Chemistry

We have developed an enzyme immunoassay to measure nevirapine (NVP) in plasma and peripheral blood mononuclear cells. Anti-NVP polyclonal antibodies were raised in rabbits by using a synthetic NVP derivative coupled to keyhole limpet hemocyanin as the immunogen, and the enzyme tracer was prepared by chemically coupling the NVP derivative with acetylcholinesterase. These reagents were used to develop a sensitive competitive enzyme immunoassay performed in microtitration plates with a 100-pg ml ؊1 limit of detection and thus ϳ100 times more sensitive than previously published techniques. The plasma assay was performed directly without extraction (in this case, a 500-pg ml ؊1 limit of detection was observed) on a minimum of 30 l of plasma. This assay shows good precision and efficiency, since recovery from human plasma and cell extracts spiked with NVP ranged between 87 and 104%, with coefficients of variation of <10%. A pharmacokinetic analysis of plasma NVP was performed for seven patients infected with human immunodeficiency virus (HIV), and it gave results similar to published findings.

An operationally simple and environmentally benign protocol for the catalytic asymmetric ring opening of meso-epoxides with aromatic amines has been developed. The reactions proceeded smoothly in the presence of 1 mol % of Sc(OSO 3 C 12 H 25 ) 3 and 1.2 mol % of a chiral bipyridine ligand in water to afford -amino alcohols in high yields with excellent enantioselectivities.

The protease inhibitor lopinavir (LPV; [1S-[1R*(R*), 3R*,4R*]]-N- [4-[[(2,6-dimethylphenoxy)-acetyl]amino]-3-hydroxy-5-phenyl-1-(phenylmethyl) pentyl] tetrahydro-a-(1-methylethyl)-2-oxo-1(2H)-pyrimide acetamide) is widely used in antihuman immunodeficiency virus (HIV) therapy. Knowledge of the plasma and intracellular concentrations of the drug would be useful for a better understanding of LPV action and for therapeutic monitoring. The aim of this study was to develop a sensitive and specific immunoassay for LPV in plasma and cells. Anti-LPV polyclonal antibodies were raised in rabbits using a synthetic LPV derivative coupled to keyhole limpet hemocyanin (KLH) as immunogen. The enzyme tracer was prepared by chemically coupling the LPV derivative with acetylcholinesterase. These reagents were used to develop a competitive enzyme immunoassay (EIA) performed in microtitration plates. The assay was performed on a minimum of 50 Al of plasma or 2Â10 6 cells. It showed good precision and efficiency inasmuch as recovery from human plasma and cell extracts spiked with LPV ranged between 87% and 104%, with coefficients of variation of less than 10%. The limit of detection (LOD) was 100 pg/ml, i.e., a value at least 10 times lower than those currently achieved using previously described techniques. Cross-validation with high-performance liquid chromatography (HPLC) revealed a good correlation between methods (r 2 =0.96). Intracellular 0022-1759/$ -see front matter D

Cancer stem cells (CSCs) are a specific subset of cancer cells that sustain tumor growth and dissemination. They might represent a significant treatment target to reduce malignant progression and prevent tumor recurrence. In solid tumors, several hierarchically organized CSC clones coexist, even within a single tumor. Among them, CSCs displaying an embryonic stem cell 'stemness' signature, based on the expression of Oct-4, Nanog and Sox2, are present in distinct high-grade tumor types associated with poor prognosis. We previously designed a model to isolate pure populations of these CSCs from distinct solid tumors and used it to screen for molecules showing selective toxicity for this type of CSC. Here we show that human immunodeficiency virus (HIV)-protease inhibitors (HIV-PIs) specifically target CSCs expressing an embryonic signature derived from tumors with distinct origins. They reduced proliferation in a dose-dependent manner with a higher specificity as compared with the total population of cancer cells and/or healthy stem cells, and they were efficient in inducing cell death. Lopinavir was the most effective HIV-PI among those tested. It reduced self-renewal and induced apoptosis of CSCs, subsequently impairing in vivo CSC-induced allograft formation. Two key pharmacophores in the LPV structure were also identified. They are responsible for the specificity of CSC targeting and also for the overall antitumoral activity. These results contribute to the identification of molecules presenting selective toxicity for CSCs expressing an embryonic stemness signature. This paves the way to promising therapeutic opportunities for patients suffering from solid cancer tumors of poor prognosis.

To assess the impact on cord blood (CB) thyroglobulin (Tg) of early iodine supplementation during pregnancy. A total of 111 healthy pregnant women with normal thyroid function were included in a prospective randomized study and divided into two groups with (150 μg/day) or without iodine supplementation started during the first trimester. Maternal smoking was assessed qualitatively by self-reported statements and quantitatively by cotininuria. Exhaustive thyroid tests were performed at delivery in the mother and in CB. Third-trimester ioduria documented compliance with iodine supplementation (160 vs. 76 μg/l in controls). CB Tg was not different between the iodine and control groups (median 77 vs. 79.5 ng/ml, respectively) and did not correlate with maternal ioduria. CB Tg was higher in newborns from smoking mothers (114 vs. 64.7 ng/ml) and correlated with self-reported smoking status more than with maternal cotininuria. Nonsmokers had no difference in CB Tg whether they took iodine supplementation or not, as opposed to smokers, who tended to benefit from supplementation. Iodine supplementation does not significantly impact CB Tg in healthy nonsmoker pregnant women selected for normal thyroid function, as opposed to maternal smoking. CB Tg appears to be a marker of in utero tobacco exposure. In areas of mild iodine deficiency, iodine supplementation could especially benefit the fetuses of smokers.

Study of plasma and intracellular concentrations of atazanavir, lopinavir, nevirapine, and efavirenz was conducted on 48 patients under short cycles of antiretroviral therapy. Intracellular concentrations (IC) were still measurable for all drugs after 85 h or 110 h drug intake despite the absence of drug in plasma for atazanavir and lopinavir. A linear relationship between plasma and intracellular efavirenz was observed. Further studies to fully understand the impact of IC in the intermittent antiviral treatment are required.

With the public's growing interest in skin whitening, lightening ingredients only used under dermatological supervision until recently, are more and more frequently incorporated into cosmetic formulas. The active agents that lighten skin tone are either natural or synthetic substances, and may act at various levels of melanogenesis. They are used to treat various skin pigmentation disorders or simply to obtain a lighter skin tone as whiter skin may be synonymous of wealth, health, youth, and/or beauty in different cultures. However, recent studies demonstrated the adverse effects of some of these ingredients, leading to their interdiction or restricted use under the European Directive and several other international regulations. After an overview of skin whitening practices and the associated risks, this article provides insight into the mechanisms involved in melanin synthesis and the biological assays available to attest the lightening activity of individual ingredients. The legislation dealing with the use of skin lighteners is then discussed. As traditional depigmenting agents such as hydroquinone and corticosteroids are of safety concern, the potential of natural extracts has been investigated more and more; finally, a synthesis of three years of research in our laboratory for such plant extracts will be given.

Background: Vetiver is a key ingredient for the perfume industry nowadays. However, with the constant and rapid changes of personal tastes, this appeal could vanish and this sector could decline quite quickly. New dissemination paths need to be found to tap this valuable resource. Methods: In this way, its potential use in cosmetics either as an active ingredient per se (with cosmeceutical significance or presenting antimicrobial activity) has hence been explored in vitro. Results: In this contribution, we demonstrated that vetiver essential oil displays no particularly significant and innovative cosmetic potential value in formulations apart from its scent already largely exploited. However, evaluated against twenty bacterial strains and two Candida species using the in vitro microbroth dilution method, vetiver oil demonstrated notably some outstanding activities against Gram-positive strains and against one Candida glabrata strain. Conclusions: Based on these findings, vetiver ess...

Maintenance of the adipose tissue requires a proper balance between self-renewal and differentiation of adipose progenitors (AP). Any deregulation leads either to fat overexpansion and obesity or fat loss and consequent lipodystrophies. Depending on the fat pad location, APs and adipocytes are heterogeneous. However, information on the pharmacological sensitivity of distinct APs to drugs known to alter the function of adipose tissue, especially HIV protease inhibitors (PIs) is scant. Here we show that PIs decreased proliferation and clonal expansion of APs, modifying their self-renewal potential. Lopinavir was the most potent PI tested. Decrease in self-renewal was accompanied by a reduced expression of the immediate early response gene IER3, a gene associated with tissue expansion. It was more pronounced in chin-derived APs than in knee-derived APs. Furthermore, lopinavir lowered the activin A-induced ERK1/2 phosphorylation. Expressions of the transcription factor EGR1 and its targets, including INHBA were subsequently altered. Therefore, activin A secretion was reduced leading to a dramatic impairment of APs self-renewal sustained by the activin A autocrine loop. All together, these observations highlight the activin A autocrine loop as a crucial effector to maintain APs self-renewal. Targeting this pathway by HIV-PIs may participate in the induction of unwanted side effects. The adipose tissue (AT) represents the most adaptable tissue of an organism. It exists as functionally different depots that display opposite functions to fulfill the energy demand. In response to elevated calorie intake, white adipose tissue expansion allows energy storage as triglycerides. It represents the most abundant adipose tissue in adult humans. In contrast, brown adipose tissue is a key thermogenic organ able to produce heat from nutriments by uncoupling respiration from ATP synthesis. It surrounds the deepest organs 1 and represents the lesser part of adipose tissue. White AT is present all over the human body and is composed of distinct depots that are heterogeneous in terms of cellular composition, proliferation and differentiation 2, 3. The adipose progenitor (AP) pool hosted within the adipose tissues is crucial for AT development and to form new fat cells upon appropriated stimulus that induce adipocyte differentiation. This process is essential because like most mature and specialized healthy cells, adipocytes are generated through differentiation of progenitor cells as they do not divide in vivo. Thus, the AP pool is directly correlated with adipose tissue development and linked to fat mass 4. Our lab has recently shown that the AP pools are derived from distinct embryonic origins. In rodents, while the intra-abdominal depots originate from mesoderm, those from the face display a neuro-ectodermal origin 5. This feature is also encountered in humans since APs from chin and knee do not express the same homeobox genes (HOX) code. Indeed, they produce adipocytes displaying different phenotypes: upon adipose differentiation, chin APs give rise preferentially to cells with brown/brite adipocytes features while knee APs are prone to generate white adipocytes 6. All these observations suggest that the different fat depots are not equal either in terms of structures but also for physiological and metabolic functions. As AP cells need to perpetuate all life long, this pool is located in niches that maintain their intrinsic properties and control the self-renewal throughout adult life. Many factors present in the adipose tissue microenvironment are involved in a proper regulation of the balance between self-renewal and differentiation of these cells, including activin A which maintains the AP pool through autocrine and paracrine mechanisms 7, 8. In addition, we recently identified

Skin whitening agents occupy an important part of the dermo-cosmetic market nowadays. They are used to treat various skin pigmentation disorders, or simply to obtain a lighter skin tone. The use of traditional skin bleachers (e.g., hydroquinone, corticoids) is now strictly regulated due to their side effects. When considering this and the growing consumers' interest for more natural ingredients, plant extracts can be seen as safe and natural alternatives. In this perspective, in vitro bioassays were undertaken to assess cosmetic potential of Reseda luteola, and particularly its promising whitening activities. A bioguided purification procedure employing centrifugal partition chromatography, Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-HRMS) and NMR was developed to isolate and identify the whitening agents (i.e., luteolin and apigenin) from aerial parts of R. luteola. UPLC-HRMS also enabled the characterization of acetylated luteolin-and apigenin-O-glycosides, which occurrence is reported for the first time in R. luteola.

Consumers pay more and more attention not just to the safety and health aspects of ingredients entering their cosmetics' formulations, but also to their potency, origin, processing, ethical value and environmental footprint. Sustainability of the supply chain, preservation of biodiversity, as well as greener extraction techniques are hence very popular with consumers. Consumers are primarily concerned by the efficacy of the cosmetic products they use and continuously scrutinize product labels, so marketing arguments need to be based on rigorous testing and reliable results to support claims (anti-age, anti-pollution, etc.) displayed on the product's packaging. As a result, the increasing demand for natural ingredients with assessed bioactivities has profoundly modified the strategies adopted by cosmetic professionals to innovate in terms of actives. Sourcing and developing new natural cosmetic actives is a long-term procedure that is thoroughly described in the present paper, via the example of the design of both liquid and solid ingredients based on Quercus pubescens Willd. leaves extract, for which anti-age properties were assessed by a combination of in vitro assays.

The ethical and ecological concerns of today’s consumers looking for both sustainable and efficient ingredients in finished products, put a lot of pressure on the cosmetic market actors who are being driven to profoundly modify the strategies adopted to innovate in terms of actives while notably being urged to switch from petroleum- to plant-based ingredients. To produce such natural cosmetic ingredients, agri-food by-products are advocated as raw material due to their reduced carbon footprint as they actively contribute to the worldwide improvement of waste management. The process to transform plant waste materials into such powerful and objectified “green” cosmetic actives in compliance with circular economy principles is a long-term integrated process. Such a development is thoroughly exemplified in the present paper through the description of the design of liquid anti-age ingredients based on Ribes nigrum L. extract. This was obtained by maceration of blackcurrant pomace. and th...

Melanoma patients harboring the BRAFV600E mutation are treated with vemurafenib. Almost all of them ultimately acquire resistance, leading to disease progression. Here, we find that a small molecule from a marine sponge, panicein A hydroquinone (PAH), overcomes resistance of BRAFV600E melanoma cells to vemurafenib, leading to tumor elimination in corresponding human xenograft models in mice. We report the synthesis of PAH and demonstrate that this compound inhibits the drug efflux activity of the Hedgehog receptor, Patched. Our SAR study allowed identifying a key pharmacophore responsible for this activity. We showed that Patched is strongly expressed in metastatic samples from a cohort of melanoma patients and is correlated with decreased overall survival. Patched is a multidrug transporter that uses the proton motive force to efflux drugs. This makes its function specific to cancer cells, thereby avoiding toxicity issues that are commonly observed with inhibitors of ABC multidrug ...