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Monika Derda

Publications and source records attributed to Monika Derda.

9 recordsLinked to original sources

Evaluation of effects of albendazole on the kinetics of cytosolic glutathione transferase in skeletal muscles during experimental trichinellosis in mice.

In this study, the effect of trichinellosis as well as the effect of albendazole treatment on the kinetics of substrate saturation of cytosolic glutathione transferase (GST) in the skeletal muscles from infected mice was examined because the idea of multifunctional mode of action of anthelmintic drugs was considered. Our results pointed out to the influence of trichinellosis and albendazole treatment on the quaternary structure of GST in mouse muscles. A double reciprocal plot of GST saturation in control mice was biphasic with apparent low and high K (m) values equal to 0.54 and 1.0 mM, respectively. Infection with Trichinella spiralis in the third week postinfection caused a 2.3-fold increase in the high K (m) value and at the same time a 2.8-fold decrease in the low K (m). In the sixth week postinfection, the high K (m) value was unchanged, but the low K (m) value increased 2.3 times. Calculated from the double reciprocal plot of GST substrate saturation in muscles from infected and treated mice (measured in the third week postinfection only), the high K (m) value increased 1.4 times relative to the respective controls. The normal substrate saturation plot of GST in treated mice has a clearly "double sigmoid" character. Our results suggest that despite the complicated character of the GST saturation curve, albendazole seems to act as an allosteric activator for cytosolic GST in infected mouse muscles.

Albendazole↗

[Free-living amoebae as vehicles of pathogenic bacteria].

The free-living amoebae are ubiquitous organisms. They are found in humid soil and all water reservoirs, i.e. fresh, sea, freezing and hot water. They mainly feed on bacteria. Pathogenic properties of amoebae and the mechanisms underlying pathological changes induced during human infection have not yet been fully elucidated. They are the causative agents of primary amoebic meningo-encephalitis (PAM), granulomatous amebic encephalitis (GAE), a chronic progressive disease of the central nervous system, amebic keratitis (AK), a chronic eye infection; amebic pneumitis (AP), a chronic lung infection, and skin infection. Only a few isolates are strongly and permanently pathogenic to humans. Some isolates lose their pathogenic properties after one passage. It has been assumed that such "temporary", unstable pathogenic properties of the amoebae may be caused by internal factors carried by them. It is generally known that the free-living amoebae may be naturally infected with pathogenic bacteria, which have the ability to survive for a long time and to proliferate in the amoebae cells. The role of the amoeba in the process of maintaining, propagating and transmitting human pathogens has not been well recognized. It has been suggested that some infections can be acquired by inhaling aerosols containing amoebae cells filled with bacteria. The presence of bacteria inside the free-living amoebae possess a great challenge to organisations responsible for testing and inspecting the quality and cleanliness of surface waters, swimming pools and drinking water intakes.

Acanthamoeba↗

Changes in the level of antioxidants in the blood from mice infected with Trichinella spiralis.

The biological reaction caused by oxygen-derived free radicals at the molecular and cellular levels involves many different biochemical components which can be directly damaged by oxidizing radicals. As such a reaction may lead to pathological processes, defence mechanisms have evolved to limit the rate of free radical production. These mechanisms employ low-molecular-weight non-enzymatic antioxidants and antioxidant enzymes which are inducible by oxidant stress. In this study, the activity of two antioxidant enzymes, superoxide dismutase (EC 1.15.1.1) and glutathione peroxidase (EC 1.11.1.9), and the level of non-enzymatic antioxidants (total antioxidant status) in the blood from mice infected with Trichinella spiralis was examined. We observed a statistically significant, up to above twofold increase (relative to the control value in uninfected mice) in the level of both enzymes as well as in the total antioxidant status. An intensification of antioxidant processes during trichinellosis could be related to the presence of T. spiralis larvae, which may induce phagocytes to generate free radicals. Our research shows that the maximum growth in antioxidant activity in the blood appears during the period of the greatest muscle damage caused by T. spiralis infection at 3-7 weeks post-infection.

Animals↗

[Amebicidal plants extracts].

The free-living amoebae from genus Acanthamoeba are the causative agents of granulomatous amebic encephalitis (GAE), a chronic progressive disease of the central nervous system; amebic keratitis (AK), a chronic eye infection; amebic pneumitis (AP), a chronic lung infection, and skin infection. Chemotherapy of Acanthamoeba infection is problematic. The majority of infections have been fatal. Only a few cases are reported to have been treated successfully with very highly toxic drugs. The therapy might be succeed, if the diagnosis and therapy is made at very early stage of infection. In our experiments we used the following plant extracts: Solidago virgaurea, Solidago graminifolia, Rubus chamaemorus, Pueraria lobata, and natural plants products as ellagic acid and puerarin. Those therapeutic agents and plants extracts have been tested in vitro for amebicidal or amebostatic activity against pathogenic Acanthamoeba spp. Our results showed that methanol extracts obtained from plants are active against axenic pathogenic Acanthamoeba sp. trophozoites in vitro at concentration below 0.1 mg/ml. Further studies are needed to investigate whether these extracts are also effective in vivo in animal model of infection with Acanthamoeba sp.

Acanthamoeba↗

Effect of nitric oxide releasing drugs on the intensity of infection during experimental trichinellosis in mice.

Nitric oxide (NO) has been shown to play a critical role in various physiological and pathological conditions. Apart from its physiological functions, NO indirectly participates in certain aspects of the pathology of infectious diseases. The aim of this work was to examine the influence of NO-releasing drugs on the intensity of infection in mice infected with Trichinella spiralis. The selected substances were nitroglycerin, isosorbide dinitrate, nitrendipine, sildenafil, and pentaerythritol. These were administered over a prolonged period of time: from the 3rd to the 28th day post-infection. Our study showed that NO administered during trichinellosis may enhance the infection in mice as compared to untreated controls. Thus, treatment with pentaerythritol caused a 44% increase in the intensity of infection relative to the untreated controls, sildenafil a 37% increase, and nitrendipine a 30% increase. This effect may be related to the action of NO on the host's defence mechanisms.

Animals↗

Changes in the activity of glutathione-S-transferase in muscles and sera from mice infected with Trichinella spiralis after treatment with albendazole and levamisole.

In this study, changes in GST activity before and after treatment with antiparasitic drugs were measured in muscles and sera from mice infected with Trichinella spiralis between the 2nd and 9th weeks post-infection (wpi). Levamisole and albendazole, two anthelmintics with a different mode of action, were used. An about twofold stimulation of GST activity in the 2nd wpi and in the later muscular phase (6-7 wpi) was observed in muscles from animals treated with albendazole. In addition, a statistically significant stimulation of GST activity was observed after levamisole treatment, however, only from the 2nd()to the 4th wpi. Neither drugs changed the GST activity in serum. These results suggest that both anthelmintics seem to increase the total activity of GST participating in oxygen free radical-based biochemical defence against Trichinella infection.

Albendazole↗

Effect of exogenous nitric oxide in experimental trichinellosis.

Nitric oxide (NO) is a free radical that has been given much attention over the past few years. It has been nicknamed a "killer" and "mediator" due to its toxic and signaling properties. Apart from its regular physiological function, NO indirectly participates in infectious diseases. Our investigations showed that NO administered as a drug may involve higher histopathological changes in infected animals and can involve higher infection. This report seems to be the first presentation of the participation of NO reactive nitrogen intermediates in the morphological transformation of muscle cells in trichinellosis.

Animals↗