Soumaya Hajaji

Amoebicidal activity of α-bisabolol, the main sesquiterpene in chamomile (Matricaria recutita L.) essential oil against the trophozoite stage of Acanthamoeba castellani Neff

Acanthamoeba genus includes opportunistic pathogens which are distributed worldwide and are causative agents of a fatal encephalitis and severe keratitis in humans and other animals. Until present there are not fully effective therapeutic agents against this pathogen and thus the need to search for novel anti-amoebic compounds is urgent. Recently, essential oils of aromatic and medicinal plants have shown activity against Acanthamoeba strains. Therefore, this study was aimed to evaluate the activity of main component of chamomile essential oil (a sesquiterpene) namely α-bisabolol against the Acanthamoeba castellani Neff strain. After evaluation of the activity and toxicity of this molecule, IC50 values of 20.839 ± 2.015 for treated amoebae as well as low citotoxicty levels in a murine macrophage cell line was observed. Moreover, in order to elucidate mechanism of action of this molecule, changes in chromatin condensation levels, permeability of the plasmatic membrane, the mitochondrial membrane potential and the ATP levels in the treated amoebic strains were checked. The obtained results revealed that α-bisabolol was able to induce apoptosis, increase the permeability of the plasmatic membrane and decrease both mitochondrial and ATP levels in the treated amoebae. Therefore, and given the obtained results, α-bisabolol could be used a future therapeutic agent against Acanthamoeba infections.

Human neutrophils ROS inhibition and protective effects of Myrtus communis leaves essential oils against intestinal ischemia/reperfusion injury

The aim of the present work was to investigate the mechanism implicated in the protective effects of Myrtus communis leaves essential oils (MCEO) on human neutrophils reactive oxygen species (ROS) production. We also studied its preventive effect against intestinal ischemia reperfusion (IIR)-induced oxidative stress in rat model. Essential oils were obtained from the plant leaves by hydrodistillation and analyzed by GC-MS. Neutrophils were isolated from whole human blood using ficoll–dextran method. ROS generation and H2O2 production were measured by luminol-amplified chemiluminescence. The cytochrome c reduction assay was used for superoxide anion determination and Western blotting analysis was to determine the neutrophils myeloperoxidase (MPO) expression. Rats were divided into four groups: control (C), intestinal IR (IIR), MCEO, and MCEO plus IIR. Animals were pretreated with MCEO (50 mg kg−1) during 7 days. IIR was produced by 75 min of intestinal ischemia followed by reperfusion for 120 min. The GC-MS analysis, allowed to the identification of twenty five bioactive compounds in MCEO. In vitro, we found that MCEO inhibited ROS and H2O2 production and attenuated the neutrophils MPO expression. In vivo, the MCEO administration counteracted IIR-induced small intestine, lung and liver lipid peroxidation as well as the depletion of antioxidant enzymes activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). MCEO pretreatment also corrected IIR-induced non-enzymatic antioxidants levels depletion such as sulfhydryl groups (–SH) and reduced glutathione (GSH). More importantly, IIR was accompanied by H2O2, free iron and calcium increase while MCEO administration reversed all intracellular mediator perturbations. In conclusion, we suggest that MCEO had a potential protective role against intestinal IR injury, in part owing to its antioxidant potential and ROS scavenging activities.