Effects of sevoflurane and fullerenol C60 on lower limb ischemia-reperfusion injury in streptozocin-induced diabetic mice

BACKGROUND

Ischemia-reperfusion injury (IRI) poses a significant challenge for physicians, necessitating the management of cell damage and the preservation of organ functions. Various surgical procedures, such as vascular surgery on extremities, temporary cross-clamping of the abdominal aorta in aortic surgery, and the use of a tourniquet in extremity surgeries, may induce lower limb IRI. The susceptibility to IRI is heightened in individuals with diabetes. This study aimed to investigate the effects of fullerenol C60 and sevoflurane on mouse muscle tissue in a lower limb IRI model and to assess their potential in preventing complications arising from ischemia-reperfusion in mice with streptozocin-induced diabetes.

METHODS

A total of 36 adult Swiss albino mice were randomly divided into six groups, each consisting of six mice: control group (group C), diabetes group (group D), diabetes-ischemia/reperfusion group (group DIR), diabetes-ischemia/reperfusion-fullerenol C60 group (group DIR-FC60), diabetes-ischemia/reperfusion-sevoflurane group (group DIR-S), and diabetes-ischemia/reperfusion-sevoflurane-fullerenol C60 group (DIR-S-FC60). Streptozocin (55 mg/kg) was intraperitoneally administered to induce diabetes in the relevant groups, with mice displaying blood glucose levels of 250 mg/dL or higher at 72 h were considered diabetic. After 4 weeks, all groups underwent laparotomy under anesthesia. In DIR-FC60 and DIR-S-FC60 groups, fullerenol C60 (100 mg/kg) was intraperitoneally administrated 30 min before the ischemia period. Sevoflurane, delivered in 100% oxygen at a rate of 2.3% and 4 L/min, was administered during the ischemia period in DIR-S and DIR-S-FC60 groups. In the IR groups, a microvascular clamp was placed on the infrarenal abdominal aorta for 120 min during the ischemia period, followed by the removal of the clamp and a 120-min reperfusion period. At the end of the reperfusion, gastrocnemius muscle tissues were removed for histopathological and biochemical parameter examinations.

RESULTS

Histopathological examination revealed a significant reduction in the disorganization and degeneration of muscle cells in the DIR-S-FC60 group compared to the DIR group (p = 0.041). Inflammatory cell infiltration was notably lower in the DIR-S, DIR-FC60, and DIR-S-FC60 groups than in the DIR group (p = 0.031, p = 0.011, and p = 0.013, respectively). The total damage scores in the DIR-FC60 and DIR-S-FC60 groups were significantly lower than in the DIR group (p = 0.018 and p = 0.008, respectively). Furthermore, the levels of malondialdehyde (MDA) in the DIR-S, DIR-FC60, and DIR-S-FC60 groups were significantly lower than in the DIR group (p < 0.001, p < 0.001, and p < 0.001, respectively). Catalase (CAT) enzyme activity in the DIR-S, DIR-FC60, and DIR-S-FC60 groups was higher than in the DIR group (p = 0.001, p = 0.014, and p < 0.001, respectively). Superoxide dismutase (SOD) enzyme activity in the DIR-FC60 and DIR-S-FC60 groups was also higher than in the DIR group (p < 0.001 and p = 0.001, respectively).

CONCLUSION

Our findings indicate that administering fullerenol C60 30 min prior to ischemia in diabetic mice, in combination with sevoflurane, led to a reduction in oxidative stress and the correction of IR-related damage in muscle tissue histopathology. We believe that the administration of fullerenol C60 before IR, coupled with sevoflurane administration during IR, exerts a protective effect in mice.

The Effect of Sevoflurane and Fullerenol C 60 on the Liver and Kidney in Lower Extremity Ischemia-Reperfusion Injury in Mice with Streptozocin-Induced Diabetes

Objective

This study aimed to demonstrate whether fullerenol C60, sevoflurane anesthesia, or a combination of both had protective effects on the liver and kidneys in lower extremity ischemia-reperfusion injury (IRI) in mice with streptozocin-induced diabetes.

Methods

A total of 46 Swiss albino mice were divided into six groups as follows: control group (group C, n=7), diabetes group (group D, n=7), diabetes-ischemia/reperfusion (group DIR, n=8), diabetes-ischemia/reperfusion-fullerenol C60 (group DIR-FC60, n=8), diabetes-ischemia/reperfusion-sevoflurane (group DIR-S, n=8), and the diabetes-ischemia/reperfusion-fullerenol C60-sevoflurane (group DIR-S-FC60, n=8). Fullerenol C60 (100mg/kg) was administered intraperitoneally 30 min before the ischemia-reperfusion procedure to the fullerenol groups (DIR-FC60 and DIR-S-FC60). In the DIR groups, 2 hours (h) ischemia-2h reperfusion periods were performed. In the sevoflurane groups, sevoflurane was applied during the ischemia-reperfusion period with 100% O2. Liver and kidney tissues were removed at the end of the reperfusion procedure for biochemical and histopathological examinations.

Results

In liver tissue, hydropic degeneration, sinusoidal dilatation, pycnotic nuclei, prenecrotic cells, and mononuclear cell infiltration in parenchyma were significantly more frequent in group DIR than in groups D and group C. In terms of the histopathologic criteria examined, more positive results were seen in group DIR-FC60, and when group DIR-FC60 was compared with group DIR, the difference was significant. The best results in AST, ALT, glucose, TBARS levels, and SOD enzyme activities in liver tissue were in group DIR-FC60 compared with group DIR, followed by groups DIR-S-FC60 and DIR-S, respectively. Regarding TBARS levels and SOD enzyme activities in kidney tissue, the best results were in groups DIR-FC60, DIR-S-FC60, and DIR-S, respectively.

Conclusion

According to our findings, it is clear that fullerenol C60 administered intraperitoneally 30 min before ischemia, alone or together with sevoflurane, reduces oxidative stress in distant organ damage caused by lower extremity IRI, and reduces liver and kidney tissue damage in histopathologic examinations.

Therapeutic Efficacy of Boric Acid Treatment on Brain Tissue and Cognitive Functions in Rats with Experimental Alzheimer's Disease

Introduction

Oxidative stress has an important role in the pathophysiology of Alzheimer's disease (AD), the most common type of dementia. Boric acid (BA) contributes significantly to the protection of the brain by reducing lipid peroxidation and supporting antioxidant defense. We aimed to evaluate the therapeutic potential of BA treatment in AD rats.

Materials and Methods

Four groups were formed as Control (C), Alzheimer's (A), Alzheimer's + Boric acid (ABA), Boric acid (BA). Intracerebroventricular injection of Streptozotocin (STZ) was preferred to create an AD. After 4 weeks, BA was applied 3 times every other day. The Radial Arm Maze Test (RAMT) was used to evaluate memory and learning abilities. Biochemical and histopathological evaluations were made in the hippocampus.

Results

Initial RAMT inlet/outlet (I/O) numbers were similar. Two weeks after STZ injection, I/O numbers decreased in group A and ABA compared to group C and BA (p<0.05). After the second BA application, I/O numbers increased in the ABA group compared to the A group (p<0.05). In group A, PON-1, TOS and OSI levels were higher and TAS levels were lower than in groups BA and C. After BA treatment, PON-1 and OSI levels were lower in the ABA group than in the A group (p<0.05). Although there was an increase in TAS value and a decrease in TOS, this did not make a statistical difference. The thickness of the pyramidal cell in CA1 and the granular cell layers in the dentate gyrus, and the number of intact and degenerated neurons in the pyramidal cell layer were similar between the groups.

Discussion

Significant improvement in learning and memory abilities after BA application is promising for AD.

Conclusion

These results show that BA application positively affects learning and memory abilities, and reduces oxidative stress. More extensive studies are required to evaluate histopathological efficacy.

Changes in substrate utilization rates during 40 min of walking within the Fatmax range

BACKGROUND AND AIMS

The aim of this study was to evaluate changes in fat oxidation rate during 40 min of continuous exercise and identify the intensity at the highest fat oxidation rate (Fatmax).

METHODS

A total of 14 sedentary males with age, body height, weight, and BMI averages of 29.3 ± 0.7 years, 178.3 ± 1.7 cm, 81.1 ± 3.9 kg, and 25.4 ± 0.9 kg/m², respectively, were included in the study. Fatmax was determined using an indirect calorimeter with an incremental treadmill walking test at least after 12 h of fasting. On a separate day, at least after 12 h of fasting, the participants walked for 40 min within their predetermined individual Fatmax heart rate and speed ranges.

RESULTS

The initial fat oxidation rate was not sustained within the first 16 min of exercise and was reduced; however, carbohydrate oxidation reached a stable level after nearly 10 min.

CONCLUSIONS

In sedentary individuals, during low-intensity physical activity, fat oxidation rates may not be sustainable as expected from Fatmax testing. Therefore, when exercise is prescribed, one should consider that the fat oxidation rate might decrease in sedentary overweight individuals.