Mushroom Tyrosinase Inhibition Research Articles

Chemical Composition and Bioactivity of Essential Oil of Seed and Leaf from Alpinia speciosa Grown in Taiwan

AbstractThe essential oil, methanolic and aqueous extracts of the seeds and leaves of Alpinia speciosa (Wendl.) K. Schum. (Zingiberaceae) were assayed for their mushroom tyrosinase inhibition, larvicidal effect, antioxidant property and antimicrobial activity. The main components of the seeds were camphor, sabinene, (Z)‐β‐ocimene, 1,8‐cineole, terpinen‐4‐ol and α‐pinene, while the leaves contains camphor, sabinene, γ‐terpinene, terpinen‐4‐ol and α‐terpineol. The seed and leaf oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving 74 and 81% inhibition at 1000 ppm, respectively. The seed oil exhibits the mosquito larvicidal activity with 2 h and 24 h LC50 value of 125 and 87 ppm, respectively, whereas the leaf oil shows larvicidal activity with 2 h and 24 h LC50 value of 64 and 32 ppm, respectively. The methanolic and aqueous extracts of A. speciosa show remarkable antioxidant effect. This activity can be attributed to the presence of the phenolic compounds. The essential oil of A. speciosa exhibits a strong broad‐spectrum antimicrobial activity against all test organisms. The seeds and leaves of A. speciosa could be considered as a natural tyrosinase inhibition, mosquito larvicidal, antioxidant and antimicrobial source.

A newly synthesized, potent tyrosinase inhibitor: 5-(6-Hydroxy-2-naphthyl)-1,2,3-benzenetriol

In searching for new agents with a depigmenting effect, we synthesized a derivative of resveratrol, 5-(6-hydroxy-2-naphthyl)-1,2,3-benzenetriol (5HNB) with a potent tyrosinase inhibitory activity. 5HNB inhibited mushroom tyrosinase with an IC 50 value of 2.95 μM, which is more potent than the well-known anti-tyrosinase activity of kojic acid (IC 50 = 38.24). The results of the enzymatic inhibition kinetics by Lineweaver–Burk analysis indicated 5HNB inhibits tyrosinase non-competitively when l-tyrosine was used as the substrate. Based on the strong inhibitory action of 5HNB, it is expected that 5HNB can suppress melanin production in which tyrosinase plays the essential role. Our expectation was confirmed by the experimentations with B16 melanoma cells in which 5HNB inhibited melanin production. We propose that 5HNB might have skin-whitening effects as well as therapeutic potential for treating skin pigmentation disorders.

(−)-N-Formylanonaine from Michelia alba as a human tyrosinase inhibitor and antioxidant

Tyrosinase is the first and rate limiting enzyme in the synthesis of melanin pigments for coloring hair, skin, and eyes. As reported in this study, a natural product, (−)-N-formylanonaine isolated from the leaves of Michelia alba D.C. (Magnolianceae), was found to inhibit mushroom tyrosinase with an IC50 of 74.3μM and to have tyrosinase and melanin reducing activities in human epidermal melanocytes without apparent cytotoxicity to human cells, superior to the known tyrosinase inhibitors, such as kojic acid and 1-phenyl-2-thiourea (PTU). Based on homology modeling, the compound binds the active site by coordinating with two Cu2+ ions. In addition, the compound had antioxidation activities in tests for scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power, and chelating metal ions. To our knowledge, this is the first study to reveal the bioactivities of (−)-N-formylanonaine from this plant species.

Biotransformation of mulberroside A from Morus alba results in enhancement of tyrosinase inhibition

Mulberroside A, a glycosylated stilbene, was isolated and identified from the ethanol extract of the roots of Morus alba. Oxyresveratrol, the aglycone of mulberroside A, was produced by enzymatic hydrolysis of mulberroside A using the commercial enzyme Pectinex. Mulberroside A and oxyresveratrol showed inhibitory activity against mushroom tyrosinase with an IC(50) of 53.6 and 0.49 microM, respectively. The tyrosinase inhibitory activity of oxyresveratrol was thus approximately 110-fold higher than that of mulberroside A. Inhibition kinetics showed mulberroside A to be a competitive inhibitor of mushroom tyrosinase with L-tyrosine and L-DOPA as substrate. Oxyresveratrol showed mixed inhibition and noncompetitive inhibition against L-tyrosine and L-DOPA, respectively, as substrate. The results indicate that the tyrosinase inhibitory activity of mulberroside A was greatly enhanced by the bioconversion process.

Synthesis and biological activity of oxadiazole and triazolothiadiazole derivatives as tyrosinase inhibitors

A series of 16 oxadiazole and triazolothiadiazole derivatives were designed, synthesized and evaluated as mushroom tyrosinase inhibitors. Five derivatives were found to display high inhibition on the tyrosinase activity ranging from 0.87 to 1.49μM. Compound 5 exhibited highest tyrosinase inhibitory activity with an IC50 value of 0.87±0.16μM. The in silico protein–ligand docking using autodock 4.1 was successfully performed on compound 5 with significant binding energy value of −5.58kcal/mol. The docking results also showed that the tyrosinase inhibition might be due to the metal chelating effect by the presence of thione functionality in compounds 1–5. Further studies revealed that the presence of hydrophobic group such as cycloamine derivatives played a major role in the inhibition. Piperazine moiety in compound 5 appeared to be involved in an extensive hydrophobic contact and a 2.9Å hydrogen bonding with residue Glu 182 in the active site.

Tyrosinase inhibitors isolated from the roots of Paeonia suffruticosa

The inhibition of mushroom tyrosinase by Paeonia suffruticosa root-derived materials was evaluated. Six tyrosinase inhibitors were isolated by ethanol extraction, n-hexane, ethyl acetate, n-BuOH, and water partition, silica gel column chromatography, Sephadex LH-20, Lobar PR-8, and high-performance liquid chromatography methods, and they were identified as kaempferol (I), quercetin (II), mudanpioside B (III), benzoyloxypaeoniflorin (IV), mudanpioside H (V), and pentagalloyl-beta-(D)-glucose (VI) on the basis of spectroscopic evidence. The inhibitory activities of compounds I to VI against mushroom tyrosinase were determined with IC(50) values of 0.120, 0.108, 0.368, 0.453, 0.324, and 0.063 mM, respectively. The kinetic study indicated that all purified inhibitors acted competitively for the L-dopa binding site of the enzyme, with an exception of compound VI, which acted non-competitively.

ChemInform Abstract: Discovery of 4‐Functionalized Phenyl‐O‐β‐D‐glycosides as a New Class of Mushroom Tyrosinase Inhibitors.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Properties and antityrosinase activity of sericin from various extraction methods

The present study investigated the chemical properties and antityrosinase activities of SS (silk sericin) extracted from different Thai silk strains via various extraction methods. Different silk strains contain distinct SS with various amino acid compositions, which are significantly influenced by the extraction method used. Urea extraction of SS was the only method that provided clearly distinguishable bands and had the most significant impact on SS conformation as illustrated by FTIR (Fourier-transform infrared) spectra. The use of urea or either acidic or alkaline chemicals in the extraction process also influenced SS thermal behaviour. With regard to biological activity, SS extracted using urea exhibited the highest antityrosinase activity, whereas alkali-degraded SS showed no inhibition of mushroom tyrosinase. Pigments, primarily flavonoids and carotenoids from silk cocoons, were also found to enhance tyrosinase inhibition of SS.

Evaluation of anti-pigmentary effect of synthetic sulfonylamino chalcone

The 4′-( p-toluenesulfonylamino)-4-hydroxychalcone (TSAHC), which bears inhibitory chemotypes for both α-glucosidase and tyrosinase, was evaluated for tyrosinase activity and depigmenting ability relative to compounds designed to only target tyrosianse activity. TSAHC emerged to be a competitive reversible inhibitor of mushroom tyrosinase. More importantly, it was also able to return the melanin content of α-melanocyte stimulated by α-MSH to base levels unlike other inhibitors that only targeted tyrosinase. The Western blot for expression levels of proteins involved in melanogenesis showed that TSAHC significantly decreased three main tyrosinase related protein in melanin biosynthesis, tyrosinase, TRP-1 and TRP-2.

Effects of vitamin C vs. multivitamin on melanogenesis: comparative study in vitro and in vivo

Vitamin C has been used for the treatment of hyperpigmented diseases. However, there is no study available on hypopigmenting effect of multivitamin. To investigate the inhibitory effects of multivitamin and vitamin C on melanogenesis. We assessed the effect of multivitamin and vitamin C on cell viability, melanogenesis, and mushroom tyrosinase. The antioxidant activity of multivitamin and vitamin C was measured. We performed the Western blot analysis to study the effect of multivitamin and vitamin C on the expression of tyrosinase, microphthalmia-associated transcription factor (MITF), extracellular signal-regulated kinase (ERK), and Akt/protein kinase B. In a clinical trial, 20 melasma patients were treated with split face iontophoresis using either multivitamin or vitamin C. We evaluated the hypopigmenting effects of multivitamin and vitamin C through colorimetric measurement. Both vitamin C and multivitamin inhibited melanogenesis with low cytotoxicity. Multivitamin reduced melanin contents greater than vitamin C. However, the effects of vitamin C are greater than those of multivitamin on mushroom tyrosinase inhibition and antioxidation. In the Western blot, the reduced tyrosinase expression and MITF level were observed only in multivitamin-treated group, and not in vitamin C-treated group. No changes of ERK and Akt activation were observed in both multivitamin and vitamin C-treated groups. After 12 weeks of treatment with iontophoresis, both multivitamin and vitamin C were effective for melasma. Multivitamin has shown more anti-melanogenic effect than vitamin C via the downregulation of MITF.

Acetoside inhibits α-MSH-induced melanin production in B16 melanoma cells by inactivation of adenyl cyclase

Abstract Objectives The aim of the study was to determine the mechanism of the whitening effect of acteoside. Methods We used tyrosinase activity and melanin production stimulated in B16 melanoma cells by α-melanocyte stimulating hormone (α-MSH) or forskolin to measure the whitening effect of acteoside. Key findings Acteoside did not directly inhibit mushroom tyrosinase activity, but dose-dependently inhibited tyrosinase activity and melanin production in B16 melanoma cells stimulated by 1 μmol/l α-MSH. Acteoside also reduced cyclic AMP levels in cells stimulated by 1 μmol/l α-MSH, suggesting direct inhibition of adenyl cyclase. Acteoside also inhibited productionofbothmelanin and cyclic AMP in cells stimulated by 1 μmol/l forskolin, an adenyl cyclase activator. Acteoside showed antioxidant activity in a cell-free DPPH (1-diphenyl-2-picrylhydroazyl) assay and inhibited generation of intracellular reactive oxygen species. Conclusions These results suggest that the whitening activity of acteoside results from inhibition of adenyl cyclase and α-MSH signalling.

Papuabalanols A and B, New Tannins from Balanophora papuana

Two new dehydrohexahydroxydiphenoyl (DHHDP) esters of dihydrochalcone glycosides, papuabalanols A (1) and B (2) were isolated from the ethyl acetate extract of Balanophora papuana. Their structures were elucidated on the basis of spectroscopic data and chemical evidences. Papuabalanol A (1) showed moderate vasodilator effect on rat aorta and papuabalanol B (2) showed potent inhibition of mushroom tyrosinase and anti-melanogenesis in B16 mouse melanoma cells.

Enhanced cell permeability of kojic acid–phenylalanine amide with metal complex

Kojic acid–phenylalanine amide (KA–F–NH 2), which showed an excellent tyrosinase inhibitory activity, did not inhibit melanogenesis in melanocyte due to its low cell permeability. To enhance its cell permeability by increasing lipophilicity, we prepared metal coordination compounds of KA–F–NH 2 and characterized them by FT-IR and ICP analysis. The metal complex of KA–F–NH 2 inhibited mushroom tyrosinase activity as much as KA–F–NH 2 and reduced melanin contents in melanocyte efficiently.

Picolyl Alkyl Amines As Novel Tyrosinase Inhibitors: Influence of Hydrophobicity and Substitution

Several novel picolyl alkyl amine derivatives (A-L) were synthesized, and the influence of hydrophobicity and substitution on the inhibition of mushroom tyrosinase toward both monophenolase and diphenolase activities are described. Alpha-, beta-, and gamma-picolyl amines are neither the substrates nor the inhibitors; however, the inhibition is induced by the incorporation of an alkyl chain. The inhibition was strongly dependent on the substitution on a pyridine ring, and the inhibition follows the trend of alpha-picolyl alkyl amines (A, D, G) < beta-picolyl alkyl amines (B, E, H) < gamma-picolyl alkyl amines (C, F, I). The inhibition kinetics have been investigated, and gamma-substituted derivatives were found to be a mixed type of inhibitor, whereas beta-substituted derivatives were found to exhibit uncompetitive inhibition toward the oxidation of L-DOPA.

Acetoside inhibits α-MSH-induced melanin production in B16 melanoma cells by inactivation of adenyl cyclase

The aim of the study was to determine the mechanism of the whitening effect of acteoside. We used tyrosinase activity and melanin production stimulated in B16 melanoma cells by alpha-melanocyte stimulating hormone (alpha-MSH) or forskolin to measure the whitening effect of acteoside. Acteoside did not directly inhibit mushroom tyrosinase activity, but dose-dependently inhibited tyrosinase activity and melanin production in B16 melanoma cells stimulated by 1 micromol/l alpha-MSH. Acteoside also reduced cyclic AMP levels in cells stimulated by 1 micromol/l alpha-MSH, suggesting direct inhibition of adenyl cyclase. Acteoside also inhibited production of both melanin and cyclic AMP in cells stimulated by 1 micromol/l forskolin, an adenyl cyclase activator. Acteoside showed antioxidant activity in a cell-free DPPH (1-diphenyl-2-picrylhydroazyl) assay and inhibited generation of intracellular reactive oxygen species. These results suggest that the whitening activity of acteoside results from inhibition of adenyl cyclase and alpha-MSH signalling.

Discovery of 4-functionalized phenyl -O-β- d-glycosides as a new class of mushroom tyrosinase inhibitors

A series of 4-functionalized phenyl -O-β- d-glycosides were designed, synthesized and evaluated as a new class of mushroom tyrosinase inhibitors. The results demonstrated that compounds 6a– 13a bearing a thiosemicarbazide moiety exhibited potent activities with IC 50 values range from 0.31 to 52.8 μM. Particularly, compound 9a containing acetylated glucose moiety was found to be the most active molecule with an IC 50 value of 0.31 μM. SARs analysis suggested that (1) the thiosemicarbazide moiety remarkably contributed to the increase of inhibitory effects on tyrosinase; (2) the configuration and bond type of sugar moiety also played a very important role in determining their inhibitory activities. The inhibition kinetics and inhibition mechanism study revealed that compound 9a was reversible and competitive type inhibitor, whereas compound 13a was reversible and competitive–uncompetitive mixed-II type inhibitor.

Kinetic Evaluation of Aminoethylisothiourea on Mushroom Tyrosinase Activity

This study demonstrates that aminoethylisothiourea (AET), a potent inhibitor of inducible nitric oxide synthase, is an irreversible competitive inhibitor of mushroom tyrosinase by chelation to the active site of tyrosinase when L-3,4-dihydroxyphenylalanine was assayed spectrophotometrically. The spectrophotometric recordings of the inhibition of tyrosinase by AET were characterized by the presence of a lag period prior to the attainment of an inhibited steady-state rate. The lag period corresponded to the time in which AET was reacting with the enzymatically generated o-quinone. Increasing AET concentrations provoked longer lag periods as well as a concomitant decrease in the tyrosinase activity. Both lag period and steady-state rate were dependent on AET, substrate, and tyrosinase concentrations. The inhibition of diphenolase activity of tyrosinase by AET showed positive kinetic cooperativity which arose from the protection of both substrate and o-quinone against inhibition by AET. The UV-visible spectrum of a mixture of tyrosinase and AET exhibited a characteristic shoulder peak ascribed to the chelation of AET to the active site of tyrosinase. Moreover, the presence of copper ions only partially prevented but not reverted mushroom tyrosinase inhibition when CuSO(4) was added to the assay medium on tyrosinase activity.

Short-Sequence Oligopeptides with Inhibitory Activity against Mushroom and Human Tyrosinase

Cutaneous hyperpigmentation is a common disorder due to excess melanin production by the enzyme tyrosinase. The gold standard for treatment is hydroquinone (HQ), which reduces pigmentation through its toxicity to melanocytes rather than via tyrosinase inhibition. We screened an internal library for oligopeptides that inhibited both mushroom and human tyrosinase but showed no cytotoxicity to human melanocytes. We identified two highly active inhibitory sequences, P3 and P4, of 8- and 10-amino-acid-length, respectively. Mushroom tyrosinase inhibition was dose-dependent with IC(50) (half-maximal inhibitory concentration) values of 123 and 40 microM, respectively, compared with 680 microM for HQ. Other oligopeptides showed weaker or no inhibitory activity. Kinetic studies showed that P3 and P4 are competitive inhibitors of mushroom tyrosinase. At 100 microM, P3 and P4 inhibited human tyrosinase by 25-35%. This inhibition partially depended on whether L-dopa or L-tyrosine was the substrate, suggesting that tyrosinase may contain contains two distinct catalytic sites. Treatment of melanocytes with 100 microM P3 or P4 for 7 days led to a 27 or 43% reduction in melanin content. This inhibition was independent of cell proliferation and cytotoxic effects. Our data suggest that peptide-mediated inhibition of melanogenesis is due to reduction in tyrosinase activity.

Synthesis and evaluation of 5-benzylidene(thio)barbiturate-β-d-glycosides as mushroom tyrosinase inhibitors

A series of 5-benzylidene(thio)barbiturate-β-d-glycosides were designed, synthesized and evaluated as a new class of mushroom tyrosinase inhibitors. The results demonstrated that most of compounds had more potent inhibitory activities than arbutin (IC50 8.4mmol/L). Compound 12b was found to be the most potent inhibitor with IC50 value of 0.05mmol/L. SARs analysis suggested that (1) 5-benzylidenethiobarbiturate substructures were efficacious for the inhibitory activity; (2) the lipophilic property of acetylated sugar moiety facilitated the inhibitory potency; (3) the hydroxyl group of 3′-configuration contributed to the increase of inhibitory effects. In addition, the inhibition mechanism study revealed that 5-benzylidene(thio)barbiturate-β-d-glycosides were irreversible inhibitors.

The Antimicrobial Activity, Mosquito Larvicidal Activity, Antioxidant Property and Tyrosinase Inhibition of Piper Betle

AbstractThe essential oil and methanolic and aqueous extracts of Piper betle L. were assayed for their antimicrobial activity, mosquito larvicidal activity, antioxidant property and mushroom tyrosinase inhibition. The methanolic and aquaous extracts showed strong activity against the yeasts: C. albicans, and M. pachydermatis. The crude essential oil exhibited a broad‐spectrum strong antimicrobial activity against all test organisms. The strongest activity was observed against C. albicans, followed by S. aureus and M. pachydermatis. The chemical composition of the essential oil and its fractions was analyzed by GC/MS analysis. Eugenol (36.2%), chavibetol acetate (16.9%), 4‐allylphenyl acetate (9.4%) and 4‐allylphenol (7.2%) were the main components, comprising 69.7% of the oil. The fractionation of the essential oil gave two fractions. Fraction I was rich in eugenol (71.3%) and fraction II in eugenol (46.4%), chavibetol acetate (19.4%) and 4‐allylphenyl acetate (11.8%). The essential oil exhibited the mosquito larvicidal activity with 2 h and 24 h LD50 value of 86 and 48 ppm, respectively. The methanolic extract of P. betle showed larvicidal activity with 2 h and 24 h LD50 value of 153 and 125 ppm, respectively, whereas the aqueous extract showed slight active. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. P. betle showed remarkable antioxidant activity in DPPH and reducing power assays. The activity observed can be attributed to the presence of the phenolic compounds. The essential oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving an IC50 value of 126 ppm. The fraction I showed a strong inhibition of tyrosinase activity, giving an IC50 value of 115 ppm. The presence of 4‐allylphenolic components in the essential oil may play an important role in the inhibition of tyrosinase. In conclusion, the results presented here show that Piper betle essential oil could be considered as a natural antimicrobial, mosquito larvicidal, antioxidant and tyrosinase inhibition source.