Potent in vitro antileishmanial activity of a nanoformulation of cisplatin with carbon nanotubes against Leishmania major

OBJECTIVES

The aim of this study was to evaluate the cytotoxicity and antileishmanial activity of cisplatin-bonded carbon nanotubes both against promastigotes and amastigotes of Leishmania major in vitro.

METHODS

Cisplatin-bonded single-walled carbon nanotubes (CP-SWCNT) and cisplatin-bonded multi-walled carbon nanotubes (CP-MWCNT) were considered as test compounds. In addition, SWCNT, MWCNT, free cisplatin and meglumine antimoniate (Glucantime^®) were considered as controls. The effect of each compound was evaluated both on promastigote and amastigote stages of L. major and the results were compared.

RESULTS

There was a statistically significant difference between the half-maximal inhibitory concentration (IC₅₀) of CP-SWCNT and each of the controls, including SWCNT, cisplatin and Glucantime^® (P<0.05). In addition, IC₅₀ values of CP-MWCNT and each of the controls, including MWCNT, cisplatin and Glucantime^®, were significantly different both for promastigotes and amastigotes (P<0.05). However, the selectivity index (SI) of CP-SWCNT was <10 (5.23), indicating that this compound is not completely safe. Moreover, the SI values of CP-MWCNT (12.54) and Glucantime^® (16.28) were >10, indicating the selective effect of these two compounds on the parasite. Moreover, the IC₅₀ of CP-MWCNT (0.11±0.09μM) for amastigotes was 41-fold lower than that of Glucantime^® (4.52±1.31μM), suggesting that a lower dose of CP-MWCNT in comparison with Glucantime^® is required to kill 50% of amastigotes.

CONCLUSIONS

According to the potent in vitro antileishmanial activity of CP-MWCNT at low concentration against L. major, we suggest that they are evaluated in an animal model.