Bifunctional effects of O-methylated flavones from Scutellaria baicalensis Georgi on melanocytes: Inhibition of melanin production and intracellular melanosome transport

Expert consensus on perioperative integrated skincare for noninvasive energy-based device aesthetic procedures in clinical practice in China

BACKGROUND

Noninvasive energy-based device (NI-EBD) aesthetic procedures has recently gained widespread usage for treating various skin conditions, enhancing skin texture and performing rejuvenation-related procedures. However, practically all NI-EBD procedures result in variable degrees of damage to the skin barrier, inducing pathological and physiological processes such as oxidative stress and inflammation, and only a small percentage of individuals possess the innate ability to restore it.

OBJECTIVE

To introduce the concept of integrated skincare and establish standardized operational procedures for perioperative integrated skincare, and furnish a theoretical basis for clinical diagnosis and treatment performed by professional medical aestheticians.

METHODS

The author leveraged domestic and international guidelines, clinical practice expertise and evidence-based research, adapting them to suit the specific circumstances in China.

RESULTS

The consensus were provided four parts, including concept and essence of integrated skincare, integrated skincare significance during the perioperative phase of NI-EBD procedures, active ingredients and functions of effective skincare products, standardized perioperative skincare procedure for NI-EBD procedures and precautions. For the standardized perioperative skincare procedure, four recommendations were listed according to different stages during NI-EBD procedures.

CONCLUSION

These recommendations create the 'Expert Consensus on Perioperative Integrated Skincare for Noninvasive Energy-Based Device Aesthetic Procedures in Clinical Practice in China'.

Anti-melanogenic effect of exosomes derived from human dermal fibroblasts (BJ-5ta-Ex) in C57BL/6 mice and B16F10 melanoma cells

Exosomes are involved in intercellular communication by transferring cargo between cells and altering the specific functions of the target cells. Recent studies have demonstrated the therapeutic effects of exosomes in several skin diseases. However, understanding of the effects of exosomes on anti-pigmentation is limited. Therefore, we investigated whether BJ-5ta exosomes (BJ-5ta-Ex) derived from human foreskin fibroblasts regulate melanogenesis and delineated the underlying mechanism. Interestingly, treatment with BJ-5ta-Ex induced decreased melanin content, tyrosinase (TYR) activity, and expression of melanogenesis-related genes, including microphthalmia-related transcription factor (MITF), TYR, tyrosinase-related protein-1 (TRP1), and tyrosinase-related protein-2 (TRP2). In addition, BJ-5ta-Ex downregulated the cAMP/PKA and GSK-3β/β-catenin signaling pathways and upregulated the MAPK/ERK signaling pathway. Notably, treatment with BJ-5ta-Ex inhibited α-melanocyte-stimulating hormone-induced melanosome transport and decreased the expression of key proteins involved in melanosome transport, namely, rab27a and melanophilin (MLPH). To further confirm the depigmenting effects of BJ-5ta-Ex, we conducted experiments using a three-dimensional reconstituted human full skin model and ultraviolet B (UVB)-irradiated mouse model. Treatment with BJ-5ta-Ex improved tissue brightness and reduced the distribution of melanosomes. In UVB-irradiated mouse ears, BJ-5ta-Ex reduced the number of active melanocytes and melanin granules. These results demonstrate that BJ-5ta-Ex can be useful for the clinical treatment of hyperpigmentation disorders.

Oroxylin A ameliorates ultraviolet radiation-induced premature skin aging by regulating oxidative stress via the Sirt1 pathway

Skin is susceptible to premature aging in response to ultraviolet (UV) radiation-induced oxidative stress, which can ultimately result in aberrant aging or age-related disorders. Accordingly, strategies that can be adopted to mitigate oxidative stress may contribute to protecting skin from induced aging-related damage, thereby offering promising approaches for the treatment of skin diseases and disorders. In this regard, oroxylin A (OA), a natural flavonoid isolated from certain plants used in traditional Chinese medicine, is considered to have notable antioxidant, anti-inflammatory, and anti-apoptotic properties, and is often used to treat certain inflammatory diseases. To date, however, there has been comparatively little research on the effects of OA with respect skin aging. In this study, we utilized UV radiation-induced mouse and cellular models of aging to assess the efficacy of OA in protecting against skin aging. Subsequently, to elucidate the potential mechanisms underlying the protective effect of OA on skin aging, we performed molecular docking analysis to investigate the involvement of the anti-aging gene Sirt1, which was further confirmed on the basis of Sirt1 gene silencing. We accordingly demonstrated that by promoting an increase in the expression of Sirt1, OA can contribute to suppressing UV-induced skin photo-aging in cells/mice by reducing oxidative stress. Furthermore, we established that by activating Sirt1, OA can also promote the dissociation of Nrf2 from Keap1 and its subsequent nuclear translocation. Collectively, our findings in this study reveal OA to be an effective natural compound that can be administered to delay the aging of skin triggered by UV, both in vivo and in vitro, by binding to Sirt1 to promote the deacetylation and nuclear translocation of Nrf2, thereby contributing to a reduction in oxidative stress. These findings may this provide a therapeutic target for the prevention of skin aging or aging-induced skin diseases.

Bibliometric Study of Adaptogens in Dermatology: Pharmacophylogeny, Phytochemistry, and Pharmacological Mechanisms

Background

Adaptogens are a class of medicinal plants that can nonspecifically enhance human resistance. Most of the plant adaptogens have relevant applications in dermatology, but there are still few studies related to their particular action and co-operative mechanisms in topical skin application.

Methods

Plant adaptogens related articles and reviews that published between 1999 and 2022 were obtained from the Web of Science Core Collection database. Various bibliographic elements were collected, including the annual number of publications, countries/regions, and keywords. CiteSpace, a scientometric software, was used to conduct bibliometric analyses. Also, the patsnap global patent database was used to analyze the patent situation of plant adaptogens in the field of cosmetics up to 2021.

Results

We found that the effects of plant adaptogens on skin diseases mainly involve atopic dermatitis, acne, allergic contact dermatitis, psoriasis, eczema, and androgenetic alopecia, etc. And the effects on skin health mainly involve anti-aging and anti-photoaging, anti-bacterial and anti-fungal, anti-inflammatory, whitening, and anti-hair loss, etc. Also, based on the results of patent analysis, it is found that the effects of plant adaptogens on skin mainly focus on aging retardation. The dermatological effects of plant adaptogens are mainly from Fabaceae Lindl., Araliaceae Juss. and Lamiaceae Martinov., and their mainly efficacy phytochemical components are terpenoids, phenolic compounds and flavonoids.

Conclusion

The plant adaptogens can repair the skin barrier and maintain skin homeostasis by regulating the skin HPA-like axis, influencing the oxidative stress pathway to inhibit inflammation, and regulating the extracellular matrix (ECM) components to maintain a dynamic equilibrium, ultimately achieving the treatment of skin diseases and the maintenance of a healthy state.

Anti-cancer, Anti-collagenase and Anti-elastase Potentials of Some Natural Derivatives: In vitro and in silico Studies

The anti-cancer activities of the compounds were evaluated against KYSE-150, KYSE-30, and KYSE-270 cell lines and also on investigated esophageal line HET 1 A as a standard. Modified inhibitory impact on enzymes of collagenase and elastase were used Thring and Moon methods, respectively. Among both compounds, both of them recorded impact on cancer cells being neutral against the control, both had IC50 lower than 100 µM and acted as a potential anticancer drug. The chemical activities of Skullcapflavone I and Skullcapflavone II against elastase and collagenase were investigated utilizing the molecular modeling study. IC50 values of Skullcapflavone I and Skullcapflavone II on collagenase enzyme were obtained 106.74 and 92.04 µM and for elastase enzyme were 186.70 and 123.52 µM, respectively. Anticancer effects of these compounds on KYSE 150, KYSE 30, and KYSE 270 esophageal cancer cell lines studied in this work. For Skullcapflavone I, IC50 values for these cell lines were obtained 14.25, 19.03, 25.10 µM, respectively. Also, for Skullcapflavone II were recorded 20.42, 34.17, 22.40 µM, respectively. The chemical activities of Skullcapflavone I and Skullcapflavone II against some of the expressed surface receptor proteins (CD44, EGFR, and PPARγ) in the mentioned cell lines were assessed using the molecular docking calculations. The calculations showed the possible interactions and their characteristics at an atomic level.

Advances in Biomedical Functions of Natural Whitening Substances in the Treatment of Skin Pigmentation Diseases

Pigmentation diseases can lead to significant color differences between the affected part and the normal part, resulting in severe psychological and emotional distress among patients. The treatment of pigmentation diseases with good patient compliance is mainly in the form of topical drugs. However, conventional hydroquinone therapy contributes to several pathological conditions, such as erythema, dryness, and skin desquamation, and requires a longer treatment time to show significant results. To address these shortcomings, natural whitening substances represented by kojic acid and arbutin have gradually become the candidate ingredients of traditional local preparations due to their excellent biological safety. This review focuses on several natural whitening substances with potential therapeutic effects in pigmentation disease and their mechanisms, and a thorough discussion has been conducted into the solution methods for the challenges involved in the practical application of natural whitening substances.

Silencing of Rab23 by siRNA inhibits ultraviolet B-induced melanogenesis via downregulation of PKA/CREB/MITF

Recent investigations have shown that the Rab family of GTPases is associated with all aspects of melanogenesis. However, the effect of Rab23, which localizes to the plasma membrane and regulates the endocytic pathway within eukaryotic cells, in melanogenesis has not been reported. To understand the role of Rab23 in UVB-induced melanogenesis, we evaluated changes in the level of melanin, activity of tyrosinase, and levels of melanogenesis-related proteins such as microphthalmia transcription factor and tyrosinase-related protein-1 (TRP-1) and the melanosome transport-related protein complex Rab27a-melanophilin-myosin Va after the downregulation of Rab23 in B16F10 and SK-MEL-2 cells with or without UVB irradiation. Our results showed that downregulating Rab23 reduced the melanin level and tyrosinase activity and inhibited the expression of proteins involved in UVB-induced melanogenesis. Rab23 colocalized with mature melanosomes marked with TRP-1. Furthermore, downregulating Rab23 induced the abnormal accumulation of melanosomes around the nucleus. We demonstrated that the downregulation of Rab23 inhibited melanin synthesis and melanosome transport by decreasing the PKA/CREB/MITF pathway, which is the key regulator of UVB-induced melanogenesis.

Rhamnazin suppresses melanosome transport by promoting the ubiquitin-mediated proteasomal degradation of melanophilin

BACKGROUND

Melanosomes are intracellularly transported from the perinuclear region to the cell periphery and then to neighboring keratinocytes. We recently reported that the flavonoid rhamnazin suppresses melanosomal transport within pigment cells, yet the action mechanism remained unclear.

OBJECTIVE

Our aim was to elucidate how rhamnazin influences the intracellular transport of melanosomes.

METHODS

A melanosome distribution assay and immunostaining were performed using B16F10 mouse melanoma cells and normal human epidermal melanocytes, respectively. Expression levels of melanosome transport-related proteins, including melanophilin (MLPH), RAB27A, and myosin VA (MYO5A), were analyzed by immunoblotting. Ubiquitinated MLPH was detected using a commercial ubiquitin detection kit. To investigate the interaction between rhamnazin and MLPH, we prepared rhamnazin conjugated with magnetic FG beads.

RESULTS

Immunoblotting analysis revealed that rhamnazin specifically reduces the expression of MLPH but not RAB27A or MYO5A proteins. The ubiquitin detection assay, which made use of a proteasome inhibitor, showed that MLPH accumulated as a polyubiquitinated protein after treatment with rhamnazin. We speculated that the affinity of rhamnazin for the components of the melanosome transport-related tripartite complex may alter the stability of the formation of the tripartite assembly. By using affinity-based techniques with B16F10 whole cell lysates or recombinant MLPH and RAB27A proteins, we revealed the interaction of rhamnazin with the components of the tripartite complex.

CONCLUSION

We found that rhamnazin inhibits intracellular transport of melanosomes through proteasomal degradation of MLPH. Our results suggest that topical application of rhamnazin may provide a new approach for treating skin pigmentation disorders.

Natural products are an important source for proteasome regulating agents

BACKGROUND

Natural medicines have a long history in the prevention and treatment of various diseases in East Asian region, especially in China. Modern research has proved that the pharmacological effects of numerous natural medicines involve the participation of ubiquitin proteasome system (UPS). UPS can degrade the unwanted and damaged proteins widely distributed in the nucleus and cytoplasm of various eukaryotes.

PURPOSE

The objective of the present study was to review and discuss the regulatory effects of natural products and extracts on proteasome components, which may help to find new proteasome regulators for drug development and clinical applications.

METHODS

The related information was compiled using the major scientific databases, such as CNKI, Elsevier, ScienceDirect, PubMed, SpringerLink, Wiley Online, and GeenMedical. The keywords "natural product" and "proteasome" were applied to extract the literature. Nature derived extracts, compounds and their derivatives involved in proteasome regulation were included, and the publications related to synthetic proteasome agents were excluded.

RESULTS

The pharmacological effects of more than 80 natural products and extracts derived from phytomedicines related to the proteasome regulation were reviewed. These natural products were classified according to their chemical properties. We also summarized some laws of action of natural products as proteasome regulators in the treatment of diseases, and listed the action characteristics of the typical natural products.

CONCLUSION

Natural products derived from nature can induce the degradation of damaged proteins through UPS or act as regulators to directly regulate the activity of proteasome. But few proteasome modulators are applied clinically. Summary of known rules for proteasome modulators will contribute to discover, modify and synthesize more proteasome modulators for clinical applications.

Salicylic acid in ginseng root alleviates skin hyperpigmentation disorders by inhibiting melanogenesis and melanosome transport

Abnormal melanogenesis and melanosome transport can cause skin pigmentation disorders that are often treated using ginseng-based formulation. We previously found that phenolic acid compounds in ginseng root could inhibit melanin production and as a skin-whitening agents. However, mechanisms of action underlying effects of ginseng phenolic acid monomers on melanogenesis remain unclear. This study was conducted to investigate effects of salicylic acid, a main ginseng root phenolic acid component, on melanogenesis and melanosome functions in melanocytes of zebrafish and other species. Salicylic acid exhibited no cytotoxicity and reduced melanin levels and tyrosinase activity in B16F10 murine melanoma cells and normal human epidermal melanocytes regardless of prior cell stimulation with α-melanocyte stimulating hormone. Additionally, salicylic acid treatment reduced expression of melanogenic enzymes tyrosinase, tyrosinase-related protein 1 and tyrosinase-related protein 2, while reducing expression of their master transcriptional regulator, microphthalmia-associated transcription factor. Moreover, reduced phosphorylation of cAMP response-element binding protein was observed due to reduced cAMP levels resulting from salicylic acid inhibition of upstream signal regulators (adenylyl cyclase and protein kinase A). Furthermore, salicylic acid treatment suppressed expression of transport complex-associated proteins melanophilin and myosin Va in two UVB-treated melanocytic cell lines, suppressed phagocytosis of fluorescent microspheres by UVB-stimulated human keratinocytes (HaCaT), inhibited protease-activated receptor 2 activation by reducing both Ca²⁺ release and activation of phosphoinositide 3 kinase/AKT and mitogen-activated protein kinases and induced anti-melanogenic effects in zebrafish. Collectively, these results indicate that salicylic acid within ginseng root can inhibit melanocyte melanogenesis and melanin transport, while also suppressing keratinocyte phagocytic function.

Transdermal Delivery Systems of Natural Products Applied to Skin Therapy and Care

Natural products are favored because of their non-toxicity, low irritants, and market reacceptance. We collected examples, according to ancient wisdom, of natural products to be applied in transdermal delivery. A transdermal delivery system, including different types of agents, such as ointments, patches, and gels, has long been used for skin concerns. In recent years, many novel transdermal applications, such as nanoemulsions, liposomes, lipid nanoparticles, and microneedles, have been reported. Nanosized drug delivery systems are widely applied in natural product deliveries. Nanosized materials notably enhance bioavailability and solubility, and are reported to improve the transdermal permeation of many substances compared with conventional topical formulations. Natural products have been made into nanosized biomaterials in order to enhance the penetration effect. Before introducing the novel transdermal applications of natural products, we present traditional methods within this article. The descriptions of novel transdermal applications are classified into three parts: liposomes, emulsions, and lipid nanoparticles. Each section describes cases that are related to promising natural product transdermal use. Finally, we summarize the outcomes of various studies on novel transdermal agents applied to skin treatments.

CMT-308, a Nonantimicrobial Chemically-Modified Tetracycline, Exhibits Anti-Melanogenic Activity by Suppression of Melanosome Export

CMT-308 is a nonantimicrobial chemically-modified tetracycline (CMT), which we have previously shown exhibits antifungal activity and pleiotropic anti-inflammatory activities, including inhibition of the enzymatic activity of matrix metalloproteinases (MMPs). Based on its chemical structure, we hypothesized that CMT-308 could inhibit melanogenesis and might be a candidate for the treatment of skin hyperpigmentation disorders which occur due to unregulated melanin biosynthesis and/or transport. CMT-308 was first studied for any effects on activity of the enzyme tyrosinase in vitro using a purified preparation of mushroom tyrosinase; the mode of inhibition of the soluble fungal enzyme was evaluated by Lineweaver-Burk and Dixon plots as well as by non-linear least squares fitting. Next, the effects of CMT-308 were tested in mammalian cell cultures using B16F10 mouse melanoma cells and further validated in darkly-pigmented human melanocytes (HEMn-DP). Our results showed that micromolar concentrations of CMT-308 inhibited mushroom tyrosinase enzyme activity, using the first two substrates in the melanogenesis pathway (l-tyrosine and l-3,4-dihydroxyphenylalanine (l-DOPA)); CMT-308 inhibited mushroom tyrosinase primarily via a mixed mode of inhibition, with the major contribution from a competitive mode. In B16F10 cell cultures, CMT-308 (10 µM) significantly diminished total melanin levels with a selective reduction of extracellular melanin levels, under both basal and hormone-stimulated conditions without any cytotoxicity over a duration of 72 h. Studies of potential mechanisms of inhibition of melanogenesis in B16F10 cells showed that, in mammalian cells, CMT-308 did not inhibit intracellular tyrosinase activity or the activity of α-glucosidase, an enzyme that regulates maturation of tyrosinase. However, CMT-308 suppressed MITF protein expression in B16F10 cells and showed copper chelating activity and antioxidant activity in a cell-free system. The significantly lower extracellular melanin levels obtained at 10 µM indicate that CMT-308’s anti-melanogenic action may be attributed to a selective inhibition of melanosome export with the perinuclear aggregation of melanosomes, rather than a direct effect on the tyrosinase-catalyzed steps in melanin biosynthesis. These results were validated in HEMn-DP cells where CMT-308 suppressed dendricity in a fully reversible manner without affecting intracellular melanin synthesis. Furthermore, the capacity of CMT-308 to inhibit melanosome export was retained in cocultures of HEMn-DP and HaCaT. In summary, our results offer promise for therapeutic strategies to combat the effects of hyperpigmentation by use of CMT-308 at low micromolar concentrations.

Applications, phytochemistry, pharmacological effects, pharmacokinetics, toxicity of Scutellaria baicalensis Georgi. and its probably potential therapeutic effects on COVID-19: a review

Scutellaria baicalensis Georgi. (SB) is a common heat-clearing medicine in traditional Chinese medicine (TCM). It has been used for thousands of years in China and its neighboring countries. Clinically, it is mostly used to treat diseases such as cold and cough. SB has different harvesting periods and processed products for different clinical symptoms. Botanical researches proved that SB included in the Chinese Pharmacopoeia (1st, 2020) was consistent with the medicinal SB described in ancient books. Modern phytochemical analysis had found that SB contains hundreds of active ingredients, of which flavonoids are its major components. These chemical components are the material basis for SB to exert pharmacological effects. Pharmacological studies had shown that SB has a wide range of pharmacological activities such as antiinflammatory, antibacterial, antiviral, anticancer, liver protection, etc. The active ingredients of SB were mostly distributed in liver and kidney, and couldn't be absorbed into brain via oral absorption. SB's toxicity was mostly manifested in liver fibrosis and allergic reactions, mainly caused by baicalin. The non-medicinal application prospects of SB were broad, such as antibacterial plastics, UV-resistant silk, animal feed, etc. In response to the Coronavirus Disease In 2019 (COVID-19), based on the network pharmacology research, SB's active ingredients may have potential therapeutic effects, such as baicalin and baicalein. Therefore, the exact therapeutic effects are still need to be determined in clinical trials. SB has been reviewed in the past 2 years, but the content of these articles were not comprehensive and accurate. In view of the above, we made a comprehensive overview of the research progress of SB, and expect to provide ideas for the follow-up study of SB.

Small interfering RNA target for long noncoding RNA PCGEM1 increases the sensitivity of LNCaP cells to baicalein

The objective of this study is to investigate the inhibitory effect and mechanism of long noncoding RNA PCGEM1 siRNA combined with baicalein on prostate cancer LNCaP cells. LNCaP cells transfected with small hairpin RNA lentiviral vector targeting PCGEM1 were constructed and their expression in LNCaP cells was absent. The stable cell line of LNCaP cells infected with LV3-shRNA-PCGEM1 was successfully constructed. In addition, LV3-shRNA-PCGEM1 was able to increase the baicalein-induced inhibitory effects on LNCaP cells, and the susceptibility was 2.3 fold higher than that of baicalein alone. LV3-shRNA-PCGEM1 combined with baicalein also inhibited the colony formation, increased G2 and S phase cells, inhibited the expression of PCGEM1, and induced autophagy of LNCaP cells. In summary, LV3-shRNA-PCGEM1 may improve the sensitivity of LNCaP cells to baicalein, and the molecular mechanism may be associated with the decrease of PCGEM1 expression and the induction of autophagy. Our findings provided an experimental basis for the combined treatment of Chinese traditional and Western medicine on prostate cancer in a clinical setting.

Natural skin-whitening compounds for the treatment of melanogenesis (Review)

Melanogenesis is the process for the production of melanin, which is the primary cause of human skin pigmentation. Skin-whitening agents are commercially available for those who wish to have a lighter skin complexions. To date, although numerous natural compounds have been proposed to alleviate hyperpigmentation, insufficient attention has been focused on potential natural skin-whitening agents and their mechanism of action from the perspective of compound classification. In the present article, the synthetic process of melanogenesis and associated core signaling pathways are summarized. An overview of the list of natural skin-lightening agents, along with their compound classifications, is also presented, where their efficacy based on their respective mechanisms of action on melanogenesis is discussed.

Traditional Chinese Herbal Medicine for Whitening

Melanin is the chief pigment responsible for the pigmentation of human skin. Increasing evidence indicates that traditional Chinese drugs with skin-whitening effects are attracting the attention of consumers and researchers because they are perceived to be milder, safer, and healthier than synthetic alternatives. This commentary summarizes the current research on Chinese herbal medicines that inhibit melanin and their biological activities. The findings presented in this study suggest that these traditional Chinese herbal medicines might be potential candidates for novel skin-whitening agents.

Optimization of Ultrasonic Flavonoid Extraction from Saussurea involucrate, and the Ability of Flavonoids to Block Melanin Deposition in Human Melanocytes

(1) Background: Flavonoids are the primary medicinal ingredient of Saussurea involucrate, which have significant antioxidant capacity. Optimizing the extraction of Saussurea involucrate flavonoids (SIFs) and exploring the ability to block melanin deposition caused by reactive oxygen can greatly promote the development of S. involucrate whitening products. (2) Methods: Ultrasonic extraction process was optimized using the Box-Behnken design (BBD) and response surface methodology (RSM). Then, the effect of SIFs on antioxidant activity and anti-deposition of melanin, and genes related to the melanin synthesis are studied. (3) Results: The optimal extraction procedures are as follows: the extraction time, ethanol content, and solvent ratio (v/w) are 64 min, 54%, and 54:1, respectively. The reducing activity and scavenging rates of 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, hydroxyl radical, and ABTS⁺ were promoted as more S. involucrate flavonoid extract was added. The SIFs extract induced a decrease in the melanin synthesis by inhibiting the human melanoma A375 cell tyrosinase activity. SIFs also depress expression of melanin synthesis related genes. (4) Conclusions: the highest SIFs content was obtained by using 54% ethanol and 54:1 solvent ratio (v/w) for 64 min. The extract of SIFs exhibited good ability of antioxidant and anti-deposition of melanin in human melanocytes.

The role and mechanism of Asian medicinal plants in treating skin pigmentary disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Chloasma, senile plaques, vitiligo and other pigmentary disorders seriously affect patients' appearance and life quality. Medicinal plant is the product of long-term medical practice worldwide, with the advantages of outstanding curative properties and less side effects. Recently, research were made to explore the value of medicinal plants in the treatment of pigmentary disorders, and remarkable results were achieved.

AIM OF THE REVIEW

This review outlines the current understanding of the role and potential mechanisms of medicinal plants (including active ingredients, extracts and prescriptions) in pigmentary disorders, especially Chinese medicinal plants, provides the preclinical evidence for the clinical benefits. This study hopes to provide comprehensive information and reliable basis for exploring new therapeutic strategies of plant drugs in the treatment of skin pigmented diseases.

METHODS

The literature information was obtained from the scientific databases (up to Oct, 2017), mainly from the PubMed, Web of Science and CNKI databases, and was to identify the experimental studies on the regulating melanogenesis role of the active agents from herbal medicine and the involved mechanisms. The search keywords for such work included: "pigmentary" or "pigmentation", "melanogenesis", and "traditional Chinese medicine" or "Chinese herbal medicine", "herb", "medicinal plant".

RESULTS

We summarized the function of medicinal plants involved in melanogenesis, especially Chinese medicine. It was reported that the active ingredients, extracts, or prescriptions of medicinal plants can regulate the expression of genes related to melanogenesis by affecting the signaling pathways such as MAPK and PKA, thereby regulating pigment synthesis. Some of them can promote melanogenesis (such as isoliquiritigenin, geniposide; Cornus officinalis Siebold & Zucc., Eclipta prostrata (L.) L.; the Bairesi complex prescription, etc.). While others have the opposite effect (such as biochanin A, Gomisin N; Panax ginseng C.A. Meyer, Nardostachys chinensis Bat.; Sanbaitang, etc.).

CONCLUSION

Asian medicinal plants, especially their active ingredients, have multilevel effects on melanogenesis by regulating melanogenesis-related genes or signaling pathways. They are of great clinical value for the treatment of skin pigmentary disorders. However, the experimental effect, safety, and functional mechanism of the medicinal plants require further determination before studying their clinical efficacy.

Scutellaria baicalensis Georgi. (Lamiaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology

OBJECTIVES

Scutellaria baicalensis Georgi. (Lamiaceae) is a plant of the genus Lamiaceae, and its root is the main part used as a medicine. In China, Scutellaria baicalensis is still an important traditional Chinese medicine with the functions of clearing away heat and dampness, purging fire and detoxification. This medicinal plant is widely distributed in China, Russia, Mongolia, North Korea and Japan. The purpose of this paper was to provide a systematic and comprehensive overview on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics and toxicology of this plant. Furthermore, the possible development trends and perspectives for future research on this medicinal plant are also discussed.

KEY FINDINGS

So far, over 40 compounds have been isolated and identified from Scutellaria baicalensis, including flavonoids, terpenoids, volatile oils and polysaccharides. The compounds and extracts isolated from Scutellaria baicalensis exhibit a wide range of pharmacological activities, including the effects on the nervous system, effects on the immune system, liver protection, antitumour effects, antibacterial and antiviral effects, antioxidant effects and other pharmacological effects.

SUMMARY

As a traditional Chinese herbal medicine, Scutellaria baicalensis has shown significant effects on the treatment of various diseases, especially hepatitis, diarrhoea, vomiting and high blood pressure. Numerous traditional uses of Scutellaria baicalensis have been confirmed by current investigations. However, it is also necessary to further study the drug-forming properties and pharmacokinetics of the active constituents of Scutellaria baicalensis, as well as to establish quality control standards for different areas of Scutellaria baicalensis, and to carry out the research at the cellular and molecular levels.