Endothelium-dependent relaxation induced by hawthorn extract in rat mesenteric artery

Life Sci. 1998;63(22):1983-91. doi: 10.1016/s0024-3205(98)00476-7.


The extract prepared from hawthorn (Crataegus fruit) was examined for its relaxant effect in rat isolated mesenteric arteries. Hawthorn extract induced concentration-dependent relaxation of the U46619-precontracted artery with an IC50 of 0.22 +/- 0.02 mg/ml. Removal of the functional endothelium reduced by approximately 85% the maximum relaxant response to hawthorn extract. Pretreatment of the arterial tissues with N(G)-nitro-L-arginine methyl ester (3-10 microM) or methylene blue (3-10 microM) inhibited the relaxation induced by hawthorn extract, while indomethacin (10 microM) had no effect. L-arginine (3 mM) did not affect the relaxation induced by hawthorn extract but partially reversed the effect of 10 microM N(G)-nitro-L-arginine methyl ester. Iberiotoxin (100 nM) slightly but significantly inhibited the relaxant effect of hawthorn extract whilst glibenclamide (3 microM) was ineffective. Glibenclamide at 3 microM reversed the relaxation induced by pinacidil. N(G)-nitro-L-arginine methyl ester and methylene blue markedly inhibited acetylcholine-induced relaxation in endothelium-intact arteries. Hawthorn extract also reduced the contraction induced by phenylephrine (1 microM) or high Ki (60 mM) with respective IC50 values of 0.13 +/- 0.01 mg/ml and 0.11 +/- 0.01 mg/ml. In high K+-contracted arteries, hawthorn extract induced only 55% of relaxation while it caused a complete inhibition of the U46619- or phenylephrine-induced contraction. These results suggest that hawthorn contains active components which cause vasorelaxation in rat isolated mesenteric arteries. Nitric oxide but not other endothelium-derived vasoactive factors was probably involved in the relaxation induced by hawthorn extract.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / physiology
  • Enzyme Inhibitors / pharmacology
  • In Vitro Techniques
  • Indomethacin / pharmacology
  • Male
  • Mesenteric Arteries / drug effects*
  • Methylene Blue / pharmacology
  • Muscle Relaxation / drug effects
  • Muscle, Smooth, Vascular / drug effects*
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Plant Extracts / pharmacology
  • Potassium / pharmacology
  • Potassium Channel Blockers
  • Rats
  • Rats, Sprague-Dawley
  • Rosales / chemistry*


  • Anti-Inflammatory Agents, Non-Steroidal
  • Enzyme Inhibitors
  • Plant Extracts
  • Potassium Channel Blockers
  • Nitric Oxide Synthase
  • Potassium
  • Methylene Blue
  • NG-Nitroarginine Methyl Ester
  • Indomethacin