title: Extracts of Crinum latifolium inhibit the cell viability of mouse lymphoma cell line EL4 and induce activation of anti-tumour activity of macrophages in vitro.
abstract: BACKGROUND
  Crinum latifolium L. (CL) leaf extracts have been traditionally used in Vietnam and are now used all over the world for the treatment of prostate cancer. However, the precise cellular mechanisms of the action of CL extracts remain unclear.
  
  
  OBJECTIVE
  To examine the effects of CL samples on the anti-tumour activity of peritoneal murine macrophages.
  
  
  METHODS
  The properties of three extracts (aqueous, flavonoid, alkaloid), one fraction (alkaloid), and one pure compound (6-hydroxycrinamidine) obtained from CL, were studied (i) for redox capacities (DPPH and bleaching beta-carotene assays), (ii) on murine peritoneal macrophages (MTT assay) and on lymphoma EL4-luc2 cells (luciferine assay) for cytotoxicity, (iii) on macrophage polarization (production of ROS and gene expression by PCR), and (iv) on the tumoricidal functions of murine peritoneal macrophages (lymphoma cytotoxicity by co-culture with syngeneic macrophages).
  
  
  RESULTS
  The total flavonoid extract with a high antioxidant activity (IC50=107.36 mg/L, DPPH assay) showed an inhibitory action on cancer cells. Alkaloid extracts inhibited the proliferation of lymphoma cells either by directly acting on tumour cells or by activating of the tumoricidal functions of syngeneic macrophages. The aqueous extract induced mRNA expression of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin 6 (IL-6) indicating differentiation of macrophages into pro-inflammatory M1 polarized macrophages. The total flavonoid, alkaloid extracts and an alkaloid fraction induced the expression of the formyl peptide receptor (FPR) on the surface of the polarized macrophages that could lead to the activation of macrophages towards the M1 phenotype. Aqueous and flavonoid extracts enhanced NADPH quinine oxido-reductase 1 (NQO1) mRNA expression in polarized macrophages which could play an important role in cancer chemoprevention. All the samples studied were non-toxic to normal living cells and the pure alkaloid tested, 6-hydroxycrinamidine, was not active in any of the models investigated.
  
  
  CONCLUSIONS
  Our results indicate that CL extracts and alkaloid fraction (but not pure 6-hydroxycrinamidine) inhibit the proliferation of lymphoma cells in multiple pathways. Our results are in accordance with traditional usage and encourage further studies and in vivo assays.
authors.affiliation: University of Medicine and Pharmacy of Ho Chi Minh City, 41 Dinh Tien Hoang street, District 1, Ho Chi Minh City, Vietnam.
authors.forename: Hoang-Yen T
authors.initials: HY
authors.lastname: Nguyen
authors.forename: Bach-Hue T
authors.initials: BH
authors.lastname: Vo
authors.forename: Lac-Thuy H
authors.initials: LT
authors.lastname: Nguyen
authors.forename: Jose
authors.initials: J
authors.lastname: Bernad
authors.forename: Mohamad
authors.initials: M
authors.lastname: Alaeddine
authors.forename: Agnes
authors.initials: A
authors.lastname: Coste
authors.forename: Karine
authors.initials: K
authors.lastname: Reybier
authors.forename: Bernard
authors.initials: B
authors.lastname: Pipy
authors.forename: Françoise
authors.initials: F
authors.lastname: Nepveu
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D018920:Coculture Techniques; D031407:Crinum / Q000737:chemistry* / Q000254:growth & development; D020834:Ethnopharmacology; D006801:Humans; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008518:Medicine, East Asian Traditional; D051379:Mice; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D014744:Vietnam
chemical_list: D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D017382:Reactive Oxygen Species
keywords: 2,2-diphenyl-1-picrylhydrazyl; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; CL; Crinum latifolium; Crinum latifolium L; DPPH; Immunomodulation; M1; MTT; Macrophages; PBMC; PCR; ROS; Radical scavenger; classically activated macrophages; peripheral blood mononuclear cells; polymerase chain reaction; reactive oxygen species