D2-dopamine receptor and alpha2-adrenoreceptor-mediated analgesic response of quercetin.
Quercetin, a bioflavonoid (100-300 mg/kg) produced dose dependent increase in tail-flick latency, the analgesic effect being sensitive to reversal by naloxone (1 mg/kg). Prior treatment with haloperidol (1 mg/kg), D1/D2 receptor antagonist haloperidol, sulpiride (50 mg/kg), a selective D2 receptor antagonist, yohimbine (5 mg/kg), a alpha2-adrenoreceptor antagonist but not by SCH 23390 a, selective D1 receptor antagonist blocked this response. Apomorphine (1 mg/kg) a mixed D1/D2 dopamine receptor agonist, and quinpirole (0.5 mg/kg), a selective D2 receptor agonist also produced antinociception, that was reversed by haloperidol (1 mg/kg), sulpiride (50 mg/kg), but not by yohimbine (5 mg/kg). The antinociceptive action of quercetin (200 mg/kg) was potentiated by D2 agonist quinpirole (0.2 mg/kg). Dopamine D1 receptor agonist SKF38393 (10 and 15 mg/kg) failed to alter the antinociceptive effect of quercetin (200 mg/kg). Quercetin (200 mg/kg) reversed reserpine (2 mg/kg-4 hr) induced hyperalgesia, which was reversed by sulpiride but not by yohimbine. Thus, a role of dopamine D2 and alpha2-adrenoreceptors is postulated in the antinociceptive action of quercetin.
Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh-160 014, India.
Pattipati S
PS
Naidu
Amanpreet
A
Singh
Shrinivas K
SK
Kulkarni
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D011794:Quercetin / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000502:physiology*
D000700:Analgesics; D018341:Receptors, Adrenergic, alpha-2; D017448:Receptors, Dopamine D2; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D011794:Quercetin; D001058:Apomorphine