Abstract
Cryptolepine (5-methyl-10H-indolo [3, 2-b] quinoline), an indoloquinoline alkaloid (1) isolated from a medicinal plant traditionally used in Western Africa for treatment of malaria, has been shown to possess broad spectrum biological activity in addition to its antiplasmodial effect. Here, the antileishmanial properties of 11 synthetic derivatives of cryptolepine against Leishmania donovani parasites have been evaluated for the first time. 2,7-Dibromocryptolepine (8; IC50 0.5 ± 0.1 μM) was found to be the most active analogue against the promastigote form of a classical L. donovani strain (AG83) in comparison to the natural alkaloid, cryptolepine (1; IC50 1.6 ± 0.1 μM). Further, 8 was found to substantially inhibit the intracellular amastigote forms of two clinical isolates, one of them being an SbV-resistant strain of L. donovani. Moreover, the toxicity of 8 against normal mouse peritoneal macrophage cells was markedly lower than that of 1 (IC50 values: 9.0 ± 1.2 and 1.1 ± 0.3 μM, respectively), indicating 8 to be a prospective “lead” towards novel antileishmanial therapy. This was supported by studies on the mechanism of cytotoxicity induced by 8 in L. donovani promastigotes (AG83), which revealed the cytoplasmic and nuclear features of metazoan apoptosis. Light microscopic observation demonstrated a gradual decline in the motility, cell volume, and survival of the treated parasites with increasing incubation time. Flow cytometric analysis of phosphatidylserine externalization and distribution of cells in different phases of cell cycle confirmed the presence of a substantial percentage of cells in early apoptotic stage. Disruption of mitochondrial membrane integrity in terms of depolarization of membrane potential, and finally degradation of chromosomal DNA into oligonucleosomal fragments—the hallmark event of apoptosis—characterized the mode of cell death in L. donovani promastigotes.
Similar content being viewed by others
References
Ablordeppey SY, Fan P, Clark AM, Nimrod A (1999) Probing the N-5 region of the indoloquinoline alkaloid, cryptolepine for anticryptoccocal activity. Bioorg Med Chem 7:343–349
Croft SL, Sundar S, Fairlamb AH (2006) Drug resistance in leishmaniasis. Clin Microbiol Rev 19:111–126
Ghosh S, Debnath S, Hazra S, Hartung A, Thomale K, Schultheis M, Kapkova P, Schurigt U, Moll H, Holzgrabe U, Hazra B (2011) Valeriana wallichii root extracts and fractions with activity against Leishmania spp. Parasitol Res 108:861–871
Guimarães LR, Rodrigues AP, Marinho PS, Muller AH, Guilhon GM, Santos LS, do Nascimento JL, Silva EO (2010) Activity of the julocrotine, a glutarimide alkaloid from Croton pullei var. glabrior, on Leishmania (L.) amazonensis. Parasitol Res 107:1075–1081
Hotez PJ, Molyneux DH, Fenwick A, Kumaresan J, Sachs SE, Sachs JD, Savioli L (2007) Control of neglected tropical diseases. N Engl J Med 357:1018–1027
Kumar EV, Etukala JR, Ablordeppey SY (2008) Indolo[3,2-b]quinolines: synthesis, biological evaluation and structure activity-relationships. Mini Rev Med Chem 8:538–554
Lavrado J, Moreira R, Paulo A (2010) Indoloquinolines as scaffolds for drug discovery. Curr Med Chem 17:2348–2370
Lisgarten JN, Coll M, Portugal J, Wright CW, Aymami J (2002) The antimalarial and cytotoxic drug cryptolepine intercalates into DNA at cytosine-cytosine sites. Nat Struct Biol 9:57–60
Maurya R, Mehrotra S, Prajapati VK, Nyle’n S, Sacks D, Sundar S (2010) Evaluation of blood agar microtiter plates for culturing Leishmania parasites to titrate parasite burden in spleen and peripheral blood of patients with visceral leishmaniasis. J Clin Microbiol 48:1932–1934
Modabber F (2010) Leishmaniasis vaccines: past, present and future. Int J Antimicrob Agents 36S:S58–S61
Mosmann T (1983) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods 65:55–63
Mukherjee P, Majee SB, Ghosh S, Hazra B (2009) Apoptosis-like death in Leishmania donovani promastigotes induced by diospyrin and its ethanolamine derivative. Int J Antimicrob Agents 34:596–601
Neal RA, Croft SL (1984) An in-vitro system for determining the activity of compounds against the intracellular amastigote form of Leishmania donovani. J Antimicrob Chemother 14:463–475
Oluwafemi AJ, Okanla EO, Camps P, Munoz-Torrero D, Mackey ZB, Chiang PK, Seville S, Wright CW (2009) Evaluation of cryptolepine and huperzine derivatives as lead compounds towards new agents for the treatment of human African Trypanosomiasis. Nat Prod Commun 4:193–198
Onyeibor O, Croft SL, Dodson HI, Feiz-Haddad M, Kendrick H, Millington NJ, Parapini S, Phillips RM, Seville S, Shnyder SD, Taramelli D, Wright CW (2005) Synthesis of some cryptolepine analogues, assessment of their antimalarial and cytotoxic activities and consideration of their antimalarial mode of action. J Med Chem 48:2701–2709
Perez-Victoria FJ, Sanchez-Canete MP, Seifert K, Croft SL, Sundar S, Castanys S, Gamarro F (2006) Mechanisms of experimental resistance of Leishmania to miltefosine: implications for clinical use. Drug Resist Updat 9:26–39
Santos DO, Coutinho CE, Madeira MF, Bottino CG, Vieira RT, Nascimento SB, Bernardino A, Bourguignon SC, Corte-Real S, Pinho RT, Rodrigues CR, Castro HC (2008) Leishmaniasis treatment—a challenge that remains: a review. Parasitol Res 103:1–10
Seville S (2006) Synthesis of cryptolepine analogues as bio-reducible anticancer agents. Ph.D. thesis, University of Bradford, Bradford, UK
Seville S, Phillips RM, Shnyder SD, Wright CW (2007) Synthesis of cryptolepine analogues as potential bioreducible anticancer agents. Bioorg Med Chem 15:6353–6360
Sharma U, Velpandian T, Sharma P, Singh S (2009) Evaluation of anti-leishmanial activity of selected Indian plants known to have antimicrobial properties. Parasitol Res 105:1287–1293
Shuaibu MN, Pandey K, Wuyep PA, Yanagi T, Hirayama K, Ichinose A, Tanaka T, Kouno I (2008) Castalagin from Anogeissus leiocarpus mediates the killing of Leishmania in vitro. Parasitol Res 103:1333–1338
Srivastava P, Prajapati VK, Vanaerschot M, Auwera GVder, Dujardin GC, Sundar S (2010) Detection of Leptomonas sp. parasites in clinical isolates of Kala-azar patients from India. Inf Gen Evol 10:1145–1150
WHO-TDR news item (2010) http://apps.who.int/tdr/svc/news-events/news/ntd-elimination
Wright CW, Addae-Kyereme J, Breen AG, Brown JE, Cox MF, Croft SL, Gökçek Y, Kendrick H, Phillips RM, Pollet PL (2001) Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agents. J Med Chem 44:3187–3194
Acknowledgments
SH received fellowship support from ICMR, New Delhi (3/1/3/WL/JRF-2008/MPD). SG is a research associate in DAE-BRNS project (2008/37/30/BRNS). SD received fellowship support from DRDO project (DLS/81/48222/LSRB −166/ID/2008). BH acknowledges support from UGC, New Delhi. VKP received fellowship from ICMR, New Delhi, India. This study was partially supported by NIAID, NIH TMRC grant no. 1P50AI074321.
Author information
Authors and Affiliations
Corresponding author
Additional information
Authors Sudipta Hazra and Subhalakshmi Ghosh contributed equally to this work.
Rights and permissions
About this article
Cite this article
Hazra, S., Ghosh, S., Debnath, S. et al. Antileishmanial activity of cryptolepine analogues and apoptotic effects of 2,7-dibromocryptolepine against Leishmania donovani promastigotes. Parasitol Res 111, 195–203 (2012). https://doi.org/10.1007/s00436-012-2818-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00436-012-2818-9