Tetrandrine ameliorates sevoflurane-induced cognitive impairment via the suppression of inflammation and apoptosis in aged rats

Abstract

Tetrandrine is a bisbenzylisoquinoline alkaloid extracted from Stephania tetrandra, a traditional Chinese herbal medicine, which has been observed to exert anti-inflammatory effects. The aim of the current study was to investigate whether tetrandrine was able to ameliorate sevoflurane-induced cognitive impairment in aged rats. Male 20-month-old Sprague-Dawley rats underwent sevoflurane-induction 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 sevoflurane-treated aged rats. Western blot analysis of the protein expression levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and Bcl-2 was conducted. ELISAs were used to measure the levels of interleukin (IL)-1β, tumor necrosis factor (TNF-α), nuclear factor-κB (NF-κB) and caspase-3. In the present study, tetrandrine improved the learning and memory deficits observed in sevoflurane-treated aged rats. Treatment with tetrandrine reduced the expression levels of COX-2, IL-1β, TNF-α, NF-κB, iNOS and caspase-3, and increased the Bcl-2 protein expression in sevoflurane-treated aged rats. In conclusion, the current study indicated that tetrandrine ameliorates sevoflurane-induced 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.