Neciljana toksičnost novih insekticida

Humans have used insecticides since ancient times. The spectrum and potency of available insecticidal substances has greatly expanded since the industrial revolution, resulting in widespread use and unforeseen levels of synthetic chemicals in the environment. Concerns about the toxic effects of these new chemicals on non-target species became public soon after their appearance, which eventually led to the restrictions of use. At the same time, new, more environmentally-friendly insecticides have been developed, based on naturally occurring chemicals, such as pyrethroids (derivatives of pyrethrin), neonicotinoids (derivatives of nicotine), and insecticides based on the neem tree vegetable oil (Azadirachta indica), predominantly azadirachtin. Although these new substances are more selective toward pest insects, they can still target other organisms. Neonicotinoids, for example, have been implicated in the decline of the bee population worldwide. This review summarises recent literature published on non-target toxicity of neonicotinoids, pyrethroids, and neem-based insecticidal substances, with a special emphasis on neonicotinoid toxicity in honeybees. We also touch upon the effects of pesticide combinations and documented human exposure to these substances.Ljudi su upotrebljavali insekticide od davnih vremena. Spektar i potentnost dostupnih insekticidnih supstancija značajno su se proširili od industrijske revolucije, vodeći širokoj upotrebi i neviđenim količinama sintetskih kemikalija u okolišu. Zbog toksičnih učinaka tih novih kemikalija na neciljane vrste javnost je ubrzo pokazala veliku zabrinutost, što je dovelo do ograničenja u korištenju tih insekticidnih supstancija. Istovremeno dolazi do razvoja novih metoda u održivoj poljoprivredi, među kojima i razvoj novih insekticida na osnovi prirodno prisutnih kemikalija, poput piretroida (derivati piretrina iz suncokreta) i neonikotinoida (derivati nikotina). Dodatni su primjer insekticidi na bazi biljnog ulja iz drveta nima (Azadirachta indica), dominantno azadiraktin. Iako su te nove supstancije selektivnije prema insektima, poteškoće nastaju s njihovom neciljanom toksičnošću, poput one neonikotinoida, koji su utjecali na pad populacije pčela na globalnoj razini. Ovaj pregled sažima nedavnu literaturu o neciljanoj toksičnosti neonikotinoida, piretroida i insekticidnih supstancija na bazi nima, s naglaskom na toksičnosti neonikotinoida za pčele. Također ćemo se dotaknuti učinaka mješavina pesticida, kao i zabilježene ljudske izloženosti tim supstancijama

Fluorescencijska hibridizacija in situ (FISH) u detekciji kromosomskih oštećenja nastalih kao posljedica profesionalne izloženosti ionizirajućem zračenju

For more than two decades, chromosome aberration analysis has been used in biomonitoring of occupational and environmental exposure to ionising radiation. Chromosome aberration analysis is a method used to detect unstable aberrations in the lymphocytes of irradiated personnel. In turn, stable chromosome aberrations that arise some time after exposure are detected using the multicolour fluorescence in situ hybridisation. This is a technique which dyes each pair of chromosomes with different colour. Due to the dynamics of unstable aberration formation, chromosome aberration analysis is more suitable for genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives information on chromosome instability caused by long-time occupational exposure to ionising radiation. Considering the high cost of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.Posljednjih dvadesetak godina analiza kromosomskih aberacija rabi se kao glavna citogenetička tehnika u biodozimetriji osoba profesionalno izloženih zračenju. Metoda omogućava utvrđivanje prisutnosti nestabilnih tipova oštećenja u limfocitima ozračenih osoba. Međutim, njome nije moguće istodobno utvrditi i prisutnost stabilnih tipova oštećenja kao što su translokacije. U tu svrhu potrebno se koristiti višebojnom fluorescencijskom hibridizacijom in situ (mFISH) kojom je moguće svaki par kromosoma obojiti drugom bojom. Zbog same dinamike nastanka nestabilnih kromosomskih oštećenja analiza kromosomskih aberacija, kao citogenetička tehnika, prikladnija je za procjenu genomskih oštećenja u kratkom vremenu nakon ozračivanja, dok bi FISH mogao naći primjenu u detekciji stabilnih oštećenja genoma koja nastaju kao posljedica dugotrajne profesionalne izloženosti zračenju. Međutim, zbog visokih troškova same tehnike i zahtjevnosti njezine izvedbe, FISH kao tehnika u biodozimetriji rabila bi se samo u slučajevima kada podatke o stupnju oštećenja genoma nije moguće dobiti primjenom ni jedne druge citogenetičke tehnike

Genetically Modified Orgnisms in Food - Production, Detection and Risks

Prva genetički preinačena (engl. genetically modified - GM) biljka bio je duhan otporan na antibiotike. Dobiven je 1983. godine. No, tek 1996. godine genetički preinačena biljka prvi put se našla u slobodnoj prodaji. Riječ je o rajčici s produljenim trajanjem. Godine 2003. više od 67 milijuna hektara obradivih površina bilo je zasijano GM usjevima. Da bi se proizvela takva biljka, potrebno je iz organizma donora izolirati gen za željeno svojstvo. Tom genu potrebno je dodati promotorsku sekvencu, terminator i gen marker te dobiveni konstrukt ubaciti u biljnu stanicu. U specifičnim uvjetima uzgoja dobivene transformirane stanice potiču se na diobu i izrastaju u čitavu biljku koja u sebi nosi gen za željeno svojstvo. U svrhu utvrđivanja prisutnosti GM organizama u hrani danas se najčešće rabi tehnika lančane reakcije polimerazom (engl. polimerase chain reaction - PCR). No, da bi se ona mogla uspješno primijeniti, potrebno je točno poznavati barem dio sekvence DNS koja je transformacijom ubačena u novonastalu biljku, što katkada može biti ozbiljan problem. Posljednjih dana svjedoci smo žestokih sukobljavanja u vezi sa sigurnosti konzumacije proizvoda koji sadržavaju genetički preinačene sastojke. Kao neki od razloga protiv navode se alergijske reakcije na GM sastojke, njihova toksičnost i opasnost GM organizama za biološku raznolikost i ravnotežu unutar ekosustava. Nedvojbeno je da bi vodeću riječ u ocjeni opasnosti GM organizama trebala imati znanost bazirana na činjenicama, a što nažalost nije uvijek slučaj.The first genetically modified plant (GMP) was a tobacco resistant to antibiotics in 1983. In 1996, the first genetically altered crop, a delayed-ripening tomato was commercially released. In the year 2003, the estimated global area of GM crops for was 67.7 million hectares. To produce such a plant a gene of interest has to be isolated from the donor. Together with a promoter, terminator sequence and marker gene it has to be introduced into the plant cell which is then stimulated to generate a whole GMP expressing new characteristics (herbicide/insect resistance, delayed ripening). The last few months have seen a strong public debate over genetically modified organisms which has raised scientific, economic, political, and ethical issues. Some questions concerning the safety of GMPs are still to be answered, and decisions about their future should be based on scientifically validated information

Alternativni pristup mjerenju koncentracije nanočestica ZnO u kulturama humanih limfocita - spoj elektrokemije i testova genotoksičnosti

Nanoparticle use has increased radically raising concern about possible adverse effects in humans. Zinc oxide nanoparticles (ZnO NPs) are among the most common nanomaterials in consumer and medical products. Several studies indicate problems with their safe use. The aim of our study was to see at which levels ZnO NPs start to produce adverse cytogenetic effects in human lymphocytes as an early attempt toward establishing safety limits for ZnO NP exposure in humans. We assessed the genotoxic effects of low ZnO NP concentrations (1.0, 2.5, 5, and 7.5 μg mL-1) in lymphocyte cultures over 14 days of exposure. We also tested whether low and high-density lymphocytes differed in their ability to accumulate ZnO NPs in these experimental conditions. Primary DNA damage (measured with the alkaline comet assay) increased with nanoparticle concentration in unseparated and high density lymphocytes. The same happened with the fragmentation of TP53 (measured with the comet-FISH). Nanoparticle accumulation was significant only with the two highest concentrations, regardless of lymphocyte density. High-density lymphocytes had significantly more intracellular Zn2+ than light-density ones. Our results suggest that exposure to ZnO NPs in concentrations above 5 μg mL-1 increases cytogenetic damage and intracellular Zn2+ levels in lymphocytes.S naglim porastom primjene nanočestica raste i mogućnost njihova štetna djelovanja u ljudi. Nanočestice cinkova oksida najčešći su oblik nanomaterijala u potrošačkim proizvodima i lijekovima. Nekoliko je istraživanja već upozorilo na probleme vezane uz njihovu sigurnu primjenu. Cilj je ovoga istraživanja bio utvrditi pri kojim razinama nanočestice ZnO počinju štetno citogenetski djelovati na humane limfocite i time otvoriti pitanje utvrđivanja graničnih razina za sigurnu primjenu nanočestica ZnO u ljudi. Stoga smo istražili genotoksične učinke niskih koncentracija nanočestica ZnO (1,0; 2,5; 5 i 7,5 μg mL-1) izloživši kulture humanih limfocita njihovu djelovanju tijekom 14 dana. Uz to smo izmjerili razlikuju li se limfociti niske gustoće od onih visoke gustoće u sposobnosti akumuliranja nanočestica ZnO pri istim eksperimentalnim uvjetima. Primarno oštećenje DNA (izmjereno alkalnim komet-testom) povećalo se s rastom koncentracije nanočestica u limfocitima koje nismo razdvojili po gustoći te u limfocitima visoke gustoće. Slično smo povećanje zamijetili s fragmentacijom tumorskoga supresorskoga gena TP53 (izmjereno komet-FISH testom). Nakupljanje Zn2+ iona u stanicama bilo je značajno samo kod primjene dviju najviših koncentracija nanočestica ZnO, bez obzira na gustoću limfocita. Osim toga, limfociti visoke gustoće iskazali su i značajno više razine unutarstaničnoga Zn2+ od limfocita niske gustoće. Naši rezultati upozoravaju na to da se izlaganjem razinama nanočestica ZnO višima od 5 μg mL-1 značajno povisuju razine Zn2+ u limfocitima te se povećava oštećenje tih stanica i njihova genoma

Genotoxic Potential of Dentin Bonding Agents

Svrha rada bila je ispitati genotoksično djelovanje pet dentinskih adheziva: Adper Single Bonda, Adper Single Bonda 2, Prompt L-popa, Excitea i OptiBonda Solo Plus. Ispitivanje genotoksičnosti provedeno je na humanim limfocitima periferne krvi u uvjetima in vitro, ispitane koncentracije adheziva bile su 0,2, 0,5 i 5 μg/ml, a testirana vremena eluacije 1 sat, 24 sata i 5 dana. Genotoksičnost adheziva ispitivala se citogenetičkom metodom - analizom strukturnih aberacija kromosoma, dakle, određivanjem ukupnog broja kromosomskih lomova, kromatidnih lomova i acentričnih fragmenata. Rezultati pokazuju genotoksičnost OptiBonda Solo Plus već u koncentraciji 0,2 μg/ml i to nakon 24-satne eluacije, zatim OptiBonda Solo Plus u koncentraciji 0,5 μg/ml nakon jednosatne eluacije, OptiBonda Solo Plus, Adper Single Bonda 2 i Excitea u koncentraciji 0,5 μg/ml nakon jednodnevne eluacije. U koncentraciji 5 μg/ml nakon jednosatne eluacije genotoksičnost su pokazali OptiBond Solo Plus, Excite, Adper Single Bond 2 i Adper Single Bond, a nakon jednodnevne eluacije svi su ispitivani adhezivi pokazali genotoksičnost. Iz rezultata je jasno da enotoksičnost raste s porastom koncentracije adheziva, a smanjuje se s vremenom. Najveća genotoksičnost zabilježena je nakon 24-satne eluacije.The aim of this study was to examine the genotoxic activity of five dentin bonding agents: Adper Single Bond, Adper Single Bond 2, Prompt L-pop, Excite and Opti-Bond Solo Plus. This in vitro study was performed on human lymphocytes from peripheral blood, and the concentrations of dentin bonding agents tested were 0.2, 0.5 i 5 μg/ml, and elution times tested were 1 hour, 24 hours and 5 days. Genotoxicity testing was done using the Structural chromosomal aberration analysis cytogenic method , which determined the complete number of chromosome breaks, chromatide breaks and acentric fragments. The results showed genotoxicity of Opti-Bond Solo Plus in the 0.2 μg/ml concentration after a 24-hour elution period, then OptiBond Solo Plus in the 0.5 μg/ml concentration after a 1 hour elution period and OptiBond Solo Plus, Adper Single Bond 2 and Excite in the 0.5 μg/ml concentration after a 1 day elution period. In the 5 μg/ml concentration after 1 hour of elution, genotoxic potential was observed in cultures with OptiBond Solo Plus, Excite, Adper Single Bond 2 and Adper Single Bond, while all dentin bonding agents showed genotoxicity at that highest concentration but after 1 day of elution. From the results it is obvious that genotoxicity increases with the concentration of the dentin bonding agent, and decreases over time. The highest genotoxicity was observed after a 24-hour-elution period

Morphological features and comet assay of green and brown hydra treated with aluminium

Abstract Hydras are simple aquatic organisms, members of the phylum Cnidaria. Green hydra (Hydra viridissima Pallas) is endosymbiotic and brown hydra (Hydra oligactis Pallas) is a non-symbiotic species. Aluminium is one of the most abundant elements in the Earth's crust, but its effects upon living organisms have not been much studied until recently. The aim of this research was to explore the potential environmental effects of aluminium ions by studying aluminium-induced changes in two closely related hydra species, and to trace the extent damage caused. For the first time, a modified alkaline comet assay was used to study primary DNA damage in green and brown hydra cells. Aluminium toxicity triggered mortality, morphological, behavioral and DNA changes. DNA tail length and intensity changes were greater in brown than in green hydras, but behavioral responses to the presence of aluminium ions were observed more rapidly in green hydra. The toxicity also affected reproduction. Brown hydra was more susceptible to aluminium than green hydra, confirming the evolutionary advantage provided by symbiosis. Biomonitoring protocols using hydra and the comet assay could be developed to provide a valuable and rapid method for determining the quality of freshwater

Oksidacijsko-redukcijska neravnoteža uzrokovana pesticidima: pregled istraživanja vezanih uz OPENTOX

Pesticides are a highly diverse group of compounds and the most important chemical stressors in the environment. Mechanisms that could explain pesticide toxicity are constantly being studied and their interactions at the cellular level are often observed in well-controlled in vitro studies. Several pesticide groups have been found to impair the redox balance in the cell, but the mechanisms leading to oxidative stress for certain pesticides are only partly understood. As our scientific project “Organic pollutants in environment – markers and biomarkers of toxicity (OPENTOX)” is dedicated to studying toxic effects of selected insecticides and herbicides, this review is focused on reporting the knowledge regarding oxidative stress-related phenomena at the cellular level. We wanted to single out the most important facts relevant to the evaluation of our own findings from studies conducted on in vitro cell models.Pesticidi su raznovrsna skupina spojeva i glavni izvor stresa u okolišu. Mehanizmi kojima se nastoji objasniti toksičnost pesticida kontinuirano se istražuju, a njihove interakcije na staničnoj razini često se promatraju u sklopu kontroliranih in vitro istraživanja. Za nekoliko skupina pesticida utvrđeno je da narušavaju oksidacijsko-redukcijsku ravnotežu u stanici, a mehanizmi koji vode do nastanka oksidacijskoga stresa za pojedine su pesticide još uvijek nedovoljno poznati. Budući da je naš znanstveni projekt „Organska zagađivala u okolišu-markeri i biomarkeri toksičnosti (OPENTOX)“ posvećen istraživanju toksičnih učinaka odabranih insekticida i herbicida, ovaj pregledni rad usmjeren je na prikaz spoznaja koje se odnose na promjene uzrokovane stresom na staničnoj razini. Željeli smo izdvojiti najvažnije činjenice koje su bitne za procjenu vlastitih rezultata istraživanja provedenih na in vitro staničnim modelima