Tetrandrine ameliorates sevoflurane­induced cognitive impairment via the suppression of inflammation and apoptosis in aged rats.

Tetrandrine is a bisbenzylisoquinoline alkaloid extracted from Stephania tetrandra, a traditional Chinese herbal medicine, which has been observed to exert anti­inflammatory effects. The aim of the current study was to investigate whether tetrandrine was able to ameliorate sevoflurane­induced cognitive impairment in aged rats. Male 20­month­old Sprague­Dawley rats underwent sevoflurane­induction in an environment containing 2% sevoflurane for 5 h. The Morris water maze test was used to measure the effect of tetrandrine on learning and memory in sevoflurane­treated aged rats. Western blot analysis of the protein expression levels of cyclooxygenase­2 (COX­2), inducible nitric oxide synthase (iNOS) and Bcl­2 was conducted. ELISAs were used to measure the levels of interleukin (IL)­1ß, tumor necrosis factor (TNF­α), nuclear factor­κB (NF­κB) and caspase­3. In the present study, tetrandrine improved the learning and memory deficits observed in sevoflurane­treated aged rats. Treatment with tetrandrine reduced the expression levels of COX­2, IL­1ß, TNF­α, NF­κB, iNOS and caspase­3, and increased the Bcl­2 protein expression in sevoflurane­treated aged rats. In conclusion, the current study indicated that tetrandrine ameliorates sevoflurane­induced cognitive impairment via the suppression of inflammation and apoptosis in aged rats. Thus, tetrandrine may be a potential novel candidate to protect against the effects of sevoflurane anesthesia on cognitive function.