15 research outputs found

    Experimental Determination and Correlation of Artemisinin's Solubility in Supercritical Carbon Dioxide

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    The measurement and correlation of the experimental solubility of the antimalarial artemisinin (Artemisia annua L.) in supercritical carbon dioxide is reported. Results were obtained using a static analytical method at 308.2, 318.2, and 328.2 K, and in a pressure range from 10.0 up to 25.0 MPa. Solubility experimental data were correlated with three density-based models (Chrastil, Bartle, and Méndez-Santiago−Teja models) and with two cubic equation of state (EOS) models, namely, the Peng−Robinson EOS and the Soave−Redlich−Kwong EOS, together with the conventional van der Waals mixing and combining rules. Good correlation results were obtained between the calculated and the experimental solubility to all fitted models. Results clearly show the feasibility of processing this antimalarial drug using supercritical fluid technologies and processes

    The selective PAC1 receptor agonist maxadilan inhibits neurogenic vasodilation and edema formation in the mouse skin

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    We have earlier shown that PACAP-38 decreases neurogenic inflammation. However, there were no data on its receptorial mechanism and the involvement of its PAC1 and VPAC1/2 receptors (PAC1R, VPAC1/2R) in this inhibitory effect. Neurogenic inflammation in the mouse ear was induced by topical application of the Transient Receptor Potential Ankyrin 1 (TRPA1) receptor activator mustard oil (MO). Consequent neurogenic edema, vasodilation and plasma leakage were assessed by measuring ear thickness with engineer's micrometer, detecting tissue perfusion by laser Doppler scanning and Evans blue or indocyanine green extravasation by intravital videomicroscopy or fluorescence imaging, respectively. Myeloperoxidase activity, an indicator of neutrophil infiltration, was measured from the ear homogenates with spectrophotometry. The selective PAC1R agonist maxadilan, the VPAC1/2R agonist vasoactive intestinal polypeptide (VIP) or the vehicle were administered i.p. 15 min before MO. Substance P (SP) concentration of the ear was assessed by radioimmunoassay. Maxadilan significantly diminished MO-induced neurogenic edema, increase of vascular permeability and vasodilation. These inhibitory effects of maxadilan may be partially due to the decreased substance P (SP) levels. In contrast, inhibitory effect of VIP on ear swelling was moderate, without any effect on MO-induced plasma leakage or SP release, however, activation of VPAC1/2R inhibited the increased microcirculation caused by the early arteriolar vasodilation. Neither the PAC1R, nor the VPAC1/2R agonist influenced the MO-evoked increase in tissue myeloperoxidase activity. These results clearly show that PAC1R activation inhibits acute neurogenic arterial vasodilation and plasma protein leakage from the venules, while VPAC1/2R stimulation is only involved in the attenuation of vasodilation
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