Ameliorating effects of Nigella sativa oil on aggravation of inflammation, oxidative stress and cytotoxicity induced by smokeless tobacco extract in an allergic asthma model in Wistar rats

BACKGROUND: The comparison of smokeless tobacco (ST) exposure versus Ovalbumin (Ova) sensitized rats or asthmatic patients has hardly been studied in the literature. Thus, the present study aims to investigate the aggravation of inflammation, exacerbation of asthma, oxidative stress and cytotoxicity induced by ST. METHODS: ST was given at the dose of 40 mg/kg in an allergic asthma model in Wistar rats. Furthermore, the effects of oral administration of Nigella sativa oil (NSO), at a dose of 4 mL/kg/day, were investigated. RESULTS: The obtained results showed that ST clearly enhanced lung inflammation through interleukin-4 (IL-4) and Nitric oxide (NO) increased production. Actually, ST was found to intensify the oxidative stress state induced by Ova-challenge in rats, which was proven not only by augmenting lipid peroxidation and protein oxidation, but also by altering the non-enzymatic and enzymatic antioxidant status. Furthermore, the aggravation of inflammation and oxidative stress was obviously demonstrated by the histopathological changes observed in lung. In contrast, NSO administration has shown anti-inflammatory effects by reducing IL-4 and NO production, restoring the antioxidant status, reducing lipid peroxidation and improving the histopathological alterations by both protein oxidation and NSO treatment. CONCLUSIONS: Our data have proven that severe concurrent exposure to allergen and ST increases airway inflammation and oxidative stress in previously sensitized rats. They also suggest that the oral NSO treatment could be a promising treatment for asthma

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Ameliorating effects of Nigella sativa oil on aggravation of inflammation, oxidative stress and cytotoxicity induced by smokeless tobacco extract in an allergic asthma model in Wistar rats.

BACKGROUND: The comparison of smokeless tobacco (ST) exposure versus Ovalbumin (Ova) sensitized rats or asthmatic patients has hardly been studied in the literature. Thus, the present study aims to investigate the aggravation of inflammation, exacerbation of asthma, oxidative stress and cytotoxicity induced by ST. METHODS: ST was given at the dose of 40mg/kg in an allergic asthma model in Wistar rats. Furthermore, the effects of oral administration of Nigella sativa oil (NSO), at a dose of 4mL/kg/day, were investigated. RESULTS: The obtained results showed that ST clearly enhanced lung inflammation through interleukin-4 (IL-4) and Nitric oxide (NO) increased production. Actually, ST was found to intensify the oxidative stress state induced by Ova-challenge in rats, which was proven not only by augmenting lipid peroxidation and protein oxidation, but also by altering the non-enzymatic and enzymatic antioxidant status. Furthermore, the aggravation of inflammation and oxidative stress was obviously demonstrated by the histopathological changes observed in lung. In contrast, NSO administration has shown anti-inflammatory effects by reducing IL-4 and NO production, restoring the antioxidant status, reducing lipid peroxidation and improving the histopathological alterations by both protein oxidation and NSO treatment. CONCLUSIONS: Our data have proven that severe concurrent exposure to allergen and ST increases airway inflammation and oxidative stress in previously sensitized rats. They also suggest that the oral NSO treatment could be a promising treatment for asthma.

Comparative toxicity of three ecdysone agonist insecticides against the Mediterranean flour moth.

The Mediterranean flour moth, Ephestia Kuehniella Zeller (Lepidoptera: Pyralidae), is an important pest in stored products worldwide, and is one of the major pests in flour mills in Algeria. Because environmental consideration, alternative approaches to neurotoxic insecticides, as well as safe, effective, and sound integrated pest management strategies are developed pest control agents such as the insect growth regulator (IGRs). Among these IGRs, the bisacylhydrazine derivatives are nonsteroidal ecdysterold agonists that mimic the action of moulting hormones and induce a precocious and incomplete moult in several insect orders. In topical bioassays using the pupae of E. kuehniella, three ecdysteroid agonists: RH-5849, the first bisaclhydrazine ecdysone agonist and two analogs, RH-5992 (tebufenozide) and RH-0345 (halofenozide), were evaluated on the reproduction under laboratory conditions. In a first series of experiments, the efficacy of these compounds was tested. These compounds exhibited insecticidal activity and the duration of pupal development was reduced with a dose-response relationship. Among the three tested compounds, tebufenozide (LD50 = 0.005 microg) appeared the most potent ecdysteroid agonist against E. kuehniella (RH-5849: LD50 = 0.05 microg and RH-0345: LD50 = 5.10 microg). In a second series of experiments, the effects of the ecdysone agonists (LD50) were investigated on the reproduction. Data showed that the three compounds affected growth of ovaries as evidenced by morphometric measurements of the ovaries from newly emerged adult females. In addition, the thickness of the chorion from basal oocytes was reduced only by RH-5992 and RH-0345. However, electron microscopic observations revealed that the three compounds had no significant effect on the fine structure of chorion. Finally, measurements of ovarian ecdysteroids' production by an enzyme immunoassay showed an increase in the hormonal amounts recorded in treated series compared to control series.

Effects of flucycloxuron, a chitin synthesis inhibitor, on reproductive events and thickness of chorion in mealworms.

Flucycloxuron (FCX), a benzoylphenylurea derivative, was evaluated on Tenebrio molitor. The compound was incorporated into the diet and administrated to newly emerged females at various doses (2, 5 and 10 mg/kg). FCX was found to affect several reproductive events such as the duration of preovipostion and oviposition period, the fecundity, the viability of eggs and the duration of embryonic development, respectively. Morphological study of ovaries showed that FCX reduced both oocytes number, the ovaries weight and the size and the volume of the basal oocyte during the sexual maturation. In addition, it reduced the thickness of chorion from freshly laid eggs. However, electron microscopic study revealed that this compound had no significant effect on the fine structure of chorion. Finally, measurements of ovarian ecdysteroids production by an enzyme immunoassay indicated a reduction in the hormonal amounts recorded.

RH-0345 restored partly the effects induced by KK-42 on reproductive events in mealworms.

In the mealworm, Tenebrio molitor L., KK-42, an imidazole derivative, was found to reduce ovarian ecdysteroid production, while RH-0345, a benzoylhydrazine analogue, has been reported to affect growth and development of mealworm ovaries in a manner similar to 20-hydroxyecdysone. In order to determine whether the reduction of reproduction events is dependent on inhibition of ecdysteroid production by ovaries, RH-0345 (10 micrograms/insect) was applied before or after topical application of KK-42 (10 micrograms/insect) on newly emerged adult females. KK-42 applied alone increased significantly the pre-oviposition period compared to controls. It also significantly delayed egg-laying compared to combined treatments using KK-42 before or after RH-0345. KK-42 applied alone or with and before RH-0345, was found to reduce significantly the duration of oviposition period. Moreover, there was a significant difference in the duration of oviposition period between the two combined treatments. The fecundity was significantly reduced in all treated series compared to controls. In addition, the fecundity recorded in treated series by RH-0345 alone or before KK-42 was significantly higher than in KK-42 treated series. Lastly, the viability of eggs laid was significantly reduced in all treated series compared to controls. Moreover, the combined treatment pronounced the reduction in egg viability. Free ecdysteroids (ecdysone and 20-hydroxyecdysone) in eggs of control and RH-0345 treated females were analyzed by an enzymo-immunoassay using two specific antibodies.

Characterization of cryoglobulins by immunoblotting.

We adapted an immunoblotting technique for the immunochemical characterization of cryoglobulins. We first compared the results from 157 samples with results obtained by immunofixation and immunoelectrophoresis and then with clinical observations in 125 cases. Full identification was possible in 98% of the cases by immunoblotting, in 54% by immunofixation, and in 28% by immunoelectrophoresis. Novel microheterogeneity aspects were observed by immunoblotting and immunofixation in 13% and 6% of the cases studied, respectively. Our results confirm the frequency of autoimmune and infectious diseases associated with mixed cryoglobulinemias, whereas a lymphoproliferative syndrome was observed only in cases of cryoglobulinemia with a monoclonal constituent or a microheterogeneity aspect, which was not always revealed by immunofixation or immunoelectrophoresis. The pathophysiological importance and classification of microheterogeneity aspects is not clear. These observations justify using a sensitive and specific method for identifying cryoglobulins, even when present at low concentrations, and call for long-term studies of these patients.