This study aimed at evaluating the antidepressant-like action of the marine alga Solieria filiformis lectin (SfL) and to investigate the participation of the monoaminergic system in this action. For this, male Swiss mice (n=10) were pretreated with intravenous injections (i.v.) of SfL (1, 3 or 9mg/kg) and submitted to open field (OFT), tail suspension (TST), forced swimming (FST), elevated plus-maze (EPMT) and hole-board tests (HBT). As controls, mice received sterile saline (i.v.), imipramine (10 or 30mg/kg; intraperitoneally - i.p.) or diazepam (1 mk/kg; i.p.). To assess the involvement of the monoaminergic system in SfL effects, the FST was conducted in mice pretreated with PCPA, an inhibitor of serotonin synthesis, or noradrenergic and dopaminergic receptors specific antagonists. The results showed that SfL has an antidepressant-like effect, with no psychostimulant and anxiolytic-like effects. When denatured or combined with mannan, SfL lost the ability to reduce the immobility time in the FST. In addition, SfL antidepressant-like effect was inhibited by the pretreatment of mice with SCH 23390, a dopamine D receptor antagonist, and by sulpiride, a dopamine D receptor antagonist. Thus, SfL produced an antidepressant-like effect, which is probably dependent on its interaction with the dopaminergic system.
Oxidative stress (OS) has been related to cocaine's actions and also to numerous nervous system pathologies, including seizures. The purpose of this work was to determine the alterations in glutathione (GSH) content, nitrite/nitrate and MDA levels after cocaine-induced toxicity. Male Swiss mice were injected (i.p.) with cocaine 90 mg/kg and observed during 1h. After this cocaine overdose some animals presented status epilepticus (SE) while some died after seizures. These animals were divided in two groups, SE and death. A group with an association of the antioxidant Vitamin E (Vit E, 400mg/kg, i.p.) plus Coc 90 (Vit E plus Coc 90) was undertaken to assess the neuroprotective effect of Vit E. Neurochemical analyses were carried out in prefrontal cortex (PFC) and striatum (ST). GSH levels increased only after cocaine-induced death in both areas studied. Cocaine-induced SE has increased nitrite/nitrate content in PFC and ST, while after death the increase was only in PFC. MDA (the lipid peroxidation marker) was elevated after SE and death in ST and only after death in PFC. Antioxidant treatment significantly reduced the GSH, nitrite/nitrate in ST and MDA levels. Only nitrite/nitrate content in PFC has not been decreased by Vit E pretreatment. The results relate that oxidative stress occurs after cocaine-induced toxicity mainly after death indicating that probably the increase of OS in the animal's brain leads to seizures and death, also showing a protective effect of Vit E in this process. Together with previous results this study contributes to the knowledge of cocaine-induced toxicity and possible in the near future to the use of antioxidants in the prevention of cocaine-induced CNS toxicity.
The South American giant ant, Dinoponera quadriceps (Hymenoptera, Formicidae, Ponerinae), produces proteinaceous venom that has antinociceptive, neuroprotective and antimicrobial effects, thereby supporting the popular use of these ants to treat asthma, rheumatism, earache and back pain. Anticoagulant activity is another biological property that has been shown for the venom of other hymenopteran species, like wasps. The aim of this study was to assess the anti-inflammatory, anticoagulant and antiplatelet properties of D. quadriceps venom (DqV). DqV anti-inflammatory activity was assessed by intravenous administration in Swiss mice in the models of paw edema and peritonitis. In vitro, DqV was assessed in coagulation (activated partial thromboplastin time) and platelet aggregation tests. DqV inhibited (27–33%) the edema elicited by carrageenan and the leucocyte migration (43%) elicited by zymosan. DqV decreased by 57% and 42%, respectively, the content of malondialdehyde and nitrite in the peritoneal fluid. DqV prolonged (1.8x) the clotting time and decreased (27%) the platelet aggregation induced by adenosine diphosphate. The crude venom of D. quadriceps presents an anti-inflammatory effect in mice and in vitro anticoagulant and antiplatelet effects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.