Analgesic and anti-inflammatory activity of teucrium chamaedrys leaves aqueous extract in male rats

Current study was undertaken to investigate the analgesic and anti-inflammatory effects of the aqueous extract of Teucrium chamaedrys in mice and rats. For evaluating of analgesic and anti-inflammatory activity, we used the carrageenan-and dextran-induced paw oedema, acetic acid-induced writhing, tail flick and formalin pain tests. The extract of T. chamaedrys [50-200 mg/kg] and acetylsalicylic acid [100 mg/kg] produced a significant [P< 0.01] inhibition of the second phase response in the formalin pain model, while only the high dose [200 mg/kg] of the extract showed an analgesic effect in the first phase. The extract also inhibited acetic acid-induced abdominal writhes in a dose-dependent manner. The tail flick latency was dose dependently enhanced by the extract but this was significantly [P< 0.05] lower than that produced by morphine [10 mg/kg]. The extract [25-250 mg/kg] administered 1 hr before carrageenan-induced paw swelling produced a dose dependent inhibition of the oedema. No effect was observed with the dextran-induced oedema model. Results of the phytochemical screening show the presence of alkaloids, flavonoids and triterpenoids in the extract. The data obtained also suggest that the anti-inflammatory and analgesic effects of the extract may be mediated via both peripheral and central mechanisms. The role of alkaloids, flavonoids and triterpenoids will evaluate in future studies

Antinociceptive effect of promethazine in mice

The present study was undertaken to investigate the nociception activity of promethazine, a tranquillizer devoid of hypnotic activity in mice. Antinociception was evaluated, using the acetic acid-induced writhing, tail flick, hot plate and formalin pain tests. Promethazine [4 and 6 mg/kg] and acetylsalicylic acid [100 mg/kg] produced a significant inhibition of the second phase response in the formalin pain model [P<0.05] and the drug couldn't show an antinociceptive effect in the first phase. Morphine [10 mg/kg] inhibited both first and second phase response [P<0.01]. Drug also showed a dose-dependent inhibition of acetic acid-induced abdominal writhes. The tail flick and hot plate latency weren't different from control [P>0.05] and administration of naloxone [0.1 mg/kg] couldn't block the antinociceptive effect of promethazine. The data obtained suggest that antinociceptive effects of the promethazine may be mediated via peripheral and not central mechanisms