Publication:

Evaluation of zinc as anti-asthma agent: a preclinical study on guinea pigs

Background The role of intravenous magnesium sulfate in acute asthma is restricted to severe and resistant cases while that of zinc as prophylactic agent. What is quite interesting is to know the benefits of zinc in acute attack of asthma and that of magnesium as prophylactic agent. The objective of the study was to analyze the bronchodilatory effects of zinc sulfate and prophylactic role of magnesium sulfate using a preclinical model of histamine and acetylcholine induced acute bronchial asthma in conscious guinea pigs.

Methods Animals were exposed to histamine diphosphate (1%) and acetylcholine chloride (10%) aerosols before and after administration of the respective test drugs after acute and sub-acute treatment regimens. Time for onset of preconvulsive dyspnea (PCD) was noted and compared within and between the treatment groups interms of percentage of protection.

Results Magnesium significantly prolonged time for convulsion compared to control group. But this difference was insignificant when compared with antihistaminic and anticholinergic drugs. Zinc was superior to control and magnesium treatment group in sub-acute treatment study.

Conclusions Magensium sulfate has bronchodilatory effects but no prophylactic effects while it is vice versa with zinc sulfate.