Dysregulation of tyrosinase activity: a potential link between skin disorders and neurodegeneration.

OBJECTIVES: The co-occurrence of melanoma and Parkinson's disease (PD) is higher than expected. We review the relationship between melanoma and PD, then proffer a hypothesis of how dysregulated human tyrosinase could be involved in both diseases via the loss of dopamine and neuromelanin-positive neurons in PD and the genesis alterations in melanin content during melanoma. KEY FINDINGS: There are a surprising number of links between skin disorders and neurodegenerative diseases. Some risk factors related to the co-occurrence of PD and melanoma have been extensively investigated over the past 15 years. It has been proposed that human tyrosinase, an enzyme participating in the biosynthesis of neuromelanin in the brain and of melanin in the skin, plays a role. Abnormally dysregulated human tyrosinase impacts the genesis and progression of melanoma and PD. SUMMARY: The dual role of human tyrosinase places it as the potential critical link between these seemingly distinct conditions. Detecting and monitoring human tyrosinase activity in the progression of melanoma and PD opens new opportunities for early diagnosis and treatment of both diseases.

Risk Factors for Heart Disease in Working Railwaymen.

Heart diseases are the most common non-communicable diseases worldwide. We examined the prevalence of risk factors for heart disease among a sub-population of working men. In total, 11,059 railway crew workers of the Russian Railways Company were included in the study. We also asked participants to answer several questions based on the WHO STEPwise approach to surveillance (STEPS) translated into Russian. Only 30% of drivers had normal body mass index (BMI), whereas 70% were overweight or obese. In 12% of subjects, total cholesterol was higher than 5 mmol/L. In 15% of participants, glucose level was higher than 5.5 mmol/L. 38% of drivers reported smoking. Physical inactivity was registered in 54% of persons. Only 29% ate according to the key principles of good diet quality. 24% of respondents had a family history of heart disease. MANOVA demonstrated that BMI was determined by age, profession, smoking, physical inactivity, and diet quality. As age increased, the number of people with normal cholesterol levels decreased. It was demonstrated that a correlation existed between glucose levels and BMI. In the total group, the correlation was 0.46 (p < .05). The correlation between those parameters increased due to age, from 0.33 in the <30 years of age group up to 0.52 in the >50 years of age group. This study demonstrated that there is a high prevalence of risk factors for heart disease in train drivers in the Russian Federation.

Engineering indel and substitution variants of diverse and ancient enzymes using Graphical Representation of Ancestral Sequence Predictions (GRASP).

Ancestral sequence reconstruction is a technique that is gaining widespread use in molecular evolution studies and protein engineering. Accurate reconstruction requires the ability to handle appropriately large numbers of sequences, as well as insertion and deletion (indel) events, but available approaches exhibit limitations. To address these limitations, we developed Graphical Representation of Ancestral Sequence Predictions (GRASP), which efficiently implements maximum likelihood methods to enable the inference of ancestors of families with more than 10,000 members. GRASP implements partial order graphs (POGs) to represent and infer insertion and deletion events across ancestors, enabling the identification of building blocks for protein engineering. To validate the capacity to engineer novel proteins from realistic data, we predicted ancestor sequences across three distinct enzyme families: glucose-methanol-choline (GMC) oxidoreductases, cytochromes P450, and dihydroxy/sugar acid dehydratases (DHAD). All tested ancestors demonstrated enzymatic activity. Our study demonstrates the ability of GRASP (1) to support large data sets over 10,000 sequences and (2) to employ insertions and deletions to identify building blocks for engineering biologically active ancestors, by exploring variation over evolutionary time.

Antiinflammatory and Anticancer Properties of Grewia asiatica Crude Extracts and Fractions: A Bioassay-Guided Approach.

The study was an extension of our earlier work on antiinflammatory and anticancer properties of G. asiatica fruit. We aimed to develop a bioassay guided multistep purification technique for producing bioactive fractions of G. asiatica crude extracts. Dried fruit powder was sequentially fractionated with 100% dichloromethane, 100% methanol (MeOH), and 50% MeOH. Active extracts were subjected to liquid-liquid partitioning followed by subfractionation using RP-HPLC. Antioxidant, antiinflammatory, and anticancer activities of the fruit extracts, and their potent fractions were evaluated in vitro, while identification of compounds from the bioactive fractions was performed by ESI-MS/MS analysis. The amount of the identified compounds present was confirmed using external standards adopting a simple, accurate, and rapid analytical HPLC method. The results showed that 100% and 50% MeOH extracts possessed bioactivity; one of which (the 50% MeOH extract) displayed potent activity in all in vitro bioassays. MeOH extract (50%) derived fraction C and hydroalcoholic fraction 5 (GAHAF5) were observed to possess higher antioxidant, antiinflammatory, and in vitro anticancer activity. IC50 of GAHAF5 against MCF-7, HEp-2, and NCI-H522 cancer cells was recorded as 26.2, 51.4, and 63 µg/mL, respectively. ESI-MS/MS and HPLC analysis identified catechin, chlorogenic acid, caffeic acid, and morin as potential bioactive compounds in the GAHAF5 fraction with concentrations of 1230, 491, 957, and 130 µg/g, respectively. The findings indicated that G. asiatica bioactive fractions possessed antiinflammatory activity in vitro and were cytotoxic against breast cancer, lung cancer, and laryngeal cancer cell lines.

Phytochemical Profile, Biological Properties, and Food Applications of the Medicinal Plant Syzygium cumini.

Syzygium cumini, locally known as Jamun in Asia, is a fruit-bearing crop belonging to the Myrtaceae family. This study aims to summarize the most recent literature related to botany, traditional applications, phytochemical ingredients, pharmacological activities, nutrition, and potential food applications of S. cumini. Traditionally, S. cumini has been utilized to combat diabetes and dysentery, and it is given to females with a history of abortions. Anatomical parts of S. cumini exhibit therapeutic potentials including antioxidant, anti-inflammatory, analgesic, antipyretic, antimalarial, anticancer, and antidiabetic activities attributed to the presence of various primary and secondary metabolites such as carbohydrates, proteins, amino acids, alkaloids, flavonoids (i.e., quercetin, myricetin, kaempferol), phenolic acids (gallic acid, caffeic acid, ellagic acid) and anthocyanins (delphinidin-3,5-O-diglucoside, petunidin-3,5-O-diglucoside, malvidin-3,5-O-diglucoside). Different fruit parts of S. cumini have been employed to enhance the nutritional and overall quality of jams, jellies, wines, and fermented products. Today, S. cumini is also used in edible films. So, we believe that S. cumini's anatomical parts, extracts, and isolated compounds can be used in the food industry with applications in food packaging and as food additives. Future research should focus on the isolation and purification of compounds from S. cumini to treat various disorders. More importantly, clinical trials are required to develop low-cost medications with a low therapeutic index.

The Chemical Composition and Health-Promoting Effects of the Grewia Species-A Systematic Review and Meta-Analysis.

Globally grown and organoleptically appreciated Grewia species are known as sources of bioactive compounds that avert the risk of communicable and non-communicable diseases. Therefore, in recent years, the genus Grewia has attracted increasing scientific attention. This is the first systematic review which focusses primarily on the nutritional composition, phytochemical profile, pharmacological properties, and disease preventative role of Grewia species. The literature published from 1975 to 2021 was searched to retrieve relevant articles from databases such as Google Scholar, Scopus, PubMed, and Web of Science. Two independent reviewers carried out the screening, selection of articles, and data extraction. Of 815 references, 56 met our inclusion criteria. G. asiatica and G. optiva were the most frequently studied species. We found 167 chemical compounds from 12 Grewia species, allocated to 21 categories. Flavonoids represented 41.31% of the reported bioactive compounds, followed by protein and amino acids (10.7%), fats and fatty acids (9.58%), ash and minerals (6.58%), and non-flavonoid polyphenols (5.96%). Crude extracts, enriched with bioactive compounds, and isolated compounds from the Grewia species show antioxidant, anticancer, anti-inflammatory, antidiabetic, hepatoprotective/radioprotective, immunomodulatory, and sedative hypnotic potential. Moreover, antimicrobial properties, improvement in learning and memory deficits, and effectiveness against neurodegenerative ailments are also described within the reviewed article. Nowadays, the side effects of some synthetic drugs and therapies, and bottlenecks in the drug development pathway have directed the attention of researchers and pharmaceutical industries towards the development of new products that are safe, cost-effective, and readily available. However, the application of the Grewia species in pharmaceutical industries is still limited.

Computational modeling - an approach to the development of blood grouping reagents.

Introduction: Blood group antigens are defined by an immune response that generates antibodies against a red blood cell molecule. Antibodies against these antigens can be associated with hemolytic transfusion reactions. However, difficulties can arise when developing antibodies against antigens through the use of peptide sequences alone. Three-dimensional representations (models) of the molecular structure of antigen-bearing proteins can provide valuable insights into tertiary structures and their consequent antigenicity. This can be achieved through predictive computational modeling to produce both structural and molecular dynamics models of blood group proteins.Areas covered: Authors discuss the use of molecular dynamic simulations on existing structures, as well as the use of computational modeling techniques in the development of protein models lacking preexisting data. Finally, the authors discuss specific examples of the use of computationally derived models of the MNS blood group system and its use in attempts to produce antibodies against MNS proteins.Expert opinion: Although in silico techniques have limitations, computer-based predictive models can inform the direction of research into blood group proteins. It is to be expected that as computer-based techniques grow more powerful these contributions will be even more significant.

Syzygium cumini(L.),Skeels fruit extracts: In vitro and in vivo anti-inflammatory properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Syzygium cumini (L.) Skeels is an important medicinal plant utilized in the health care systems of Pakistan, India, Sri Lanka, and Bangladesh. S. cumini have been used to treat renal issues, indigestion, diabetes, dysentery, and employed in folk medicine to treat inflammations. It is known to anticipate antioxidant, anti-inflammatory, anticancer, anti-diabetic, anti-bacterial, antifungal, activities, and radioprotective activities. MATERIAL AND METHODS: We examined the in vitro anti-inflammatory activities of S. cumini fruit extracts, evaluated using membrane stabilization, egg albumin denaturation, and bovine serum albumin denaturation assays. In vivo anti-inflammatory activity was also assessed, using murine models of carrageenan, formaldehyde, and PGE2 induced paw edema. Fractionation of active extracts was performed using HPLC, followed by LC-ESI-MS/MS analysis to identify the bioactive compounds responsible for anti-inflammatory activity. RESULTS: The crude methanolic extract showed stronger in vitro and in vivo anti-inflammatory activities compared to other extracts. The most potent effects were observed in the formaldehyde induced paw edema assay wherein methanolic extract and standard indomethacin induced 72% and 88% inhibition against paw edema volume in comparison to control (normal saline) respectively. In the bovine serum albumin denaturation assay the methanolic extract induced 82% inhibition against denaturation as compared to control (phosphate buffer) while standard diclofenac sodium induced 98% inhibition. In contrast, 50% v/v MeOH:H2O or 100% dichloromethane extracts displayed moderate to weak effects in the anti-inflammatory models. HPLC fractionation provided 6 active sub-fractions, four (MF2, MF3, MF6, MF7) from the 100% methanolic extract and two (HAF1, HAF3) from the 50% methanolic extract. The MF2, MF7, and HAF1 sub-fractions displayed potent activity in all studied in vitro assays. LC-ESI-MS-MS analysis tentatively identified delphinidin 3-glucoside, peonidin-3,5-diglucoside, gallic acid, liquitrigenin, scopoletin, umbelliferon, and rosmanol from the 100% methanolic fractions. Myricetin, catechin, quinic acid, chlorogenic acid, ellagic acid, gallic acid, and caffeic acid were identified in the 50% methanolic fractions. CONCLUSIONS: These results demonstrate that S. cumini fruit extracts are a rich source of bioactive compounds that are worthy of further investigation as leads for anti-inflammatory drug discovery.

Aggregates in blood filter chambers used from the plasma donations of anti-D donors: evaluation for monoclonal antibody discovery using phage display.

BACKGROUND: RhD-immunoglobulin (RhIg) prevents anti-D alloimmunisation in D-negative pregnant women when the fetus is D-positive, reducing the incidence of haemolytic disease of the fetus and newborn. Manufacturing RhIg is reliant on the limited supply of plasma donations with anti-D antibodies. Monoclonal antibody (mAb) development platforms such as phage display, require blood samples to be collected from anti-D donors, which may be a complicated process. The blood filter chamber (BFC) discarded after an anti-D donor's donation might provide a source of Ig-encoding RNA. This study aims to evaluate whether used BFCs are a suitable source of Ig-encoding RNA for phage display. MATERIAL AND METHODS: Haemonetics PCS2 BFCs were obtained from 10 anti-D donors for total RNA extraction, cDNA synthesis and amplification of VH and VL IgG sequences for assembly of single-chain variable fragments (scFvs). A scFv-phage display library was constructed and 3 rounds of biopanning were performed using D-positive and D-negative red blood cells (RBCs). Positive phage clones were isolated, Sanger sequenced and, where possible, reformatted into full-length human IgGs to define specificity. The BFC aggregates from 2 anti-D donors underwent a Wright-Giemsa stain and hematological cell count. RESULTS: Of 10 BFCs, a sufficient yield of total RNA for library construction was obtained from BFCs containing cellular aggregates (n=5). Aggregate analysis showed lymphocytes were the cellular source of Ig-encoding RNA. From the 5 samples with aggregates, scFvs were assembled from amplified IgG variable regions. The library constructed from 1 of these samples resulted in the isolation of clones binding to D-positive RBCs with IGHV3 gene usage. Of the 4 reformatted IgG, 3 were anti-D and 1 had undefined specificity. DISCUSSION: BFC aggregates are a new and convenient source of Ig-encoding RNA which can be used to construct Ig gene libraries for mAb isolation and discovery via antibody phage display.

Tyrosinase inhibitors as potential antibacterial agents.

Tyrosinase is a copper-containing enzyme that catalyzes the biosynthesis of melanin. This enzyme is present in bacteria, fungi, plants and animals, and plays multiple roles in pigmentation, wound healing, radiation protection, primary immune responses and the undesirable browning of fruits and vegetables. Selective tyrosinase inhibitors hence have potential application in diverse areas of agriculture, cosmetics and pharmaceuticals. In the past decade many natural and synthetic tyrosinase inhibitors have been evaluated, with many reported to also possess intrinsic antibacterial activity. Further, the enzyme product melanin has been shown to compromise the activity of traditional antibiotics. Due to the antibiotic resistance crisis and the slow development of new antibiotics, tyrosinase inhibitors may have potential for development of novel antimicrobials or antibiotic adjuvants that enhance activity of incumbent drugs. This review focuses on the antibacterial activity of natural and synthetic tyrosinase inhibitors reported in the past ten years and explores the possibilities for synergism of anti-tyrosinase with anti-bacterials.

Hydroxyl substituted benzoic acid/cinnamic acid derivatives: Tyrosinase inhibitory kinetics, anti-melanogenic activity and molecular docking studies.

The inhibition of tyrosinase is an established strategy for treating hyperpigmentation. Our previous findings demonstrated that cinnamic acid and benzoic acid scaffolds can be effective tyrosinase inhibitors with low toxicity. The hydroxyl substituted benzoic and cinnamic acid moieties of these precursors were incorporated into new chemotypes that displayed in vitro inhibitory effect against mushroom tyrosinase. The most active compound, (2-(3-methoxyphenoxy)-2-oxoethyl (E)-3-(4-hydroxyphenyl) acrylate) 6c, inhibited tyrosinase with an IC50 of 5.7 µM, while (2-(3-methoxyphenoxy)-2-oxoethyl 2, 4-dihydroxybenzoate) 4d had an IC50 of 23.8 µM. In comparison, the positive control, kojic acid showed tyrosinase inhibition with an IC50 = 16.7 µM. Analysis of enzyme kinetics revealed that 6c and 4d displayed noncompetitive reversible inhibition of the second tyrosinase enzymatic reaction with Ki values of 11 µM and 130 µM respectively. In silico docking studies with mushroom tyrosinase (PDB ID 2Y9X) predicted possible binding modes in the catalytic site for these active compounds. The phenolic para-hydroxy group of the most active compound 6c is predicted to interact with the catalytic site Cu++ ion. The methoxy part of this compound is predicted to form a hydrogen bond with Arg 268. Compound 6c had no observable toxic effects on cell morphology or cell viability at the highest tested concentration of 91.4 µM. When dosed at 91.4 µM onto B16F10 melanoma cells in vitro6c showed anti-melanogenic effects equivalent to kojic acid at 880 µM. 6c displayed no PAINS (pan-assay interference compounds) alerts. Our results show that compound 6c is a more potent tyrosinase inhibitor than kojic acid and is a candidate for further development. Our exposition of the details of the interactions between 6c and the catalytic pocket of tyrosinase provides a basis for rational design of additional potent inhibitors of tyrosinase, built on the cinnamic acid scaffold.