Tyrosinase Activity Research Articles

Synthesis, anti-browning effect and mechanism research of kojic acid-coumarin derivatives as anti-tyrosinase inhibitors

Thirteen kojic acid-coumarin derivatives were synthesized using the principle of molecular hybridization, and their structures were characterized by 1H NMR, 13C NMR, and HRMS. In vitro enzyme inhibition experiments showed that all newly synthesized derivatives have excellent inhibition of tyrosinase (TYR) activity. As a mixed inhibitor, compound 6f has the strongest activity, with an IC50 value of 0.88 ± 0.10 µM. Multispectral experiments have confirmed that the mode of action of compound 6f on TYR was static quenching. In addition, compound 6f formed a new complex with TYR, which increased the hydrophobicity of the enzyme microenvironment, reduced the content of the α-helix in the enzyme, and changed the secondary structure. The experimental results showed that compound 6f effectively inhibited the browning of lotus root slices and had low cytotoxicity. Therefore, compound 6f is believed to have great development potential as a TYR inhibitor in the food industry.

Exploring the effect of butyric acid, a metabolite from periodontopathic bacteria, on primary human melanocytes: An in vitro study

Effects of butyric acid, a bacterial metabolite implicated in periodontitis progression, have never been examined on oral melanocytes. Herein, primary human epidermal melanocytes were used as a model for oral melanocytes. Results show the adverse effects of butyric acid (sodium butyrate; NaB) on them, which comprise marked cytotoxicity at higher concentrations (>1 mM) and robust differentiation at lower nontoxic concentrations. NaB did not alter MITF protein levels; however, it stimulated tyrosinase protein synthesis and inhibited tyrosinase activity, with no changes in cellular melanin. NaB did not affect oxidative stress, although it induced significant levels of the pro-inflammatory cytokine IL-6.

Melanogrit potentiates melanogenesis by escalating cellular tyrosinase activity and MITF levels via pERK inhibition.

Vitiligo is characterized by the development of white patches on the skin either due to the loss of functional melanocytes or perturbations in the melanogenesis pathway. In the present study, we investigated the therapeutic potential of herbo-mineral formulation, Melanogrit in neutralizing the white patches in the skin. The study utilized UPLC/MS-QToF technique to determine the diversified phytochemical profile in Melanogrit. The murine B16F10 cells when treated with Melanogrit underwent morphological changes, including increased angularity, enlarged cell size, and greater dendritic protrusions. To establish an equivalent model to study melanogenesis, we carefully optimized the dosage of α-melanocyte stimulating hormone (αMSH) in B16F10 cells as an alternative to using melanocyte-keratinocyte cocultures. The study determined a sub-optimal dose of αMSH (0.2 nM) in B16F10 cells that does not manifest any measurable effects on melanogenesis. In contrast, Melanogrit when used in conjunction with 0.2 nM αMSH, induced a dose-dependent increase in extracellular and intracellular melanin levels. Melanogrit transcriptionally up-regulated the decisive genes of the melanogenesis pathway, MITF, TYR, and TRP1, which was evident from the increased cellular tyrosine activity. Our findings also demonstrated that Melanogrit ameliorated the MITF protein levels by inhibiting pERK; notably without involving GSK3β in the process. Taken together, our findings strongly suggest that Melanogrit has the potential to stimulate melanogenesis, making it a promising candidate for clinical applications in the treatment of white skin patches that develop in vitiligo patients.

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.

Putrescine Upregulates Melanogenesis Through Modulation of MITF Transcription Factor in B16F1 Mouse Melanoma Cells.

Ageing is a biochemical, metabolic and genetic physiological phenomenon. The suppression of melanin biosynthesis, evident in the greying of the hair, is a hallmark of ageing resulting from translation failure, reduced enzyme activity and cellular senescence. Putrescine, the smallest member of the polyamine family and an organic chemical, is present in living mammalian cells and plays a crucial role in regulating skin melanogenesis. Therefore, the purpose of this study is to explore the effect of putrescine on the signalling pathways of melanogenesis in melanoma cells. Melanin production capacity of putrescine was analysed using a tyrosinase activity assay. To assess the cell viability of B16F1 cells exposed to putrescine, a tetrazolium dye MTT assay was performed. The effect of putrescine on melanin synthesis in the presence of H2O2 was evaluated using various in vitro assays in B16F1 cells. The effect of putrescine on melanin production in B16F1 cells was determined using a specific melanin production assay. Gene expression was analysed using real-time polymerase chain reaction (RT-PCR). Furthermore, the effect of putrescine on the expression of proteins related to melanin production in the cells treated with H2O2 was analysed by immunofluorescence and Western blot analysis. Putrescine increased tyrosinase activity and showed no cytotoxicity in B16F1 cells. In addition, putrescine effectively scavenged H2O2, as shown by the reduction of intracellular H2O2 amounts in 2',7'-dichlorofluorescin diacetate analysis, and promoted melanin production in living cells. The stimulation of melanogenesis by putrescine was attributed to the increased expression of Mitf, Tyr, Trp-1 and Trp-2 genes. Immunofluorescence assays revealed that putrescine enhanced the expression of proteins associated with melanogenesis and upregulated TYR, TRP-1 and TRP-2 via the microphthalmia-associated transcription factor (MITF) and increased the expression of methionine sulfoxide reductases A (MSRA) and B (MSRB) in the cells treated with H2O2, effectively promoting melanogenesis. These results suggest that putrescine can be used to stimulate melanin synthesis. This is the first study to investigate the effect of putrescine on the signalling pathways of melanogenesis in B16F1 melanoma cells. The results confirm that putrescine can promote melanogenesis through the expression of TYR, TRP-1 and TRP-2 via the MITF in cells treated with H2O2. Putrescine can be used exclusively as a cosmetic product to prevent premature greying of hair.

Microwave-assisted extraction of Lawsonia inermis L. leaves: Method validation, optimization, and tyrosinase-stimulating activity

Vitiligo is a long-term skin condition characterized by the development of pale white patches due to a lack of melanin. Lawsonia inermis L. leaves, which contain lawsone, have been explored as a potential alternative treatment for vitiligo. This study aimed to optimize the microwave-assisted extraction of L. inermis leaves and evaluate its ability to stimulate tyrosinase activity, which is relevant to vitiligo treatment. The Box-Behnken design was employed, with three factors being varied: microwave power, time, and cycle. Two responses were monitored: extraction yield and lawsone content. To determine the lawsone content, validated high-performance liquid chromatography was utilized, which demonstrated good linearity, specificity, precision, and accuracy. The optimal conditions that provided the highest extraction yield and lawsone content were then used to evaluate the extract’s ability to stimulate tyrosinase activity. The results revealed that a microwave power of 300 W and a microwave time of 20 s for one cycle yielded an extraction yield of 12.99% ± 0.10% and a lawsone content of 94.85 ± 3.12 mg/g extract. The accuracy of the prediction, with a percent error of less than 10%, confirmed the reliability of the computer program used for data prediction. Furthermore, the extract exhibited significant stimulation of tyrosinase activity, indicating its potential usefulness in vitiligo treatment. The optimal microwave-assisted extraction method identified in this study holds promise for maximizing extraction yield and lawsone content in L. inermis leaves extract. This extract could serve as a basis for developing topical products for the treatment of vitiligo.

Investigation of the whitening activity of ginsenosides from Panax notoginseng and optimization of the dosage form

BackgroundGinsenoside, as an active ingredient in traditional Chinese medicine, has been widely used for skin whitening for several years. Recent research has found that Panax notoginseng has a higher content of ginsenosides compared with the Panax ginseng. Those ginsenosides have promising potential to be developed as skin whitening agents. MethodsWe selected five dammarane ginsenosides isolated from P. notoginseng and their mixtures to investigate the skin lightning activity. Zebrafish embryo model was used for initial screening of the whitening activity. Subsequently, the whitening effect of components was examined and compared via testing the inhibition of melanin and activity of tyrosinase in B16 cells treated with these components. Molecular docking was also applied to investigate the interactions between ginsenosides and tyrosinase. Finally, the most effective saponins were selected for dosage form optimization and the whitening effect of saponin-loaded ethosomes was further demonstrated on the C57BL/6 mouse model. ResultsExperimental results showed that the protopanaxtriol saponins (PTS) were the most potent saponins with a decent safety profile, and the molecule docking results demonstrated that PTS had strong inhibitory ability to tyrosinase. PTS was successfully encapsulated into ethosomes with an encapsulation efficiency of 93%. The PTS ethosome gel could effectively inhibit the melanin production caused by UVB tanning on the back skin of mice. ConclusionThe PTS ethosome gel provides an effective and safe formulation of PTS to whiten the UVB-tanned skin in vivo and could be used as a potential skin whitening agent in the future.

The Effect of Fractional Carbon Dioxide Laser on Melanogenesis in Human Melanocytes and Vitiligo Mouse Models.

Vitiligo is an acquired skin pigmentation disorder, the cause of which is poorly understood. Researchers in this field are dedicated to exploring novel treatments for achieving re-pigmentation. Mice were randomly selected and divided into control, model, and model+laser groups. Evaluate the impact of different levels of carbon dioxide laser irradiation on tyrosinase activity, melanocyte viability, and melanin content. In this study, it was found that the cell viability and melanin content were significantly enhanced in human melanocytes after treatment with different energy densities of fractional carbon dioxide laser. In addition, laser-treated vitiligo mouse models showed mild pathological changes. Therefore, we believe that fractional carbon dioxide laser may be a potential adjunctive modality for treating vitiligo.

Exploring 2-mercapto-N-arylacetamide analogs as promising anti-melanogenic agents: in vitro and in vivo evaluation.

Based on the hypothesis that the 2-mercaptoacetamide moiety chelates the copper ions of tyrosinase, 2-mercapto-N-arylacetamide (2-MAA) analogs were designed and synthesized as potential tyrosinase inhibitors. Four 2-MAA analogs showed low IC50 values ranging from 0.95 to 2.0 μM against mushroom tyrosinase, which was 12-26 times lower than that of kojic acid (IC50 value = 24.3 μM). However, according to a copper ion chelation experiment performed, the 2-MAA analogs did not participate in chelation with copper ions. To identify the mode of inhibition of the 2-MAA analogs, kinetic studies were performed, and the results were supported by docking results. In addition, docking simulation results suggested that the 2-MAA analogs strongly inhibited tyrosinase activity because of the hydrogen bonding of the amide NH group and the hydrophobic interaction of the aryl ring instead of chelation with copper ions. In experiments using B16F10 cells, 2-MAA analogs were shown to inhibit melanin production by inhibiting cellular tyrosinase activity. Western blotting showed that in addition to directly inhibiting tyrosinase activity, analog 7 also has an anti-melanogenic effect by inhibiting the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. The 2-MAA analogs showed no appreciable cytotoxicity against HaCaT and B16F10 cells, making them suitable for dermal applications. In a depigmentation experiment using zebrafish embryos, analogs 1 and 2 showed more potent depigmentation effects than kojic acid even at 1000 times lower concentration than that of kojic acid. These results suggest that the 2-MAA analogs are promising anti-melanogenic agents that can inhibit most tyrosinases in various species.

Potential Beneficial Effects of Salvianic Acid A and Salvianolic Acid B in Skin Whitening

Objective Natural product-derived biomaterials are highly desired as possible ingredients in cosmetics, as they are often safe and effective. Salvianic acid A (SAA) and salvianolic acid B (SAB) are the primary water-soluble ingredients of Salvia miltiorrhiza Bunge ( Lamiaceae). These compounds have extensive applications as both effective and biocompatible bioactive agents for the treatment of various diseases including cardiovascular disorders, liver ailments, and neuroprotection. This study aimed to evaluate the skin-whitening effects of SAA and SAB on co-cultured human melanoma A375 cells and human keratinocytes HaCaT cells, with the intention of investigating their potential as cosmetic ingredients. Methods First, we assessed the SAA and SAB's efficacy on cells proliferation using MTT assay, as well as their inhibition on intracellular tyrosinase (TYR) activity. Next, we evaluated their effects on the mRNA expression levels of TYR and its related proteins. Furthermore, the whitening efficacy of SAA and SAB was assessed by observing the decrease in melanin content in treated human amalignant melanoma A375 and human keratinocyte HaCaT cells. Results Both SAA and SAB inhibited the activity of TYR and decreased the mRNA expression of TYR-related proteins, thereby inhibiting melanin synthesis. Conclusion Our results suggest that both SAA and SAB can be applied as natural and novel cosmetics materials having a whitening function, which could be beneficial in the cosmeceutical industry.

First report of piperidone extracts as tyrosinase and α-glucosidase inhibitors from fruits of Piper retrofractum

Importance of the work: Piper retrofractum is used as a spice. This report is the first to identify tyrosinase and α-glucosidase inhibitors extracted from this plant. Objectives: To separate and identify the bioactive compounds from the fruits of P. retrofractum and to evaluate their tyrosinase and α-glucosidase inhibition activities. Materials & Methods: The EtOAc extract was isolated and purified using various chromatographic techniques. The structures of isolated compounds were confirmed based on their spectroscopic data. The tyrosinase and α–glucosidase inhibition activities of the isolated compounds were assessed based on a colorimetric method, using kojic acid and acarbose, respectively, as positive controls. Results: Seven known compounds were identified, named methyl piperate (1), guineensine (2), piperine (3), N-feruloyltyramine (4), (3S, 4S)-4-chloro-3-hydroxy-2-piperidin-2-one (5), 3-chloro-4-hydroxy-2-piperidone (6) and 3α,4α-epoxy-2-piperidone (7). Piperidones 5 and 6 showed tyrosinase inhibition with concentration at 50% inhibition (IC50) values of 4.91 mM and 11.0 mM, respectively, whereas the alkylamides 1–3 and phenylpropanamide 4 were not active. On the other hand, only phenylpropanamide 4 was active against maltase and sucrase with IC50 values of 0.28 mM and 0.5 mM, respectively. Piperidone 5 showed weak inhibition against both maltase and sucrase α-glucosidases, while the piperidones 6 and 7 exhibited weak inhibition against sucrase α-glucosidases. Main finding: The piperidones were more active against tyrosinase than piperine, which is representative metabolite from this plant. Further study on the inhibitory mechanism may lead to suitable applications of the extract in cosmetics.

SIRT7 Inhibits Melanin Synthesis of PIG1 and PIG3V by Suppressing the Succinylation of EZR.

Vitiligo is an autoimmune disease characterized by loss of skin pigmentation and currently has no effective treatment. This study aimed to investigate the function of SIRT7, being an important desuccinylase mediating multiple disease progression, and its mechanism in vitiligo progression. Normal human melanocytes (NHM) PIG1 and vitiligo human melanocytes (VHM) PIG3V were utilized in this research. The role of sirtuin 7 (SIRT7) and Ezrin (EZR) on melanin synthesis was investigated by detecting tyrosinase activity, melanin content, α-MSH levels, and the protein levels of melanin-related markers. The function of EZR was identified via rescue experiments, while the underlying mechanism was investigated via bioinformatic analysis, co-immunoprecipitation (co-IP), immunoprecipitation (IP), and Western blot techniques. Results showed that only SIRT7 was highly expressed in vitiligo human melanocytes, where knockingdown SIRT7 translated into increased melanin synthesis in melanocytes. Mechanistically, SIRT7 knockdown promoted the succinylation of EZR at the Lys (K)60 site. Moreover, overexpressing EZR induced higher melanin synthesis in melanocytes, while its knocking down exerted the opposite effect by inhibiting SIRT7 knockdown-induced melanin synthesis. SIRT7 inhibited melanin synthesis in melanocytes by suppressing the succinylation of EZR. These findings are envisaged to provide a novel theoretical basis for vitiligo treatment.

Natural products as tyrosinase inhibitors.

Tyrosinase is a crucial copper-containing enzyme involved in the production of melanin. Melasma, age spots, and freckles are examples of hyperpigmentation diseases caused by excess production of melanin. Inhibiting tyrosinase activity is a crucial method for treating these disorders along with various applications such as cosmetics, food technology, and medicine. Natural products have proven a rich source of tyrosinase inhibitors, with several molecules from plant, marine, and microbial sources showing potential inhibitory action. This chapter provides a complete overview of natural compounds that have been found as tyrosinase inhibitors, with emphasis on their structures, modes of action, and prospective applications.

Skin protective effect of Indian gooseberry and barley sprout complex on skin dryness, wrinkles, and melanogenesis by cell models.

UV radiation is a major factor contributing to DNA damage in skin cells, including stem cells and mesenchymal stem cells, leading to the depletion of these crucial cells. This study examined whether a mixture of Indian gooseberry and barley sprout (IB) could inhibit UVB irradiation and 3-isobutyl-1-methylxanthine (IBMX)-induced photoaging and oxidative stress in the skin using HaCaT, Hs27, and B16F10 cells. The moisturizing-related factors, the collagen synthesis-related c-Jun N-terminal kinase (JNK)/c-Fos/c-Jun/matrix metalloproteinases (MMPs) pathway, and the melanogenesis-related cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP-responsive binding protein (CREB)/melanocyte inducing transcription factor (MITF)/tyrosinase-related protein (TRP)/tyrosinase activation pathways were analyzed in vitro by an enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot analysis. The IB complex increased the hyaluronic acid and sphingomyelin levels and the collagenase inhibitory activity, enhanced hydration-related factors, including collagen, hyaluronic acid synthase (HAS), elastin, long chain base subunit 1 (LCB1) (serine palmitoyltransferase; SPT), and delta 4-desaturase sphingolipid 1 (DEGS1), modulated the inflammatory cytokines levels, antioxidant enzyme activities and the NF-κB/MMPs/cyclooxygenase-2 (COX-2) pathway in UVB-irradiated HaCaT cells, and inhibited wrinkle formation by down-regulation of the JNK/c-Fos/c-Jun/MMP pathway and up-regulation of the transforming growth factor-β receptor I (TGFβR1)/small mothers against decapentaplegic homolog (Smad3)/procollagen type І pathway in UVB-irradiated Hs27 cells. Moreover, the IB complex prevented melanin production by down-regulating the PKA/CREB/MITF/TRP-1/TRP-2 pathway in IBMX-induced B16F10 cells. These findings suggest that the IB complex has the potential to serve as a safeguard, shielding the skin from UVB radiation-induced photo-damage.

Molecular understanding of the therapeutic potential of melanin inhibiting natural products.

With the development of society and the improvement of people's living standards, there is an increasing demand for melanin-inhibiting products that prioritize health, safety, and efficacy. Therefore, the development of natural products that can safely and efficiently inhibit melanin synthesis is of great social significance and has significant market potential. In this paper, by reviewing the literature reported in recent years, we summarized the natural products with inhibition of melanin synthesis effects that have been put into or not yet put into the market, and classified them according to the chemical groups of their compounds or the extraction methods of the natural products. Through the summary analysis, we found that these compounds mainly include terpenoids, phenylpropanoids, flavonoids and so on, while the natural product extracts mainly include methanol extracts, ethanol extracts, and aqueous extracts. Their main inhibition of melanin synthesis mechanisms include: (1) direct inhibition of tyrosinase activity; (2) down-regulation of the α-MSH-MC1R, Wnt, NO, PI3K/Akt and MAPK pathways through the expression of MITF and its downstream genes TYR, TRP-1, and TRP-2; (3) antioxidant; (4) inhibition of melanocyte growth through cytotoxicity; (5) inhibition of melanosome production and transport. This paper provides an in-depth discussion on the research progress of whitening natural products and their market value. The aim is to offer guidance for future research and development of natural skin whitening products.

Marine resources compound with melanogenic regulatory properties: Especially seagrass, seaweed, and marine sponges as an anti-melanogenic activity

Tyrosinase is a rate-limiting enzyme that is essential for the synthesis of melanin and controls pigmentation in the skin. The most common strategy in cosmeceutical products for skin lightening is the suppression of tyrosinase. Marine substances contain a variety of unique chemical compounds that have the potential to develop into new bioactive compounds as future medications for skin hyperpigmentation therapy. In this review, we summarize 55 compounds from marine resources that have been identified as active in inhibiting tyrosinase enzyme activity from research studies published up to April 2023. Those substances are classified to be very strong, strong, and moderate inhibit tyrosinase activity and melanin biosynthesis. Based on the IC50 value, there are 12 compounds that act as potential anti-melanogenic agents. 7-phloroeckol isolated from Ecklonia cava has the highest tyrosinase enzyme inhibitory activity with an IC50 value of 0.85 μM, while Arenarol isolated from Dysidea arenaria has the most active properties in reducing the synthesis of melanin with an IC50 value of <3 μM on B16 melanoma cells. We propose to present a new perspective on the discovery of metabolites from seagrasses, seaweeds, and marine sponges that can be applied as lead compounds in developing medications for anti-hyperpigmentation therapy through this review.

Peptide and peptidomimetic tyrosinase inhibitors.

Melanin, which is produced by melanocytes and spread over keratinocytes, is responsible for human skin browning. There are several processes involved in melanogenesis, mostly prompted by enzymatic activities. Tyrosinase (TYR), a copper containing metalloenzyme, is considered the main actor in melanin production, as it catalyzes two crucial steps that modify tyrosine residues in dopaquinone. For this reason, TYR inhibition has been exploited as a possible mechanism of modulation of hyper melanogenesis. There are various types of molecules used to block TYR activity, principally used as skin whitening agents in cosmetic products, e.g., tretinoin, hydroquinone, azelaic acid, kojic acid, arbutin and peptides. Peptides are highly valued for their versatile nature, making them promising candidates for various functions. Their specificity often leads to excellent safety, tolerability, and efficacy in humans, which can be considered their primary advantage over traditional small molecules. There are several examples of tyrosinase inhibitor peptides (TIPs) operating as possible hypo-pigmenting agents, which can be classified according to their origin: natural, hybrid or synthetically produced. Moreover, the possibility of variating their backbones, introducing non-canonical amino acids or modifying one or more peptide bond(s), to obtain peptidomimetic molecules, is an added value to avoid or delay proteolytic activity, while the possibility of conjugation with other bioactive peptides or organic moieties can bring other specific activity leading to dual-functional peptides.

Multi-Strain Probiotics Enhance the Bioactivity of Cascara Kombucha during Microbial Composition-Controlled Fermentation.

Kombucha is a widely consumed fermented tea beverage with diverse health benefits. In a previous study, we demonstrated that the use of cascara as a substrate results in a special kombucha beverage with high bioactivity. Traditional kombucha fermentation using a symbiotic culture of bacteria and yeast (SCOBY) can lead to inconsistent product quality because of the lack of control over microbial composition. We successfully isolated and identified yeast and bacteria, including Saccharomyces cerevisiae, Komagataeibacter rhaeticus, and Lactobacillus brevis that are appropriate starter cultures for cascara kombucha fermentation. We also demonstrated that a supplementation with lactic acid bacteria (LAB) and a mixture of S. cerevisiae and K. rhaeticus resulted in higher total polyphenol and flavonoid content of cascara kombucha compared with the traditionally fermented product using SCOBY as the inoculum. The free radical scavenging activity, inhibitory effects on α-amylase, tyrosinase activity, and antibacterial properties of cascara kombucha were also enhanced as a result of LAB supplement. These findings provide valuable insights into the controlled microbiological composition required for the fermentation of cascara kombucha, thereby ensuring consistent quality and enhanced bioactivity of the product. Further, the use of cascara as a substrate for kombucha production not only offers various health benefits and biological effects, but also repurposes by-products from the coffee industry, which contributes to sustainable development and is eco-friendly.

Characterization and tyrosinase activities of a mixture of β-sitosterol and stigmasterol from Bauhinia rufescens Lam

Background: Phytosterols are steroid compounds present in plants that are similar to cholesterol in structure and functions. In this work, stem bark of Bauhinia rufescens was extracted with petroleum ether.
 Objective: This work aims to determine anti-tyrosinase activities of a mixture of β-sitosterol and stigmasterol from the stem bark B, rufescens for the treatment of dermatological disorders.
 Methods: This work is presenting isolation, characterization and anti-tyrosinase activities of a mixture of β-sitosterol and stigmasterol from the stem bark B. rufescens. The extract was subjected to chromatographic techniques to afford a phytosterol identified as a mixture of β-sitosterol and stigmasterol based on GC-MS, IR, 1HNMR and 13CNMR data.
 Results: The phytosterol isolated showed inhibition of tyrosinase activity at 57.1%±0.03 as compared to kojic acid with 85.0% ± 0.01 (sample concentrations of 0.1 mg/mL).
 Conclusion: The finding of this study revealed that, the mixture of β-sitosterol and stigmasterol has potential to be developed as tyrosinase inhibitors for the treatment of dermatological disorders.

An activity of flavonoid derived compounds from Medinilla speciosa as anti-hyperpigmentation against tyrosinase proteins with in silico methods

Parijoto (Medinilla speciosa), a typical plant from Indonesia, contains flavonoid compounds as antioxidants. It is able to depigment skin by inhibiting tyrosinase activity during melanogenesis, or melanin formation. Melanogenesis occurs through UV light exposure; it stimulates ROS production and triggers the formation of free radicals and melanogenesis. If not prevented, it will have negative impacts on health. Currently, there is no further research regarding the existence of flavonoid compound derivatives found in parijoto fruit. The aim of this research is to initially identify potential flavonoid derivative compounds as tyrosinase inhibitors using in silico methods. The results can be used as an initial reference for making products based on natural ingredients with minimal side effects. This research uses a bioinformatics approach with the molecular docking method of ligands towards proteins. The stages in this research include: downloading and preparing receptors and ligands; docking with Autodock Vina; visualization of results with Biovia Discovery Studio; data analysis; and discussion. The analysis is carried out by looking at the affinity energy values and complex conformation between the receptor-ligand. The results show flavonoid derivative compounds have the potential to act as tyrosinase inhibitors, as proven by compounds interactions with the active site of tyrosinase to produce the amino acid residues phenylalanine, proline, asparagine, arginine, and histamine. Produce respective affinity energy values, namely -8.9; -7.7; -7.6; -7.5; -7.5; and 7.4 kcal/mol for chalcone, catechin, flavonol, flavanol, flavone, and flavonone compounds. Meanwhile, the comparison compound used is kojic acid, with an affinity energy of -5.5 kcal/mol.