title: Anti-chikungunya activity of luteolin and apigenin rich fraction from Cynodon dactylon.
abstract: OBJECTIVE
  To obtain luteolin and apigenin rich fraction from the ethanolic extract of Cynodon dactylon (L.) (C. dactylon) Pers and evaluate the fraction's cytotoxicity and anti-Chikungunya potential using Vero cells.
  
  
  METHODS
  The ethanolic extract of C. dactylon was subjected to silica gel column chromatography to obtain anti-chikungunya virus (CHIKV) fraction. Reverse phase-HPLC and GC-MS studies were carried out to identify the major phytochemicals in the fraction using phytochemical standards. Cytotoxicity and the potential of the fraction against CHIKV were evaluated in vitro using Vero cells. Reduction in viral replication was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) after treating the viral infected Vero cells with the fraction.
  
  
  RESULTS
  Reverse Phase-HPLC and GC-MS studies confirmed the presence of flavonoids, luteolin and apigenin as major phytochemicals in the anti-CHIKV ethanolic fraction of C. dactylon. The fraction was found to exhibit potent viral inhibitory activity (about 98%) at the concentration of 50 µg/mL as observed by reduction in cytopathic effect, and the cytotoxic concentration of the fraction was found to be 250 µg/mL. RT-PCR analyses indicated that the reduction in viral mRNA synthesis in fraction treated infected cells was much higher than the viral infected control cells.
  
  
  CONCLUSIONS
  Luteolin and apigenin rich ethanolic fraction from C. dactylon can be utilized as a potential therapeutic agent against CHIKV infection as the fraction does not show cytotoxicity while inhibiting the virus.
authors.affiliation: Plant Genetic Engineering Lab, Department of Biotechnology, Bharathiar University, Coimbatore, Tamilnadu, India; Department of Virology, King Institute of Preventive Medicine and Research, Chennai-600032, Tamilnadu, India.
authors.forename: Krishnan Saravana
authors.initials: KS
authors.lastname: Murali
authors.affiliation: Centre for Environmental Research and Development and Loyola Institute of Frontier Energy, Loyola College, Chennai-600034, Tamilnadu, India.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Sivasubramanian
authors.affiliation: Centre for Environmental Research and Development and Loyola Institute of Frontier Energy, Loyola College, Chennai-600034, Tamilnadu, India.
authors.forename: Savariar
authors.initials: S
authors.lastname: Vincent
authors.affiliation: Plant Genetic Engineering Lab, Department of Biotechnology, Bharathiar University, Coimbatore, Tamilnadu, India.
authors.forename: Shanmugaraj Bala
authors.initials: SB
authors.lastname: Murugan
authors.affiliation: Department of Virology, King Institute of Preventive Medicine and Research, Chennai-600032, Tamilnadu, India.
authors.forename: Bupesh
authors.initials: B
authors.lastname: Giridaran
authors.affiliation: Vellore Institute of Technology, Vellore-632001, Tamilnadu, India.
authors.forename: Sundaram
authors.initials: S
authors.lastname: Dinesh
authors.affiliation: Department of Virology, King Institute of Preventive Medicine and Research, Chennai-600032, Tamilnadu, India.
authors.forename: Palani
authors.initials: P
authors.lastname: Gunasekaran
authors.affiliation: Department of Virology, King Institute of Preventive Medicine and Research, Chennai-600032, Tamilnadu, India.
authors.forename: Kaveri
authors.initials: K
authors.lastname: Krishnasamy
authors.affiliation: Plant Genetic Engineering Lab, Department of Biotechnology, Bharathiar University, Coimbatore, Tamilnadu, India. Electronic address: rsathish@buc.edu.in.
authors.forename: Ramalingam
authors.initials: R
authors.lastname: Sathishkumar
keywords: Antiviral activity; Apigenin; Chikungunya virus; Cynodon dactylon; Flavonoids; Luteolin