Resistance training and hawthorn extract ameliorate cognitive deficits in streptozotocin-induced diabetic rats

Coenzyme Q10 and exercise training reinstate middle cerebral artery occlusion-induced behavioral deficits and hippocampal long-term potentiation suppression in aging rats

RATIONAL

Patients experience post-stroke cognitive impairment during aging. To date, no specific treatment solution has been reported for this disorder.

OBJECTIVE

The purpose of this study was to evaluate the effects of exercise training and coenzyme Q10 supplementation on middle cerebral artery occlusion (MCAO) induced behavioral impairment, long-term potentiation inhibition and cerebral infarction size in aging rats.

METHODS

Fifty aging male rats underwent MCAO surgery and were randomly distributed in to the following groups: 1-Sham, 2- control, 3- Coenzyme Q10, 4- Exercise training and 5- Exercise training with Q10 supplementation (Ex + Q10). Aerobic training groups were allowed to run on a treadmill for 12 weeks. Q10 (50 mg/kg) was administered intragastrically by gavage. Morris water maze, shuttle box and elevated plus maze tests were used to evaluate cognitive function. The population spike (PS) amplitude and slope of excitatory postsynaptic potentials (EPSP) in the dentate gyrus area were recorded as a result of perforant pathway electrical stimulation.

RESULTS

Our study showed that Q10 and aerobic training alone ameliorate spatial memory in the acquisition phase, but have no effect on spatial memory in the retention phase. Q10 and exercise training synergistically promoted spatial memory in the retention phase. Q10 and exercise training separately and simultaneously mitigated cerebral ischemia-induced passive avoidance memory impairment in acquisition and retention phases. The EPSP did not differ between the groups, but exercise training and Q10 ameliorate the PS amplitude in hippocampal responses to perforant path stimulation. Exercising and Q10 simultaneously reduced the cerebral infarction volume.

CONCLUSION

Collectively, the findings of the present study imply that 12 weeks of aerobic training and Q10 supplementation alone can simultaneously reverse cerebral ischemia induced neurobehavioral deficits via amelioration of synaptic plasticity and a reduction in cerebral infarction volume in senescent rats.

The Effects of Physical Activity on Experimental Models of Vascular Dementia: A Systematic Review and Meta-Analysis

Background

Physical activity is associated with improved brain health and cognition in humans. However, the validity, range, and quality of evidence for the beneficial outcomes linked to exercise in experimental models of vascular dementia (VaD) have not been evaluated. We performed a systematic review and meta-analysis of studies that assessed the effect of exercise intervention on models of VaD to provide an unbiased and comprehensive determination of the cognitive function and brain morphology benefits of exercise.

Summary

A systematic search in three databases as well as study design characteristics and experimental data extraction were completed in December 2021. We investigated the effects of exercise on cognitive function and brain-morphology outcomes in VaD models. Twenty-five studies were included for systematic review, while 21 studies were included in the meta-analysis. These studies included seven models of VaD in rats (60%, 15 studies), mice (36%, 9 studies), and pigs (4%, 1 study). None of the included studies used aged animals, and the majority of studies (80%) used only male animals.

Key Message Exercise improves cognition but increased neuro-inflammation in VaD models

Exercise improved cognitive function as well as some markers of brain morphology in models of VaD. However, exercise increased anxiety and neuro-inflammatory signals in VaD models. Further, we observed increased reporting anomalies such as a lack of blinding to group treatment or data analysis and randomization of animals to groups. Our report could help in the appropriate design of experimental studies seeking to investigate the effects of exercise as a non-pharmacological intervention on VaD models with a high translational impact.

Effect of berberine on the hippocampal structure, biochemical factors, memory, and blood-brain barrier in rat model of transient global cerebral ischemia

Global cerebral ischemia (GCI) results in damage to the neurons and leads to cognitive impairments. Berberine (BBR) is known for its neuroprotective qualities. This study aimed to investigate the effects of BBR on memory, Blood-brain barrier (BBB) permeability, biochemical factors, and neuronal structure. Sixty-three adult male Wistar rats were divided randomly into Sham (21), GCI (21), and GCI + BBR (21) groups. The GCI + BBR group received 50 mg/kg of BBR for 7 days before and 6 h after 20 min of GCI induction. After 24 h, assessments included hippocampal neuronal structure, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPX) levels, memory performance, and BBB permeability. The GCI + BBR group reduced volume loss in the CA1 and its sublayers (oriens, pyramidal, and radiatum) compared to the GCI group (p < 0.0001, p < 0.001, p < 0.01 and p < 0.001, respectively). Additionally, the GCI + BBR group showed higher pyramidal neuron density (p < 0.0001) and number (p < 0.0001) compared to the GCI group. BBR also decreased MDA levels (p < 0.0001) and increased CAT activity (p < 0.0001) in the GCI + BBR group compared to the GCI group, with GPX and SOD activity approaching Sham levels (p < 0.0001, both). BBR demonstrated significant improvements in short and long-term memory compared to the GCI group (p < 0.01, p < 0.0001, respectively). Furthermore, BBB permeability in the GCI + BBR group was significantly reduced compared to the GCI group (p < 0.0001). These findings demonstrated BBR's potential to protect the neurons in the CA1 and BBB structures, enhance antioxidant activity, and alleviate GCI-induced memory impairments.

Anti-Diabetic Potential of Polyphenol-Rich Fruits from the Maleae Tribe-A Review of In Vitro and In Vivo Animal and Human Trials

The Maleae tribe consists of over one thousand species, including many well-known polyphenol-containing fruit crops with wide-ranging biological properties, e.g., apples (Malus), chokeberries (Aronia), pears (Pyrus), quinces (Cydonia, Chaenomeles), saskatoon (Amelanchier), loquats (Eriobotrya), medlars (Mespilus), rowans (Sorbus), and hawthorns (Crataegus). Considering the current interest in the concept of functional foods and the still-insufficient methods of diabetes management, the anti-diabetic potential of fruits has been studied intensively, including those of the Maleae tribe. This paper is the first comprehensive overview of this selected topic, covering articles published from 2000 to 2023 (131 articles in total). The first part of this review focuses on the potential mechanisms of action of fruits investigated so far (46 species), including their effects on tissue-specific glucose transport and the expression or activity of proteins in the insulin signalling pathway. The second part covers the phytocompounds responsible for particular fruits' activity-primarily polyphenols (e.g., flavonols, dihydrochalcones, proanthocyanidins, anthocyanins, phenolic acids), but also polysaccharides, triterpenes, and their additive and synergistic effects. In summary, fruits from the Maleae tribe seem promising as functional foods and anti-diabetic agents; however, their prospects for more expansive pro-health application require further research, especially more profound in vivo trials.

The Possibility of Using Fruit-Bearing Plants of Temperate Climate in the Treatment and Prevention of Diabetes

Diabetes mellitus is one of the most dangerous metabolic diseases. The incidence of this disease continues to increase and is often associated with severe complications. Plants and natural plant products with a healing effect have been successfully used in the treatment of many disease entities since the beginning of the history of herbalism and medicine. At present, great emphasis is placed on the biodiversity of crops and the replacement of the monoculture production system of popular temperate climate plants, such as apple, pear, plum, and vine, with alternative fruit species. Very promising fruit plants are Cornelian cherry (Cornus mas); mulberry (Morus alba); bird cherry (Prunus padus); sour cherry (Prunus cerasus); plants of the genus Amelanchier, Sorbus, and Crategus; medlar (Mespilus germanica); quince (Cydonia oblonga); plants of the genus Vaccinium; and wild roses. When promoting the cultivation of alternative fruit-bearing plants, it is worth emphasizing their beneficial effects on health. This systematic review indicates that the antidiabetic effect of various parts of fruit plants is attributed to the presence of polyphenols, especially anthocyanins, which have different mechanisms of antidiabetic action and can be used in the treatment of diabetes and various complications associated with this disease.

The preconditioning effect of different exercise training modes on middle cerebral artery occlusion induced-behavioral deficit in senescent rats

Introduction

Brain abilities decrease after brain stroke in elderly. The neuroprotective effect of exercise training has been proved in clinical trials and animal experiment. Nevertheless, it is not still clear what kind of exercise has greater protective effect. The present study aimed at investigating pre-conditioning effect of endurance, resistance, and concurrent training on learning ability, anxiety, and spatial memory in aged rats following stroke strength with middle cerebral artery occlusion.

Method

We used 50 male Wistar rats (age = 24 months) that were assigned randomly in five groups; 1: sham group, 2: Control group 3: Endurance training 4: Resistance training, and 5: concurrent training. The exercise training groups received training for four weeks. Following training, middle cerebral artery occlusion was applied to induce cerebral ischemia. Using the elevated plus maze, shuttle box test, and Morris water maze, neurocognitive functions were tested in the sample rats.

Results

It was found that resistance training did not affect spatial memory in the acquisition phase, while concurrent training and endurance training enhanced spatial memory in the acquisition phase. On the contrary, spatial memory was improved by resistance training in the retention phase, while concurrent and endurance exercises did not affect spatial memory in the retention phase. Passive avoidance learning ability at acquisition phase was more in resistance group compared to the endurance and concurrent training in shuttle box test, but in retention phase was similar between training groups. Unlike endurance and concurrent training, resistance training reduced anxiety in senescent rats.

Conclusion

All three exercise types alleviated aversive learning and memory impairment induced by stroke in senescent rats. Notably, the resistance training showed a greater protective effect compared to the other two training methods.

Protective effects of cinnamon on acetylcholinesterase activity and memory dysfunction in diabetic rats

OBJECTIVES

Regarding neurocognitive and immunomodulatory properties of cinnamon (Cinn) we aimed to investigate whether cinnamon regulates acetylcholinesterase (AChE) activity, and oxidative abnormalities with concomitant memory dysfunction in streptozotocin (STZ)-induced diabetes.

METHODS

Forty-seven male adult rats were divided into seven groups (n=8 animals): Control group: in these non-diabetic rats only saline 0.9% NaCl was gavaged, Diabetic (Dia) group: diabetic rats in them saline 0.9% NaCl was gavaged for six weeks. Dia-Cinn 100, Dia-Cinn 200, and Dia-Cinn 400, Dia-Met groups: in these diabetic rats the extract (100, 200, 400 mg/kg respectively) or metformin (300 mg/kg) was gavaged for six weeks. Passive avoidance performance, AChE enzyme activity, and oxidative indicators were examined among the groups.

RESULTS

Vs. the control group, blood glucose level and stay time in the dark were remarkably increased in Dia group whereas the latency time was decreased. Meanwhile, antioxidant levels (superoxide dismutase, catalase, and thiols) noticeably decreased in the Dia group compared to the Control group. On the other hand, Cinn extract espicailly at the highest dose recovered the changes similar to those found in the metformin-treated group.

CONCLUSIONS

These findings proposed that the cinnamon hydro-ethanolic extract promotes memory recovery in diabetic conditions through the atteuation of the AChE activity and oxidative injury.

Effectiveness of coenzyme Q10 on learning and memory and synaptic plasticity impairment in an aged Aβ-induced rat model of Alzheimer's disease: a behavioral, biochemical, and electrophysiological study

RATIONALE

Aging is the major risk factor for Alzheimer's disease (AD), and cognitive and memory impairments are common among the elderly. Interestingly, coenzyme Q10 (Q10) levels decline in the brain of aging animals. Q10 is a substantial antioxidant substance, which has an important role in the mitochondria.

OBJECTIVE

We assessed the possible effects of Q10 on learning and memory and synaptic plasticity in aged β-amyloid (Aβ)-induced AD rats.

METHODS

In this study, 40 Wistar rats (24-36 months old; 360-450 g) were randomly assigned to four groups (n = 10 rats/group)-group I: control, group II: Aβ, group III: Q10; 50 mg/kg, and group IV: Q10+Aβ. Q10 was administered orally by gavage daily for 4 weeks before the Aβ injection. The cognitive function and learning and memory of the rats were measured by the novel object recognition (NOR), Morris water maze (MWM), and passive avoidance learning (PAL) tests. Finally, malondialdehyde (MDA), total antioxidant capacity (TAC), total thiol group (TTG), and total oxidant status (TOS) were measured.

RESULTS

Q10 improved the Aβ-related decrease in the discrimination index in the NOR test, spatial learning and memory in the MWM test, passive avoidance learning and memory in the PAL test, and long-term potentiation (LTP) impairment in the hippocampal PP-DG pathway in aged rats. In addition, Aβ injection significantly increased serum MDA and TOS levels. Q10, however, significantly reversed these parameters and also increased TAC and TTG levels in the Aβ+Q10 group.

CONCLUSIONS

Our experimental findings suggest that Q10 supplementation can suppress the progression of neurodegeneration that otherwise impairs learning and memory and reduces synaptic plasticity in our experimental animals. Therefore, similar supplemental Q10 treatment given to humans with AD could possibly provide them a better quality of life.

Modulation of GPC-4 and GPLD1 serum levels by improving glycemic indices in type 2 diabetes: Resistance training and hawthorn extract intervention

Aims

This study was designed to investigate the effects of resistance training (RT) and hawthorn extract (Ha) on Glypican-4 (GPC-4) and Insulin-regulated glycosylphosphatidylinositol-specific phospholipase D (GPLD1) serum levels in T2DM and to examine the relationship of these variables with glycemic indexes.

Method

40 male Wistar rats were divided into five equal groups: Healthy Control (H-C), Diabetes Control (D-C), Diabetes Resistance training (D-RT), Diabetes Hawthorn (D-Ha), and Diabetes Resistance training Hawthorn (D-RT-Ha). T2DM was induced with a 4-week high-fat diet (HFD) and one dose of STZ intraperitoneal injection (35 mg/kg). 1-week after the injection, RT (with a range of 50%-100%1RM/3 day/week) and gavage of Ha extract (100 mg/kg/day) was performed for 12 weeks.

Results

The glycemic indices improvement (reducing blood glucose and increasing serum insulin level) caused by RT and/or Ha increased GPC-4 and decreased GPLD1 in the T2DM rats, but these positive changes were more effective in the combination of RT + Ha. A strong correlation was also observed between GPC-4 and GPLD1 with blood glucose and insulin.

Conclusion

The increase in serum GPC-4 levels was probably due to the direct effect of RT + Ha, and the improvement of glycemic indexes after RT and Ha. The double effect of RT + Ha can be a regulatory mechanism for GPC-4 and its related factors in controlling T2DM complications.

The effects of endurance exercise and metformin on memory impairment caused by diabetes

OBJECTIVES

Diabetes has a negative effect on learning and memory performance, and it is a risk factor for Alzheimer's disease and dementia development. The present study aims to investigate the effects of two kinds of endurance exercise including high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) as well as metformin on impaired memory and learning related to streptozotocin (STZ) induced diabetes in rats.

METHODS

Forty adult male rats (250 ± 20 g weight) were divided into five groups (n=8), including control, diabetic, as well as diabetic rats treated with metformin (300 mg/kg), and HIIT (20 m/min), and MICT (15 m/min) exercises. Diabetes was induced by STZ (60 mg/kg, i.p.). Serum glucose concentration and oxidative stress markers (SOD, CAT, thiol, and MDA) in the cortex and hippocampus were determined by colorimetric assay. Behavioral tests were performed with a passive avoidance test.

RESULTS

The diabetic groups treated with metformin and both HIIT, and MICT exercises improved the latency and the staying time in the darkroom and lightroom. The entrance frequency into the darkroom also was restored (p<0.01-p<0.001). In both HIIT and MICT exercises as well as metformin groups the oxidative stress induced by diabetes has been reversed and attenuation of the serum glucose level has been observed compared to non-treated diabetic ones (p<0.05-p<0.001).

CONCLUSIONS

The results of the present study revealed both HIIT and MICT exercises had protective effects against oxidative stress and behavioral impairments induced by diabetes and these effects were comparable to the effects of metformin.

Assessment of executive function in a rodent model of Type 1 diabetes

This study examined the impact of Type 1 Diabetes Mellitus (T1DM) on executive function using a series of operant conditioning-based tasks in rats. Sprague Dawley rats were randomized to either non-diabetic (n = 12; 6 male) or diabetic (n = 14; 6 male) groups. Diabetes was induced using multiple low-dose streptozotocin injections. All diabetic rodents were insulin-treated using subcutaneous insulin pellet implants (9-15 mM). At week 14 of the study, rats were placed on a food restricted diet to induce 5-10 % weight loss. Rodents were familiarized and their set-shifting ability was tested on a series of tasks that required continuous adjustments to novel stimulus-reward paradigms in order to receive food rewards. Results showed no differences in the number of trials, nor number and type of errors made to successfully complete each task between groups. Therefore, we report no differences in executive function, or more specifically set-shifting abilities between non-diabetic and diabetic rodents that receive insulin.

Neuroprotective Effect of Wharton's Jelly-Derived Mesenchymal Stem Cell-Conditioned Medium (WJMSC-CM) on Diabetes-Associated Cognitive Impairment by Improving Oxidative Stress, Neuroinflammation, and Apoptosis

According to strong evidence, diabetes mellitus increases the risk of cognitive impairment. Mesenchymal stem cells have been shown to be potential therapeutic agents for neurological disorders. In the current study, we aimed to examine the effects of Wharton's jelly-derived mesenchymal stem cell-conditioned medium (WJMSC-CM) on learning and memory, oxidative stress, apoptosis, and histological changes in the hippocampus of diabetic rats. Randomly, 35 male Sprague Dawley rats weighing 260-300 g were allocated into five groups: control, diabetes, and three diabetic groups treated with insulin, WJMSC-CM, and DMEM. The injections of insulin (3 U/day, S.C.) and WJMSC-CM (10 mg/week, I.P.) were done for 60 days. The Morris water maze and open field were used to measure cognition and anxiety-like behaviors. Colorimetric assays were used to determine hippocampus glutathione (GSH), malondialdehyde (MDA) levels, and antioxidant enzyme activity. The histopathological evaluation of the hippocampus was performed by Nissl staining. The expression levels of Bax, Bcl-2, BDNF, and TNF-α were detected by real-time polymerase chain reaction (RT-PCR). According to our findings, WJMSC-CM significantly reduced and increased blood glucose and insulin levels, respectively. Enhanced cognition and improved anxiety-like behavior were also found in WJMSC-CM-treated diabetic rats. In addition, WJMSC-CM treatment reduced oxidative stress by lowering MDA and elevating GSH and antioxidant enzyme activity. Reduced TNF-α and enhanced Bcl-2 gene expression levels and elevated neuronal and nonneuronal (astrocytes and oligodendrocytes) cells were detected in the hippocampus of WJMSC-CM-treated diabetic rats. In conclusion, WJMSC-CM alleviated diabetes-related cognitive impairment by reducing oxidative stress, neuroinflammation, and apoptosis in diabetic rats.

Interval training and Crataegus persica ameliorate diabetic nephropathy via miR-126/Nrf-2 mediated inhibition of stress oxidative in rats with diabetes after myocardial ischemia-reperfusion injury

Myocardial disorders are the most common cause of renal failure and mortality in diabetic patients, but the molecular mechanism of this process is not yet clear. The reduction of nuclear Erythroid2-related factor-2 (Nrf-2) and positive regulators of Nrf-2 proteins, such as DJ-1 and microRNA-126 (miR-126), after hypoxia and the promotion of reactive oxygen species, might be an intervention indicator in renal failure after myocardial ischemia-reperfusion. Therefore, this study evaluates the renoprotective effect of exercise training and Crataegus persica extract (CE) on myocardial ischemia-reperfusion-induced kidney injury in diabetic rats. Fifty rats were divided into five groups: healthy sedentary control (Con), sedentary diabetic (D), interval trained diabetic (TD), diabetic plus Crataegus persica extract treatment (CD), and interval trained diabetic plus Crataegus persica extract treatment (TCD) groups. The rats in the exercise groups were subjected to moderate-intensity interval training five days per week for ten weeks. The rats in CD and TCD groups received 300 mg/kg of Crataegus persica through gavage for ten weeks. Then, the subjects underwent 30 min of myocardial ischemia and subsequently reperfusion for 24 h. At the end of the experiment, insulin sensitivity, oxidative stress, renal function, histopathology of the kidney, Nrf-2, miR-126, and DJ-1 gene expression levels were evaluated. The results show that the treatments decreased elevated levels of renal oxidative stress, glomerular filtration rate, insulin sensitivity, and pathological score in diabetic rats. Also, the expression of Nrf-2 and miR-126, unlike DJ-1, decreased in diabetic rats due to interval training. Due to the results, diabetes aggravates acute myocardial ischemia-reperfusion-induced kidney injury, while moderate-intensity interval training and Crataegus persica treatment simultaneously ameliorate myocardial ischemia-reperfusion-induced renal injury via miR-126/Nrf-2 pathway and improve insulin sensitivity and renal function in type 1 diabetic rats.

In Vitro and Human Pilot Studies of Different Topical Formulations Containing Rosa Species for the Treatment of Psoriasis

The aim of this study was to evaluate the phytochemical profile and antioxidant properties of the extracts from three Rosa species (R. canina, R. damascena, R. cairo), to develop and investigate topical formulations with lyophilized forms of extracts for the treatment of psoriasis. Phytochemical screening and in vitro total antioxidant capacity (DPPH, FRAP, CUPRAC, SOD) of studied samples were examined and compared. Lyophilized extracts of roses were dissolved in Transcutol HP and different formulations of creams were prepared. Franz diffusion method was used to evaluate the drug release and biocompatibility was tested on HaCaT cells. Rosa damascene had the best results regarding all the analyses that were conducted. After the evaluation of topical products, the formulation with Rosa damascena extract in a self-emulsifying drug delivery system was tested on a human clinical study that involved 20 patients. At the end of the clinical study an improvement in the quality of life of the patients was observed and erythema, induration and scaling were reduced. The present study indicates that our examined extracts exhibited great phenolic content, antioxidant capacity and safety profile of topical formulation and therefore can be used as a reliable source of natural antioxidants and may be used as a complementary treatment to improve the quality life of patients with psoriasis or may be tested on another diseases.

Molecular Mechanisms of Hawthorn Extracts in Multiple Organs Disorders in Underlying of Diabetes: A Review

Diabetes mellitus (DM) is one of the most important metabolic disorders associated with chronic hyperglycemia and occurs when the body cannot manage insulin secretion, insulin action, or both. Autoimmune destruction of pancreatic beta cells and insulin resistance are the major pathophysiological factors of types 1 and 2 of DM, respectively. Prolonged hyperglycemia leads to multiple organs dysfunctions, including nephropathy, neuropathy, cardiomyopathy, gastropathy, and micro- and macrovascular disorders. The basis of the metabolic abnormalities in carbohydrate, fat, and protein in diabetes is insufficient action of insulin on various target tissues. Medicinal plants are rich sources of bioactive chemical compounds with therapeutic effects. The beneficial effects of leaves, fruits, and flowers extracts of Crataegus oxyacantha, commonly called hawthorn, belonging to the Rosaceae family, are widely used as hawthorn-derived medicines. Data in this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, Web of Science, and Scientific Information Database from 2000 to 2021. Based on this review, hawthorn extracts appear both therapeutic and protective effects against diabetic-related complications in various organs through molecular mechanisms, such as decreasing triglyceride, cholesterol, very low density lipoprotein and increasing the antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity, decreasing malondialdehyde level, and attenuating tumor necrosis factor alpha, interleukin 6 and sirtuin 1/AMP-activated protein kinase (AMPK)/nuclear factor kappa B (NF-κB) pathway and increasing the phosphorylation of glucose transporter 4, insulin receptor substrate 1, AKT and phosphoinositide 3-kinases, and attenuating blood sugar and regulation of insulin secretion, insulin resistance, and improvement of histopathological changes in pancreatic beta cells. Collectively, hawthorn can be considered as one new target for the research and development of innovative drugs for the prevention or treatment of DM and related problems.

Effects of Buprenorphine on the Memory and Learning Deficit Induced by Methamphetamine Administration in Male Rats

Little is known about the effects of methamphetamine (Meth) and buprenorphine (Bup) on memory and learning in rats. The aim of this investigation was to examine the impact of Meth and Bup on memory and learning. Fourteen male Wistar rats weighing 250–300 g were assigned to four groups: Sham, Meth, Bup, and Meth + Bup and were treated for 1 week. Spatial learning and memory, avoidance learning, and locomotion were assessed using the Morris water maze, passive avoidance learning, and open field tests, respectively. Meth and Bup impaired spatial learning and memory in rats. Co-administration of Meth + Bup did not increase the time spent in the target quadrant compared to Meth alone in the MWM. The Bup and Meh + Bup groups were found with an increase in step-through latency (STLr) and a decrease in the time spent in the dark compartment (TDC). Meth and Bup had no effects on locomotor activity in the open field test. Bup showed a beneficial effect on aversive memory. Since Bup demonstrates fewer side effects than other opioid drugs, it may be preferable for the treatment of avoidance memory deficits in patients with Meth addiction.

Swimming training and Plantago psyllium ameliorate cognitive impairment and glucose tolerance in streptozotocin-nicotinamide-induced type 2 diabetic rats

Brain malfunction is common in diabetic patients. On the other hand, a growing body of research points to the beneficial effect of medicinal plants and exercise training on insulin sensitivity and brain function. Therefore, the aim of the present study was to investigate the effect of co-administration of swimming training and Plantago psyllium (mixed with standard pelleted food at a weight ratio of 5%) on learning and memory impairment and glucose tolerance in type 2 diabetic rats. For this purpose, 10 healthy and 40 rats with type 2 diabetes were randomly allocated to five groups: healthy sedentary control group (Con), sedentary diabetic group (D), diabetic group subjected to swimming training (D + Tr), diabetic group receiving P. psyllium (D + Ps), and diabetic group subjected to swimming training and receiving P. psyllium (D + Ps + Tr). Diabetes was induced by a single intraperitoneal injection of nicotinamide (120 mg/kg) and streptozotocin (65 mg/kg) separately with 15 min intervals. Experimental groups were treated with swimming training and P. psyllium independently and simultaneously for 12 weeks. Lipid profile and food intake were measured and also, glucose tolerance was evaluated by glucose area under the curve (AUCg) using an oral glucose tolerance test. Passive avoidance learning (PAL) and memory were evaluated by shuttle box test and cognitive memory was assessed by novel object recognition (NOR) and elevated plus-maze (EPM) tests. Diabetic rats exhibited a significant increase in food intake, lipid profile, and AUCg compared to healthy rats. Step-through latency in the PAL acquisition trial (STL-a) and retention test (STL-r) were significantly lower in diabetic rats than in the control group. In the diabetic group without treatment, time spent in the dark compartment increased compared to the control group in the shuttle box test. Discrimination index and distance traveled reduced in diabetic rats. On the other hand, swimming training and P. psyllium alleviated food intake, lipid profile, and glucose tolerance in diabetic rats. Also, the STL-a, STL-r, discrimination index, and distance travelled in the D + Ps + Tr group were significantly more than the diabetic group. Results showed that 12 weeks of swimming training and receiving P. psyllium improved memory deficit in streptozotocin-nicotinamide-induced type 2 diabetic rats possibly through hypolipidemic and hypoglycemic effects. These results suggest that the administration of swimming training and P. psyllium simultaneously might be an effective intervention for the treatment of diabetes-induced behavioral deficits.

The role of traditional Chinese medicine in the treatment of cognitive dysfunction in type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic cognitive dysfunction (DCD) is mainly one of the complications of type 2 diabetes mellitus (T2DM) with complex and obscure pathogenesis. Extensive evidence has demonstrated the effectiveness and safety of traditional Chinese medicine (TCM) for DCD management.

AIM OF THE STUDY

This review attempted to systematically summarize the possible pathogenesis of DCD and the current Chinese medicine on the treatment of DCD.

MATERIALS AND METHODS

We acquired information of TCM on DCD treatment from PubMed, Web of Science, Science Direct and CNKI databases. We then dissected the potential mechanisms of currently reported TCMs and their active ingredients for the treatment of DCD by discussing the deficiencies and giving further recommendations.

RESULTS

Most TCMs and their active ingredients could improve DCD through alleviating insulin resistance, microvascular dysfunction, abnormal gut microbiota composition, inflammation, and the damages of the blood-brain barrier, cerebrovascular and neurons under hyperglycemia conditions.

CONCLUSIONS

TCM is effective in the treatment of DCD with few adverse reactions. A large number of in vivo and in vitro, and clinical trials are still needed to further reveal the potential quality markers of TCM on DCD treatment.

Securidaca inappendiculata Polyphenol Rich Extract Counteracts Cognitive Deficits, Neuropathy, Neuroinflammation and Oxidative Stress in Diabetic Encephalopathic Rats via p38 MAPK/Nrf2/HO-1 Pathways

Diabetic encephalopathy is one of the serious emerging complication of diabetes. Securidaca inappendiculata is an important medicinal plant with excellent antioxidant and anti-inflammatory properties. This study investigated the neuroprotective effects of S. inappendiculata polyphenol rich extract (SiPE) against diabetic encephalopathy in rats and elucidated the potential mechanisms of action. Type 2 diabetes mellitus (T2DM) was induced using high fructose solution/intraperitoneal injection of streptozotocin and the diabetic rats were treated with SiPE (50, 100 and 200 mg/kg) for 8 weeks. Learning and memory functions were assessed using the Morris water and Y maze tests, depressive behaviour was evaluated using forced swimming and open field tests, while neuropathic pain assessment was assessed using hot plate, tail immersion and formalin tests. After the experiments, acetylcholinesterase (AChE), oxidative stress biomarkers and proinflammatory cytokines, caspase-3 and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) were determined by ELISA kits. In addition, the expression levels of p38, phospho-p38 (p-p38), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by western blot analyses. The results indicated that SiPE administration significantly lowered blood glucose level, attenuated body weight loss, thermal/chemical hyperalgesia, improved behavioural deficit in the Morris water maze, Y maze test and reduced depressive-like behaviours. Furthermore, SiPE reduced AChE, caspase-3, NF-κB, malonaldehyde malondialdehyde levels and simultaneously increased antioxidant enzymes activity in the brain tissues of diabetic rats. SiPE administration also significantly suppressed p38 MAPK pathway and upregulated the Nrf2 pathway. The findings suggested that SiPE exerted antidiabetic encephalopathy effects via modulation of oxidative stress and inflammation.

Effects of the hydroalcoholic extract of Rosa damascena on hippocampal long-term potentiation in rats fed high-fat diet

High-fat diets (HFDs) and obesity can cause serious health problems, such as neurodegenerative diseases and cognitive impairments. Consumption of HFD is associated with reduction in hippocampal synaptic plasticity. Rosa damascena (R. damascena) is traditionally used as a dietary supplement for many disorders. This study was carried out to determine the beneficial effect of hydroalcoholic extract of R. damascena on in vivo hippocampal synaptic plasticity (long-term potentiation, LTP) in the perforant pathway (PP)-dentate gyrus (DG) pathway in rats fed with an HFD. Male Wistar rats were randomly assigned to four groups: Control, R. damascena extract (1 g/kg bw daily for 30 days), HFD (for 90 days) and HFD + extract. The population spike (PS) amplitude and slope of excitatory post-synaptic potentials (EPSP) were measured in DG area in response to stimulation applied to the PP. Serum oxidative stress biomarkers [total thiol group (TTG) and superoxide dismutase (SOD)] were measured. The results showed the HFD impaired LTP induction in the PP-DG synapses. This conclusion is supported by decreased EPSP slope and PS amplitude of LTP. R. damascena supplementation in HFD animals enhanced EPSP slope and PS amplitude of LTP in the granular cell of DG. Consumption of HFD decreased TTG and SOD. R. damascena extract consumption in the HFD animals enhanced TTG and SOD. These data indicate that R. damascena dietary supplementation can ameliorate HFD-induced alteration of synaptic plasticity, probably through its significant antioxidant effects and activate signalling pathways, which are critical in controlling synaptic plasticity.

Regulatory effects of hawthorn polyphenols on hyperglycemic, inflammatory, insulin resistance responses, and alleviation of aortic injury in type 2 diabetic rats

Hawthorn polyphenol extract (HPE) is beneficial for patients with type 2 diabetes (T2D). However, the mechanism underlying its beneficial effects remains unclear. We investigated the inhibitory effects and mechanisms of HPE on insulin resistance, inflammation, and aortic injury in T2D rats, using metformin (MF) as a positive control. High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) was used to determine the primary polyphenols in HPE. Hematoxylin & Eosin (H&E) staining was used to evaluate pathological conditions of the skeletal muscle, liver, and aorta vessels in each group. The levels of serum and intestinal tissue oxidative stress, tumor necrosis factor α (TNF-α), and inflammatory interleukin-6 (IL-6) were also assessed. Western blotting was used to evaluate protein expression levels in the associated molecular pathway. Volatile organic compounds (VOCs) from colon contents were determined using headspace-gas chromatography-ion mobility chromatography. Our results showed that supplementation with 300 mg HPE/kg body weight over four weeks significantly improved total cholesterol (TC), total triglyceride (TG), insulin, and lipopolysaccharide (LPS) levels in diabetic rats (p < 0.01). The lesions of skeletal muscle, liver, and aorta in diabetic rats were significantly improved. HPE supplementation also significantly downregulated the inflammatory factors (IL-6, TNF-α, and MCP-1) in the liver of diabetic rats via the SIRT1/AMPK/NF-κB signaling pathway. Furthermore, HPE significantly reduced insulin resistance in T2D rats by upregulating the phosphorylation of glucose absorption protein (GLUT4) and insulin resistance-associated proteins, p-IRS1, p-AKT, and p-PI3K, in the rat liver (p < 0.01). The findings show that HPE could also alleviate aortic injury by activating SIRT1 and regulating the NF-κB and Wnt2/β-catenin signaling pathways. Overall, the results of this study suggest that both HPE and MF have similar inhibitory effects on T2D in rats and that HPE could be used as a functional food component in the adjuvant treatment of T2D.

Hyperoside attenuates neuroinflammation, cognitive impairment and oxidative stress via suppressing TNF-α/NF-κB/caspase-3 signaling in type 2 diabetes rats

OBJECTIVES

Literature findings have instituted the role of hyperglycemia-induced oxidative stress and inflammation in the pathogenesis of cognitive derangement in diabetes mellitus (DM). Hyperoside (HYP) is a flavanone glycoside reported to possess diverse pharmacological benefits such as antioxidant and anti-inflammatory properties. The study explored whether HYP could mitigate DM-induced cognitive dysfunction and further elucidate on potential molecular mechanism in rats.

METHODS

Streptozotocin/high-fat diet-induced diabetic rats were treated orally with HYP (50, 200 and 400 mg/kg/day) for six consecutive weeks. The blood glucose and serum insulin levels, Morris water maze test, intraperitoneal glucose tolerance test, and brain acetylcholinesterase (AChE) activity were determined. The brain expression of inflammatory nuclear factor-kappa B (NF-κB), tumour necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), as well as superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), total antioxidant capacity (TAC), malondialdehyde (MDA), lipid profile and caspase-3 activity were estimated.

RESULTS

DM evoked hyperlipidemia, hypoinsulinemia, cognitive dysfunction by markedly increased AChE and reduction in learning and memory capacity. Brain activities of SOD and CAT, and levels of TAC and GSH were considerably depressed, whereas levels of IL-1β, IL-6, TNF-α, NF-κB, caspase-3 and MDA were prominently increased. Interestingly, the HYP treatment dose-dependently abrogated the altered cognitive and biochemical parameters.

DISCUSSION

The results suggested that hyperoside prevents DM-induced cognitive dysfunction, neuroinflammation and oxidative stress via antioxidant, anti-inflammatory and antiapoptotic mechanisms in rats.

Effects of Regular Exercise on Diabetes-Induced Memory Deficits and Biochemical Parameters in Male Rats

The main objective of current work was to determine the effects of treadmill-running and swimming exercise on passive avoidance learning (PAL) and blood biochemical parameters in rats with streptozotocin (STZ)-induced diabetes. Male Wistar rats were divided into the following 6 groups (N = 6-8 per group): CON, healthy rats without exercise (N = 8); STZ, diabetic rats without exercise (N = 8); CON-SE, healthy rats subjected to swimming exercise (2 months; N = 6); STZ-SE, diabetic rats subjected to swimming exercise (2 months; N = 7); CON-TE, healthy rats subjected to treadmill exercise (2 months; N = 8); STZ-TE, diabetic rats subjected to treadmill exercise (2 months; N = 8). Diabetes was induced by a single intraperitoneal injection of 50 mg/kg STZ. Our results showed that STZ decreased the step-through latency in the retention test (STLr) and increased the time spent in the dark compartment (TDC) when compared with the CON group. However, treadmill-running and swimming exercise in STZ-treated rats increased the STLr and decreased the TDC when compared with STZ-treated rats without exercise in PAL. Blood low-density lipoprotein (LDL) and triglyceride (TG) levels in the STZ group were significantly higher than those in the CON group, whereas plasma total antioxidant capacity (TAC) and levels of catalase (CAT) and glutathione peroxidase (GPx) were lower in the STZ group compared with the CON group. The levels of LDL and TG decreased and the levels of TAC, CAT, and GPx increased in the exercise groups in comparison with the STZ group. The present results indicate that regular exercise enhances learning and memory in diabetic rats and that these effects may occur through activation of the antioxidant system.

Hawthorn (Crataegus spp.): An Updated Overview on Its Beneficial Properties

Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to growing requests for natural and sustainable eco-compatible remedies for pathological conditions with beneficial health effects that are able to support/supplement a daily diet or to support and/or replace conventional pharmacological therapy. The main requests for these products are: safety, minimum adverse unwanted effects, better efficacy, greater bioavailability, and lower cost when compared with synthetic medications available on the market. One of these popular herbs is hawthorn (Crataegus spp.), belonging to the Rosaceae family, with about 280 species present in Europe, North Africa, West Asia, and North America. Various parts of this herb, including the berries, flowers, and leaves, are rich in nutrients and beneficial bioactive compounds. Its chemical composition has been reported to have many health benefits, including medicinal and nutraceutical properties. Accordingly, the present review gives a snapshot of the in vitro and in vivo therapeutic potential of this herb on human health.

The effects of aqueous extract of Origanum vulgare on learning and memory in male rats

Introduction: The effectiveness of antioxidants on learning and memory improvement has been shown, previously. Due to the high level of antioxidants, available in Origanum vulgare, the present experiment aimed to examine the effect of aqueous extract of O. vulgare on passive avoidance learning (PAL) in male Wistar rats. Methods: This study was performed on 30 male Wistar rats weighing 250 to 290 g. The rats were randomly assigned into five groups (n=6), as follows: the control, sham (saline), and three groups treated with different doses of O. vulgare extract (150, 250, and 350 mg/kg). The saline or extract was administered via daily oral gavage for 14 days. The groups were then subjected to the passive avoidance task, and their behaviors were recorded. The rats’ locomotor activity was also measured using the open field test. Results: The number of trials to acquisition was significantly lower in the "O. vulgare (350 mg/ kg)" group than the control group. The step-through latency and the time spent in the dark compartment in the retention test, was significantly higher and lower in the "O. vulgare (250 and 350 mg/kg)" groups than the control group, respectively. No significant differences were found in the distances traveled among the experimental groups in the open field test. Conclusion: Aqueous extract of O. vulgare can enhance learning and memory. The high levels of antioxidants in O. vulgare extract may be responsible for its effectiveness in learning and memory.

The protective and therapeutic effects of vinpocetine, a PDE1 inhibitor, on oxidative stress and learning and memory impairment induced by an intracerebroventricular (ICV) injection of amyloid beta (aβ) peptide

Alzheimer's disease (AD) is a neurodegenerative disease leading to cognitive and memory impairment. This study aimed at investigating the therapeutic and preserving effects of vinpocetine on amyloid beta (Aβ)-induced rat model of AD. Sixty male adult Wistar rats were randomly divided into 6 groups (n = 10 per group) as follows: 1; control, 2; sham, 3; Aβ, 4; pre-treatment (vinpocetine + Aβ): oral gavage administration of vinpocetine at 4 mg/kg for 30 days followed by intracerebroventricular (ICV) injection of Aβ, 5; treatment (Aβ + vinpocetine): Aβ ICV injection followed by vinpocetine administration for 30 days, 6; pre-treatment + treatment (vinpocetine + Aβ + vinpocetine): vinpocetine administration for 30 days before and 30 days after AD induction. Following treatments, the animals' learning and memory were investigated using passive avoidance learning (PAL) task, Morris water maze (MWM), and novel object recognition (NOR) tests. The results demonstrated that Aβ significantly enhanced escape latency and the distance traveled in the MWM, decreased step-through latency, and increased time spent in the dark compartment in PAL. Vinpocetine ameliorated the Aβ-infused memory deficits in both MWM and PAL tests. Administration of vinpocetine in the Aβ rats increased the discrimination index of the NOR test. It also significantly diminished the nitric oxide and malondialdehyde levels and restored the reduced glutathione (GSH) levels. Vinpocetine can improve memory and learning impairment following Aβ infusion due to its different properties, including antioxidant effects, which indicates that vinpocetine administration can lead to the amelioration of cognitive dysfunction in AD.

Effect of Crataegus extract supplementation on diabetes induced memory deficits and serum biochemical parameters in male rats

This study was undertaken to investigate the Crataegus extract (CE) eff ;ects on diabetes-induced memory deficit in passive avoidance learning (PAL), blood glucose, and lipid profile panel. Male Wistar rats were divided into five groups: Control (CTRL); Diabetic (DM); and Diabetic animals treated with three doses of CE (100, 300 and 1000 mg/kg) (DM + CE). Streptozotocin (STZ)-induced diabetic rats (50 mg/kg, ip) were orally administrated with CE once a day for 2 weeks. After 2 weeks, PAL task was used to evaluate the passive avoidance learning and memory. At the end of experiment, the level of plasma glucose, triglycerides (TG), cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were determined. Our results showed that the step-through latency (STLr) in diabetic animals was less than the control group (P = 0.0009). Crataegus (300 mg) increased STLr in diabetic animals (P = 0.0418). Diabetic animals spent more time in the dark compartment (TDC) (P = 0.0009). Crataegus (300 and 1000 mg) decreased TDC in diabetic animals (P = 0.0175). Crataegus (100 and 300 mg) decreased blood glucose in diabetic animals (P < 0.001). TG and Cholesterol concentration increased in diabetic animals in comparison with control (P < 0.05). CE (100 and 300 mg) reduced the cholesterol concentration in diabetic animals (P < 0.001). There was no significant difference in the case of LDL among the experimental groups (P > 0.05). CE (1000 mg) increased HDL in diabetic animals (P < 0.05). Our findings demonstrated that CE had the hypolipidemic and hypoglycemic effects and lead to memory improvement in STZ-induced diabetes.

Circular RNAs in β-cell function and type 2 diabetes-related complications: a potential diagnostic and therapeutic approach

Recent investigations have indicated that altered expression of non-coding RNAs (ncRNAs) could be associated with human diseases such as type 2 diabetes (T2D). Circular RNAs (circRNAs) are a new discovered class of ncRNAs with unique structural characteristics that involved in several molecular and cellular functions. Exploring of the circulating circRNAs as a reliable non-invasive biomarker for monitoring and diagnosing of human diseases has grown significantly. However, the molecular functions and clinical relevance of circRNAs are not yet well clarified in T2D. Accordingly, in this review, the involvement of circRNAs in the β-cell function and T2D-related complications is highlighted. The study also shed light on the possibility of using circRNAs as a biomarker for T2D diagnosis.

Cognitive Dysfunction in Type 1 Diabetes Mellitus

CONTEXT

We have summarized key studies assessing the epidemiology, mechanisms, and consequences of cognitive dysfunction (CD) in type 1 diabetes.

EVIDENCE SYNTHESIS

In a number of studies, the severity of CD in type 1 diabetes was affected by the age of onset and duration, and the presence of proliferative retinopathy and autonomic neuropathy. Diabetes-related CD has been observed, not only in adults, but also in children and adolescents. Most neuroimaging studies of patients with type 1 diabetes did not show any differences in whole brain volumes; however, they did reveal selective deficits in gray matter volume or density within the frontal, posterior, and temporal cortex and subcortical gray matter. Studies of middle-age adults with long-standing type 1 diabetes using diffusion tensor imaging have demonstrated partial lesions in the white matter and decreased fractional anisotropy in posterior brain regions. The mechanisms underlying diabetes-related CD are very complex and include factors related to diabetes per se and to diabetes-related cardiovascular disease and microvascular dysfunction, including chronic hyperglycemia, hypoglycemia, macro- and microvascular disease, and increased inflammatory cytokine expression. These mechanisms might contribute to the development and progression of both vascular dementia and Alzheimer disease.

CONCLUSIONS

Higher rates of CD and faster progression in type 1 diabetes can be explained by both the direct effects of altered glucose metabolism on the brain and diabetes-related cardiovascular disease. Because the presence and progression of CD significantly worsens the quality of life of patients with diabetes, further multidisciplinary studies incorporating the recent progress in both neuroimaging and type 1 diabetes management are warranted to investigate this problem.

Effect of coenzyme Q10 supplementation on diabetes induced memory deficits in rats

The main objective of current work was to determine the effects of low and high dose supplementation with coenzyme Q10 (CoQ10) on spatial learning and memory in rats with streptozotocin (STZ)-induced diabetes. Male Wistar rats (weighing 220 ± 10) were randomly divided into six groups: (i) Control (Con, n = 8); (ii) Control+ Low dose of CoQ10 (100 mg/kg) (CLD, n = 10); (iii) Control+ high dose of CoQ10 (600 mg/kg) (CHD, n = 10); (iv) Diabetic (D, n = 10); (v) Diabetic + Low dose of CoQ10 (100 mg/kg) (DLD, n = 10); (vi) Diabetic + high dose of CoQ10 (600 mg/kg) (DHD, n = 10). Diabetes was induced by a single intraperitoneal injection of 50 mg/kg STZ. CoQ10 was administered intragastrically by gavage once a day for 90 days. After 90 days, Morris water maze (MWM) task was used to evaluate the spatial learning and memory in rats. Diabetic animals showed a slower rate of acquisition with respect to the control animals [F (1, 51) = 92.81, P < 0.0001, two-way ANOVA]. High dose (but no low dose) supplementation with CoQ10 could attenuate deteriorative effect of diabetes on memory acquisition. Diabetic animals which received CoQ10 (600 mg/kg) show a considerable decrease in escape latency and traveled distance compared to diabetic animals (p < 0.05, two-way ANOVA,). The present study has shown that low dose supplementation with CoQ10 in diabetic rats failed to improve deficits in cognitive function but high dose supplementation with CoQ10 reversed diabetes-related declines in spatial learning.

Effect of a hydro-alcoholic extract of Melissa officinalis on passive avoidance learning and memory

Introduction: Melissa officinalis (MO) or lemon balm is traditionally used as a sedative and anti-spasm herbal medicine. There is also evidence that this plant has effects on learning and memory. This study examined the effect of a hydro-alcoholic extract of MO on passive avoidance learning (PAL) and memory in male rats. Methods: A total of 40 adult male Wistar rats were randomly distributed into four groups (200 to 220 g; n = 10 per group); three dose groups (50, 100, and 200 mg/kg of the hydro-alcoholic extract of MO) and vehicle control (saline) group. Saline or doses of extract were administered daily for 14 days by oral gavage. The rats were trained to enter the shuttle box to record their behavior in the PAL task. A retrieval test was performed 24 hours following training. Results: A significant difference was seen in performance among MO groups and the control. MO administered animals had a decreased number of acquisition trials (P < 0.05). In the retention task, MO administered animals had an increased step-through latency (SLT) (P < 0.01), and a decreased latency in the dark compartment (P < 0.001) compared to the control group. Conclusion: The results of the study show that MO can improve learning and memory in the PAL task. Further investigation is needed to enhance our understanding of the neurobiological mechanisms of the MO extract and its effects on learning and memory.

Tempol improves oxidant/antioxidant parameters in testicular tissues of diabetic rats

AIMS

Oxidative stress induced by diabetes mellitus (DM) is considered as one of the main causes of infertility in diabetic patients. The aim of the present study was to assess the effect of Tempol - as a synthetic antioxidant- on the testis oxidative stress and sperm parameters in type 2 diabetic (T2D) rats.

MAIN METHODS

Twenty male Wistar rats were divided into 4 groups. Control groups (C) and diabetic groups (D); the control and diabetic groups received Tempol (100 mg/kg) for one month. Sperm parameters and oxidative stress biomarkers were evaluated in testicular tissue.

KEY FINDINGS

The results demonstrated that administration of Tempol in diabetic rats improved sperm motility and viability and decreased the count of abnormal sperms. Also Tempol decreased the fasting blood sugar (FBS) and lipid peroxidation (LPO). In addition, Tempol significantly increased total antioxidant capacity (TAC) levels in testis tissue of T2D rats. Histopathological changes were also improved in the diabetic treated group.

SIGNIFICANCE

Taken together, the results indicated that Tempol improved fertility parameters in a diabetic rat through reducing oxidative stress.

Hawthorn Polyphenol Extract Inhibits UVB-Induced Skin Photoaging by Regulating MMP Expression and Type I Procollagen Production in Mice

Ultraviolet (UV) B radiation can cause skin aging by increasing matrix metalloproteinase (MMP) production and collagen degradation, leading to the formation of wrinkles. This study investigated whether hawthorn polyphenol extract (HPE) protects against UVB-induced skin photoaging using HaCaT human keratinocytes, normal human dermal fibroblasts (HDFs), and mice. Analysis of the phenol composition of HPE by high-performance liquid chromatography-mass spectrometry showed that chlorogenic acid (13.5%), procyanidin B2 (19.2%), and epicatechin (18.8%) collectively accounted for 51.4% of total phenol content and represent the active ingredients of hawthorn fruit. A cell viability assay revealed that HPE treatment promoted cell proliferation in HaCaT cells and HDFs. On the other hand, MMP-1 and type I procollagen production was decreased and increased, respectively, in UVB-exposed cells treated with HPE as compared with those without treatment, as determined by enzyme-linked immunosorbent assay. Hematoxylin and eosin and Weigert staining of dermal tissue specimens from mice demonstrated that HPE also reversed UVB-induced epidermal thickening and dermal damage. The increase in production of reactive oxygen species and decrease in antioxidant enzyme activity as well as the increase in nuclear factor-κB activation and mitogen-activated protein kinase phosphorylation induced by UVB irradiation were reversed by HPE (100 or 300 mg/kg body weight), which also suppressed MMP expression and stimulated the production of type I procollagen in the dorsal skin of UVB-irradiated mice. These results suggest that HPE is a natural product that can prevent UVB radiation-induced skin photoaging.

Cerium Oxide Nanoparticle Effects on Paraoxonase-1 Activity and Oxidative Toxic Stress Induced by Malathion: A Potential Antioxidant Compound, Yes or No?

Cerium oxide nanoparticles (CeNPs) are one of the most widely used and important nanoparticles in addition to possessing strong antioxidative properties and inhibiting free radicals. Paraoxonase-1 (PON1) is one of the enzymes that protect the body against damage caused by oxidative stress. The purpose of this study was to investigate the effect of CeNPs on the activity of PON1 as well as biomarkers of oxidative stress in the toxicity of malathion. 48 Albino Wistar male rats with weight range of 180-250 g were randomly divided into 8 groups, Group 1: healthy control, injection of normal saline, Group 2: administration by the malathion 100 mg/kg/day, Group 3: treated with CeNPs 15 mg/kg/day, Group 4: treated with CeNPs 30 mg/kg/day, Group 5: combination of malathion with dose of 100 mg/kg/day and CeNPs 15 mg/kg, Group 6: combination of malathion with dose of 100 mg/kg/day and CeNPs 30 mg/kg for 14 days and 24 h after termination of treatment period, serum and liver tissue samples were collected from all rats. Biochemical test of PON1 activity, oxidative stress biomarkers including total antioxidant capacity (TAC), lipid peroxidation (LPO), total thiol groups (TTG), were carried out. Malathion reduced plasma TTG levels, TAC and increased LPO in malathion group. However, CeNPs increased TTG, TAC and reduced PON1 activity. Results showed that CeNPs alone had antioxidant properties while with malathion it shows different properties.

Virgin coconut oil (VCO) by normalizing NLRP3 inflammasome showed potential neuroprotective effects in Amyloid-β induced toxicity and high-fat diet fed rat

Both dyslipidemia and Alzheimer disease (AD) are associated with aging. In this study, the effects of virgin coconut oil (VCO) on inflammasome and oxidative stress in Alzheimer's model (receiving Amyloid-β (Aβ)) and high-fat diet (HFD) model were determined. A total of 120 male Wistar rats, were divided into 12 groups (n = 10), including; healthy control, sham surgery, sham surgery receiving normal saline, HFD, HFD + 8% VCO, HFD + 10% VCO, Aβ received rats, Aβ + 8%VCO, Aβ + 10%VCO, HFD + Aβ, HFD + Aβ+8%VCO, and HFD + Aβ + 10%VCO. Following memory and learning tests, blood sample prepared from the heart and hippocampus of rats in each group was kept at -70 °C for genes expression, oxidative stress, and biochemical tests. Aβ and HFD significantly impaired memory and learning by activating of both NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and oxidative stress (p<0.05), while treatment with both 8 and 10% VCO normalized inflammasome genes expression and oxidative stress (p<0.05). The Congo Red, Cresyl Violet staining and immunohistochemistry (IHC) test revealed that VCO improved hippocampus histological changes, reduced Aβ plaques and phosphorylated Tau. High-fat diet has exacerbated the effects of Aβ, while VCO showed potential neuroprotective effect.

Silymarin ameliorates expression of urotensin II (U-II) and its receptor (UTR) and attenuates toxic oxidative stress in the heart of rats with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD). Urotensin II ((U-II)) and its receptor (UTR) are involved in the progression of CVD through enhancement in the production of reactive oxygen species (ROS). Since silymarin (SMN) is a natural agent with anti-diabetic effects, this study aimed to investigate the antioxidant potency of SMN on the expression of (U-II)/UTR system and oxidative stress status in the heart of type 2 diabetic rats. Thirty-six male Wistar rats were randomly divided into six groups (n = 6). Control and diabetic groups treated with or without SMN (60 and 120 mg/kg/day) for 2 months. Fasting blood sugar (FBS), insulin, lipid profile, creatine kinase-MB ((CK-MB)), lactate dehydrogenase (LDH) and markers of oxidative stress were measured by spectrophotometric methods while (U-II) and UTR gene expression was determined by qPCR method. SMN significantly reduced the FBS level, increased the concentration of insulin and improved HOMA-IR. SMN prevented diabetes-induced weight loss, and attenuated the increased levels of total oxidative status (TOS), malondialdehyde (MDA), and nitric oxide (NO). Diabetes-induced reduction of total thiol molecules content (TTM) was normalized to the normal level in SMN treated rats. SMN significantly modulated serum lipid profile, reduced the expression of (U-II) and UTR in the heart, and improved histopathological changes in the heart tissues. Therefore, the current study indicated that SMN ameliorated unpleasant diabetic characteristics via down-regulation of (U-II) and UTR gene expression and modulation of oxidative stress in the heart tissue of type 2 diabetic rats.