In vivo and in vitro Antiasthmatic Studies of Plant Piper longum Linn.

The fruits of Piper longum Linn. are used in allergic skin disorders and asthma. The effect of petroleum ether, alcoholic and decoction of the fruits of P. longum was studied for antihistaminic activity using Guinea pig ileum preparation (in vitro), histamine induced bronchospasm in Guinea pigs and haloperidol induced catalepsy in mice (in vivo). Its anti-allergic activity was evaluated using milk induced leukocytosis in mice and passive paw anaphylaxis in rats (in vivo). The extracts (100 μg mL-1) significantly (p<0.01) inhibited the histamine induced contraction of isolated Guinea-pig ileum preparation. The extracts (50, 100, 200 mg kg-1) showed the significant (p<0.01) activity and increase in dose of extract increased the % protection in histamine induced bronchospasm and also showed significant (p<0.01) activity in haloperidol induced catalepsy and passive paw anaphylaxis. In milk-induced leukocytes, petroleum ether and decoction extract (200 mg kg-1) showed significant (p<0.05) decrease in number of leukocytes and alcoholic extract didn’t show any significant effect.