Effects of corn silk aqueous extract on intraocular pressure of ocular hypertensive human subjects

Abstract

Stigma/style of Zea mays L (Corn silk) has been documented to have hypotensive effect on blood pressure and to relieve oedema. However we are not aware of any literature on its hypotensive effect on intraocular pressure (IOP) of humans or animals. We studied the effects of water only, masked doses of corn silk aqueous extract (60 mg/kg, 130 mg/kg, 192.5 mg/kg and 260 mg/kg body weight) on the IOP and blood pressure (BP) of twenty normotensives and twenty ocular hypertensive subjects. Also we compared the effects of the varied doses of corn silk aqueous extract (CSAE) with masked doses (5 mg/kg and 10 mg/kg body weight) of acetazolamide on IOP of ocular hypertensive subjects only. The results showed that the last three doses of CSAE lowered IOP and BP significantly (p<0.001) within eight hours of administration. The peak effect on IOP was observed after four hours while the peak effect on BP was observed after three hours of administration in the normotensives and ocular hypertensive subjects likewise the hypotensive effect was dose-dependent. The results also showed that 130 mg/kg body weight of CSAE produced the same hypotensive effect on IOP of ocular hypertensive subjects as 5 mg/kg body weight of acetazolamide. Therefore CSAE may have some IOP lowering effects that require further investigation in the management of ocular hypertension. (S Afr Optom 2013 72(3) 133-143)