title: High catechin concentrations detected in Withania somnifera (ashwagandha) by high performance liquid chromatography analysis.
abstract: BACKGROUND
  Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt).
  
  
  METHODS
  WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods.
  
  
  RESULTS
  High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight) and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%). Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin) have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g).
  
  
  CONCLUSIONS
  The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.
authors.affiliation: Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan.
authors.forename: Nadia
authors.initials: N
authors.lastname: Alam
authors.forename: Monzur
authors.initials: M
authors.lastname: Hossain
authors.forename: Md Ibrahim
authors.initials: MI
authors.lastname: Khalil
authors.forename: Mohammed
authors.initials: M
authors.lastname: Moniruzzaman
authors.forename: Siti Amrah
authors.initials: SA
authors.lastname: Sulaiman
authors.forename: Siew Hua
authors.initials: SH
authors.lastname: Gan
mesh_terms: D002392:Catechin / Q000032:analysis* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification; D010936:Plant Extracts / Q000032:analysis* / Q000302:isolation & purification; D032341:Withania / Q000737:chemistry*
chemical_list: D010636:Phenols; D010936:Plant Extracts; D002392:Catechin