On the Novel Process of Pristine Microplastic Bio-fragmentation by Zebrafish (Danio rerio).

Microplastics are highly persistent particles that deliberately contaminate our ecosystem. These small-sized particles can pass through filtering systems into the water bodies, affecting various forms of aquatic and terrestrial life. However, little is known about their fragmentation process within the organism's body. In previous studies, commercially available microplastics were used that are rarely found in the environment naturally, hence they cannot mimic the effects on our surroundings. Therefore, using the zebrafish, Danio rerio we have evaluated the process of bio-fragmentation of ingested pristine polyethene microplastics which are widely used in our daily life. We have also examined their faecal pellets through Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). Our results show that zebrafish can potentially bio-fragment the pristine microplastic particles into nano-plastic within a short period of 24 h. Additionally, zebrafish cannot recognize the pristine microplastic particles and can ingest them as food. No mortality occurred during the experiment. Thus, we have identified a natural pathway of microplastic bio-fragmentation, introducing an emerging role of zebrafish in biogeochemical cycling and the fate of plastics.

Isocyanate induces cytotoxicity via activation of phosphorylated alpha synuclein protein, nitrosative stress, and apoptotic pathway in Parkinson's Disease model-SHSY-5Y cells.

BACKGROUND: Neurotoxic disorders account for a significant portion of the diseases that influence the worldwide disease burden. Parkinson's disease is one such disease that is linked with environmental toxin exposure. Isocyanates are a highly reactive industrial intermediate used widely in manufacturing plastic products, paints, etc. This study aims to delineate the neurotoxic potential of isocyanate in Parkinson's cell model-SHSY-5Y cells. METHODOLOGY: SHSY-5Y cells were treated with isocyanate analogue (N succinimidyl N methyl carbamate) in time and dose dependant manner. Different parameters were assessed like protein expression, nitrosative stress level, antioxidant enzymes level and apoptosis. RESULTS: Our findings demonstrate that dose- and time-dependent isocyanate exposure increases reactive nitrogen species and decreases the glutathione, SOD, and catalase levels. Further, increased phosphorylated alpha-synuclein protein and activation of caspase 3 exert cytotoxicity in SHSY-5Y cells. CONCLUSION: Our research reveals that widely used isocyanate induces cytotoxicity, apoptosis, nitrosative stress, and protein dysfunction, which might constitute a potential mechanism of neurodegeneration in Parkinsonism.

Biodegradation of low density polyethylene (LDPE) by mesophilic fungus 'Penicillium citrinum' isolated from soils of plastic waste dump yard, Bhopal, India.

Low density Polyethylene (LDPE) in various forms has become a part of life. Its accretion due to non degradable nature is concern, endangering life on earth. Amongst various methods of LDPE disposal bioremediation is regarded as ecofriendly & widely accepted. Current investigation was an attempt to isolate potent PE degrading fungus from municipal landfill soils of Bhopal, India loaded with plastic waste.16 fungal isolates were recorded from the site; PE deteriorating fungus was screened using mineral salt agar medium amended with 3% LDPE powder as sole carbon source. The isolate Penicillium citrinum showed fast fungal colony growth in screening medium was selected for biodegradation study. P.citrinum showed 38.82 ± 1.08% weight loss of untreated LDPE pieces; to improve the degradation capacity nitric acid pretreatment was performed; biodegradation was significantly stimulated by 47.22 ± 2.04% after it's pretreatment. Laccase, lipase, esterase & manganese peroxidase activities were assayed by spectrophotometer. LDPE biodegradation was analyzed by weight loss %, change in pH during fungal growth, field emission scanning electron microscopy (FE-SEM), fourier transform infrared spectroscopy (FTIR) & thermogravimetric analysis (TGA). FTIR spectra showed appearance of new functional groups assigned to hydrocarbon biodegradation, confirming enzymatic role in process. Changes in FTIR spectra of LDPE samples (untreated & pretreated) before & after biodegradation & surface changes in the biodegraded LDPE (indicated from FE-SEM) confirmed depolymerization of LDPE. Further changes in thermal decomposition rates of biodegraded samples in comparison to control, validate biodegradation. This is the first report signifying high competence of P.citrinum in LDPE degradation without prior pretreatment.

Natural Tyrosinase Inhibitors: Role of Herbals in the Treatment of Hyperpigmentary Disorders.

Cutaneous pigmentation plays critical role in determining the color of skin along with photo protection of skin from dreadful effects of ultraviolet radiations. Conversely, abnormal accumulation of melanin is responsible for hyper pigmentary disorders such as melasma, senile lentigines and freckles. Because of the visible nature of dermatologic diseases, they have a considerable psychosomatic effect on affected patients. Tyrosinase inhibitors are molecules that interrelate in some way with the enzyme to prevent it from working in the normal manner. Past many decades witnessed the quest for the development of natural tyrosinase inhibitors due to imperative role played by tyrosinase in the process of melanogenesis and fungi or fruit enzymatic browning. Mechanism of pigmentation is characterized by the intact process of the synthesis of specialized black pigment within melanosomes. Melanin is synthesized by a cascade of enzymatic and chemical reactions. For this reason, melanin production is mainly controlled by the expression and activation of tyrosinase. In the current article, we discussed tyrosinase inhibitors from the natural sources, which can be an essential constituent of cosmetics products and depigmenting agents for the treatment of hyperpigmentory disorders.

Insight into Mechanistic Action of Thymoquinone Induced Melanogenesis in Cultured Melanocytes.

BACKGROUND: Melanin plays a crucial role in camouflage, social communication and protection against harmful ultraviolet radiations. Melanin is synthesized by melanocytes through melanogenesis and several intrinsic and extrinsic factors are involved during the process. Any change occuring in the normal melanogenesis process can cause severe pigmentation problems of hypopigmentation or hyperpigmentation. OBJECTIVE: The present study is based on the evaluation of the effect of thymoquinone on melanogenesis and their possible mechanism of action using the B16F10 melanoma cell line for the production via blocking signaling pathways. METHODS: Phase contrast microscopy, cell viability, tyrosinase activity, melanin content and western blot analysis were used in the present study. RESULTS: In the present investigation, cultured melanocytes exhibit that the stimulation of melanin synthesis when treated with thymoquinone. Tyrosinase activity and melanin production in B16F10 melanoma cell line was increased in doze-dependent manner. In western blot, we investigated the involvement of the cAMP/PKA pathway in thymoquinone induced melanogenesis. It was observed protein kinase inhibitors PKA, PKC, PKB and MEK1 decreased the stimulatory effects of thymoquinone from 11.45- fold value to 8.312, 6.631, 4.51, and 7.211-fold value, respectively. However, the results also prove that thymoquinone may partially induce tyrosinase expression via PKA, PKB, PKC and MEK1 signaling pathways. CONCLUSION: The present finding proposed that thymoquinone is a protective challenger for melanogenesis and it might be useful for the treatment of hypopigmentary disorders.

Biochemical aspects of mammalian melanocytes and the emerging role of melanocyte stem cells in dermatological therapies.

Skin color in animals is richer than human beings and is determined by different types of pigments. Melanin is the key pigment responsible for the diverse pigmentation found in animal and human skin, hair, and eyes. Melanin pigment is synthesized by melanocytes and is consecutively transferred to adjacent keratinocytes; here, it acts as an internal sunscreen to defend from ultraviolet (UV) damage. Any defect in the process of melanocytes development and/or melanin synthesis results in esthetic problem of abnormal pigmentation. Clinically, abnormal pigmentation displays distinct increased or reduced pigment levels, known as hyperpigmentation or hypopigmentation. These defects affect either the melanocyte number or its function. Herein, we discuss the fundamental aspects of melanocytes/melanin biology taken together the underlying cause of pigmentary disorders. The current chapter also gives an insight into the melanocyte stem cells biology, which in turn can facilitate the development of novel treatment regimens for dermatological disorders.

Purified Mushroom Tyrosinase Induced Melanogenic Protein Expression in B16F10 Melanocytes: A Quantitative Densitometric Analysis.

BACKGROUND: Human skin exists in a wide range of different colors and gradations, ranging from white to brown to black. This is due to the presence of a chemically inert and stable pigment known as melanin, which is produced deep inside the skin but is displayed as a mosaic at the surface of the body. METHODS & MATERIALS: In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on the effect of purified tyrosinase of Agaricus bisporus on B16F10 melanocytes for melanogenic protein expression. RESULTS: After the treatment of purified tyrosinase B16F10 melanocytes did not show any cytotoxic effect. Melanin content in B16F10 melanocytes was increased by purified tyrosinase in a dose-dependent manner. Quantitative western blot analysis revealed that cellular tyrosinase intensity was enhanced after treatment with purified tyrosinase for 48 hours, where the band intensity had a steady increase in the absorption of purified tyrosinase in B16F10 cells. The density analysis described increased absorption for 2 to 5 bands as 2.7, 3.7, 6.7 and 8.6% respectively. The bands in the comparative analysis of western blot were between the Rf value range (0.40-0.57) with maximum absorption of 3000 intensity curve at 32µg/mL, rather than higher concentration 64µg/mL, showing a decrease in the absorption. CONCLUSION: It is presumed that purified tyrosinase can be used as contestants for the treatment of vitiligous skin conditions.

Links between the Prophet Muhammad (PBUH) recommended foods and disease management: A review in the light of modern superfoods.

Nutrition and other bioactive natural products present in specific foods within a balanced diet play an indispensable role in maintaining and promoting human health. Plants are rich sources of a balanced nutrition because of high content of bioactive products; hence, most of them recently have acquired the status of superfoods. It has been used since ancient times for the treatment of various ailments, and these traditional medicines still remain as one of the most affordable and easily accessible sources of treatment in the primary health-care system. The scientifically based use of these superfoods date back to the era of Prophet Muhammad along with other historical uses of plant products. Prescription of a large number of herbal foods such as dates, pomegranate, olives, figs, grapes, and black seeds was successfully proposed by him. These recently have become superfoods with their powerful healing properties and act as favorable dietary interventions for disease prevention as well as for the good maintenance of health. The use of these foods as ingredients of natural origin with fewer side effects seems to be more favorable than the chemical treatment, which is often complicated. The present review is an attempt to provide a brief survey of the literature on scientifically based significance of these superfoods carried out by various researchers and exploration of a wide spectrum of their pharmacological actions which include antidiabetic, anticancer, immune modulator, analgesic, anti-inflammatory, and hepatoprotective properties.

Melanogenic effect of purified mushroom tyrosinase on B16F10 Melanocytes: A Phase Contrast and Immunofluorescence Microscopic Study.

Cutaneous melanin pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. It has been proven that tyrosinase plays a pivotal role in melanocytes dendrite formation; however, the molecular mechanism underlying this process has not been fully elucidated. The morphological changes were observed under a phase contrast microscope. These changes were evident, with globular cell bodies and increased numbers of tree branch-like dendrites. The present work aimed to study the morphoanatomic effects of purified tyrosinase to determine its skin-darkening potential using B16F10 melanocyte, which has not been done to date. Phase contrast and immunofluorescence microscopic analysis of B16F10 melanocytes has been done after treatment with various concentrations of purified tyrosinase along with standard tyrosinase (Sigma) in order to explore the mechanism of action of purified tyrosinase induced skin darkening. The phase contrast microscopic results showed that the number of melanocytes with melanin-loaded dendrites has increased significantly in purified tyrosinase treated cells in a dose dependent manner leading to skin darkening. In addition, immunofluorescence microscopic analysis revealed purified tyrosinase increase cellular tyrosinase expression in doze dependent manner due to tyrosinase absorption in B16F10 melanocyte. Present findings proved that purified tyrosinase possesses a skin darkening potential and could be used as a safe melanogenic agent for the treatment of hypopigmentation disorders or vitiligo.

Recent Updates in Melanocyte Function: The Use of Promising Bioactive Compounds for the Treatment of Hypopigmentary Disorders.

BACKGROUND: Skin pigmentation is a broadly appearing phenomenon in nature which plays an important task of determining the appearance and biology of all vertebrates including human beings. Skin color is a crucial attribute, determined by the synthesis of melanin pigment within melanocytes by the process of melanogenesis and is regulated by many extrinsic as well as intrinsic factors. Tyrosinase catalyzes the key step of melanogenesis, dysfunction of tyrosinase leads to reduce melanin production which results in severe clinical and aesthetical problems of hypopigmentation. Therefore, the regulation of melanin production is an important strategy in the treatment of abnormal skin pigmentation for cosmetic and medicinal purpose. METHOD: The present review covers the various aspects of mammalian melanocyte biology which will help in the identification of key regulators of melanogenesis from pharmaceutical and pharmacological point of view. Further sections of the review focus on the dysfunctions of melanogenic pathways, which result in severe clinical and aesthetical problems of hypopigmentation. CONCLUSION: We have also attempted to highlight the ability of available scientifically validated plant extracts to naturally enhance melanin synthesis in order to cure hypopigmentation.

Effect of Purified Mushroom Tyrosinase on Melanin Content and Melanogenic Protein Expression.

In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocytes showed that the stimulation of melanogenesis by purified tyrosinase is due to increased tyrosinase absorption. Cellular tyrosinase activity and melanin content in B16F10 melanocytes were increased by purified tyrosinase in a dose-dependent manner. Western blot analysis revealed that cellular tyrosinase levels were enhanced after treatment with purified tyrosinase for 48 hours. Furthermore, tyrosinase induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner. The purified tyrosinase-mediated increase of tyrosinase activity was significantly attenuated by H89, LY294002, Ro-32-0432, and PD98059, cAMP-dependent protein kinase inhibitors. The results indicate that purified tyrosinase can be used as contestant for the treatment of vitiligous skin conditions.

Understanding the ultrastructural aspects of berberine-induced skin-darkening activity in the toad, Bufo melanostictus, melanophores.

Berberine is an active compound of Berberis vulgaris (Daruhaldi) with known multiple pharmacological activities, including antimicrobial, antiviral, anti-inflammatory, cholesterol-lowering, and anticancer effects. The present work aimed to study the ultrastructural effects of berberine to determine its skin-darkening potential using Bufo melanostictus melanophores, which has not been done to date. Light and electron microscopic analysis of isolated dorsal skin melanophores of B. melanostictus has been done after treatment with various concentrations of berberine, along with specific antagonists and agonists of ß-adrenoceptors in order to explore the mechanism of action of berberine-induced skin darkening. The results showed that the number of melanophores with melanin-loaded dendrites increased in the subepidermal layer significantly in berberine-treated skin pieces in a dose-dependent manner leading to skin darkening. Highly electron-dense melanosomes of Stage IV increased considerably due to the enhanced process of melanization. These effects were found to be antagonized by propranolol, and were also found to be highly potentiated by isoprenaline, which is a specific ß-adrenoceptor agonist. The findings show that berberine possesses a skin-darkening potential and could be used as a safe melanogenic agent for the treatment of hypopigmentation disorders or vitiligo.

Purification and characterization of melanogenic enzyme tyrosinase from button mushroom.

Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis. Since the discovery of its melanogenic properties, tyrosinase has been in prime focus and microbial sources of the enzyme are sought. Agaricus bisporus widely known as the common edible mushroom, it's taking place in high amounts of proteins, enzyme, carbohydrates, fibers, and low fat contents are frequently cited in the literature in relation to their nutritional value. In the present study tyrosinase from Agaricus bisporus was purified by ammonium sulphate precipitation, dialysis followed by gel filtration chromatography on Sephadex G-100, and ion exchange chromatography on DEAE-Cellulose; the enzyme was purified, 16.36-fold to give 26.6% yield on total activity in the crude extract and final specific activity of 52.19 U/mg. The SDS-PAGE electrophoresis showed a migrating protein band molecular weight of 95 kDa. The purified tyrosinase was optimized and the results revealed that the optimum values are pH 7.0 and temperature 35°C. The highest activity was reported towards its natural substrate, L-DOPA, with an apparent Km value of 0.933 mM. This indicated that tyrosinase purified from Agaricus bisporus is a potential source for medical applications.

Microbial tyrosinases: promising enzymes for pharmaceutical, food bioprocessing, and environmental industry.

Tyrosinase is a natural enzyme and is often purified to only a low degree and it is involved in a variety of functions which mainly catalyse the o-hydroxylation of monophenols into their corresponding o-diphenols and the oxidation of o-diphenols to o-quinones using molecular oxygen, which then polymerizes to form brown or black pigments. The synthesis of o-diphenols is a potentially valuable catalytic ability and thus tyrosinase has attracted a lot of attention with respect to industrial applications. In environmental technology it is used for the detoxification of phenol-containing wastewaters and contaminated soils, as biosensors for phenol monitoring, and for the production of L-DOPA in pharmaceutical industries, and is also used in cosmetic and food industries as important catalytic enzyme. Melanin pigment synthesized by tyrosinase has found applications for protection against radiation cation exchangers, drug carriers, antioxidants, antiviral agents, or immunogen. The recombinant V. spinosum tryosinase protein can be used to produce tailor-made melanin and other polyphenolic materials using various phenols and catechols as starting materials. This review compiles the recent data on biochemical and molecular properties of microbial tyrosinases, underlining their importance in the industrial use of these enzymes. After that, their most promising applications in pharmaceutical, food processing, and environmental fields are presented.

Cellular interplay among Th17, Th1, and Treg cells in HIV-1 subtype "C" infection.

CD4 T cell depletion is central to HIV pathogenesis and disease progression. Different subsets of CD4 T cells cooperate to combat an infection. Therefore, the immune balance among Th17, Th1, and Treg cells may be critical in HIV immunopathogenesis which is not adequately defined yet. The impact of HIV-1 infection on the interplay of Th17/Th1/Treg cells in HIV-1 infected Indian individuals was examined in the present study and report that HIV-1 Gag specific peripheral blood Th17 cells were significantly depleted in late infected subjects, compared to early infected subjects and slow progressors. Although, the gradual loss of Th1 cells was also reported during HIV-1 disease progression but relative to Th17 cells, Th1 cells were found to be more resistant to HIV-1 infection. Additionally, a significant and progressive gain in Treg cellular frequency was observed as disease progress from early to late stage of HIV-1 infection. This study also indicate that slow progressors might have an intrinsic capacity to develop strong HIV-1 specific Th17 and Th1 cell responses contrasted with a faint Treg cellular performance signifies the importance of these cellular subsets in progressive versus nonprogressive HIV-1 infection. A significant gradual loss of Th17/Treg ratio was found to be associated with disease state, plasma viral load and immune activation.

Berberine-induced pigment dispersion in Bufo melanostictus melanophores by stimulation of beta-2 adrenergic receptors.

Reduced production of melanin by decreased or the absence of melanocytes leads to various hypopigmentation disorders, and the development of melanogenetic agents for photoprotection and hypopigmentation disorders is one of the top priority areas of research. Hence, the present study was carried out to elucidate the ability of berberine, a principal active ingredient present in the roots of the herb Berberis vulgaris to stimulate pigment dispersion in the isolated skin melanophores of the toad Bufo melanostictus. In the present study, mean melanophore size index of the isolated skin melanophores of B. melanostictus was assayed after treating with various concentrations of berberine. A marked melanin dispersion response leading to skin darkening was observed in the isolated melanophores of toad in response to berberine, which was found to be mediated through beta-2 adrenergic receptors. The physiologically significant dose-related melanin dispersion effects of berberine per se were found to be completely abolished by propranolol, which is a specific beta-2 adrenergic receptor blocker. These per se melanin dispersal effects were also found to be markedly potentiated by isoprenaline, which is a specific beta-adrenoceptor agonist. The results indicate that berberine causes a tremendous, dose-dependent, physiologically significant pigment dispersing in the isolated skin melanophores of B. melanostictus.

Loss of RORγt DNA binding activity inhibits IL-17 expression in HIV-1 infected Indian individuals.

Abstract IL-17 producing CD4 T cells have recently been shown to play an important role in mucosal immunity in HIV infection. But its role in peripheral immunity and the molecular mechanism underlying its regulation during HIV-1 infection are ill defined. In this study, we report a significant negative correlation between IL-17 production in peripheral blood and HIV-1 plasma viral load (pVL). On further investigation, we observe a marked reduction in retinoid-related orphan nuclear receptor (RORγt; Th17 lineage specific transcription factor) binding at IL-17 promoter in HIV patients with high viremia (pVL>10,000 copies/mL) in contrast to relatively low viremic patients which indicate the magnitude of viral copy number on RORγt binding at IL-17 promoter. Additionally, our study highlights that FoxP3 influences IL-17 production by binding to and acting together with RORγt, consequently inhibiting RORγt binding to IL-17 promoter with growing viremia in HIV infection. Collectively, our data suggest that FoxP3 interacts with RORγt transcription factor in a viral load-dependent fashion and brings about negative impact on IL-17 production in HIV-1 infection.

5-HT receptor subtypes as key targets in mediating pigment dispersion within melanophores of teleost, Oreochromis mossambicus.

The presence of distinct class of 5-HT receptors in the melanophores of tilapia (Oreochromis mossambicus) is reported. The cellular responses to 5-HT (5-hydroxytryptamine), 5-HT(1), and 5-HT(2), agonists on isolated scale melanophores were observed with regard to pigment translocation within the cells. It was found that 5-HT exerted rapid and strong concentration dependent pigment granule dispersion within the melanophores. The threshold pharmacological dose of 5-HT that could elicit a measurable response was as low as 4.7×10(-12) M/L. Selective 5-HT(1) and 5-HT(2) agonists, sumatriptan and myristicin were investigated and resulted in dose-dependent pigment dispersion. The dispersing effects were effectively antagonized by receptor specific antagonists. It is suggested that 5-HT-induced physiological effects are mediated via distinct classes of receptors that possibly participate in modulation of pigmentary responses of the fish.

On the role of histamine receptors in regulating pigmentary responses in Oreochromis mossambicus melanophores.

PURPOSE: The present work was carried out to reveal the involvement of histamine receptors at the neuro-melanophore junction of teleost, Oreochromis mossambicus. METHODS: The isolated scale melanophores were assayed using the mean melanophore size index and their responses were recorded in presence of various concentrations of histamine along with H(1) and H(2) receptor specific agonists and antagonist and potentiator compound 48/80. RESULTS: Melanophores showed high sensitivity to histamine and its specific agonists. Histamine caused a dose-dependent pigment aggregation, whereas 2-(2-Pyridyl) ethylamine (PEA), a specific H(1)R agonist also caused aggregation in a similar manner. Conversely, amthamine, a specific H(2)R agonist resulted in pigment dispersion. The effects were antagonized by mepyramine; specific H(1)R antagonist and ranitidine a specific H(2)R antagonist. CONCLUSION: It is concluded that O. mossambicus melanophores have both H(1) and H(2) receptors which mediate melanophore aggregation and dispersion respectively. Compound 48/80 augmented the melanin-aggregating and dispersing effects of PEA and amthamine. It is suggested that the effect of histamine is directly mediated through H1 and H2 receptors, whereas H1Rs may be predominantly involved in the aggregatory responses.

HIV-1 diseases progression associated with loss of Th17 cells in subtype 'C' infection.

Th17 cells play a crucial role in host immune response. We examined the role of Th17 cells in HIV-1 'subtype-C' infection and report that HIV-1 specific Th17 cells are induced in early infection and slow progressors but are significantly reduced at late stage of infection. There was a further decline in Th17 cells in late stage subjects with gastrointestinal infections. Additionally, we observed expanded population of IL-21 (needed for Th17 population expansion) producing CD4 T cells in early and slow progressors compared to subjects with late stage infection. A significant positive correlation existed between virus specific IL-17 and IL-21 producing CD4 T cells suggesting that HIV-1 infection induces a demand for Th17 cells. A significant negative correlation between virus specific Th17 cells and HIV-1 plasma viral load (pVL) was also observed, indicating a gradual loss of Th17 cells with HIV-1 disease progression.