Elucidation of mechanisms underlying the protective effects of olive leaf extract against lead-induced neurotoxicity in Wistar rats.

Recently, we identified that olive leaf extract (OLE) prevents lead (Pb)-induced abnormalities in behavior and neurotransmitters production in chronic Pb exposure in rats. The aim of the present study was to provide additional evidence that OLE acts as an anti-apoptotic, anti-inflammatory, and antioxidant mediator in Pb exposed rats. 4-weeks old Wistar rats were exposed or not to 250 mg/l Pb for 13-weeks and then exposed to tap water containing or not 0.1% OLE for additional 2-weeks. Atomic absorption spectrophotometry showed significantly elevated Pb levels in the hippocampus and serum and reaches 5 and 42 µg/mg tissue, respectively. In the hippocampus, the examination of markers of apoptosis and inflammation revealed an increase in caspase-3 activity and DNA fragmentation as well as tumor necrosis factor alpha, interleukin-1 beta and prostaglandin E2 in Pb-exposed rats. In addition, our findings showed that Pb induced 4-hydroxynonenal production and inhibited antioxidant-related enzyme activity, such as glutathione-S-transferase as wells as energy metabolism-related enzyme activity, such as NADP-isocitrate dehydrogenase and glucose transporter. Upon examination of signaling pathways involved in apoptosis process, we found that Pb induced p38 mitogen activated protein kinase (MAPK) and Akt phosphorylation, but in contrast, inhibited that of ERK(1/2). Interestingly, OLE administration diminished tissue Pb deposition and prevented all Pb effects. In the frontal cortex, our data also showed that OLE-abolished Pb-induced caspase-3 activity and DNA fragmentation. Collectively, these data support the use of OLE by traditional medicine to counter Pb neurotoxicity.

Role of wormwood (Artemisia absinthium) extract on oxidative stress in ameliorating lead induced haematotoxicity.

Effects of ROS generation have been postulated to be major contributors to lead-exposure related disease. The aim of the study was to investigate the effect of aqueous extract of wormwood (Artemisia absinthium) on oxidative stress in rats protractedly exposed to lead. Aqueous extract of wormwood plant was administered orally (200 mg x kg(-1) body weight). Plasma vitamin C, E and non-protein thiol concentrations, red blood cells (RBC) thiobarbituric acid reactive substances, reduced glutathione levels and haemolysis test were evaluated. In addition, RBC antioxidant enzymes activities such as superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase were also estimated. After 11-weeks, significant decreases of plasma vitamin C, E, non protein-thiol (NP-SH) and RBC-reduced glutathione levels were observed in Pb compared to control group (-32.9%, -57.1%, -53.1%, -33.9%, respectively); superoxide dismutase, glutathione peroxidase, uric aminolevulinic acid and haemolysis test significantly increased in Pb compared to control group (+64.3%, +40.3%, +145%, +44.3%, respectively). In our investigation, after 4-weeks of treatment all treated groups did not show any difference compared to the control group, except for glutathione peroxidase and RBC-superoxide dismutase activity (-15.7% and +16.4%, respectively). The findings of this study suggest that wormwood (Artemisia absinthium) extract restored the enzymes activities perturbed by exposure to lead, and had a protective role against lipid peroxidation.