Esculeoside A Decreases Diabetic Cardiomyopathy in Streptozotocin-Treated Rats by Attenuating Oxidative Stress, Inflammation, Fibrosis, and Apoptosis: Impressive Role of Nrf2

Exploring the anti-inflammatory and antiapoptotic properties of phloroglucinol on pancreatic cells in diabetic models: In silico and in vivo study

Pancreatic cell damage in diabetes mellitus is closely linked to inflammation and apoptosis. This study aimed to investigate the protective effects of phloroglucinol on pancreatic cells in a streptozotocin-induced diabetic model by assessing its anti- inflammatory and anti-apoptotic mechanisms. Phloroglucinol ligand and the structures of Bax, Bcl-2, and caspase-3 proteins were sourced from the PubChem database. Molecular docking was performed using Autodock Tools and docking results were analyzed with PyRx software. In addition, during the in vivo study, the BALB/c mice were grouped into four categories: healthy control, untreated streptozotocin-induced diabetic, and streptozotocin-induced diabetic treated with two doses of oral phloroglucinol at 100 mg/kg and 200 mg/kg body weight. After 28 days, pancreatic tissues were collected for flow cytometric analysis of NF-κB, IL-6, TNF-α, and apoptotic markers (Bax, Bcl-2, and caspase-3). The docking simulations revealed specific binding interactions: phloroglucinol interacted with Bcl-2 via amino acid residues of ALA90 and TYR139, with Bax via ALA42, LEU45, ALA46, LEU47, PRO130, and ILE133, and with caspase-3 through ARG64, SER120, GLN161, CYS163, and ARG207. The binding affinities for Bax, Bcl-2, and caspase-3 were -5.0, -4.7, and -4.9 kcal/mol, respectively. In vivo, results showed that streptozotocin significantly elevated inflammatory cytokines NF-κB, TNF-α, and IL-6, along with apoptotic markers in pancreatic cells (p<0.05) compared to healthy controls. Phloroglucinol administration at 200 mg/kg significantly reduced TNF-α, NF-κB and IL- 6 levels. Phloroglucinol also prevented streptozotocin-induced pancreatic cell damage through anti-apoptotic effects by downregulating Bax and caspase-3 and upregulating Bcl-2. These findings suggest that phloroglucinol may offer protective benefits in diabetic conditions by modulating apoptotic and inflammatory pathways.

Therapeutic potential of finerenone for diabetic cardiomyopathy: focus on the mechanisms

Diabetic cardiomyopathy (DCM) is a kind of myocardial disease that occurs in diabetes patients and cannot be explained by hypertensive heart disease, coronary atherosclerotic heart disease and other heart diseases. Its pathogenesis may be closely related to programmed cell death, oxidative stress, intestinal microbes and micro-RNAs. The excessive activation of mineralocorticoid receptors (MR) in DCM can cause damage to the heart and kidneys. The third-generation non-steroidal mineralocorticoid receptor antagonist (MRA), finerenone, can effectively block MR, thus playing a role in protecting the heart and kidneys. This review mainly introduces the classification of MRA, and the mechanism of action, applications and limitations of finerenone in DCM, in order to provide reference for the study of treatment plans for DCM patients.

Comparative Efficacy of Low-Carbohydrate and Ketogenic Diets on Diabetic Retinopathy and Oxidative Stress in High-Fat Diet-Induced Diabetic Rats

This study examined the effect of a low-carbohydrate diet (LCD) and a low-carbohydrate ketogenic diet (LCKD) on diabetic retinopathy in high-fat diet-induced diabetes mellitus in rats and studied the mechanisms of action. Rats were divided into four groups: the Control group, which was fed a normal diet for 16 weeks; the HFD group, which was fed a high-fat diet (HFD) for the first 8 weeks and then switched to a normal diet for 8 weeks; the HFD+LCD group, fed a HFD for 8 weeks followed by an LCD for 8 weeks, and the HFD+LCKD group, which was fed a HFD for 8 weeks followed by an LCKD for 8 more weeks. Both the LCD and the LCKD effectively reduced the final body and total fat weights and decreased fasting serum levels of glucose, insulin, hemoglobin A1 (HbA1C), triglycerides, cholesterol, and LDL-c. They also reduced the levels of malondialdehyde (MDA), tumor necrosis factor-α, vascular endothelial factor, caspapse-3, and bax. In the HFD rats, we found increased serum levels of β-Hydroxybutyrate and upregulated expression of Bcl2, glutathione, superoxide dismutase, and hemeoxygenase-1. Moreover, the LCD and LCKD significantly reduced mRNA levels of Kelch-like ECH-associated protein 1 (Keap1) and enhanced mRNA and nuclear concentrations of nuclear factor erythroid factor 2 (Nrf2). All these effects were associated with improved layers of the retina in the HFD - LCD and HFD + LCKD rats but not in HFD animals. The impact of the LCKD was always more profound on all measured parameters and on improving the structure of the retina compared to the LCD. In conclusion, the LCKD is superior to the LCD in preventing diabetic retinopathy in HFD-fed rats. Mechanistically, our results suggest that the hypoglycemic and hypolipidemic conditions and the Nrf2-dependent antioxidant and anti-inflammatory effects may be involved in the preventative effects of the LCD and LCKD.

Evolving Strategies for Use of Phytochemicals in Prevention and Long-Term Management of Cardiovascular Diseases (CVD)

This report describes major pathomechanisms of disease in which the dysregulation of host inflammatory processes is a major factor, with cardiovascular disease (CVD) as a primary model, and reviews strategies for countermeasures based on synergistic interaction between various agents, including drugs and generally regarded as safe (GRAS) natural medical material (NMM), such as Ginkgo biloba, spice phytochemicals, and fruit seed flavonoids. The 15 well-defined CVD classes are explored with particular emphasis on the extent to which oxidative stressors and associated ischemia-reperfusion tissue injury contribute to major symptoms. The four major categories of pharmaceutical agents used for the prevention of and therapy for CVD: statins, beta blockers (β-blockers), blood thinners (anticoagulants), and aspirin, are presented along with their adverse effects. Analyses of major cellular and molecular features of drug- and NMM-mediated cardioprotective processes are provided in the context of their development for human clinical application. Future directions of the evolving research described here will be particularly focused on the characterization and manipulation of calcium- and calcineurin-mediated cascades of signaling from cell surface receptors on cardiovascular and immune cells to the nucleus, with the emergence of both protective and pathological epigenetic features that may be modulated by synergistically-acting combinations of drugs and phytochemicals in which phytochemicals interact with cells to promote signaling that reduces the effective dosage and thus (often) toxicity of drugs.

Impact of various dietary lipids on amelioration of biomarkers linked to metabolic syndrome in both healthy and diabetic Wistar rats

BACKGROUND

The present study was designed to investigate the influence of different dietary lipids (sheep's fat, olive oil, coconut oil, and corn oil) on specific biomarkers associated with metabolic syndrome in both healthy and diabetic rats.

METHODS

The study designed for 45 days, utilized a male diabetic wistar rat (body weight, 180-220 g) model induced by streptozotocin (45 mg/kg bw). The rats were divided into two sections: five non-diabetic and five diabetic groups, each containing six rats. The first group in each section serving as the control, received a standard diet. Both non-diabetic or diabetic groups, were provided with a standard diet enriched with 15% sheep fat, 15% coconut oil, 15% olive oil, and 15% corn oil, respectively for a duration of 45 days.

RESULTS

Post-supplementation, both healthy and diabetic control rats exhibited a higher food intake compared to rats supplemented with lipid diet; notably food intake was higher in diabetic control than healthy control. However, rats fed with coconut oil, olive oil and sheep fat showed weight gain at the end of the experiment, in both healthy and diabetic groups. Coconut oil supplementation significantly (p ≤ 0.05) increased HDL-C and total cholesterol level in diabetic groups compared to healthy group, it was confirmed by an increased PPAR-α and ABCA-1 protein level. Olive oil significantly decreased triglyceride, total cholesterol, and LDL-C levels in diabetic rats when compared to sheep fat or coconut oil. Corn oil significantly decreased fasting glucose, total cholesterol and LDL-C levels compared to all other groups. Corn and olive oil supplemented normal groups, found with significant increase in hepatic glucose-lipid oxidative metabolism associated protein, like FGF-21, MSH, ABCA-1, PPAR-γ and decreased lipogenesis proteins like, SREBP and PPAR-α levels. In contrast, sheep grease and coconut oil increased SREBP and PPAR-α expression in both normal and diabetic groups. Most notably, normal and diabetic groups pretreated with sheep grease resulted in increased inflammatory (MCP-1, IL-1β, TLR-4, TNF-α), and oxidative stress markers (LPO, GSH, GPx, SOD and CAT) linked with metabolic complications.

CONCLUSION

The combination or alternative use of olive oil and corn oil in daily diet may play a significant role in preventing proinflammatory condition associated with insulin resistance and cardiovascular diseases.

Nrf-2-dependent antioxidant and anti-inflammatory effects underlie the protective effect of esculeoside A against retinal damage in streptozotocin-induced diabetic rats

Esculeoside A (ESA) is a tomato-derived glycoside with antioxidant and anti-inflammatory properties. The protective effect of ESA against diabetic retinopathy is not well-investigated and was the core objective of this study. In addition, we tested if such protection involves the activation of Nrf2 signaling. Type 1 diabetes mellitus (T1DM) was induced in adult Wistar male rats by an intraperitoneal injection of streptozotocin (65 mg/kg). Non-diabetic and T1DM rats were divided into two subgroup groups given either the vehicle or ESA (100 mg)/kg. An additional T1DM group was given ESA (100 mg/kg) and an Nrf2 inhibitor (2 mg/kg) (n=8 rats/group). Treatments continued for 12 weeks. In this study, according to the histological features, ESA improved the structure of ganglionic cells and increased the number of cells of the inner nuclear and plexiform layers in the retinas of T1DM rats. Concomitantly, it reduced the retina levels of malondialdehyde (lipid peroxides), vascular endothelial growth factor, interleukin-6, tumor necrosis factor-α, Bax, and caspase-3. In the retinas of the control and diabetic rats, ESA boosted the levels of total glutathione, superoxide dismutase, heme-oxygenase-1, and Bcl2, reduced the mRNA levels of REDD1, and enhanced cytoplasmic and nuclear levels of Nrf2. However, ESA failed to alter the mRNA levels of Nrf2 and keap1, protein levels of keap1, plasma glucose, plasma insulin, serum triglycerides, cholesterol, and LDL-c in both the control and T1DM rats. In conclusion, ESA alleviates retinopathy in T1DM rats by suppressing REDD1-associated degradation and inhibiting the Nrf2/antioxidant axis.

Cadmium exposure exacerbates kidney damage by inhibiting autophagy in diabetic rats

The incidence of diabetes mellitus (DM) is gradually increasing, making it a widespread global health concern. Cadmium (Cd) is a common toxic heavy metal in the environment, and cadmium exposure may be associated with diabetic nephropathy (DN). However, the mechanism of Cd-induced DN remains unclear. In this study, we aimed to determine the effect of cadmium on diabetic kidney injury and the underlying mechanism in diabetic rats and a renal tubular epithelial cell line (NRK-52E cells). Our results could provide novel insights on the nephrotoxic mechanism of cadmium. HE, PAS, and Masson staining were used to observe pathological renal injury. COL-I, COL-IV, CTSB, and CTSD protein levels were detected by immunohistochemistry and western blotting. Immunofluorescence was used to detect the fluorescence intensity of p62 and LC3 proteins in kidney tissue. TEM was used to observe the ultrastructure of mitochondria and number of autophagosomes. After cadmium exposure, DM rats showed a dramatic decrease in body weight compared to the unexposed DM group. Relative kidney weight showed a contrasting trend after cadmium exposure. Urinary microalbumin/creatinine significantly increased in normal and DM rats after cadmium exposure. However, the trend was clearer in the DM groups than in the control groups. Endogenous creatinine clearance exhibited a contrasting trend. After cadmium exposure in DM rats, MDA content significantly increased and GSH, CAT, SOD, and GSH-PX activation reduced compared to normal controls. Pathological damage was more pronounced, and the expression of autophagy related proteins and apoptosis and fibrosis proteins was significantly higher in vivo and vitro in the cadmium-exposed groups than in unexposed controls. Further, lysosomal protein levels were lower, and ROS content and autophagosome count significantly higher in the cadmium exposed groups compared to the unexposed controls. Therefore, Cadmium exposure aggravates diabetic kidney injury via autophagy inhibition.