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Citrus Peel Wastes as Functional Materials for Cosmeceuticals
Abstract
The suitability of CPWs, by-products of the juice industry, was investigated as a source for the production of cosmeceuticals. Four kinds of CPWs, CW, CWE, CWER, and CWEA, were examined for their antioxidant potentials in terms of DPPH radical-scavenging ability for anti-wrinkle applications, inhibition of tyrosinase or melanin production for whitening products, and anti-inflammatory effects to treat various skin diseases such as atopic dermatitis and acne as well as for anti-bacterial activity against acne-inducing pathogens. Of the four extracts, CWER was the most potent tyrosinase inhibitor ( value: ), and CWEA () showed good antioxidative effects. CWE and CWEA samples had dose-dependent inhibitory effects on the melanin production. The cytotoxic effects of the four CPWs were determined by colorimetric MTT assays using human keratinocyte HaCaT cells. Most extracts exhibited low cytotoxicity at . These results suggest CPWs are attractive candidates for topical applications on the human skin.
... Soxhlet extraction method (Kim et al. 2008) was applied in hesperidin extraction process: dried fresh and fermented peel powder as tested samples. 2.0 g of each sample was weighed and transferred in extractor and from which hesperidin was extracted by 75% ethanol solution with the material-to-liquid ratio of 1:35 (w/v) under 85 °C for 2.5 h. ...
Mandarin peel is a by-product from mandarin canning industry containing multiple functional substances with useful properties such as antibacterial and antioxidant activities. To evaluate the effect of bioprocessing, fresh mandarin peels were fermented by Rhizopus stolonifer JP13 for 4 days and then the peels’ antioxidant and antimicrobial activities were tested. The flavonoiuds, hesperidin and VC contents in dry peels were also determined. The data showed that the fermented mandarin peels had promoted antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus flavus, and Candida albicans. An increased scavenging effect on free radicals, with 73.0% of·OH scavenging activities were obtained when compared with fresh mandarin peels. We also observed a significant increase on content of flavonoid (334%) and hesperindin (253.7%), a reduced scavenging effect on O2⁻ free radicals (13.94%), and a decrease content of VC (13.7%). The presaging of mandarin peels by Rhizopus stolonifer JP13 strain will promote the functional activities of mandarin peels and accelerate the process of manufacture Citri Reticulatae Pericarpium.
... The disposal of byproducts from C. unshiu, with annual yields of more than 60,000 tons from juice factories, creates a major problem on Jeju Island in the Korea Strait between Japan and South Korea. Handling, transportation, and disposal of this waste are costly, and the value of recycled materials is often sufficient to cover operating costs (2,3). However, citrus byproducts potentially present a rich source of natural flavonoids, owing to the large amount of peels produced that contain high concentrations of narirutin, naringenin, hesperidin, and nobiletin (4)(5)(6). ...
Citrus unshiu is an economically important fruit on Jeju Island, Korea, but byproducts are a major source of agricultural waste. The aim of this study is to examine changes in phytochemical, antioxidant, and antibacterial activities of four C. unshiu byproducts: citrus flesh byproduct (CFB), fermented citrus flesh byproduct (FCFB), citrus peel byproduct (CPB), and fermented citrus peel byproduct (FCPB). Fermented citrus byproducts (FCFB and FCPB) exhibited greater inhibition effect on radical scavenging abilities of 2,2-diphenyl-1-picrylhtdrazyl, 2,2’-azinobis(3-ethylbenzothiazolin-6-sulfonic acid)-diammonium salt, and superoxide anion compared with those of CFB and CPB. Total polyphenol contents of FCFB and FCPB were significantly increased compared to those of CFB and CPB. Significant bioconversion of the flavonoid glucosides into corresponding bioactive aglycones during citrus byproduct fermentation was observed. Fermented citrus byproducts exhibited antibacterial activity against Listeria monocytogenes and Escherichia coli suggesting that FCFB and FCPB are potent antioxidant and antibacterial sources due to the remarkable contents of bioactive compounds in them.
... Citrus processing generates high quantity of agricultural waste, and most of it is in the form of press-cakes, that are pricy to dispose due to the costs for handling and transport. In order to give value to this waste, an investigation was carried out into the anti-melanogenic effects of ethanol extracts of the press cakes of Citrus unshiu, which were mainly grown in Jeju Island in Korea and the fruit peel was extensively used in the traditional medicine as digestive or to treat severe and atopic dermatitis [10,11]. ...
In recent years, the amount of waste deriving from industrial processes has increased substantially. Many industries produce different types of disposable by-products, rich in valuable compounds. Their characterization and valorization could not only convert them into high value products with application in diverse biotechnological fields, such as Pharmaceutics, Food or Cosmetics, but would also reduce the waste environmental impact and the related treatment costs. There are many examples of cosmetic active ingredients deriving from fish, meat and dairy products, but in the present review we would like to focus on the potentialities and the current use of compounds and extracts deriving from agronomical disposable wastes in the cosmetic field. These types of products are effective, inexpensive and bio-sustainable, and thus represent a valid alternative to the regular plant derived extracts, more commonly adopted in cosmetic formulations. Moreover, if the waste products come from organic farming, they are certainly an even more valuable source of safe extracts for Cosmetics, since they lack any residual pesticide or potentially toxic chemical.
... However, the citrus-press cakes are one of the major problem of agricultural waste, with annual yields of more than 60 000 tonnes in Jeju Island alone from juice factories. This waste involves substantial costs for handling and transport to disposal location and the prices of recycled materials are often not high enough to cover operating costs [14,15] . Because of the London Dumping Convention, it will also become impossible to dump the waste into the ocean. ...
To investigate the suitability of citrus-press cakes, by-products of the juice industry as a source for the whitening agents for cosmetic industry.
Ethylacetate extracts of citrus-press cakes (CCE) were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese, tyrosinase-related protein-1 (TRP-1), TRP2, and microphthalmia-associated transcription factor (MITF) proteins. To apply the topical agents, citrus-press cakes was investigated the safety in human skin cell line. Finally flavonoid analysis of CCE was also determined by HPLC analysis.
Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern. The CCE inhibited tyrosinase, TRP-2, and MITF expressions in a dose-dependent manner. To test the applicability of CCE to human skin, we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells. The CCE exhibited low cytotoxicity at 50 µg/mL. Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin, narirutin, and hesperidin.
Considering the anti-melanogenic activity and human safety, CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.
... tyrosinase Mushroom-derived tyrosinase was used as the source of the enzyme for the entire study. Tyrosinase activity was determined as described previously with minor modifications 9 . Briefl y, each sample was assayed for tyrosinase inhibition by measuring its effect on tyrosinase activity using a 96-well reader Bio-Tek Instruments, Inc, Winooski, VT . ...
Melanogenesis is a well-known physiological response of human skin that may occur because of exposure to ultraviolet light, for genetic reasons, or due to other causes. In our efforts to find new skin lightening agents, palmitoleic acid was investigated for its ability to inhibit melanogenesis. In this study, palmitoleic acid's effect on melanin formation was assessed. Results indicated that palmitoleic acid was shown to down-regulate melanin content in a dose-dependent pattern. To clarify the target of palmitoleic acid action in melanogenesis, we performed Western blotting for tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF), which are key melanogenic enzymes. Palmitoleic acid inhibited tyrosinase, TRP-2, and MITF expressions in a dose-dependent manner. However, it did not inhibit TRP-1 expression. In order to assess its usefulness in future cosmetic product applications, the cytotoxic effects of the palmitoleic acid were also determined by colourimetric MTT assays using human keratinocyte HaCaT cells. Palmitoleic acid exhibited no cytotoxicity at 500 muM in a human cell line. Therefore, this study suggests that palmitoleic acid is a candidate anti-melanogenic agent, and it might be effective in hyperpigmentation disorders.
... These plant-material wastes may contain high levels of biological compounds that can adversely affect the environment. However, these biological compounds may also show many beneficial activities in humans, including antioxidant, antityrosinase, and antiinflammatory activities [1,2]. A. koreanum is an economically important fruit of Jeju Island. ...
The Acanthopanax koreanum fruit is a popular fruit in Jeju Island, but the byproducts of the alcoholic beverage prepared using this fruit are major agricultural wastes. The fermentability of this waste causes many economic and environmental problems. Therefore, we investigated the suitability of using A. koreanum fruit waste (AFW) as a source of antiinflammatory agents. AFWs were extracted with 80% EtOH. The ethanolic extract was then successively partitioned with hexane, CH(2)Cl(2), EtOAc, BuOH, and water. The results indicate that the CH(2)Cl(2) fraction (100 microg/mL) of AFW inhibited the LPS-induced nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production in RAW 264.7 cells by 79.6% and 39.7%, respectively. These inhibitory effects of the CH(2)Cl(2) fraction of AFWs were accompanied by decreases in the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and iNOS and COX-2 mRNA in a dose-dependent pattern. The CH(2)Cl(2) fraction of AFWs also prevented degradation of IkappaB-alpha in a dose-dependent manner. Ursolic acid was identified as major compound present in AFW, and CH(2)Cl(2) extracts by high performance liquid chromatography (HPLC). Furthermore using pure ursolic acid as standard and by HPLC, AFW and CH(2)Cl(2) extracts was found to contain 1.58 mg/g and 1.75 mg/g, respectively. Moreover, we tested the potential application of AFW extracts as a cosmetic material by performing human skin primary irritation tests. In these tests, AFW extracts did not induce any adverse reactions. Based on these results, we suggest that AFW extracts be considered possible anti-inflammatory candidates for topical application.
... A variety of herbs and plants have traditionally been used in oriental folk medicine to treat skin diseases (9,10). The extracts of many plants exhibit significant biological activities, including anti-inflammatory activities (11)(12)(13). Four Oenothera species, O. biennis, O. laciniata, O. lamarckiana, and O. odorata, are found in Korea. ...
We elucidated the pharmacological and biological effects of Oenothera laciniata extracts on the production of inflammatory mediators in macrophages. The CH(2)Cl(2) fraction of O. laciniata extract effectively inhibited LPS-induced NO, PGE(2), and proinflammatory cytokine production in RAW264.7 cells. These inhibitory effects of the CH(2)Cl(2) fraction of O. laciniata were accompanied by decreases in the expression of iNOS and COX-2 proteins and iNOS, COX-2, TNF-alpha, IL-1beta, and IL-6 mRNA. Asiatic acid and quercetin were present in the HPLC fingerprint of the O. laciniata extract. We tested the potential application of O. laciniata extract as a cosmetic material by performing primary skin irritation tests. In New Zealand white rabbits, primary irritation tests revealed that application of O. laciniata extracts (1%) did not induce erythema or edema formation. Human skin primary irritation tests were performed on the normal skin (upper back) of 30 volunteers to determine if any material in O. laciniata extracts had irritation or sensitization potential. In these assays, O. laciniata extracts did not induce any adverse reactions. Based on these results, we suggest that O. laciniata extracts be considered possible anti-inflammatory candidates for topical application.
Citrus is an economically important fruit for Jeju Island, but its peel also is one of the major sources of agricultural waste. Due to its fermentability, this waste causes many economic and environmental problems. Therefore it is worthwhile to investigate ways to make use of this citrus waste generated by the juice industry. The aim of this study was to examine the chemical composition of the essential oil obtained from citrus peel waste by hydrodistillation and to subsequently test the efficacy of this essential oil against a diverse range of microorganisms comprising drug-susceptible and drug-resistant skin pathogens. The chemical composition of the essential oil was analysed by GC-MS, revealing that a total of 6 compounds comprised 94.5% of the total oil. The oil contained limonene (80.51%), γ-terpinene (6.80%), cymene (4.02%), β-myrcene (1.59%), α-pinene (1.02%) and α-terpinolene (0.56%). The oil exhibited promising antibacterial effects against drug-susceptible and drug-resistant skin pathogens as evidenced by the diameter of zones of inhibition and MIC values. The effects of citrus peel waste essential oil (CPWE) on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined in this study. The addition of CPWE (100 µg mL -1) to the medium with LPS largely inhibited the production of NO by 42.5%. The number of viable activated macrophages was not altered by CPWE, as determined by MTT assays, indicating that the inhibition of NO synthesis by CPWE was not simply due to cytotoxic effects. In addition CPWE (6.125 to 100 µg mL -1) inhibited NO production in a dose-dependent manner. Based on these results, we suggest the possibility that CPWE may be considered as an antibacterial and anti-inflammatory agent.
Plant phenolic compounds isolated from a 70% aqueous acetone extract of the leaves of Malus doumeri A. CHEV. var. formosana (KAWAK. & KOIDZ.) S. S. YING, a type of Taiwanese indigenous plant, were evaluated for potential application in the field of skin care. A phytochemical investigation of the active fractions resulted in the isolation of seven compounds of which the structures were identified by spectroscopic characterization. In the present study, the isolated phenolic compounds were evaluated for their free radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the superoxide radicals, anti-elastase, and for their anti-matrix metalloproteinase-1 (MMP-1) activity in human skin fibroblast cells. Of these compounds, 3-hydroxyphloridzin (2), 3-hydroxyphloretin (6), and quercetin (7) exhibited the strongest DPPH and superoxide radical-scavenging activities. The IC50 values of these compounds were 9.2, 7.7, and 15.4 microM, respectively, for the DPPH radical, and 25.0, 19.6, and 42.6 microM, respectively, for the superoxide radical. 3-Hydroxyphloridzin (2) and 3-hydroxyphloretin (6) also showed xanthine oxidase inhibitory activity, with IC(50) values of 52.1 and 22.4 muM, respectively. In the test for elastase inhibitory activity, phloretin (5) and 3-hydroxyphloretin (6) were the most potent compounds. Phloretin (5), 3-hydroxyphloretin (6), and quercetin (7) showed better inhibition of MMP-1 production in fibroblast cells. To the best of our knowledge, this is the first time that the active phenolic compounds from M. doumeri var. formosana have been isolated, reported, and described. The above results suggest that the extract of M. doumeri var. formosana containing phenolic compounds could be suitable naturally occurring active constituents for use in anti-aging or cosmetic products.
The infiltration of both monocyte and activated T cells in the skin is one of critical steps in the development of UVB-induced inflammation. Upregulation of adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1) on the surface of keratinocytes plays an important role in this process. In this study, we examined the molecular mechanism responsible for UVB-induced expression of ICAM-1 and subsequent monocyte adhesion by keratinocyte. We observed that (1) UVB induced protein and mRNA expression of ICAM-1 in a dose- and time-dependent manner in human keratinocyte cell HaCaT; (2) UVB induced the translocation of NF-kappaB and inhibition of NF-kappaB by NF-kappaB inhibitors suppressed UVB-induced mRNA and protein expression of ICAM-1; (3) UVB increased the intracellular level of reactive oxygen species (ROS) by HaCaT cells; (4) UVB-induced increase of intracellular ROS level was suppressed by pretreatment with diphenyl iodonium (DPI) and N-acetyl cysteine (NAC); and (5) inhibition of UVB-induced ROS production by DPI or NAC suppressed UVB-mediated translocation of NF-kappaB, expression of ICAM-1 and subsequent monocyte adhesion in HaCaT cells. These results suggest that UVB-induced ROS is involved in the translocation of NF-kappaB which is responsible for expression of ICAM-1 and subsequent increased monocyte adhesion in human keratinocyte.
Citrus juice centrifugation pulp is the semi-solid product obtained from the industrial centrifugation of juices, to obtain a clear juice. This waste causes many economic and environmental problems because of its fermentability. In this paper we describe a method which makes it possible to obtain animal feed from citrus juice centrifugation pulp. To this end, alkaline and/or enzymatic treatments were carried out on the centrifugation pulp. These treatments facilitate pressing and so help to produce a material which, using suitable methods, may be dried. Enzyme treatment proved to be the most efficient of the methods under investigation designed to favour the pressing of the pulp. The product obtained with this method showed excellent digestibility in vitro and its protein content, although not especially high, compared favourably with that of many other agroindustrial waste products currently used as components of animal feed.
Varied effects of chemical or biological compounds on mammalian pigmentation have been reported by many groups, but to date, no standardized method has established necessary and/or optimal parameters for testing such agents. A standardized method has been developed to screen compounds with potential effects on pigmentation. The protocol comprises basic parameters to analyze melanogenic effects and allows for further characterization of candidate compounds, providing important insights into their mechanism of action. In this protocol (termed STOPR, for standardized testing of pigmentation regulators), compounds are initially screened using purified tyrosinase and are then tested on melanocytes in culture. After treatment of melanocytes with potentially bioactive compounds, cell proliferation and viability, total melanin accumulated, and melanogenic potential are measured. This protocol is an important first step in characterizing chemical regulation of effects on melanogenesis. When bioactive candidate compounds are identified, testing may proceed for pharmacological or otherwise commercial applications in coculture and/or organ culture models followed by in vivo testing. As an application of this method, results for compounds known to stimulate and/or inhibit melanogenesis (including arbutin, hydroquinone, kojic acid, melanocyte-stimulating hormone, and thymidine dimers) as well as some commercial skin whiteners are reported.
The allelopathic potential of Citrus junos fruit waste after juice extraction was investigated. Aqueous methanol extracts of peel, inside and seeds separated from the fruit waste inhibited the growth of the roots and shoots of alfalfa (Medicago sativa L.), cress (Lepidium sativum L.), crabgrass (Digitaria sanguinalis L.), lettuce (Lactuca sativa L.), timothy (Pheleum pratense L.), and ryegrass (Lolium multiflorum Lam.). The inhibitory activity of the peel extract was greatest and followed by that of the inside and seed extracts in all bioassays. Significant reductions in the root and shoot growth were observed as the extract concentration was increased. The concentrations of abscisic acid-beta-d-glucopyranosyl ester (ABA-GE) in peel, inside and seeds separated from the C. junos fruit waste were determined, since ABA-GE was found to be one of the main growth inhibitors in C. junos fruit. The concentration was greatest in the peel, followed by the inside and seeds; there was a good correspondence between these concentrations and the inhibitory activities of the extracts. This suggests that ABA-GE may also be involved in the growth inhibitory effect of C. junos waste. These results suggested that C. junos waste may possess allelopathic potential, and the waste may be potentially useful for weed management.
Recently, intense interest has focused on the antioxidant properties of natural products. In particular, Chinese herbal medicines (CHM) have become hot topics for life science researchers since many are reported to possess cardioprotective compounds, many of which remain to be identified. Indeed, the exact mechanisms by which CHM work remain unknown. Although many of these herbal remedies are undoubtedly efficacious, few have been scientifically investigated for their active chemical constituents and biological activities. We have previously reported higher activities of antioxidant defence enzymes such as superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferases in the liver of rats treated with the herb Salvia miltiorrhiza in a model of acute myocardial infarction. Using well established in vitro antioxidant assays employing 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and diphenyl-l-picrylhydrazyl (DPPH) we have shown that in addition to elevating endogenous antioxidant enzyme activity, Salvia miltiorrhiza and other CHM traditionally used for cardiovascular disorders (such as Rhizoma ligustici, Herba leonuri, Radix achyranthis bidentatae, and Camellia sinensis) contain potent antioxidant moieties in addition to their phenolic constituents. Furthermore, these novel non-phenolic components are effective inhibitors of oxidative reactions mediated by the inflammatory oxidants, peroxynitrite,hypochlorous acid and hydroxyl radical as well as iron-dependent lipid peroxidation. In this review, we discuss the various antioxidant properties of CHM in the context of their biochemical mechanisms.
Honokiol and magnolol, two major phenolic constituents of Magnolia sp., have been known to exhibit antibacterial activities. However, until now, their antibacterial activity against Propionibacterium sp. has not been reported. To this end, the antibacterial activities of honokiol and magnolol were detected using the disk diffusion method and a two-fold serial dilution assay. Honokiol and magnolol showed strong antibacterial activities against both Propionibacterium acnes and Propionibacterium granulosum, which are acne-causing bacteria. The minimum inhibitory concentrations (MIC) of honokiol and magnolol was 3-4 microg/ml (11.3-15 microM) and 9 microg/ml (33.8 microM), respectively. In addition, the killing curve analysis showed that magnolol and honokiol killed P. acnes rapidly, with 10(5) organisms/ml eliminated within 10 min of treatment with either 45 microg (169.2 microM) of magnolol or 20 microg (75.2 microM) of honokiol per ml. The cytotoxic effect of honokiol and magnolol was determined by a colorimetric (3-(4,5-dimetyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) (MTT) assay using two animal cell lines, human normal fibroblasts and HaCaT. In this experiment, magnolol exhibited lower cytotoxic effects than honokiol at the same concentration, but they showed similar cytotoxicity when triclosan was employed as an acne-mitigating agent. In addition, they reduced secretion of interleukin-8 and tumor necrosis factor alpha (TNF-alpha) induced by P. acnes in THP-1 cells indicating the anti-inflammatory effects of them. When applied topically, neither phenolic compound induced any adverse reactions in a human skin primary irritation test. Therefore, based on these results, we suggest the possibility that magnolol and honokiol may be considered as attractive acne-mitigating candidates for topical application.
This review summarizes the multifaceted aspects of antioxidants and the basic kinetic models of inhibited autoxidation and analyzes the chemical principles of antioxidant capacity assays. Depending upon the reactions involved, these assays can roughly be classified into two types: assays based on hydrogen atom transfer (HAT) reactions and assays based on electron transfer (ET). The majority of HAT-based assays apply a competitive reaction scheme, in which antioxidant and substrate compete for thermally generated peroxyl radicals through the decomposition of azo compounds. These assays include inhibition of induced low-density lipoprotein autoxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), and crocin bleaching assays. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes color when reduced. The degree of color change is correlated with the sample's antioxidant concentrations. ET-based assays include the total phenols assay by Folin-Ciocalteu reagent (FCR), Trolox equivalence antioxidant capacity (TEAC), ferric ion reducing antioxidant power (FRAP), "total antioxidant potential" assay using a Cu(II) complex as an oxidant, and DPPH. In addition, other assays intended to measure a sample's scavenging capacity of biologically relevant oxidants such as singlet oxygen, superoxide anion, peroxynitrite, and hydroxyl radical are also summarized. On the basis of this analysis, it is suggested that the total phenols assay by FCR be used to quantify an antioxidant's reducing capacity and the ORAC assay to quantify peroxyl radical scavenging capacity. To comprehensively study different aspects of antioxidants, validated and specific assays are needed in addition to these two commonly accepted assays.
Tea (Camellia sinensis) leaves contain various antioxidants such as ascorbic acid (1) and polyphenols. This study tries to clarify the molecular mechanisms underlying the antioxidative and radical-scavenging activities of these antioxidants, and the reactivities of each antioxidant have been compared against that of the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH, 2) using nuclear magnetic resonance (NMR) analysis. Catechol (3) and (+)-taxifolin (4) were oxidized to o-quinone by 2. However, ethyl protocatechuate (5) and quercetin (6) were not oxidized to o-quinone, even though they possess a catechol structure. The radical-scavenging ability of o-dihydroxyl phenolic compounds with a conjugated olefinic double bond (e.g., 6) was superior to that of compounds without this bond (e.g., 4), whereas the ability of o-dihydroxyl phenolic compounds possessing a conjugated carbonyl bond (5) was inferior to that of compounds lacking this bond (3). Vicinal trihydroxyl phenolic compounds with a conjugated olefinic double bond [e.g., myricetin (7)] had an inferior scavenging ability as compared with compounds lacking this bond [e.g., pyrogallol (8)], but 7 was a better scavenger than compounds with a conjugated carbonyl double bond [e.g., ethyl gallate (9)]. In addition, vicinal trihydroxyl phenolic compounds (e.g., 9) were superior to o-dihydroxyl phenolic compounds (e.g., 6). Finally, 1 scavenged radicals more quickly than 8.
The suitability of citrus peels, generated as a by-product of the juice industry, as a source of antioxidants was investigated. Citrus peel powder was prepared by lyophilizing 70% ethanol extract from citrus peels. Extraction was carried out at room temperature (20 degrees C) for 72 h. The extract was subjected to gamma-irradiation treatment (20 kGy). The aqueous solutions of citrus peel powder were examined for color characteristics and antioxidant potential in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, beta-carotene bleaching and nitrite scavenging activities. There were significant changes in Hunter color values due to irradiation. The a*- and b*-values decreased due to radiation treatment. DPPH radical scavenging, beta-carotene bleaching and nitrite scavenging activities were not affected by irradiation treatment. Nitrite scavenging activity was the highest in the extract at pH 1.2 followed by pH 4.2 and 6.0. These functional properties of the aqueous solution were found to be stable in heat treatment. It could significantly improve oxidative stability of lipids in fish meat system. Based on these results there may be opportunities to use citrus peel powder as a functional component in the food processing industry with gamma irradiation treatment improving its color characteristics without adversely influencing the functional properties.
Because tyrosinase catalyzes melanin synthesis, tyrosinase inhibitors are important in cosmetic skin-whitening. Oxidative stress contributes to skin aging and can adversely affect skin health, which means antioxidants active in skin cells may support skin health. We examined 25 traditional Chinese herbal medicines that might be useful for skin-whitening and skin health. Extracts (100microg/mL) were tested for cytotoxicity on human epidermal melanocytes (HEMn); 12 exhibited low cytotoxicity. Their effects on tyrosinase and melanin inhibitory activities and free radical scavenging activities were further assessed. Phenolic contents were evaluated using Folin-Ciocalteu reagent. Four herbs, Pharbitis nil, Sophora japonica, Spatholobus suberectus, and Morus alba, exhibited potent inhibitory effects on tyrosinase (IC(50) values 24.9, 95.6, 83.9, and 78.3microg/mL, respectively). Melanin inhibition was not dose-dependent. Sophora japonica (IC(50): 14.46microg/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH); 1.95microg/mL, hydroxyl radical) and Spatholobus suberectus (IC(50): 10.51microg/mL, DPPH; 4.36microg/mL, hydroxyl radical) showed good antioxidative activities and high phenolic contents (255 and 189mg of gallic acid/g extract, respectively). Among active anti-tyrosinase extracts, Sophora japonica and Spatholobus suberectus were especially potent in HEMn cells in terms of free radical scavenging effects and high phenolic contents, making them the strongest candidates for cosmetic application found in the current study.
Researchers are finding new sources of candidate materials that are cheap, abundant, and sustainable to establish ethanol as an alternative to petroleum fuel. In Florida, researchers at the USDAs Citrus and Subtropical Products Research Laboratory are looking for ways to use the ∼ 3 million ton of wet pulp and peel waste produced every year by citrus-processing companies. The waste could yield 50 million gal/yr of ethanol fuel. Bill Wildmer, the researcher heading the project, and his USDA colleagues have demonstrated the concept with a 100-gal ethanol-production system. They are currently working with Renewable Spirits LLC to conduct full-scale tests at a 10,000-gal pilot facility at the start of the citrus season in November. The ethanol produced at the new facility could replace MTBE as a gasoline additive in central or southern California.
An overview of agents causing hypopigmentation in human skin is presented. The review is organized to put forward groups of biological and chemical agents. Their mechanisms of action cover (i) tyrosinase inhibition, maturation and enhancement of its degradation; (ii) Mitf inhibition; (iii) downregulation of MC1R activity; (iv) interference with melanosome maturation and transfer; (v) melanocyte loss, desquamation and chemical peeling. Tyrosinase inhibition is the most common approach to achieve skin hypopigmentation as this enzyme catalyses the rate-limiting step of pigmentation. Despite the large number of tyrosinase inhibitors in vitro, only a few are able to induce effects in clinical trials. The gap between in-vitro and in-vivo studies suggests that innovative strategies are needed for validating their efficacy and safety. Successful treatments need the combination of two or more agents acting on different mechanisms to achieve a synergistic effect. In addition to tyrosinase inhibition, other parameters related to cytotoxicity, solubility, cutaneous absorption, penetration and stability of the agents should be considered. The screening test system is also very important as keratinocytes play an active role in modulating melanogenesis within melanocytes. Mammalian skin or at least keratinocytes/melanocytes co-cultures should be preferred rather than pure melanocyte cultures or soluble tyrosinase.
All organisms, from simple invertebrates to complex human beings, exist in different colors and patterns, which arise from the unique distribution of pigments throughout the body. Pigmentation is highly heritable, being regulated by genetic, environmental, and endocrine factors that modulate the amount, type, and distribution of melanins in the skin, hair, and eyes. In addition to its roles in camouflage, heat regulation, and cosmetic variation, melanin protects against UV radiation and thus is an important defense system in human skin against harmful factors. Being the largest organ of the body that is always under the influence of internal and external factors, the skin often reacts to those agents by modifying the constitutive pigmentation pattern. The focus of this review is to provide an updated overview of important physiological and biological factors that increase pigmentation and the mechanisms by which they do so. We consider endocrine factors that induce temporary (e.g., during pregnancy) or permanent (e.g., during aging) changes in skin color, environmental factors (e.g., UV), certain drugs, and chemical compounds, etc. Understanding the mechanisms by which different factors and compounds induce melanogenesis is of great interest pharmaceutically (as therapy for pigmentary diseases) and cosmeceutically (e.g., to design tanning products with potential to reduce skin cancer risk).
To develop effective skin-lightening agents, we tested medicinal herbal extracts for their melanogenic-inhibitory activities. We isolated a sesquiterpenoid compound from the extract of Atractylodis Rhizoma Alba using the bioactivity-guided fractionation and identified it as selina-4(14),7(11)-dien-8-one (compound 1) with spectroscopic methods. Compound 1 dramatically reduced melanin synthesis of melan-a cells without any apparent cytotoxicity. Compound 1 did not inhibit cell-free tyrosinase activity but decreased tyrosinase activity in melanocytes. These effects were attributed to reduced expression of melanogenic enzymes such as tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2). These results suggest that compound 1 may be an effective skin-lightening agent that regulates expression of melanogenic enzymes.
Post-treatment with nobiletin (5,6,7,8,3',4'-hexamethoxy flavone), which was purified from the fruit peel of Citrus sunki Hort. ex Tanaka, at concentration 6-50 microM significantly suppressed NF-kappaB transcriptional activation, NO and PGE(2) production, and iNOS and COX-2 protein expression in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Nobiletin inhibited neither LPS-induced phosphorylation/degradation of inhibitory kappaB-alpha nor LPS-induced nuclear translocation of NF-kappaB. However, it interrupted the DNA-binding activity of activated NF-kappaB. As reactive oxygen species (ROS) are also known to regulate the activation of NF-kappaB, we tested the effect of nobiletin on LPS-induced ROS generation. Nobiletin significantly inhibited LPS-induced intracellular ROS production in RAW 264.7 cells. These results suggest that nobiletin may exert an anti-inflammatory effect through the interruption of NF-kappaB DNA-binding activity and the suppression of ROS generation.
In vitro Screening of Jeju Medicinal Plants for Cosmeceutical Materials
- Ss Kim
- Cg Hyun
- J Lee
- Jh Lim
- Jy Kim
- D Park
- Ss Kim
- Cg Hyun
- J Lee
- Jh Lim
- Jy Kim
- D Park
Hypopigmenting agents: an updated review on biological, chemical and clinical aspects
- F Solano
- S Briganti
- M Picardo
- G Ghanem