|Int J Mol Sci. 2018 Feb 22;19(2). pii: E620. |
|3,5,6,7,8,3',4'-Heptamethoxyflavone, a Citrus Flavonoid, Inhibits Collagenase Activity and Induces Type I Procollagen Synthesis in HDFn Cells.[Pubmed: 29470423]|
|Citrus fruits contain various types of flavonoids with powerful anti-aging and photoprotective effects on the skin, and have thus been attracting attention as potential, efficacious skincare agents. |
METHODS AND RESULTS:
Here, we aimed to investigate the chemical composition of Citrus unshiu and its protective effects on photoaging. We isolated and identified a bioactive compound, 3,5,6,7,8,3',4'-heptamethoxyflavone (3,3',4',5,6,7,8-heptamethoxyflavone ,HMF), from C. unshiu peels using ethanol extraction and hexane fractionation. HMF inhibited collagenase activity and increased type I procollagen content in UV-induced human dermal fibroblast neonatal (HDFn) cells. HMF also suppressed the expression of matrix metalloproteinases 1 (MMP-1) and induced the expression of type I procollagen protein in UV-induced HDFn cells. Additionally, HMF inhibited ultraviolet B (UVB)-induced phosphorylation of the mitogen-activated protein kinases (MAPK) cascade signaling components-ERK, JNK, and c-Jun-which are involved in the induction of MMP-1 expression. Furthermore, HMF affected the TGF-β/Smad signaling pathway, which is involved in the regulation of type I procollagen expression. In particular, HMF induced Smad3 protein expression and suppressed Smad7 protein expression in UV-induced HDFn cells in a dose-dependent manner.
These findings suggest a role for Citrusunshiu in the preparation of skincare products in future.
|J Agric Food Chem. 2008 Oct 22;56(20):9399-403. |
|Anti-inflammatory activity of an orange peel polymethoxylated flavone, 3',4',3,5,6,7,8-heptamethoxyflavone, in the rat carrageenan/paw edema and mouse lipopolysaccharide-challenge assays.[Pubmed: 18816060 ]|
|The anti-inflammatory properties of 3',4',3,5,6,7,8-heptamethoxyflavone (3,3',4',5,6,7,8-heptamethoxyflavone ,HMF), a citrus polymethoxylated flavone, were studied in the bacterial lipopolysaccharide (LPS)-challenge/tumor necrosis factor-alpha (TNFalpha) response in mice and in the carrageenan/paw edema assay in rats. |
METHODS AND RESULTS:
In each of these trials, HMF administered by intraperitoneal (ip) injection exhibited anti-inflammatory activity, whereas HMF administered orally (po) produced no effects. The inhibition observed in the LPS-challenge/TNFalpha assay correlated with the HMF levels in the blood sera of mice dosed (ip) with either 33 or 100 mg/kg body weight. Low levels of HMF (0.035 +/- 0.024 ppm) were detected in the blood sera of mice dosed orally [100 mg of HMF (suspended in vegetable oil)/kg], whereas ip injection led to higher levels (0.517 +/- 0.051 ppm). This may account for the different levels of anti-inflammatory effects observed in mice following ip vs oral HMF administration. HMF metabolites, including a number of mono- and di-demethylated HMF metabolites and their glucuronic acid conjugates, were also detected, but results of these studies suggest that the glucuronidated metabolites of HMF are inactive in these inflammation models.
|Cancer Lett. 2001 Feb 10;163(1):7-9. |
|Cancer chemopreventive activity of 3,5,6,7,8,3',4'-heptamethoxyflavone from the peel of citrus plants.[Pubmed: 11163102]|
METHODS AND RESULTS:
Nobiletin and 3,5,6,7,8,3',4'-heptamethoxyflavone (3,3',4',5,6,7,8-heptamethoxyflavone ,HPT), isolated from the peel of Citrus plants, were examined for the anti-tumor-initiating activity on two-stage carcinogenesis of mouse skin tumors induced by a nitric oxide donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexenamide, as an initiator and 12-O-tetradecanoylphorbol-13-acetate as a promoter.
HPT exhibited the remarkable anti-tumor-initiating effect on mouse skin and it suggested the possibility of HPT being a chemopreventive agent against nitric oxide (NO) carcinogenesis.
|J Food Biochem . 2019 Jun;43(6):e12813. |
|Anti-neuroinflammatory activities of extract and polymethoxyflavonoids from immature fruit peels of Citrus 'Hebesu'[Pubmed: 31353615]|
Chronic neuroinflammation is reported to be associated in the progression of many neurodegenerative diseases and there is an increasing interest for the natural products as neuroprotective and anti-neuroinflammatory agents. In present research, we evaluated the potential inhibitory effects of extract, fractions, and isolated compounds from Citrus 'Hebesu' on lipopolysaccharide (LPS)-induced inflammatory responses using BV-2 murine microglial cells. The dried methanol extract (CH) was suspended in water and partitioned with hexane and ethyl acetate to give hexane soluble (CHH), ethyl acetate soluble (CHE), and water soluble (CHW) fractions. The extract (CH) and fractions CHH and CHE inhibited the expression of mRNA encoding pro-inflammatory cytokine interleukin (IL)-1β. CHE and CHH were further purified by various column chromatographic methods to obtain hesperidin (1), tangeretin (2), 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (3), 3,5,6,7,8,3',4'-heptamethoxyflavone (4), nobiletin (5), 3,4,5-trimethoxy-trans-cinnamic alcohol (6), and meranzin hydrate (7). Among them, three polymethoxyflavonoids, 3, 4, and 5 significantly inhibited the expression of IL-1β mRNA. PRACTICAL APPLICATIONS: Citrus 'Hebesu' is a local cultivar in Hyuga City, Miyazaki prefecture, Japan and its immature fruits are consumed with different food recipes. Till now, there is no detailed study on the chemical constituents and anti-neuroinflammatory activity of this cultivar. In this study, seven compounds were isolated from the peels of immature fruits. Methanol extract, hexane, and ethyl acetate fractions and three polymethoxyflavonoids showed a significant inhibitory activity against expression of IL-1β mRNA. Consumption of peels of Citrus 'Hebesu' might play important role in the prevention and treatment of neurodegenerative diseases, however, detailed mechanism based in vivo studies are necessary in future for providing more scientific evidences.
Keywords: BV-2 cells; Citrus ‘Hebesu’; neuroinflammation; nobiletin; polymethoxyflavonoids.|