Effect of tempol on peripheral neuropathy in diet-induced obese and high-fat fed/low-dose streptozotocin-treated C57Bl6/J mice

Depot-specific adaption of adipose tissue for different exercise approaches in high-fat diet/streptozocin-induced diabetic mice

Background: Adipose tissue pathology plays a crucial role in the pathogenesis of type 2 diabetes mellitus. Understanding the impact of exercise training on adipose tissue adaptation is of paramount importance in enhancing metabolic health. In this study, we aimed to investigate the effects of various exercise modalities on three distinct adipose tissue depots, namely, interscapular brown adipose tissue (iBAT), subcutaneous white adipose tissue (sWAT), and epididymal white adipose tissue (eWAT), in a murine model of diabetes. Methods: Male C57BL/6J mice received a 12-week high-fat diet and a single injection of streptozotocin, followed by an 8-week exercise intervention. The exercise intervention included swimming, resistance training, aerobic exercise, and high-intensity interval training (HIIT). Results: We found that exercise training reduced body weight and body fat percentage, diminished adipocyte size and increased the expression of mitochondria-related genes (PGC1, COX4, and COX8B) in three adipose tissue depots. The effects of exercise on inflammatory status include a reduction in crown-like structures and the expression of inflammatory factors, mainly in eWAT. Besides, exercise only induces the browning of sWAT, which may be related to the expression of the sympathetic marker tyrosine hydroxylase. Among the four forms of exercise, HIIT was the most effective in reducing body fat percentage, increasing muscle mass and reducing eWAT adipocyte size. The expression of oxidative phosphorylation and thermogenesis-related genes in sWAT and eWAT was highest in the HIIT group. Conclusion: When targeting adipose tissue to improve diabetes, HIIT may offer superior benefits and thus represents a more advantageous choice.

HIIT Ameliorates Inflammation and Lipid Metabolism by Regulating Macrophage Polarization and Mitochondrial Dynamics in the Liver of Type 2 Diabetes Mellitus Mice

High-intensity interval training (HIIT), a new type of exercise, can effectively prevent the progression of metabolic diseases. The aim of this study was to investigate the effects of HIIT on liver inflammation and metabolic disorders in type 2 diabetes mellitus (T2DM) mice induced by a high-fat diet (HFD) combined with streptozotocin (STZ) and to explore the possible mechanisms of macrophage polarization and mitochondrial dynamics. Our results showed that HIIT can increase fatty acid oxidation-related gene (PPARα, CPT1α, and ACOX1) mRNA levels and decrease adipogenesis-related gene (PPARγ) mRNA levels to improve liver metabolism in T2DM mice. The improvement of lipid metabolism disorder may occur through increasing liver mitochondrial biosynthesis-related genes (PGC-1α and TFAM) and restoring mitochondrial dynamics-related gene (MFN2 and DRP1) mRNA levels. HIIT can also reduce the mRNA levels of liver inflammatory factors (TNF-α, IL-6, and MCP-1) in T2DM mice. The reduction in liver inflammation may occur through reducing the expression of total macrophage marker (F4/80) and M1 macrophage marker (CD86) mRNA and protein and increasing the expression of M2 macrophage marker (CD163, CD206, and Arg1) mRNA and protein in the liver. HIIT can also increase the expression of insulin signaling pathway (IRS1, PI3K, and AKT) mRNA and protein in the liver of T2DM mice, which may be related to the improvements in liver inflammation and lipid metabolism. In conclusion, these results suggested that 8 weeks of HIIT can improve inflammation and lipid metabolism disorders in the liver of type 2 diabetes mellitus mice, macrophage M1/M2 polarization, and mitochondrial dynamics may be involved in this process.

The effects on type 2 diabetes mellitus mouse femoral bone achieved by anti-osteoporosis exercise interventions

Purpose

Exercise therapy and key regulators of bone quality exert anti-hyperglycemic effects on type 2 diabetes mellitus (T2DM) mice. A number of programs have been reported to have an effect on bone disease in T2DM. Major unanswered questions concern the potential correlation of exercise with the improvement of bone quality in T2DM mice and how the nonlinear optical properties of bone are correlated with changes to its crystal structure.

Methods

Subjects were randomly divided into six groups: 1) control (C) group, which was fed a normal diet (n = 8); 2) T2DM quiet group, which was given a high-fat diet and quiet (n = 8); 3) T2DM plus swimming (T2DM+S) group, which received T2DM and swim training (n = 8); 4) T2DM plus resistance exercise (T2DM+RE) group, which was given T2DM and resistance exercise (n = 8); 5) T2DM plus aerobic exercise (T2DM+AE) group, with T2DM and medium-intensity treadmill exercise (n = 8); and 6) T2DM plus high-intensity interval training (T2DM+HIIT), with T2DM and high-intensity variable-speed intervention (n = 8). The levels of runt-related transcription factor 2 (RUNX2), osterix (OSX), and alkaline phosphatase (ALP), as well as the bone microstructure and morphometry, were measured at the end of the 8-week exercise intervention.

Results

Compared with the C group, the bone microstructure indexes [bone mineral density (BMD), bone volume/tissue volume (BV/TV), cortical thickness (Ct.Th), and connectivity density (Conn.D)], the bone biomechanical properties (maximum load, fracture load, yield stress, and elastic modulus), and the osteogenic differentiation factors (RUNX2, OSX, and BMP2) of the T2DM group were significantly decreased (all p < 0.05). Compared with the T2DM group, there were obvious improvements in the osteogenic differentiation factor (OSX) and Th.N, while the separation of trabecular bone (Tb.Sp) decreased in the T2DM+AE and T2DM+HIIT groups (all p < 0.05). In addition, the bone microstructure indicators BV/TV, tissue mineral density (TMD), Conn.D, and degree of anisotropy (DA) also increased in the T2DM+HIIT group, but the yield stress and Ct.Th deteriorated compared with the T2DM group (all p < 0.05). Compared with the T2DM+S and T2DM+RE groups, the BV/TV, trabecular number (Tb.N), Tb.Sp, and Conn.D in the T2DM+AE and T2DM+HIIT groups were significantly improved, but no significant changes in the above indicators were found between the T2DM+S and T2DM+RE groups (all p < 0.05). In addition, the BMD and the expression of ALP in the T2DM+AE group were significantly higher than those in the T2DM+HIIT group (all p < 0.05).

Conclusion

There was a significant deterioration in femur bone mass, trabecular bone microarchitecture, cortical bone geometry, and bone mechanical strength in diabetic mice. However, such deterioration was obviously attenuated in diabetic mice given aerobic and high-intensity interval training, which would be induced mainly by suppressing the development of T2DM. Regular physical exercise may be an effective strategy for the prevention of not only the development of diabetes but also the deterioration of bone properties in patients with chronic T2DM.

Neuronal Inflammation is Associated with Changes in Epidermal Innervation in High Fat Fed Mice

Peripheral neuropathy (PN), a debilitating complication of diabetes, is associated with obesity and the metabolic syndrome in nondiabetic individuals. Evidence indicates that a high fat diet can induce signs of diabetic peripheral PN in mice but the pathogenesis of high fat diet-induced PN remains unknown. PURPOSE: Determine if neuronal inflammation is associated with the development of mechanical hypersensitivity and nerve fiber changes in high fat fed mice. METHODS: Male C57Bl/6 mice were randomized to a standard (Std, 15% kcal from fat) or high fat diet (HF, 54% kcal from fat) for 2, 4, or 8 weeks (n = 11-12 per group). Lumbar dorsal root ganglia were harvested and inflammatory mediators (IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, GMCSF, RANTES) were quantified. Hindpaw mechanical sensitivity was assessed using the von Frey test. Intraepidermal nerve fiber density (IENFD) and TrkA nerve fiber density were quantified via immunohistochemistry. RESULTS: After 8 weeks, HF had greater body mass (33.3 ± 1.0 vs 26.7 ± 0.5 g, p < 0.001), fasting blood glucose (160.3 ± 9.4 vs 138.5 ± 3.4 mg/dl, p < 0.05) and insulin (3.58 ± 0.46 vs 0.82 ± 0.14 ng/ml, p < 0.001) compared to Std. IL-1α, RANTES and IL-5 were higher in HF compared to Std after 2 and 4 weeks, respectively (IL-1α: 4.8 ± 1.3 vs 2.9 ± 0.6 pg/mg, p < 0.05; RANTES: 19.6 ± 2.2 vs 13.3 ± 1.2 pg/mg p < 0.05; IL-5: 5.8 ± 0.7 vs 3.1 ± 0.5 pg/mg, p < 0.05). IENFD and TrkA fiber density were also higher in HF vs Std after 4 weeks (IENFD: 39.4 ± 1.2 vs 32.2 ± 1.3 fibers/mm, p < 0.001; TrkA: 30.4 ± 1.8 vs 22.4 ± 1.3 fibers/mm). There were no significant differences in hindpaw sensitivity for Std vs HF. CONCLUSION: Increased inflammatory mediators preceded and accompanied an increase in cutaneous pain sensing nerve fibers in high fat fed mice but was not accompanied by significant mechanical allodynia. Diets high in fat may increase neuronal inflammation and lead to increased nociceptive nerve fiber density.

An improved model of type 2 diabetes with effects on glucose tolerance, neuropathy and retinopathy with and without obesity

RATIONALE

Type 2 diabetes (T2D) costs billions of dollars annually, is also associated with pain (diabetic neuropathy), as well as retinopathy, lower urinary tract/urinary bladder dysfunction, depression, and systemic inflammation, affecting quality of life for patients. To that end, animal models are utilized to explore potential treatments, but may not reflect the complexity of the condition.

OBJECTIVE

We aimed to test an improved model of T2D that more closely mimics the clinical mechanisms and symptoms in an outbred strain of mouse.

FINDINGS

Male and female CD-1 mice (n = 72) were fed one of four diets: regular chow (REG), our Standard American Diet (SAD), a revised SAD (SAD2), or the commonly-used high-fat diet (HFD). Overall, HFD- and SAD-fed mice had significant weight gain and increased fat mass. Following injury, the SAD- and SAD2-fed mice showed protracted recovery, but the HFD-fed mice did not. Similarly, SAD- and SAD2-fed mice showed impaired retinal function compared to REG-fed mice, but the HFD-fed mice did not.

CONCLUSIONS

The SAD and SAD2 more closely model the problematic dietary intake and subsequent clinical symptoms associated with T2D.

POTENTIAL IMPACT OF STUDY

The adjusted SAD2 may be a better representation of a human-translatable diet than the SAD and HFD, and may allow for increased advances in the investigation of T2D-related symptoms.

Diet-induced rodent models of obesity-related metabolic disorders-A guide to a translational perspective

Diet is a critical element determining human health and diseases, and unbalanced food habits are major risk factors for the development of obesity and related metabolic disorders. Despite technological and pharmacological advances, as well as intensification of awareness campaigns, the prevalence of metabolic disorders worldwide is still increasing. Thus, novel therapeutic approaches with increased efficacy are urgently required, which often depends on cellular and molecular investigations using robust animal models. In the absence of perfect rodent models, those induced by excessive consumption of fat and sugars better replicate the key aspects that are the root causes of human metabolic diseases. However, the results obtained using these models cannot be directly compared, particularly because of the use of different dietary protocols, and animal species and strains, among other confounding factors. This review article revisits diet-induced models of obesity and related metabolic disorders, namely, metabolic syndrome, prediabetes, diabetes and nonalcoholic fatty liver disease. A critical analysis focused on the main pathophysiological features of rodent models, as opposed to the criteria defined for humans, is provided as a practical guide with a translational perspective for the establishment of animal models of obesity-related metabolic diseases.

The heterocyclic compound Tempol inhibits the growth of cancer cells by interfering with glutamine metabolism

Tempol (4-hydroxy-2,2,6,6-Tetramethylpiperidine-1-oxyl, TPL), a nitroxide compound, inhibits proliferation and increases the vulnerability of cancer cells to apoptosis induced by cytotoxic agents. However, the molecular mechanism of TPL inhibiting cancer cell proliferation has not been fully understood. In this study, we evaluated the metabolic effect of TPL on cancer cells and explored its cancer therapeutic potential. Extracellular flow assays showed that TPL inhibited cellular basal and maximal oxygen consumption rates of mitochondrial. ¹³C metabolic flux analysis showed that TPL treatment had minimal effect on glycolysis. However, we found that TPL inhibits glutamine metabolism by interfering with the oxidative tricarboxylic acid cycle (TCA) process and reductive glutamine process. We found that the inhibitory effect of TPL on metabolism occurs mainly on the step from citrate to α-ketoglutarate or vice versa. We also found that activity of isocitrate dehydrogenase IDH1 and IDH2, the key enzymes in TCA, were inhibited by TPL treatment. In xenograft mouse model, TPL treatment reduced tumor growth by inhibiting cellular proliferation of xenograft tumors. Thus, we provided a mechanism of TPL inhibiting cancer cell proliferation by interfering with glutamine utilization that is important for survival and proliferation of cancer cells. The study may help the development of a therapeutic strategy of TPL combined with other anticancer medicines.

Effect of mitoquinone (Mito-Q) on neuropathic endpoints in an obese and type 2 diabetic rat model

This study sought to determine whether the addition of mitoquinone (Mito-Q) in the diet is an effective treatment for peripheral neuropathy in animal models of diet-induced obesity (pre-diabetes) and type 2 diabetes. Unlike other anti-oxidative stress compounds investigated as a treatment for peripheral neuropathy, Mito-Q specifically targets mitochondria. Although mito-Q has been shown to reduce oxidative stress generated by mitochondria there have been no studies performed of the effect of Mito-Q on peripheral neuropathy induced by diet-induced obesity or type 2 diabetes. Diet-induced obese (12 weeks after high fat diet) or type 2 diabetic rats (12 weeks of high fat diet and 4 weeks after the onset of hyperglycemia) were treated via the diet with Mito-Q (0.93 g/kg diet) for 12 weeks. Afterwards, glucose utilization, vascular reactivity of epineurial arterioles to acetylcholine and peripheral neuropathy related endpoints were examined. The addition of Mito-Q to the diets of obese and diabetic rats improved motor and/or sensory nerve conduction velocity, cornea and intraepidermal nerve fibre density, cornea sensitivity and thermal nociception. Surprisingly, treating obese and diabetic rats with Mito-Q did not improve glucose utilization or vascular reactivity by epineurial arterioles to acetylcholine. These studies imply that mitochondrial dysfunction contributes to peripheral neuropathy in animal models of pre-diabetes and late-stage type 2 diabetes. However, improvement in peripheral neuropathy following treatment with Mito-Q was not associated with improvement in glucose utilization or vascular reactivity of epineurial arterioles to acetylcholine.

High-Intensity Interval Training Restores Glycolipid Metabolism and Mitochondrial Function in Skeletal Muscle of Mice With Type 2 Diabetes

High-intensity interval training has been reported to lower fasting blood glucose and improve insulin resistance of type 2 diabetes without clear underlying mechanisms. The purpose of this study was to investigate the effect of high-intensity interval training on the glycolipid metabolism and mitochondrial dynamics in skeletal muscle of high-fat diet (HFD) and one-time 100 mg/kg streptozocin intraperitoneal injection-induced type 2 diabetes mellitus (T2DM) mice. Our results confirmed that high-intensity interval training reduced the body weight, fat mass, fasting blood glucose, and serum insulin of the T2DM mice. High-intensity interval training also improved glucose tolerance and insulin tolerance of the T2DM mice. Moreover, we found that high-intensity interval training also decreased lipid accumulation and increased glycogen synthesis in skeletal muscle of the T2DM mice. Ultrastructural analysis of the mitochondria showed that mitochondrial morphology and quantity were improved after 8 weeks of high-intensity interval training. Western blot analysis showed that the expression of mitochondrial biosynthesis related proteins and mitochondrial dynamics related proteins in high-intensity interval trained mice in skeletal muscle were enhanced. Taken together, these data suggest high-intensity interval training improved fasting blood glucose and glucose homeostasis possibly by ameliorating glycolipid metabolism and mitochondrial dynamics in skeletal muscle of the T2DM mice.

Endothelial acid ceramidase in exosome-mediated release of NLRP3 inflammasome products during hyperglycemia: Evidence from endothelium-specific deletion of Asah1 gene

Exosomes have been demonstrated to be one of the mechanisms mediating the release of intracellular signaling molecules to conduct cell-to-cell communication. However, it remains unknown whether and how exosomes mediate the release of NOD-like receptor pyrin domain 3 (NLRP3) inflammasome products such as interleukin-1 beta (IL-1β) from endothelial cells. The present study hypothesized that lysosomal acid ceramidase (AC) determines the fate of multivesicular bodies (MVBs) to control the exosome-mediated release of NLRP3 inflammasome products during hyperglycemia. Using a streptozotocin (STZ)-induced diabetes mouse model, we found that endothelium-specific AC gene knockout mice (Asah1^fl/fl/EC^cre) significantly enhanced the formation and activation of NLRP3 inflammasomes in coronary arterial ECs (CECs). These mice also had increased thickening of the coronary arterial wall and reduced expression of tight junction protein compared to wild-type (WT/WT) littermates. We also observed the expression of exosome markers such as CD63 and alkaline phosphatase (ALP) was augmented in STZ-treated Asah1^fl/fl/EC^cre mice compared to WT/WT mice, which was accompanied by an increased IL-1β release of exosomes. In the primary cultures of CECs, we demonstrated that AC deficiency markedly enhanced the formation and activation of NLRP3 inflammasomes, but significantly down-regulated tight junction proteins when these cells were exposed to high levels of glucose. The CECs from Asah1^fl/fl/EC^cre mice had decreased MVB-lysosome interaction and increased IL-1β-containing exosome release in response to high glucose stimulation. Together, these results suggest that AC importantly controls exosome-mediated release of NLRP3 inflammasome products in CECs, which is enhanced by AC deficiency leading to aggravated arterial inflammatory response during hyperglycemia.

[Effect of the chemoprotectant tempol on anti-tumor activity of cisplatin]

OBJECTIVE

To investigate the effect of the chemoprotectant tempol on the anti-tumor activity of cisplatin (DDP).

METHODS

The cellular toxicity of tempol in human colon cancer SW480 cells and mouse colon cancer CT26 cells were evaluated using MTT and cell counting kit-8 assays. CalcuSyn software analysis was used to determine the interaction between tempol and DDP in inhibition of the cell viability. A subcutaneous homograft mouse model of colon cancer was established. The mice were randomly divided into control group, tempol group, cisplatin group and tempol + DDP treatment group with intraperitoneal injections of the indicated agents. The tumor size, body weight and lifespan of the mice were measured, and HE staining was used to analyze the cytotoxic effect of the agents on the kidney and liver. Immunohistochemistry and Western blotting were performed to detect the expression of Bax and Bcl2 in the tumor tissue, and TUNEL staining was used to analyze the tumor cell apoptosis. The level of reactive oxygen species (ROS) in the tumor tissue was determined using flow cytometry.

RESULTS

Tempol showed inhibitory effects on the viability of SW480 and CT26 cells. CalcuSyn software analysis showed that tempol had a synergistic anti-tumor effect with DDP (CI &lt; 1). In the homograft mouse model, tempol treatment alone did not produce obvious anti-tumor effect. HE staining showed that the combined use of tempol and DDP alleviated DDP-induced fibrogenesis in the kidneys, but tempol also reduced the anti-tumor activity of DDP. Compared with the mice treated with DDP alone, the mice treated with both tempol and DDP had a significantly larger tumor size (P &lt; 0.01) and a shorter lifespan (P &lt; 0.05). Tempol significantly reversed DDP-induced expression of Bax and Bcl2 in the tumor tissue and tumor cell apoptosis (P &lt; 0.001), and obviously reduced the elevation of ROS level in the tumor tissue induced by DDP treatment (P &lt; 0.05).

CONCLUSIONS

Tempol can attenuate the anti-tumor effect of DDP while reducing the side effects of DDP. Caution must be taken and the risks and benefits should be carefully weighed when considering the use of tempol as an anti-oxidant to reduce the toxicities of DDP.

Eruca sativa Meal against Diabetic Neuropathic Pain: An H2S-Mediated Effect of Glucoerucin

The management of pain in patients affected by diabetic neuropathy still represents an unmet therapeutic need. Recent data highlighted the pain-relieving efficacy of glucosinolates deriving from Brassicaceae. The purpose of this study was to evaluate the anti-hyperalgesic efficacy of Eruca sativa defatted seed meal, along with its main glucosinolate, glucoerucin (GER), on diabetic neuropathic pain induced in mice by streptozotocin (STZ). The mechanism of action was also investigated. Hypersensitivity was assessed by paw pressure and cold plate tests after the acute administration of the compounds. Once bio-activated by myrosinase, both E. sativa defatted meal (1 g kg⁻¹ p.o.) and GER (100 µmol kg⁻¹ p.o., equimolar to meal content) showed a dose-dependent pain-relieving effect in STZ-diabetic mice, but the meal was more effective than the glucosinolate. The co-administration with H₂S scavengers abolished the pain relief mediated by both E. sativa meal and GER. Their effect was also prevented by selectively blocking Kv7 potassium channels. Repeated treatments with E. sativa meal did not induce tolerance to the anti-hypersensitive effect. In conclusion, E. sativa meal can be suggested as a new nutraceutical tool for pain relief in patients with diabetic neuropathy.

Determination of peripheral neuropathy in high-fat diet fed low-dose streptozotocin-treated female C57Bl/6J mice and Sprague-Dawley rats

AIMS/INTRODUCTION

Peripheral neuropathy is a common complication of diabetes and also occurs in 30% of human obese individuals with impaired glucose tolerance. Even though peripheral neuropathy affects both sexes, most pre-clinical studies have been carried out using male rodents. The aim of the present study was to create diet-induced obesity and type 2 diabetes in female rats and mice in order to examine the development of peripheral neuropathy.

MATERIALS AND METHODS

At 12 weeks-of-age, rats and mice were separated into three groups. Two groups or rats and mice were fed a 60-kcal% high-fat diet for 12 weeks (rats) or 8 weeks (mice). To induce type 2 diabetes, one group of high-fat diet-fed rats and mice were treated with a low dose of streptozotocin. Analyses of multiple neural end-points were carried out 12 weeks later.

RESULTS

Glucose utilization was impaired in diet-induced obese female rats and mice, as was a number of neurological end-points including nerve conduction velocity, intraepidermal and subepithelial corneal nerve fiber densities, and thermal and mechanical sensitivity. When female diet-induced obese rats or mice were made hyperglycemic, glucose utilization and sensory nerve density of the skin and cornea, as well as thermal and mechanical sensitivity, were more significantly impaired compared with diet-induced obese female rodents.

CONCLUSIONS

These studies show that diet-induced obese and type 2 diabetic female rodents develop peripheral neuropathy that is similar to that occurring in male rodents. However, for female rats, more aggressive treatment is required to induce dietary obesity.

Intrinsic Activity of C57BL/6 Substrains Associates with High-Fat Diet-Induced Mechanical Sensitivity in Mice

Pain is significantly impacted by the increasing epidemic of obesity and the metabolic syndrome. Our understanding of how these features impact pain is only beginning to be developed. Herein, we have investigated how small genetic differences among C57BL/6 mice from 2 different commercial vendors lead to important differences in the development of high-fat diet-induced mechanical sensitivity. Two substrains of C57BL/6 mice from Jackson Laboratories (Bar Harbor, ME; C57BL/6J and C57BL/6NIH), as well as C57BL/6 from Charles Rivers Laboratories (Wilmington, MA; C57BL/6CR) were placed on high-fat diets and analyzed for changes in metabolic features influenced by high-fat diet and obesity, as well as measures of pain-related behaviors. All 3 substrains responded to the high-fat diet; however, C57BL/6CR mice had the highest weights, fat mass, and impaired glucose tolerance of the 3 substrains. In addition, the C57BL/6CR mice were the only strain to develop significant mechanical sensitivity over the course of 8 weeks. Importantly, the C57BL/6J mice were protected from mechanical sensitivity, which may be based on increased physical activity compared with the other 2 substrains. These findings suggest that activity may play a powerful role in protecting metabolic changes associated with a high-fat diet and that these may also be protective in pain-associated changes as a result of a high-fat diet. These findings also emphasize the importance of selection and transparency in choosing C57BL/6 substrains in pain-related research. PERSPECTIVE: Obesity and the metabolic syndrome play an important role in pain. This study identifies key differences in the response to a high-fat diet among substrains of C57BL/6 mice and differences in intrinsic physical activity that may influence pain sensitivity. The results emphasize physical activity as a powerful modulator of obesity-related pain sensitivity.

Biologically and chemically important hydrazino-containing imidazolines as antioxidant agents

Biologically and chemically useful hydrazinoimidazolines were evaluated as antioxidant and antihaemolytic agents. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH^•), galvinoxyl radical (GOR), nitric oxide (NO) and hydrogen peroxide (H₂O₂) scavenging assays, ferric ions reducing power assay, and ex vivo model of rat erythrocytes exposed to 2,2'-azobis(2-methylpropionamidine)dihydrochloride (AAPH) or H₂O₂ were used. The most potent DPPH^• scavengers proved to be hydrazinoimidazolines 3, 2, and 4, revealing excellent antiradical effects - superior or comparable to that of all antioxidant standards used. Moreover, these molecules showed strong NO neutralising potencies - better to that of ascorbic acid (AA) (3), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) (3 and 2), butylated hydroxytoluene (BHT) (3 and 2), and butylated hydroxyanisole (BHA) (3, 2, and 4). Compound 4 was also effective in GOR scavenging. The excellent scavenger of GOR, NO, and H₂O₂ proved to be structure 5, with the potency superior or comparable to the majority of antioxidant standards used. In turn, compound 9 was effective in H₂O₂ and GOR neutralisation. All hydrazinoimidazolines revealed the reducing power that is higher than BHT. Moreover, the protective effects of most test compounds on oxidatively stressed erythrocytes were observed. Some structure-activity relationships were disclosed. A significance of the primary hydrazino group on antioxidant effects was confirmed. The most likely DPPH^• and GOR scavenging mechanisms for test compounds were propound. Among all the investigated molecules, hydrazinoimidazolines 5, 3, 2, 4, and 9, due to their excellent or good antiradical activities, can represent promising antioxidant candidates with prospective utility for prevention of diseases related to reactive oxygen/nitrogen species.