ABSTRACT
Background: To evaluate the bronchoprotective effect of aqueous extract of Zingiber officinale (AZO) in guinea pigs and compare the same with that of standard drugs.Methods: Guinea pigs of either sex weighing between 350 to 450 Grams were randomly divided into 13 groups, each group containing 6 animals. Bronchospasm was induced by placing guinea pigs in histamine exposition chamber and exposing them to either 0.25% of histamine acid phosphate or 10% acetyl choline through a nebuliser under 40mm Hg pressure. The time for development of asphyxia was noted. After two and half hours, the animals were administered orally with vehicle / drugs as per the following: Gr I- Normal saline 1ml/100 Grams, Gr II- Salbutamol 1.6mg/kg, Gr III- Chlorpheniramine maleate 0.8mg/kg, Gr IV to Gr VI- AZO 200, 400, and 800mg/kg, Gr VII- AZO 200mg/kg and Salbutamol 0.8mg/kg. For acetylcholine-induced Bronchospasm Gr III animals received atropine 2mg/kg and Gr VII was not taken, rest others remaining the same. After 1 hour of treatment, the animals were again exposed to histamine or acetyl choline aerosol. The exposition time for each animal was again noted and mean increase or decrease in exposition time were noted. The data were subjected to stastical analysis by using paired ‘t’ test. Percentage of protection was also calculated.Results: AZO at all the doses studied (except 200mg/kg), showed highly significant increase in exposition time against histamine-induced bronchospasm. Combination of AZO (200mg/kg) with salbutamol (0.8mg/kg) also produced augmented effect. But against Acetylcholine induced bronchospasm, AZO did not produce any significant protective effect at any of the doses.Conclusions: AZO produced significant dose dependant bronchoprotection against histamine induced bronchospasm which might be due to antihistaminic action.