title: Inter-species comparative antioxidant assay and HPTLC analysis of sakuranetin in the chloroform and ethanol extracts of aerial parts of Rhus retinorrhoea and Rhus tripartita.
abstract: BACKGROUND
  Extensive research on Rhus (Anacardiaceae) shows their antioxidant potential, which warrants further evaluation of its other species.
  
  
  OBJECTIVE
  To perform a comparative antioxidant assay on extracts of R. retinorrhoea and R. tripartita, including sakuranetin quantification by a validated HPTLC method.
  
  
  METHODS
  In vitro antioxidant assay was performed on chloroform and ethanol extracts of R. retinorrhoea Steud. ex Oliv. (RRCE and RREE) and R. tripartita (Ucria) Grande (RTCE and RTEE) by DPPH radical scavenging (at 31.25, 62.5, 125, 250 and 500 μg/mL concentrations) and β-carotene-linoleic acid bleaching methods at 500 μg/mL concentration. Densitometric HPTLC method was developed and validated using toluene: ethyl acetate: methanol (8:2:0.2; v/v/v) as mobile phase, executed on glass-backed silica gel F254plate and scanned at 292 nm.
  
  
  RESULTS
  Antioxidant activity of Rhus extracts tested by the two methods (DPPH/BCB) was found in order of RTEE > RREE > RTCE > RRCE with IC50118.67/256.26, 315.75/82.35, 827.92/380.0 and 443.69/292.75, respectively. Scanning of the HPTLC plate provided an intense peak of sakuranetin at Rf= 0.59. The estimated sakuranetin content in the dry weight of the extracts was highest in RREE (27.95 μg/mg) followed by RRCE (25.22 μg/mg), RTEE (0.487 μg/mg) and RTCE (0.0 μg/mg). Presence of sakuranetin in RREE, RRCE and RTEE supported the highest antioxidant property of the two Rhus species. Nonetheless, low sakuratenin in R. tripartita indicated the presence of other bioactive constituents responsible for synergistic antioxidant activity.
  
  
  CONCLUSIONS
  The developed HPTLC method therefore guarantees its application in quality control of commercialized herbal drugs and formulations containing sakuranetin.
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Perwez
authors.initials: P
authors.lastname: Alam
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Mohammad Khalid
authors.initials: MK
authors.lastname: Parvez
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.|b Department of Pharmacognosy , College of Pharmacy, Omdurman Islamic University , Khartoum , Sudan.
authors.forename: Ahmed Hassan
authors.initials: AH
authors.lastname: Arbab
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Nasir Ali
authors.initials: NA
authors.lastname: Siddiqui
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Mohammed Salem
authors.initials: MS
authors.lastname: Al-Dosary
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Adnan Jathlan
authors.initials: AJ
authors.lastname: Al-Rehaily
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Sarfaraz
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: c Nanomedicine Research Unit, Department of Pharmaceutics , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Mohd Abul
authors.initials: MA
authors.lastname: Kalam
authors.affiliation: a Department of Pharmacognosy , College of Pharmacy, King Saud University , Riyadh , Kingdom of Saudi Arabia.
authors.forename: Mohammad Shamim
authors.initials: MS
authors.lastname: Ahmad
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D002725:Chloroform / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D000431:Ethanol / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D035261:Plant Components, Aerial / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D015203:Reproducibility of Results; D029045:Rhus / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D019207:beta Carotene / Q000737:chemistry; D000094162:Phytoalexins
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002725:Chloroform; D000431:Ethanol; D005419:Flavonoids; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D019207:beta Carotene; C099724:sakuranetin; D000094162:Phytoalexins; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Anacardiaceae; DPPH assay; flavanone; validated HPTLC; β-carotene bleaching method