Sulforaphane and Albumin Attenuate Experimental Intestinal Ischemia-Reperfusion Injury

Prophylactic Treatment of Intestinal Ischemia-Reperfusion Injury Reduces Mucosal Damage and Improves Intestinal Absorption

Purpose

Intestinal ischemia-reperfusion injury (i-IRI) involves a blood flow interruption in an intestinal segment followed by blood flow restoration. When blood flow is restored, oxidative and inflammatory molecules are distributed throughout the bloodstream, triggering both local and systemic damage. Our goal was to evaluate the potential of three antioxidant and/or anti-inflammatory compounds (curcumin, dexmedetomidine and α-tocopherol) to prevent or reverse local and systemic damage induced by i-IRI.

Methods

i-IRI was induced by placing a microvascular clip in the superior mesenteric artery of female WAG/RijHsd rats; the clip was removed after 1h and reperfusion was allowed for 4h. Curcumin (200 mg/kg, orally), α-tocopherol (20 mg/kg, i.p.), and dexmedetomidine (5 or 20 µg/kg, s.c.; DEX5 and DEX20, respectively) were administered. Blood and terminal ileum specimens were collected for biochemical and histological determination. Furthermore, D-xylose absorption test was performed to evaluate intestinal absorption; after completing the 1-hour ischemia and 4-hour reperfusion period, 1 mL of aqueous D-xylose solution (0.615 mg/mL) was administered orally, and one hour later, plasma D-xylose levels were quantified.

Results

The histological injury degree (HID) measured by the Chiu scale was significantly reduced when the treatments were applied (non-treated rats, 2.6 ± 0.75; curcumin, 1.54 ± 0.8; DEX5, 1.47 ± 0.7; DEX20 1.14 ± 0.5; and α-tocopherol, 1.01 ± 0.6); intestinal absorptive capacity also improved in all cases healthy rats (2.06 ± 0.07 µg/mL; non-treated, 1.18 ± 0.07 µg/mL; curcumin 1.76 ± 0.3 µg/mL; DEX5, 2.29 ± 0.2 µg/mL; DEX20, 2.25 ± 0.26 µg/mL; and α-tocopherol 1.66 ± 0.21 µg/mL). However, it failed to reduce liver enzyme levels. Finally, only dexmedetomidine significantly reduced urea and creatinine levels compared to non-treated animals.

Conclusion

All drugs were effective in reducing HID, although α-tocopherol was effective to a greater extent. Only dexmedetomidine reverted intestinal absorption to normal values of healthy animals.

When less is more: Experimental Bishop-Koop technique for reduction in the use of laboratory animals for intestinal pathophysiological studies

The use of animals to gain knowledge and understanding of diseases needs to be reduced and refined. In the field of intestinal research, because of the complexity of the gut immune system, living models testing is mandatory. Based on the 3Rs (replacement, reduction and refinement) principles, we aimed to developed and apply the derived-intestinal surgical procedure described by Bishop and Koop (BK) in rats to refine experimental gastrointestinal procedures and reduce the number of animals used for research employing two models of intestinal inflammation: intestinal ischemia-reperfusion injury and chemical-induced colitis. Our results show the feasibility of the application of the BK technique in rodents, with good success after surgical procedure in both small and large intestine (100% survival, clinical recovery and weight regain). A considerable reduction in the use of the number of rats in both intestinal inflammation models (80% in case of intestinal ischemia-reperfusion damage and 66.6% in chemical-induced colitis in our experimental design) was achieved. Compared with conventional experimental models described by various research groups, we report excellent reproducibility of intestinal damage and functionality, survival rate and clinical status of the animals when BK is applied.

Phenolic Acids from Fructus Chebulae Immaturus Alleviate Intestinal Ischemia-Reperfusion Injury in Mice through the PPARα/NF-κB Pathway

Intestinal ischemia/reperfusion (II/R) injury is a common life-threatening complication with high morbidity and mortality. Chebulae Fructus Immaturus, the unripe fruit of Terminalia chebula Retz., also known as “Xiqingguo” or “Tibet Olive” in China, has been widely used in traditional Tibetan medicine throughout history. The phenolic acids’ extract of Chebulae Fructus Immaturus (XQG for short) has exhibited strong antioxidative, anti-inflammation, anti-apoptosis, and antibacterial activities. However, whether XQG can effectively ameliorate II/R injuries remains to be clarified. Our results showed that XQG could effectively alleviate II/R-induced intestinal morphological damage and intestinal barrier injury by decreasing the oxidative stress, inflammatory response, and cell death. Transcriptomic analysis further revealed that the main action mechanism of XQG protecting against II/R injury was involved in activating PPARα and inhibiting the NF-κB-signaling pathway. Our study suggests the potential usage of XQG as a new candidate to alleviate II/R injury.

Translational Application of Fluorescent Molecular Probes for the Detection of Reactive Oxygen and Nitrogen Species Associated with Intestinal Reperfusion Injury

Acute mesenteric ischemia, caused by an abrupt interruption of blood flow in the mesenteric vessels, is associated with high mortality. When treated with surgical interventions or drugs to re-open the vascular lumen, the reperfusion process itself can inflict damage to the intestinal wall. Ischemia and reperfusion injury comprise complex mechanisms involving disarrangement of the splanchnic microcirculatory flow and impairment of the mitochondrial respiratory chain due to initial hypoxemia and subsequent oxidative stress during the reperfusion phase. This pathophysiologic process results in the production of large amounts of reactive oxygen (ROS) and nitrogen (RNS) species, which damage deoxyribonucleic acid, protein, lipids, and carbohydrates by autophagy, mitoptosis, necrosis, necroptosis, and apoptosis. Fluorescence-based systems using molecular probes have emerged as highly effective tools to monitor the concentrations and locations of these often short-lived ROS and RNS. The timely and accurate detection of both ROS and RNS by such an approach would help to identify early injury events associated with ischemia and reperfusion and increase overall clinical diagnostic sensitivity. This abstract describes the pathophysiology of intestinal ischemia and reperfusion and the early biological laboratory diagnosis using fluorescent molecular probes anticipating clinical decisions in the face of an extremely morbid disease.