title: Supplementation of host response by targeting nitric oxide to the macrophage cytosol is efficacious in the hamster model of visceral leishmaniasis and adds to efficacy of amphotericin B.
abstract: We investigated efficacy of nitric oxide (NO) against Leishmania donovani. NO is a mediator of host response to infection, with direct parasiticidal activity in addition to its role in signalling to evoke innate macrophage responses. However, it is short-lived and volatile, and is therefore difficult to introduce into infected cells and maintain inracellular concentrations for meaningful periods of time. We incorporated diethylenetriamine NO adduct (DETA/NO), a prodrug, into poly(lactide-co-glycolide) particles of ∼200 nm, with or without amphotericin B (AMB). These particles sustained NO levels in mouse macrophage culture supernatants, generating an area under curve (AUC0.08-24h) of 591.2 ± 95.1 mM × h. Free DETA/NO resulted in NO peaking at 3 h and declining rapidly to yield an AUC of 462.5 ± 193.4. Particles containing AMB and DETA/NO were able to kill ∼98% of promastigotes and ∼76% of amastigotes in 12 h when tested in vitro. Promastigotes and amastigotes were killed less efficiently by particles containing a single drug- either DETA/NO (∼42%, 35%) or AMB (∼90%, 50%) alone, or by equivalent concentrations of drugs in solution. In a pre-clinical efficacy study of power >0.95 in the hamster model, DETA/NO particles were non-inferior to Fungizone® but not Ambisome®, resulting in significant (∼73%) reduction in spleen parasites in 7 days. Particles containing both DETA/NO and AMB were superior (∼93% reduction) to Ambisome®. We conclude that NO delivered to the cytosol of macrophages infected with Leishmania possesses intrinsic activity and adds significantly to the efficacy of AMB.
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India; Academy of Scientific & Innovative Research (AcSIR), Anusandhan Bhawan, Rafi Marg, New Delhi 110001, India.
authors.forename: Sanketkumar
authors.initials: S
authors.lastname: Pandya
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India.
authors.forename: Rahul Kumar
authors.initials: RK
authors.lastname: Verma
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Khare
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India.
authors.forename: Brajendra
authors.initials: B
authors.lastname: Tiwari
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India; National Institute of Pharmaceutical Education and Research, ITI Compound, Rae Bareli 229010, UP, India.
authors.forename: Dadi A
authors.initials: DA
authors.lastname: Srinivasarao
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Dube
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India.
authors.forename: Neena
authors.initials: N
authors.lastname: Goyal
authors.affiliation: CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow 226031, UP, India. Electronic address: amit_misra@cdri.res.in.
authors.forename: Amit
authors.initials: A
authors.lastname: Misra
mesh_terms: D000666:Amphotericin B / Q000008:administration & dosage*; D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage*; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D007893:Leishmania donovani / Q000187:drug effects* / Q000502:physiology; D007898:Leishmaniasis, Visceral / Q000188:drug therapy*; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D053758:Nanoparticles / Q000008:administration & dosage; D009603:Nitroso Compounds / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000981:Antiprotozoal Agents; D009603:Nitroso Compounds; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D000666:Amphotericin B
keywords: Amastigotes; Amphotericin B; Leishmania donovani; Nitric oxide donor; PLGA; Promastigotes