Toxoplasma gondii: Effects of neuwiedase, a metalloproteinase from Bothrops neuwiedi snake venom, on the invasion and replication of human fibroblasts in vitro

Bothrops pirajai snake venom L-amino acid oxidase: in vitro effects on infection of Toxoplasma gondii in human foreskin fibroblasts

“…Therefore, these findings reinforce that the effect of BpirLAAO-I is more likely directed to tachyzoites freshly released from infected lysed cells, with consequent decrease of the infection index of new host cells. Recently, we observed anti-parasitic activity against tachyzoites of T. gondii with another class of snake toxin, a metalloproteinase named neuwiedase purified from Bothrops neuwiedi (Bastos et al, 2008). This enzyme acts by degradating proteins expressed in fibroblast extracellular matrix responsible to maintain adhesion of the cellular monolayer, especially laminin, which is involved in the process of parasite invasion Bastos et al, 2008).…”

“…Recently, we observed anti-parasitic activity against tachyzoites of T. gondii with another class of snake toxin, a metalloproteinase named neuwiedase purified from Bothrops neuwiedi (Bastos et al, 2008). This enzyme acts by degradating proteins expressed in fibroblast extracellular matrix responsible to maintain adhesion of the cellular monolayer, especially laminin, which is involved in the process of parasite invasion Bastos et al, 2008). In this context, BpirLAAO-I can also act in the extracellular matrix by inducing oxidative changes and preventing its use by the parasite as a mediator to access the receptors of laminin found in the membrane of the host cells, thus reducing the infection rates in fibroblasts.…”

“…After 24 h of incubation at 37 o C and 5% CO 2 , cells were washed with phosphate-buffered saline (PBS, pH 7.2), fixed in 10% buffered formalin for 2 h and stained with 1% toluidine blue. Coverslips were mounted on glass slides and cells were examined under light microscope with regards to the infection index (percentage of infected cells per 100 examined cells) and parasite intracellular replication (mean number of parasites per cell in 100 infected cells) (Bastos et al, 2008). Results were also expressed as percentages of inhibition of infection or inhibition of intracellular replication of each treatment in relation to controls (100% of infection).…”

“…Considering that the treatment shows limited efficacy due to their substantial side effects, particularly in immunocompromised individuals and pregnant women, alternative therapies have been investigated by using chemical substances derived from plants, animals and microorganisms, as well as natural toxins and their derivatives (Tempone et al, 2007;Bastos et al, 2008). The aim of this study was to evaluate the effects of BpirLAAO-I on infection of Toxoplasma gondii in human foreskin fibroblasts in vitro.…”

“…For example, L-amino acid oxidases from Bothrops spp were responsible for in vitro killing of Plasmodium falciparum (Zieler et al, 2001), Leishmania spp (Izidoro et al, 2006), and Trypanosoma cruzi (França et al, 2007). Neuwiedase, a metalloproteinase from Bothrops neuwiedi, showed a considerable effect against Toxoplasma gondii infection in vitro (Bastos et al, 2008). T. gondii is a ubiquitous obligate intracellular parasite of the Phylum Apicomplexa and it is unusual within this group due to its capacity to infect a diverse array of cell types and virtually any warm-blooded animal.…”