Published Journal Articles
Scorpion Fauna and Scorpionism in Zakho Province of Northern Iraq
Commagene Journal of Biology (Issue : 4) (Volume : 1)
Information regarding scorpion diversity and their envenoming within Iraq in general, and the Northern Iraq in particular, is limited. The number and distribution of scorpion sting cases and some details of the scorpion fauna of Zakho province were reported for the first time in this study. Overall, 2675 scorpion sting cases were reported between 2008 and 2017 consisting of 1362 male victims (51%) and 1313 female (49%). The highest percentage of victims was between 15 and 49 years old and accounted for 59% of the overall incidence. The highest incidence of scorpion sting cases occurred in the summer, particularly in July when 537 cases were reported. In total, 85 scorpions belonging to two families (Scorpionidae and Buthidae) were captured in the present study. Of the collected samples, Scorpio maurus 47 (55%) was the most abundant followed by Hottentotta saulcyi 28 (33%), and Androctonus crassicauda 10 (12%).
Philanthotoxin Analogues That Selectively Inhibit Ganglionic Nicotinic Acetylcholine Receptors with Exceptional Potency
Search Results Web result with site links Journal of Medicinal Chemistry (Issue : 13) (Volume : 62)
Philanthotoxin-433 (PhTX-433) is an active component of the venom from the Egyptian digger wasp, Philanthus triangulum. PhTX-433 nonselectively inhibits several excitatory ligand-gated ion channels, and we recently showed that its synthetic analogue, PhTX-343, exhibits strong selectivity for neuronal over muscle-type nicotinic acetylcholine receptors (nAChRs). Here, we examined the action of 17 analogues of PhTX-343 against ganglionic (α3β4) and brain (α4β2) nAChRs expressed in Xenopus oocytes by using a two-electrode voltage clamp at −100 mV. IC50 values for PhTX-343 inhibition of α3β4 and α4β2 receptors were 7.7 and 80 nM, respectively. All the studied analogues had significantly higher potency at α3β4 nAChRs with IC50 values as low as 0.16 nM and with up to 91-fold selectivity for α3β4 over α4β2 receptors. We conclude that PhTX-343 analogues displaying both a saturated ring and an aromatic moiety in the hydrophobic headgroup of the molecule demonstrate exceptional potency and selectivity for α3β4 nAChRs.
Insect toxins – selective pharmacological tools and drug/chemical leads
Current Opinion in Insect Science (Volume : 30)
Insect toxins comprise a diverse array of chemicals ranging from small molecules, polyamines and peptide toxins. Many target nervous system and neuromuscular ion channels and so rapidly affect the behaviour of animals to which the toxin is applied or injected. Other modes of action have also been identified. Wasps, bees, flies, beetles and ants generate a rich arsenal of channel-active toxins, some of which offer selective pharmacological probes that target particular ion channels, while others act on more than one type of channel. Philanthotoxins from the digger wasp have been fruitful in adding to our understanding of ligand-gated ion channels both in the nervous system and at neuromuscular junctions. Fire ants produce the toxic alkaloid solenopsin, a molecule which has stimulated attempts to generate synthetic compounds with insecticidal activity. Apamin from bee venom targets calcium-activated potassium channels, which can in turn influence the release of neuropeptides. Melittin, another bee venom component, is a membrane-acting peptide. The saliva of the assassin bug contains toxins that target the voltage-gated calcium channels of their insect prey. Certain beetles produce diamphotoxin, a haemolytic peptide toxin with traditional use as an arrow poison and others generate leptinotarsin with similar properties. Mastoparan is a powerful peptide toxin present in the venom of wasps. Its toxic actions can be engineered out leaving a potent antimicrobial molecule of interest. In this short review we describe the actions of selected insect toxins and evaluate their potential as neuroactive pharmacological tools, candidate lead molecules for insect control and therapeutic candidates with potential antimicrobial, antiviral and anti-cancer applications.
Prevalence and Predictors of Tobacco Use Among School Adolescents in Zakho, Kurdistan Region of Iraq
Science Journal of University of Zakho (Issue : 3) (Volume : 6)
Knowledge regarding the smoking prevalence among the Kurdistan general population is not clear, at least for males. Here in the Kurdistan Youth Smoking Survey and Behaviours (KYSS&B) we tried to further expand our knowledge about the smoking profile of school students across Kurdistan. Five hundred students from four Zakho male basic schools were taken to participate in the study to determine the prevalence of smoking and socio-demographical factors associating with smoking among students aged 12 to 15 years. The KYSS&B questionnaire included various parameters such as age, gender, friends, parent history and blood groups. This study showed that the prevalence of students who ever tried smoking was 74%; about 65% of them started at age 12 years or less. Although the majority of participants (95%) knew that smoking is harmful and had negative impact on human health, 18% of them thought that they will never quit smoking. The study concluded that there was no strong association between family monthly income, parent education level and blood groups. On the other hand, the three most critical factors connected with smoking habit reported by students were age, peer influence and father smoking.
Block of nicotinic acetylcholine receptors by philanthotoxins is strongly dependent on their subunit composition
Scientific Reports (Volume : 6)
Philanthotoxin-433 (PhTX-433) is an active component of the venom from the Egyptian digger wasp, Philanthus triangulum. PhTX-433 inhibits several excitatory ligand-gated ion channels, and to improve selectivity two synthetic analogues, PhTX-343 and PhTX-12, were developed. Previous work showed a 22-fold selectivity of PhTX-12 over PhTX-343 for embryonic muscle-type nicotinic acetylcholine receptors (nAChRs) in TE671 cells. We investigated their inhibition of different neuronal nAChR subunit combinations as well as of embryonic muscle receptors expressed in Xenopus oocytes. Whole-cell currents in response to application of acetylcholine alone or co-applied with PhTX analogue were studied by using two-electrode voltage-clamp. α3β4 nAChRs were most sensitive to PhTX-343 (IC50 = 12 nM at −80 mV) with α4β4, α4β2, α3β2, α7 and α1β1γδ being 5, 26, 114, 422 and 992 times less sensitive. In contrast α1β1γδ was most sensitive to PhTX-12 along with α3β4 (IC50 values of 100 nM) with α4β4, α4β2, α3β2 and α7 being 3, 3, 26 and 49 times less sensitive. PhTX-343 inhibition was strongly voltage-dependent for all subunit combinations except α7, whereas this was not the case for PhTX-12 for which weak voltage dependence was observed. We conclude that PhTX-343 mainly acts as an open-channel blocker of nAChRs with strong subtype selectivity.