Inhibitory effect of mulberroside A and its derivatives on melanogenesis induced by ultraviolet B irradiation

Suppression of the inflammatory response by oxyresveratrol from the root bark of Artocarpus lakoocha Roxb against ultraviolet B-induced keratinocytes mediated by regulating p38 MAPK and AP-1

Oxyresveratrol is a polyphenolic compound present in the root bark of Artocarpus lakoocha Roxb. Several studies have reported on its antioxidant, anti-inflammatory, and whitening properties. In this study, we report for the first time that oxyresveratrol alleviates the cytotoxicity of ultraviolet B (UVB) radiation in keratinocytes- . We performed resazurin cell viability, reactive oxygen species (ROS), and Griess assays to investigate the cytoprotective and free radical-scavenging capabilities of oxyresveratrol. The antioxidant effect was demonstrated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging assay. The inhibition of inflammatory and apoptotic proteins by oxyresveratrol in UVB-irradiated keratinocytes was investigated using western blotting. Pretreated cells with oxyresveratrol exhibited reduced cell death upon UVB exposure, which was mediated by its antioxidant activity. Oxyresveratrol protected cells by inhibiting the mitogen-activated protein kinase p38 and its downstream target, AP-1 transcription factor. These factors led to a decrease in UVB-induced cell inflammation through iNOS and COX-2 expression. Furthermore, the Bax/Bcl-2 ratio was significantly decreased by oxyresveratrol at 10 μM and thus reduced cell apoptosis, as demonstrated by the Hoechst 33342 staining assay. This study revealed the photoprotective effects of oxyresveratrol against UVB\ irradiation in keratinocytes. This strongly supports the benefits of using oxyresveratrol as an ingredient in skincare products for the prevention of sun-damaged skin.

Maclura cochinchinensis (Lour.) Corner Heartwood Extracts Containing Resveratrol and Oxyresveratrol Inhibit Melanogenesis in B16F10 Melanoma Cells

This study aimed to isolate and purify resveratrol and oxyresveratrol from the heartwoods of Maclura cochinchinensis, and to evaluate their inhibitory effects on melanogenesis in B16F10 murine melanoma cells. A methanol maceration process yielded a crude extract comprising 24.86% of the initial mass, which was subsequently analyzed through HPTLC, HPLC, and LC-MS/MS. These analyses revealed the presence of resveratrol and oxyresveratrol at concentrations of 4.32 mg/g and 33.6 mg/g in the extract, respectively. Initial purification employing food-grade silica gel column chromatography separated the extract into two fractions: FA, exhibiting potent inhibition of both tyrosinase activity and melanogenesis, and FM, showing no such inhibitory activity. Further purification processes led to the isolation of fractions Y11 and Gn12 with enhanced concentrations of resveratrol (94.9 and 110.21 mg/g, respectively) and fractions Gn15 and Gn16 with elevated levels of oxyresveratrol (321.93 and 274.59 mg/g, respectively), all of which significantly reduced melanin synthesis. These outcomes affirm the substantial presence of resveratrol and oxyresveratrol in the heartwood of M. cochinchinensis, indicating their promising role as natural agents for skin lightening.

WITHDRAWN: The dysregulated autophagy in osteoarthritis: Revisiting molecular profile

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Restrained Mitf-associated autophagy by Mulberroside A ameliorates osteoclastogenesis and counteracts OVX-Induced osteoporosis in mice

Bone and mineral metabolism homeostasis accounts for the maintenance of normal skeletal remodeling. However, with aging and changes in hormone levels, over-activated osteoclasts disrupt homeostasis, induce osteoporosis, and even cause osteoporotic fractures, leading to an enormous economic burden. Despite the rapid development of pharmacological therapy for osteoporosis, safer and more effective treatments remain to be explored. Here, we demonstrate that Mulberroside A (Mul-A), a natural component extracted from mulberry bark and branches, effectively suppresses osteoclastogenesis in vitro and counteracts bone loss caused by ovariectomy (OVX). The mechanism underlying this effect involves the repression of autophagic flux during osteoclastogenesis by Mul-A, which can be attributed to the restrained expression of microphthalmia-related transcription factor (Mitf) and its nuclear translocation. Importantly, Mitf overexpression partially reverses the inhibitory effects of Mul-A on autophagy and osteoclastogenesis. Moreover, applying two autophagy agonizts, rapamycin and Torin 1, attenuates the osteoclastogenic regulatory role of Mul-A. Collectively, our study demonstrates that Mul-A damages osteoclast differentiation and ameliorates osteoporosis caused by estrogen deficiency by modulation of Mitf-associated autophagy, indicating its therapeutic potential against osteoporosis.

Oxyresveratrol attenuates bone resorption by inhibiting the mitogen-activated protein kinase pathway in ovariectomized rats

BACKGROUND

Bone is continuously produced by osteoblasts and resorbed by osteoclasts to maintain homeostasis. Impaired bone resorption by osteoclasts causes bone diseases such as osteoporosis and arthritis. Most pharmacological treatment of osteoporosis focuses on inhibiting osteoclast differentiation, often to restore osteoclast/osteoclast balance. However, recent osteoporosis treatments have various side effects. According to a recent study, resveratrol, known as a stilbenoid family, is known to increase bone density, and the osteoclast inhibitory effect was confirmed using oxyresveratrol, a stilbenoid family. Here, we investigated the effect of oxyresveratrol on osteoclast differentiation and an ovariectomized mouse model.

METHODS

Mouse leukemia monocyte/macrophage cell line RAW 264.7 was treated with oxyresveratrol, and cell cytotoxicity was confirmed by measuring MTT assay. Tartrate-resistant acid phosphatase (TRAP), an enzyme marker for osteoclasts, was confirmed by staining. In addition, osteoclast differentiation markers and MAPK-related markers were confirmed at the mRNA level and protein expression. The effect of oxyresveratrol was confirmed using ovariectomized mice. Deoxypyridinoline (DPD) was measured using mouse urine and TRAP activity was observed using serum. Bone mineral density was also measured using Micro-CT.

RESULTS

The polyphenol oxyresveratrol inhibited receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced osteoclast differentiation of RAW 264.7 cells. Furthermore, oxyresveratrol inhibited TRAP activity and actin-ring formation. Moreover, oxyresveratrol suppressed the phosphorylation of the RANKL-induced mitogen-activated protein kinases (MAPKs) p38, JNK, and ERK and significantly reduced the expression of bone differentiation markers (NFATc1, cathepsin K, and TRAP).

CONCLUSION

Oxyresveratrol inhibits osteoclast differentiation via MAPK and increases bone density in ovariectomized rats, suggesting it has therapeutic potential for bone diseases such as osteoporosis. We confirmed the osteoporosis prevention effect of OR in Raw 264.7 cells, and future studies should confirm the effect of OR using rat bone marrow-derived cells.

Mulberroside A alleviates osteoarthritis via restoring impaired autophagy and suppressing MAPK/NF-κB/PI3K-AKT-mTOR signaling pathways

Osteoarthritis (OA) is a trauma-/age-related degenerative disease characterized by chronic inflammation as one of its pathogenic mechanisms. Mulberroside A (MA), a natural bioactive withanolide, demonstrates anti-inflammatory properties in various diseases; however, little is known about the effect of MA on OA. We aim to examine the role of MA on OA and to identify the potential mechanisms through which it protects articular cartilage. In vitro, MA improved inflammatory response, anabolism, and catabolism in IL-1β-induced OA chondrocytes. The chondroprotective effects of MA were attributed to suppressing the MAPK, NF-κB, and PI3K-AKT-mTOR signaling pathways, as well as promoting the autophagy process. In vivo, intra-articular injection of MA reduced the cartilage destruction and reversed the change of anabolic and catabolic-related proteins in destabilized medial meniscus (DMM)-induced OA models. Thus, the study indicates that MA exhibits a chondroprotective effect and might be a promising agent for OA treatment.

Mulberroside F from In Vitro Culture of Mulberry and the Potential Use of the Root Extracts in Cosmeceutical Applications

Mulberry (Morus spp.) is primarily used in sericulture, and its uses also extend to the food, pharmaceutical, and cosmetic industries. Mulberry extracts are rich in many bioactive compounds that exhibit a wide range of biological properties. Mulberroside F (Moracin M-6, 3'-di-O-β-D-glucopyranoside), one of the bioactive compounds found in mulberry, has previously been reported as a whitening agent by inhibiting melanin synthesis and exhibiting antioxidant effects. However, there is still limited information on the presence of this compound in plants cultured in vitro. In this study, the mulberroside F content, biochemical, and cytotoxic properties of the extracts from mulberry cultured in vitro were determined. The results revealed that both root and callus were found to be a potential source of mulberroside F. Furthermore, the mulberroside F content was positively correlated with the inhibitory effects on tyrosinase activity. Cell viability assay also revealed that crude extract of the mulberry root has no cytotoxicity in both human keratinocyte cell line (HaCaT) and Vero cells. Taken together, mulberry tissue culture represents a possible alternative and continuous production of mulberroside F, which could be further utilized in cosmeceutical applications.

Screening and Structure-Activity Relationship for Selective and Potent Anti-Melanogenesis Agents Derived from Species of Mulberry (Genus Morus)

Tyrosinase is a multifunctional, copper-containing and rate-limiting oxidase that catalyses crucial steps in the melanogenesis pathway and is responsible for skin-pigmentation abnormalities in mammals. Numerous tyrosinase inhibitors derived from natural and synthetic sources have been identified as an objective for the development of anti-melanogenesis agents. However, due to side effects and lack of expected efficiency, only a small percentage of them are used for medical and cosmetic purposes. This critical review focuses on searching for novel active substances and recently discovered plant-derived anti-tyrosinase inhibitors from the Morus genus (Moraceae family). A detailed analysis of their structure-activity relationships is discussed. The information contained in this article is crucial for the cosmetics and medical industries, in order to show new directions for the effective search for natural anti-melanogenesis products (with satisfactory efficiency and safety) to treat and cure hyperpigmentation.

Identification and mechanism prediction of mulberroside A metabolites in vivo and in vitro of rats using an integrated strategy of UHPLC-Q-Exactive Plus Orbitrap MS and network pharmacology

Mulberroside A is a polyhydroxylated stilbene active component of Morus alba L. Studies have shown that it has antitussive, antiasthmatic, tyrosinase and antioxidation activities. However, little is known about the metabolism of it in vitro and in vivo. In our study, an integrated strategy on the basis of UHPLC-Q-Exactive Plus Orbitrap MS and network pharmacology was established to comprehensively research the metabolic characteristic of mulberroside A for the first time. Plasma, urine, feces and liver tissues of rats in the blank group and drug group were collected after intragastric administration of mulberroside A at a dose of 150 mg/kg, and rat liver microsomes were cultured for in vitro metabolism experiment. The biological samples were processed by different methods and analyzed in positive and negative ion modes using UHPLC-Q-Exactive Plus Orbitrap MS. A total of 72 metabolites were finally identified based on the accurate molecular mass, retention time, MS/MS spectra and related literatures combined with the Compound Discoverer 3.1. The metabolic pathways were mainly hydrolysis, glucuronidation, hydrogenation, sulfation, hydroxylation, methylation and their composite reactions. In addition, a network pharmacology method was used to predict the mechanism of action of mulberroside A and its metabolites. In the end, 7 metabolites with high gastrointestinal absorption and drug-likeness and 167 targets were screened by Swiss ADME and Swiss Target Prediction. 1702 items of GO analysis and 158 related signaling pathways of KEGG were enriched using Metascape. This study established a novel integrated strategy based on UHPLC-Q-Exactive Plus Orbitrap MS and network pharmacology, which could systematically analyze the metabolism behavior of mulberroside A in vivo and in vitro of rats and provide basis for the further research of mulberroside A.

Synergistic effects of novel herbal decoctions from Panax ginseng and Morus alba on tyrosinase activity and melanogenesis in vitro

Many medicinal plants such as a Panax ginseng and Morus alba (mulberry tree) have been widely used as depigmenting agents in Asia. To maximize their synergistic effects on melanogenesis, new herbal decoctions were created by mixing Ginseng Radix Alba (GR) and Mori Radicis Cortex (MC) at a ratio of 3:2 which called GMC decoction. A decoction of GR and Mori Ramulus (MR), which called GMR, was also formulated in order to compare the anti-melanogenic capacity. Combined decoctions, GMC and GMR, significantly decreased mushroom tyrosinase activity in vitro; however, single extracts, including MC and MR, showed weaker inhibitory activity. Melanin content assay and Fontana–Masson staining confirmed that two decoctions showed stronger inhibitory effects on the forskolin-induced melanin level in B16 cells, without cytotoxicity. Our findings suggest that ginseng in combination with mulberry tree enhances the anti-melanogenic effect in vitro.

Comprehensive characterization of naturally occurring antioxidants from the twigs of mulberry (Morus alba) using on-line high-performance liquid chromatography coupled with chemical detection and high-resolution mass spectrometry

INTRODUCTION

The mulberry tree (Morus alba L.) is a prolific source of biologically active compounds. There is considerable growing interest in probing M. alba twigs as a source of disruptive antioxidant lead candidates for cosmetic skin care product development.

OBJECTIVE

An integrated approach using high-performance liquid chromatography (HPLC) coupled with either chemical detection (CD) or high-resolution mass spectrometry (HRMS) was applied to the hydroalcoholic extract of M. alba to detect and identify lead antioxidant compounds, respectively.

MATERIAL AND METHODS

The twigs were weighed, powdered and homogenized using a mill and the extract was prepared using 70% aqueous ethanol. The antioxidant metabolites were detected with HPLC coupled with CD (based on the ORAC assay) and their structural identification was carried out using a Q-Exactive Orbitrap MS instrument.

RESULTS

Using this approach, 13 peaks were detected as overall contributors to the antioxidant activity of M. alba, i.e. mulberrosides (A & E), oxyresveratrol & its derivatives, moracin & its derivatives and a dihydroxy-octadecadienoic acid, which together accounted for >90% of the antioxidant activity, highlighting the effectiveness of the integrated approach based on HPLC-CD and HPLC-HRMS. Additionally, a (3,4-dimethoxyphenyl-1-O-β-D-apiofuranosyl-(1″ → 6')-O-β-D-glucopyranoside was also discovered for the first time from the twig extract and is presented here.

CONCLUSION

To our knowledge, this is the first report from M. alba twigs using HPLC-CD and HPLC-HRMS that identifies key compounds responsible for the antioxidant property of this native Chinese medicinal plant.

Formulation and Physicochemical Evaluation of a 3% Cream Using Crude 70% Ethanolic Extract of Morus alba L. Leaves for Skin Hyperpigmentation

Background: Treatment of hyperpigmentation disorders is a challenge because of the side effects of current topical treatments. Thus, research for potent alternatives, especially of herbal origin, with comparable potency and less side effects is ongoing. Mours alba L. is a perennial plant with multiple established pharmacological effects, including antimelanogenesis effect. This effect has been demonstrated from different parts of the plant, including twigs, root barks, and leaves by measuring tyrosinase inhibition, melanin content, and melanin index, and it has been attributed to phenolic compounds such as oxyresveratrol and moracin M, to name a few. However, no study has considered formulating the total phenolic compounds from the leaves of this plant so far. Objectives: The aim of this study was to extract phenolic compounds of leaves with repeated maceration using 70% ethanol, formulate the crude extract, inspect its physicochemical stability under accelerated conditions, and assay for microbial growth and active phenolic compounds. Methods: Total phenolic compounds were extracted using 70% ethanol with repeated maceration, and then they were concentrated. The extract was then assayed for total phenolic content using Folin-Ciocalteu’s reagent. A 3% cream of this extract was manufactured, and its physicochemical parameters, microbial growth, preservative effectiveness, and total phenolic content were examined. Results: The prepared 3% cream was completely stable and homogeneous during the accelerated conditions and passed the physicochemical, total phenolic content, and microbial tests. Conclusions: The manufactured cream is a promising formulation for in vivo use as a skin lightening agent.

Oxyresveratrol: Sources, Productions, Biological Activities, Pharmacokinetics, and Delivery Systems

Oxyresveratrol has recently attracted much research attention due to its simple chemical structure and diverse therapeutic potentials. Previous reviews describe the chemistry and biological activities of this phytoalexin, but additional coverage and greater accessibility are still needed. The current review provides a more comprehensive summary, covering research from 1955 to the present year. Oxyresveratrol occurs in both gymnosperms and angiosperms. However, it has never been reported in plants in the subclass Sympetalae, and this point might be of both chemotaxonomic and biosynthetic importance. Oxyresveratrol can be easily obtained from plant materials by conventional methods, and several systems for both qualitative and quantitative analysis of oxyresveratrol contents in plant materials and plant products are available. Oxyresveratrol possesses diverse biological and pharmacological activities such as the inhibition of tyrosinase and melanogenesis, antioxidant and anti-inflammatory activities, and protective effects against neurological disorders and digestive ailments. However, the unfavorable pharmacokinetic properties of oxyresveratrol, including low water solubility and poor oral availability and stability, have posed challenges to its development as a useful therapeutic agent. Recently, several delivery systems have emerged, with promising outcomes that may improve chances for the clinical study of oxyresveratrol.

Nutritional constituents of mulberry and their potential applications in food and pharmaceuticals: A review

Mulberry is a fast growing deciduous plant found in wide variety of climatic, topographical and soil conditions, and is widely distributed from temperate to subtropical regions. Due to presence of valuable phytochemical constituents, mulberry as a whole plant has been utilized as a functional food since long time. Mulberry fruits are difficult to preserve as they have relatively high water content. Therefore for proper utilization, different value-added products like syrups, squashes, teas, pestil sand köme, pekmez (turkuish by-products), yogurts, jams, jellies, wines, vinegar, breads, biscuits, parathas, and many more are made. In overseas, these value-added products are commercially sold and easily available, though in India, this versatile medicinal plant is still missing its identity at commercial and industrial scale. Leaves of mulberry are economically viable due to their important role in the sericulture industry since ancient times. Mulberries or its extracts exhibit excellent anti-microbial, anti-hyperglycaemic, anti-hyperlipidemic, anti-inflammatory, anti-cancer effects and is used to combat different acute and chronic diseases. Different parts of Morus species like fruits, leaves, twigs, and bark exhibit strong anti-tyrosinase inhibition activity that makes it a suitable candidate in cosmetic industries as a whitening agent. The current review provides a comprehensive discussion concerning the phytochemical constituents, functionality and nutraceutical potential of mulberry and as a common ingredient in various cosmetic products.

Inhibition of persimmon tannin extract on guinea pig skin pigmentation

BACKGROUND

In daily life, excessive exposure to ultraviolet light can lead to pigmentation.

AIMS

This study is to determine the mechanism of persimmon tannin extract in inhibiting pigmentation, to investigate whether the effect of persimmon tannin extract is superior to that of arbutin, and to detect the optimal concentration.

METHODS

In this study, the guinea pig pigmentation model was established by ultraviolet B (UVB) irradiation. With arbutin as a positive control, Masson-Fontana silver staining was used to observe the effects of persimmon tannin extract on melanin distribution in guinea pigs' skin tissue. Then, the tyrosinase activity was measured, and an Enzyme-linked immunosorbent assay was used to investigate the contents of antioxidant enzymes, inflammatory factors, and signaling pathway inhibitors in guinea pigs' skin tissue.

RESULTS

The results showed that compared with the model group, superoxide dismutase, catalase, glutathione peroxidase, DKK1 content of Wnt/-catenin signaling pathway inhibitors levels, and inhibitory tyrosinase activity were increased by 24.3%, 33.3%, 59.3%, 36.81%, and 17.16%, respectively. Meanwhile, the interleukin-6 and interleukin-8 expression were reduced by approximately 22.2% and 54%. The results also showed that persimmon tannin extract could significantly reduce melanin density. The differences in experimental results were statistically significant (P < .01).

CONCLUSIONS

Compared with the arbutin group, the medium-dose group (persimmon tannin extract of 20%) had a more significant effect on inhibiting pigmentation. Persimmon tannin could serve as a promising agent for preventing skin pigmentation. It is expected to provide ideas for the development of deep-processed persimmon products related to functional foods and cosmetics.

The pigmentation interference of bisphenol F and bisphenol A

Bisphenol A (BPA) and bisphenol F (BPF) are widely distributed in the environment and daily consumptions, leading to exposure toward human and environmental animals. The potential risk of bisphenol analogs on pigment and skin health is not well documented. In this study, we found that 0.05 mg/L BPF (tolerated daily intake (TDI) value of BPA) affected the particle size and color density of zebrafish melanin. While BPA caused less depigmentation effect toward zebrafish with effective concentration of 5.0 mg/L. The downregulation of melanin synthases induced by BPF is associated with the reduction in melanin. Molecular dynamics indicated that both BPF and BPA could act as ligands of zebrafish and human Tyr family proteins; however, these compounds have completely different energetics and spatial steric effects, potentially explaining their varying depigmentation effects. Additionally, an in vitro assay using A375 melanoma cells demonstrated that the inhibitory effect of BPF on human melanin production was primarily attributed to Tyr inhibition. These findings provide an important basis for understanding the molecular mechanisms of BPF and BPA in melanin inhibition, and the results reflect the skin pigmentation interference risk of these compounds, which are ubiquitous in everyday personal products.

Anti-Photoaging and Anti-Melanogenesis Effects of Fucoidan Isolated from Hizikia fusiforme and Its Underlying Mechanisms

Previous studies suggested that fucoidan with a molecular weight of 102.67 kDa, isolated from Hizikia fusiforme, possesses strong antioxidant activity. To explore the cosmeceutical potential of fucoidan, its anti-photoaging and anti-melanogenesis effects were evaluated in the present study. The anti-photoaging effect was investigated in ultraviolet (UV) B-irradiated human keratinocytes (HaCaT cells), where fucoidan effectively reduced the intracellular reactive oxygen species level and improved the viability of the UVB-irradiated cells without any cytotoxic effects. Moreover, fucoidan significantly decreased UVB-induced apoptosis in HaCaT cells by regulating the protein expression of Bax, Bcl-xL, PARP, and Caspase-3 in HaCaT cells in a concentration-dependent manner. The anti-melanogenesis effect of fucoidan was evaluated in B16F10 melanoma cells that had been stimulated with alpha-melanocyte-stimulating hormone (α-MSH), and fucoidan treatment remarkably inhibited melanin synthesis in α-MSH-stimulated B16F10 cells. Further studies indicated that fucoidan significantly suppressed the expression of tyrosinase and tyrosinase-related protein-1 and -2 (TRP-1 and-2) in B16F10 cells by down-regulating microphthalmia-associated transcription factor (MITF) through regulation of the ERK–MAPK (extracellular signal regulated kinase-mitogen activated protein kinase) pathway. Taken together, these results suggest that fucoidan isolated from H. fusiforme possesses strong anti-photoaging and anti-melanogenesis activities and can be used as an ingredient in the pharmaceutical and cosmeceutical industries.

Isobutylamido thiazolyl resorcinol for prevention of UVB-induced hyperpigmentation

BACKGROUND

Isobutylamido thiazolyl resorcinol (ITR, Thiamidol^® ) has been proposed as a potent tyrosinase inhibitor. A formulation containing ITR has recently shown promising efficacy for the treatment of some hyperpigmentary conditions.

OBJECTIVES

This study aimed to evaluate the efficacy and safety of ITR in the prevention of ultraviolet (UV)-induced hyperpigmentation in human skin.

MATERIALS AND METHODS

We performed a randomized, single-blinded, pilot study in 30 healthy participants. One arm was randomly assigned to receive an ITR-containing product for three weeks. Three hyperpigmented spots were induced by UVB irradiation on both arms after 3 weeks of ITR application. Outcome evaluations included measuring mean lightness index (*L) obtained by colorimeter, hyperpigmentation scores by visual analog scale (VAS), and adverse effects.

RESULTS

Both experimental sides showed no significant difference in terms of skin lightening after ITR application. However, the ITR-treated sides showed a statistically significant lower mean lightness index compared to control after an induction with UVB. In addition, the ITR-treated sides had an earlier improvement and resumed the normal skin color after 3 weeks post-UVB induction. A clinical evaluation by a blinded nontreating physician and subjects was more favorable on the ITR-treated side than the control side (P < .05). No significant side effect was noted.

CONCLUSIONS

ITR is an effective agent in the prevention of pigmentary change from UVB irradiation and may serve as a promising agent for preventing other hyperpigmentary conditions.

The in vitro and in vivo depigmenting activity of Coenzyme Q10 through the down-regulation of α-MSH signaling pathways and induction of Nrf2/ARE-mediated antioxidant genes in UVA-irradiated skin keratinocytes

Coenzyme CoQ10 (CoQ10), a ubiquinone compound, has been reported to inhibit tyrosinase activity and melanin production in melanoma B16F10 cells. However, the molecular mechanism underlying this inhibitory effect is poorly understood. In this paper we aimed to investigate the molecular mechanisms involved in the anti-melanogenic activity of CoQ10 (1-2 μM) in UVA (5 J/cm²)-irradiated keratinocyte HaCaT cells and α-MSH stimulated B16-F10 cells. It was observed that CoQ10 suppressed p53/POMC, α-MSH production as well as inhibited ROS generation in UVA-irradiated keratinocyte HaCaT cells. CoQ10 down-regulated the melanin synthesis in α-MSH-stimulated B16-F10 cells by suppressing the MITF expression by down regulating the cAMP mediated CREB signaling cascades. Furthermore, in vivo evidence demonstrated the inhibitory effect of CoQ10 on endogenous pigmentation in zebrafish. Increased nuclear Nrf2 translocation accompanied by the induction of HO-1 and γ-GCLC genes were observed in CoQ10 treated keratinocyte HaCaT cells. Notably, silencing of Nrf2 (siRNA transfection) significantly diminished CoQ10-mediated anti-melanogenic activity, as evidenced by impaired antioxidant HO-1 gene, uncontrolled ROS generation, and α-MSH production following UVA irradiation. To conclude, CoQ10 is an effective de-pigmention or skin-whitening agent and could be used in cosmetics for topical application.

Improvement of stilbenoid production by 2-hydroxypropyl-β-cyclodextrin in white mulberry (Morus alba L.) callus cultures

Mulberroside A, oxyresveratrol and resveratrol, commonly found in Morus alba L., are potent anti-aging phytostilbenes. In this study, the effect of the addition of 2-hydroxypropyl-β-cyclodextrin on the levels of phytostilbenes in M. alba callus cultures was investigated. Commercial cyclodextrin was used in the hydrolytic and culture processes of the M. alba callus cultures. The hydrolytic study indicated that 2-hydroxypropyl-β-cyclodextrin acted as a retardant for stilbenoid hydrolysis. It reduced mulberroside A deglycosylation and stabilised oxyresveratrol. The elicitation result showed that extracellular oxyresveratrol was increased by adding 2-hydroxypropyl-β-cyclodextrin to the culture media of both free and immobilised M. alba callus (>730-fold and >169-fold, respectively) compared with those of the control. However, the intracellular mulberroside A levels in the treatment groups did not increase compared with those of the control. The results show that the addition of 2-hydroxypropyl-β-cyclodextrin significantly changed the patterns and levels of the stilbenoids in M. alba callus cultures.

Isolation, Identification, and Quantification of Tyrosinase and α-Glucosidase Inhibitors from UVC-Irradiated Mulberry (Morus alba L.) Leaves

Methanol extracts from ultraviolet (UV) C-irradiated mulberry leaves (UVC-IML) exhibit stronger tyrosinase and α-glucosidase inhibitory activities than those from unirradiated mulberry leaves. Through a bioassay-guided fractionation and purification process, two oxyresveratrol derivatives, oxyresveratrol (ORT) and 4′-prenyloxyresveratrol (PORT), and six 2-arylbenzofuran derivatives [moracin B (MCB), moracin C (MCC), moracin M (MCM), moracin N (MCN), 6,5′-dimethoxymoracin M (DMMCM), and chalcomoracin (CMC)] were isolated from the methanol extract from UVC-IML. Their chemical structures were determined by UV, mass, and nuclear magnetic resonance spectrometry. ORT and PORT showed potent tyrosinase inhibitory activities with the half maximal inhibitory concentration (IC₅₀) values of 0.57 and 0.90 μM, respectively, and CMC exhibited significant tyrosinase and α-glucosidase inhibitory activity with IC₅₀ values of 5.61 and 6.00 μM, respectively. Levels of these eight compounds were increased significantly following irradiation compared with untreated mulberry leaves; ORTs increased approximately 4 fold and moracins increased 2~16 fold. These data suggest that UVC-IML may represent a promising source of nutraceuticals and cosmeceuticals for prevention of diabetes and skin aging.

Understanding the role of extracts from sea buckthorn seed residues in anti-melanogenesis properties on B16F10 melanoma cells

The hydroalcoholic extract of sea buckthorn (Hippophae rhamnoides L.) seed residues (HYD-SBSR) is a potential skin whitening agent. To test this material as a potential skin whitening agent, we identified and quantified the main chemical constituents of HYD-SBSR by using ultra-performance liquid chromatography coupled with quadruple time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) and ultra-high performance liquid chromatography coupled with triple quadruple mass spectrometry (UPLC-QQQ-MS). The anti-melanogenesis properties of HYD-SBSR on B16F10 mouse melanoma cells were analysed and the mechanism was measured on both the transcriptional and translational levels. About 24 compounds were identified. Kaempferol and its derivatives were the main compounds with a concentration of about (2796.22 ± 31.55) μg per g DW. The following order among the detected compounds was observed: quercetin and its derivatives > isorhamnetin and its derivatives > procyanidins. HYD-SBSR has a strong antioxidant activity but with a slight cytotoxic effect on B16F10 when treated with 45.45 μg mL-1 and 4.55 μg mL-1 respectively, for 48 h. HYD-SBSR has been found to significantly decrease melanin content (P < 0.01) in 24 h, 48 h, and 72 h. Additionally, strong inhibitory extracellular tyrosinase activities and decreasing intracellular tyrosinase activities were also observed (P < 0.01). HYD-SBSR shows inhibitory effects on the expression of tyrosinase (TYR) and tyrosinase-related protein 1 (TRP-1), and the secretion of TYR and TRP-1 proteins in cell lines. The protein levels of tyrosinase-related protein 2 (TRP-2) and microphthalmia-associated transcription factor (MITF) showed no significant difference. HYD-SBSR may inhibit melanin synthesis by decreasing the tyrosinase activity and down-regulating the expression of TYR and TRP-1 which were probably induced by other transcriptional factors rather than MITF.

Effects of volatile oil from ginger on the murine B16 melanoma cells and its mechanism

In this study, the inhibitory effects of volatile oil from ginger on melanogenesis and its antioxidant characteristics were investigated. The effects of volatile oil from ginger on cell proliferation, melanin content and tyrosinase activity were determined using a microplate reader. In addition, the expression of melanogenesis-related protein was determined by western blotting. The results indicate that the tested concentrates of volatile oil from ginger showed inhibitory effects on cell proliferation and melanogenesis. This revealed that volatile oil from ginger exhibited apparent capacities for scavenging ROS and lipid peroxidation. Furthermore, volatile oil from ginger improved the activities of GSH, SOD and CAT in B16 melanoma cells. These results demonstrated that volatile oil from ginger suppressed melanin synthesis through its antioxidant properties and the inhibitory effects on tyrosinase activity and melanogensis-related proteins. Hence, volatile oil from ginger could be used as an effective skin-whitening agent applied in food industry.

Isolation and characterization of a novel chalcone synthase gene family from mulberry

Chalcone synthase (CHS) is the pivotal enzyme that catalyzes the first committed step of the phenylpropanoid pathway leading to flavonoids. Here, five CHS genes were determined in mulberry (Morus atropurpurea Roxb.). Interestingly, phylogenetic analysis tended to group three MaCHSs in the stilbene synthase (STS) family and initially annotated these as MaSTSs. A co-expression system that harbored a 4-coumarate:CoA ligase gene and one of the candidate genes was established to determine the functions of this novel gene family. The fermentation result demonstrated that MaSTS in fact encoded a CHS enzyme, and was consequently retermed MaCHS. Tissue-specific expression analysis indicated that MaCHS1/MaCHS2 was highly abundant in fruit, and MaCHS4 had significant expression in root bark, stem bark and old leaves, while MaCHS3 and MaCHS5 were more expressed in old leaves. Subcellular localization experiments showed that MaCHS was localized to the cytoplasm. Transcription levels suggested MaCHS genes were involved in a series of defense responses. Over-expression of MaCHS in transgenic tobacco modified the metabolite profile, and resulted in elevated tolerance to a series of environmental stresses. This study comprehensively evaluated the function of MaCHS genes and laid the foundation for future research on MaCHS in mulberry.

Inhibitory effect of a genistein derivative on pigmentation of guinea pig skin

This study demonstrated the mechanisms of the inhibitory effects of GD against UVB-induced pigmentation in guinea pig skin.

A novel synthetic Piper amide derivative NED-180 inhibits hyperpigmentation by activating the PI3K and ERK pathways and by regulating Ca2+ influx via TRPM1 channels

Piper amides have a characteristic, unsaturated amide group and exhibit diverse biological activities, including proliferation and differentiation of melanocytes, although the molecular mechanisms underlying its antimelanogenesis effect remain unknown. We screened a selected chemical library of newly synthesized Piper amide derivatives and identified (E)-3-(4-(tert-butyl)phenyl)-N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylamide (NED-180) as one of the most potent compounds in suppressing melanogenesis. In murine melan-a melanocytes, NED-180 downregulated the expression of melanogenic regulatory proteins including tyrosinase, Tyrp1, Dct, and MITF. PI3K/Akt-dependent phosphorylation of GSK3β by NED-180 decreases MITF phosphorylation and inhibits melanogenesis without any effects on cytotoxicity and proliferation. Furthermore, topical application of NED-180 significantly ameliorated UVB-induced skin hyperpigmentation in guinea pigs. Interestingly, data obtained using calcium imaging techniques suggested that NED-180 reduced the TPA-induced activation of TRPM1 (melastatin), which could explain the NED-180-induced inhibition of melanogenesis. All things taken together, NED-180 triggers activation of multiple pathways, such as PI3K and ERK, and inhibits TRPM1/TRPV1, leading to inhibition of melanogenesis.

Extracts of Morus nigra L. Leaves Standardized in Chlorogenic Acid, Rutin and Isoquercitrin: Tyrosinase Inhibition and Cytotoxicity

Melanogenesis is a process responsible for melanin production, which is stored in melanocytes containing tyrosinase. Inhibition of this enzyme is a target in the cosmetics industry, since it controls undesirable skin conditions such as hyperpigmentation due to the overproduction of melanin. Species of the Morus genus are known for the beneficial uses offered in different parts of its plants, including tyrosinase inhibition. Thus, this project aimed to study the inhibitory activity of tyrosinase by extracts from Morus nigra leaves as well as the characterization of its chromatographic profile and cytotoxicity in order to become a new therapeutic option from a natural source. M. nigra leaves were collected, pulverized, equally divided into five batches and the standardized extract was obtained by passive maceration. There was no significant difference between batches for total solids content, yield and moisture content, which shows good reproducibility of the extraction process. Tyrosinase enzymatic activity was determined for each batch, providing the percentage of enzyme inhibition and IC₅₀ values obtained by constructing dose-response curves and compared to kojic acid, a well-known tyrosinase inhibitor. High inhibition of tyrosinase activity was observed (above 90% at 15.625 μg/mL). The obtained IC₅₀ values ranged from 5.00 μg/mL ± 0.23 to 8.49 μg/mL ± 0.59 and were compared to kojic acid (3.37 μg/mL ± 0.65). High Performance Liquid Chromatography analysis revealed the presence of chlorogenic acid, rutin and, its major compound, isoquercitrin. The chromatographic method employed was validated according to ICH guidelines and the extract was standardized using these polyphenols as markers. Cytotoxicity, assessed by MTT assay, was not observed on murine melanomas, human keratinocytes and mouse fibroblasts in tyrosinase IC₅₀ values. This study demonstrated the potential of M. nigra leaf extract as a promising whitening agent of natural source against skin hyperpigmentation.

Identifying Chinese herbal medicine network for treating acne: Implications from a nationwide database

ETHNO-PHARMACOLOGICAL RELEVANCE

Acne is a highly prevalent inflammatory skin disease which causes patients great psychological stress, especially teenagers. Chinese herbal medicine (CHM) is commonly used to treat acne with personalized but complicated prescriptions. The aim of this study is to determine a CHM network and core CHM treatments for acne by analyzing a nationwide database.

MATERIALS AND METHODS

From January 1st to December 31st, 2011, all CHM prescriptions made for acne (ICD-9-CM code: 706.0 or 706.1) were included in this study. Visits with acupuncture, manual therapy or other treatment modalities were excluded, and CHM visits with other diagnoses were also excluded in final analysis. Association rule mining (ARM) and social network analysis (SNA) were used to explore and demonstrate a CHM network.

RESULTS

A total of 91,129 patients used traditional Chinese medicine, and 99% of them chose CHM for acne treatment. Most CHM users were teenagers, and there were twice as many female patients as male patients. A total of 279,823 CHM prescriptions were made for acne in 2011. Qing-Shang-Fang-Feng-Tang was the most commonly used CHM (31.2% of all prescriptions), and Zhen-Ren-Huo-Ming-Yin combined with Forsythia suspensa (Thunb.) Vahl. (Lian Qiao) was the most commonly used CHM-CHM combination. Thirty-one important CHM-CHM combinations were identified, and the CHM network could be built. Extensive coverage of the known pathogenesis of acne could be found in the CHM network when incorporating CHM pharmacological mechanisms into the network. Anti-inflammatory and anti-bacterial effects were commonly found in the CHM network, and CHMs with anti-androgen, anti-depressive and skin whitening effects were frequently used in combination.

CONCLUSIONS

The CHM combination patterns and core treatments for acne were disclosed in this study by applying network analysis to a CHM prescription database. These results may be beneficial for further bench or clinical studies when choosing target CHM.

Enhanced Mulberroside A Production from Cell Suspension and Root Cultures of Morus alba Using Elicitation

Morus alba L. has been used in Asian traditional medicine as an anti-inflammatory, anti-asthmatic, anthelmintic and as a whitening agent in cosmetic products. Mulberroside A is the major active compound from M. alba root bark. In this study, cell suspension and root cultures of M. alba were established, and the effect of the elicitors on the enhancement of mulberroside A production in M. alba was investigated. The cell suspension and root cultures of M. alba were exposed to elicitors and then mulberroside A contents were determined by an indirect competitive ELISA method. High levels of mulberroside A were obtained by addition of 100 and 200 μM salicylic acid with 24 h exposure time in cell suspension cultures (37.9 ± 1.5 and 34.0 ± 4.7 mg/g dry wt., respectively). Furthermore, addition of yeast extract at 2 mg/mL with 24 h exposure time can significantly increase mulberroside A contents from both cell suspension (3.2-fold) and root cultures (6.6-fold). Mulberroside A contents from both cell suspension and root cultures after treatment with elicitors are similar or higher than those found in the intact root and root bark of several years old M. alba. These results indicate that mulberry tissue cultures using the elicitation method are interesting alternative sources for mulberroside A production.

Characterization of Melanogenesis Inhibitory Constituents of Morus alba Leaves and Optimization of Extraction Conditions Using Response Surface Methodology

Melanin is a natural pigment that plays an important role in the protection of skin, however, hyperpigmentation cause by excessive levels of melatonin is associated with several problems. Therefore, melanogenesis inhibitory natural products have been developed by the cosmetic industry as skin medications. The leaves of Morus alba (Moraceae) have been reported to inhibit melanogenesis, therefore, characterization of the melanogenesis inhibitory constituents of M. alba leaves was attempted in this study. Twenty compounds including eight benzofurans, 10 flavonoids, one stilbenoid and one chalcone were isolated from M. alba leaves and these phenolic constituents were shown to significantly inhibit tyrosinase activity and melanin content in B6F10 melanoma cells. To maximize the melanogenesis inhibitory activity and active phenolic contents, optimized M. alba leave extraction conditions were predicted using response surface methodology as a methanol concentration of 85.2%; an extraction temperature of 53.2 °C and an extraction time of 2 h. The tyrosinase inhibition and total phenolic content under optimal conditions were found to be 74.8% inhibition and 24.8 μg GAE/mg extract, which were well-matched with the predicted values of 75.0% inhibition and 23.8 μg GAE/mg extract. These results shall provide useful information about melanogenesis inhibitory constituents and optimized extracts from M. alba leaves as cosmetic therapeutics to reduce skin hyperpigmentation.

The natural yeast extract isolated by ethanol precipitation inhibits melanin synthesis by modulating tyrosinase activity and downregulating melanosome transfer

This study was conducted to examine the effects of EP-2, a natural yeast extract isolated by ethanol precipitation from Saccharomyces cerevisiae, on melanogenesis and to determine its underlying mechanism of action. Our results show that although EP-2 is not a direct tyrosinase inhibitor, when EP-2 was added to the culture media of B16F10 melanoma cells, intracellular tyrosinase activity was decreased. However, EP-2 had no effect on the expression of microphthalmia-associated transcription factor or tyrosinase. EP-2 was found to inhibit melanogenesis and melanosome transfer when it was added to melanocytes and keratinocytes in coculture. In addition, protease-activated receptor 2, a key protein associated with melanosome transfer from melanocytes to keratinocytes, was downregulated in the presence of EP-2. In conclusion, EP-2 is a potent inhibitor of melanogenesis and its hypomelanogenic effect is related to the inhibition of tyrosinase activity and transfer of melanosomes.

Antimelanogenic chemicals with in vivo efficacy against skin pigmentation in guinea pigs

Ultraviolet (UV) radiation under sunlight stimulates skin pigmentation through immediately affecting the oxidative modification of existing melanin pigments and the spatial redistribution of pigmented melanosomes followed by the up-regulation of melanogenic genes in delayed kinetics. However, abnormal accumulation and synthesis of melanin biopolymers are responsible for skin disorders with more pigmented patches. Chemical-based regulation of the hyperpigmented disorders has been a long-standing goal for cosmetic and pharmaceutical applications. A large number of the chemicals with antimelanogenic activity have met with limited or no success in the treatment of skin patients, since they may not overcome the challenge of penetrating the skin barrier. Guinea pig skin displays similar kinetic parameters to human skin in the transdermal absorption of numerous chemicals, thus can serve as the surrogate for human skin. Here, we provide a concise review of our current understanding of the chemical-based therapy against skin hyperpigmentation in UV-irradiated guinea pig models, suggest molecular mechanisms of the action and emphasize the translation from preclinical outcomes to skin patients.

Octaphlorethol A isolated from Ishige foliacea inhibits α-MSH-stimulated induced melanogenesis via ERK pathway in B16F10 melanoma cells

In this study, the potent skin-whitening effects of Octaphlorethol A (OPA) isolated from Ishige foliacea was investigated through inhibitory effect of melanin synthesis and tyrosinase activity in alpha-melanocyte stimulating hormone (α-MSH) induced B16F10 melanoma cells. OPA markedly inhibited melanin synthesis and tyrosinase activity in a concentration-dependent manner. We also found that OPA decreased microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 and -2 (TRP-1 and TRP-2) protein expressions. Moreover, OPA reduces p38 MAPK protein levels and activates extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinases (JNKs) protein expressions in B16F10 cells. A specific ERK inhibitor PD98059 significantly blocks OPA-inhibited melanin synthesis and tyrosinase activity, whereas a p38MAP and JNK inhibitor had no effect. These findings provide evidence demonstrating that the anti-melanogenic effect of OPA is mediated through the activation of ERK signal pathway in B16F10 cells. These results indicate that OPA has the potential to be used as a melanogenesis inhibitor in the food and cosmetics industry.

Inhibitory effects of Cyrtomium fortunei J. Smith root extract on melanogenesis

Background:

Recently, a great deal of attention has been directed toward the use of crude extracts from natural products for cosmetic applications. Thus, we performed a series of experiments to investigate skin depigmenting properties of a crude extract that was derived from a traditional Korean medicinal plant.

Materials and Methods:

In this study, the depigmentational potency of Cyrtomium fortunei J. Smith was investigated. The inhibitory effects of the root of Cyrtomium fortunei J. Smith extract on melanin production were evaluated by assessing its tyrosinase inhibitory effects, melanin production-inhibitory properties in melan-a cells and depigmenting ability in brown guinea pig skin.

Results:

The methanolic extract of the root of Cyrtomium fortunei J. Smith appeared to inhibit tyrosinase activity and melanin production in melan-a cells. In addition, this extract exhibited depigmenting ability on Ultra violet-induced hyper pigmentation in brown guinea pig skin.

Conclusion:

These results suggested that root of Cyrtomium fortunei J. Smith might prove useful in treating skin hyperpigmentation associated with excess sun-exposure.

In vitro and in vivo studies disclosed the depigmenting effects of gallic acid: a novel skin lightening agent for hyperpigmentary skin diseases

Gallic acid (GA) is a phenolic compound, which has been reported to suppress melanogenesis in melanoma cells. However, the molecular mechanism underlying this inhibitory effect was poorly understood. In this article, we revealed that GA down-regulated melanogenic regulatory genes including tyrosinase, tyrosinase related protein-1 (TRP-1), and dopachrome tatamerase (Dct) expression at transcriptional and translational level. In addition, GA effectively suppressed the microphthalmia-associated transcription factor (MITF) expression by down-regulating the cAMP-mediated PKA/CREB signaling cascades. To delineate the inhibition of MITF by GA, the activation of extracellular signal-regulated protein kinase (ERK) and AKT was investigated. GA caused significant increase of ERK and AKT phosphorylation, while ERK (PD98059) or AKT (LY294002) inhibitor prevents their phosphorylation and increased melanin biosynthesis. In addition, pre-treatment of MITF-siRNA significantly reduced melanin production from 100 to 40%, and even decreased into 10% by combination treatment with GA. Furthermore, UVB-induced hyperpigmentation in the mice skin was significantly rescued by topical application of GA for 4 weeks. Immunohistochemical analyses also confirmed that GA significantly inhibited melanin production followed by the down-regulation of MITF, tyrosinase and their regulatory proteins. In addition, when compared with control zebrafish, GA caused a remarkable inhibition on the endogenous pigmentation in the zebrafish. Results presented in this study strongly suggest that GA is an effective de-pigmenting or skin lightening cosmetics for topical application.

Isolation of resveratrol from vitis viniferae caulis and its potent inhibition of human tyrosinase

Tyrosinase (TYR) catalyzes rate-limiting reactions of cellular melanin synthesis, and its inhibitors are of commercial interest as potential skin whitening agents. However, the limited availability of human TYR makes the screening of TYR inhibitors difficult. To overcome this hurdle, we transformed nonmelanocytic human embryonic kidney (HEK) 293 cells to express human TYR constitutively. Using these cells as a source of human TYR, the ethanolic extracts of 52 medicinal plants grown in Korea were tested for human TYR activity, and the extract of Vitis Viniferae Caulis (dried stems of the grape tree, Vitis vinifera L.) was found to inhibit human TYR activity potently. An active compound was isolated from this extract by solvent fractionation followed by liquid column chromatography and identified as resveratrol by spectroscopic and chromatographic analyses. Resveratrol was determined to be a highly potent inhibitor of human TYR (IC50 = 0.39 μg mL⁻¹) as compared with p-coumaric acid (IC50 = 0.66 μg mL⁻¹) and arbutin (IC50 > 100 μg mL⁻¹) and inhibited melanin synthesis by human epidermal melanocytes at subtoxic concentrations. This study suggests that resveratrol and resveratrol-containing extracts of Vitis Viniferae Caulis have a potential use as skin whitening agents.

Skin ageing: natural weapons and strategies

The fact that the skin is the most visible organ makes us aware of the ageing process every minute. The use of plant extracts and herbs has its origins in ancient times. Chronological and photo-ageing can be easily distinguished clinically, but they share important molecular features. We tried to gather the most interesting evidence based on facts about plants and plant extracts used in antiaging products. Our main idea was to emphasize action mechanisms of these plant/herbal products, that is, their “strategies” in fighting skin ageing. Some of the plant extracts have the ability to scavenge free radicals, to protect the skin matrix through the inhibition of enzymatic degradation, or to promote collagen synthesis in the skin. There are some plants that can affect skin elasticity and tightness. Certainly, there is a place for herbal principles in antiaging cosmetics. On the other hand, there is a constant need for more evaluation and more clinical studies in vivo with emphasis on the ingredient concentration of the plant/herbal products, its formulation, safety, and duration of the antiaging effect.

Natural Melanogenesis Inhibitors Acting Through the Down-Regulation of Tyrosinase Activity

Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis, and the down-regulation of enzyme activity is the most reported method for the inhibition of melanogenesis. Because of the cosmetically important issue of hyperpigmentation, there is a big demand for melanogenesis inhibitors. This encourages researchers to seek potent melanogenesis inhibitors for cosmetic uses. This article reviews melanogenesis inhibitors that have been recently discovered from natural sources. The reaction mechanisms of the inhibitors on tyrosinase activity are also discussed.

Combining poly-arginine with the hydrophobic counter-anion 4-(1-pyrenyl)-butyric acid for protein transduction in transdermal delivery

Topical therapy is the most favored form of treatment for whitening against hyperpigmentation and sunburn because it lends itself to self-administration, patient compliance, and absence of systemic adverse effects. However, transdermal delivery of hydrophilic chemicals is difficult. The main purpose of this study is to develop a delivering system of hydrophilic drugs and proteins across the skin. Hydroquinone (HQ), a well-known tyrosinase inhibitor and antimelanogenesis compound, and enhanced green fluorescent protein (EGFP) were fused with eleven poly-arginine (11R). Both HQ-11R and EGFP-11R were efficiently delivered in B16 cells, a mouse melanoma cell line. HQ-11R was as effective as HQ alone at inhibiting melanin synthesis in B16 cells. EGFP-11R was efficiently delivered into cells of the epidermis with 4-(1-pyrenyl)-butyric acid (PB), a counteranion bearing an aromatic hydrophobic moiety, in vivo, but EGFP alone or EGFP-11R without PB was not. Finally, topical application of HQ-11R with PB significantly inhibited UV irradiation-induced pigmentation in guinea pigs compared with HQ alone. These results suggest that topical therapy using poly-arginine in combination with PB is useful for the delivery of hydrophilic drugs and proteins by the transdermal route.