LAMOTRIGINE REDUCES INTESTINAL I/R INJURY IN THE RAT

MiR-497-5p ameliorates the oxyhemoglobin-induced subarachnoid hemorrhage injury in vitro by targeting orthodenticle homeobox protein 1 (Otx1) to activate the Nrf2/HO-1 pathway

Subarachnoid hemorrhage (SAH) is a neurological disorder that severely damages the brain and causes cognitive impairment. MicroRNAs are critical regulators in a variety of neurological diseases. MiR-497-5p has been found to be downregulated in the aneurysm vessel walls obtained from patients with aneurysmal subarachnoid hemorrhage, but its functions and mechanisms in SAH have not been reported. Therefore, this study was designed to investigate the effect of miR-497-5p and its related mechanisms in SAH. We established an in vitro SAH model by exposing PC12 cells to oxyhemoglobin (oxyHb). We found that miR-497-5p was downregulated in SAH serum and oxyHb-treated PC12 cells, and its overexpression inhibited the oxyHb-induced apoptosis, inflammatory response and oxidative stress via activation of the Nrf2 pathway. Mechanistically, the targeting relationship between miR-497-5p and Otx1 was verified by luciferase reporter assays. Moreover, Otx1 upregulation abolished the protective effects of miR-497-5p upregulation against oxyHb-induced apoptosis, inflammation and oxidative stress in PC12 cells. Collectively, our findings indicate that miR-497-5p could inhibit the oxyHb-induced SAH damage by targeting Otx1 to activate the Nrf2/HO-1 pathway, which provides a potential therapeutic target for SAH treatment.

Long-term protective effects of lamotrigine in a rat ovarian ischemia-reperfusion model

Ovarium torsion is a gynecological emergency that is common in women of reproductive age and requires early diagnosis and intervention. In this study, we aimed to investigate the long-term anatomical, histological and biochemical protective effects of lamotrigine in ovariums in the ischemia - reperfusion (I-R) model created experimentally in rats. A total of 40 female Sprague-Dawley rats, 14 weeks old, weighing 220-270 g were used in the study. The subjects were randomly distributed to form 4 groups named SHAM group, I - R group, I - R + Lamotrigine (LTG) group and R + LTG group. Under general anesthesia, the ovaries of the rats were reached and ischemia was created for 3 h with vascular clamps. 20 mg / kg LTG was administered intraperitoneally (ip.) to group 3 30 min before ischemia and to group 4 30 min before reperfusion. At the third hour of ischemia, the vascular clamps were opened and the abdomen of the rats was closed according to the surgical procedure. The rats were followed up for 28 days postoperatively and the ovarium tissues taken on the 28th day were examined anatomically and histologically. Biochemically, estradiol (E2), follicle stimulating hormone (FSH) and antimullerian hormone (AMH) levels were measured from blood samples taken from their hearts. Granulosa cells with diffuse vaculations were observed in degenerative follicles in group I-R. Again in this group, severe hemorrhage, fibrosis and edematous areas were observed in the ovarium stroma (Ovarian Histopathological Scoring (OHS): 7). In the I - R + LTG group, OHS was statistically significantly lower than the I - R group (OHS: 2; p < 0.000). In the R + LTG group, although the OHS score was calculated to be lower than the I - R group, there was no statistically significant difference (OHS: 6; p > 0.05). The protective effect of LTG against experimentally created ischemia and reperfusion damage was determined anatomically and histologically. No protective effect of LTG was observed in terms of FSH, E2 and AMH values measured from the blood sera of rats. These findings may provide a basis for future studies using LTG to treat ovarian ischemia-reperfusion injury.

The Effect of Antioxidant Astaxanthin on Intestinal Ischemia Reperfusion Damage in Rats

BACKGROUND

Mesenteric ischemia is a frequently encountered disease in surgical clinics, difficult to diagnose, and very mortal if not treated. Our study investigated the effects of astaxanthin, which is known to have potent antioxidant properties and is also known to have anti-inflammatory effects on ischemia-reperfusion (I/R) injury.

METHODS

A total of 32 healthy Wistar albino female rats were used in our study. Subjects were randomized and equally divided into 4 groups; control (laparotomy group only), I/R (transient mesenteric ischemia group only), astaxanthin 1 mg/kg and 10 mg/kg doses. The transient ischemia time was 60 minutes and the reperfusion time was 120 minutes. Tissue samples were taken from intracardiac blood and terminal ileum after reperfusion. Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) from blood samples, interleukin-1 (IL-1), IL-6, tumor necrosis factor-α (TNFα), Caspase-3, P53 tests from terminal ileum were studied. Tissue samples were also taken for histopathological evaluation.

RESULTS

At the end of the study, both doses of astaxanthin were found to significantly reduce MDA level, CAT, and SOD enzymatic activity, whereas higher doses of astaxanthin significantly reduced MDA level, CAT, and SOD enzyme activities. In addition, cytokines such as TNFα, IL-1 and IL-6 were found to be reduced at both doses of astaxanthin, but only significantly inhibited at higher doses. We observed that inhibition of apoptosis reduced caspase-3 activity and P53 and deoxyribonucleic acid (DNA) fragmentation.

CONCLUSION

Astaxanthin, a potent antioxidant, and anti-inflammatory, significantly reduces ischemia and reperfusion injury, especially when used at a dose of 10 mg/kg. These data need to be confirmed by larger animal series and clinical studies.

Pharmacological prevention of renal ischemia-reperfusion injury in a rat model

INTRODUCTION

Renal ischemia-reperfusion injury (IRI) can lead to significant morbidity and mortality. It remains a leading cause of acute kidney injury and is therefore an important issue in trauma and renal transplant surgery. Various pharmaceutical agents have been used in an attempt to dampen the harmful effects of IRI but few have been shown to be useful clinically. Riluzole, Lidocaine and Lamotrigine have been demonstrated to show anti-ischaemic properties in other organs; however, their use has not been tested in the kidneys. We investigated Riluzole, Lidocaine and Lamotrigine for their preventive effects of renal IRI using a rat model.

METHODS

Winstar rats (n = 48) were divided into four groups (n = 12 per group)-three treatment groups and one control group. Riluzole, Lidocaine and Lamotrigine were given prior to renal ischemia only (IO) or IRI. The degree of ischemia was measured by glutathione levels and a TUNEL assay was used to measure DNA fragmentation.

RESULTS

Riluzole, Lidocaine and Lamotrigine pre-treatment each resulted in statistically higher glutathione levels compared to controls (P = 0.002; P = 0.007 and P = 0.005, respectively). Riluzole and Lidocaine were also effective at preventing depletion of glutathione following IO (P = 0.007 and P = 0.014 respectively), while Lamotrigine was ineffective in IO (P = 0.71). The degree of DNA fragmentation seen on the TUNEL assay was markedly reduced in all three-drug groups in both IO and IRI.

DISCUSSION

Riluzole, Lidocaine and Lamotrigine all have anti-ischaemic effects in the rat kidney and can have potential therapeutic implications.

Biochemical, pathological and ultrastructural investigation of whether lamotrigine has neuroprotective efficacy against spinal cord ischemia reperfusion injury

INTRODUCTION

Lamotrigine, an anticonvulsant drug with inhibition properties of multi-ion channels, has been shown to be able to attenuates secondary neuronal damage by influencing different pathways. The aim of this study was to look into whether lamotrigine treatment could protect the spinal cord from experimental spinal cord ischemia-reperfusion injury.

MATERIALS AND METHODS

Thirty-two rats, eight rats per group, were randomly assigned to the sham group in which only laparotomy was performed, and to the ischemia, methylprednisolone and lamotrigine groups, where the infrarenal aorta was clamped for thirty minutes to induce spinal cord ischemia-reperfusion injury. Tissue samples belonging to spinal cords were harvested from sacrificed animals twenty-four hours after reperfusion. Tumor necrosis factor-alpha levels, interleukin-1 beta levels, nitric oxide levels, superoxide dismutase activity, catalase activity, glutathione peroxidase activity, malondialdehyde levels and caspase-3 activity were studied. Light and electron microscopic evaluations were also performed to reveal the pathological alterations. Basso, Beattie, and Bresnahan locomotor scale and the inclined-plane test was used to evaluate neurofunctional status at the beginning of the study and just before the animals were sacrificed.

RESULTS

Lamotrigine treatment provided significant improvement in the neurofunctional status by preventing the increase in cytokine expression, increased lipid peroxidation and oxidative stress, depletion of antioxidant enzymes activity and increased apoptosis, all of which contributing to spinal cord damage through different paths after ischemia reperfusion injury. Furthermore, lamotrigine treatment has shown improved results concerning the histopathological and ultrastructural scores and the functional tests.

CONCLUSION

These results proposed that lamotrigine may be a useful therapeutic agent to prevent the neuronal damage developing after spinal cord ischemia-reperfusion injury.

Effects of lithium and lamotrigine on oxidative-nitrosative stress and spatial learning deficit after global cerebral ischemia

Lithium (Li) and lamotrigine (LTG) have neuroprotective properties. However, the exact therapeutic mechanisms of these drugs have not been well understood. We investigated the antioxidant properties of Li (40 and 80 mg/kg/day) and LTG (20 and 40 mg/kg/day) in a rat model of global cerebral ischemia based on permanent bilateral occlusion of the common carotid arteries (BCAO). Nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione reductase (GSH-R), catalase (CAT) and superoxide dismutase (SOD) levels were measured as an indicator of oxidative-nitrosative stress in both prefrontal cortex (PFC) and hippocampus after 28 days of treatment. The spatial learning disability was also assessed at the end of the study by Morris water maze (MWM) test. All oxidative-nitrosative parameters were found to be higher in the groups under treatment than in sham. Both drugs caused a decrease in PFC NO and MDA elevation, meanwhile the increase in GSH, GSH-R, CAT and SOD levels was significantly more evident in treated groups. We also found higher PFC GSH-R and hippocampal SOD levels in BCAO + Li (80 mg/day) treated group when compared with BCAO + LTG 40 mg/day. MWM test data showed a similar increase in spatial learning ability in all groups under treatment. We found no other statistical difference in comparison of treated groups with different dosages. Our findings suggested that Li and LTG treatments may decrease spatial learning memory deficits accompanied by lower oxidative-nitrosative stress in global cerebral ischemia. Both drugs may have potential benefits for the treatment of vascular dementia in clinical practice.

Effects and mechanisms of chinese herbal medicine in ameliorating myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (MIR) injury is a major contributor to the morbidity and mortality associated with coronary artery disease, which accounts for approximately 450,000 deaths a year in the United States alone. Chinese herbal medicine, especially combined herbal formulations, has been widely used in traditional Chinese medicine for the treatment of myocardial infarction for hundreds of years. While the efficacy of Chinese herbal medicine is well documented, the underlying molecular mechanisms remain elusive. In this review, we highlight recent studies which are focused on elucidating the cellular and molecular mechanisms using extracted compounds, single herbs, or herbal formulations in experimental settings. These studies represent recent efforts to bridge the gap between the enigma of ancient Chinese herbal medicine and the concepts of modern cell and molecular biology in the treatment of myocardial infarction.

Protective effect of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion

The aim of this study is to evaluate the role of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into 3 groups: sham, I/R, and I/R + curcumin; each group contains 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were killed at the end of reperfusion and lung tissue samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by curcumin treatment have been reported. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissue samples. Intestinal I/R caused severe histopathological injury including oedema, haemorrhage, increased thickness of the alveolar wall, and infiltration of inflammatory cells into alveolar spaces. Curcumin treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and increase in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with curcumin therapy. It was concluded that curcumin treatment may have beneficial effects in acute lung injury, and therefore has potential for clinical use.

Toll-like receptors in ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injuries are implicated in a large array of pathological conditions such as myocardial infarction, cerebral stroke, and hepatic, renal, and intestinal ischemia, as well as following cardiovascular and transplant surgeries. The hallmark of these pathologies is excessive inflammation. Toll-like receptors (TLRs) are recognized as one of the main contributors to pathogen-induced inflammation and, more recently, injury-induced inflammation. Endogenous ligands such as low-molecular hyaluronic acid, fibronectin, heat shock protein 70, and heparin sulfate were all found to be cleaved in the inflamed tissue and to activate TLR2 and TLR4, initiating an inflammatory response even in the absence of pathogens and infiltrating immune cells. In this review, we discuss the contribution of TLR activation in hepatic, renal, cerebral, intestinal, and myocardial I/R injuries. A greater understanding of the role of TLRs in I/R injuries may aid in the development of specific TLR-targeted therapeutics to treat these conditions.

Panax notoginseng saponins attenuate acute lung injury induced by intestinal ischaemia/reperfusion in rats

BACKGROUND AND OBJECTIVE

Acute lung injury remains a challenge for both clinicians and scientists. The effects of Panax notoginseng saponins (PNS) on acute lung injury induced by intestinal ischaemia/reperfusion (II/R) were studied in rats.

METHODS

Forty-eight Wistar rats were randomly assigned to four groups: (1) a sham-operated group that received laparotomy without II/R (n= 12); (2) a sham + PNS group, which was identical to group 1 except for PNS treatment (n= 12); (3) an II/R group that had 1 h of intestinal ischaemia followed by 3 h of reperfusion (n= 12); and (4) an II/R + PNS group that received 100 mg/kg of PNS, i.v., 15 min before reperfusion (n= 12). The effects of PNS administration on lung tissue histology, activities of oxidant and antioxidant enzymes, levels of malondialdehyde, nitric oxide and inducible nitric oxide synthase activity were examined. Levels of surfactant protein B, cell numbers in BAL fluid and plasma levels of pro-inflammatory cytokines were also examined.

RESULTS

Compared with the II/R group, pulmonary parenchymal damage, activities of oxidant enzymes, levels of malondialdehyde and nitric oxide, inducible nitric oxide synthase activity in lung tissue, and plasma levels of pro-inflammatory cytokines were significantly reduced by PNS treatment. In addition, the decreases in antioxidant enzyme activities were prevented in the II/R + PNS group. Total leukocyte and neutrophil counts were significantly decreased by PNS treatment. The decline in surfactant protein B levels in BAL fluid was reduced in the II/R + PNS group compared with the II/R group.

CONCLUSIONS

Administration of PNS before reperfusion injury alleviates acute lung injury induced by II/R, and this is attributable to the antioxidant and anti-inflammatory effects of PNS.