Efficacy of curcumin on prevention of drug-induced nephrotoxicity: A review of animal studies

Drug-induced nephrotoxicity is a frequent serious adverse effect, contributing to morbidity and increased healthcare utilization. Prevention or reversal is key. Curcumin has useful biological features that include antioxidant, anti-inflammatory, and anticancer properties. This review covers aspects of curcumin in relation to prevention of drug-induced nephrotoxicity: dosage and schedule, effect on kidney biomarkers and histological changes, and mechanisms of curcumin's protective effects. Despite success in some animal models, human studies and clinical administration of curcumin for nephroprotection remains limited due to difficulty in achieving therapeutic levels following oral administration and in determining the optimal dosing schedule. Lack of sufficient evidence from animal studies, coupled with low systemic bioavailability, continues to limit the utilization of curcumin in addressing and controlling drug-induced nephrotoxicity. Therefore, human studies are required to fully assess and validate the therapeutic potential of curcumin.

Effect of Hypertonic Saline 5% on Early Graft Function and Urinary Interleukin 18 and Neutrophil Gelatinase-Associated Lipocalin in Deceased-Donor Kidney Transplantation

Ischemia reperfusion injury (IRI) is one of the main causes of delayed graft function (DGF) in deceased-donor kidney transplantation (DDKT). Evidences suggest that hypertonic saline (HS) has beneficial effects on IRI. The objective of the present study is to determine the effect of intraoperative HS, on graft function and urinary biomarkers of interleukin 18 (IL-18) and neutrophil gelatinase-associated lipocalin (NGAL), in patients with DDKT. The design of the study is a randomized, open-label, pilot trial in patients with DDKT. The intervention of the study is administration of 4 mL/kg HS, 5% before graft reperfusion. The primary endpoint was DGF. Fifty-eight (58) adult patients were randomized (HS, n = 32; control, n = 26). There were no significant differences between the two groups in terms of recipient, donor, and transplant characteristics. The rate of DGF was 20% in the HS group compared with 31.8% in the control group (Relative risk 0.63; 95% CI 0.23-1.67; P = 0.36). Serial serum creatinine in the first two days after surgery in addition to urine volumes during the first day after transplantation was significantly different in the HS group (P ≤ 0.05). The urinary NGAL and IL-18 were significantly lower in HS vs. control, at 24 h after transplantation (P ≤ 0.05). The frequency of adverse reactions was similar between groups. This study did not show any significant benefits from HS administration immediately before allograft reperfusion in terms of reducing DGF, serum creatinine at hospital discharge or length of hospital stay in deceased-donor kidney transplant patients.

The Effect of Osmotherapy and Tight Control of Acidosis on Early Graft Function among Deceased-Donor Kidney Transplant Recipients: A Randomized Controlled Trial

BACKGROUND

Reperfusion injury and the acid-base status of the transplant are important factors affecting post-transplantation graft function.

OBJECTIVE

We hypothesized that infusing hypertonic saline (HS) or tight control of acid-base status of the blood rushing through renal graft using sodium bicarbonate may have beneficial effects on early graft function.

METHODS

Candidates for deceased-donor kidney transplant were randomized into three groups. HS group (n=33) received 50 mL/kg normal saline (NS) titrated during operation plus 4 mL/kg of 5% HS just within graft reperfusion phase; bicarbonate group (n=37) was administered 60 mL/kg NS while their metabolic acidosis (base excess ≤5 mEq/L) was tightly corrected every 30 min with sodium bicarbonate; and a control group (n=36) that received 60 mL/kg normal saline while they were administered sodium bicarbonate only, if they encountered severe metabolic acidosis (base excess ≤15 mEq/L). The primary outcome was defined as early post-operative renal function evaluated based on serial serum creatinine levels. The study was registered in Iranian Registry of Clinical Trials (IRCT2013122815841N19).

RESULTS

Post-operative early graft function improved significantly during the first 3 days in the intervention groups (p<0.05). However, that beneficial effect no longer remained at the same level after the day four.

CONCLUSION

Timely administration of HS or tight control of metabolic acidosis with sodium bicarbonate infusion improve early renal function during renal transplant surgery.

Predictive Values of Urinary Interleukin 18 and Neutrophil Gelatinase-Associated Lipocalin for Delayed Graft Function Diagnosis in Kidney Transplantation

BACKGROUND

Delayed graft function is a main complication after deceased donor kidney transplantation that adversely affects graft outcome. Difficulties in prediction and early detection of delayed graft function have hindered the ability to perform proper therapeutic interventions. We investigated whether measuring urinary interleukin 18 and neutrophil gelatinase-associated lipocalin as markers of ischemia reperfusion injury could predict delayed graft function in deceased donor kidney transplant patients.

METHODS

We studied 69 patients undergoing kidney transplantation from deceased donor during early October 2013 to December 2014 at the Urology Research Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. Serial urine samples at 2, 24, and 48 h after transplantation were analyzed for interleukin 18 and neutrophil gelatinase-associated lipocalin levels.

RESULTS

Thirteen patients (18.9%) developed delayed graft function. Urine interleukin 18 to urine creatinine ratio was significantly higher in patients with delayed graft function compared to those with non-delayed graft function, at 2 (P=0.003), 24 (P<0.001) and 48 h (P=0.018) points. The levels of neutrophil gelatinase-associated lipocalin to urine creatinine ratio were significantly higher in the group with delayed graft function at the 24 (P=0.004) and 48 h (P=0.015) points. The receiver-operating characteristic curve analysis suggested that both urinary biomarkers at 24 h after transplantation had better accuracies for prediction of delayed graft function. In multivariate analysis, only urinary interleukin 18 to urine creatinine ratio improved the ability of clinical model for predicting delayed graft function.

CONCLUSION

Urinary interleukin 18 to urine creatinine ratio at 24 h post-transplantation, along with traditional markers such as relative fall in serum creatinine, urine output and other risk factors for delayed graft function, increased the ability to predict delayed graft function.

Immunomodulatory effect of hypertonic saline in hemorrhagic shock

Multiple organ dysfunction syndrome (MODS) and nosocomial infection following trauma-hemorrhage are among the most important causes of mortality in hemorrhagic shock patients. Dysregulation of the immune system plays a central role in MODS and a fluid having an immunomodulatory effect could be advantageous in hemorrhagic shock resuscitation. Hypertonic saline (HS) is widely used as a resuscitation fluid in trauma-hemorrhagic patients. Besides having beneficial effects on the hemodynamic parameters, HS has modulatory effects on various functions of immune cells such as degranulation, adhesion molecules and cytokines expression, as well as reactive oxygen species production. This article reviews clinical evidence for decreased organ failure and mortality in hemorrhagic shock patients resuscitated with HS. Despite promising results in animal models, results from pre-hospital and emergency department administration in human studies did not show improvement in survival, organ failure, or a reduction in nosocomial infection by HS resuscitation. Further post hoc analysis showed some benefit from HS resuscitation for severely-injured patients, those who received more than ten units of blood by transfusion, patients who underwent surgery, and victims of traumatic brain injury. Several reasons are suggested to explain the differences between clinical and animal models.