Duje Lisičić

Radioprotective effects of propolis and quercetin in γ-irradiated mice evaluated by the alkaline comet assay

The radioprotective effects of ethanolic extract of propolis (EEP) and quercetin on the white blood cells of the whole-body irradiated CBA mice were investigated. Irradiation was performed using a gamma-ray source ((60)Co), and absorbed dose was 9 Gy. The efficiency of test components was evaluated when given intraperitoneally (ip) at a dose of 100 mg kg(-1) for 3 consecutive days before and/or after irradiation. Moreover, possible genotoxic effects of test components were also assessed on non-irradiated animals. For each experimental group leukocyte count was determined and the primary DNA damage in leukocytes was assessed using the alkaline comet assay. The higher efficiency of EEP and quercetin was observed when given preventively. The results suggest that propolis and quercetin given to mice before irradiation protect their white blood cells from lethal effects of irradiation and diminish primary DNA damage as confirmed by the alkaline comet assay. Positive results obtained on gamma-irradiated mice given EEP and quercetin, complementary with our earlier observations on survival of irradiated mice, indicate that these compounds could be considered effective non-toxic radioprotectors. The exact mechanisms of radioprotection by these compounds and their effects on DNA repair processes are still to be elucidated.

Radioprotective Effects of Quercetin and Ethanolic Extract of Propolis in Gamma-Irradiated Mice

Radioprotective Effects of Quercetin and Ethanolic Extract of Propolis in Gamma-Irradiated Mice The aim of this study was to assess radioprotective effects of quercetin and the ethanolic extract of propolis (EEP) in CBA mice exposed to a single radiation dose 4 Gy (60Co). The mice were treated with 100 mg kg-1 quercetin or EEP a day for three consecutive days either before (pre-treatment) or after gamma-irradiation (therapy). Leukocyte count was determined in blood drawn from the tail vein, and DNA damage in leukocytes was assessed using the alkaline comet assay. Genotoxic effects of the test compunds were also evaluated in non-irradiated mice. The levels of radioprotection provided by both test compounds were compared with those established in mice that were given chemical radioprotector S-(2-Aminoethy1)isothiouronium bromide hydrobromide (AET). Mice that received pre-treatment were less sensitive to irradiation. Mice given the post-irradiation therapy showed a slight but not significant increase in total leukocyte count over irradiated negative control. Quercetin showed better protective properties than EEP in both pre-treatment and therapy, and activated a higher number of leukocytes in non-irradiated mice. The alkaline comet assay suggests that both natural compounds, especially when given as pre-treatment, protect against primary leukocyte DNA damage in mice. At tested concentrations, EEP and quercetin were not genotoxic to non-irradiated mice. AET, however, caused a slight but not significant increase in DNA damage. Although the results of this study show the radioprotective potential of the test compounds, further investigation is needed to clarify the underlying protection mechanisms. Primjena alkalnog kometnog testa u istraživanju radioprotektivnih učinaka alkoholnog ekstrakta propolisa i kvercetina na miševima ozračenim gama-zračenjem

Fast and furious: effects of body size on strike performance in an arboreal viper Trimeresurus (Cryptelytrops) albolabris

Body size has a pervasive effect on animal functioning and life history with size dependent changes in performance and physiology throughout ontogeny being common in many ectothermic vertebrates. However, as selection on juvenile life history stages is strong, juveniles often offset the disadvantages of small body size by disproportionate levels of performance. Here, we investigate size-related changes in defensive strike performance in an arboreal pit viper, Trimerusurus (Cryptelytrops) albolabris. Our data show a significant negative allometry in the scaling of head dimensions and head mass to body mass. However, strike velocity and strike distance are independent of body mass, with juveniles in our sample striking as fast and as far as adults. In contrast to model predictions suggesting that acceleration capacity should decrease with increasing body mass, acceleration capacity increases with snake body mass. Our results suggest that this is the result of a negative allometric scaling of head mass combined with an isometric scaling of the dorsal epaxial musculature. Finally, our data show a significant sexual dimorphism in body size and strike velocity with females being heavier and striking faster independent of the dimorphism in body size.

Synergistic Effects of Irinotecan and Flavonoids on Ehrlich Ascites Tumour-Bearing Mice

Swiss albino mice were given Ehrlich ascites tumour cells (1 × 10(6)) intraperitoneally. For survival analysis and tumour growth analysis, the mice were administered quercetin and naringin (100 mg/kg) daily for 3 consecutive days, beginning on the third day after intraperitoneal (i.p.) injection of Ehrlich ascites tumour cells (1 × 10(6)). Irinotecan was administered ip at a dose of 50 mg/kg on days 1, 13 and 19. For the analysis of cell types and differential count of cells present in the peritoneal cavity, peripheral whole-blood leucocyte count and the comet assay, the mice were treated therapeutically with quercetin and naringin (100 mg/kg) and irinotecan (50 mg/kg) daily for 3 consecutive days beginning on third day after i.p. injection of Ehrlich ascites tumour cells (1 × 10(6)). We observed the synergistic anti-tumour effect expressed as the median survival time of mice treated with naringin in combination with irinotecan. All test components inhibited tumour growth and increased lifespan of mice except quercetin. The total number of cells present in the peritoneal cavity of mice significantly decreased in all treatments except quercetin. Single irinotecan and irinotecan combined with naringin had the highest DNA-damaging potential on peripheral blood leucocytes and lowest primary DNA damage, both in the kidney and liver cells as measured by the alkaline comet assay. Our results showed enhanced anti-tumour activity of irinotecan in combined treatment with flavonoids to reduce the deteriorating reaction of cytostatic drugs.

Effect of competition on habitat utilization in two temperate climate gecko species

Competition over spatial niche utilisation is one of most common competitive interactions between species in sympatry. Moreover, competitive interactions may involve age classes, and can fluctuate temporally. Consequently, evasive strategies that enable co-existence are likely to be important in the evolution of species assemblages. Here we investigate a system of two co-existing species of temperate geckos with similar ecologies (the house gecko, Hemidactylus turcicus and the wall gecko, Tarentola mauritanica), providing an opportunity to study the effect of species interactions. Juveniles and adults of both species were investigated throughout their daily and annual cycle to explore the effect of inter- and intra-specific interactions on microhabitat use. The two species showed differences in habitat use for both age classes in sympatry. In sympatry, T. mauritanica uses more open habitats and is more active. In contrast, H. turcicus is found in more closed habitats, closer to the ground and to vegetation cover. In allopatry, H. turcicus was observed in more open habitats, closer to the ground, and to vegetation cover, when compared to the population in sympatry with T. mauritanica. These differences in habitat usage were significant for both age classes. Moreover, there were differences, both in sympatry and in allopatry, between age classes that were dependent on season. In conclusion, the presence of a competitor induces a spatial shift in individuals of both age classes of H. turcicus. Observed plasticity in habitat utilisation in both age classes of H. turcicus is used to argue for the invasive potential of this species.

DNA damage and repair after exposure to sevoflurane in vivo, evaluated in Swiss albino mice by the alkaline comet assay and micronucleus test

The relationship between DNA damage and repair of peripheral blood leukocytes, liver, kidney and brain cells was investigated in Swiss albino mice (Mus musculus L.) after exposure to sevoflurane (2.4 vol% for 2 h daily, for 3 days). Genetic damage of mouse cells was investigated by the comet assay and micronucleus test. To perform the comet assay, mice were divided into a control group and 4 groups of exposed mice sacrificed on day 3 of the experiment, at 0, 2, 6 or 24 h after the last exposure to sevoflurane. Mean tail length (TL), tail moment (TM), and tail intensity (TI) values were significantly higher in exposed mice (all examined organs) than in the control group. Significant DNA damage immediately after exposure to sevoflurane was observed in leukocytes. Damage induction in the liver, kidney, and brain occurred 6 h later than in leukocytes, as expected according to the toxicokinetics of the drug, where blood is the first compartment to absorb sevoflurane. However, none of the tested tissues revealed signs of repair until 24 h after the exposure. To distinguish the unrepaired genome damage in vivo, the micronucleus test was applied. Number of micronuclei in reticulocytes showed a statistically significant increase, as compared with the control group at all observed times after the treatment.

Carbendazim combined with imazalil or cypermethrin potentiate DNA damage in hepatocytes of mice

Traces of pesticides imazalil, cypermethrin and carbendazim are detected in plants used for human consumption. To explore whether their application in oral combinations will induce DNA breaks in hepatocytes, a subchronic in vivo experiment was performed in Swiss mice. Doses of 10 mg kg–1 of imazalil (im) and cypermethrin (cy), and 20 mg kg–1 of carbendazim (car) and their combinations (im, 10 mg kg–1 + cy, 10 mg kg–1; im, 10 mg kg–1 + car, 20 mg kg–1; car, 20 mg kg–1 + cy, 10 mg kg–1) were applied daily for 28 days. Afterward, DNA damage in hepatocytes was evaluated by comet assay. Individually, imazalil and cypermethrin damaged DNA at alkali-labile sites, while the tail moment (TM) of carbendazim alone was similar to control but with higher tail length. In combination with carbendazim clastogen, properties of imazalils and cypermethrins were potentiated compared to all other treatments and control. There were pronounced sex differences in pattern of fragmentation between treated groups. Higher long tail nuclei (LTN) in females indicate that certain cells in females were especially prone to total nucleus disintegration. Due to synergistic effects, low environmentally present concentrations of imazalil and cypermethrin in food, and especially their mixtures with carbendazim have genotoxic potential that could be particularly dangerous over prolonged exposure in mammalian organism.

Classification Modeling of Physiological Stages in Captive Balkan Whip Snakes Using Blood Biochemistry Parameters

Abstract We studied captive Balkan Whip Snakes (Hierophis gemonensis) to determine blood biochemical parameters that are useful indicators of physiological status during different periods of the biological cycle, including pre- and posthibernation, hibernation, sexual activity, and normal activity. In addition to classic statistical analyses, six machine-learning methods using 10 times 10-fold cross-validation evaluation were used to determine the best classification model for the blood biochemistry data. Results of the machine-learning models indicated that using three of the blood biochemistry variables simultaneously—urea, glucose, and lactate dehydrogenase—is enough to discriminate accurately between different physiological conditions during the biological cycle. This approach clarifies the role and importance of physiological processes, which show diversity of functional characteristics of various biochemical parameters in ecological relation to snakes held under laboratory conditions mimicking natural environmental changes.

Prevention of peritoneal carcinomatosis in mice with combination hyperthermal intraperitoneal chemotherapy and IL-2

Purpose: The purpose of this study was to investigate the effect of local chemoimmunotherapy and hyperthermal intraperitoneal chemotherapy (HIPEC) in a mouse model of induced peritoneal carcinomatosis. Material and methods: Peritoneal carcinomatosis in mice was produced by intraperitoneal implantation of MCa cells (5 × 103). Interleukin-2 (4.1 × 104 IU/mouse) was injected into the abdominal cavity of mice at day 7 and 3 before implantation of tumour cells. Immediately after implantation of MCa cells mice were treated twice with 2 ml of saline that was heated either at 37°C or 43°C and cytostatics (doxorubicin 20 mg kg−1, cisplatin 10 mg kg−1, mitomycin 5 mg kg−1, or 5-FU 150 mg kg−1). We followed the survival of animals and side effects appearing with different forms of treatment. Results: Combined treatment with Interleukin-2 (IL-2) and cytostatics (5-FU, CIS or MIT) significantly affected the development of peritoneal carcinomatosis and increased the survival of mice (ILS% – 37°C = 29.88, 199.32, and 108.52, ILS% – 43°C = 62.69, 260.50, and 178.05, respectively). However, intraperitoneal chemotherapy on survival time of mice with DOX + IL-2 was ineffective as compared with DOX alone. Conclusion: We would like to stress that treatment with IL-2 prior to tumour diagnosis is not clinically practical, rather, the manuscript attempts to describe an experimental proof of principle. Results suggest the synergistic effect of hyperthermia, chemotherapy and immunotherapy; IL-2 significantly increases antitumor activity of hyperthermic chemotherapy and survival rate of mice with peritoneal carcinomatosis.

The effects of prometryne on subchronically treated mice evaluated by SCGE assay.

Prometryne is a methylthio-s-triazine herbicide used to control annual broadleaf and grass weeds in many cultivated plants. Significant traces are documented in environment, mainly water, soil and plants used for human and domestic animal nutrition. Data on the toxic effects of prometryne and other methylthio-s-triazine have scorcely been published. The goal of this study was to investigate if prometryne, applied orally, could induce DNA damage in mouse leukocytes, in subchronical in vivo experimental design. Three different doses of prometryne were applied per os repeatedly every 48 hours. After the 7th dose (day 14) and the 14th dose (day 28) blood leucocytes were analyzed by alkaline Single Cell Gel Electrophoresis (Comet) assay. The results of three different comet parameters showed general increase in Olive tail moment, tail length and tail intensity values in treated groups of animals. The increase in measured values was almost proportional to the dose received and the time of exposure. We conclude that prometryne or its metabolic residues have the potential to induce processes that cause genotoxic effects on leukocytes on mice in in vivo repeated exposure.