Phenolic composition and biological activities of Juniperus drupacea Labill. berries from Turkey.

The present study was designed to define the phenolic profile and the biological potential of berries methanol extract of Juniperus drupacea Labill. from Turkey. The total phenolic content (Folin-Ciocalteau assay) was 48.06±0.99mgGAE/g extract. The HPLC-DAD-ESI-MS analysis allowed the determination of the complete phenolic profile of J. drupacea berries. Phenolic acids represented more than 60% of the total phenolics, and tyrosol was the major one (1324±0.64µg/g extract); within the flavonoids amentoflavone was detected as the main constituent (927±0.35µg/g extract). The extract exhibited good antioxidant properties, as determined by different in vitro models: DPPH test (IC(50) 0.38±0.02mg/mL), reducing power (12.63±0.14ASE/mL), Fe(2+) chelating ability (IC(50) 2.26±0.06mg/mL), and TBA test (IC(50) 2.47±1.13µg/mL). Cytotoxicity against Artemia salina was highlighted (LC(50) 489.47±27.8µg/mL), and a significant decrease (p⩽0.05; p⩽0.01) in HepG2 cells viability was observed at the higher concentrations (5-10µg/mL). The extract displayed good antibacterial activity towards Gram-positive bacteria and in particular Staphylococcus aureus was the most susceptible strain (MIC 78.12µg/mL).

Exposure of human skin to benzo[a]pyrene: role of CYP1A1 and aryl hydrocarbon receptor in oxidative stress generation.

Exposure to benzo[a]pyrene (BaP) can induce inflammatory skin diseases and skin cancer, which are both associated to oxidative stress. BaP is known to bind with high specificity to the aryl hydrocarbon receptor (AhR), modifying the expression of CYP1A1, involved both in cancer and inflammation. While the current knowledge is based on murine skin and cell culture data, in this study human healthy skin has been treated with 5muM BaP in conditions simulating occupational and environmental exposure. AhR and CYP1A1 expression was evaluated by Western blotting, which revealed their presence even in control untreated skin; both enzyme and receptor increased more than twofold after exposure to BaP. AhR expression level was lower than CYP1A1 in basal conditions and following induction. Oxidative stress was evaluated in terms of MTT reduction, protein peroxidation and reactive oxygen species (ROS) formation. A significant increase in ROS and carbonyl compound production, as well as reduced tissue viability have been determined by BaP. The results of this experiment indicate that BaP, an AhR agonist, can significantly increase receptor and CYP1A1 expression and induce oxidative stress in human skin, confirming the involvement of this pathway in the pathogenesis of tissue damage due to polycyclic aromatic hydrocarbons.

Erucin, a new promising cancer chemopreventive agent from rocket salads, shows anti-proliferative activity on human lung carcinoma A549 cells.

Erucin (ER) is a dietary isothiocyanate present in cruciferous vegetables, such as rocket salads (Erucasativa Mill., Diplotaxis sp.), that has been recently considered a promising cancer chemopreventive phytochemical. Biological activity of ER was investigated on human lung adenocarcinoma A549 cells, analyzing its effects on molecular pathways involved in apoptosis and cell cycle arrest, such as PARP-1 cleavage, p53 and p21 protein expression. Our results show that ER affects the A549 cell proliferation, enhancing significantly p53 and p21 protein expression in a dose-dependent manner (p<0.001). PARP-1 cleavage occurs only after exposure to high concentrations of ER (50 microM), in accordance to previous studies showing similar bioactivity of other isothiocyanates (ITCs). Our study reports for the first time that the induction of p53, p21 and PARP-1 cleavage may participate in the anti-proliferative activity of ER in human lung adenocarcinoma A549 cells. Comparison of data with those obtained with the isothiocyanate sulforaphane (SF), structurally related to ER, underlines the strong relationship between structural analogy of ITCs and their biological activity. The ability of dietary compounds to modulate molecular mechanisms that affect cancer cell proliferation is certainly a key point of the cancer prevention potential by functional foods.

Genotoxicity of imidacloprid in relation to metabolic activation and composition of the commercial product.

Imidacloprid is a neonicotinoid insecticide combining excellent efficiency against parasites with low toxicity for mammals. Commercially, it is co-formulated with dimethyl sulfoxide, methylpyrrolidone, propylene carbonate and mineral oil, which can modify its bioavailability and toxicological profile for humans following occupational exposure. A combined in vitro approach employing the comet assay and the micronucleus test was used to assess the genotoxicity of imidacloprid in relation to formulation, metabolic activation and exposure level. Human peripheral blood lymphocytes from unexposed healthy volunteers were treated with imidacloprid (0.2, 2 and 20 µM) and with equimolar concentrations of a commercial product, with and without addition of S9 fraction. Imidacloprid significantly increased the comet score and the frequency of micronuclei only at the highest concentration tested. DNA damage was slightly more severe with the commercial product, and was increased, though not significantly, by metabolic activation. Formation of reactive oxygen species (ROS) does not seem to be involved as a mechanism of genotoxicity, but this result may be explained by the insufficient sensitivity of the 2',7'-dichlorofluorescein diacetate assay at the test concentrations of imidacloprid. These results suggest that at concentrations<20 µM imidacloprid is not genotoxic to human lymphocytes in vitro. Nonetheless, the presence of co-formulants in the commercial product and occupational exposure, along with poor safety procedures, may present an increased risk for DNA fragmentation and chromosomal aberrations.