In vitro antiparasitic activity of microbial pigments and their combination with phytosynthesized metal nanoparticles

Inorganic nanoparticles kill <em>Toxoplasma gondii</em> via changes in redox status and mitochondrial membrane potential

“…The NPs significantly reduced the parasite viability by .90% (Figure 1) with EC 50 values of #7, #1, and #100 µg/mL for AuNPs, AgNPs, and PtNPs, respectively (Table 1). AuNPs and AgNPs showed a stronger anti-T. gondii activity relative to that of PtNPs, consistent with other studies, [14][15][16][17] that have reported antimicrobial and/or antiparasitic properties of AuNPs and AgNPs; similar studies using PtNPs were scarce in the literature. A reference drug (sulfadiazine, used to treat active toxoplasmosis), which was included as a positive control, decreased the parasite viability by .95%.…”

“…12 In addition, NPs could be accumulated in tissues, 13 thereby presenting a formidable platform to target T. gondii cysts in host tissues. Of special interest are the metal NPs such as gold and silver, which have antimicrobial activity, 14,15 antiparasitic activity, 16,17 and other bioactivities, including the selective inhibition of some enzyme activities. 9,[18][19][20][21] The versatility of metal NPs 10 makes them an attractive choice to be explored further as antiparasitic agents, particularly against toxoplasmosis.…”

Advances in Chromobacterium violaceum and properties of violacein-Its main secondary metabolite: A review

“…Furthermore, violacein showed weak cytotoxicity to blood mononuclear cells and to HeLa cervical and MCF7 breast cancer cell lines, with IC 50 values ranging from 98 to 158 μg/mL. Again, the presence of the nanoparticles did not affect cytotoxicity, supporting the safety of the compound (Rahul et al, 2015). This is the first time the violacein was reported to act against T. brucei gambiense.…”

“…In addition to its antileishmanial activity (Leon et al, 2001), trypanocidal activity was reported against Trypanosoma cruzi (Durán et al, 2007), as well as antimicrobial activity of violacein-containing nanoparticles (Martins et al, 2010). In the study conducted by Rahul et al (2015), the authors demonstrated that violacein shows low toxicity to Trypanosoma brucei gambiense bloodstream forms in vitro, with an IC 50 value of 3.9 μg/mL, which was not altered when combined with SNPs or GNPs. Violacein and its combinations also inhibited P. falciparum similarly, with IC 50 values around 52 μg/mL.…”

“…Considering these results and its low toxicity in mice (Bromberg et al, 2010), it is conceivable to foresee the development of this indole derivative as an antiparasitic compound itself or to stimulate research based on the discovery of secondary metabolites from natural sources. In this respect, Rahul et al (2015) tested the activity of violacein isolated from C. violaceum in combination with phytosynthesized silver (SNPs) and gold nanoparticles (GNPs) against two important neglected human diseases caused by parasitic protozoa, malaria and African trypanosomiasis.…”