Effects of ellagic acid in the testes of streptozotocin induced diabetic rats

Ellagic acid as potential therapeutic compound for diabetes and its complications: a systematic review from bench to bed

Diabetes mellitus (DM) is a worldwide-concerning disease with a rising prevalence. There are many ongoing studies aimed at finding new and effective treatments. Ellagic acid (EA) is a natural polyphenolic compound abundant in certain fruits and vegetables. It is the objective of this investigation to assess the effectiveness and preventive mechanisms of EA on DM and associated complications. This systematic review used PubMed, Scopus, and Google Scholar as search databases using a predetermined protocol from inception to June 2024. We assessed all related English studies, including in vitro, in vivo, and clinical trials. EA counteracted DM and its complications by diminishing inflammation, oxidative stress, hyperglycemia, apoptosis, insulin resistance, obesity, lipid profile, and histopathological alterations. Several mechanisms contributed to the anti-diabetic effect of EA, the most significant being the upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), peroxisome proliferator-activated receptor gamma (PPAR-γ), protein kinase B, and downregulation of nuclear factor-kappa-B (NF-κB) gene expression. EA also revealed protective effects against diabetes complications, such as diabetic-induced hepatic damage, testicular damage, endothelial dysfunction, muscle dysfunction, retinopathy, nephropathy, cardiomyopathy, neuropathy, and behavioral deficit. Administration of EA could have various protective effects in preventing, treating, and alleviating DM and its complications. Although it could be considered a cost-effective, safe, and accessible treatment, to fully establish the effectiveness of EA as a medication for DM, it is crucial to conduct further well-designed studies.

Role of polyphenols in the management of diabetic complications

BACKGROUND

Diabetes Mellitus is an endocrine disorder that will affect, about 693 million adults by 2045 worldwide, (>50% increase from 2017). The conventional treatment of the disease, include the oral hypoglycemic drugs which are given in combination with other drugs and are known to possess various adverse effects like gastrointestinal disturbance, nausea, water retention etc. PURPOSE: Due to the urgent need of combating this disorder without side effects, the alternative and complementary therapies should be explored due to their natural origins and comparable safety. Herbal sources serve as new leads, due to the presence of phytoconstituents with potential therapeutic properties, efficacy and safety. In this review, we tried to summarise the polyphenolic phytoconstituents effective in the treatment of diabetic complications.

METHODS

A systematic literature search was conducted using 4 databases (Google scholar, Pubmed, Scopus, Embase) for the identification of relevant data. Search was performed using various key words such as "diabetes", "polyphenols", "marine sources","anti-diabetic polyphenols". The in vitro studies involving the cell lines used in diabetes and animal models were also considered for inclusion. Additional research papers were identified by reviewing abstracts, scrutinizing reference lists, and reviewing previously published review articles.

RESULTS

Polyphenols, a group of phytoconstituents are known worldwide for their tremendous antioxidant potential. So, various research groups have explored their mechanism and therapeutic value in diabetic complications, to improve the insulin sensitivity and glucose metabolism, in controlling the glycemic conditions.

CONCLUSION

Polyphenols exhibit effective therapeutic potential in managing diabetic complications through their multifaceted mechanism of action. They exhibit antioxidative, anti-inflammatory, and anti-glycemic properties, which collectively contribute to their beneficial effects in mitigating diabetic complications. Thus, the inclusion of polyphenols into the diet, may be cosidered as an approach of managing diabetes on long term basis. In this review, we have tried to identify polyphenols effective in diabetes and summarize their mechanism of action along with their potential, for the treatment of diabetic complications.

The Modulatory Bioeffects of Pomegranate (Punica granatum L.) Polyphenols on Metabolic Disorders: Understanding Their Preventive Role against Metabolic Syndrome

Modern research achievements support the health-promoting effects of natural products and diets rich in polyphenols. Pomegranate (PG) (Punica granatum L.) contains a considerable number of bioactive compounds that exert a broad spectrum of beneficial biological activities, including antimicrobial, antidiabetic, antiobesity, and atheroprotective properties. In this context, the reviewed literature shows that PG intake might reduce insulin resistance, cytokine levels, redox gene expression, blood pressure elevation, vascular injuries, and lipoprotein oxidative modifications. The lipid parameter corrective capabilities of PG-ellagitannins have also been extensively reported to be significantly effective in reducing hyperlipidemia (TC, LDL-C, VLDL-C, and TAGs), while increasing plasma HDL-C concentrations and improving the TC/HDL-C and LDL-C/HDL-C ratios. The health benefits of pomegranate consumption seem to be acheived through the amelioration of adipose tissue endocrine function, fatty acid utilization, GLUT receptor expression, paraoxonase activity enhancement, and the modulation of PPAR and NF-κB. While the results from animal experiments are promising, human findings published in this field are inconsistent and are still limited in several aspects. The present review aims to discuss and provide a critical analysis of PG's bioeffects on the components of metabolic syndrome, type-2 diabetes, obesity, and dyslipidemia, as well as on certain cardiovascular-related diseases. Additionally, a brief overview of the pharmacokinetic properties, safety, and bioavailability of PG-ellagitannins is included.

Evaluation of the effects of sinapic acid and ellagic acid on sciatic nerve in experimental diabetic rats by immunohistochemical and stereological methods

In our study, we aimed to examine the effects of sinapic acid and ellagic acid on neuropathy caused by diabetes in peripheral nerves. Fifty-six adult Wistar Albino rats Control, Diabetes, Diabetes+Sinapic Acid, Diabetes+Ellagic Acid, Diabetes+Sinapic Acid+Ellagic Acid, Sinapic Acid, Ellagic Acid and as Sinapic Acid+Ellagic Acid, they were randomly divided into eight groups(n:7). A single dose of 50 mg/kg streptozotocin(STZ) was administered intraperitoneally to the groups to be diagnosed with diabetes. Diabetes was accepted as blood glucose value of 250 mg/dL and above. Streptozotocin was given to the diabetes groups, 20 mg/kg/day intragastric Sinapic acid to the Sinapic acid groups, 50 mg/kg/day intragastric Ellagic acid to the Ellagic acid groups for 28 days. At the end of the experiment, 0.5 cm of the right sciatic nerve was removed. It was fixed in 10% formaldehyde. After histological follow-up, it was embedded in paraffin, 5 µm thick sections were taken. Immunohistochemical staining with Fibrinogen alpha, Laminin β-1 and Collagen IV antibodies and stereological evaluation was performed by Physical Dissector Combination method. Collagen IV was used in control, diabetes and treatment groups showed similar immunostaining. Fibrinogen alpha was observed to be increased in the vessel wall in the diabetes group, while the uptake was minimal in the control and treatment groups. While Laminin β-1 was increased in the diabetes group compared to the control group, immunostaining was observed in the treatment groups similar to the control group. It was observed that the total nerve area diabetes group decreased significantly compared to the control group, and the treatment groups, except for D+EA group were similar to the control group, but there was no statistically significant difference. The axon numbers in the diabetes group decreased significantly compared to the control group, and the treatment groups were similar to the control group, and there was no statistically significant difference (P > 0.05). It was determined that Sinapic Acid and Ellagic acid had positive effects on the nervous tissue in diabetic neuropathy.

Ellagic acid increases implantation rates with its antifibrotic effect in the rat model of intrauterine adhesion

Intrauterine adhesions (IUA) are defined as the adhesion of opposing endometrial tissue with dense fibrous adhesive bands within the uterine cavity. With the increase in cesarean sections and endometrial surgical procedures, intrauterine adhesions have become a problem with increasing incidence and decreasing implantation. The purpose of the study was to investigate the effect of ellagic acid (EA), a phenolic compound, on fibrosis in IUA model rats. Another goal of the study was to increase endometrial receptivity with EA. The groups in the study were planned as control, DMSO, EA, IUA, IUA+DMSO, and IUA+EA, with 8 Sprague Dawley rats in each group. EA was administered at a dose of 100 mg/kg/day for 35 days. At the end of the experiment, the uterine tissues of the rats were removed. Histochemical staining was used to validate the IUA model and determine the degree of fibrosis. The levels of some fibrosis-related genes and proteins in the obtained uterine tissues were evaluated. In addition, implantation rates were determined. In our findings, it was observed that the fibrotic structure was decreased in the treated IUA+EA group compared to the IUA group, while fibrotic improvement was supported by down-regulation of TGFβ1 activity and up-regulation of BMP7 activity. The increase in the expression of the endometrial marker LIF with EA treatment was consistent with the increase in implantation rates with treatment. As a result of the study, it can be said that EA applied as a treatment against IUA causes healing in uterine tissue by reducing fibrosis and increases implantation rates by increasing endometrial receptivity.

The Effects of N-acetylcysteine on Transient Receptor Potential Melastatin 2 Channels Activation and Expression in Testicular Tissue of Diabetic Rats

INTRODUCTION

Diabetes mellitus (DM) is a common, chronic metabolic disease that has harmful effects on many diverse tissues, including the testis. One of the ways of tissue damage is the modification of transient receptor potential melastatin 2 (TRPM2) channels by increased reactive oxygen species (ROS). In our study for the first time, it was aimed to investigate TRPM2 channel activation in testicular tissues of diabetic rats induced by streptozotosin (STZ) and to examine the efficacy of N-acetylcysteine (NAC) treatment, which is an antioxidant.

METHODS

In our study, 28 Wistar albino male rats aged 8-10 weeks were used, and animals were divided into four groups: control group, NAC group, DM group, and DM + NAC group. The experimental phase was designed as eight weeks. The malondialdehyde (MDA) level, which is an indicator for lipid peroxidation due to oxidative stress, was measured by the spectrophotometric method. The Tunel assay was used to determine apoptosis on testicular tissue. TRPM2 immunoreactivity was determined by the avidin-biotin-peroxidase complex method, and quantitative polymerase chain reaction (QPCR) was used to determine TRPM2 expression levels.

RESULTS

It was seen that MDA levels were significantly increased in the DM group and decreased after NAC treatment. Similarly, it was observed that apoptosis levels, which increased significantly in diabetic rats, decreased to the levels of the control group after treatment. It was seen that TRPM2 activation and expression levels were significantly decreased in the DM group.

CONCLUSION

 The results of this study show that NAC regulates TRPM2 activation in the testicular tissue of patients with diabetes and has tissue-protective properties.

Is losartan a promising agent for the treatment of type 1 diabetes-induced testicular germ cell apoptosis in rats?

BACKGROUND

Diabetes mellitus (DM) is common metabolic disease that poses a major risk to public health and fertility. Previous studies indicate that DM may cause male infertility by triggering oxidative stress and germ cell apoptosis in the testis. Due to the undesirable effects of known antidiabetic drugs, scientists have begun to investigate the use of alternative drugs to control infertility complications observed in men. In this context, present study aimed to investigate the possible antiapoptotic effect of losartan against DM-induced testicular germ cell apoptosis.

METHODS AND RESULTS

Expreimental DM model was induced by intraperitoneal injection of streptozocin (STZ, 55 mg/kg) to 28 rats, which were then randomly assigned to 4 groups; 1 mL saline solution was given to DM + saline group by oral gavage, 5 mg/kg/day oral losartan was given to DM + low-dose losartan, 20 mg/kg/day oral losartan was given to DM + mid-dose losartan and, 80 mg/kg/day oral losartan was given to DM + high-dose losartan group for 4 weeks. Bax, Bcl-2 and cleaved-Caspase 3 immunoexpression, terminal-deoxynucleotidyl transferase dutp nick end labeling (TUNEL), Annexin-V and Real Time PCR analyses performed to evaluate antiapoptotic effects of losartan on diabetic rats' testis. In addition, biochemical analyzes carried out to evaluate change in oxidative stress.

CONCLUSION

The results showed that losartan may have dose-related antiapoptotic effects on rats' testis via decreasing oxidative stress.

Ellagic acid attenuates muscle atrophy in STZ-induced diabetic mice

Diabetes is closely connected with skeletal muscle dysfunction. Ellagic acid (EA) possesses a variety of bio-effects and is applied to the improvement of diabetes. The purpose of this study was to explore the potential improvement effect and mechanisms of EA in streptozotocin (STZ)-induced diabetic muscle atrophy. The model of diabetic mice was established by intra-peritoneal STZ to evaluate treatment effect of EA (100 mg/kg/d for 8 weeks) on muscle atrophy. Our data exhibited that EA enhanced fiber size and weight of gastrocnemius, and promoted grip strength to relieve STZ-induced muscle lesions. In serum, the levels of Creatine kinase (CK), lactate dehydrogenase (LDH), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL) were inhibited, while high-density lipoprotein cholesterol (HDL) level was enhanced by EA treatment in diabetic mice. In gastrocnemius, EA decreased Atrogin-1 and MuRF-1 expressions to relieve STZ-induced muscle atrophy. Moreover, EA increased NRF-1 and PGC-1alpha expressions to alleviate mitochondrial disorder. Meanwhile, EA suppressed CHOP and GRP-87 levels to relieve ER stress. Lastly, EA inhibited BAX expressions and enhanced Bcl-2 expressions to mitigate apoptosis. In conclusion, EA is preventing the event of STZ-induced gastrocnemia by amelioration of mitochondrial dysfunction, ER stress and apoptosis, and could be used in the protection and therapeutic of muscle atrophy in diabetes.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.