Physical and chemical characterizations of a reference e-cigarette used in animal testing.

A minimal necessary condition for preclinical studies to contribute to risk assessments of e-cigarettes (ECs) is the ability to expose laboratory animals to an appropriate dosage of aerosols. In this study, we examined the fulfilment of this essential consistency condition for the ECX-Joyetech E-Vic Mini (ECX), a piece of computerized exposure equipment manufactured by SCIREQ, which has been employed by numerous in vivo testing. We began by calibrating the customary Evic VTC mini device mod and the 4 coils available, reproducing in the laboratory the operation of the ECX in the power-control and temperature-control modes, using puffing parameters recommended by its documentation. We then conducted the following tests for each coil: (1) verifying whether the generated aerosols satisfy an optimal operational regime, free from overheating, as determined by a linear relation between the mass of vaporized e-liquid vs. supplied power and (2) obtaining the mean yields of aldehydes for each of the tested power settings and coils. The results of these tests show that, under the main conditions used in in vivo testing, the ECX equipment fails to comply with these consistency requirements, especially for coils with low subohm resistance, a shortcoming that can be corrected by applying much larger airflows for these coils. Therefore, the outcomes of preclinical studies using the ECX equipment should be examined with great scepticism and subjected to further testing.

Screening and Evaluation of Dermo-Cosmetic Activities of the Invasive Plant Species Polygonum cuspidatum.

Polygonum cuspidatum (P. cuspidatum) is among the world's most problematic invasive plant species with negative ecological, socio-economic and security consequences. Management operations in areas invaded systematically generate a large quantity of plant waste, most often without outlets. Using this plant material could constitute a new alternative treatment for sustainable management. P. cuspidatum is well known to have numerous biological properties, containing notably stilbenes, quinones, flavonoids and phenolic acids. The present work proposes a reliable strategy using powerful techniques for the screening and the evaluation of the dermo-cosmetic potential of its aerial parts (AP) and root parts (RP). To the best of our knowledge, only antioxidant and anti-tyrosinase activities were previously evaluated on P. cuspidatum among the targets studied (superoxide dismutase, hyaluronidase, elastase, collagenase and tyrosinase). The results revealed strong antioxidant and anti-collagenase activities, moderate anti-hyaluronidase activity, while weak anti-elastase and anti-tyrosinase activities were observed for ethanolic extracts. Different standards selected and screened on the same targets made it possible to correlate the observed residual activities of produced extracts of P. cuspidatum from Savoie Mont Blanc and their chemical compositions. A structure-activity study was thus conducted on main molecular families, widely represented in the genus Polygonum.