Effect of Ulinastatin in the Treatment of Postperative Cognitive Dysfunction: Review of Current Literature

Postoperative cognitive dysfunction-current research progress

Postoperative cognitive dysfunction (POCD) commonly occurs after surgery, particularly in elderly individuals. It is characterized by a notable decline in cognitive performance, encompassing memory, attention, coordination, orientation, verbal fluency, and executive function. This reduction in cognitive abilities contributes to extended hospital stays and heightened mortality. The prevalence of POCD can reach 40% within 1 week following cardiovascular surgery and remains as high as 17% 3 months post-surgery. Furthermore, POCD exacerbates the long-term risk of Alzheimer's disease (AD). As a result, numerous studies have been conducted to investigate the molecular mechanisms underlying POCD and potential preventive strategies. This article provides a review of the research progress on POCD.

Effects of anesthetic adjunctive agents on postoperative cognitive dysfunction in elderly patients undergoing noncardiac surgery: A Bayesian network meta-analysis

BACKGROUND

Elderly patients are prone to postoperative cognitive dysfunction (POCD). The comparison of the effects of anesthetic adjuvant drugs on POCD in elderly patients undergoing noncardiac surgery remains controversial.

METHODS

The final search took place on June 10, 2023. Randomized controlled trials including ketamine, ulinastatin, dexmedetomidine, parecoxib, and midazolam on the prevention and treatment of POCD in elderly undergoing noncardiac surgery were collected. A Bayesian network meta-analysis was performed to quantitatively combine the evidence.

RESULTS

A total of 35 randomized trials were finally included in this systematic review, and the overall risk of bias is Allocation concealment. These anesthetic adjuvant drugs did not show significant differences in preventing POCD on postoperative days 1 and 7 compared with each other, but ulinastatin may be more effective in preventing POCD than dexmedetomidine [odds ratio (OR) = 0.28, 95% confidence interval (CI) = (0.10, 0.71)] and parecoxib [OR = 0.3, 95% CI = (0.10, 0.82 on postoperative day 3. The efficiency ranking results also find that ulinastatin and ketamine might provide better effects regarding POCD prevention.

CONCLUSIONS

Ketamine and ulinastatin might have better effects in preventing POCD in elderly patients undergoing noncardiac surgery. Our meta-analysis provided evidence for the use of ulinastatin and ketamine in the prevention of POCD in elderly patients undergoing noncardiac surgery.

Insights into Advanced Neurological Dysfunction Mechanisms Following DBS Surgery in Parkinson's Patients: Neuroinflammation and Pyroptosis

Parkinson's disease is a severe neurodegenerative disorder. Currently, deep brain electrical stimulation (DBS) is the first line of surgical treatment. However, serious neurological impairments such as speech disorders, disturbances of consciousness, and depression after surgery limit the efficacy of treatment. In this review, we summarize the recent experimental and clinical studies that have explored the possible causes of neurological deficits after DBS. Furthermore, we tried to identify clues from oxidative stress and pathological changes in patients that could lead to the activation of microglia and astrocytes in DBS surgical injury. Notably, reliable evidence supports the idea that neuroinflammation is caused by microglia and astrocytes, which may contribute to caspase-1 pathway-mediated neuronal pyroptosis. Finally, existing drugs and treatments may partially ameliorate the loss of neurological function in patients following DBS surgery by exerting neuroprotective effects.

Ulinastatin Alleviates Repetitive Ketamine Exposure-Evoked Cognitive Impairment in Adolescent Mice

Ketamine (KET) is widely used for induction and maintenance of anesthesia, and long-term use is required for treatment of depression patients. Repeated use of KET is associated with mood and memory disorders. Ulinastatin (UTI), a urinary trypsin inhibitor, has been widely undertaken as an anti-inflammatory drug and proved to have neuroprotective effects. The aim of this work was to determine whether prophylactic use of UTI could attenuate KET-induced cognitive impairment. It was found that repetitive KET anesthesia cause cognitive and emotional disorders in adolescent mice in WMZ and OFT test, while UTI pretreatment reversed the poor performance compared to the AK group, and the platform finding time and center crossing time were obviously short in the CK+UTI group (P < 0.05). Our ELISA experiment results discovered that UTI pretreatment reduced the expression levels of IL-1β and IL-6 induced by CK anesthesia compared to AK (P < 0.05). In addition, UTI pretreatment protected the cognitive function by restraining the expression levels of Tau protein, Tau phospho-396 protein, and Aβ protein in the CK group compared to the AK group in Western blotting (P < 0.05). The results suggested that UTI could act as a new strategy to prevent the neurotoxicity of KET, revealing a significant neuroprotective effect of UTI.

Transcutaneous electrical acupoint stimulation for postoperative cognitive dysfunction in geriatric patients with gastrointestinal tumor: a randomized controlled trial

Background

This study aimed to evaluate the effect of perioperative transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive dysfunction (POCD) in older patients who were diagnosed with gastrointestinal tumor and received radical resection of gastrointestinal tumors under general anesthesia.

Methods

A total of 68 patients who received radical resection of gastrointestinal tumors under general anesthesia were randomly divided into two groups. TEAS group patients received TEAS treatment. The treatment time was 30 min before the induction of anesthesia until the end of the surgery, 1 day before operation and from the first day to the third day after the operation. Except on the day of surgery, we treated the patients for 30 min once a day. In the sham TEAS group, the electronic stimulation was not applied and the treatment was the same as the TEAS group. The primary outcome was perioperative cognition evaluated by the Mini-Mental State Examination (MMSE) and secondary outcomes were the perioperative level of interleukin-6 (IL-6), S100 calcium-binding protein β (S100β), and C-reactive protein (CRP).

Results

The postoperative score of MMSE, orientation, memory, and short-term recall in the sham TEAS group was significantly lower than the preoperative and TEAS group (P < 0.05). The incidence of POCD in the TEAS group (21.88%) was lower than those in the sham TEAS group (40.63%). S100β, IL-6, and CRP in the TEAS group were significantly lower than those in the sham TEAS group on the third day after the operation (P< 0.05). Postoperative S100β, IL-6, and CRP in two groups were significantly higher than those before operation except for S100β on the third day after the operation in the TEAS group (P < 0.05).

Conclusions

Perioperative TEAS treatment reduced the postoperative inflammatory response and increased the postoperative cognitive function score and decrease the incidence of POCD in geriatric patients with gastrointestinal tumor.

Trial registration

ClinicalTrials.gov NCT04606888. Registered on 27 October 2020. https://register.clinicaltrials.gov.

Ulinastatin inhibits NLRP3-induced apoptosis in a PD cell model

Background

Emerging evidence suggests that inflammation induced by the inflammasome plays a crucial role in the course of Parkinson’s disease (PD). Ulinastatin (UTI) has shown significant anti-inflammatory effects. However, few studies have examined whether UTI protects neurons through its anti-inflammatory effects in PD. The purpose of this study is to determine whether UTI exerts neuroprotection in a PD cell model and to explore the mechanisms.

Methods

SH-SY5Y cells and nerve growth factor (NGF)-treated PC12 cells were used to establish MPP⁺ induced PD cell models. Cells were pre-treated with UTI, then cell viabilities were detected using the MTT assay. Lactate dehydrogenase (LDH) release was detected using the LDH release assay kit. Inflammatory factors such as IL-1β, IL-6, and TNF-α were detected using ELISA. The expression levels of TH, NLRP3, caspase-1, ASC, IL-1β, and IL-18 were measured using western blotting, and DA release was detected using HPLC. A NLRP3 activator Nigericin was used to verify the effect of NLRP3 in the neuroprotective mechanism of UTI.

Results

We observed decreased cell viability, increased apoptosis, and increased inflammatory factors such as IL-1β, IL-6, and TNF-α in the MPP⁺ induced PD model. We also found decreased DA secretion and TH expression, as well as increased NLRP3, caspase-1, ASC, IL-1α, and IL-18 expression in the MPP⁺ induced PD model. These changes were significantly attenuated by UTI pre-treatment in a dose dependent manner. NLRP3 activator Nigericin markedly increased LDH release, accelerated apoptosis, increased inflammation levels and decreased DA secretion and TH expression, suggesting that Nigericin eliminated the neuroprotective effect of UTI on MPP⁺ treated cells.

Conclusions

Our data demonstrated that UTI pre-treatment performed a neuroprotective role in the MPP⁺ induced PD cell models by inhibiting the NLRP3 pathway.

The Effect of Ulinastatin to the Learning and Memory in Zebrafish

Previous study indicated that Ulinastatin (UTI) increased glutamine uptake by upregulation of glutamate transporters in astrocytes. These glutamate transporters have important role to improve cognitive function in hippocampus. In this study, we wanted to demonstrate whether UTI could improve learning and memory by using zebrafish behavior model and bio-markers. Zebrafish were 6-8 months of age and were 2.5-3.5 cm long. They were divided into four groups by control, 1X PBS-injected control, UTI 10,000, and 50,000 injected group. All PBS and UTI injected zebrafish were anesthetized by Tricainemethanesulphonate. We measured total time, distance moved, and frequency in each compartment of T-maze. We also measured the expression levels of glutamate transporter levels and cognitive bio-markers such as c-fos, c-jun, BDNF. UTI affected the learning and memory in zebrafish in a dose-dependent manner. In 50,000 unit/kg UTI-treated zebrafish, there were increases of time, distance, and frequency in target compartment. In 50,000 unit/kg UTI-treated zebrafish, there was an increase of time in target compartment. There was no difference among control, PBS-injected, and UTI 10,000 unit/kg-treated groups. EAAT4 glutamate transporter, c-fos and BDNF were significantly increased in 50,000 unit/kg UTI-treated group. UTI-enhanced learning and memory in zebrafish. The expressions of EAAT4 glutamate transporter, c- fos and BDNF in zebrafish were highly correlated may play a role.

Atorvastatin protects against postoperative neurocognitive disorder via a peroxisome proliferator-activated receptor-gamma signaling pathway in mice

OBJECTIVE

Postoperative neurocognitive disorder (PND) is a main complication that is commonly seen postoperatively in elderly patients. The underlying mechanism remains unclear, although neuroinflammation has been increasingly observed in PND. Atorvastatin is a pleiotropic agent with proven anti-inflammatory effects. In this study, we investigated the effects of atorvastatin on a PND mouse model after peripheral surgery.

MATERIAL AND METHODS

The mice were randomized into five groups. The PND models were established, and an open field test and fear condition test were performed. Hippocampal inflammatory cytokine expression was determined using ELISA. Peroxisome proliferator-activated receptor-gamma (PPARγ) expression in the hippocampus was tested using qRT-PCR and western blot analysis.

RESULTS

On day 1 after surgery, inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6 showed a significant increase in the hippocampus, with prominent cognitive impairment. Atorvastatin treatment improved cognitive function in the mouse model, attenuated neuroinflammation, and increased PPARγ expression in the hippocampus. However, treatment with the PPARγ antagonist GW9662 partially reversed the protective effects of atorvastatin.

CONCLUSIONS

These results indicated that atorvastatin improves several hippocampal functions and alleviates inflammation in PND mice after surgery, probably through a PPARγ-involved signaling pathway.

Effect of Ulinastatin Combined With Dexmedetomidine on Postoperative Cognitive Dysfunction in Patients Who Underwent Cardiac Surgery

Background: Recent studies have shown that early diagnosis and intervention promote the patient's good prognosis. For patients who underwent cardiac surgery and require extracorporeal circulation support, the incidence of postoperative cognitive dysfunction (POCD) is higher than in other types of surgery due to greater changes in brain perfusion compared with normal physiological conditions. Recent studies have confirmed that the use of ulinastatin or dexmedetomidine in the perioperative period effectively reduces the incidence of POCD. In this study, ulinastatin was combined with dexmedetomidine to assess whether the combination of the two drugs could reduce the incidence of POCD.

Methods: One hundred and eighty patients with heart valve replacement surgery undergoing cardiopulmonary bypass from August 2017 to December 2018 were enrolled, with age 60–80 years, American Society of Anesthesiologists (ASA) grades I–III, education level above elementary school, and either gender. According to the random number table method, patients were grouped into ulinastatin + dexmedetomidine (U+D) group, ulinastatin (U) group, dexmedetomidine (D) group, and normal saline (N) control group. Group U was pumped 20,000 UI/kg immediately after induction and the first day after surgery, group D continued to pump 0.4 μg/kg/h from induction to 2 h before extubation, group U+D dexmedetomidine 0.4 μg/kg/h + ulinastatin 20,000 UI/kg, and group N equal volume of physiological saline. The patients were enrolled with Mini-Mental State Examination (MMSE) before surgery. The cognitive function was assessed by Montreal Cognitive Assessment (MoCA) on the first day before surgery and on the seventh day after surgery. Inflammatory factors, such as S100β protein, interleukin (IL)-6, matrix metalloproteinase (MMP)-9, and tumor necrosis factor (TNF)-α, were detected in peripheral blood before anesthesia (T0), immediately after surgery (T1), and immediately after extubation (T2).

Results: One hundred and fifty-four patients enrolled in this study. Compared with group N, the incidence of POCD in group U+D was the lowest (P < 0.05), followed by group U and group D. Group U+D had the lowest concentration of inflammatory factors at the T1 and T2 time points, followed by group U and group D.

Conclusions: Both ulinastatin and dexmedetomidine can reduce the perioperative inflammatory response and the incidence of POCD in patients with heart valve surgery, and their combination can better reduce the incidence of POCD.

[Effect of ulinastatin on isoflurane-induced neuronal apoptosis in the hippocampus of rats]

OBJECTIVE

To investigate the effect of ulinastatin pretreatment on isoflurane-induced mitochondria-dependent neuronal apoptosis in the hippocampus of rats.

METHODS

Thirty-six male SD rats were randomly assigned into control group, isoflurane group and ulinastatin group. In the latter two groups, the rats were subjected to acute exposure to 0.75% isoflurane for 6 h and pretreated with 50 000 U/kg of ulinastatin before isoflurane exposure, respectively. After the treatments, apoptosis of the hippocampal neurons was detected using TUNEL assay, and the mitochondrial membrane potential (△ ψm) was measured using JC-1 mitochondrial membrane potential kit; cytochrome C release and caspase-3 activity were examined with Western blotting, and intracellular reactive oxygen species (ROS) was detected using the fluorescent probe H2DCFDA.

RESULTS

Compared with those in the control group, the rats with acute exposure to isoflurane showed markedly increased TUNEL-positive cells in the hippocampus (P &lt; 0.05), which were obviously reduced by ulinastatin pretreatment (P &lt; 0.05). The △ψm of the hippocampal neurons was significantly reduced after isoflurane exposure (P &lt; 0.05), and was partly recovered by ulinastatin pretreatment (P &lt; 0.05). Acute exposure to isoflurane resulted in obviously increased cellular ROS, cytochrome C release and caspase-3 activity in the hippocampal neurons (P &lt; 0.05), and these changes were significantly inhibited by ulinastatin pretreatment (P &lt; 0.05).

CONCLUSIONS

Ulinastatin pretreatment provides neuroprotection against isoflurane-induced apoptosis of the hippocampal neurons in rats possibly by inhibiting mitochondria-dependent apoptosis pathway.

Ulinastatin attenuates isoflurane-induced cognitive dysfunction in aged rats by inhibiting neuroinflammation and β-amyloid peptide expression in the brain

Objective: Postoperative neurocognitive disease (PNCD) in the aged is a major clinical problem with unclear mechanisms. This study was designed to explore the mechanisms for ulinastatin (UTI) to attenuate isoflurane-induced cognitive decline in Fischer-344 rats. Methods: The rats were divided into four groups: Control (0.9% saline only), Isoflurane (exposure to 1.2% isoflurane), Isoflurane-plus-UTI (exposure to 1.2% isoflurane followed by 100,000 U/kg UTI injection i.v.) and UTI-plus-isoflurane (i.v. of 100,000 U/kg UTI followed by 1.2% isoflurane exposure). After respective tests, the concentrations of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the brain were determined by ELISA the expression of β-amyloid peptide (Aβ) and cleaved caspase-3 were measured by Western blot. Ratio of apoptotic cells after Barnes maze challenge was assessed by TUNEL assay. Results: In both Barnes Maze training and challenge, results indicated isoflurane-impaired learning capacity, while pre-and post-treatment with UTI could attenuate this phenomenon. The ratio of apoptotic cells and the expression of cleaved caspase-3 were increased after isoflurane exposure, indicating that isoflurane could induce neuronal apoptosis, while both pre- and post-treatment with UTI could diminish these effects. Moreover, UTI inhibited the expression of TNF-α, IL-1β and Aβ induced by isoflurane in rat brain harvested at 16 h after isoflurane exposure. Conclusion: These results suggest that UTI inhibits neuronal apoptosis in rat brain by attenuating increased expression of Aβ₄₂ and inflammatory cytokines, which may contribute to its alleviation of isoflurane-induced cognitive dysfunction in rats. Moreover, UTI pre-treatment before isoflurane exposure showed more effective than post-treatment.

Postoperative cognitive dysfunction in the aged: the collision of neuroinflammaging with perioperative neuroinflammation

The aging population is burgeoning globally and this trend presents great challenges to the current healthcare system as the growing number of aged individuals receives procedures of surgery and anesthesia. Postoperative cognitive dysfunction (POCD) is a severe postoperative neurological sequela. Advanced age is considered as an independent risk factor of POCD. Mounting evidence have shown that neuroinflammation plays an essential role in POCD. However, it remains debatable why this complication occurs highly in the aged individuals. As known, aging itself is the major common high-risk factor for age-associated disorders including diabetes, cardiovascular disease, cancer, and neurodegenerative diseases. Chronic low-grade neuroinflammation (dubbed neuroinflammaging in the present paper) is a hallmark alternation and contributes to age-related cognitive decline in the normal aging. Interestingly, several lines of findings show that the neuroinflammatory pathogenesis of POCD is age-dependent. It suggests that age-related changes, especially the neuroinflammaging, are possibly associated with the postoperative cognitive impairment. Understanding the role of neuroinflammaging in POCD is crucial to elucidate the mechanism of POCD and develop strategies to prevent or treat POCD. Here the focus of this review is on the potential role of neuroinflammaging in the mechanism of POCD. Lastly, we briefly review promising interventions for this neurological sequela.

Multi-organ protection of ulinastatin in traumatic cardiac arrest model

Background

Post-cardiac arrest syndrome, which has no specific curative treatment, contributes to the high mortality rate of victims who suffer traumatic cardiac arrest (TCA) and initially can be resuscitated. In the present study, we investigated the potential of ulinastatin to mitigate multiple organ injury after resuscitation in a swine TCA model.

Methods

Twenty-one male pigs were subjected to hemodynamic shock (40% estimated blood loss in 20 min) followed by cardiac arrest (electrically induced ventricular fibrillation) and respiratory suspension for 5 min, and finally manual resuscitation. At 5 min after resuscitation, pigs were randomized to receive 80,000 U/kg ulinastatin (n = 7) or the same volume of saline (n = 9) in the TCA group. Pigs in the sham group (n = 5) were not exposed to bleeding or cardiac arrest. At baseline and at 1, 3, and 6 h after the return of spontaneous circulation, blood samples were collected and assayed for tumor necrosis factor-alpha, interleukin 6, and other indicators of organ injury. At 24 h after resuscitation, pigs were sacrificed and apoptosis levels were assessed in samples of heart, brain, kidney, and intestine.

Results

One pig died in the ulinastatin group and one pig died in the TCA group; the remaining animals were included in the final analysis. TCA and resuscitation caused significant increases in multiple organ function biomarkers in serum, increases in tumor necrosis factor-alpha, and interleukin 6 in serum and increases in the extent of apoptosis in key organs. All these increases were lower in the ulinastatin group.

Conclusion

Ulinastatin may attenuate multiple organ injury after TCA, which should be explored in clinical studies.

Electronic supplementary material

The online version of this article (10.1186/s13017-018-0212-3) contains supplementary material, which is available to authorized users.

Surgery, neuroinflammation and cognitive impairment

Trauma experienced during surgery can contribute to the development of a systemic inflammatory response that can cause multi-organ dysfunction or even failure. Post-surgical neuroinflammation is a documented phenomenon that results in synaptic impairment, neuronal dysfunction and death, and impaired neurogenesis. Various pro-inflammatory cytokines, such as TNFα, maintain a state of chronic neuroinflammation, manifesting as post-operative cognitive dysfunction and post-operative delirium. Furthermore, elderly patients with post-operative cognitive dysfunction or delirium are three times more likely to experience permanent cognitive impairment or dementia. We conducted a narrative review, considering evidence extracted from various databases including Pubmed, MEDLINE and EMBASE, as well as journals and book reference lists. We found that further pre-clinical and well-powered clinical studies are required to delineate the precise pathogenesis of post-operative delirium and cognitive dysfunction. Despite the burden of post-operative neurological sequelae, clinical studies investigating therapeutic agents, such as dexmedetomidine, ibuprofen and statins, have yielded conflicting results. In addition, evidence supporting novel therapeutic avenues, such as nicotinic and HMGB-1 targeting and remote ischaemic pre-conditioning, is limited and necessitates further investigation.

Ulinastatin May Significantly Improve Postoperative Cognitive Function of Elderly Patients Undergoing Spinal Surgery by Reducing the Translocation of Lipopolysaccharide and Systemic Inflammation

Background: Studies have shown that perioperative inflammatory response is one of the important factors that caused postoperative cognitive dysfunction (POCD). Ulinastatin is a broad-spectrum protease inhibitor that inhibits inflammatory. We investigated the effects of ulinastatin on inflammatory response and early postoperative cognitive function in elderly patients undergoing spinal surgery.

Methods: This clinical trial was approved by the Xuanwu Hospital Ethical Committee (Registration number: ChiCTR-IPR-16008931). Sixty elderly patients undergoing elective spinal surgery with American Society of Anesthesiologists (ASA) status of I–II were randomized into ulinastatin and control groups; total intravenous anesthesia was performed. The elderly patients in ulinastatin group underwent intravenous infusion of ulinastatin 10,000 units/kg following anesthesia induction and before surgical incision, and 5000 units/kg on post-operative days 1 and 2. Cognitive function was determined with Montreal Cognitive Assessment (MOCA) test preoperatively and on post-operative day 7 by a neurologist. Serum lipopolysaccharide (LPS), interleukin-6 (IL-6), C-reactive protein (CRP), and matrix metalloprotease-9 (MMP-9) concentration levels were measured at baseline, the end of surgery, and on post-operative days 1 and 3.

Results: All elderly patients completed the study. Ulinastatin infusion significantly reduced the incidence of POCD in elderly patients undergoing spine surgery (ulinastatin group 16% vs. control group 43%, χ² = 5.079, P = 0.024, P < 0.05). The elderly patients in ulinastatin group exhibited lower serum LPS, IL-6, CRP, and MMP-9 concentrations, as well as a shortened peak value duration, compared with those in the control group following surgery (P < 0.05).

Conclusion: Systemic inflammation and translocation of LPS were inhibited by the infusion of ulinastatin in elderly patients undergoing spinal surgery. The anti-inflammation intervention with ulinastatin can significantly improve the elderly patients’ postoperative cognitive function.

Efficacy and Safety of Postoperative Pain Relief by Parecoxib Injection after Laparoscopic Surgeries: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This study aims to evaluate the efficacy and safety of parecoxib injection in pain relief after laparoscopic surgeries.

METHODS

A comprehensive literature search based on 4 online databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science) was applied to retrieve all related randomized controlled trials (RCTs). Two independent reviewers screened each article for eligibility according to the predetermined inclusion criteria. The Cochrane Collaboration's tool was applied to evaluate the methodological quality of included studies. A standardized data collection sheet was designed to extract data from included studies. RevMan version 5.3 (The Cochrane Collaboration, Copenhagen, Denmark) was selected to perform meta-analysis.

RESULTS

A total of 1,060 participants who were scheduled for gynecological laparoscopic surgery or laparoscopic cholecystectomy (LC) were enrolled in 12 selected RCTs. The methodological qualities of the studies were evaluated as moderate to high. The combined data showed that perioperative parecoxib injection could significantly reduce the proportion of patients who required adjuvant pain relieve after laparoscopic surgeries. Significantly lower pain scores in the parecoxib groups were observed, which proved that preoperative or intraoperative injection of 40 mg parecoxib was more effective than placebo for immediate pain relief after LC. But preoperative injection of 40 mg parecoxib showed no improvement compared with placebo in the management of immediate pain following gynecological laparoscopic surgery. The occurrence of adverse events showed no differences between perioperative parecoxib administration and placebo control.

CONCLUSION

Perioperative parecoxib administration was effective in reducing the proportion of patients who required adjuvant pain relief after laparoscopic surgeries without significant adverse events compared with placebo. The effect of parecoxib injection on immediate pain relief remains in question. Future RCTs with larger sample sizes are encouraged.

Overexpression of phosphodiesterase-4 subtypes involved in surgery-induced neuroinflammation and cognitive dysfunction in mice

Postoperative cognitive dysfunction (POCD) is characterized by cognitive impairments in patients after surgery. Hippocampal neuroinflammation induced by surgery is highly associated with POCD. Phosphodiesterase-4 (PDE4) is an enzyme that specifically hydrolyses cyclic adenosine monophosphate (cAMP), which plays an important role during neuroinflammation and the process of learning and memory. However, the role of PDE4 in the development of POCD remains unclear. Male 14-month-old C57BL/6 mice received carotid artery exposure to mimic POCD. First, we evaluated cognitive performance by a Morris water maze (MWM) and fear conditioning system (FCS) test after surgery. The expression of PDE4 subtypes, pro-inflammatory cytokines, p-CREB and PSD95 as well as cAMP levels were investigated. Then, we used rolipram, a PDE4 inhibitor, to block the effects of PDE4. The cognitive performance of the mice and the expression of PDE4 subtypes, pro-inflammatory cytokines, p-CREB and PSD95 as well as cAMP levels were examined again. Mice displayed learning and memory impairment, overexpression of PDE4B and PDE4D, elevation of pro-inflammatory cytokines, and reduction in the expression of p-CREB, PSD95 and cAMP levels after surgery. The expression of PDE4B and PDE4D in the hippocampus decreased following blocking of PDE4 by rolipram. Meanwhile, rolipram attenuated the cognitive impairment and the elevation of pro-inflammatory cytokines induced by surgery. Moreover, rolipram reversed the reduction of p-CREB and PSD95. These results indicate that PDE4 subtype overexpression may be involved in the development of surgery-induced cognitive dysfunction in mice.