Anti-tyrosinase Activity Research Articles

Enzyme inhibitory, antioxidant and anti-inflammatory activities of Anabasis articulata phenolic-rich extract; in vitro, in vivo, and in silico studies

The present study aimed at characterizing the phenolic composition of the aqueous extract from Anabasis articulata and its biological properties, in terms of in vitro antioxidant, enzyme inhibitory, and in vivo anti-inflammatory effects. The phytocomplex was investigated by HPLC-DAD analysis, whereas total phenolics, tannins and flavonoids using spectrophotometric methods. The antioxidant property of the extract was determined applying four assays (i.e. total antioxidant capacity, reducing power, DPPH, and β-carotene-linoleic acid bleaching). The enzymatic inhibitory function was evaluated against tyrosinase and acetylcholinesterase, whereas toxicological and anti-inflammatory aspects through in vivo evaluations. More in detail, twenty-one specific phenolic compounds were successfully detected, identified, and quantified in the plant extract, which showed considerable antioxidant potential. The aqueous preparation also revealed a high anti-tyrosinase and anti-acetylcholinesterase activity. In particular, an in-silico prediction analysis, by molecular docking approach, was performed to understand which plant metabolite from A. articulata could be potentially responsible for acetylcholinesterase inhibition, favoring the identification of putative new compounds useful for the treatment of neurodegenerative diseases. All the present evidence could partially explain and justify the therapeutic efficacy of the Algerian traditional medicine linked to the application of A. articulata aqueous extract.

Anti-elastase, Anti-tyrosinase, and Anti-inflammatory Activities of Three Compounds Isolated from Psorospermum aurantiacum: In Silico and In Vitro Assays

Anti-elastase, Anti-tyrosinase, and Anti-inflammatory Activities of Three Compounds Isolated from Psorospermum aurantiacum: In Silico and In Vitro Assays

Antityrosinase activity and LC-MS/MS analysis of optimized ultrasound-assisted condition extracts and fractions from strawberry tree (Arbutus unedo L.).

Investigation of utilization possibilities of natural sources has been an important area for research. Tyrosinase inhibitory activity plays a key role in food and medicine industry. Strawberry tree (Arbutus unedo), a widely distributed plant among Mediterranean countries, possess fruits and leaves with rich bioactive phytochemicals, especially polyphenolic compounds. In this study, we aimed to investigate the antityrosinase activity of the fruit and leaf extracts of the plant, and to determine the phenolic compounds that contribute to the antityrosinase activity. In this regard, we evaluated the effect of solvent composition on the extraction of phenolic compounds from A. unedo and on its antityrosinase activity using a simplex centroid design approach, and used chromatographic and LC-MS/MS techniques. The leaf extracts prepared using EtOH:water (50:50) provided higher TPC (456.39 mg GAE/g extract) and acetone:EtOH:water (33:33:33) provided higher TFC (56.15 mg QE/g extract) values than of fruit extracts. LC-MS/MS analysis revealed 23 phenolic/flavonoid compounds in leaf extracts (L1-8), and major metabolites were detected as quercitrin, quinic acid, catechin, tannic acid, isoquercitrin, gallic acid, and ellagic acid. Among the leaf extracts, L3 (aceton:water, 50:50) exhibited 72.01% tyrosinase inhibition at 500 μg/mL. After fractionation studies guided by antityrosinase activity, its subfraction L3-Fr2 exhibited 40.06% inhibition at 50 μg/mL concentration (IC50: 146 ± 7.75 μg/mL), and catechin (113.19 mg/g), tannic acid (53.14 mg/g), ellagic acid (22.14 mg/g), gallic acid (10.27 mg/g), and epicatechin gallate (8.65 mg/g) were determined as major metabolites. Its subfraction L3-Fr2-sub7 exhibited better antityrosinase activity (IC50: 206.23 ± 9.87 μg/mL), and quantitative analysis results revealed the presence of tannic acid (127.40 mg/g), gallic acid (13.96 mg/g), ellagic acid (7.66 mg/g), quercetin-3-O-glucuronide (5.06 mg/g), and quinic acid (3.2 mg/g) as major metabolites, and correlation analysis showed that ellagic acid and quinic acid were positively correlated with antityrosinase activity.

Phytochemical profiling, antioxidant, and tyrosinase inhibitory potential of the Acacia cyclops trunk bark: in vitro combined with in silico approach.

The aim of this study was to analyze the phytochemical profile of Acacia cyclops trunk bark ethyl acetate extract using LC-tandem mass spectrometry for the first time, along with evaluating its antioxidant and anti-tyrosinase properties. Consequently, we determined the total phenolic and flavonoid contents of the extract under investigation and identified and quantified 19 compounds, including phenolic acids and flavonoids. In addition to assessing their antioxidant potential against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-[3-ethylbenzothiazoline-6-sulfonic] acid) assays, in vitro and in silico studies were conducted to evaluate the tyrosinase inhibitory properties of the A. cyclops extract. The ethyl acetate trunk bark extract exhibited a substantial total phenolic content and demonstrated significant antioxidant activity in terms of free radical scavenging, as well as notable tyrosinase inhibitory action (half-maximal inhibitory concentration [IC50] = 14.08 ± 1.10 μg/mL). The substantial anti-tyrosinase activity of the examined extract was revealed through molecular docking analysis and druglikeness prediction of the main selected compounds. The findings suggest that A. cyclops extract holds promise as a potential treatment for skin hyperpigmentation disorders.

Unveiling the molecular mechanisms of pigmentation control in Queen Loach, Botia dario (Hamilton, 1822): Insights from sesame seed and marigold-induced antityrosinase effects.

Fish pigmentation study can reveal understandings in dermatological research based on functional genomics. Cultured ornamental fish becomes dull coloured and antityrosinase activity through sesame seed may enhance skin colour, which has not been studied. Botia dario is an indigenous fish, having ornamental and aesthetic value and can be studied as a model for fish pigmentation genetics. In this study, fish specimens were fed with 15% marigold petal meal along with 5, 10 and 15% w/w sesame seed in diet. Pigmentation genes, that is, tyr, tyrp1a, asip1, gnaq, kitlga, mc1r, mitf, pax7a, rab38, slc7a11, sox9a, sox10, csf1r, bcdo2 and gsta2 in skin and immunogens, that is, il20, nramp, tlr9 and trail in kidney were studied. Gene expression in tissues revealed enhanced pigmentation and immunity as well as the role of tyr, tyrp1a and asip1 in pigmentation. Immunogenes and blood parameters confirmed the best pigmentation diet. Colorimetric analysis also showed the enhancement of pigmentation. Insights from sesame seed and marigold-induced antityrosinase effects will be applied in aquaculture to develop natural, dietary formulations that will enhance pigmentation in ornamental fish, leading to improved skin colour and market value.

Multidirectional research for the therapeutic potential of Phlomoides molucelloides (Bunge) Salmaki: LC-MS/MS, antioxidant, enzyme inhibition, and antiproliferative characteristics

Medicinal plants offer natural cures and inspire modern medicine's development. This study examined the antioxidant, enzyme-inhibitory, and antiproliferative activities of various extracts obtained from aerial and root fragments of Phlomoides molucelloides (Bunge) Salmaki. The extracts' overall phenolics, flavonoids, and compounds were defined using colorimetric and LC-MS/MS analyses. The highest total phenolic and flavonoid content was measured in the methanol and infusion extracts of the aerial fragments, with 102.21 mg RE/g and 51.33 mg GAE/g, respectively. Most compounds were defined as flavonoids, predominantly as apigenin and quercetin glycosides. Methanol, 70 % methanol, and infusion extracts from aerial parts had the highest antioxidant activity determined by DPPH, ABTS, CUPRAC, FRAP, metal chelation, and phosphomolybdenum analyses. Moreover, the methanol extract of the roots had the highest anti-acetylcholinesterase, anti-butyrylcholinesterase, and anti-glucosidase activities. The dichloromethane extracts of the roots displayed the highest anti-tyrosinase and anti-amylase activities. The antiproliferative activity of the extracts was investigated against MDA-MB-231, MCF-7, and HeLa cell lines. The lowest IC50 value (875.7 µg/mL) was computed for the methanol extract of the aerial part on the MCF-7 cell line at the 48th h. The findings showed that P. molucelloides extracts may offer a promising therapeutic approach due to their rich bioactive content.

Assessment of Anti-tyrosinase, Antioxidant and Cytotoxic Activities of Trigonostemon reidioides Extracts on Mouse Fibroblast (L929) Cells

Assessment of Anti-tyrosinase, Antioxidant and Cytotoxic Activities of Trigonostemon reidioides Extracts on Mouse Fibroblast (L929) Cells

Chemical composition and biological activities of essential oil of the Malaysian endemic Syzygium variolosum (King) Chantar. & J.Parn

This study was designed to investigate the chemical composition of the essential oil of Syzygium variolosum (King) Chantar. & J.Parn. and their cytotoxicity, acetylcholinesterase, antityrosinase, and anti-inflammatory activities. In total, 32 chemical components were identified in the essential oil, which made up 98.9%. The essential oil is mainly composed of β-elemene (20.2%), bicyclogermacrene (13.5%), viridiflorol (11.1%), globulol (8.6%), and selin-11-en-4α-ol (5.3%). Acetylcholinesterase, antityrosinase, and anti-inflammatory activities were evaluated with the Ellman method, mushroom tyrosinase, and lipoxygenase enzymes, respectively, while cytotoxicity was assessed using an MTT assay. The results showed that essential oil gave significant percentage inhibition (I%: acetylcholinesterase 35.2%, antityrosinase 42.5%, lipoxygenase 48.6%). Furthermore, the essential oil exhibited cytotoxicity against three cancer cell lines, HepG2, MCF7, and A549, with IC50 values ranging from 90.2 to 95.2 μg/mL. The current study highlights the potential of the use of essential oils as an alternative to the development of pharmaceutical antichemopreventives or cosmetics.

Exploring the pharmacological significance of Murraya koenigii (L.) Spreng: Insights from North-East India

Murraya koenigii (L.) Spreng., is a renowned medicinal and aromatic plant having antimicrobial and broad biological activities. In the present study, the essential oil chemical profile of the leaf and floral part were analysed using GC-FID and GC-MS, and the antimicrobial activities were determined by disk diffusion assay. The scientific analysis revealed α-pinene (40.41%) was the major compound of leaf essential oil (MKL) followed by sabinene (29.66%), β-pinene (7.92%), caryophyllene (4.24%), limonene (3.39%), terpinen-4-ol (3.25%), γ-terpinene (2.63%), terpinolene (1.58%), linalool (1.32%), along with other trace components. The floral part (MKF) contains the compounds α-pinene (74.02%) as the major compound followed by β-pinene (7.17%), sabinene (5.72%), limonene (4.19%), β-myrcene (1.98%), γ-terpinene (1.47%) and terpinen-4-ol (1.41%) along with other trace compounds. The MIC result revealed essential oil showed effectiveness against Escherichia coli (40 μg/mL), Micrococcus luteus (80 μg/mL), Aspergillus fumigatus (60 μg/mL) and Aspergillus brasiliensis (80 μg/mL) for MKL while MKF did not exhibit potent antimicrobial activities. The essential oils revealed potent antioxidant potential as determined by DPPH method with IC50 values of 14.02 μL/mL (MKL) and 5.45 μL/mL (MKF) and the ABTS method with IC50 values of 5.07 μL/mL and 8.38 μL/mL in MKL and MKF respectively as compared to that of the standards. The essential oils revealed potent antidiabetic activity with 6.02 μL/mL (MKL) and 8.18 μL/mL (MKF) as that of the standard. However, both MKL and MKF were not much effective in protease inhibitory activity and anti-tyrosinase activity. The study results exhibited a potent bioactivity profile and revealed many new utilization aspects of this essential oil.

Enhancing the Antioxidant, Anti-tyrosinase and Anti-elastase Activity of Pigmented Rice Extracts by Sonication, Heating, Enzyme Digestion and Fermentation

In the modern cosmetics industry, there exists a major trend for replacement of synthetic chemicals with plant-based ingredients in skincare formulation. This research aimed to assess the efficiency of different methods to extract bioactive compounds (as measured by total phenolic content; TPC and total flavonoid content; TFC) responsible for three important cosmeceutical properties (antioxidation, anti-tyrosinase, and anti-elastase) from selected rice grains. The grains of two varieties of purplish-black rice (Neaw Leum Pua; NLP) and black rice (Hom Nil; HN) were extracted with phosphate buffered saline (PBS) and then supplementary treated with sonication, heating, and proteolytic enzyme digestion or fermented with Aspergillus niger. The results showed that sonication slightly enhanced TPC and TFC, but significantly increased antioxidant capacity and anti-tyrosinase activity. The high temperature of 60℃ and 100℃ significantly increased antioxidant capacity based on FRAP assay but reduced that based on DPPH radical scavenging assay. Anti-tyrosinase activity was enhanced by high temperature but that of anti-elastase was inhibited. The addition of papain to the seed extracts slightly enhanced anti-elastase and anti-tyrosinase activity. Notably, fermented rice grains exhibited much greater yields of TPC and TFC, and higher biochemical activities than other methods. The fermented rice exhibited the highest TFC after 3 days; the highest TPC, antioxidant capacity, and tyrosinase inhibition after 6 days; and the highest elastase inhibition activity after 9 days. Therefore, fermentation was the most promising technique to enhance all three desirable properties for cosmetic ingredients when pigmented rice was used as the raw material.

Isolation of four new monoterpenes from Ailanthus altissima (mill.) Swingle and their enzyme inhibitory effects

A phytochemical study of the ethanol extract from Ailanthus altissima (Mill.) Swingle leaves resulted in the isolation of four new monoterpenoids (1–3, 5). The structures were elucidated using HRESIMS data, NMR spectroscopic data, quantum chemical calculations for NMR and ECD, and custom DP4+ probability analysis. Additionally, the absolute configuration of sugar was determined by acid hydrolysis. Compounds 1–4 are cyclogeraniane monocyclic monoterpenes, while compound 5 contains an acyclic mycrane monoterpenes skeleton. Anti-tyrosinase, anti-acetylcholinesterase, and anti-butyrylcholinesterase activities were tested. Compound 1 showed notable anti-acetylcholinesterase activity, and compound 3 exhibited significant inhibitory effects on anti-tyrosinase activity. Furthermore, the potential binding sites of compounds 1 and 3 were predicted by molecular docking.

Employing fruit juices to hydrolyze edible bird's nest and enhance the antioxidant, anti-tyrosinase, and wound-healing activities of the hydrolysates

Enzymatic hydrolysis of edible bird's nest (EBN) has attracted great interest in both scientific and commercial fields due to the enhancement of solubility and nutraceutical values. The present study attempted to investigate the hydrolysis of EBN with papaya (Carica papaya L.), pineapple (Ananas comosus (L.) Merr.), and cantaloupe (Cucumis melo L.) juices as well as two commercial enzymes papain and bromelain. Our analysis revealed that EBN hydrolysis with pineapple juice and bromelain produced a degree of hydrolysis (DH) value of approximately 27 % while it was about 25 % for the hydrolysis with cantaloupe juice and 22 % for the hydrolysis with papaya juice and papain after 4 h of treatment. When EBN was digested by fruit juices and enzymes, the protein solubility and free sialic acid content were increased and the highest values were achieved for EBN hydrolysis with pineapple juice and bromelain (estimately 11 mg/mL of soluble protein and 18 g/kg of free sialic acid). The ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase capacities were higher in the EBN hydrolysates by papaya juice (IC50 of 0.034, 0.108, and 0.419 mg/mL, respectively), pineapple juice (IC50 of 0.025, 0.045, and 0.190 mg/mL, respectively), and cantaloupe juice (IC50 of 0.031 mg/mL, 0.056, and 0.339 mg/mL, respectively) than in the hydrolysates by unhydrolyzed EBN (IC50 of 0.094, 0.366, and 1.611 mg/mL, respectively). An improvement in ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase abilities was also observed for the hydrolysates by papain (IC50 of 0.041, 0.129, and 0.417 mg/mL, respectively) and bromelain (IC50 of 0.025, 0.069, and 0.336 mg/mL, respectively) but in a lesser extent as compared to the hydrolysates by respective papaya and pineapple juices. Noticeably, the EBN hydrolysates by fruit juices remarkably enhanced the wound closure in human fibroblasts by about 1.4–1.8 times after 24 h of treatment whereas this property was insignificant in the hydrolysates by enzymes. As papaya, pineapple, and cantaloupe juices are easily obtainable and have pleasant flavors, our results provide a possible method to hydrolyze EBN and apply the resultant hydrolysates in functional food products.

Biochemical and In Silico Studies on Triazole Derivatives as Tyrosinase Inhibitors: Potential Treatment of Hyperpigmentation Related Skin Disorders.

Tyrosinase is a versatile, glycosylated copper-containing oxidase enzyme that mainly catalyzes the biosynthesis of melanin in mammals. Its overexpression leads to the formation of excess melanin, resulting in hyperpigmentary skin disorders, such as dark spots, melasma, freckles, etc. Therefore, inhibition of tyrosinase is a therapeutic approach for the treatment of hyperpigmentation. The current study focused on evaluating tyrosinase inhibitory activities of triazole derivatives 1-20, bearing different substituents on the phenyl ring. 17 derivatives have shown a potent tyrosinase inhibition with IC50 values between 1.6 to 13 μM, as compared to the standard drug, i.e., kojic acid (IC50 = 24.1 ± 0.5 μM). Particularly, compounds 11 and 15 displayed 12 times more potent inhibitory effects than the kojic acid. The structure-activity relationship revealed that substituting halogens at the C-4 position of the benzene ring renders remarkable anti-tyrosinase activities. Compounds 1-3 and 8 showed a competitive type of inhibition, while compounds 5, 11, and 15 showed a non-competitive mode of inhibition. Next, we performed molecular docking analyses to study the binding modes and interactions between the ligands (inhibitors) and the active site of the tyrosinase enzyme (receptor). Besides this, we have assessed the toxicity profile of inhibitors on the BJ human fibroblast cell line. The majority of the newly identified tyrosinase inhibitors were found to be noncytotoxic. The results presented herein form the basis of further studies on triazole derivatives as potential drug leads against tyrosinase-related diseases.

The Antityrosinase Activity of Mitragyna speciosa Korth Leaf Ethanolic Extract

The kratom plant (Mitragyna speciosa Korth) is a the plant that is traditionally used to soften the skin. Kratom leaves have very strong antioxidant activity so they are predicted also to have anti-tyrosinase activity. The potential inhibition of tyrosinase enzyme activity is thought to come from the content of flavonoid compounds, polyphenols, steroids, tannins, and quinones. This research aims to determine the tyrosinase inhibitory activity of ethanol extract of M. speciosa leaves. The inhibitory activity of the tyrosinase enzyme using L-DOPA as substrate and kojic acid as positive control. Antityrosinase testing was carried out by in vitro method using UV-vis spectrophotometer through determination of IC50 value. The results of the antityrosinase activity test of ethanol extract of M. speciosa leaves showed an IC50 value of 2117.708 ppm. The ethanol extract of M. speciosa leaves is scientifically proven to have antityrosinase activity with a weak category.

Unveiling the tyrosinase inhibitory potential of phenolics from Centaurium spicatum: Bridging in silico and in vitro perspectives

Phenolics, abundant in plants, constitute a significant portion of phytoconstituents consumed in the human diet. The phytochemical screening of the aerial parts of Centaurium spicatum led to the isolation of five phenolics. The anti-tyrosinase activities of the isolated compounds were assessed through a combination of in vitro experiments and multiple in silico approaches. Docking and molecular dynamics (MD) simulation techniques were utilized to figure out the binding interactions of the isolated phytochemicals with tyrosinase. The findings from molecular docking analysis revealed that the isolated phenolics were able to bind effectively to tyrosinase and potentially inhibit substrate binding, consequently diminishing the catalytic activity of tyrosinase. Among isolated compounds, cichoric acid displayed the lowest binding energy and the highest extent of polar interactions with the target enzyme. Analysis of MD simulation trajectories indicated that equilibrium was reached within 30 ns for all complexes of tyrosinase with the isolated phenolics. Among the five ligands studied, cichoric acid exhibited the lowest interaction energies, rendering its complex with tyrosinase the most stable. Considering these collective findings, cichoric acid emerges as a promising candidate for the design and development of a potential tyrosinase inhibitor. Furthermore, the in vitro anti-tyrosinase activity assay unveiled significant variations among the isolated compounds. Notably, cichoric acid exhibited the most potent inhibitory effect, as evidenced by the lowest IC50 value (7.92 ± 1.32 µg/ml), followed by isorhamnetin and gentiopicrin. In contrast, sinapic acid demonstrated the least inhibitory activity against tyrosinase, with the highest IC50 value. Moreover, cichoric acid exhibited a mixed inhibition mode against the hydrolysis of l-DOPA catalyzed by tyrosinase, with Ki value of 1.64. Remarkably, these experimental findings align well with the outcomes of docking and MD simulations, underscoring the consistency and reliability of our computational predictions with the actual inhibitory potential observed in vitro.

A Characterization of Biological Activities and Bioactive Phenolics from the Non-Volatile Fraction of the Edible and Medicinal Halophyte Sea Fennel (Crithmum maritimum L.).

Although the biochemical composition and biological properties of the volatile fraction of the halophyte sea fennel (Crithmum maritimum L.) have been largely described, little is known about its polar constituents and bioactivities. Here, a hydromethanolic extract of Crithmum maritimum (L.) leaves was fractionated, and the fractions were evaluated in vitro for antioxidant (using DPPH, ABTS, and FRAP bioassays), anti-inflammatory (inhibition of NO production in RAW 264.7 macrophages), antidiabetic (alpha-glucosidase inhibition), neuroprotective (inhibition of acetylcholinesterase), and skin-protective (tyrosinase and melanogenesis inhibitions) activities. Polar fractions of the extract were rich in phenolics and, correlatively, displayed a strong antioxidant power. Moreover, fractions eluted with MeOH20 and MeOH80 exhibited a marked inhibition of alpha-glucosidase (IC50 = 0.02 and 0.04 mg/mL, respectively), MeOH60 fractions showed a strong capacity to reduce NO production in macrophages (IC50 = 6.4 μg/mL), and MeOH80 and MeOH100 fractions had strong anti-tyrosinase activities (630 mgKAE/gDW). NMR analyses revealed the predominance of chlorogenic acid in MeOH20 fractions, 3,5-dicaffeoylquinic acid in MeOH40 fractions, and 3-O-rutinoside, 3-O-glucoside, 3-O-galactoside, and 3-O-robinobioside derivatives of quercetin in MeOH60 fractions. These compounds likely account for the strong antidiabetic, antioxidant, and anti-inflammatory properties of sea-fennel polar extract, respectively. Overall, our results make sea fennel a valuable source of medicinal or nutraceutical agents to prevent diabetes, inflammation processes, and oxidative damage.

Tyrosinase and Peroxiredoxin Inhibitory Action of Ethanolic Extracts of Memecylon malabaricum Leaves

The study aimed to determine the tyrosinase and peroxiredoxin inhibitory action of ethanolic extracts of Memecylon malabaricum leaves. The phytoconstituents present in Memecylon malabaricum were analysed for their inhibitory activity against the tyrosinase and peroxiredoxin enzymes by molecular docking, and their molecular interactions were confirmed. The Qikprop module checked their pharmacokinetic profiles. The ethanolic extracts were prepared, and they were analysed for antityrosinase and antioxidant activity by in vitro methods. All the fourteen phytoconstituents obtained from Memecylon malabaricum were docked with two proteins, tyrosinase (5I38) and peroxiredoxin (1HD2), and MM1 was the well-interacted compound. The ethanolic extract was evaluated for tyrosinase inhibitory activity and antioxidant activity using the DPPH radical scavenging method and was compared with the standard ascorbic acid. It was concluded that the ethanolic extract of Memecylon malabaricum was active, and further pharmacological studies were needed to confirm their potency.

Evaluation of the in vitro enzyme inhibition and antioxidant activity of Clinopodium betulifolium (Boiss. & Balansa) Kuntze

Clinopodium betulifolium (Boiss. & Balansa) Kuntze is a perennial herb belonging to the Lamiaceae family. There are few studies on C. betulifolium, except for its essential oil. In this study, Alzheimer's and cosmetic-related enzyme inhibitory activity and antioxidant activity of C. betulifolium species were evaluated. This study extracted C. betulifolium aerial parts by maceration using 70% methanol and water. Antioxidant [DPPH scavenging assay, ABTS cation decolorization, and iron chelating activity] and enzyme inhibition (acetyl-, and butyrylcholine esterase, and tyrosinase) activities of C. betulifolium extracts were evaluated using Elisa microplate reader at 2 mg mL-1 stock concentration. C. betulifolium aqueous extract gave high antioxidant activity (IC50: 34.24 ± 5.01 µg mL-1) in the ABTS method, while its 70% methanol extract (IC50: 100.75 ± 2.62 µg mL-1) was higher than the aqueous extract (IC50: 131.83 ± 4.70 µg mL-1) in the DPPH method. C. betulifolium aqueous and 70% methanol extract have moderate anti-tyrosinase activity. Both 70% methanol and aqueous extracts showed similar and high activity against acetylcholinesterase with the IC50 values of 73.94 ± 2.78 µg mL-1 and 81.71 ± 9.38 µg mL-1, respectively. C. betulifolium 70% methanol extract (IC50: 64.08 ± 1.04 µg mL-1) showed higher inhibitory activity than the aqueous extract (IC50: 146.6 ± 8.27 µg mL-1) against butyrylcholinesterase. These results provide basic information for studies that will yield positive results in the development of pharmaceutical formulations or food supplements to be used to treat Alzheimer's and oxidative stress-related diseases.

Synergistic Biomedical Potential and Molecular Docking Analyses of Coumarin-Triazole Hybrids as Tyrosinase Inhibitors: Design, Synthesis, In Vitro Profiling, and In Silico Studies.

The tyrosinase enzyme has a vital role in the browning of vegetables and fruits and the biosynthesis of melanin. In this work, we synthesized a diverse library of coumarin-triazole hybrids, and these compounds were characterized by using suitable analytical techniques. Our research work extends beyond the synthetic effort to explore the therapeutic potential of these compounds. We put the synthesized compounds through meticulous in vitro screening against the tyrosinase enzyme, and these coumarin derivatives evinced good IC50 values in the range of 0.339 ± 0.25 µM to 14.06 ± 0.92 µM. In the library of synthesized compounds, six compounds were found to be more potent than standard ascorbic acid (IC50 = 11.5 ± 1.00), and among them, 17e and 17f, being the most active, exhibited remarkable anti-tyrosinase potential, with IC50 values of 0.339 ± 0.25 μM and 3.148 ± 0.23 μM, respectively. Furthermore, an in silico modeling study was carried out to determine the key interactions of these compounds with the tyrosinase protein (PDB ID: 2Y9X) and thus to authenticate our experimental findings. The quantitative SAR studies exhibited a good correlation between the synthesized derivatives of coumarin and their anti-tyrosinase activity. The docking studies verified the experimental results, and ligand 17e showed good interaction with the core residues of tyrosinase. This study not only expands the field of coumarin-triazole hybrid synthesis but also provides valuable insights for the development of novel tyrosinase inhibitors.

The innovative extraction and purification process of insoluble polyphenols from Paeonia ostii roots: Optimum study and in vitro activities

The oil tree peony (Paeonia ostii) is widely cultivated for their high value seed oil, and its roots also have high medicinal value, but they are often discarded and wasted as by-products. In this study, a set of steam explosion (SE) and ultrasound (US)-assisted extraction/purification methods of insoluble bound phenols (IPs) from oil peony roots (PR) were explored and developed. The IPs were obtained through SE pre-treatment (120 °C, 15 min) and US-assisted alkaline extraction (0.25 W/cm2, 4 h and 4 M NaOH). Their total phenolic content (TPC) significantly increased from 112.26 mg gallic acid/g dry weight (mg GAE/g dw) with traditional method to 185.59 mg GAE/g dw. Subsequently, the IPs were purified into PIPs using LX-83 resin. The optimized purification conditions were pH = 4, 3.0 mg GAE/mL of IPs, 0.25 W/cm2 adsorption for 120 min, as well as 60 % ethanol desorption solution, and 0.25 W/cm2 desorption for 30 min. The TPC of the PIPs increased to 254.74 mg GAE/g dw. Notably, typical compounds in IPs and PIPs were identified and quantified by HPLC-MS and their antioxidant and anti-tyrosinase activities were also evaluated by chronometry. The results showed that paeoniflorin and benzoyl-paeoniflorin increased by about 10-fold in the PIPs. Additionally, they demonstrated superior antioxidant and tyrosinase inhibitory activities compared to IPs. Therefore, the innovative extraction and purification process greatly improved the yield of bound phenols and recovered paeoniflorin from non-medicinal PR. The process may also provide a reference for the in-depth development of medicinal PR, ultimately achieving more efficient PR development and utilization.