7-dimethoxyflaone and 5,7,4'-trimethoxyflavone as index components for the food products.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6369-6374
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• 2012

Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an $IC_{50}{\sim}28.8{\mu}M$. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.113-123
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• 2018

The application of 112 samples of Citrus fruit peel, which is commonly cultivated in Korea as crude drug, has been limited due to the absence of criteria concerning chemical constituents and application of itself. In the context, this study is on the analysis of 11 flavonoid compounds. As a result, the flavonoid pattern could be classified into 5 groups. Furthermore, by utilizing this HPLC data, this study could provide a basis for fruit peel applications of not only Citrus unshiu, but also its cultivars, hybrids and some of Citrus plants which has been cultivated in Jeju Island for a long time. Moondan could be used for the same purposes as Chinese Huajuhong, and Poncirus trifoliata of Korean Jisil origin are effective enough, in terms of ingredients and function, compared with C. aurantium. Based on the content and composition of the PMF region in this study, C. unshiu and C. reticulata, as Tanaka System shows, should be considered as different hortcultural speicies. Also, Jikak, which is known as 'sour orange' until now, is confirmed as Chosen-daidai, C. tenuissima, that was reported by Tanaka in 1970, and this C. tenuissima could be used for the same purposes as sour orange.

• Journal of Nutrition and Health
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• v.53 no.1
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• pp.1-12
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• 2020

Purpose: Diabetic nephropathy is one of the most important diabetic complications prompted by chronic hyperglycemia, characterized by glomerulosclerosis, tubular fibrosis, and it eventually causes kidney failure. Nobiletin is a polymethoxyflavone present in tangerine and other citrus peels, and has anti-cancer and anti-inflammatory effects. This study investigated the effects of nobiletin on glomerular fibrosis through inhibition of the transforming growth factor (TGF)-β1-Src-caveolin-1 pathway. Methods: Human renal mesangial cells (HRMC) were incubated in media containing 33 mM glucose with or without 1-20 uM nobiletin for 3 day. The cellular expression levels of fibrogenic collagen IV, fibronectin, connective tissue growth factor (CTGF), TGF-β1, Src and caveolin-1 were all examined. In addition, TGF-β1, Src and caveolin-1 proteins were screened to reveal the relationship among TGF-β1-Src-caveolin-1 signaling in glomerular fibrosis. Results: High glucose promoted the production of collagen IV, fibronectin and CTGF in HRMC, which was inhibited in a dose dependent manner by 1-20 uM nobiletin. The Western blot data showed that high glucose elevated the expression of TGF-β1, Src, caveolin-1 and Rho GTPase. When nobiletin was treated to the HRMC exposed to high glucose, the expression of TGF-β1-Src-caveolin-1 was dampened. Finally, TGF-β1-Src-caveolin-1 signaling pathway was activated in high glucose-exposed HRMC, and such activation was encumbered by nobiletin. Conclusion: These result demonstrated that nobiletin blunted high glucose-induced extracellular matrix accumulation via inhibition of the TGF-β1-Src-caveolin-1 related intracellular signaling pathway. Nobiletin may be a potent renoprotective agent to counteract diabetes-associated glomerular fibrosis that leads to kidney failure.

• Food Science and Preservation
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• v.23 no.7
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• pp.1012-1017
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• 2016

This study was conducted to investigate total flavonoid content, flavonoid composition, and free radical scavenging effects of by-products from five orange cultivars during the period September 2015 to February 2016. Total flavonoid content was highest in peel extracts from immature fruit harvested in September. Total flavonoid contents of all cultivars mostly decreased while ripening. Among the five cultivars, total flavonoid content was highest in Hamlin sweet orange (21.66 mg/g), followed by Sanguinello blood orange (20.39 mg/g), Shamouti orange (18.49 mg/g), Tarocco blood orange (18.46 mg/g), and Olinda Valencia orange (17.07 mg/g). With regard to flavonoid composition, all cultivar materials had high levels of narirutin and hesperidin, but naringin and neohesperidin were not detected in any of the materials. Nobiletin, as polymethoxyflavone, was detected within a$23{\sim}40{\mu}g/mL$ range in the immature fruit of all cultivars. Among all cultivars, antioxidant activities were higher in peel extracts than in pulp extracts. DPPH radical scavenging activities of peel extracts ranged from 40% to 58% while the ABTS radical scavenging activity range was 90~94%. The results indicate that orange, by-products, especially peel of immature orange fruit, could have application as natural materials with antioxidative effects.