Anti-irritative effect of methylrosaniline chloride (Gentian violet)

Transmission-blocking compound candidates against Plasmodium vivax using P. berghei as an initial screening

BACKGROUND

Different strategies for improvement of malaria control and elimination are based on the blockage of malaria parasite transmission to the mosquito vector. These strategies include the drugs that target the plasmodial sexual stages in humans and the early developmental stages inside mosquitoes.

OBJECTIVES

Here we tested Malaria Box compounds in order to evaluate their activity against male and female gametocytes in Plasmodium berghei, mosquito infection in P. vivax and ookinete formation in both species.

METHODS/FINDINGS

The membrane feeding assay and the development of ookinetes by a 24 h ex vivo culture and the ookinete yield per 1000 erythrocytes were used to test transmission-blocking potential of the Malaria Box compounds in P. vivax. For P. berghei we used flow cytometry to evaluate male and female gametocyte time course and fluorescence microscopy to check the ookinete development. The two species used in this study showed similar results concerning the compounds’ activity against gametocytes and ookinetes, which were different from those in P. falciparum. In addition, from the eight Malaria Box compounds tested in both species, compounds MMV665830, MMV665878 and MMV665941 were selected as a hit compounds due the high inhibition observed.

CONCLUSION

Our results showed that P. berghei is suitable as an initial screening system to test compounds against P. vivax.

Discovering the in vitro potent inhibitors against Babesia and Theileria parasites by repurposing the Malaria Box: A review

There is an innovative approach to discovering and developing novel potent and safe anti-Babesia and anti-Theileria agents for the control of animal piroplasmosis. Large-scale screening of 400 compounds from a Malaria Box (a treasure trove of 400 diverse compounds with antimalarial activity has been established by Medicines for Malaria Venture) against the in vitro growth of bovine Babesia and equine Babesia and Theileria parasites was performed, and the data were published in a brief with complete dataset from 236 screens of the Malaria Box compounds. Therefore, in this review, we explored and discussed in detail the in vitro inhibitory effects of 400 antimalarial compounds (200 drug-like and 200 probe-like) from the Malaria Box against Babesia (B.) bovis, B. bigemina, B. caballi, and Theileria (T.) equi. Seventeen hits were the most interesting with regard to bovine Babesia parasites, with mean selectivity indices (SIs) greater than 300 and half maximal inhibitory concentration (IC₅₀s) ranging from 50 to 410 nM. The most interesting compounds with regard to equine Babesia and Theileria parasites were MMV020490 and MMV020275, with mean SIs > 258.68 and >251.55, respectively, and IC₅₀s ranging from 76 to 480 nM. Ten novel anti-B. bovis, anti-B. bigemina, anti-T. equi, and anti-B. caballi hits, MMV666093, MMV396794, MMV006706, MMV665941, MMV085203, MMV396693, MMV006787, MMV073843, MMV007092, and MMV665875, with nanomole levels of IC₅₀ were identified. The most interesting hits were MMV396693, MMV073843, MMV666093, and MMV665875, with mean SIs greater than 307.8 and IC₅₀s ranging from 43 to 630 nM for both bovine Babesia and equine Babesia and Theileria parasites. Screening the Malaria Box against the in vitro growth of Babesia and Theileria parasites helped with the discovery of new drugs than those traditionally used, diminazene aceturate and imidocarb dipropionate, and indicated the potential of the Malaria Box in finding new, potent antibabesial drugs.

New Treatment for Percutaneous Sites in Patients with a Ventricular Assist Device: Nihon University Crystal Violet Method

BACKGROUND

Infection of the percutaneous site of a ventricular assist device (VAD) is a challenging complication. We report our experience with crystal violet Solbase (Nihon University crystal violet method) for prevention of driveline or cannula infections in VAD patients.

PATIENTS AND METHODS

The crystal violet method was used in 10 patients (prophylaxis in nine and treatment in one). Eight patients had an extracorporeal VAD (Nipro) and two had an implantable VAD (Heart Mate II).

RESULTS

The infection-free period was 4-623 days (mean: 144.2 ± 222.9 days). All eight patients with an extracorporeal VAD died, while the two patients with an implantable VAD (Heart Mate II) survived. Infection was improved in a patient with MRSA, and the results of bacteriological examination were always negative in the patients receiving prophylaxis. The two patients with an implantable VAD had no infection for 2 and 20 months after implantation.

CONCLUSION

These findings suggest that the Nihon University crystal violet method is effective for prevention and treatment of driveline or cannula infections in patients with a VAD.