Antiparasitic effect of Dinoponera quadriceps giant ant venom.

Neglected tropical diseases (NTD) are treated with toxic therapy of limited efficacy. Previously, we studied the antimicrobial effect of Dinoponera quadriceps venom (DqV) against bacteria. To continue the study, we report in this short communication the antimicrobial effect of DqV against Leishmania amazonensis and Trypanosoma cruzi. DqV inhibits the promastigote forms of L. amazonensis and all T. cruzi developmental forms, with low toxicity in host cells. DqV causes cell death in T. cruzi through necrotic and apoptotic mechanisms observed by staining the cells with annexin V-FITC (AX) and propidium iodide (PI), loss of mitochondrial membrane potential by flow cytometry analyses and confocal microscopy and morphological alterations, such as loss of membrane integrity and cell shrinkage by scanning electron microscopy (SEM). In conclusion, we suggest there is an antimicrobial effect also on parasites.

Novel Pharmacological Properties of Dinoponera quadriceps Giant Ant Venom.

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.

The effects of the Brazilian ant Dinoponera quadriceps venom on chemically induced seizure models.

Arthropod venoms are potential sources of neuroactive substances, providing new tools for the design of drugs. The aim of this study was to evaluate the effects of Dinoponera quadriceps venom (DqV) on seizure models in mice induced by pentylenetetrazole (PTZ), pilocarpine, and strychnine. In the PTZ model, intraperitoneal treatment with DqV (0.5mg/kg) increased the time until the first seizure and the percentage of survival (155.4±27.7s/12.5%, p<0.05) compared to the control group (79.75±3.97s/0%), whereas endovenous treatment (0.1 and 0.5mg/kg) decreased the time until the first seizure (0.1mg/kg: 77.83±5.3s versus 101.0±3.3s in the control group; 0.5mg/kg: 74.43±3.9s versus 101.0±3.3s for the control group, p<0.05). We did not observe significant changes in the pilocarpine- and strychnine-induced seizure models. In assays that measured oxidative parameters in the PTZ model, intraperitoneal treatment with DqV (0.5 and 2.0mg/kg) only decreased the levels of MDA and nitrite in the cortex. However, endovenous treatment with DqV (0.1 and 0.5mg/kg) increased the levels of MDA in the cortex and hippocampus and at a dose of 0.5mg/kg in the striatum. Moreover, increased in nitrite content was observed in all three of the brain regions analyzed. Taken together, the D. quadriceps venom caused both neuroprotective and neurotoxic effects in a PTZ-induced seizure model, and this effect was dependent on the route of administration used.