645 research outputs found

    Modulation of the UVA activation of haem oxygenase, collagenase and cyclooxygenase gene expression by epigallocatechin in human skin cells

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    AbstractWe have investigated the modifying effects of epigallocatechin, a major polyphenolic constituent of green tea, on ultraviolet-A-activated gene expression in human fibroblasts and keratinocytes using the stress responsive enzymes: haem oxygenase-1, interstitial collagenase and cyclooxygenase-2. Although epigallocatechin strongly reduced ultraviolet-A-induced haem oxygenase-1 activation in skin-derived fibroblasts, the same compound activated collagenase and cyclooxygenase expression. In a keratinocyte cell line, ultraviolet-A-mediated haem oxygenase-1 over-expression was low and epigallocatechin failed to modulate it further. In contrast to the results with fibroblasts, ultraviolet-A activation of cyclooxygenase in keratinocytes was reduced by epigallocatechin. The results indicate that the effect of this green tea polyphenol on cellular stress responses is complex and may involve direct effects on signal transduction as well as changes that may be associated with its antioxidant activity

    Multivariate Affine Fractal Interpolation

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    Fractal interpolation functions capture the irregularity of some data very effectively in comparison with the classical interpolants. They yield a new technique for fitting experimental data sampled from real world signals, which are usually difficult to represent using the classical approaches. The affine fractal interpolants constitute a generalization of the broken line interpolation, which appears as a particular case of the linear self-affine functions for specific values of the scale parameters. We study the p convergence of this type of interpolants for 1 = p < 8 extending in this way the results available in the literature. In the second part, the affine approximants are defined in higher dimensions via product of interpolation spaces, considering rectangular grids in the product intervals. The associate operator of projection is considered. Some properties of the new functions are established and the aforementioned operator on the space of continuousfunctions defined on a multidimensional compact rectangle is studied

    Genetic divergence and its implication in breeding of desired plant type in coriander -Coriandrum sativum L.-

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    Seventy germplasm lines of coriander (Coriandrum sativum L.) of diverse eco-geographical origin were undertaken in present investigation to determine the genetic divergence following multivariate and canonical analysis for seed yield and its 9 component traits. The 70 genotypes were grouped into 9 clusters depending upon the genetic architecture of genotypes and characters uniformity and confirmed by canonical analysis. Seventy percent of total genotypes (49/70) were grouped in 4 clusters (V, VI, VIII and IX), while apparent diversity was noticed for 30 percent genotypes (21/70) that diverged into 5 clusters (I, II, III, FV, and VII). The maximum inter cluster distance was between I and IV (96.20) followed by III and IV (91.13) and I and VII (87.15). The cluster VI was very unique having genotypes of high mean values for most of the component traits. The cluster VII had highest seeds/umbel (35.3 ± 2.24), and leaves/plant (12.93 ± 0.55), earliest flowering (65.05 ± 1.30) and moderately high mean values for other characters. Considering high mean and inter cluster distance breeding plan has been discussed to select desirable plant types

    Keratinocyte Carcinoma and Photoprevention:The Protective Actions of Repurposed Pharmaceuticals, Phytochemicals and Vitamins

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    SIMPLE SUMMARY: Keratinocyte carcinoma is the most common type of cancer. Sun exposure and ultraviolet radiation are significant contributors to the development of carcinogenesis, mediated by DNA damage, increased oxidative stress, inflammation, immunosuppression and dysregulated signal transduction. Photoprevention involves using different compounds to delay or prevent ultraviolet radiation-induced skin cancer. In this review, we look at new avenues for systemic photoprevention that are based on pharmaceuticals, plant-derived phytochemicals and vitamins. We also investigate the mechanisms underlying these strategies for preventing the onset of carcinogenesis. ABSTRACT: Ultraviolet radiation (UVR) arising from sun exposure represents a major risk factor in the development of keratinocyte carcinomas (KCs). UVR exposure induces dysregulated signal transduction, oxidative stress, inflammation, immunosuppression and DNA damage, all of which promote the induction and development of photocarcinogenesis. Because the incidence of KCs is increasing, better prevention strategies are necessary. In the concept of photoprevention, protective compounds are administered either topically or systemically to prevent the effects of UVR and the development of skin cancer. In this review, we provide descriptions of the pathways underlying photocarcinogenesis and an overview of selected photoprotective compounds, such as repurposed pharmaceuticals, plant-derived phytochemicals and vitamins. We discuss the protective potential of these compounds and their effects in pre-clinical and human trials, summarising the mechanisms of action involved in preventing photocarcinogenesis

    Site-directed mutagenesis of Saccharomyces cerevisiae β-tubulin: interaction between residue 167 and benzimidazole compounds

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    AbstractBenzimidazoles are widely used as anthelmintic agents and systemic fungicides. In susceptible organisms, benzimidazoles bind to β-tubulin and block microtubule polymerization. To further characterize this interaction, site-directed mutagenesis followed by gene replacement was used to change Saccharomyces cerevisiae β-tubulin residue Phe-167 to Tyr. Consistent with previous studies, this mutation resulted in at least 3–4-fold decreased sensitivity to the benzimidazole derivatives carbendazim and nocodazole. The Tyr-167 mutant was cold sensitive, implying a direct effect on benzimidazole binding rather than a nonspecific increase in microtubule stability. Surprisingly, the mutant had 8-fold increased sensitivity to the derivative benomyl, which is structurally identical to carbendazim except at position 1. This suggests that residue 167 interacts with benzimidazoles in the vicinity of the 1-position
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