Asiaticoside induces tumour-necrosis-factor--mediated nitric oxide production to cure experimental visceral leishmaniasis caused by antimony-susceptible and -resistant Leishmania donovani strains

作者：Bhaumik Siddhartha Kumar; Paul Joydeep; Naskar Kshudiram; Karmakar Subir; De Tripti^*

来源：Journal of Antimicrobial Chemotherapy, 2012, 67(4): 910-920.

DOI：10.1093/jac/dkr575

• antileishmanial drugs
• macrophage function
• T cell response
• cluster of differentiation 14

The aim of this study was to investigate and characterize the efficacy of asiaticoside in an experimental model of visceral leishmaniasis caused by antimony-susceptible (AG83) and -resistant (GE1F8R and K39) Leishmania donovani.
The effect of asiaticoside was evaluated by microscopic counting of intracellular amastigotes in cultured macrophages stained with Giemsa. The antileishmanial effect of the compounds was assessed in infected BALB/c mice by estimation of splenic and liver parasite burdens in Leishman Donovan units. Cytokines were measured by real-time PCR and ELISA. Intracellular tumour necrosis factor- (TNF-) was measured by fluorescence-activated cell sorting. Nitric oxide was measured by the Griess reaction.
Besides effectively inhibiting in vitro replication of the parasite within macrophages, asiaticoside treatment resulted in almost complete clearance of the liver and splenic parasite burden when administered at a dose of 5 mg/kg10 starting on day 30 of challenge with antimony-susceptible (AG83) and -resistant (GE1F8R and K39) L. donovani. Asiaticoside treatment was associated with a switch in the host from a Th2- to a Th1-type immune response accompanied by the induction of TNF--mediated nitric oxide production, all of which are important elements for macrophage function in antileishmanial defence mechanisms.
These results suggest that oral therapy with asiaticoside shows promising antileishmanial efficacy in animals infected by antimony-susceptible (AG83) and -resistant (GE1F8R and K39) L. donovani.

• 出版日期2012-4