Several methods have been described for the determination of phenolic compounds in animal and plant products using the Folin-Ciocalteu (FC) assay. Most of these methods describe the use of this reagent and sodium carbonate in spectrophotometric methods. The macro FC assay was compared with two micro FC assays carried out on a microplate reader. Excellent correlation was obtained among the three assays with a molar extinction coefficient of 5.228±0.187x103 M-1 cm-1. The micro assay may serve as a high throughput method for the rapid determination of polyphenols in various samples.peer-reviewe

Parkinson’s disease (PD) is a progressive neurodegenerative disorder, primarily affecting dopaminergic neurons in the substantia nigra. There is currently no cure for PD and present medications aim to alleviate clinical symptoms, thus prevention remains the ideal strategy to reduce the prevalence of this disease. The goal of this study was to investigate whether oleuropein (OLE), the major phenolic compound in olive derivatives, may prevent neuronal degeneration in a cellular dopaminergic model of PD, differentiated PC12 cells exposed to the potent parkinsonian toxin 6-hydroxydopamine (6-OHDA). We also investigated OLE’s ability to mitigate mitochondrial oxidative stress and modulate the autophagic flux. Our results obtained by measuring cytotoxicity and apoptotic events demonstrate that OLE significantly decreases neuronal death. OLE could also reduce mitochondrial production of reactive oxygen species resulting from blocking superoxide dismutase activity. Moreover, quantification of autophagic and acidic vesicles in the cytoplasm alongside expression of specific autophagic markers uncovered a regulatory role for OLE against autophagic flux impairment induced by bafilomycin A1. Altogether, our results define OLE as a neuroprotective, anti-oxidative and autophagy-regulating molecule, in a neuronal dopaminergic cellular model.

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Natural molecules are under intensive study for their potential as preventive and/or adjuvant therapies for neurodegenerative disorders such as Parkinson's disease (PD). We evaluated the neuroprotective potential of cucurbitacin E (CuE), a tetracyclic triterpenoid phytosterol extracted from the Ecballium elaterium (Cucurbitaceae), using a known cellular model of PD, NGF-differentiated PC12. In our postmitotic experimental paradigm, neuronal cells were treated with the parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP+) to provoke significant cellular damage and apoptosis or with the potent N,N-diethyldithiocarbamate (DDC) to induce superoxide (O2 •−) production, and CuE was administered prior to and during the neurotoxic treatment. We measured cellular death and reactive oxygen species to evaluate the antioxidant and antiapoptotic properties of CuE. In addition, we analyzed cellular macroautophagy, a bulk degradation process involving the lysosomal pathway. CuE showed neuroprotective effects on MPP+-induced cell death. However, CuE failed to rescue neuronal cells from oxidative stress induced by MPP+ or DDC. Microscopy and western blot data show an intriguing involvement of CuE in maintaining lysosomal distribution and decreasing autophagy flux. Altogether, these data indicate that CuE decreases neuronal death and autophagic flux in a postmitotic cellular model of PD.

Although toothpastes are considered as topical cosmetics that are not normally ingested, it is evident that they may contribute to the introduction of heavy metals and xenobiotics through buccal and gastrointestinal absorption. The purpose of this study was to determine the potential presence of metals and polyphenols in conventional, children's and herbal toothpastes. Metal analysis was conducted by using the Microwave Plasma-Atomic Emission Spectrometer and the total polyphenolic content was determined by using the Folin-Ciocalteu test. Results showed that cadmium and mercury were absent in all toothpastes while zinc and tin exhibited high values. This was because the latter two metals are incorporated as part of the ingredients. In the case of polyphenols, the highest value was obtained in one of the samples from the children's toothpaste category while the lowest value was obtained from the conventional toothpaste category. Lead and nickel were two other metals that fell outside the limits for EU and US standards. Most of these limits are usually applicable to topical cosmetic products or food products. However, these may not adequately cover oral hygiene products, such as toothpastes.

A growing number of studies have revealed that natural molecules own interesting antioxidant and anti-apoptotic properties in cell culture as well as in animal models of human diseases such as cancer, inflammatory and neurodegenerative diseases. During the past sixty years, several cucurbitacins have been isolated from a number of cucurbitaceous species, amongst others. Cucurbitacins are triterpenoid compounds originally identify as the bitter components of the Cucurbit family that demonstrated several pro-survival activities in various model of cellular decay. Specifically, Cucurbitacin E (CuE), an oxygenated tetracyclic triterpenoid, has been investigated in a wider array of bioactivities, mainly immunomodulatory. Recently, CuE has been reported to possess anti-inflammatory and anti-tumorigenic properties mediated by its action on the cellular cytoskeleton, on mitotic pathways as well as on cellular autophagy. Few studies also pinpoint the role of CuE in the nervous system as cytostatic for gliomas and neuroprotective in a model of Parkinson's diseases. This review deals with the use of CuE in various experimental models as one of the most promising therapeutic natural molecules against cancer proliferation, as an immunomudulator and for the prevention of neurodegeneration.

This review provides a comprehensive insight into the content of five heavy metals found in cosmetics and their effects at the site of application and on several organs via the dermal route of administration. Regulation of these products is very limited with little information on limits of these metals at the disposition of manufacturers. Lead and arsenic are considered to be contaminants in cosmetics whereas cadmium may be present as a coloring agent besides being a contaminant. Nickel is notorious for its association with allergic chronic dermatitis. Though mercury is rarely present in cosmetics, it has been found in significant quantities in skin lightening creams. A multi-variate meta-analysis was conducted to determine the relationships between the five metals and any possible differences between the sixteen categories of formulations used for facial and body skin care and cosmetic purposes. In general, lipsticks, eye shadows, face paints, make-up foundation and skin lightening creams exhibited a high amount of heavy metals superior to the levels of these metals in other facial and body products. The outcome of this analysis urges regulators and manufacturers to consider routine monitoring for the presence of these metals in cosmetics.

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