Antityrosinase activity of Euphorbia characias extracts

Skin-whitening effects of Spergularia marina by suppressing MITF translocation

Spergularia marina is a plant that grows in salty regions along the coastline and exerts radical-scavenging and anti-inflammatory effects. In this study, we investigated the skin-whitening effects of S. marina extract (SME) in B16F10 melanoma cells. SME was found to exert radical-scavenging effects. It suppressed α-melanocyte-stimulating hormone-induced melanogenesis and tyrosinase activity. We also assessed the melanin production signaling pathway to identify the inhibitory action mechanism of SME on melanogenesis. SME decreased the protein expression levels of tyrosinase-related protein (TRP)-1, TRP-2, and tyrosinase, which play important roles in melanogenesis. Furthermore, western blotting revealed that SME inhibited the nuclear translocation of melanocyte inducing transcription factor (MITF), which is a transcription factor for TRP-1, TRP-2, and tyrosinase, suggesting that SME exerts its skin-whitening effect by inhibiting MITF nuclear translocation. Therefore, SME may potentially be used in skin-whitening medicines and cosmetics.

Antioxidant activity, anti-tyrosinase activity, molecular docking studies, and molecular dynamic simulation of active compounds found in nipa palm vinegar

Tyrosinase is a key enzyme in melanogenesis and its inhibitors have become increasingly because of their potential activity as hypopigmenting agents which have less side effects. Nipa palm vinegar is an aqueous product that is normally used as a food supplement. The aim of this study was to study the determination of antioxidant activity and tyrosinase inhibitory activities of aqueous extract of original nipa palm vinegar (AE O-NPV), nipa palm vinegar powder (NPV-P) and aqueous extract of nipa palm vinegar powder (AE NPV-P) were examined. Nipa palm vinegars were evaluated the phenolic and flavonoid content, and the active compounds which were submitted to molecular docking and molecular dynamic simulation, chemoinformatics, rule of five, skin absorption and toxicity. The highest phenolic and flavonoid contents in the AE O-NPV were 2.36 ± 0.23 mg gallic acid equivalents/g extract and 5.11 ± 0.59 mg quercetin equivalents/g, and the highest ABTS radical cation scavenging activity was also found. The AE O-NPV, NPV-P and AE NPV-P showed anti-mushroom tyrosinase activity. The HPLC analysis showed that there were vanillic acid and three flavonoids (catechin, rutin and quercetin). The molecular docking study revealed that the binding of the vanillic acid and three flavonoids occurred in the active site residues (histidine and other amino acids). Moreover, the number of hydrogen bond acceptors/donors, solubility, polar surface area and bioavailability score of the vanillic acid and three flavonoids were acceptable compared to Lipinski's Rule of Five. The molecular dynamic simulation showed that vanillic acid interacts with HIS284 through π-π stacking hydrophobic interactions and forms a metal-acceptor interaction with the copper molecule at the tyrosinase active site. All compounds revealed good skin permeability and nontoxicity. Nipa palm vinegar could be a promising source of a new ingredient for tyrosinase inhibition for cosmetics or pharmaceutical products.

Pharmacognostical and Phytochemical Studies and Biological Activity of Curculigo latifolia Plant Organs for Natural Skin-Whitening Compound Candidate

Curculigo latifolia (family Amaryllidaceae) is used empirically for medicinal purposes. It is distributed throughout Asian countries, especially Indonesia. This study aimed at standardizing the C. latifolia plant, analyzing its phytochemical profile, and evaluating its pharmacological effects. The powder from each organ (root, stem, and leaves) was standardized organoleptically and microscopically. Samples were extracted by graded maceration using hexane, ethyl acetate, and ethanol. The extracts were determined for total phenolic content (TPC) and total flavonoid content (TFC). Antioxidant (radical scavenging and metal ion reduction) and antityrosinase activities were determined by spectrophotometric methods. Extracts were analysed for phytochemical profiles by LC-ESI-MS. The highest TPC and TFC were found in the ethanolic extract of the root organ (68.63 ± 2.97 mg GAE/g) and the ethyl acetate extract of the stem (14.33 ± 0.71 mg QE/g extract). High antioxidant activities were found in the ethanolic root extract (20.42 ± 0.33 µg/mL) and ethanolic stem extract (45.65 ± 0.77 µg/mL) by DPPH• and NO• assays, respectively. The ion reduction activity (by CUPRAC assay) was most significant in the ethyl acetate stem extract (390.42 ± 14.49 µmol GAEAC/g extract). Ethanolic root extract was the most active in inhibiting tyrosinase (IC50 value of 108.5 µg/mL). The correlation matrix between TPC and antioxidant activities showed a moderate to robust correlation, whereas the TPC and antityrosinase activity showed a robust correlation. The TFC and antioxidant or antityrosinase activities showed a weak to moderate correlation. The LC-ESI-MS data identified major phenols in the active extracts, including methyl 3-hydroxy-4-methoxy-benzoate, quercetin, 4-O-caffeoylquinic acid-1, and curculigoside. Overall, this study suggests that extracts from the C. latifolia plant offer potent antioxidant and antityrosinase activities, allowing them to be used as natural antioxidants and candidates for skin-lightening compounds.

Screening and Structure-Activity Relationship for Selective and Potent Anti-Melanogenesis Agents Derived from Species of Mulberry (Genus Morus)

Tyrosinase is a multifunctional, copper-containing and rate-limiting oxidase that catalyses crucial steps in the melanogenesis pathway and is responsible for skin-pigmentation abnormalities in mammals. Numerous tyrosinase inhibitors derived from natural and synthetic sources have been identified as an objective for the development of anti-melanogenesis agents. However, due to side effects and lack of expected efficiency, only a small percentage of them are used for medical and cosmetic purposes. This critical review focuses on searching for novel active substances and recently discovered plant-derived anti-tyrosinase inhibitors from the Morus genus (Moraceae family). A detailed analysis of their structure-activity relationships is discussed. The information contained in this article is crucial for the cosmetics and medical industries, in order to show new directions for the effective search for natural anti-melanogenesis products (with satisfactory efficiency and safety) to treat and cure hyperpigmentation.

In vitro acetylcholinesterase, tyrosinase inhibitory potentials of secondary metabolites from Euphorbia schimperiana and Euphorbia balsamifera

Acetylcholinesterase, tyrosinase, and α-glucosidase inhibition activities of Euphorbia schimperiana and Euphorbia balsamifera extracts, fractions, and available pure compounds were evaluated for the first time. Acetylcholinesterase assay revealed a significant inhibitory activity of E. balsamifera total extract and n-hexane fraction with 47.7% and 43.3%, respectively, compared to the reference drug, which was 75%. The n-butanol fraction demonstrated tyrosinase inhibitory activity for E. balsamifera and E. schimperiana with 36.7% and 29.7%, respectively, compared to 60% for the reference drug. Quercetin-3-O-α-glucuronide, quercetin-3-O-β-D-glucuronide-methyl ester, quercetin-3-O-α-L-rhamnoside, 3,3′-di-O-methyl ellagic acid, 3,3′-di-O-methyl-ellagic acid-4-β-D-xylopyranoside, and 4-O-ethyl gallic acid were identified from E. schimperiana while quercetin-3-O-glucopyranoside and isoorientin were determined from E. balsamifera. The AChE inhibitory effect of pure compounds exhibited promising activity, where 4-O-ethylgallic acid demonstrated 51.1%, while the highest tyrosinase inhibition was demonstrated by isoorientin with 50.6% compared to the reference drug (60%). Finally, a molecular docking study was performed for the most promising AChE and tyrosinase inhibitors. The extracts, fractions, and isolated compounds showed no α-glucosidase inhibitory activity.

Euphorbia characias Extract: Inhibition of Skin Aging-Related Enzymes and Nanoformulation

Plant extracts have long served as important sources of bioactive compounds, and they are currently the focus of extensive research in the development of novel preventive and therapeutic strategies. However, their health benefits are often limited by low bioavailability. Nanoparticle delivery systems can represent a solution to such limitations. Euphorbia characias is a Mediterranean shrub known to have biological activities, such as inhibiting tyrosinase and showing a potential role as a skin-whitening agent. In this study, an ethanolic extract from E. characias leaves was tested for its inhibitory activity on skin-related enzymes, such as elastase, collagenase, and hyaluronidase, and for sun protection factors. Moreover, the extract was formulated in phospholipid vesicles to improve its local bioavailability and applicability. The vesicles were characterized by size, surface charge, storage stability, and entrapment efficiency. The nanoformulation was also evaluated for antioxidant activity and assayed for cytocompatibility and anti-tyrosinase activity in melanoma cells. Our findings demonstrated that the extract has a photo-protective effect and enzyme-inhibitory properties. E. characias nanoformulation was also cytocompatible and improved the extract’s activity in the cells, suggesting a potential skin application for antimelanogenic treatments and confirming the key role of nanotechnological approaches to maximize plant extract’s potentialities.

In vitro studies on the cytotoxicity, elastase, and tyrosinase inhibitory activities of tomato (Solanum lycopersicum Mill.) extract

Tomatoes (Solanum lycopersicum Mill.), a common vegetable in Indonesia, contain high levels of lycopene, which is good for the body. This research further investigates the activity of polar and nonpolar fractions of tomatoes as elastase and tyrosinase inhibitory, and cytotoxic agents. The extraction procedure used is maceration, fractionation through liquid-liquid fractionation, purification of phytochemical substances is achieved through the application of thin layer chromatography. Elastase and tyrosinase inhibitory activity was analyzed using spectrophotometry and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxic assay. The result showed that the extract yield was 0.004%. The percentage of polar fraction from the extract was 2.58%, while the nonpolar fraction was 0.69%. The elastase inhibitory activity of polar and nonpolar fractions of tomato extract is 87.21% ± 7.57% and 73.12% ± 7.44%, respectively, The elastase inhibitory activity of polar and nonpolar fractions of tomato extract is 87.21% ± 7.57% and 73.12% ± 7.44%, respectively. The fractions had higher the anti-elastase activity than the positive control quercetin (65.97% ± 3.00%). The tyrosinase inhibitory activity of polar and nonpolar fractions of tomato extract is 23.71% ± 7.91% and 41.16% ± 5.41% (kojic acid as standard is 65.07% ± 0.86%), respectively. The IC₅₀ of the cytotoxic assay to NIH 3T3 mouse embryonic fibroblast cells of the polar and nonpolar fraction of tomato extract is 1820.90 μg/mL and 1643.86 μg/mL, respectively.

Three New Isoprenylated Flavones from Artocarpus chama Stem and Their Bioactivities

Phytochemical investigation of Artocarpus chama stem was performed by chromatographic techniques, resulting from the isolation and structure elucidation of three new compounds, namely 3′-farnesyl-apigenin (1), 3-(hydroxyprenyl) isoetin (2), and 3-prenyl-5,7,2′,5′-tetrahydroxy-4′-methoxyflavone (3), and five known compounds, namely homoeriodictyol (4), isocycloartobilo-xanthone (5), artocarpanone (6), naringenin (7), and artocarpin (8). From the screening result, A. chama extract showed a potent tyrosinase inhibitory effect. Ihe isolated compounds 1, 4 and 6 also exhibited tyrosinase inhibition with IC50 of 135.70, 52.18, and 38.78 µg/mL, respectively. Moreover, compounds 3, 4, 5, 6, and 8 showed strong activity against Staphylococcus epidermidis, S. aureus, methicillin-resistant S. aureus, and Cutibacterium acnes. This study is the first report on phytochemical investigation with new compounds and biological activities of A. chama. Skin infection can cause dark spots or hyperpigmentation. The isolated compounds that showed both anityrosinase and antimicrobial activities will be further studied in in vivo and clinical trials in order to develop treatment for hyperpigmentation, which is caused by infectious diseases by microorganisms.

Euphorbia characias: Phytochemistry and Biological Activities

The aim of this review is to summarize all the compounds identified and characterized from Euphorbia characias, along with the biological activities reported for this plant. Euphorbia is one of the greatest genera in the spurge family of Euphorbiaceae and includes different kinds of plants characterized by the presence of milky latex. Among them, the species Euphorbia characias L. is an evergreen perennial shrub widely distributed in Mediterranean countries. E. characias latex and extracts from different parts of the plant have been extensively studied, leading to the identification of several chemical components such as terpenoids, sterol hydrocarbons, saturated and unsaturated fatty acids, cerebrosides and phenolic and carboxylic acids. The biological properties range between antioxidant activities, antimicrobial, antiviral and pesticidal activities, wound-healing properties, anti-aging and hypoglycemic properties and inhibitory activities toward target enzymes related to different diseases, such as cholinesterases and xanthine oxidase. The information available in this review allows us to consider the plant E. characias as a potential source of compounds for biomedical research.

Selecting and Characterizing Tyrosinase Inhibitors from Atractylodis macrocephalae Rhizoma Based on Spectrum-Activity Relationship and Molecular Docking

Atractylodis macrocephalae Rhizoma (AMR) is a famous classical Chinese traditional medicine (CTM), which has been used as a tonic for many diseases for thousands of years. In ancient China, it was used as a supplementary food for beauty in the palace. In preliminary studies, the function of whitening skin and the significant inhibiting effect on tyrosinase (TYR) which is the reactive enzyme in the composition of melanin of AMR were discovered, and the relevant research was rarely reported. In this study, high-performance liquid chromatography (HPLC) along with partial least squares regression analysis (PLS) was applied to survey the coherence between the chemical constituents and the inhibiting activity of 11 batches of AMR on TYR activity. The results of PLS showed that the chromatographic peaks 11 (atractylenolide III) and 15 could be important effective ingredients of the inhibition TYR activity as ascertained by spectrum-activity relationships. Furthermore, TYR inhibitory activity of atractylenolide III was validated by in vitro test by β-arbutin served as a positive control drug. The results of the in vitro test and the molecular docking showed that atractylenolide III has high TYR inhibitory activity and could link to the residues in TYR catalytic pocket. Therefore, bioassay, molecular docking, and spectrum-activity relationships are appropriate for linking the quality of samples with pharmaceutical-related active ingredients. And our studying would lay a theoretical foundation for applying the water extracts of AMR in whitening cosmetics.

Anti-Aging Potential of Extracts from Washingtonia filifera Seeds

The aim of this study was to test the inhibitory effect of fruit extracts from Washingtonia filifera on skin aging-related enzymes. The pulp extracts did not exert a significant enzyme inhibition while seed extracts from W. filifera exhibit anti-elastase, anti-collagenase, and anti-tyrosinase activities. Tyrosinase was mildly inhibited while a stronger effect was observed with respect to elastase and collagenase inhibition. Alcoholic extracts provided better results than aqueous extracts. Among them, methanol extracts showed the prominent enzyme inhibitory activities being IC50 value for elastase and collagenase comparable and even better than the reference compound. The inhibition mode of the most active extracts was investigated by Lineweaver-Burk plot analysis. Seed extracts from W. filifera were also investigated for their photo-protective effect by Mansur equation and the antioxidant activity of W. filifera extract was evaluated in oxidative-stressed cells. To evaluate the safety of the extract, the effect on cell viability of human keratinocytes cells was analyzed. Methanol extract presented the best photo-protective effect and exerted an antioxidant activity in a cellular system with no cytotoxic effect. The overall results demonstrate that W. filifera extracts are promising sources of bioactive compounds that could be used in cosmetic and pharmaceutical preparation.

Structure of a nucleotide pyrophosphatase/phosphodiesterase (NPP) from Euphorbia characias latex characterized by small-angle X-ray scattering: clues for the general organization of plant NPPs

Little information is available concerning the structural features of nucleotide pyrophosphatase/phosphodiesterases (NPPs) of plant origin and the crystal structures of these proteins have not yet been reported. The aim of this study was to obtain insight into these aspects by carrying out a comparative analysis of the sequences of two different fragments of an NPP from the latex of the Mediterranean shrub Euphorbia characias (ELNPP) and by studying the low-resolution structure of the purified protein in solution by means of small-angle X-ray scattering. This is the first structure of a plant NPP in solution that has been reported to date. It is shown that the ELNPP sequence is highly conserved in many other plant species. Of note, the catalytic domains of these plant NPPs have the same highly conserved PDE-domain organization as mammalian NPPs. Moreover, ELNPP is a dimer in solution and this oligomerization state is likely to be common to other plant enzymes.

Antityrosinase Activity of Combretum micranthum, Euphorbia hirta and Anacardium occidentale Plants: Ultrasound Assisted Extraction Optimization and Profiling of Associated Predominant Metabolites

Tyrosinase is an important component of the enzyme polyphenol oxidase, which upon contact with the phenolic substrates forms the pigment melanin and induces undesirable food browning. The phenolic and triterpenoid compounds that naturally occur in plants are well known as tyrosinase inhibitors. Combretum micranthum (CM) leaves, Euphorbia hirta (EH) plant, and Anacardium occidentale (AO) fruits are traditionally known to have potential anti-tyrosinase activities. The aim of this study was to optimize the ultrasound-assisted extraction of secondary metabolites from these matrices, and to evaluate in tubo the antityrosinase activity of these extracts. Efforts were also taken to profile the secondary metabolites, mainly the phenolic and triterpenoid compounds, in order to understand their probable association with tyrosinase inhibition. The optimal ultrasound-assisted extraction conditions for simultaneous extraction of phenolic, and triterpenoid compounds were determined. The aqueous fraction of these extracts showed significant antityrosinase activity, with the CM leaves exhibiting the strongest inhibitory effect (IC50 of 0.58 g·L-1). The predominant metabolic compounds from these natural extracts were putatively identified by using a high-resolution quadrupole-time of flight (QToF) LC-MS instrument. The high-resolution accurate mass-based screening resulted in identification of 88 predominant metabolites, which included dihydrodaidzein-7-O-glucuronide, micromeric acid, syringic acid, morin, quercetin-3-O-(6″-malonyl-glucoside), 4-hydroxycoumarin, dihydrocaffeic acid-3-O-glucuronide, to name some, with less than 5 ppm of mass error.

Inhibitory Effect of Sesamolin on Melanogenesis in B16F10 Cells Determined by In Vitro and Molecular Docking Analyses

BACKGROUND

Melanin protects the skin against the harmful effects of ultraviolet irradiation. However, melanin overproduction can result in several aesthetic problems, including melasma, freckles, age spots and chloasma. Therefore, development of anti-melanogenic agents is important for the prevention of serious hyperpigmentation diseases. Sesamolin is a lignan compound isolated from sesame seeds with several beneficial properties, including potential for melanin inhibition.

OBJECTIVE

The aim of this study was to evaluate the anti-melanogenic effect of sesamolin in cell culture in vitro and the underlying mechanism of inhibition using molecular docking simulation.

METHODS

Melanogenesis was induced by 3-isobutyl-1-methylxanthine in B16F10 melanoma cells, and the inhibitory effects of sesamolin were evaluated using zymography, a tyrosinase inhibitory activity assay, western blotting, and real-time reverse transcription-polymerase chain reaction analysis. Docking simulations between sesamolin and tyrosinase were performed using Autodock vina.

RESULTS

Sesamolin significantly inhibited the expression of melanogenesis-related factors tyrosinase, and tyrosinase-related proteins 1 and 2 at the mRNA and protein levels. Treatment of melanoma cells with 50 µM sesamolin demonstrated the strongest inhibition against intercellular tyrosinase and melanin synthesis without exerting cytotoxic effects. Sesamolin significantly reduced mushroom tyrosinase activity in a dose-dependent manner via a competitive inhibition mechanism. Tyrosinase docking simulations supported that sesamolin (-6.5 kcal/mol) bound to the active site of tyrosinase more strongly than the positive control (arbutin, -5.7 kcal/mol).

CONCLUSION

Sesamolin could be developed as a melanogenesis inhibiting agent owing to its dual function in blocking the generation of melanogenesis-related enzymes and inhibiting the enzymatic response of tyrosinase.

Optimization of Ultrasonic Flavonoid Extraction from Saussurea involucrate, and the Ability of Flavonoids to Block Melanin Deposition in Human Melanocytes

(1) Background: Flavonoids are the primary medicinal ingredient of Saussurea involucrate, which have significant antioxidant capacity. Optimizing the extraction of Saussurea involucrate flavonoids (SIFs) and exploring the ability to block melanin deposition caused by reactive oxygen can greatly promote the development of S. involucrate whitening products. (2) Methods: Ultrasonic extraction process was optimized using the Box-Behnken design (BBD) and response surface methodology (RSM). Then, the effect of SIFs on antioxidant activity and anti-deposition of melanin, and genes related to the melanin synthesis are studied. (3) Results: The optimal extraction procedures are as follows: the extraction time, ethanol content, and solvent ratio (v/w) are 64 min, 54%, and 54:1, respectively. The reducing activity and scavenging rates of 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, hydroxyl radical, and ABTS⁺ were promoted as more S. involucrate flavonoid extract was added. The SIFs extract induced a decrease in the melanin synthesis by inhibiting the human melanoma A375 cell tyrosinase activity. SIFs also depress expression of melanin synthesis related genes. (4) Conclusions: the highest SIFs content was obtained by using 54% ethanol and 54:1 solvent ratio (v/w) for 64 min. The extract of SIFs exhibited good ability of antioxidant and anti-deposition of melanin in human melanocytes.

Efficiency of Skin Whitening Cream Containing Etlingera elatior Flower and Leaf Extracts in Volunteers

Our previous research demonstrated that Etlingera elatior possesses whitening and anti-aging properties and also contains bioactive ingredients for cosmeceuticals. Therefore, this research work aimed to evaluate the efficiency of whitening cream containing both the flower and leaf extracts of E. elatior in human volunteers and their degree of skin irritation. Both the flower and leaf extracts were formulated as a cosmetic called “FL1 cream”, which was assessed for its physical properties and underwent an accelerated stability test. The FL1 cream was also evaluated for skin irritation and its skin whitening effect among 24 healthy volunteers who used it for four weeks. The FL1 cream demonstrated good physical stability under the various conditions for three months, along with six cycles of heating/cooling. The irritation analysis showed that irritation reactions were absent in all volunteers. The efficiency of FL1 cream in improving the appearance of skin whitening was demonstrated by a significant (p < 0.05) and continuous decrease in melanin content compared with the initial value. Additionally, the L* value was significantly and continuously increased after application of the FL1 cream. The highest melanin reduction was 6.67%. The FL1 cream containing E. elatior extracts can be used as a whitening cream in cosmetics.

Isocostic Acid, a Promising Bioactive Agent from the Essential Oil of Inula viscosa (L.): Insights from Drug Likeness Properties, Molecular Docking and SAR Analysis

The chemical composition of the essential oil (LEO) and its volatile fractions (V₁ -V₁₀ ) collected during the hydrodistillation process every 15 min from the fresh leaves of I. viscosa (L.), growing in Tunisia, were analyzed by GC-FID and GC/MS. Eighty-two compounds, representing 90.9-99.4 % of the total samples, were identified. The crude essential oil (LEO) and its fractions (V₁ -V₁₀ ) were characterized by the presence of a high amount of oxygenated sesquiterpenes (82.7-95.8 %). Isocostic acid (1) was found to be the most abundant component (37.4-83.9 %) and was isolated from the same essential oil over silica gel column chromatography and identified by spectroscopic methods (¹ H, ¹³ C, DEPT 135 NMR and EI-MS) and by comparison with literature data. Furthermore, the fresh leaves essential oil (LEO), its volatile fractions (V₁ -V₁₀ ) as well as compound 1 were screened for their antibacterial, antityrosinase, anticholinesterase and anti-5-lipoxygenase activities. It was found that the isolated compound 1 exhibited an interesting antibacterial activity against Staphylococcus aureus ATCC 25923 (MIC=32 μg/mL) and Enterococcus faecalis ATCC 29212 (MIC=32 μg/mL) and the highest antityrosinase activity (IC₅₀ =13.82±0.87 μg/mL). Compound 1 was also found to be able to strongly inhibit 5-lipoxygenase with an IC₅₀ value of 59.21±0.85 μg/mL. The bioactivity and drug likeness scores of compound 1 were calculated using Molinspiration software and interpreted, and the structure-activity relationship (SAR) was discussed with the help of molecular docking analysis.

Preparation and characterization of sericin powder extracted with deep sea water

In this study, we developed an effective technology for the extraction of sericin from silk cocoons by deep sea water (DSW). We focused on extraction of sericin in the absence of chemical additives to obtain a safe, effective, inexpensive sericin powder. Sericin was extracted using a simple high-temperature process involving heating, condensation with Molus alba, filtering with cotton cloth, cold storage, and lyophilization. The results showed that the yield of sericin (26%) extracted by DSW was approximately 2% higher than that obtained using a chemical buffer (0.2 M Na₂CO₃, 24%). The marine mineral sericin M. alba (MSM) showed a size distribution of 15-250 kDa, with major peaks at 75-250 kDa with a galactose chain. Additionally, this MSM product had high antioxidant, whitening, and antibiosis effects and could be safely stored for a long time. Thus, our findings supported the use of a DSW extraction method, which was ecofriendly and yielded a proteinous, biodegradable biopolymer, for preparation of sericin.

Comparing enzyme activity modifier equations through the development of global data fitting templates in Excel

The classical way of defining enzyme inhibition has obscured the distinction between inhibitory effect and the inhibitor binding constant. This article examines the relationship between the simple binding curve used to define biomolecular interactions and the standard inhibitory term (1 + ([I]∕K_i)). By understanding how this term relates to binding curves which are ubiquitously used to describe biological processes, a modifier equation which distinguishes between inhibitor binding and the inhibitory effect, is examined. This modifier equation which can describe both activation and inhibition is compared to standard inhibitory equations with the development of global data fitting templates in Excel and via the global fitting of these equations to simulated and previously published datasets. In both cases, this modifier equation was able to match or outperform the other equations by providing superior fits to the datasets. The ability of this single equation to outperform the other equations suggests an over-complication of the field. This equation and the template developed in this article should prove to be useful tools in the study of enzyme inhibition and activation.

The development of a Panax notoginseng medicinal liquor processing technology using the response surface method and a study of its antioxidant activity and its effects on mouse melanoma B16 cells

Panax notoginseng medicinal liquor (PML) has a long history of use in the function of blood circulation. However, the processing of PML is currently dependent on experience, which results in low efficiency and unstable quality of PML. A variety of substances of P. notoginseng have a strong ability to scavenge free radicals and antioxidant activity, but the antioxidant activity of PML has not been formally researched. The aim of the present study was to optimize the processing technology of PML and to verify the anti-oxidation and anti-deposition of melanin functions of PML. Based on the Box-Behnken design of response surface method, the PML processing parameters were established as follows: the ratio of liquid to solid 32 : 1, 53% of alcohol, and soaking time of 35 d. With elevating concentration of PML extract, the reducing force and scavenging rates of DPPH, superoxide anion, hydroxyl radical and ABTS⁺ were increased, and the inhibition rate of tyrosinase activity and the melanin synthesis ability were increased in mice melanoma B16 cells. Thus, the optimal processing technology not only shortened the processing time but also decreased the material costs. PML may be developed as food or beauty products for the functions of anti-oxidation and anti-deposition of melanin.

Selected Enzyme Inhibitory Effects of Euphorbia characias Extracts

Extracts of aerial part of Euphorbia characias were examined to check potential inhibitors for three selected enzymes involved in several metabolic disorders. Water and ethanol extracts from leaves and flowers showed in vitro inhibitory activity toward α-amylase, α-glucosidase, and xanthine oxidase. IC₅₀ values were calculated for all the extracts and the ethanolic extracts were found to exert the best effect. In particular, for the α-glucosidase activity, the extracts resulted to be 100-fold more active than the standard inhibitor. The inhibition mode was investigated by Lineweaver-Burk plot analysis. E. characias extracts display different inhibition behaviors toward the three enzymes acting as uncompetitive, noncompetitive, and mixed-type inhibitors. Moreover, ethanolic extracts of E. characias showed no cytotoxic activity and exhibited antioxidant capacity in a cellular model. The LC-DAD metabolic profile was also performed and it showed that leaves and flowers extracts contain high levels of quercetin derivatives. The results suggest that E. characias could be a promising source of natural inhibitors of the enzymes involved in carbohydrate uptake disorders and oxidative stress.

A review of the traditional and modern uses of Salvadora persica L. (Miswak): Toothbrush tree of Prophet Muhammad

ETHNOPHARMACOLOGICAL RELEVANCE

Salvadora persica L., also known as Arak (in Arabic) and Peelu (in Urdu), is the most common traditional source of tooth or chewing stick (miswak) highly recommended by Prophet Muhammad. To date, extensive studies have probed primarily into the validation of its traditional uses in oral care. Nonetheless, there is still a dearth of updated compilation and critical analysis of other potential ethnopharmacological properties of S. persica. This review therefore aims to provide an up-to-date detailed structured description of the traditional uses of S. persica and a critical analysis of its modern uses, highlighting its phytochemistry, pharmacological properties, and bioapplications.

MATERIALS AND METHODS

Various databases (Science Direct, PubMed, Wiley Online Library, and Google Scholar), books, and relevant primary sources were probed, surveyed, analysed, and included in this review. The literature cited in this review dated from 1979 to 2017.

RESULTS

S. persica was found to possess a plethora of bioactive compounds and broad pharmacological properties, including antimicrobial, antioxidant, enzyme inhibitory activity, antiulcer, anticonvulsant, sedative, analgesic, anti-inflammatory, hypoglycemic, hypolipidemic, antiosteoporosis, and antitumor activities. Studies also revealed the potential use of S. persica as a natural food preservative and a novel functional food ingredient. In addition, improvement in growth and reproductive performances have been observed by the introduction of S. persica in animal feed. Lastly, S. persica has also been used in the green synthesis of nanoparticles showing potential biotechnological applications.

CONCLUSION

S. persica showed a wide scope of application and its uses have been extended far beyond the initial traditional uses of its roots, stems, and twigs in oral care. We found a number of other ethnopharmacological uses and potential bioapplications of different parts of S. persica that warrants further investigations. Though widely studied using several in vitro and in vivo models, and tested clinically for oral hygiene mainly, several gaps and research priorities have been identified which needs to be addressed in future.

Sardinian honeys as sources of xanthine oxidase and tyrosinase inhibitors

Sardinian honeys obtained from different floral sources (Arbutus, Asphodelus, Eucalyptus, Thistle, and Sulla) were evaluated for their ability to inhibit tyrosinase and xanthine oxidase enzymes and for their antioxidant activity. Physicochemical parameters, total phenolic, and flavonoids content were also determined. Honey from Arbutus flowers had the highest antioxidant activity followed by Eucalyptus and Thistle ones. These three honeys showed good tyrosinase and xanthine oxidase inhibition properties. Thus, these Sardinian honeys could have a great potential as antioxidant sources for pharmaceutical and cosmetic applications.

Broad-range potential of Asphodelus microcarpus leaves extract for drug development

Background

Many plants have been used in traditional medicine for their antibacterial, antifungal, antiprotozoal, antiviral, antidiarrhoeal, analgesic, antimalarial, antioxidant, anti-inflammatory and anticancer activities.

In order to find novel antimicrobial and antiviral agents, the aim of the present study was the evaluation of the antibacterial and antibiofilm susceptibility of Asphodelus microcarpus leaves extract. Moreover, the antiviral activity and the phytochemical composition of the active extract were also determined.

Methods

Antimicrobial and antibiofilm activities of leaves ethanol extract of A. microcarpus were evaluated on 13 different microbial strains. We selected three different sets of microorganisms: (i) Gram-positive bacteria, (ii) Gram-negative bacteria and (iii) yeasts. The potential antiviral activity of A. microcarpus leaves ethanol extract was evaluated with a luciferase reporter gene assay in which the dsRNA-dependent RIG-I-mediated IFN-β activation was inducted or inhibited by the Ebola virus VP35 protein. HPLC-DAD-MS was used to identify phenolic profile of the active extract.

Results

A. microcarpus leaves extract showed a potent inhibitory activity on Gram-positive bacteria while only a reduced inhibition was observed on Gram-negative bacteria. No activity was detected against Yeasts. The extract also showed an interesting antibiofilm motif on various bacterial strains (E. coli, S. aureus, S. haemolyticus and B. clausii). Moreover, this extract significantly affected the Ebola virus VP35 inhibition of the viral RNA (vRNA) induced IFN response.

Conclusions

The overall results provide supportive data on the use of A. microcarpus as antimicrobial agent and a potential source of anti-viral natural products.

Data collected set the bases for further studies for the identification of single active components and the development of new pharmaceuticals.

Tyrosinase inhibition and antioxidant properties of Asphodelus microcarpus extracts

Background

Asphodelus microcarpus belongs to the family Liliaceae that include several medicinal plants. In the traditional medicine plants of the genus Asphodelus are used to treat skin disorders such as ectodermal parasites, psoriasis, microbial infection and for lightening freckles. In order to find novel skin depigmenting agents, the present work was carry out to evaluate antioxidant activity and tyrosinase inhibitory potential of leaves, flowers and tubers extracts of A. microcarpus. The phytochemical composition of the active extract was also evaluated.

Methods

Three different extracts (water, methanol and ethanol) from leaves, flowers and tubers of A. microcarpus were evaluated for their inhibitory effect on tyrosinase activity using l-3,4-dihydroxyphenylalanine (l-DOPA) as substrate. Inhibition of cellular tyrosinase activity and melanin production was also investigated in melanoma B16F10 cells. Antioxidant activity, total phenolic and flavonoids contents were determined using standard in vitro methods. HPLC-DAD-MS was used to identify phenolic profile of the active extract.

Results

The results showed that all extracts have a direct inhibitory anti-tyrosinase activity, with ethanolic extract from flowers (FEE) exhibiting the stronger effect. Kinetic analysis revealed that FEE acts as an uncompetitive inhibitor with a Ki value of 0.19 mg/mL. The same effect was observed in murine melanoma B16F10 cells. Cellular tyrosinase activity as well as melanin content were reduced in FEE-treated cells. The results were comparable to that of the standard tyrosinase inhibitor (kojic acid). Furthermore, the same extract showed the highest antioxidant activity and an elevated levels of total phenolics and flavonoid content. Eleven phenolic components were identified as chlorogenic acid, luteolin derivates, naringenin and apigenin.

Conclusions

Our findings showed that FEE from A. microcarpus inhibits tyrosinase and exerted antimelanogenesis effect in B16F10 cells. This extract also showed the highest scavenging activity, which could be mainly attributed to its high levels of total polyphenols and flavonoids. These results suggest that A. microcarpus has a great potential as sources of bioactive compounds which could be used as depigmenting agents in skin disorders.

Biological Activities of Aerial Parts Extracts of Euphorbia characias

The aim of the present study was to evaluate antioxidant, antimicrobial, anti-HIV, and cholinesterase inhibitory activities of aqueous and alcoholic extracts from leaves, stems, and flowers of Euphorbia characias. The extracts showed a high antioxidant activity and were a good source of total polyphenols and flavonoids. Ethanolic extracts from leaves and flowers displayed the highest inhibitory activity against acetylcholinesterase and butyrylcholinesterase, showing potential properties against Alzheimer's disease. Antimicrobial assay showed that leaves and flowers extracts were active against all Gram-positive bacteria tested. The ethanolic leaves extract appeared to have the strongest antibacterial activity against Bacillus cereus with MIC value of 312.5 μg/mL followed by Listeria monocytogenes and Staphylococcus aureus that also exhibited good sensitivity with MIC values of 1250 μg/mL. Moreover, all the extracts possessed anti-HIV activity. The ethanolic flower extract was the most potent inhibitor of HIV-1 RT DNA polymerase RNA-dependent and Ribonuclease H with IC50 values of 0.26 and 0.33 μg/mL, respectively. The LC-DAD metabolic profile showed that ethanolic leaves extract contains high levels of quercetin derivatives. This study suggests that Euphorbia characias extracts represent a good source of natural bioactive compounds which could be useful for pharmaceutical application as well as in food system for the prevention of the growth of food-borne bacteria and to extend the shelf-life of processed foods.