Inhibition of melanogenesis by piceid isolated from Polygonum cuspidatum

Network pharmacology and experimental validation reveals the potential therapeutic effects of Polygonum cuspidatum against odontogenic keratocyst

This study aimed to explore active ingredients in Polygonum cuspidatum with potential effects on odontogenic keratocysts (OKCs) using network pharmacological approach and bioinformatic gene analysis. The active ingredients and targets of P. cuspidatum were selected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, and the ingredient-target network was constructed using Cytoscape software. Differentially expressed genes (DEGs) of OKC were selected and Gene Ontology (GO) enrichment analysis were performed through bioinformatic analysis using Gene Expression Omnibus (GEO) dataset GSE38494. The STRING database platform was used to draw protein-protein interaction network diagram, then the hub gene analysis was performed by Cytoscape software. AutoDock Vina software was used to perform molecular docking verification of the effects of the active ingredients on potential core targets. Finally, we use OKC nude animal model to testify the potential effects of P. cuspidatum. Ten active ingredients of P. cuspidatum were obtained. A total of 205 drug targets and 38 potential core targets of P. cuspidatum were confirmed in OKCs. The hub genes included PPARG, SPP1, COL3A1, MMP2, HMOX1, CCL2, CXCL10, VCAM1, RUNX2 and IRF1. Molecular docking showed that the key active ingredients including luteolin and quercetin which exhibited good docking activity with key target proteins (VCAM1, HMOX1 and MMP2). GO enrichment revealed that the pathways of P. cuspidatum acting on OKCs included the response to toxic substance, response to nutrient levels and response to xenobiotic stimulus. P. cuspidatum treatment in OKC could significantly down-regulate COL3A1 and MMP2 expressions in vivo and vitro. Our study indicated that P. cuspidatum is a potential therapeutic candidate for OKCs.

Efficacy of SGPP2 Modulation-Mediated Materials in Ameliorating Facial Wrinkles and Pore Sagging

Skin aging is a complex process with internal and external factors. Recent studies have suggested that enlargement and elongation of skin pores may be early signs of aging in addition to wrinkles and loss of elasticity. This study explores the potential of targeting the SGPP2 gene in keratinocytes to address these emerging concerns. Using siRNA knockdown, we demonstrated that SGPP2 modulates the production of inflammatory cytokines (interleukin (IL)-1β and IL-8). Furthermore, conditioned media experiments revealed that keratinocytes with high SGPP2 expression indirectly influence fibroblast extracellular matrix remodeling, potentially contributing to enlarged pores and wrinkle formation. Based on these findings, we explored a complex formulation containing four SGPP2-modulating compounds. In vitro and in vivo experiments demonstrated the efficacy of the formulation in mitigating fine wrinkles and pore enlargement. This study highlights the significant implications of developing a more effective antiaging cosmetic formulation by targeting underlying inflammatory processes that drive skin aging.

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

Screening and Evaluation of Dermo-Cosmetic Activities of the Invasive Plant Species Polygonum cuspidatum

Polygonum cuspidatum (P. cuspidatum) is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management. P. cuspidatum is well known to have numerous biological properties, containing notably stilbenes, quinones, flavonoids and phenolic acids. The present work proposes a reliable strategy using powerful techniques for the screening and the evaluation of the dermo-cosmetic potential of its aerial parts (AP) and root parts (RP). To the best of our knowledge, only antioxidant and anti-tyrosinase activities were previously evaluated on P. cuspidatum among the targets studied (superoxide dismutase, hyaluronidase, elastase, collagenase and tyrosinase). The results revealed strong antioxidant and anti-collagenase activities, moderate anti-hyaluronidase activity, while weak anti-elastase and anti-tyrosinase activities were observed for ethanolic extracts. Different standards selected and screened on the same targets made it possible to correlate the observed residual activities of produced extracts of P. cuspidatum from Savoie Mont Blanc and their chemical compositions. A structure-activity study was thus conducted on main molecular families, widely represented in the genus Polygonum.

The Invasive Species Reynoutria japonica Houtt. as a Promising Natural Agent for Cardiovascular and Digestive System Illness

Polygoni Cuspidati Rhizoma et Radix, the dry roots and stems of Reynoutria japonica Houtt (called Huzhang, HZ in Chinese), is a traditional and popular chinese medicinal herb for thousands of years. As a widely used ethnomedicine in Asia including China, Japan, and Korea, HZ can invigorate the blood, cool heat, and resolve toxicity, which is commonly used in the treatment of favus, jaundice, scald, and constipation. However, HZ is now considered an invasive plant in the United States and many European countries. Therefore, in order to take advantage of HZ and solve the problem of biological invasion, scholars around the world have carried out abundant research studies on HZ. Until now, about 110 compounds have been isolated and identified from HZ, in which anthraquinones, stilbenes, and flavonoids would be the main bioactive ingredients for its pharmacological properties, such as microcirculation improvement, myocardial protective effects, endocrine regulation, anti-atherosclerotic activity, anti-oxidant activity, anti-tumor activity, anti-viral activity, and treatment of skin inflammation, burns, and scalds. HZ has a variety of active ingredients and broad pharmacological activities. It is widely used in health products, cosmetics, and even animal husbandry feed and has no obvious toxicity. Efforts should be made to develop more products such as effective drugs, health care products, cosmetics, and agricultural and animal husbandry products to benefit mankind.

Drug repurposing against the RNA-dependent RNA polymerase domain of dengue serotype 3 by virtual screening and molecular dynamics simulations

Dengue is an arboviral disease caused by the dengue flavivirus. The NS5 protein of flaviviruses is a potential therapeutic target, and comprises an RNA-dependent RNA polymerase (RDRP) domain that catalyses viral replication. The aim of this study was to repurpose FDA-approved drugs against the RDRP domain of dengue virus serotype 3 (DENV3) using structure-based virtual screening and molecular dynamics (MD) simulations. The FDA-approved drugs were screened against the RDRP domain of DENV3 using a two-step docking-based screening approach with Glide SP and Glide XP. For comparison, four reported DENV3 RDRP inhibitors were docked as standards. The hitlist was screened based on the docking score of the inhibitor with the lowest docking score (PubChem ID: 118797902; reported IC₅₀ value: 0.34 µM). Five hits with docking scores and Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) energy lower than those of 118797902 were selected. The stability of the hit-receptor complexes was investigated using 100 ns MD simulations in an explicit solvent. The results of MD simulations demonstrated that polydatin and betiatide remained stably bound to the receptor, and formed stable interactions with the RDRP domain of DENV3. The hit-receptor interactions were comparable to those of 118797902. The average Prime MM-GBSA energy of polydatin and betiatide was lower than that of 118797902 during simulation, indicating that their binding affinity to DENV3 RDRP was higher than that of the standard. The results of this study may aid in the development of serotype-selective drugs against dengue in the future.Communicated by Ramaswamy H. Sarma.

Reynoutria japonica Houtt for Acute Respiratory Tract Infections in Adults and Children: A Systematic Review

Introduction: Respiratory tract infections (RTIs) are a major cause of morbidity and mortality in some high-risk groups including children and older adults. There is evidence that Chinese herbal medicine has an effect on RTIs. Reynoutria japonica Houtt (better known under its synonym Fallopia japonica (Houtt.) Ronse Decr.) (F. japonica), a commonly used Chinese herbal medicine, has a high content of resveratrol and glycosides. In traditional Chinese medicine theory, F. japonica has the effect of clearing heat in the body, improving blood and qi circulation, eliminating phlegm, and relieving cough, so it may have an effect on RTIs. Methods: This systematic review was registered under PROSPERO CRD42020188604. Databases were searched for randomized controlled trials of F. japonica as a single herb, or as a component of a complex herbal formula for RTIs. Quality of methodology was assessed by two reviewers independently using the Cochrane Risk of Bias Tool. The primary outcome was symptom improvement rate. The secondary outcome measures were fever clearance time, Murray lung injury score and incidence of adverse effects. The extracted data were pooled and meta-analysed by RevMan 5.3 software. Results: Eight RCTs with 1,123 participants with acute RTIs were included in this systematic review, and all the RCTs used F. japonica as part of a herbal mixture. Only one included trial used F. japonica in a herbal mixture without antibiotics in the treatment group. The findings showed that herbal remedies that included F. japonica could increase the symptom improvement rate (risk ratio 1.14, 95% confidence intervals [1.09, 1.20], I2 = 0%, p < 0.00001, n = 7 trials, 1,013 participants), shorten fever duration, reduce Murray lung injury score and did not increase adverse events (RR 0.33, 95% CI [0.11, 1.00], I2 = 0%, p = 0.05, n = 5 trials, 676 participants). Conclusion: There is limited but some evidence that F. japonica as part of a herbal mixture may be an effective and safe intervention for acute RTIs in clinical practice. In future studies it would be preferable to evaluate the effectiveness and safety of using F. japonica without antibiotics for acute RTIs.

Enzymatic Synthesis of Resveratrol α-Glucoside by Amylosucrase of Deinococcus geothermalis

Glycosylation of resveratrol was carried out by using the amylosucrase of Deinococcus geothermalis, and the glycosylated products were tested for their solubility, chemical stability, and biological activities. We synthesized and identified these two major glycosylated products as resveratrol-4'-O-α-glucoside and resveratrol-3-O-α-glucoside by nuclear magnetic resonance analysis with a ratio of 5:1. The water solubilities of the two resveratrol-α-glucoside isomers (α-piceid isomers) were approximately 3.6 and 13.5 times higher than that of β-piceid and resveratrol, respectively, and they were also highly stable in buffered solutions. The antioxidant activity of the α-piceid isomers, examined by radical scavenging capability, showed it to be initially lower than that of resveratrol, but as time passed, the α-piceid isomers' activity reached a level similar to that of resveratrol. The α-piceid isomers also showed better inhibitory activity against tyrosinase and melanin synthesis in B16F10 melanoma cells than β-piceid. The cellular uptake of the α-piceid isomers, which was assessed by ultra-performance liquid chromatography (UPLC) analysis of the cell-free extracts of B16F10 melanoma cells, demonstrated that the glycosylated form of resveratrol was gradually converted to resveratrol inside the cells. These results indicate that the enzymatic glycosylation of resveratrol could be a useful method for enhancing the bioavailability of resveratrol.

Efficient Enzymatic Synthesis of Lipophilic Phenolic Glycoside Azelaic Acid Esters and Their Depigmenting Activity

In this paper, an enzymatic route for synthesizing phenolic glycoside azelaic acid esters was successfully set up via lipase-catalyzed esterification and transesterification. Among the lipases tested, Candida antarctica lipase B (Novozyme 435) showed the highest activity in catalyzing esterification and Thermomyces lanuginosus (Lipozyme TLIM) gave the highest substrate conversion in catalyzing transesterification for the synthesis of ester. The addition of 4A molecular sieves into the reaction system is found to be an effective method for in situ absorption of the byproduct water and methanol, with which the substrate conversions of the enzymatic esterification and transesterification were 98.7 and 95.1%, respectively. Also, the main product ratios in transesterification were above 99.0% with lipozyme TLIM as a catalyst because the hydrolysis reaction was hindered. The results of the physical and biological properties indicate that all esters had higher Clog p values than their parent compounds. Also, the esters showed higher intracellular tyrosinase inhibitory and depigmentating activities than phenolic glycosides, azelaic acid (AA), and their physical mixtures due to their higher membrane penetration and tyrosinase inhibitory effects. In particular, piceid 6″-O-azelaic acid ester (PIA) showed the strongest inhibitory effect against melanin production. Its inhibitory rate was 77.4% at a concentration of 0.25 mM, about 4.2 times higher than that of arbutin (18.5%).

Improving the Condition of European Hare Through Nutrition

The objective of the article is to evaluate the effects of a newly designed granulated mixture enriched with Bohemian knotweed (Reynoutria x bohemica) on European hare (Lepus europaeus) kept at closed farms. The positive influence of knotweed on the microbiome in the digestive system and better usage of the fodder were proven based on biochemical and haematological analysis of blood. Lower manifestation of pathogenic organisms is also expected. Finally, the positive influence on higher weight gains in baby hares was proven, which improves their condition. The results can be used in practice at closed farms breeding European hare focused on releasing bred young hares into open hunting grounds where it is possible to obtain a monetary contribution for the releasing of hares from a grant of the Ministry of Agriculture of the Czech Republic in the field of hunting. Furthermore, the results can be used for feeding hares in open hunting grounds.

The Effect of Reynoutria × Bohemica on the Condition of Capreolus Capreolus and Cervus Elaphus

The objective of the work is to evaluate the effects of a granulated feeding mixture enriched with knotweed (Reynoutria × bohemica) on roe deer (Capreolus capreolus) bred at a closed farm and red deer (Cervus elaphus) bred at a farm. Based on both biochemical and haematological blood analysis, the knotweed is expected to have an influence on the microbiome in the digestive system as well as allowing better utilisation of fodder and lower manifestation of pathogenic organisms. The results are of practical use mainly on farms and in hobby breeding but also in deer parks. Furthermore, the results may be used for feeding deer in open hunting grounds.

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.

Advances in the Tyrosinase Inhibitors from Plant Source

Tyrosinase is a multifunctional copper-containing oxidase which catalyses the oxidation of tyrosine to produce melanin. The alteration in melanin biosynthesis occurs in many diseases. The pigment has a protecting role against skin photo-carcinogenesis, but anomalous melanin pigmentation is an aesthetic problem in human beings. Moreover, the formation of neuromelanin in human brain could contribute to the neurodegeneration associated with Parkinson's disease. Finally, tyrosinase is also responsible for undesired browning in fruits and vegetables. These topics encouraged the search for new inhibitors of this enzyme for pharmaceutical, cosmetic and foods industries. This review is to report recent trends in the discovery of tyrosinase inhibitors from plant sources, to provide a rationale for the continued study of natural tyrosinase inhibitors, and to recognise the potential therapeutic rewards associated with the identification of these agents.

Shedding light on the interaction of polydatin and resveratrol with G-quadruplex and duplex DNA: a biophysical, computational and biological approach

Among polyphenols, trans-resveratrol (tRES) and trans-polydatin (tPD) exert multiple biological effects, particularly antioxidant and antiproliferative. In this work, we have investigated the interaction of tPD with three cancer-related DNA sequences able to form G-quadruplex (G4) structures, as well as with a model duplex, and compared its behaviour with tRES. Interestingly, fluorescence analysis evidenced the ability of tPD to bind all the studied DNA systems, similarly to tRES, with tRES displaying a higher ability to discriminate G4 over duplex with respect to tPD. However, neither tRES nor tPD produced significant conformational changes of the analyzed DNA upon binding, as determined by CD-titration analysis. Computational analysis and biological data confirmed the biophysical results: indeed, molecular docking evidenced the stronger interaction of tRES with the promoter of c-myc oncogene, and immunoblotting assays revealed a reduction of c-myc expression, more effective for tRES than tPD. Furthermore, in vitro assays on melanoma cells proved that tPD was able to significantly reduce telomerase activity, and inhibit cell proliferation, with tRES producing higher effects than tPD.

Profile of Bioactive Compounds in the Morphological Parts of Wild Fallopia japonica (Houtt) and Fallopia sachalinensis (F. Schmidt) and Their Antioxidative Activity

The aim of this study was to determine the content of triterpenoids and polyphenols, and antioxidative activity in leaves, stalks, and roots of plants from the species Fallopia as well as to present the main relationship between them. Polyphenolic compounds and triterpenoids were identified with liquid chromatography-photodiode detector-mass spectrometry/quadrupole time of flight (LC-MS-Q/TOF; qualitatively) and quantified with an ultra-performance liquid chromatography-photodiode detector (UPLC-PDA (quantitatively), and their antioxidative activity was determined with radical scavenging capacity (ABTS) and oxygen radical absorbance capacity (ORAC) assays. Generally, the wild Fallopia japonica Houtt. species had 1.2 times higher content of bioactive compounds and antioxidative activity than Fallopia sachalinensis. Contents of polyphenolic compounds determined in leaves, stalks, and roots were on average 17.81, 10.60, and 9.02 g/100 g of dry weight (DW), whereas the average contents of triterpenoids reached 0.78, 0.70, and 0.50 g/100 g DW, respectively. The leaves were a better source of polymeric procyanidins, phenolic acids, flavones, and flavonols, as well as oleanolic and ursolic acids than the other morphological parts of the tested plants. However, the roots were an excellent source of flavan-3-ols (monomeric and oligomer) and stilbenes, such as resveratrol, and their derivatives. The results obtained showed significant differences between plants of the wild Fallopia species and their morphological parts, and enabled selecting the most valuable morphological part of the tested plants to be used for food enrichment and nutraceuticals production. Therefore, the leaves seem to be the best as potential food additives for health, due to the above-average content of polyphenolic compounds and triterpenoids. In turn, roots, with their high contents of stilbenes and polyphenolic compounds, represent a good material for the medical, pharmaceutical, and cosmetic industries. The principal component analysis of the plants of wild Fallopia species and their morphological parts confirmed significant differences in their chemical composition.

Anti-Melanogenic Potentials of Nanoparticles from Calli of Resveratrol-Enriched Rice against UVB-Induced Hyperpigmentation in Guinea Pig Skin

We already reported that genetically engineered resveratrol-enriched rice (RR) showed to down-regulate skin melanogenesis. To be developed to increase the bioactivity of RR using calli from plants, RR was adopted for mass production using plant tissue culture technologies. In addition, high-pressure homogenization (HPH) was used to increase the biocompatibility and penetration of the calli from RR into the skin. We aimed to develop anti-melanogenic agents incorporating calli of RR (cRR) and nanoparticles by high-pressure homogenization, examining the synergistic effects on the inhibition of UVB-induced hyperpigmentation. Depigmentation was observed following topical application of micro-cRR, nano-calli of normal rice (cNR), and nano-cRR to ultraviolet B (UVB)-stimulated hyperpigmented guinea pig dorsal skin. Colorimetric analysis, tyrosinase immunostaining, and Fontana-Masson staining for UVB-promoted melanin were performed. Nano-cRR inhibited changes in the melanin color index caused by UVB-promoted hyperpigmentation, and demonstrated stronger anti-melanogenic potential than micro-cRR. In epidermal skin, nano-cRR repressed UVB-promoted melanin granules, thereby suppressing hyperpigmentation. The UVB-enhanced, highly expressed tyrosinase in the basal layer of the epidermis was inhibited by nano-cRR more prominently than by micro-cRR and nano-cNR. The anti-melanogenic potency of nano-cRR also depended on pH and particle size. Nano-cRR shows promising potential to regulate skin pigmentation following UVB exposure.

Polygonum cuspidatum extracts as bioactive antioxidaion, anti-tyrosinase, immune stimulation and anticancer agents

In our study, it was applied for the technology of supercritical fluid carbon dioxide extraction to achieve biological constitutes from a Taiwan native plant, Polygonum cuspidatum. We developed bioactive effects of P. cuspidatum extracts via multiple examinations that established bio-purposes at a range of dosage ranges. The research of P. cuspidatum extracts indicated that they possessed anti-oxidative properties on radical-scavenging abilities, reducing activities and metal chelating powers in dose-dependant manners. The extracts also had minor in vitro mushroom tyrosinase suppression and decreased cellular tyrosinase activities and melanin production in B16-F10 cells. Immunologically, P. cuspidatum extracts enhanced the release of tumor necrosis factor α (TNF-α) induced by THP-1 macrophage cell line. In addition, the cell proliferation showed anti-proliferation in dose-dependent manner on human skin melanoma cells, A375 and A375.S2, of the extracts suggesting biological constitutes employed the anti-cancer possessions. This is the first statement presenting bioactivities on P. cuspidatum extracts including anti-oxidation, immune stimulation, anti-tyrosinase and anti-melanoma as far as we know.

Quantitative analysis of ligand effects on bioefficacy of nanoemulsion encapsulating depigmenting active

Efficient skin delivery of active molecules is the main challenge to overcome in order to achieve significant therapeutic efficiency of cosmetics or dermo-pharmaceutical products. Nanocarriers such as nanoemulsions have been envisaged to overcome main challenges of active solubilization, protection and transport to their site of biological action. Nonetheless, their skin permeation is still limited and a new approach is required to significantly improve bioavailability. We here explored the possibility of increasing the whitening activity of a model active, licorice, by implementing a targeting approach of nanoemulsions to melanocyte cells. Targeting requires particle surface modification with specific molecules favoring nanoemulsion/cells contact through ligand-receptor interactions. The uniqueness of our strategy is that unlike classical covalent chemical grafting, we propose a self-assembled strategy based on a selection of amphiphilic ligands able to localize at nanoemulsion droplets interface. Four ligand candidates were thus assayed in terms of formulation and in vitro biological evaluation: a palmitoyl-peptide (palmitoyl-GQPR), a lipidized hyaluronic acid (caproyl-HA) and two amphiphilic actives (polydatin and isopilosine). A functional analysis based on a cellular assay of melanin inhibition was realized. The intrinsic properties of ligand candidates were first evaluated. Then, nanoemulsions encapsulating a drug model, licorice, and targeted with the different ligand candidates were assayed. The use of caproyl-HA significantly improved bioefficacy of the encapsulated licorice, suggesting a better interaction with the cells. The improved value observed was not attributed to a synergetic action as caproyl-HA did not evidence intrinsic melanogenesis modulation activity. In this study, we demonstrated the feasibility of targeting nanoemulsion droplets without chemical covalent modification of nanoemulsion droplets to increase bioefficacy of encapsulated drugs in vitro.

Polydatin: a review of pharmacology and pharmacokinetics

CONTEXT

Polydatin, also named piceid (3,4',5-trihydroxystilbene-3-β-d-glucoside, PD), is a monocrystalline compound isolated from Polygonum cuspidatum Sieb. et Zucc. (Polygonaceae), but is also detected in grape, peanut, hop cones, red wines, hop pellets, cocoa-containing products, chocolate products and many daily diets. There are numerous investigations reported of PD in the past 22 years, but they are usually scattered across various publications, which may block further research and clinical use of PD.

OBJECTIVE

The article summarizes and evaluates the published scientific information of PD pharmacological effects and pharmacokinetics since 1990.

MATERIALS AND METHODS

The information from 98 cases included in this review was compiled using major databases such as MEDLINE, Elsevier, Springer, PubMed, Scholar and CNKI.

RESULTS

Numerous pharmacological investigations of PD mainly focus on cardiovascular effects, neuroprotection, anti-inflammatory and immunoregulatory effects, anti-oxidation, anti-tumor, liver and lung protection, etc.

CONCLUSION

A great number of pharmacological and pharmacokinetic investigations in the past 22 years have demonstrated that PD has favorable therapeutic properties, indicating its potential as an effective material. However, further research is needed to explore its molecular mechanisms of action and definitive target proteins.

Botany, phytochemistry, pharmacology, and potential application of Polygonum cuspidatum Sieb.et Zucc.: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum cuspidatum Sieb. et Zucc. (Polygonum cuspidatum), also known as Reynoutria japonica Houtt and Huzhang in China, is a traditional and popular Chinese medicinal herb. Polygonum cuspidatum with a wide spectrum of pharmacological effects has been used for treatment of inflammation, favus, jaundice, scald, and hyperlipemia, etc.

AIM OF THE REVIEW

The present paper reviews the traditional applications as well as advances in botany, phytochemistry, pharmacodynamics, pharmacokinetics and toxicology of this plant. Finally, the tendency and perspective for future investigation of this plant are discussed, too.

MATERIALS AND METHODS

A systematic review of literature about Polygonum cuspidatum is carried out using resources including classic books about Chinese herbal medicine, and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science and others.

RESULTS

Polygonum cuspidatum is widely distributed in the world and has been used as a traditional medicine for a long history in China. Over 67 compounds including quinones, stilbenes, flavonoids, counmarins and ligans have been isolated and identified from this plant. The root of this plant is used as the effective agent in pre-clinical and clinical practice for regulating lipids, anti-endotoxic shock, anti-infection and anti-inflammation, anti-cancer and other diseases in China and Japan.

CONCLUSION

As an important traditional Chinese medicine, Polygonum cuspidatum has been used for treatment of hyperlipemia, inflammation, infection and cancer, etc. Because there is no enough systemic data about the chemical constituents and their pharmacological effects or toxicities, it is important to investigate the pharmacological effects and molecular mechanisms of this plant based on modern realization of diseases' pathophysiology. Drug target-guided and bioactivity-guided isolation and purification of the chemical constituents from this plant and subsequent evaluation of their pharmacologic effects will promote the development of new drug and make sure which chemical constituent or multiple ingredients contributes its pharmacological effects. Additionally, chemicals and their pharmacological effects of the other parts such as the aerial part of this plant should be exploited in order to avoid resource waste and find new chemical constituents.

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.