title: Cissus quadrangularis Linn exerts dose-dependent biphasic effects: osteogenic and anti-proliferative, through modulating ROS, cell cycle and Runx2 gene expression in primary rat osteoblasts.
abstract: OBJECTIVE
  This report highlights phytoconstituents present in Cissus quadrangularis (CQ) extract and examines biphasic (proliferative and anti-proliferative) effects of its extract on bone cell proliferation, differentiation, mineralization, ROS generation, cell cycle progression and Runx2 gene expression in primary rat osteoblasts.
  
  
  METHODS
  Phytoconstituents were identified using gas chromatography-mass spectroscopy (GC-MS). Osteoblasts were exposed to different concentrations (10-100 μg/ml) of CQ extract and cell proliferation and cell differentiation were investigated at different periods of time. Subsequently, intracellular ROS intensity, apoptosis and matrix mineralization of osteoblasts were evaluated. We performed flow cytometry for DNA content and real-time PCR for Runx2 gene expression analysis.
  
  
  RESULTS
  CQ extract's approximately 40 bioactive compounds of fatty acids, hydrocarbons, vitamins and steroidal derivatives were identified. Osteoblasts exposed to varying concentrations of extract exhibited biphasic variation in cell proliferation and differentiation as a function of dose and time. Moreover, lower concentrations (10-50 μg/ml) of extract slightly reduced ROS intensity, although they enhanced matrix mineralization, DNA content in S phase of the cell cycle, and levels of Runx2 expression. However, higher concentrations (75-100 μg/ml) considerably induced the ROS intensity and nuclear condensation in osteoblasts, while it reduced mineralization level, proportion of cells in S phase and Runx2 level of the osteogenic gene.
  
  
  CONCLUSIONS
  These findings suggest that CQ extract revealed concentration-dependent biphasic effects, which would contribute notably to future assessment of pre-clinical efficacy and safety studies.
authors.affiliation: Molecular Endocrinology Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: S
authors.initials: S
authors.lastname: Siddiqui
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, Sao Paulo State University - UNESP, Araraquara, Sao Paulo, 14801-902, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Ahmad
authors.affiliation: Molecular Endocrinology Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: M
authors.initials: M
authors.lastname: Gupta
authors.affiliation: Molecular Endocrinology Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: V
authors.initials: V
authors.lastname: Rawat
authors.affiliation: Molecular Endocrinology Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: N
authors.initials: N
authors.lastname: Shivnath
authors.affiliation: Molecular & Human Genetics Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: M
authors.initials: M
authors.lastname: Banerjee
authors.affiliation: Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Khan
authors.affiliation: Molecular Endocrinology Laboratory, Department of Zoology, University of Lucknow, Lucknow, Uttar Pradesh, 226007, India.
authors.forename: M
authors.initials: M
authors.lastname: Arshad
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D032422:Cissus / Q000737:chemistry*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D004247:DNA