title: Antioxidant and relaxant activity of fractions of crude methanol extract and essential oil of Artemisia macrocephala Jacquem.
abstract: BACKGROUND
  The current work is an attempt to know about additional chemical profile of Artemisia macrocephala. Antioxidant activity is performed as the plant is reported to contain flavonoids, which have antioxidant activity in general. Relaxant activity of fractions of crude methanol extract is performed to know in which fraction(s) the relaxant constituents concentrate as we have already reported that its crude methanol has relaxant activity. Antispasmodic activity of essential oil is also performed as the plant is rich with essential oil.
  
  
  METHODS
  Phytochemical profile of the plant is performed. Free radical scavenging activity was performed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Relaxation activity tests of fractions and essential oil of Artemisia macrocephala were performed on sections of rabbits' jejunum. Calcium chloride curves were constructed to investigate the mode of action of plant extracts and its essential oil.
  
  
  RESULTS
  We detected carbohydrates, flavonoids and saponins in A. macrocephala. At concentration 0.005 mg/ml, free radical scavenging activity of ethyl acetate fraction was 121.5 ± 2.02% of ascorbic acid.n- hexane fraction relaxed spontaneous activity with EC50 0.74 ± 0.04 mg/ml. Essential oil relaxed spontaneous activity with EC50 0.8 ± 0.034 mg/ml. Chloroform and ethylacetate fractions relaxed both spontaneous and KCl-induced contractions suggesting its possible mode through calcium channels. Constructing calcium chloride curves, the test fractions showed a right shift in the EC50. Essential oil at concentration 0.1 mg/ml produced right shift with EC50 (log [Ca++]M) -2.08 ± 0.08 vs. control with EC50 -2.47 ± 0.07. The curve resembled the curves of verapamil, which caused a right shift at 0.1 μM, with EC50 -1.7 ±0.07 vs. control EC50 (log [Ca++]M) -2.45 ± 0.06.
  
  
  CONCLUSIONS
  Crude methanol and its fractions (ethyl acetate, chloroform and butanol) are rich sources of antioxidant constituents. The relaxing constituents following calcium channel blocking mechanisms are more concentrated in n-hexane, chloroform and ethyl acetate fractions that warrant isolation.
authors: Department of Pharmacology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan. niazpharmacist@yahoo.com
authors: Niaz
authors: N
authors: Ali
authors: Ismail
authors: I
authors: Shah
authors: Syed Wadood Ali
authors: SW
authors: Shah
authors: Ghayour
authors: G
authors: Ahmed
authors: Mohammad
authors: M
authors: Shoaib
authors: Muhammad
authors: M
authors: Junaid
authors: Waqar
authors: W
authors: Ali
authors: Zahoor
authors: Z
authors: Ahmed
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D019306:Artemisia / Q000737:chemistry*; D006801:Humans; D009126:Muscle Relaxation / Q000187:drug effects; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D010276:Parasympatholytics / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits
chemical_list: D000975:Antioxidants; D009822:Oils, Volatile; D010276:Parasympatholytics; D010936:Plant Extracts
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