Mushroom Tyrosinase Inhibition Research Articles

Patchouli Alcohol: A Potent Tyrosinase Inhibitor Derived from Patchouli Essential Oil with Potential in the Development of a Skin-Lightening Agent

The inhibitory effects of Pogostemon cablin essential oil (patchouli essential oil, PEO) and its primary bioactive compound, patchouli alcohol (PA), on tyrosinase and melanin were investigated in vitro and ex vivo. Treatment with PEO and PA significantly, as well as dose-dependently, reduced forskolin (FRK)-induced melanin biosynthesis, cellular tyrosinase activity, and tyrosinase (TYR) protein expression. However, the transcriptional levels of TYR and tyrosinase-related proteins (TRP-1 and TRP-2) remained unaffected. These results suggest that PEO and PA may directly interrupt tyrosinase enzyme activity, leading to a reduction in melanin biosynthesis. Further experiments supported this notion, revealing that both PEO and PA significantly and dose-dependently inhibited mushroom tyrosinase activity in both the monophenolase and diphenolase phases. Additionally, an in silico molecular docking analysis was performed, utilizing a homology model of human tyrosinase. In conclusion, these findings strongly suggest that patchouli essential oil and its primary bioactive component, patchouli alcohol, hold promise as potential treatments for hyperpigmentary skin conditions and in the development of cosmetic products designed to lighten the skin.

Pulp or Peel? Comparative Analysis of the Phytochemical Content and Selected Cosmetic-Related Properties of Annona cherimola L., Diospyros kaki Thumb., Cydonia oblonga Mill. and Fortunella margarita Swingle Pulp and Peel Extracts.

Fruit peels might be a valuable source of active ingredients for cosmetics, leading to more sustainable usage of plant by-products. The aim of the study was to evaluate the phytochemical content and selected biological properties of hydroglycolic extracts from peels and pulps of Annona cherimola, Diospyros kaki, Cydonia oblonga, and Fortunella margarita as potential cosmetic ingredients. Peel and pulp extracts were compared for their antiradical activity (using DPPH and ABTS radical scavenging assays), skin-lightening potential (tyrosinase inhibitory assay), sun protection factor (SPF), and cytotoxicity toward human fibroblast, keratinocyte, and melanoma cell lines. The total content of polyphenols and/or flavonoids was significantly higher in peel than in pulp extracts, and the composition of particular active compounds was also markedly different. The HPLC-MS fingerprinting revealed the presence of catechin, epicatechin and rutoside in the peel of D. kaki, whereas kaempferol glucoside and procyanidin A were present only in the pulp. In A. cherimola, catechin, epicatechin and rutoside were identified only in the peel of the fruit, whereas procyanidins were traced only in the pulp extracts. Quercetin and luteolinidin were found to be characteristic compounds of F. margarita peel extract. Naringenin and hesperidin were found only in the pulp of F. margarita. The most significant compositional variety between the peel and pulp extracts was observed for C. oblonga: Peel extracts contained a higher number of active components (e.g., vicenin-2, kaempferol rutinoside, or kaempferol galactoside) than pulp extract. The radical scavenging potential of peel extracts was higher than of the pulp extracts. D. kaki and F. margarita peel and pulp extracts inhibited mushroom and murine tyrosinases at comparable levels. The C. oblonga pulp extract was a more potent mushroom tyrosinase inhibitor than the peel extract. Peel extract of A. cherimola inhibited mushroom tyrosinase but activated the murine enzyme. F. margarita pulp and peel extracts showed the highest in vitro SPF. A. cherimola, D. kaki, and F. margarita extracts were not cytotoxic for fibroblasts and keratinocytes up to a concentration of 2% (v/v) and the peel extracts were cytotoxic for A375 melanoma cells. To summarize, peel extracts from all analyzed fruit showed comparable or better cosmetic-related properties than pulp extracts and might be considered multifunctional active ingredients of skin lightening, anti-aging, and protective cosmetics.

Green fabrication of silver nanoparticles and it’s in vitro anti-bacterial, anti-biofilm, free radical scavenging and mushroom tyrosinase efficacy evaluation

This paper reports a fast, reliable, and efficient protocol for the synthesis of silver nanoparticles using the medicinal plant Paeonia Japonica (PJ) root extract and the in-vitro biological activities of the synthesized AgNPs. The results of XRD and TEM analysis showed that the particles are in 28 nm size with spherical morphology. The PJ–AgNPs portrayed excellent anti-bacterial activity against the gram (+ve) and (−ve) microorganism studied in dose dependent manner. It exhibits very good anti-biofilm activity against the pathogenic S. Aureus with respect to the dose used (89 % inhibition at 100 µg/mL dose). Further it has the ability to scavenge the DPPH free radical efficiently (96.5 % scavenging at 200 µg/mL dose). Added to this the synthesized PJ-AgNPs displayed a very good mushroom tyrosinase inhibition at the tested concentrations. The above results indicate the potential of silver nanoparticles synthesized using PJ root extract can be used as an antibacterial, anti-biofilm, anti-oxidant, enzyme inhibitor in the food, medical and cosmetic industry.

In vitro and in vivo anti-pigmentation effects of 2-mercaptobenzimidazoles as nanomolar tyrosinase inhibitors on mammalian cells and zebrafish embryos: Preparation of pigment-free zebrafish embryos

Recently, 10 2-mercaptobenzo[d]imidazole (2-MBI) compounds (1–10) were synthesized. Although all 2-MBI compounds are tyrosinase inhibitors that inhibit mushroom tyrosinase at extremely low concentrations (IC50 values: 20–740 nM) and effectively inhibit the browning of apples, to our knowledge, no studies have determined whether 2-MBI compounds inhibit mammalian tyrosinase. Mammalian tyrosinase is different from mushroom tyrosinase in its distribution within the cell and has structural characteristics that are different from mushroom tyrosinase in amino acid sequence and in the presence of a quaternary structure. Thus, the effect of the 10 2-MBI compounds on mammalian tyrosinase activity was investigated in B16F10 cells. Six compounds (1–6) exhibited stronger intracellular tyrosinase inhibition than that of kojic acid and phenylthiourea (PTU), which are known to be the most potent tyrosinase inhibitors; their strong tyrosinase inhibitory activity robustly inhibited intracellular melanin production in B16F10 cells. None of the tested 2-MBI compounds exhibited appreciable cytotoxicity in HaCaT and B16F10 cells. To confirm the anti-melanogenic efficacy of the 2-MBI compounds in vivo, a zebrafish embryo model was used. At concentrations 100 times lower than kojic acid, most 2-MBI compounds demonstrated much stronger depigmentation efficacy than that of kojic acid, and three 2-MBI compounds (2–4) showed depigmentation activity similar to or more potent than that of PTU, resulting in nearly pigment-free zebrafish embryos. These results suggest that 2-MBI compounds may be potential therapeutic agents for hyperpigmentation-related disorders.

Design of potent tyrosinase inhibiting N-arylated-4-yl-benzamides bearing 2-aminothiazole-triazole bi-heterocycles: mechanistic insight through enzyme inhibition, kinetics and computational studies.

By using a convergent methodology, a unique series of N-arylated 4-yl-benzamides containing a bi-heterocyclic thiazole-triazole core was synthesized and the structures of these hybrid molecules, 9a-k, were corroborated through spectral analyses. The in vitro studies of these multi-functional molecules demonstrated their potent mushroom tyrosinase inhibition relative to the standard used. The kinetics mechanism was exposed by lineweaver-burk plots which revealed that, 9c, inhibited mushroom tyrosinase non-competitively by forming an enzyme-inhibitor complex. The inhibition constant Ki calculated from Dixon plots for this compound was 0.016 μM. The computational study was also consistent with the experimental results and these molecules disclosed good results of all scoring functions and interactions, which suggested a good binding to mushroom tyrosinase. So, it was predicted from the inferred results that these molecules might be considered as promising medicinal scaffolds for the diseases associated with the over-expression of this enzyme.

Thiazol-4(5H)-one analogs as potent tyrosinase inhibitors: synthesis, tyrosinase inhibition, antimelanogenic effect, antioxidant activity, and in silico docking simulation

As the β-phenyl-α,β-unsaturated carbonyl (PUSC) structure was previously identified to play a key role in tyrosinase inhibition, 14 analogs with a PUSC structure built on a thiazol-4(5H)-one scaffold were synthesized using Knoevenagel condensation to serve as potential tyrosinase inhibitors. Through mushroom tyrosinase inhibition experiments, two analogs 9 and 11 were identified as potent tyrosinase inhibitors, with 11 exhibiting an IC50 value of 0.4 ± 0.01 μM, which indicates its 26-fold greater potency than kojic acid. Kinetic studies using Lineweaver-Burk plots revealed that 9 and 11 are competitive and mixed-type inhibitors, respectively; these kinetic results were supported by docking simulations. According to the B16F10 cell-based experiments, 9 and 11 inhibited melanogenesis more effectively than kojic acid due to their potent cellular tyrosinase inhibitory activity. In addition, analogs 9 and 11 exhibited moderate-to-strong antioxidant capacity, scavenging ABTS+, DPPH, and ROS radicals. In particular, analog 12 with a catechol moiety exhibited very strong ROS-scavenging activity, similar to Trolox. These results suggest that analogs 9 and 11, which exhibit potent tyrosinase inhibitory activity in mushroom and mammalian cells and anti-melanogenic effects in B16F10 cells, are promising antibrowning agents for crops and skin lightening agents for hyperpigmentation-related diseases.

Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent

Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.

Evaluation of antioxidant and anti-tyrosinase activities of surfactant and alcohol extracted Combretum Indicum leaves

Combretum Indicum (CI), which contains numerous bioactive compounds, has been used in traditional medicine for a variety of reasons, including the treatment of skin conditions. This study investigates the antioxidant and anti-tyrosinase activities of CI leaves extracted using different surfactants (Triton X-100 and Vitamin E TPGS) at concentrations of 1%, 2%, and 3%, as well as various alcohol solvents (acetone, methanol, and ethanol) at concentrations of 50%, 70%, and 90%. The antioxidant activity of the extracts has been evaluated using Total Phenolic Content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), while the anti-tyrosinase activity was assessed through a mushroom tyrosinase inhibition assay. Prior to analysis, CI leaves had been macerated, extracted, and freeze-dried. The research established that ethanol at a concentration of 50% is the optimum solvent to extract CI leaves, as it demonstrated good antioxidant and anti-tyrosinase action with a high percentage of yield and total phenolic content. As a result, the outcomes of this study contribute to a better understanding of the potential applications of CI leaf extract in cosmetics, notably in the treatment of oxidative stress and hyperpigmentation. Further study and development in this field could lead to the creation of effective and natural cosmetic products produced from CI leaves that have antioxidant and anti-tyrosinase effects.

In silico and in vitro studies of novel derivatives of tyrosol and raspberry ketone as the mushroom tyrosinase inhibitors.

Tyrosinase is the key enzyme for melanin biosynthesis. Overproduction and deposition of this pigment cause different problems in various industries including agriculture and food. Finding safe tyrosinase inhibitors thus attracts great research interest. The goal of this study is evaluation of inhibitory potencies of some novel synthetic derivatives of tyrosol and raspberry ketone on diphenolase activity of mushroom tyrosinase. The ligands inhibited enzyme activity and compound 4-(2-(4-(hydroxymethyl)-2-methyl-1,3-dioxolan-2-yl)ethyl)phenol (1d) exhibited the most inhibitory potency (77% inhibition, IC50=0.32µmol L-1) via the mixed inhibition mode. This compound was also safe according to the results of in vitro analyses. The enzyme-ligands interactions were theoretically and experimentally investigated using molecular docking and fluorescence quenching approaches, respectively. Modes of quenching and related parameters were also determined and molecular docking data showed that the ligands bind to important sites of the enzyme. These compounds, especially 1d, can be suggested as efficient candidates for further investigations.

Potent Antioxidant and Anti-Tyrosinase Activity of Butein and Homobutein Probed by Molecular Kinetic and Mechanistic Studies.

Butein (BU) and homobutein (HB) are bioactive polyhydroxylated chalcones widespread in dietary plants, whose antioxidant properties require mechanistic definition. They were investigated by inhibited autoxidation kinetic studies of methyl linoleate in Triton™ X-100 micelles at pH 7.4, 37 °C. Butein had kinh = (3.0 ± 0.9) × 104 M-1s-1 showing a chain-breaking mechanism with higher antioxidant activity than reference α-tocopherol (kinh = (2.2 ± 0.6) × 104 M-1s-1), particularly concerning the stoichiometry or peroxyl radical trapping n = 3.7 ± 1.1 vs. 2.0 for tocopherol. Homobutein had kinh = (2.8 ± 0.9) × 103 M-1s-1, pairing the relative BDEOH measured by radical equilibration EPR as 78.4 ± 0.2 kcal/mol for BU and estimated as 82.6 kcal/mol for HB. The inhibition of mushroom tyrosinase (mTYR) by HB and BU was also investigated. BU gives a reversible uncompetitive inhibition of monophenolase reaction with KI' = 9.95 ± 2.69 µM and mixed-type diphenolase inhibition with KI = 3.30 ± 0.75 µM and KI' = 18.75 ± 5.15 µM, while HB was nearly competitive toward both mono- and diphenolase with respective KI of 2.76 ± 0.70 µM and 2.50 ± 1.56 µM. IC50 values (monophenolase/diphenolase at 1 mM substrate) were 10.88 ± 2.19 µM/15.20 ± 1.25 µM, 14.78 ± 1.05 µM/12.36 ± 2.00 µM, and 33.14 ± 5.03 µM/18.27 ± 3.42 µM, respectively, for BU, HB, and reference kojic acid. Molecular docking studies confirmed the mechanism. Results indicate very potent antioxidant activity for BU and potent anti-tyrosinase activity for both chalcones, which is discussed in relation to bioactivity toward protection from skin disorders and food oxidative spoilage.

Evaluation of Rhodiola rosea Root Fraction as a Functional Cosmetic Ingredient

To develop functional cosmetic material using <i>Rhodiola rosea</i>, the biological activities such as anti-oxidant, anti-inflammatory, astringent, anti-tyrosinase, and anti-elastase activity were investigated with methanol, <i>n</i>-hexane, chloroform, ethyl acetate, n-butanol, and water fractions of <i>R. rosea</i> Root. DPPH and ABTS radical scavenging activities of ethyl acetate fraction were increased in a dosedependent manner; the activities were higher than other fractions. The total phenolic content of ethyl acetate fraction also showed a relatively high value of 500.485±4.848 mgGAE/g. The ethyl acetate fraction also significantly decreased LPS-induced NO production and IL-6 secretion compared with untreated control cells at above 5-100 μg/mL concentrations. The astringent activity of ethyl acetate fraction was 94.31% at a concentration of 500 μg/mL, and the activity of ethyl acetate fraction was similar to that of tannic acid. The mushroom tyrosinase inhibition abilities of hexane, ethyl acetate, and butanol were 10.44%, 17.53%, and 14.55%, respectively, at 100 μg/mL. Furthermore, an elastase inhibition rate showed a relatively high effect at 100 μg/mL, 45.46% of inhibition rate in the ethyl acetate and 45.07% of inhibition rate in the butanol fraction. These results indicate that R. rosea Root would be used as a natural material in the functional cosmetic and beauty-food industries.

Exploring the Potential of ω3 Derivatives as Tyrosinase Inhibitors: A Comprehensive Study Combining Experimental, Computational, and Biological Approaches

AbstractIn this work, the inhibitory ability and mechanism of ω3‐nicotinic acid (ω3‐NA) and ω3‐Picolinic acid (ω3‐PA) complexes on the activity of mushroom tyrosinase (MT) were scrutinized for progressing a novel MT inhibitor. The complexes were synthesized. It was shown to have a considerable inhibition on the MT activity and Ki value of ω3‐NA and ω3‐PA on MT equal to 5.2 and 5.1 mM, respectively. ω3‐NA and ω3‐PA inhibited MT with Vmax values in the range of 0.134 mM and 0.14 mM, respectively. The outputs obtained from fluorescence quenching specified that ω3‐NA and ω3‐PA could interact with MT. Especially, the decrease in fluorescence intensity was due to the formation of a ligand‐enzyme complex which was mostly motivated by hydrogen bonding and hydrophobic forces. The presence of ω3‐NA and ω3‐PA altered the structure of MT and reduced the α‐helix of the enzyme. Molecular docking investigation along with molecular dynamics simulation exhibited that ligands‐MT formation is directed by hydrogen binding with Trp136, His263, and Val299 residues. The results highlight that ω3‐NA and ω3‐PA can be considered as possible inhibitors in treating hyperpigmentation via MT enzyme inhibition.

Heterocyclic Compounds as Synthetic Tyrosinase Inhibitors: Recent Advances.

Tyrosinase is a copper-containing enzyme which is widely distributed in nature (e.g., bacteria, mammals, fungi) and involved in two consecutive steps of melanin biosynthesis. In humans, an excessive production of melanin can determine hyperpigmentation disorders as well as neurodegenerative processes in Parkinson's disease. The development of molecules able to inhibit the high activity of the enzyme remain a current topic in medicinal chemistry, because the inhibitors reported so far present several side effects. Heterocycle-bearing molecules are largely diffuse in this sense. Due to their importance as biologically active compounds, we decided to report a comprehensive review of synthetic tyrosinase inhibitors possessing heterocyclic moieties reported within the last five years. For the reader's convenience, we classified them as inhibitors of mushroom tyrosinase (Agaricus bisporus) and human tyrosinase.

Synthesis, in silico modelling, and in vitro biological evaluation of substituted pyrazole derivatives as potential anti-skin cancer, anti-tyrosinase, and antioxidant agents

Twenty-five azole compounds (P1–P25) were synthesised using regioselective base-metal catalysed and microwave-assisted approaches, fully characterised by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and infrared spectra (IR) analyses, and evaluated for anticancer, anti-tyrosinase, and anti-oxidant activities in silico and in vitro. P25 exhibited potent anticancer activity against cells of four skin cancer (SC) lines, with selectivity for melanoma (A375, SK-Mel-28) or non-melanoma (A431, SCC-12) SC cells over non-cancerous HaCaT-keratinocytes. Clonogenic, scratch-wound, and immunoblotting assay data were consistent with anti-proliferative results, expression profiling therewith implicating intrinsic and extrinsic apoptosis activation. In a mushroom tyrosinase inhibition assay, P14 was most potent among the compounds (half-maximal inhibitory concentration where 50% of cells are dead, IC50 15.9 μM), with activity greater than arbutin and kojic acid. Also, P6 exhibited noteworthy free radical-scavenging activity. Furthermore, in silico docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) simulations predicted prominent-phenotypic actives to engage diverse cancer/hyperpigmentation-related targets with relatively high affinities. Altogether, promising early-stage hits were identified – some with multiple activities – warranting further hit-to-lead optimisation chemistry with further biological evaluations, towards identifying new skin-cancer and skin-pigmentation renormalising agents.

Inhibitory Effects of Caulerpa racemosa, Ulva intestinalis, and Lobophora challengeriae on Tyrosinase Activity and α-MSH-Induced Melanogenesis in B16F10 Melanoma Cells.

Melanogenesis involves a synthesis of melanin pigment and is regulated by tyrosinase. The addition of whitening agents with tyrosinase-inhibiting properties in cosmetics is becoming increasingly important. In this study, the ethanolic extracts from twelve seaweeds were assessed for tyrosinase-inhibiting activity using mushroom tyrosinase and melanin synthesis in B16F10 melanoma cells. The highest mushroom tyrosinase inhibition (IC50) was observed with Lobophora challengeriae (0.15 ± 0.01 mg mL-1); treatment was more effective than kojic acid (IC50 = 0.35 ± 0.05 mg mL-1), a well-known tyrosinase inhibitor. Three seaweeds, Caulerpa racemosa, Ulva intestinalis, and L. challengeriae, were further investigated for their ability to reduce melanogenesis in B16F10 cells. The ethanolic extracts of C. racemosa, U. intestinalis, and L. challengeriae showed inhibitory effects by reducing melanin and intracellular tyrosinase levels in B16F10 cells treated with α-melanocyte stimulating hormone in a dose-dependent manner. C. racemosa (33.71%) and L. challengeriae (36.14%) at 25 µg mL-1 reduced melanin production comparable to that of kojic acid (36.18%). L. challengeriae showed a stronger inhibition of intracellular tyrosinase (decreased from 165.23% to 46.30%) than kojic acid (to 72.50%). Thus, ethanolic extracts from C. racemosa, U. intestinalis, and L. challengeriae can be good sources of natural tyrosinase inhibitors and therapeutic or cosmetic agents in the future.

Anti-tyrosinase flavone derivatives and their anti-melanogenic activities: Importance of the β-phenyl-α,β-unsaturated carbonyl scaffold

Flavone derivatives were designed and synthesized based on the hypothesis that flavones containing the β-phenyl-α,β-unsaturated carbonyl (PUSC) scaffold have potential anti-tyrosinase activity. Flavones 1a and 1e inhibited mushroom tyrosinase more potently than kojic acid, and 1e inhibited monophenolase and diphenolase 61- and 28-fold more than kojic acid, respectively. Kinetic studies on mushroom tyrosinase indicated that 1a and 1e competitively inhibit monophenolase and diphenolase, and docking results supported these results. In an in vitro assay using B16F10 murine cells, 1a and 1e inhibited melanin production more potently than kojic acid, and this was attributed to the inhibition of tyrosinase. Furthermore, 1a and 1e strongly scavenged DPPH and ABTS radicals and ROS, which suggested that their antioxidant properties were at least partly responsible for their anti-melanogenic effects. Moreover, flavone 1a also inhibited the gene expressions of the melanogenesis-related genes tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. Our findings that flavone derivatives (i) directly inhibit tyrosinase, (ii) act as antioxidants, and (iii) inhibit the expressions of melanogenesis-related genes suggest their potential use as natural melanogenesis inhibitors. Furthermore, the study confirms that the PUSC scaffold confers anti-tyrosinase activity.

The in vitro cytotoxicity against human melanoma cells, tyrosinase inhibition and antioxidant activity of Grewia tenax leaves extracts

Grewia tenax (Forssk.) Fiori (Malvaceae) grows in the Arabian Peninsula and is used for several medicinal purposes. To characterize the dermatological bioactivities of G. tenaxin terms of its antimelanoma, antityrosinase and antioxidant activities. Cytotoxicity was assessed by cell proliferation and mitochondrial viability assays. Ability to inhibit mushroom tyrosinase and scavenge free radicals were evaluated by an enzymatic and DPPH scavenging microtiter assay, respectively. Phytochemical analyses were carried out using TLC, HPLC-UV and NMR. The chloroform extract shown significant cytotoxic activity in terms of mitochondrial viability (43 ± 14 μg/mL). We identified lupeol and b-sitosterol as the main active components for the tyrosinase inhibitory activity of the hexane extract. Scavenging activity of the DPPH· radical was confined to the water extract. Extracts from this plant have the potential to be used as a base in the development of cosmeceutical products intended to whiten skin or to combat radical-induced physiopathological processes.

In vitro anti-ageing activities of ethanolic extracts from Pink rambutan (Nephelium lappaceum Linn.) for skin applications

Skin ageing is characterized by features such as wrinkles, loss of elasticity, laxity, rough-textured appearance, melasma and freckles. Several researches have focused for preventing, and treating skin ageing by many natural ingredients. This study aimed to assess the anti-ageing activities for anti-skin ageing of the ethanolic extracts of Pink rambutan (PR) (Nephelium lappaceum Linn.) from leaves (L), branches (B), seeds (S), and peels from ripe (R) and young (Y) fruits. The extraction yields of all Pink Rambutan (PR) extracted by the Maceration (M) and the Soxhlet extraction (Sox) using 95% ethanol as a solvent, ranged from 10.62% to 30.63%. Flavonoids were found as the main phytochemicals in almost all the PR extracts. The PR-Y-M and PR-Y-Sox extracts gave the highest total phenolic contents by the Folin-Ciocalteu assay of 67.60 ± 4.38 mgGAE/g, and total flavonoid contents by the modified aluminum chloride colorimetric assay of 678.72 ± 23.59 mgQE/g, respectively. The PR-L-M extracts showed the highest three anti-oxidative activities; the free radical scavenging (SC50 of 0.320 ± 0.070 mg/mL), the lipid peroxidation inhibition (LC50 of 0.274 ± 0.029 mg/mL), and the metal chelation activity (MC50 of 0.203 ± 0.021 mg/mL). All the PR extracts at 0.01 and 0.1 mg/mL showed no cytotoxicity on B16F10 cells, and human skin fibroblasts, respectively. Likewise, the PR-R-Sox extract exhibited the highest anti-melanogenesis on B16F10 cells (52.7 ± 0.9%) and, the mushroom tyrosinase inhibition activity (IC50 of 0.04 ± 0.02 mg/mL), which was significantly comparable to kojic acid (p < 0.05). The PR-Y-Sox extract showed the collagen biosynthesis by the Sirius Red method, and the stimulation of anti-ageing genes (Sirt1 and Foxo1) on human skin fibroblasts by the RT-PCR method, which were similar to standards ʟ-ascorbic acid and resveratrol, respectively. This study suggests that the PR-R-Sox and PR-Y-Sox extracts can be further developed as natural anti-ageing agents for whitening and anti-wrinkle in the cosmetics, cosmeceutical, and pharmaceutical industries.

Natural Melanogenesis Inhibitor, Antioxidant, and Collagen Biosynthesis Stimulator of Phytochemicals in Rice Bran and Husk Extracts from Purple Glutinous Rice (Oryza sativa L. cv. Pieisu 1 CMU) for Cosmetic Application

Oryza sativa L. cv. Pieisu 1 CMU (PES1CMU) has a high anthocyanin content in the colored bran and high phenolic content in the husk. Biologically active compounds in plants are available as dietary supplements and cosmetics. To expand the utilization of natural resources, PES1CMU will be a natural remedy for skin hyperpigmentation and aging. Cell-free tyrosinase inhibition and scavenging assays were used to screen all extracts, including PES1CMU-rice bran oil (RBO), PES1CMU-defatted rice bran (DFRB), and PES1CMU-husk (H). PES1CMU extracts were first examined in IBMX-stimulated B16 cells and H2O2-induced fibroblasts. The results exhibited that PES1CMU-DFRB was the most effective inhibitor of mushroom tyrosinase, intracellular melanin production (fold change of 1.11 ± 0.01), and tyrosinase activity (fold change of 1.22 ± 0.10) in IBMX-stimulated B16 cells. Particularly, PES1CMU-DFRB showed a comparable whitening effect to the standard arbutin with no significant difference (p > 0.05). Moreover, PES1CMU-DFRB and PES1CMU-H demonstrated strong scavenging activities. After accelerated cell aging caused by H2O2 exposure in fibroblasts, the levels of malondialdehyde production in all PES1CMU-treated fibroblasts were comparable with those of standard l-ascorbic acid (p > 0.05). Besides, PES1CMU-DFRB and PES1CMU-H treatment significantly inhibited collagen degradation against MMP-2 compared to l-ascorbic acid-treated cells (p > 0.05). PES1CMU rice-processing wastes (DFRB and H) could become potential natural sources for dermatocosmetic constituents in skin anti-aging and whitening products.

Antioxidant Potential-Rich Betel Leaves (Piper betle L.) Exert Depigmenting Action by Triggering Autophagy and Downregulating MITF/Tyrosinase In Vitro and In Vivo.

Each individual has a unique skin tone based on the types and quantities of melanin pigment, and oxidative stress is a key element in melanogenesis regulation. This research sought to understand the in vitro and in vivo antioxidant and depigmenting properties of betel leaves (Piper betle L.) extract (PBL) and the underlying mechanism. Ethyl acetate fractions of PBL (PBLA) demonstrated excellent phenolic content (342 ± 4.02 mgGAE/g) and strong DPPH, ABTS radicals, and nitric oxide (NO) scavenging activity with an IC50 value of 41.52 ± 1.02 μg/mL, 45.60 ± 0.56 μg/mL, and 51.42 ± 1.25 μg/mL, respectively. Contrarily, ethanolic extract of PBL (PBLE) showed potent mushroom, mice, and human tyrosinase inhibition activity (IC50 = 7.72 ± 0.98 μg/mL, 20.59 ± 0.83 μg/mL and 24.78 ± 0.56 μg/mL, respectively). According to gas chromatography-mass spectrometry, PBL is abundant in caryophyllene, eugenol, O-eugenol, 3-Allyl-6-methoxyphenyl acetate, and chavicol. An in vitro and in vivo investigation showed that PBLE suppressed tyrosinase (Tyr), tyrosinase-related protein-1 and -2 (Trp-1 and Trp-2), and microphthalmia-associated transcription factors (MITF), decreasing the formation of melanin in contrast to the untreated control. PBLE reduced the cyclic adenosine monophosphate (cAMP) response to an element-binding protein (CREB) phosphorylation by preventing the synthesis of cAMP. Additionally, it activates c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (p38), destroying Tyr and MITF and avoiding melanin production. Higher levels of microtubule-associated protein-light chain 3 (LC3-II), autophagy-related protein 5 (Atg5), Beclin 1, and lower levels of p62 demonstrate that PBLE exhibits significant anti-melanogenic effects via an autophagy-induction mechanism, both in vitro and in vivo. Additionally, PBLE significantly reduced the amount of lipid peroxidation while increasing the activity of several antioxidant enzymes in vivo, such as catalase, glutathione, superoxide dismutase, and thioredoxin. PBLE can therefore be employed in topical formulations as a potent skin-whitening agent.