The effects of nicardipine on neuroinflammation and cognitive function in aged rats following abdominal surgery

Abstract

Background/Objectives: Postoperative cognitive dysfunction (POCD) is a serious complication of anaesthesia/surgery. The present study investigated the effects of nicardipine—a calcium channel blocker—on neuroinflammation and POCD in rats. Methods: Following ethical approval, 30 Wistar albino rats were divided into three groups: control (Group C), surgery (Group S), and surgery and nicardipine (a single intraperitoneal dose of 5 mg/kg nicardipine) (Group N). Cognitive function was assessed 48 h postoperatively using the MWM test. The rats were sacrificed on the 5th day, and hippocampi were isolated and frozen at −80 ◦C on the same d ay. Hippocampal tissues were homogenised; ELISA and Western blot tests were performed to assess IL-1, IL-6, TNF-α, and caspase-3. Results: All groups showed a significant decrease in the time required to locate the hidden platform from day 1 to day 4. In the probe trial of the Morris water maze test, Group C spent more time in the target quadrant compared with Group S, indicating surgery-related cognitive impairment. The ELISA and Western blot analyses demonstrated that the hippocampal levels of IL-1, IL-6, TNF-α, and caspase-3 were significantly elevated in both Groups S and N compared with the controls. No statistically significant differences were observed between Groups S and N, indicating that the measured cognitive performance and hippocampal inflammatory responses were comparable between these groups. Conclusions: This study showed that a single intraperitoneal dose of 5 mg/kg of nicardipine did not measurably improve early postoperative cognitive performance or reduce hippocampal inflammation. In particular, nicardipine did not have a detectable effect on early postoperative neuroinflammation or cognition at the tested dose and timing in this rat model. Further studies exploring different doses and timing or repeated administration would help to clarify its potential role.