title: Evaluation of antiangiogenic and antiproliferative potential of the organic extract of green algae Chlorella pyrenoidosa.
abstract: OBJECTIVE
  algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to evaluate the antiangiogenic and antiproliferative activity of Chlorella pyrenoidosa in experimental models of angiogenesis and by MTT assay.
  
  
  METHODS
  lyophilized extract of C. pyrenoidosa was extracted using dichloromethane/methanol (2:1), concentrated and vacuum evaporated to obtain the dried extract. The crude extract was evaluated in the vascular endothelial growth factor (VEGF)-induced angiogenesis in in ovo chick chorioallantoic membrane assay (CAM) at various concentrations (n = 8) using thalidomide and normal saline as positive and untreated control groups, respectively. The crude extract was also subjected to the antiangiogenic activity in the silver nitrate/potassium nitrate cautery model of corneal neovascularization (CN) in rats where topical bevacizumab was used as a positive control. The vasculature was photographed and blood vessel density was quantified using Aphelion imaging software. The extract was also evaluated for its anti proliferative activity by microculture tetrazolium test (MTT) assay using HeLa cancer cell line (ATCC).
  
  
  RESULTS
  VEGF increased the blood vessel density by 220% as compared to normal and thalidomide treatment decreased it to 67.2% in in ovo assay. In the in-vivo CN model, the mean neovascular density in the control group, the C. pyrenoidosa extract and bevacizumab group were found to be 100%, 59.02%, and 32.20%, respectively. The Chlorella pyrenoidosa extract negatively affected the viability of HeLa cells. An IC50 value of the extract was 570 μg/ml, respectively.
  
  
  CONCLUSIONS
  a significant antiangiogenic activity was observed against VEGF-induced neovascularization and antiproliferative activity by MTT assay. In this study, it could be attributed that the activity may be due to the presence of secondary metabolites in the C. pyrenoidosa extract.
authors.affiliation: Department of Pharmacy, Integrated Institute of Technology, Dwarka, New Delhi, India.
authors.forename: Mahender
authors.initials: M
authors.lastname: Kyadari
authors.affiliation: Department of Bio-Sciences, Jamia Millia Islamia, New Delhi, India.
authors.forename: Tasneem
authors.initials: T
authors.lastname: Fatma
authors.affiliation: Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Rajvardhan
authors.initials: R
authors.lastname: Azad
authors.affiliation: Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Thirumurthy
authors.initials: T
authors.lastname: Velpandian
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D002642:Chick Embryo; D002708:Chlorella / Q000737:chemistry*; D003315:Cornea / Q000098:blood supply; D004353:Drug Evaluation, Preclinical; D006367:HeLa Cells; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D020533:Angiogenesis Inhibitors; D010936:Plant Extracts
keywords: Algae; angiogenesis; chorioallantoic membrane; corneal neovascularization; vascular endothelial growth factor