Objective: The effect of EPHPH on aged deafness and its mechanism was explored by observing the effects of EPHPH on acoustic brainstem response threshold (ABRT), malondialdehyde (MDA), superoxide dismutase (SOD), total-nitrogen monoxide (NOS) and typing-nitrogen monoxide (iNOS) in cochleae tissues of senile model rats.
Method: ABRT value was measured by induced potentiometer, MDA was measured by TBA colorimetry, SOD was determined by nitrite method, NOS and iNOS was determined by spectrophotometry in cochleae tissues of senile model rats that separately administered by gavage the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH once a day for 6 months.
Result: ABRT value and MDA content notably increased, activities) of SOD, NOS and iNOS notably decreased in cochlear tissues of senile model rats from control. It indicated on relative analysis that relativity between ABRT value ascent and MDA ascent showed positive, relaxivities between ABRT value ascent and activity descents of SOD, NOS and iNOS showed all negative. It differently resisted ABRT value ascent and MDA ascent in cochlear tissues that senile model rats separately administered the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH whose relaxivities between quantity and efficiency showed all negative. It differently inhibited activity descents of SOD, NOS and iNOS in cochlear tissues that senile model rats separately administered various doses of EPHPH whose relaxivities between quantity and efficiency showed all positive.
Conclusion: EPHPH may relieve the degree of aged deafness and its mechanism may be connected with eliminating oxygen free radicals and increasing the activities of SOD, NOS and iNOS in cochleae of natural senile rats.