title: Protective effect of Croton caudatus Geisel leaf extract against experimental visceral leishmaniasis induces proinflammatory cytokines in vitro and in vivo.
abstract: In the present state of overwhelming emergence of drug-unresponsive phenotypes of Leishmania donovani and persistent severe toxicity in conventional anti-leishmanial therapy, in search for novel leads, the aim of this study has been fixed to identify the active extract(s) of Croton caudatus Geisel. var. tomentosus Hook effective against the parasitic protozoans in vitro and in vivo. C. caudatus Geisel. is often used by Chakma and Hmar community, the local tribes of north-east India for medicinal and veterinary purposes. Among the five semi-purified extracts tested, C. caudatus leaves, extracted in hexane and subsequently semi-purified in a column packed with silica gel (70-130 µM; mesh size 60 A°) using ethyl acetate-hexane solvent (9:1), was found to be the most effective growth inhibitor (JDHex) against the Leishmania promastigotes and amastigotes. JDHex significantly altered the biochemical parameters (protein, lipid and carbohydrates) in promastigotes followed by the morphological changes, DNA condensation and subsequent apoptosis in L. donovani. In consequent steps, it has been also proved that JDHex reduced the replication of intracellular amastigotes with concomitant release of nitric oxide and pro-inflammatory cytokines, IL-12 and TNF-α in vitro. Significantly, the 50% inhibitory concentration of JDHex was estimated much lower against the intracellular amastigotes (2.5 µg/mL) in comparison to promastigotes (10 µg/mL). JDHex was also found efficient in reducing parasite burden in spleen and liver when treated in vivo and increased the intracellular IFN-γ and decreased the IL-10 in CD4+ T cells in splenocytes of orally treated animals. The results of this study support the importance in exploration of novel anti-leishmanial leads from C. caudatus Geisel. var. tomentosus Hook. against the L. donovani (MHOM/IN/83/AG83) infection. Partial chemical characterization of JDHex revealed the presence of terpenoids. However, the further chemical investigation of JDHex is warranted.
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Somaditya
authors: S
authors: Dey
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Debarati
authors: D
authors: Mukherjee
authors: Wildlife Biology and Natural Product Research Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Sondipon
authors: S
authors: Chakraborty
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Suvadip
authors: S
authors: Mallick
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Aritri
authors: A
authors: Dutta
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Joydip
authors: J
authors: Ghosh
authors: Department of Chemistry, Skula Womens' College, Namol, Manipur, India.
authors: Ningombam
authors: N
authors: Swapana
authors: University of Calcutta 35, Ballygunge Circular Road, Kolkata, West Bengal, India.
authors: Swatilekha
authors: S
authors: Maiti
authors: Wildlife Biology and Natural Product Research Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India.
authors: Narayan
authors: N
authors: Ghorai
authors: Institute of Bioresource and Sustainable Development (IBSD), Imphal, Manipur, India.
authors: Chingakham Brajakishor
authors: CB
authors: Singh
authors: Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, West Bengal, India. Electronic address: cpcu.immunology@gmail.com.
authors: Chiranjib
authors: C
authors: Pal
mesh_terms: D000818:Animals; D017209:Apoptosis; D029802:Croton / Q000737:chemistry*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D020128:Inhibitory Concentration 50; D007893:Leishmania donovani / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D007898:Leishmaniasis, Visceral / Q000188:drug therapy / Q000276:immunology / Q000517:prevention & control*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000469:parasitology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D009569:Nitric Oxide / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves / Q000737:chemistry; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D016207:Cytokines; D010718:Phosphatidylserines; D010936:Plant Extracts; D009569:Nitric Oxide
keywords: Anti-leishmanial leads; Croton caudatus; IFN-γ; Leishmania donovani; Nitric oxide; Pro-inflammatory cytokines