Induction of hyperadrenergic activity was experimentally achieved in urethane-anesthetized rats using epinephrine (adrenaline). Acute administration of epinephrine (100 microg/kg) for 2 hours induced several cardiac disorders and vasomotor dysfunction. Pretreatment with natural wild honey (5 g/kg) for 1 hour prior to the injection with epinephrine (100 mug/kg) protected the anesthetized normal rats from the incidence of epinephrine-induced cardiac disorders and vasomotor dysfunction. Moreover, posttreatment with natural wild honey (5 g/kg) following the injection with epinephrine (100 microg/kg) for 1 hour showed several ameliorative outcomes to the electrocardiographic parameters and vasomotor dysfunction of anesthetized stressed rats. Furthermore, natural wild honey preserved the positive inotropic effect of epinephrine in both cases. Also, the total antioxidant capacity (AOC) of natural wild honey was found to be very pronounced. Levels of both reduced glutathione and ascorbic acid (vitamin C) were considered relatively high in natural wild honey. Activity of superoxide dismutase (SOD) was also high, whereas catalase activity was relatively low, especially when compared to the value of SOD activity. It would appear from the results of the present study that natural wild honey may exert its cardioprotective and therapeutic effects against epinephrine-induced cardiac disorders and vasomotor dysfunction directly, via its very pronounced total AOC and its great wealth of both enzymatic and nonenzymatic antioxidants involved in cardiovascular defense mechanisms, besides its substantial quantities of mineral elements such as magnesium, sodium, and chlorine, and/or indirectly, via the enhancement of the endothelium-derived relaxing factor nitric oxide release through the influence of ascorbic acid (vitamin C).

The present data on the extracts of C. procera indicate a direct action on the myocardium, stimulatory effect on smooth muscle motility, and relaxant action on skeletal muscle contraction. Chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.

No abstract

Passive sampling could provide the solution to problems associated with costly and time consuming sampling programmes and biomonitoring. Mussels (Mytilus edulis) and Chemcatcher passive sampler were simultaneously analyzed for sequestered pesticides and polychlorinated biphenyls (PCBs) by gas chromatography with mass spectrometry (GC/MSD). The Chemcatcher passive sampler based on a solid phase extraction disc with two types of diffusion-limiting membranes (polyethelene and polysulphone), were also compared. Diuron, atrazine, irgarol and lindane were accumulated in the polysulphone passive sampler in greater concentration than in the mussels or in the other passive samplers with polyethelene limiting-membrane. Mussels can accumulate in their tissue high concentration of non polar compounds such as PCB 52, dieldren and PCB 153; more than the passive sampler with polysulphone membrane. The device with polyethelene limiting membrane has high affinity capacity to concentrate high amount of phenenthrene, dieldrin, PCB 153 and PCB 52, so it acts as a sampler for non-polar compounds. The highest uptake rate of hydrophobic compounds by Chemcatcher was observed for analytes with log octanol-water partition coefficient (K O W ) between 4.5 and 7.5. Laboratorybased studies using passive samplers to assess the potential for bioaccumulation could provide robust and reliable information at relatively low cost compared to biomonitoring data. Laboratory data obtained using passive samplers could be related to accumulation under field conditions where field assessments are required.

No abstract

1 The effect of crude honeybee (Apis mellifera)venom on the skeletal, smooth as well as cardiac muscles were studied in this investigation. 2 Perfusion of gastrocnemius-sciatic nerve preparation of frogs with 1 mg/ml venom solution has weakened the mechanical contraction of the muscle without recovery. Blocking of nicotinic receptors with 3 mg/ml flaxedil before bee venom application sustained normal contraction of gastrocnemius muscle. 3 The electrical activity of duodenum rabbits was recorded before and after the application of 1 mg/ml venom solution. The venom has depressed the amplitude of the muscle contraction after 15 min pretreatment with atropine nearly abolished the depressor effect of the venom on smooth muscle. 4 In concentrations from 0.5-2 mg/ml, bee venom caused decrease of heart rate of isolated perfused toad heart. This bradycardia was accompanied by elongation in the P-R interval. A gradual and progressive increase in the R-wave amplitude reflected a positive inotropism of the venom. Application of 5 mg/ml verapamil, a calcium channels blocking agent, abolished the noticed effect of the venom. 5 Marked electrocardiographic changes were produced within minutes of the venom application on the isolated perfused hearts, like marked injury current (elevation or depression of the S-T segment), atrioventricular conduction disturbances and sinus arrhythmias. Atropine and nicotine could decrease the toxic effect of the venom on the myocardium. 6 Results of the present work lead to the suggestion that bee venom is mediated through the peripheral cholinergic neurotransmitter system. General neurotoxicity of an inhibitory nature involving the autonomic as well as neuromuscular system are established as a result of the venom, meanwhile a direct effect on the myocardium membrane stabilization has been suggested.

Background: Scorpion venom contains various biomolecules with potential therapeutic values against different diseases, including cancer. The present study was carried out to assess the antitumor efficacy of Androctonus australis crude venom using both in vitro and in vivo approaches. Methodology: For in vitro assay, the cytotoxic effect of different venom concentrations was determined against HCT116, HepG2, MCF-7, and PC-3 as cancer cell lines and normal WISH cell line. The in vivo assay was carried out by the I.P. transplantation of EAC into Swiss albino female mice, followed by the I.P. injection of the venom at the sublethal dose 1/10 LD 50 (0.025 mg/kg BW) compared to cisplatin (2 mg/kg BW), and both normal and EAC control groups were also included. The analysis of ascetic fluid tumor, survival study, and hematological, biochemical, antioxidant, and histopathological assays was evaluated in control and treated animal groups. Results: Our in vitro results revealed that the A. australis venom had a selective promising activity against MCF-7 cells (IC 50 = 19.71 μg/mL). Moreover, it was less cytotoxic on WISH cells. The in vivo data showed that A. australis venom exhibited a highly significant decrease in tumor volume, and viable tumor cell count, and increased the duration of lifespan compared to the EAC control group. The venom significantly enhanced both hematological and biochemical measurements compared to the EAC control group. Conclusion: The results revealed that the A. australis venom exhibited in vitro and in vivo antitumor activities. Further venomics studies are needed to functionally characterize the active molecules from this scorpion venom and study their mode of action on cancer cells to develop them into potential anticancer agents.

No abstract