Inhibitory Effects of Luteolin 7-Methyl Ether Isolated from Wikstroemia ganpi on Tnf-A/Ifn-Γ Mixture-Induced Inflammation in Human Keratinocyte.

Plants of the genus Wikstroemia are traditionally used in China to treat various inflammatory diseases. The purpose of this study was to isolate the components of Wikstroemia ganpi (Siebold & Zucc.) Maxim., to evaluate their anti-atopic activities and to identify candidates with anti-atopic therapeutics. A total of 24 compounds were isolated by bioassay-guided separation, including one novel compound, which was tilianin 5-methyl ether. The anti-atopic activities of the isolated compounds were determined using TNF-α-treated RBL-2H3 cells and HaCaT cells. The mRNA expressions of IL-4, IL-6, GM-CSF, G-CSF and TRPV1 were reduced by luteolin 7-methyl ether. The study shows that the luteolin 7-methyl ether isolated from W. ganpi is a potential therapeutic agent for the treatment of atopic dermatitis.

Haplopine Ameliorates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions in Mice and TNF-α/IFN-γ-Induced Inflammation in Human Keratinocyte.

This study aimed to investigate the anti-inflammatory, antioxidant, and anti-atopic dermatitis (AD) effects of haplopine, which is one of the active components in D. dasycarpus. Haplopine (12.5 and 25 µM) inhibited the mRNA expressions of inflammatory cytokines IL-6, TSLP, GM-CSF, and G-CSF and the protein expressions of IL-6 and GM-CSF in TNF-α/INF-γ-stimulated HaCaT cells. In H2O2-induced Jukat T cells, haplopine (25 and 50 µM) suppressed the productions of proinflammatory cytokines (IL-4, IL-13, and COX-2) and increased the mRNA and protein expressions of oxidative stress defense enzymes (SOD, CAT, and HO-1) in a concentration-dependent manner. In vivo, haplopine significantly attenuated the development of AD symptoms in 2,4-dinitrochlorobenzene (DNCB)-stimulated Balb/c mice, as evidenced by reduced clinical dermatitis scores, skin thickness measurements, mast cell infiltration, and serum IgE concentrations. These findings demonstrate that haplopine should be considered a novel anti-atopic agent with the potential to treat AD.

Wikstroemiaganpi Extract Improved Atopic Dermatitis-Like Skin Lesions via Suppression of Interleukin-4 in 2,4-Dinitrochlorobenzene-Induced SKH-1 Hairless Mice.

Plants of the genus Wikstroemia are used in Chinese traditional medicine to treat inflammatory diseases, such as arthritis, bronchitis, and pneumonia. The present study was designed to determine whether Wikstroemia ganpi (Siebold and Zucc.) Maxim. offers a potential means of treating 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) in mice. Symptoms such as redness, edema, and keratinization in AD mice induced by DNCB were alleviated by the co-application of an ethanolic extract of W. ganpi for 2 weeks. The severity of skin barrier function damage was evaluated by measuring TEWL (transepidermal water loss). TEWLs of DNCB sensitized mouse dorsal skin were reduced by the application of a W. ganpi ethanolic extract, and skin hydration was increased. In addition, the infiltration of inflammatory cells into the dermis was significantly reduced, as were blood levels of IgE and IL-4, which play an important role in the expression of AD. The results of this experiment suggest that W. ganpi is a potential therapeutic agent for AD.

Quercitrin, the Main Compound in Wikstroemia indica, Mitigates Skin Lesions in a Mouse Model of 2,4-Dinitrochlorobenzene-Induced Contact Hypersensitivity.

Hapten-induced contact hypersensitivity (CHS) is widely utilized to induce immune activation in animal models of allergic contact dermatitis. Our previous findings suggested that the 95% EtOH extract of Wikstroemia indica (L.) C. A. Mey. has antiallergic and anti-inflammatory effects in DNCB-treated CHS SKH-1 hairless mice. The aim of this study was to evaluate the protective effects of compounds isolated from the EtOAc fraction of W. indica in RBL-2H3 cells and 2,4-dinitrochlorobenzene- (DNCB-) induced CHS mice. Of eight compounds in W. indica, that is, umbelliferone, daphnoretin, wikstrocoumarin, (+)-syringaresinol, tricin, (+)-lariciresinol, erythro-guaiacylglycerol-ß-coniferyl ether, and quercitrin, quercitrin exhibited the most antiallergic activity against antigen-induced ß-hexosaminidase release and IL-4 mRNA expression, which are markers of degranulation in RBL-2H3 cells. After a 7-sensitizing period, 14 days of DNCB treatment with or without topical pimecrolimus (1%) or quercitrin (0.5%) treatment, quercitrin was found to suppress DNCB-induced increases in serum IL-4 and IgE concentrations and transepidermal water loss. These results indicate that quercitrin has therapeutic potential for treatment of allergies and allergy-related contact dermatitis.

The Effects of Aronia melanocarpa Extract on Testosterone-Induced Benign Prostatic Hyperplasia in Rats, and Quantitative Analysis of Major Constituents Depending on Extract Conditions.

This study aimed to investigate the beneficial effects of A. melanocarpa on testosterone propionate (TP)-induced benign prostatic hyperplasia (BPH) in Wistar rats. Moreover, the bioactive constituents in the extract were determined using LC/MS and HPLC analyses. The dried fruits of A. melanocarpa were extracted using accelerated solvent extraction (ASE) under different extract conditions (temperature, 30 C or 100 C; extract solvent, 60% or 100% ethanol) to yield four extracts (T1~T4). Of the four A. melanocarpa extracts, T1 extracted under the condition of 100% ethanol/low temperature (30 C) exhibited the greatest inhibitory activity on TP-induced prostatic hyperplasia in rats. The administration of T1 (100 mg/kg body weight, p.o.) for six weeks attenuated TP-induced prostate enlargement and reduced the levels of dihydrotestosterone (DHT) and 5α-reductase in both serum and prostate tissue. The suppression of PCNA mRNA expression in prostate tissue was remarkable in T1-treated rats. In LC/MS analysis, the levels of main anthocyanins and phenolics were significantly higher in T1 than in the other extracts. Furthermore, the quantitative study showed that the contents of cyanidin-3-glucose and cyanidin-3-xylose in T1 exhibited 1.27~1.67 and 1.10~1.26 folds higher compared to those in the other extracts. These findings demonstrated that A. melanocarpa extract containing anthocyanins as bioactive constituents attenuated the development of testosterone-induced prostatic hyperplasia, and suggested that this extract has therapeutic potential to treat prostate enlargement and BPH.

Suppression of DNCB-Induced Atopic Skin Lesions in Mice by Wikstroemia indica Extract.

Wikstroemia indica (L.) C.A. Mey. is used in traditional Chinese medicine to treat inflammatory diseases such as arthritis and bronchitis. In this study, we aimed to investigate the effects of an ethanolic extract of W. indica on cutaneous inflammation in mice with 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD). Dermal administration of W. indica ethanolic extract to DNCB-sensitized hairless mice with dermatitis, for two weeks, reduced erythema, scaling, and edema. Skin hydration was improved and transepidermal water loss was reduced at a W. indica concentration of 1%. Furthermore, W. indica also significantly reduced serum IgE and IL-4 concentrations in our mouse model. These results suggest that W. indica has potential as a topical treatment for AD and as an adjunctive agent to control AD.

Chamaejasmine Isolated from Wikstroemia dolichantha Diels Suppresses 2,4-Dinitrofluoro-benzene-Induced Atopic Dermatitis in SKH-1 Hairless Mice.

Plants of the genus Wikstroemia have long been used as traditional medicines to treat diseases like pneumonia, rheumatism, and bronchitis. This study was designed to determine the effect of chamaejasmine, a biflavonoid present in W. dolichantha, on atopic dermatitis (AD)-like skin lesions in a 2,4-dinitrochlorobenzene (DNCB)-induced murine model of AD. Initially, we examined the anti-allergic activities of ten flavonoids from W. dolichantha by measuring ß-hexosaminidase release from RBL-2H3 cells. Subsequently, an SKH-1 hairless mouse model of AD was developed based on the topical application of DNCB. Chamaejasmine (0.5%) or pimecrolimus (1%, positive control) were applied to dorsal skins of DNCB-sensitized AD mice for two weeks. Serum IL-4 and IgE levels were determined using enzyme-linked immunosorbent assay kits and transepidermal water loss (TEWL) and skin hydration were measured using a Tewameter TM210 and a SKIN-O-MAT, respectively. Of the ten flavonoids isolated from W. dolichantha, chamaejasmine most potently inhibited DNP-specific IgE-induced degranulation in RBL-2H3 cells. Topical administration of chamaejasmine attenuated the clinical symptoms of DNCB-induced dermatitis (i.e., itching, dryness, erythema, and edema). Histological analyses demonstrated that dermal thickness and mast cell infiltration in dermis were significantly reduced by chamaejasmine. In addition, 0.5% chamaejasmine inhibited DNCB-induced increases in total IL-4 and IgE levels in serum, improved skin barrier function, and increased epidermis moisture. Our findings suggest chamaejasmine might be an effective therapeutic agent for the treatment of atopic diseases.

Effect of Topically Applied Wikstroemia dolichantha Diels on the Development of Atopic Dermatitis-Like Skin Symptoms in Mice.

Plants of the genus Wikstroemia are traditionally used to treat inflammatory diseases like bronchitis and rheumatoid arthritis. In the present study, the anti-atopic effects of an EtOH extract of Wikstroemia dolichantha (WDE) on oxazolone- and DNCB (2,4-dinitrochlorobenzene)-induced dermatitis in mice were investigated. Both ears of BALB/c mice were exposed to oxazolone, and dorsal skins of SKH-1 hairless mice were sensitized with DNCB to induce acute eczematous atopic skin lesions. 1% WDE was applied daily to oxazolone- and DNCB-induced AD mice for two or three weeks, respectively. Total IL-4 and IgE concentrations in serum, transepidermal water loss (TEWL) and skin hydration were assessed. High-performance liquid chromatography/mass spectrometry (HPLC/MS) was used to determine the composition of WDE. Dermal application of 1% WDE grossly and histopathologically improved oxazolone- and DNCB-induced AD skin symptoms. Epidermal thickness and mast cell infiltration were significantly lower in animals treated with WDE than in vehicle controls. Furthermore, in addition to reducing DNCB-induced increases in serum IL-4 (interleukin 4) and IgE (immunoglobulin E) levels, WDE also decreased TEWL and increased skin hydration (indicative of improved skin barrier function). The four flavonoids taxifolin, aromadendrin, padmatin and chamaejasmine were tentatively identified in WDE by HPLC-DAD/QTOF-MS. The above results show WDE protected against oxazolone- and DNCB-induced AD in mice by down-regulating the TH2-associated cytokine IL-4 and improving skin barrier function and suggest WDE might be useful for the management of atopic dermatitis.

Stellera chamaejasme and Its Main Compound Luteolin 7-O-Glucoside Alleviates Skin Lesions in Oxazolone- and 2,4-Dinitrochlorobenzene-Stimulated Murine Models of Atopic Dermatitis.

Stellera chamaejasme, also known as "Langdu", has been traditionally used for the management of skin-related diseases such as psoriasis and skin ulcers. The aim of this study was to determine whether S. chamaejasme and its major component, luteolin 7-O-glucoside, have a preventive effect on the development of atopic dermatitis in oxazolone-treated BALB/c mice and 2,4-dinitrochlorobenzene-treated hairless mice. The epicutaneous applications of oxazolone and 2,4-dinitrochlorobenzene evoke an experimental murine atopic dermatitis-like reaction in BALB/c mouse ears and SKH-1 hairless mice. Atopic skin symptoms, including erythema (redness), pruritus (itching), exudation (weeping), excoriation (peeling), and lichenification (skin thickening), responded to treatment with S. chamaejasme aerial parts EtOH extract for 2 or 3 weeks. Histopathological examination revealed S. chamaejasme aerial parts EtOH extract significantly reduced inflammatory cell infiltration when applied to atopic dermatitis mice. In addition, luteolin 7-O-glucoside, the major active compound of the S. chamaejasme aerial parts EtOH extract, decreased serum IgE and IL-4 levels and transepidermal water loss and increased skin hydration, therefore exhibiting strong anti-atopic dermatitis activity in 2,4-dinitrochlorobenzene-induced atopic dermatitis mice. In this study, we confirmed antipruritic and antidermatitic effects of S. chamaejasme extract and its main component luteolin 7-O-glucoside in atopic dermatitis murine models. The study shows S. chamaejasme aerial parts EtOH extract and luteolin 7-O-glucoside are most likely to be potential drug candidates for atopic dermatitis treatment.

Isolation of maltol derivatives from Stellera chamaejasme and the anti-atopic properties of maltol on skin lesions in DNCB-stimulated mice.

The aim of this study was to isolate maltol derivatives from S. chamaejasme and to investigate the anti-atopic dermatitis (anti-AD) effect of maltol in a 2,4-dinitrochlorobenzene (DNCB)-sensitized mouse model of AD. A novel compound, maltol 3-O-(4'-O-cis-p-coumaroyl)-ß-d-glucoside (named isosoyamaloside I), and two known maltol derivatives (maltol and soyamaloside I) were isolated from S. chamaejasme using chromatographic methods. Dermal application of maltol to DNCB-sensitized AD mice reduced erythema, pruritus, and lichenification scores. Histopathological examinations revealed significant decline in mast cell infiltration in maltol-treated AD mice. In addition, maltol accelerated skin barrier recovery by reducing TEWL and skin pH and increasing skin hydration. Maltol was also found to suppress atopy-induced IL-4 and IgE elevations in serum, which are known to be essential for the development of atopy. The results of this study show that maltol is a potential therapeutic candidate for the treatment of AD-related skin diseases.

Antiobesity Effect of Fermented Chokeberry Extract in High-Fat Diet-Induced Obese Mice.

Black-fruited chokeberries (Aronia melanocarpa), growing mainly in the Central and Eastern European countries, have health benefits due to the high concentrations of polyphenolic compounds. However, a strong bitter taste of chokeberries limits its usage as functional food. We hypothesized that the fermented A. melanocarpa with a reduced bitter taste would improve insulin sensitivity and/or ameliorate weight gain induced by high-fat diet (HFD) in male C57BL/6J mice. The mice were administered with HFD together with the 100 mg/kg of natural A. melanocarpa (T1) or the fermented A. melanocarpa (T2) for 8 weeks. The treatment with T2 (100 mg/kg body weight, p.o.) markedly attenuated the weight gain and the increase in serum triglyceride level induced by HFD. The T2-treated group had better glucose tolerance and higher insulin sensitivity as measured by oral glucose tolerance test and intraperitoneal insulin tolerance test in comparison to the T1-treated group. Phytochemical analysis revealed that the main constituents of T2 were cyanidin-3-xyloside and 1-(3',4'-dihydroxycinnamoyl)cyclopenta-2,3-diol, and the content of cyanidin glycosides (3-glucoside, 3-xyloside) was significantly reduced during the fermentation process. From the above results, we postulated that antiobesity effect of black chokeberry was not closely correlated with the cyanidin content. Fermented chokeberry might be a viable dietary supplement rich in bioactive compounds useful in preventing obesity.

Chokeberry Extract and Its Active Polyphenols Suppress Adipogenesis in 3T3-L1 Adipocytes and Modulates Fat Accumulation and Insulin Resistance in Diet-Induced Obese Mice.

Berries of Aronia melanocarpa (chokeberry) are known to be a rich source of biologically active polyphenols. In the present study, the effects of seven anti-adipogenic polyphenolic phytochemicals isolated from A. melanocarpa methanol extract on adipogenic transcription factors were investigated. Amygdalin and prunasin were found to inhibit 3T3-L1 adipocyte differentiation by suppressing the expressions of PPARγ (peroxisome proliferator-activated receptor γ), C/EBPα (CCAAT/enhancer binding protein α), SREBP1c (sterol regulatory element binding protein 1c), FAS (fatty acid synthase), and aP2 (adipocyte fatty-acid⁻binding protein). A. melanocarpa extract-treated (100 or 200 mg/kg/day on body weight) high fat diet (HFD)-induced obese mice showed significant decreases in body weight, serum triglyceride (TG), and low-density lipoprotein cholesterol (LDLC) levels and improved insulin sensitivity as compared with HFD controls. This research shows A. melanocarpa extract is potentially beneficial for the suppression of HFD-induced obesity.

Anti-Atopic Properties of Gracillin Isolated from Dioscorea quinqueloba on 2,4-Dinitrochlorobenzene-Induced Skin Lesions in Mice.

Naturally occurring saponins have been reported to have anti-inflammatory and immunomodulatory effects. However, the effects of gracillin, a main saponin component of Dioscorea quinqueloba (D. quinqueloba), on atopic dermatitis (AD), have not been previously studied. The aim of this study was to determine whether gracillin isolated from D. quinqueloba has an anti-AD effect on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in SKH-1 hairless mice. Topical co-treatment of gracillin and DNCB for two weeks markedly reduced symptoms typical of AD (redness, itching, swelling and skin lichenification), decreased transepidermal water loss (TEWL) and increased skin hydration. In addition, gracillin strongly inhibited PI-induced IL-4 expression in RBL-2H3 cells and in the skins of AD mice. Our results suggest gracillin is a potential candidate for the prevention and treatment of AD and other inflammatory skin disorders.

Isolation of tyrosinase and melanogenesis inhibitory flavonoids from Juniperus chinensis fruits.

A new biflavonoid, amentoflavone-7-O-ß-D-glucoside, and thirteen known flavonoids were isolated from the fruits of Juniperus chinensis using a bioactivity-guided method and their tyrosinase inhibitory effects were tested using a mushroom tyrosinase bioassay. Two isolates, hypolaetin-7-O-ß-D-glucoside and quercetin-7-O-α-L-rhamnoside, were found to reduce tyrosinase activity at a concentration of 50 µM. Quercetin-7-O-α-L-rhamnoside attenuated cellular tyrosinase activity and melanogenesis in α-MSH plus IBMX-stimulated B16F10 melanoma cells. Molecular docking simulation revealed that quercetin-7-O-α-L-rhamnoside inhibits tyrosinase activity by hydrogen bonding with residues His85, His244, Thr261, and Gly281 of tyrosinase. Abbreviations: EtOH, ethanol; CH2Cl2, dichloromethane; EtOAc, ethylacetate; n-BuOH, n-butanol; MeOH, metanol; CHCl3,chloroform; DMSO, dimethylsulfoxide; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; α-MSH, α-melanocyte stimulating hormone; L-DOPA, L-3, 4-dihydroxyphenylalanine.

A new flavonoid from Stellera chamaejasme L., stechamone, alleviated 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in a murine model.

Stellera chamaejasme L. (family Thymelaeaceae), also known as 'Langdu', has been traditionally used to treat of skin-related diseases, such as, psoriasis and skin ulcers. The aim of this study was to identify the biologically active component of S. chamaejasme and evaluate its preventive effects on IL-4 and mast cell degranulation in RBL-2H3 cells and on the development of atopic dermatitis (AD) in 2,4-dinitrochlorobenzene (DNCB)-treated SKH-1 hairless mice. A novel flavonoid, genkwanin 5-O-xylosyl(1 → 2)glucoside (named stechamone), and three known compounds (umbelliferone, luteolin, and luteolin-7-O-glucoside) were isolated from the aerial parts of S. chamaejasme using chromatographic methods. Of these four compounds, stechamone most potently inhibited IL-4 production and mast cell degranulation in RBL-2H3 cells. Topical application of 0.5% stechamone improved atopic skin symptoms, including, erythema (redness), pruritus (itching), exudation (weeping), excoriation (peeling), and lichenification (skin thickening) in DNCB-treated AD mice by accelerating skin barrier recovery function and suppressing inflammatory cell infiltration. In addition, stechamone attenuated DNCB-induced increases in IL-4 (an inflammatory TH2 cytokine) expression and in serum IgE levels in our murine model of AD. DNCB induced AD-like skin lesions, but treatment with stechamone exhibited strong anti-atopic activity by regulating skin barrier function and reducing inflammatory responses. The results obtained suggest stechamone is a potential anti-atopic agent and treatment for skin inflammatory diseases.

Juniperus chinensis Fruits Attenuate Oxazolone- and 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis Symptoms in Mice.

Juniperus chinensis, commonly Chinese juniper, has been used for treating inflammatory diseases. This study aimed to investigate anti-atopic dermatitis (AD) effects of standardized J. chinensis fruits extract on murine oxazolone- and 2,4-dinitrochlorobenzene (DNCB)-induced models of AD. Ear swelling, epidermis thickening, and eosinophils infiltration in the oxazolone-mediated dermatitis of BALB/c mice were significantly reduced upon topical application of J. chinensis fruits 95% EtOH extract (JCE). Besides, transdermal administration of JCE to SKH-1 hairless mice inhibited the development of DNCB-induced AD-like skin lesions by suppressing transepidermal water loss and improving skin hydration. Decreased total serum immunoglobulin E (IgE) and interleukin (IL)-4 levels could be observed in atopic dorsal skin samples of JCE-treated group. According to the phytochemical analysis, JCE was found to contain isoscutellarein-7-O-ß-D-xyloside, cupressuflavone, and amentoflavone as main compounds. Therapeutic attempts with the J. chinensis fruits might be useful in the treatment of AD and related skin inflammatory diseases.

Ameliorative effects of Juniperus rigida fruit on oxazolone- and 2,4-dinitrochlorobenzene-induced atopic dermatitis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruits of Juniperus rigida have been used in Korean traditional medicine for the treatment of inflammatory diseases in humans such as rheumatoid arthritis. AIM OF THE STUDY: This study aimed to investigate the anti-atopic properties of J. rigida fruit in in vivo murine atopic dermatitis (AD) models. METHODS AND RESULTS: BALB/c mouse ears ad SKH-1 hairless mice stimulated with oxazolone (4 weeks) and DNCB (3 weeks), respectively, were treated with the 1% Juniperus rigida fruit EtOH extract (JFE). The JFE improved AD symptoms in both oxazolone- and DNCB-induced AD mice by accelerating skin barrier recovery function and suppressing the overproduction of serum immunoglobulin E (IgE) and interleukin 4 (IL-4). The JFE was found to contain isoscutellarein-7-O-ß-xylopyranoside, cupressuflavone, podocarpusflavone A, and hinokiflavone as major components based on phytochemical analysis. Eight flavonoids were isolated from JFE, and of those, cupressuflavone and isoscutellarein-7-O-ß-xylopyranoside strongly down-regulated IL-4 expression and ß-hexosaminidase release in RBL-2H3 cells. CONCLUSION: Therapeutic attempts with J. rigida fruit and its active components might be useful in treating AD and related skin inflammatory diseases.

Dioscorea quinqueloba Ameliorates Oxazolone- and 2,4-Dinitrochlorobenzene-induced Atopic Dermatitis Symptoms in Murine Models.

Dioscorea quinqueloba has been used for food substances, as well as in herbal medicines for allergic diseases such as asthma. This study aimed to investigate the anti-atopic dermatitis (AD) effects of the total extract of D. quinqueloba rhizomes and active fractionson murine oxazolone- and 2,4-dinitrochlorobenzene-induced models of AD. Specific AD symptoms, such as erythema, ear swelling, and epidermis thickening, were significantly reduced in the oxazolone-mediated AD BALB/c mice upon topical application of D. quinqueloba rhizomes 95% EtOH extract (DQ). DQEA (D. quinqueloba rhizomes EtOAc fraction) was beneficial for protecting the skin barrier against AD in DNCB-sensitized SKH-1 hairless mice. Decreased total serum IgE and IL-4 levels could be observed in atopic dorsal skin samples of the DQEA-treated group. On the basis of the phytochemical analysis, DQEA was found to contain dioscin and gracillin as its main compounds. Therapeutic applications with D. quinqueloba might be useful in the treatment of AD and related inflammatory skin diseases.

The Standardized Extract of Juniperus communis Alleviates Hyperpigmentation in Vivo HRM-2 Hairless Mice and in Vitro Murine B16 Melanoma Cells.

In European folk medicine, the fruits of Juniperus communis are used in the treatment of skin-related disorders such as skin infection, itching, and psoriasis. Previously, we reported that the EtOAc fraction of J. communis (EAJC) contained tyrosinase inhibition properties in vitro non-cellular experiment. The aim of this study was to evaluate anti-melanogenic effect of standardized EAJC on a hyperpigmentation animal model. Therapeutic effects of EAJC toward skin hyperpigmentation were confirmed by both in vivo experiment and in vitro cell-based assay. Skin depigmenting effect was detected by topical treatment of EAJC for 11 d to HRM-2 melanin-possessing hairless mice. Histologic findings including significantly decreased melanin depositions could be observed in dorsal skin samples of EAJC-treated group. In addition, the EAJC (50 µg/mL) attenuated melanin production through down-regulation of tyrosinase activity and protein expression in B16 murine melanoma cells. According to the phytochemical analysis, EAJC was found to contain hypolaetin-7-O-ß-D-xylopyranoside and isoscutellarein-7-O-ß-D-xylopyranoside as main components. Hypolaetin-7-O-ß-D-xylopyranoside was responsible for the skin-lightening effect of EAJC by reducing the number of melanocytes in dorsal skins of HRM-2 mice. The present study provided direct experimental evidence for skin-lightening effect of EAJC in UV-irradiated hairless mouse model. Therapeutic attempts with the J. communis might be useful in the management of skin pigmentation-related diseases.

Tyrosinase inhibitory flavonoid from Juniperus communis fruits.

The fruits of Juniperus communis have been traditionally used in the treatment of skin diseases. In our preliminary experiment, the MeOH extract of J. communis effectively suppressed mushroom tyrosinase activity. Three monoflavonoids and five biflavonoids were isolated from J. communis by bioassay-guided isolation and their inhibitory effect against tyrosinase was evaluated. According to the results of all isolates, hypolaetin 7-O-ß-xylopyranoside isolated from J. communis exhibited most potent effect of decreasing mushroom tyrosinase activity with an IC50 value of 45.15 µM. Further study provided direct experimental evidence for hypolaetin 7-O-ß-D-xylopyranoside-attenuated tyrosinase activity in α-MSH-stimulated B16F10 murine melanoma cell. Hypolaetin 7-O-ß-D-xylopyranoside from the EtOAc fraction of J. communis was also effective at suppressing α-MSH-induced melanin synthesis. This is the first report of the enzyme tyrosinase inhibition by J. communis and its constituent. Therapeutic attempts with J. communis and its active component, hypolaetin 7-O-ß-D-xylopyranoside, might be useful in treating melanin pigmentary disorders.