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International audience; The essential oil component α-pinene has multiple biological activities. However, its application is limited owing to its volatility, low aqueous solubility, and chemical instability. For the aim of improving its physicochemical properties, α-pinene was encapsulated in conventional liposomes (CLs) and drug-in-cyclodextrin-in-liposomes (DCLs). Hydroxypropyl-β-cyclodextrin/α-pinene (HP-β-CD/α-pinene) inclusion complexes were prepared in aqueous solution, and the optimal solubilization of α-pinene occurred at HP-β-CD:α-pinene molar ratio of 7.5:1. The ethanol-injection method was applied to produce different formulations using saturated (Phospholipon 90H) or unsaturated (Lipoid S100) phospholipids in combination with cholesterol. The size, the phospholipid and cholesterol incorporation rates, the encapsulation efficiency (EE), and the loading rate (LR) of α-pinene were determined, and the storage stability of liposomes was assessed. The results showed that α-pinene was efficiently entrapped in CLs and DCLs with high EE values. Moreover, Lipoid S100 CLs displayed the highest LR (22.9 ± 2.2%) of α-pinene compared to the other formulations. Both carrier systems HP-β-CD/α-pinene inclusion complex and Lipoid S100 CLs presented a gradual release of α-pinene. Furthermore, the DPPH radical scavenging activity of α-pinene was maintained upon encapsulation in Lipoid S100 CLs. Finally, it was found that all formulations were stable after three months of storage at 4 °C.

Background: Oximes are used in addition to atropine to treat organophosphate poisoning. However, the efficiency of oximes is still a matter of debate. In vitro experiments suggested than new oximes are more potent than the commercial oximes. However, the antidotal activity of new oximes has not been assessed in vivo. Methods: The aim of this work was to assess the safety and efficiency of new oximes compared to pralidoxime in a rat model of diethyl paraoxon-induced non-lethal respiratory toxicity. Results: Safety study of oximes showed no adverse effects on ventilation in rats. KO-33, KO-48, KO-74 oximes did not exhibit significant antidotal effect in vivo. In contrast, KO-27 and BI-6 showed evidence of antidotal activity by normalization of respiratory frequency and respiratory times. KO-27 became inefficient only during the last 30 min of the study. In contrast, pralidoxime demonstrated to be inefficient at 30 min post injection. Inversely, the antidotal activity of BI-6 occurred lately, within the last 90 min post injection. Conclusion: This study showed respiratory safety of new oximes. Regarding, the efficiency, KO-27 revealed to be a rapid acting antidote toward diethylparaoxon-induced respiratory toxicity, meanwhile BI-6 was a late-acting antidote. Simultaneous administration of these two oximes might result in a complete and prolonged antidotal efficiency.

Oleanolic acid (OA) is a triterpenoid, widely found in plants and possesses antitumor activity in many cancer lines. However, cancer cells develop multidrug resistance (mdr) hindering the effect of anticancer drugs. P-glycoprotein (P-gp) is a major cause of mdr. Therefore, the cytotoxic effect of OA was evaluated on human breast cancer MDA-MB-231 and human liver cancer HepG2 with absence and presence of P-gp, respectively. OA reduced MDA-MB-231 viability in a dose dependent manner, whereas no remarkable effect was observed on HepG2 in the same range of concentrations (1–60 μM). Moreover, cytotoxicity studies were conducted in the presence of verapamil (20 mg/L), a P-gp inhibitor. OA exhibited the same effect on MDA-MB-231 in the absence and presence of verapamil. However, the cytotoxicity was greatly enhanced for HepG2 cells in the presence of verapamil (cell viability dropped from 63.7% to 25% after 72 h at 60 μM). The results were then confirmed in vivo on zebrafish embryos. Increased mortality and malformations were observed in verapamil pretreated group between 5 and 15 μM of OA compared to control; also, all embryos died at 20 μΜ OA and above. These results demonstrate that inhibiting P-gp enhances the chemotherapeutic activity of OA.