Pomegranate Fruit Quality and Seed Drying Method: Effect on the Chemical Composition and Bioactivities of the Extracted Oil

The study presents a comparative investigation of the composition and bioactivity of oil extracted from pomegranate seeds of sun-burned fruit (SB) and healthy fruit (HF) for the value-adding potential of pomegranate fruit waste. Seeds from SB and HF were independently freeze dried, sun dried, and oven dried before ultrasound-assisted oil extraction using petroleum ether. The extracted oil was analysed for yield, refractive index, ρ-anisidine value, total phenolic content (TPC), DPPH radical scavenging ability, antimicrobial activity, tyrosinase enzyme inhibition ability, and fatty acid composition. The results showed that oven dried seeds, regardless of fruit quality, yielded the highest oil (20.85–24.70%, dry weight). Regardless of the seed drying method, oil from the seeds of SB exhibited the highest TPC (1.48–2.84 mgGAE/g PSO) than oil from the seeds of HF. The oil from oven dried and freeze dried seeds of SB were more effective in scavenging the DPPH radicals with IC50 values of 34.77 and 39.97 µg/mL, respectively. All the oil samples showed good ability to inhibit tyrosinase enzyme regardless of fruit quality and seed drying method, with monophenolase and diphenolase IC50 ranging between 0.31 and 0.49 mg/mL and 0.64 and 2.43 mg/mL, respectively. Irrespective of the drying method, oil extracted from HF seeds exhibited greater antimicrobial potency against the tested bacteria. The fatty acid composition of the oil samples was neither affected by fruit quality and seed drying method. Generally, all oil samples exhibited high levels of punicic acid (81.21–82.68%) and low omega 6 to omega 3 ratios (0.19–0.37%), suggesting that the oil samples were healthy. Principal component analysis (PCA) established that freeze dried seeds of SB is an excellent source of oil with higher TPC, punicic acid, polyunsaturated fatty acids, and unsaturated fatty acid/saturated fatty acid ratio. It can be concluded that the seed from SB is a good raw material for oil that can be utilised in cosmetic products formulation.

New Inhibitors of Laccase and Tyrosinase by Examination of Cross-Inhibition between Copper-Containing Enzymes

Coppers play crucial roles in the maintenance homeostasis in living species. Approximately 20 enzyme families of eukaryotes and prokaryotes are known to utilize copper atoms for catalytic activities. However, small-molecule inhibitors directly targeting catalytic centers are rare, except for those that act against tyrosinase and dopamine-β-hydroxylase (DBH). This study tested whether known tyrosinase inhibitors can inhibit the copper-containing enzymes, ceruloplasmin, DBH, and laccase. While most small molecules minimally reduced the activities of ceruloplasmin and DBH, aside from known inhibitors, 5 of 28 tested molecules significantly inhibited the function of laccase, with the Ki values in the range of 15 to 48 µM. Enzyme inhibitory kinetics classified the molecules as competitive inhibitors, whereas differential scanning fluorimetry and fluorescence quenching supported direct bindings. To the best of our knowledge, this is the first report on organic small-molecule inhibitors for laccase. Comparison of tyrosinase and DBH inhibitors using cheminformatics predicted that the presence of thione moiety would suffice to inhibit tyrosinase. Enzyme assays confirmed this prediction, leading to the discovery of two new dual tyrosinase and DBH inhibitors.

Isolation of Arbutin from Leaves and Fruits of Buni (Antidesma Bunius L. Spreng) As Tyrosinase Enzym Inhibitor

Several studies have shown that plant extractive substances have the potential as active compounds inhibiting the enzyme tyrosinase. Arbutin is an enzyme inhibitor of tyrosinase, known as a popular whitening agent used in cosmetics because of its effectiveness in overcoming skin hyperpigmentation. The purpose of this study was to conduct a qualitative and quantitative analysis of arbutin on Buni Leaves and Fruits (Antidesma bunius L. Spreng). The raw simplicia used are mature and young buni leaves, green, red and purple buni fruits. The extraction method is maceration using methanol as solvent. The initial screening for arbutin content was carried out using thin layer chromatography (TLC) and dichlormethan:methanol 50:50 used as mobile phase. Isolation of arbutin content was carried out using Preparative TLC with the same eluent. Qualitative and quantitative analysis were performed using High Pressured Liquid Chromatography (HPLC) with mobile phase of acetonitrile: water 60:40. The tyrosinase enzyme inhibition activity test was then carried out in vitro using 96-well microplate, l-tyrosine and l-dopa were used as substrate at a wavelength of 492 nm. The Rf values obtained ??for mature buni leaves and green buni fruits, respectively 0.61 and 0,62. The retention time of HPLC chromatogram respectively 2,784 minutes and 2,758 minutes. Arbutin levels in leaves and fruits are 7.9 mg / g and 2 mg / g. The activity of the enzyme tyrosinase of mature buni leaves on L-dopa and L-tyrosine substrate were respectively stated as IC50 values ??of 88.7191ppm and 101.33347 ppm. The activity of the enzyme tyrosinase of the green buni fruit on L-dopa and L-tyrosine substrate respectively stated IC50 values ??of 198,0293 ppm and 246,1296 ppm.

Use of Immobilized Enzyme In Granular Activated Carbon And Chitosan Beads For Phenol Removal From Effluents

Tyrosinase enzyme present in a crude extract was immobilized in granular activated carbon (GAC) and activated chitosan beads (ACB). It was possible to immobilize up to 70.0 % of the enzymes in GAC in the conditions of 10.0 g of support, 15.7 rad/s of agitation and 90 minutes of contact time, and 100.0 % of enzymes in ACB when using 5 g of support, agitation of 15.7 rad/s and contact time of 120 minutes. In enzymatic oxidation tests, tyrosinase immobilized in GAC was able to achieve a final phenol concentration below the limit required by Brazilian law, 0.5 mg/L for phenol solutions with an initial concentration up to 20.0 mg/L while the enzyme immobilized in ACB was able to adapt solutions with initial concentrations of phenol up to 40.0 mg /L. It was possible to reuse the enzyme immobilized in GAC 2 times, maintaining the same phenol removal efficiency, while the enzyme immobilized in ACB maintained up to 98.0 % of its efficiency in 5 cycles of enzymatic oxidation of solutions with 10.0 mg/L of phenol initially. It was possible to maintain the same phenol removal efficiency as immobilized enzymes when stored for up to 2 weeks.

The Discovery of Tyrosinase Enzyme Inhibitors Activity from Polyphenolic Compounds in Red Grape Seeds through In Silico Study

Tyrosinases are essential metal-containing enzymes in the biosynthesis of melanin, therefore responsible for pigmentation of the skin. The upregulation of tyrosinase enzyme activities leads to hyperpigmentation that will become a health problems and interfere psychosocially. Inhibition of tyrosinase enzyme activity, both competitive and non-competitive become widely developed for most anti hyperpigmentation agent. Natural antioxidants are one of the potential compounds for this purpose. Red grape seeds contain high levels of antioxidant compounds, such as procyanidin, prodelphinidin, and propelargonidin. In this research in silico studies, including molecular docking, molecular dynamics simulations, and toxicity predictions, were used to assess the activity of the three molecules of polyphenolic compounds on macromolecules of the tyrosinase enzyme. Molecular docking studies show that the compound propelargonidin has the highest affinity against the macromolecule of the tyrosinase enzyme, with a binding free energy value of −32.87 kJ/mol. These results were confirmed in molecular dynamics simulations that show strong interactions at the macromolecular active site of the tyrosinase enzyme. Toxicity prediction results show that the three polyphenolic compound molecules were classified in the High-Class Category, which shows that safety is not guaranteed, but is likely, not carcinogenic and nongenotoxic. Therefore, the compound propelargonidin is predicted to be able to interact strongly with the tyrosinase enzyme. The results in this research are useful for further study in the development of tyrosinase enzyme inhibitors.

Tyrosinase Enzymes Activities and Sun Protection Factor of Ethanol Extract, Water Fraction, and n-Butanol Fraction of Chromolaena odorata L. Leaves

Background: The need for skincare is increasing. One of the indicators of skin health is the brightness of the skin tone. Tyrosinase enzymes can darken the skin color due to their activity against melanin biosynthesis. The skin color will also change when exposed to UV rays, and even at a more severe level, it can cause cancer. Aims: The purpose of this study was to determine the inhibitory activity of the tyrosinase enzyme and the SPF (Sun Protection Factor) value of ethanol extract, water fraction, and n-butanol fraction from Chromolaena odorata L. leaves. Methods: In this study, tests were carried out on ethanol extract, water fraction, and an n-butanol fraction of C. odorata leaves to inhibit tyrosinase enzyme activity based on percent inhibition and determination of inhibitory activity against UV light based on the SPF value. Determination of tyrosinase enzyme inhibitory activity using an ELISA reader was carried out by calculating the IC50 value with kojic acid as a positive control and measuring the SPF value using UV-Vis spectrophotometry. Result: The results showed that the IC50 value of the tyrosinase enzyme inhibitory activity test, kojic acid as a positive control was 24.85 µg/mL (very strong), ethanol extract samples, water fraction, and n-butanol fraction were 191 µg/mL (weak), 65.86 µg/mL (very strong), and 14.59 µg/mL (very strong), respectively. The SPF value, including minimal protection shown by the ethanol extract at a concentration of 60 µg/mL, the water fraction at a 120 µg/mL concentration, and the n-butanol fraction a concentration of 40 µg/mL. Conclusion: The ethanol extract, water fraction, and n-butanol fraction of the Chromolaena odorata L. had an inhibitory effect on the tyrosinase enzyme and sun protection capacity used as an ingredient in cosmetic preparations

The Ethanol Extract of Musa sapientum Linn. Peel Inhibits Melanogenesis through AKT Signaling Pathway

Hyperpigmentation caused by melanin overproduction can be induced by UV radiation. The quest for effective depigmenting agents continues because many anti-melanin agents have restricted use and/or produce side-effects. The present study was aimed to investigate the inhibitory activity of Musa sapientum Linn. (AA group) peel ethanol extracts (MPE) on α-melanocyte stimulating hormone (α-MSH)-induced melanin production. In addition, the molecular mechanism related to this process was examined in B16F10 mouse melanoma cells. The results indicated that MPE remarkably inhibited melanogenesis in α-MSH-stimulated B16F10 cells. Microphthalmia-associated transcription factor (MITF) and tyrosinase expressions were suppressed by MPE in a concentration-dependent manner. In addition, MPE significantly decreased the expression of melanosome transfer protein markers (Rab27a and Pmel17) in a dose-dependent manner. This study found that the elevated phosphorylation of AKT in the B16F10 cells was diminished by MPE treatment. Furthermore, microtubule-associated protein 1 light chain 3 (LC3)-II and p62 (autophagy markers) were affected after the B16F10 cells were treated with MPE. This study demonstrated that MPE might be an effective agent for anti-melanogenesis through the AKT pathway, subsequently diminishing MITF expression and tyrosinase enzyme family production. The findings indicated that MPE could potentially serve as a depigmenting agent in cosmeceuticals.

Enzymatic Digestion of Calf Fleshing Meat By-Products: Antioxidant and Anti-Tyrosinase Activity of Protein Hydrolysates, and Identification of Fatty Acids

The food waste reduction through an efficient recovery of its valuable building molecules has become an important topic with a positive effect on the economy and the environment. In this work, the revalorization of slaughterhouse calf fleshing meat through its enzymatic hydrolysis is proposed. The proteolytic activity of 11 enzymes was initially screened and the four most efficient enzymes (papain, trypsin, pancreatin, and bromelain) were selected. The molecular profiling of the different protein/peptide fractions by the Linear Trap Quadrupole-OrbiTrap technique showed compositional differences due to the specificity of the enzymes’ cleavage sites. In order to find a potential reuse of these hydrolysates, the analysis of antioxidant and, for the first time on fleshing meat hydrolysates, of anti-tyrosinase activities, was performed. Papain-digested samples were those showing the highest inhibition activity of tyrosinase enzyme (55.6%) as well as the highest antioxidant activity (3.52 g TEAC/L). In addition, the composition analysis of the lipid fraction was performed. The mono-unsaturated fatty acids resulted to be the most abundant lipid in all the samples with the exception of pancreatin-treated hydrolysates in which poly-unsaturated fatty acids were predominant. The present results seemed to support a possible valorization of isolated fractions from calf fleshing by-products, as food or feed ingredients, by the implementation of fraction isolation within the meat-processing pipeline.