Liver Dysfunction and Oxidative Stress in Streptozotocin-Induced Diabetic Rats: Protective Role of Artemisia Turanica

Synthesis, in vitro and in vivo evaluation, and computational modeling analysis of thioxothiazolidine derivatives as highly potent and selective α-amylase inhibitors

Diabetes mellitus is not only a critical health concern in this era but also a major cause of damage to other organs such as eyes, nerves, kidneys, hearts and liver. Inhibiting α-amylase enzyme is considered as one of the key strategies for controlling chronic hyperglycemia. Therefore, the current work focuses on design and discovery of a series of thioxothiazolidine derivatives (5a-u and 6a-g) as selective α-amylase inhibitors. The target compounds were synthesized using the Knoevenagel condensation approach and evaluated for their α-amylase and α-glucosidase inhibitory activities. The in vitro assay results demonstrated that the tested thioxothiazolidine derivatives possess significantly high potency than the standard drug acarbose against α-amylase but were inactive against α-glucosidase. Among them, compound 5r exhibited remarkable inhibitory potential depicting an IC50 value of 0.71 ± 0.01 μM, significantly outperforming acarbose against α-amylase. In vivo results further demonstrated that the treatment of diabetic rats with compound 5r led to a significant reduction in blood glucose level, indicating its effectiveness in managing hyperglycemia. Biochemical profiling of the treated rats revealed favorable outcomes, including improved urea, creatinine, ALT, AST, ALP, and HbA1C values. Furthermore, in vivo testing in diabetic rats also demonstrated that treatment with compound 5r caused significant histopathological improvements in the kidney, liver and pancreas compared to acarbose. The Lineweaver-Burk plot analysis indicated that compound 5r inhibits α-amylase through a mixed type of inhibition mechanism. Furthermore, molecular docking and dynamics simulations confirmed the in vitro findings while pharmacokinetic properties suggested compound 5r as a favorable drug candidate for the treatment of diabetic complications.

Artemisia judaica extract is effective against Klebsiella pneumoniae-induced pneumonia in male albino rats

Klebsiella pneumoniae frequently causes pneumonia; it is the eighth leading cause of death and one of the most common infectious causes of mortality. Artemisia judaica is well known for its various therapeutic effects. The goal of this study is to evaluate the efficacy of ciprofloxacin and A. judaica in treating pneumonia in K. pneumoniae infected rats. Transmission electron microscopy (TEM) demonstrated that ciprofloxacin and A. judaica extract had substantial antibacterial properties against K. pneumoniae. Five groups, each with ten rats, were studied: Group 1 (negative control), Group 2 (infected with 1 × 105 CFU/mL of K. pneumoniae solution), Group 3 (infected and treated with 250 mg/kg of A. judaica extract), Group 4 (infected and treated with 500 mg/kg of A. judaica extract), and Group 5 (infected and treated with 500 mg/kg of ciprofloxacin). Animals were sacrificed after 24, 48, and 72 hours of treatment. We found that the A. judaica extract or ciprofloxacin treatment improved the rate of survival of infected rats and reduced bacterial spread in the lungs, liver, and spleen. Groups 3, 4, and 5 had substantial histological improvement in lung pathology, with lower TNF-α levels and elevated IL-4, SOD, and CAT levels relative to the positive controls. We conclude that A. judaica has antioxidant, anti-inflammatory, and antibacterial effects that can help combat pneumonia caused by K. pneumoniae in rats.

Unveiling Pharmacological Promise of Mangifera indica (Haribhanga) Peel Extract: Exploring an Untapped Cultivar Through Biochemical and Computational Approaches

The Haribhanga is one of the most renowned varieties of mango native to the Rangpur region of Bangladesh. The study aimed to explore the in vitro and in vivo pharmacological potentialities of the methanolic extract of Mangifera indica (Haribhanga) (MEMI) peel. The antioxidant, antimicrobial, and antiarthritic activities of MEMI peel were conducted by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, disc diffusion, and protein denaturation assays, respectively. The extract was administered to STZ-induced diabetic mice for 7 days for the observation of blood glucose, body weight, lipid profile, and liver enzyme levels. The gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify phytochemicals in the extract. Subsequently, molecular docking was conducted to predict the binding affinity of the identified compounds. The MEMI peel exhibited notable antioxidant potentiality with an IC50 value of 4.43 ± 0.68 μg/mL and antimicrobial activity against Bacillus cereus with a zone of inhibition of 20.67 ± 1.52 mm. Furthermore, MEMI peel demonstrated substantial antiarthritic activity, with the highest inhibition of denaturation of protein (88%) observed at the highest dose (500 μg/mL). In the in vivo experiments, MEMI peel led to a significant increase in high-density lipoprotein (p < 0.001, p < 0.05), with a significant decrease in blood glucose (p < 0.001), triglycerides, total cholesterol, and low-density lipoprotein (p < 0.0001) in STZ-induced diabetic mice. Comparing the diabetic control mice, the MEMI peel substantially decreased (p < 0.001) the high serum levels of aspartate aminotransferase and alanine aminotransferase. Moreover, the extract significantly improved the body weight (p < 0.001) of diabetic mice after 7 days of treatment. GC-MS analysis identified 28 bioactive compounds, primarily fatty acid esters in the MEMI peel. Di-n-octyl phthalate, terpinen-4-ol, 8,11,14-docosatrienoic acid methyl ester, and phenol, 2-methoxy-4-(2-propenyl)-acetate exhibited the most favorable binding potential in molecular docking studies. The results suggest that MEMI peel possesses antimicrobial, antiarthritic, antidiabetic, antihyperlipidemic, and liver enzyme protective activities as a promising antioxidant.

Evaluation of Vinca Rosea's Protective Effects on Hepatic Function in Streptozotocin-Induced Diabetic Wistar Albino Rats

Background Diabetes mellitus, characterized by chronic hyperglycemia, often leads to severe hepatic dysfunction, including increased liver enzyme levels and histopathological changes in the liver. Streptozotocin (STZ)-induced diabetic rat models provide a valuable method for evaluating potential therapeutic agents that target hepatic complications. Vinca rosea, a medicinal plant with known anti-diabetic properties, has been used traditionally for its hepatoprotective effects, although scientific evidence is limited. Objective This study aimed to evaluate the protective effects of Vinca rosea leaf extract on hepatic function, including biochemical and histopathological changes, in STZ-induced diabetic Wistar albino rats. Methods Thirty male Wistar albino rats were randomly divided into five groups: Normal control (NC), diabetic control (DC), low-dose Vinca rosea (LD, 200 mg/kg), high-dose Vinca rosea (HD, 400 mg/kg), and positive control (PC, metformin 100 mg/kg). Diabetes was induced by a single intraperitoneal injection of STZ (100 mg/kg). Vinca rosea treatment was administered daily for 30 days. Blood samples were collected at 15 and 30 days to assess blood glucose and liver function, including serum bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels. Liver tissue was collected for histopathological examination. Data were analyzed using analysis of variance (ANOVA), with p < 0.05 considered statistically significant. Results The DC group showed significantly elevated blood glucose levels (256 ± 19.8 mg/dL at 15 days and 308.5 ± 13.1 mg/dL at 30 days). Vinca rosea treatment significantly reduced blood glucose in a dose-dependent manner, with the HD group showing the greatest improvement (143 ± 12.7 mg/dL at 15 days and 158.5 ± 10.7 mg/dL at 30 days). Liver function markers, including total and direct bilirubin, AST, and ALT, were significantly elevated in the DC group, indicating hepatic damage. Vinca rosea-treated groups showed significant improvements in all liver function parameters, with the HD group displaying the most substantial reductions in bilirubin, AST, and ALT levels. Histopathological analysis revealed marked hepatocellular damage in the DC group, including necrosis and ballooning degeneration. In contrast, Vinca rosea-treated groups, particularly the HD group, exhibited near-normal liver architecture with minimal damage. Conclusion Vinca rosea demonstrated significant hepatoprotective effects in STZ-induced diabetic rats by reducing blood glucose levels and improving liver function. These results suggest that Vinca rosea could be a promising therapeutic agent for managing diabetes-related hepatic dysfunction.

Dysregulated mTOR networks in experimental sporadic Alzheimer's disease

Background

Beyond the signature amyloid-beta plaques and neurofibrillary tangles, Alzheimer's disease (AD) has been shown to exhibit dysregulated metabolic signaling through insulin and insulin-like growth factor (IGF) networks that crosstalk with the mechanistic target of rapamycin (mTOR). Its broad impact on brain structure and function suggests that mTOR is likely an important therapeutic target for AD.

Objective

This study characterizes temporal lobe (TL) mTOR signaling abnormalities in a rat model of sporadic AD neurodegeneration.

Methods

Long Evans rats were given intracerebroventricular injections of streptozotocin (ic-STZ) or saline (control), and 4 weeks later, they were administered neurobehavioral tests followed by terminal harvesting of the TLs for histopathological study and measurement of AD biomarkers, neuroinflammatory/oxidative stress markers, and total and phosphorylated insulin/IGF-1-Akt-mTOR pathway signaling molecules.

Results

Rats treated with ic-STZ exhibited significantly impaired performance on Rotarod (RR) and Morris Water Maze (MWM) tests, brain atrophy, TL and hippocampal neuronal and white matter degeneration, and elevated TL pTau, AβPP, Aβ, AChE, 4-HNE, and GAPDH and reduced ubiquitin, IL-2, IL-6, and IFN-γ immunoreactivities. In addition, ic-STZ reduced TL pY1135/1136-IGF-1R, Akt, PTEN, pS380-PTEN, pS2448-mTOR, p70S6K, pT412-p70S6K, p/T-pT412-p70S6K, p/T-Rictor, and p/T-Raptor.

Conclusion

Experimental ic-STZ-induced sporadic AD-type neurodegeneration with neurobehavioral dysfunctions associated with inhibition of mTOR signaling networks linked to energy metabolism, plasticity, and white matter integrity.

Longitudinal Analysis of Bone Metabolic Markers and Bone Mechanical Properties in STZ-Induced Diabetic Rats

Background: This longitudinal study examined the early effects of type 1 diabetes on bone mechanical properties and metabolic markers in mature rats, focusing on the natural progression of diabetes-induced changes without external treatments. Methods: Forty-eight 8-month-old male Wistar rats were divided into two groups, with one group receiving a single dose of streptozotocin (STZ, 60 mg/kg). Assessments were performed 2, 4, and 8 weeks post-administration, including serum biochemical analyses, bone marker assessments, and mechanical bone tests. The data were analyzed using two-way ANOVA to evaluate the impact of time and treatment. Results: At 2 weeks, diabetic rats showed increased fasting blood glucose (p < 0.001), decreased insulin levels (p = 0.03), and changes in HOMA markers (p < 0.001), liver enzymes (p < 0.001), inflammatory markers (p < 0.001), and bone metabolism markers (osteocalcin (p < 0.001), OPG (p = 0.006), RANKL (p < 0.001), and OPG/RANKL ratio (p < 0.001)), with initial alterations in bone geometry. By week 4, decreased body weight in the diabetic group (p < 0.001) led to further changes in bone geometry and initial differences in mechanical properties. At 8 weeks, significant declines in body (p < 0.001) and bone (p < 0.001) weights were observed, along with further deterioration in bone geometry and mechanical properties. Conclusions: The study highlights the significant impact of STZ-induced diabetes on bone health as early as two weeks post-STZ administration, with marked temporal changes in biochemical markers and mechanical properties.

Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy

Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.

Antioxidative and anti-diabetic effects of Tapinanthus cordifolius leaf extract on high-fat diet and streptozotocin-induced type 2 diabetic rats

Type 2 diabetes mellitus (T2DM) remains a global health concern despite current treatment options. This study investigated the potential of Tapinanthus cordifolius (TC) leaf extract as a therapeutic agent for T2DM. T2DM was induced in rats using a high-fat diet and streptozotocin. Diabetic rats received daily oral administration of TC extract (200, 400, or 800 mg/kg) and metformin (400 mg/kg) or remained untreated for 21 days. Blood glucose levels, body weight, diabetic symptoms, oxidative stress markers, and gene expression of metabolic regulators were assessed. TC treatment significantly reduced blood glucose levels and restored body weight in diabetic rats, comparable to the effects of metformin. TC also increased antioxidant enzyme activities (SOD, GST, and CAT) and decreased lipid peroxidation in various tissues. Furthermore, TC upregulated gene expression of glucose transporter type 4 (GLUT-4) and adiponectin receptor 2 (ADIPOR-2) while downregulating pro-inflammatory cytokines TNF-α and IL-6. This study provides the first in vivo evidence supporting TC leaf extract's anti-diabetic and antioxidant efficacy. The findings suggest that TC holds promise as a natural therapeutic agent for managing T2DM through multiple mechanisms, including improved glycemic control, enhanced insulin sensitivity, and protection against oxidative stress and tissue damage. In conclusion, this study validates the ethnobotanical use of TC as an anti-diabetic agent. Further research is warranted to isolate the bioactive compounds responsible for these effects.

Empagliflozin alleviates diabetes-induced cognitive impairments by lowering nicotinamide adenine dinucleotide phosphate oxidase-4 expression and potentiating the antioxidant defense system in brain tissue of diabetic rats

BACKGROUND

Diabetes-induced cognitive impairment is a major challenge in patients with uncontrolled diabetes mellitus. It has a complicated pathophysiology, but the role of oxidative stress is central. Therefore, the use of antidiabetic drugs with extra-glycemic effects that reduce oxidative damage may be a promising treatment option.

METHODS

Male Wistar rats were randomly divided into four groups as normal, normal treated, diabetic and diabetic treated (n = 8 per group). Type 1 diabetes was induced by a single intraperitoneal dose of streptozotocin (STZ) (40 mg/kg). Two treatment groups received empagliflozin for 5 weeks (20 mg/kg/po). Cognitive ability was evaluated using open field, Elevated Plus Maze (EPM) and the Morris Water Maze (MWM) tests at study completion. Blood and brain tissue samples were collected - and analysis for malondialdehyde (MDA) and glutathione (GLT) content and catalase (CAT) and superoxide dismutase (SOD) enzyme activity were performed. Additionally, expression of nicotinamide adenine dinucleotide phosphate oxidase-4 (Nox-4) enzyme in brain tissue was analyzed using RT-PCR.

RESULTS

STZ increased blood glucose and induced diabetes with oxidative stress by lowering the antioxidant system potency and increasing Nox-4 expression after 5-weeks in brain tissue accompanied by reduction in cognitive performance. Also, diabetes induced anxiety-like behavior and impaired spatial memory in MWM, EPM and open field tests. However, empagliflozin reversed these changes, improving SOD and CAT activity, GLT content and reducing Nox-4 expression and MDA concentration in brain tissue while improving cognitive ability. It reduced anxiety and depression-related activities. It also improved spatial memory in MWM test.

CONCLUSION

Uncontrolled diabetes negatively impacts mental function and impairs learning and cognitive performance via oxidative stress induction, the Nox-4 enzyme playing a central role. Empagliflozin reverses these effects, improving cognitive ability via promoting the anti-oxidative system and damping Nox-4 free radical generator enzyme expression. Therefore, empagliflozin is a promising treatment, providing both antidiabetic and extra-glycemic benefits for improving brain function in the diabetic milieu.

Investigation on Anti-diabetic Efficacy of a Cucurbitaceae Food Plant from the North-East Region of India: Exploring the Molecular Mechanism through Modulation of Oxidative Stress and Glycosylated Hemoglobin (HbA1c)

BACKGROUND

The medicinal plants of the Cucurbitaceae family, such as Solena heterophylla Lour. fruits, have significant ethnobotanical value and are readily accessible in North East India.

AIMS

We conducted a study on Solena heterophylla Lour. fruits to evaluate their anti-diabetic activity in vivo, standardize their HPTLC, and profile their metabolites using LC-QTOF-MS. We aimed to explore the molecular mechanism behind their effects on oxidative stress and glycosylated hemoglobin (HbA1c).

METHODS

Firstly, the ethyl acetate fraction of Solena heterophylla Lour. fruits was standardized using Cucurbitacin B as a standard marker by conducting HPTLC evaluation. Next, we delved into analyzing metabolite profiling. In addition, the standardized fraction was utilized in an experimental study to investigate the molecular mechanism of action in an in vivo high-fat diet and a low dose of streptozotocin-induced diabetic model.

RESULTS

We have reportedly identified 52 metabolites in the ethyl acetate fraction of Solena heterophylla (EASH). In the in vitro tests, it has been observed that this extract from plants possesses notable inhibitory properties against α-amylase and α-glucosidase. Solena heterophylla fruits with high levels of Cucurbitacin B (2.29% w/w) helped lower FBG levels in animals with EASH treatment. EASH treatment reduced HbA1c levels and normalized liver lipid peroxidation and antioxidant enzyme levels. SGOT, SGPT, and SALP serum enzyme levels also returned to normal.

CONCLUSION

Based on the current evaluation, it was found that EASH exhibited encouraging hypoglycemic effects in diabetic rats induced by a low dose of STZ and high-fat diet, which warrants further investigation.

Mango (Mangifera indica L.) seed kernel extract suppresses hyperglycemia by modulating pancreatic β cell apoptosis and dysfunction and hepatic glucose metabolism in diabetic rats

This study investigated the anti-hyperglycemic action of mango seed kernel extract (MKE) and various mechanisms involved in its actions to improve pancreatic β cells and hepatic carbohydrate metabolism in diabetic rats. An intraperitoneal injection of 60 mg/kg of streptozotocin (STZ) followed by 30 consecutive days of treatment with MKE (250, 500, and 1000 mg/kg body weight) was used to establish a study group of diabetic rats. Using liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) for identification, 26 chemical compounds were found in MKE and the high-performance liquid chromatography (HPLC) analysis of the MKE also revealed the existence of mangiferin, gallic acid, and quercetin. The results confirmed that in each diabetes-affected rat, MKE mitigated the heightened levels of fasting blood glucose, diabetic symptoms, glucose intolerance, total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C). As demonstrated by a remarkable increment in serum and pancreatic insulin, the diabetic pancreatic β cell function was potentiated by treating with MKE. The effect of MKE on diabetic pancreatic apoptosis clearly reduced the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells, which was related to diminished levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and Bax and an increase in Bcl-xL protein expression. Furthermore, diabetes-induced liver damage was clearly ameliorated along with a notable reduction in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and abnormal liver histology. By enhancing anti-oxidant superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, MKE alleviated diabetes-induced pancreatic and liver oxidative damage, as demonstrated by diminished levels of malondialdehyde. In minimizing the expression levels of glucose 6-phosphatase and phosphoenolpyruvate carboxykinase-1 proteins in the diabetic liver, MKE also enhanced glycogen content and hexokinase activity. Collectively, these findings indicate that by suppressing oxidative and inflammatory processes, MKE exerts a potent anti-hyperglycemic activity in diabetic rats which serve to protect pancreatic β cell apoptosis, enhance their function, and improve hepatic glucose metabolism.

Lactoferrin decorated bilosomes for the oral delivery of quercetin in type 2 diabetes: In vitro and in vivo appraisal

Despite its tremendous potential for type 2 diabetes management, quercetin (QRC) suffers poor gastric stability, poor bioavailability, and extensive first pass metabolism. Drug encapsulation into bilosomes (BSL) has proven enhanced properties in-vitro and in-vivo. Herein, this work endeavoured to evaluate efficacy of QRC-encapsulated bilosomes capped with lactoferrin (LF); a milk protein with antidiabetic potential, for type 2 diabetes oral treatment. The optimized formulation (LF-QRC-BSL) was evaluated in-vitro on α-amylase enzyme inhibition and insulin resistant HepG2 cell model and in vivo on streptozocin/high fat diet induced diabetes in rats. LF-QRC-BSL showed a small size (68.1 nm), a narrow PDI (0.18) and a -25.5 mV zeta potential. A high entrapment efficiency (94 %) with sustained release were also observed. LF-QRC-BSL displayed 100 % permeation through excised diabetic rat intestines after 6 h, 70.2 % inhibition of α-amylase enzyme in-vitro and an augmented recovery of glucose uptake in insulin resistant cells. In diabetic rats, LF-QRC-BSL resulted in significant decrease in blood glucose level, improved lipid profile and tissue injury markers with reduced oxidative stress and inflammatory markers. Further, histopathological examination of the kidneys, liver and pancreas revealed an almost restored normal condition comparable to the negative control. Overall, LF-QRC-BSL have proven to be a promising therapy for type 2 diabetes.

The Synergistic Influence of Polyflavonoids from Citrus aurantifolia on Diabetes Treatment and Their Modulation of the PI3K/AKT/FOXO1 Signaling Pathways: Molecular Docking Analyses and In Vivo Investigations

This study was aimed at probing the modulatory influence of polyflavonoids extracted from Citrus aurantifolia, lemon peel extract (LPE-polyflavonoids), on attenuating diabetes mellitus (DM) and its complications. HPLC investigations of the LPE exhibited the incidence of five flavonoids, including diosmin, biochanin A, hesperidin, quercetin, and hesperetin. The in silico impact on ligand-phosphatidylinositol 3-kinase (PI3K) interaction was investigated in terms of polyflavonoid class to explore the non-covalent intakes and binding affinity to the known protein active site. The drug likeness properties and pharmacokinetic parameters of the LPE-polyflavonoids were investigated to assess their bioavailability in relation to Myricetin as a control. Remarkably, the molecular docking studies demonstrated a prominent affinity score of all these agents together with PI3K, implying the potency of the extract to orchestrate PI3K, which is the predominant signal for lessening the level of blood glucose. To verify these findings, in vivo studies were conducted, utilizing diabetic male albino rats treated with LPE-polyflavonoids and other groups treated with hesperidin and diosmin as single flavonoids. Our findings demonstrated that the LPE-polyflavonoids significantly ameliorated the levels of glucose, insulin, glycogen, liver function, carbohydrate metabolizing enzymes, G6Pd, and AGEs compared to the diabetic rats and those exposed to hesperidin and diosmin. Furthermore, the LPE-polyflavonoids regulated the TBARS, GSH, CAT, TNF-α, IL-1β, IL-6, and AFP levels in the pancreatic and hepatic tissues, suggesting their antioxidant and anti-inflammatory properties. In addition, the pancreatic and hepatic GLUT4 and GLUT2 were noticeably increased in addition to the pancreatic p-AKT in the rats administered with the LPE-polyflavonoids compared to the other diabetic rats. Remarkably, the administration of LPE-polyflavonoids upregulated the expression of the pancreatic and hepatic PI3K, AMPK, and FOXO1 genes, emphasizing the efficiency of the LPE in orchestrating all the signaling pathways necessitated to reduce the diabetes mellitus. Notably, the histopathological examinations of the pancreatic and hepatic tissues corroborated the biochemical results. Altogether, our findings accentuated the potential therapeutic role of LPE-polyflavonoids in controlling diabetes mellitus.

Melatonin downregulates the increased hepatic alpha-fetoprotein expression and restores pancreatic beta cells in a streptozotocin-induced diabetic rat model: a clinical, biochemical, immunohistochemical, and descriptive histopathological study

Background

Diabetes mellitus (DM) is a chronic metabolic disorder. Hepatopathy is one of the serious effects of DM Melatonin (MT) is a potent endogenous antioxidant that can control insulin output. However, little information is available about the potential association between melatonin and hepatic alpha-fetoprotein expression in diabetes.

Objective

This study was conducted to assess the influence of MT on diabetes-related hepatic injuries and to determine how β-cells of the pancreas in diabetic rats respond to MT administration.

Materials and methods

Forty rats were assigned to four groups at random (ten animals per group). Group I served as a normal control group. Group II was induced with DM, and a single dose of freshly prepared streptozotocin (45 mg/kg body weight) was intraperitoneally injected. In Group III, rats received 10 mg/kg/day of intraperitoneal melatonin (IP MT) intraperitoneally over a period of 4 weeks. In Group IV (DM + MT), following the induction of diabetes, rats received MT (the same as in Group III). Fasting blood sugar, glycosylated hemoglobin (HbA1c), and serum insulin levels were assessed at the end of the experimental period. Serum liver function tests were performed. The pancreas and liver were examined histopathologically and immunohistochemically for insulin and alpha-fetoprotein (AFP) antibodies, respectively.

Results

MT was found to significantly modulate the raised blood glucose, HbA1c, and insulin levels induced by diabetes, as well as the decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Furthermore, MT attenuated diabetic degenerative changes in the pancreas and the hepatic histological structure, increased the β-cell percentage area, and decreased AFP expression in the liver tissue. It attenuated diabetes-induced hepatic injury by restoring pancreatic β-cells; its antioxidant effect also reduced hepatocyte injury.

Conclusion

Collectively, the present study confirmed the potential benefits of MT in downregulating the increased hepatic alpha-fetoprotein expression and in restoring pancreatic β-cells in a streptozotocin-induced diabetic rat model, suggesting its promising role in the treatment of diabetes.

Lippia javanica (Burm. F.) Herbal Tea: Modulation of Hepatoprotective Effects in Chang Liver Cells via Mitigation of Redox Imbalance and Modulation of Perturbed Metabolic Activities

Introduction: Hepatic oxidative injury is one of the pathological mechanisms that significantly contributes to the development of several liver diseases. In the present study, the hepatoprotective effect of Lippia javanica herbal tea was investigated in Fe2+- mediated hepatic oxidative injury. Methods: Using an in vitro experimental approach, hepatic oxidative injury was induced by co-incubating 7 mM FeSO4 with Chang liver cells that have been pre-incubated with or without different concentrations (15-240 μg/mL) of L. javanica infusion. Gallic acid and ascorbic acid served as the standard antioxidants. Results: The infusion displayed a reducing antioxidant activity in ferric-reducing antioxidant power (FRAP) assay and a potent scavenging activity on 2,2-diphenyl-2- picrylhydrazyl (DPPH) radical. Pretreatment with L. javanica infusion significantly elevated the levels of reduced glutathione and non-protein thiol, and the activities of superoxide dismutase (SOD) and catalase, with concomitant decrease in hepatic malondialdehyde levels, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase and lipase activities. The infusion showed the presence of phytoconstituents such as phenolic compounds, tannins, phenolic glycosides and terpenoids when subjected to liquid chromatography-mass spectrometry analysis. Molecular docking revealed a strong binding affinity of dihydroroseoside and obacunone with both SOD and catalase compared to other phytoconstituents. Conclusion: These results portray a potent antioxidant and hepatoprotective effect of L. javanica, which may support the local usage of the herbal tea as a prospective therapeutic agent for oxidative stress-related liver diseases.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

Stingless Bee (Heterotrigona Itama) Honey and Its Phenolic-Rich Extract Ameliorate Oxidant-Antioxidant Balance via KEAP1-NRF2 Signalling Pathway

Diabetes is associated with an imbalance between oxidants and antioxidants, leading to oxidative stress. This imbalance contributes to the development and progression of diabetic complications. Similarly, renal and liver diseases are characterised by oxidative stress, where an excess of oxidants overwhelms the antioxidant defense mechanisms, causing tissue damage and dysfunction. Restoring the oxidant-antioxidant balance is essential for mitigating oxidative stress-related damage under these conditions. In this current study, the efficacy of stingless bee honey (SBH) and its phenolic-rich extract (PRE) in controlling the oxidant-antioxidant balance in high-fat diet- and streptozotocin/nicotinamide-induced diabetic rats was investigated. The administration of SBH and PRE improved systemic antioxidant defense and oxidative stress-related measures without compromising liver and renal functioning. Analyses of the liver, skeletal muscle and adipose tissues revealed differences in their capacities to scavenge free radicals and halt lipid peroxidation. Transcriptional alterations hypothesised tissue-specific control of KEAP1-NRF2 signalling by upregulation of Nrf2, Ho1 and Sod1 in a tissue-specific manner. In addition, hepatic translational studies demonstrated the stimulation of downstream antioxidant-related protein with upregulated expression of SOD-1 and HOD-1 protein. Overall, the results indicated that PRE and SBH can be exploited to restore the oxidant-antioxidant imbalance generated by diabetes via regulating the KEAP1-NRF2 signalling pathway.

Assessment of Effects of Rosemary Essential Oil on the Kidney Pathology of Diabetic Adult Male Albino Rats

Background Diabetic nephropathy is a severe condition that causes persistent kidney problems and chronic renal failure. Rosemary (Rosmarinus officinalis L) is widely recognized for its antioxidant, antidiabetic, anti-inflammatory, antithrombotic, hepatoprotective, and anticancer activities. The current study evaluated rosemary essential oil (REO) effects on biochemical, histological, and immunohistochemical kidney alterations in streptozotocin (STZ)-induced diabetic rats and compared these effects with those of insulin and both combined. Methods We randomly distributed 36 adult albino rats into 6 groups: normal control (non-diabetic), diabetic (streptozotocin, 55 mg/kg, intraperitoneal), diabetic insulin-treated (Lantus insulin 2 units/day, SC), diabetic REO-treated (REO, 10 ml, nasogastric gavage), and diabetic insulin & REO-treated groups. Biochemical, histological, and immunohistochemical analyses were conducted. Results The diabetic group revealed a substantial increase in blood glucose, urea, creatinine, and uric acid, as well as malondialdehyde (MDA) and catalase (CAT) concentrations in kidney homogenates, high score of tubular injury, and increased glomerulosclerosis, along with marked reduction of total glutathione (GSH) and superoxide dismutase (SOD) when compared to control. Evident improvement was detected in rats treated with REO as it demonstrated antioxidant, anti-inflammatory, anti-apoptotic, pro-proliferative, and mild anti-hyperglycemic effects on diabetic rats, reducing the kidney damage caused by diabetes. Combined insulin and REO restored normal blood glucose, renal excretory function tests, antioxidant markers, and renal cortex histology. Conclusion The data presented in the current study's in vivo animal model suggests that REO supplementation has beneficial nephroprotective effects on the structural and, to a lesser extent, functional levels of diabetic rats. Furthermore, the detected nephroprotective effects of insulin and REO combined are superior to those of either administered alone. However, further studies are needed to evaluate these conclusions in humans further.

Green Coffee Bean Extract Potentially Ameliorates Liver Injury due to HFD/STZ-Induced Diabetes in Rats

The goal of the current study was to examine the therapeutic potential of green coffee bean extract (GCBE) in the treatment of diabetic hepatic damage induced by high-fat diet (HFD) and streptozotocin (STZ) administration. The novelty of this study lies in constructing a newly stabilized in vivo obese diabetic animal model in rats using HFD/STZ for investigating the dose-dependent effect of two commonly used doses of GCBE in hepatoprotection against oxidative stress-induced hepatic damage by measuring many parameters that have not been carried out previously in other studies. GCBE that was used in this study was a hot water extract of green coffee beans with a concentration of 0.1 g ml−1. Male albino rats were given a single dose of STZ (35 mg kg−1), and HFD to induce diabetes mellitus (DM). For 28 days, two separate doses of GCBE 50 mg kg−1 and 100 mg kg−1 were administered orally to diabetic animals. Leptin, liver enzymes, oxidative stress parameters, inflammatory parameters, fasting plasma glucose (FPG), fasting plasma insulin (FPI), and lipid profile levels were examined. Real-time PCR and ELISA were used to quantitatively detect the mRNAs of the genes involved in the insulin signaling pathway, the genes involved in glucose metabolism, and the amounts of proteins. The levels of FPG, lipid profile, liver enzymes, inflammatory markers, and leptin in the HFD/STZ diabetic group revealed a considerable spike, while they considerably decreased after GCBE treatment in a dose-dependent manner. After GCBE treatment, the diabetic group showed a significant rise in the antioxidant markers glutathione, superoxide dismutase, and catalase, as well as a decrease in malondialdehyde and nitric oxide levels. The liver changes caused by HFD/STZ were entirely reversed by GCBE, and most intriguingly, in a dose-dependent manner. We concluded that GCBE can repair the hepatic oxidative damage caused by HFD and STZ by reversing all the previously measured parameters and improving the insulin signaling pathways. GCBE demonstrated strong antifree radical activity and significantly protected cells from oxidative damage caused by HFD/STZ.

Oxidative stress in liver of streptozotocin-induced diabetic mice fed a high-fat diet: A treatment role of Artemisia annua L

Objective. The aim of this study was the investigation of a treatment role of Artemisia annua L. (AA) on liver dysfunction and oxidative stress in high-fat diet/streptozotocin-induced diabetic (HFD/STZ) mice. Methods. Sixty mice were divided into 12 groups including control, untreated diabetic, and treated diabetic ones with metformin (250 mg/kg), and doses of 100, 200, and 400 mg/kg of water (hot and cold) and alcoholic (methanol) extracts of AA. Type 2 diabetes mellitus (T2DM) was induced in mice by high-fat diet for 8 weeks and STZ injection in experimental animals. After treatment with doses of 100, 200 or 400 mg/kg of AA extracts in HFD/STZ diabetic mice for 4 weeks, oxidative stress markers such as malondialdehyde (MDA), glutathione (GSH), and free radicals (ROS) were determined in the liver tissue in all groups. Results. Diabetic mice treated with metformin and AA extracts showed a significant decrease in ROS and MDA concentrations and a notable increase in GSH level in the liver. Effectiveness of higher doses of AA extracts (200 and 400 mg/kg), especially in hot-water and alcoholic ones, were similar to and/or even more effective than metformin. Conclusion. Therapeutic effects of AA on liver dysfunction showed that antioxidant activity of hot-water and alcoholic AA extracts were similar or higher than of metformin.

Protective Effect of Nigella sativa Seed Extract and its Bioactive Compound Thymoquinone on Streptozotocin-induced Diabetic Rats

BACKGROUND

The lack of a substantial breakthrough in the treatment of diabetes, a global issue, has led to an ongoing quest for herbs that contain bioactive elements with hypoglycemic properties.

OBJECTIVE

To investigate the potential protective effect of Nigella sativa seeds ethanol extract and its active ingredient, thymoquinone, on streptozotocin-induced diabetic rats.

METHODS

To induce diabetes, the male Wistar rats were administered an intraperitoneal injection of STZ at a dosage of 90 mg/kg body weight in 0.9 percent normal saline after being fasted for 16 hours and made diabetic Group 1; 7 rats non-diabetic control (saline-treated), Group 2; 7 untreated diabetic rats, Group 3; 7 diabetic rats treated orally with N. sativa extract at a dose of 100 mg/kg body weight, Group 4; 7 diabetic rats treated orally with thymoquinone at a dose of 10 mg/kg body weight and Group 5; 7 diabetic rats treated orally with Metformin at a dose of 5 mg/kg body weight. After the treatment of 28 days, all groups were examined for body weight and biochemical alterations.

RESULTS

The results showed a significant decrease in blood glucose, urea, creatinine, uric acid, total protein, total cholesterol, low-density lipoprotein, and very low-density lipoprotein, while high-density lipoprotein was increased. Hepatic enzymes, alanine transaminase, aspartate aminotransferase, and alkaline phosphate were also normalized and significantly increased body weight.

CONCLUSION

These preliminary findings demonstrate that the ethanol extract of N. sativa seeds and its active ingredient, thymoquinone have a protective effect against streptozotocin-induced diabetic rats. The present study opens new vistas for the use of N. sativa and its bioactive compound, thymoquinone, regarding its clinical application as a new nontoxic antidiabetic agent for managing diabetes mellitus.

Comparative Insights into Four Major Legume Sprouts Efficacies for Diabetes Management and Its Complications: Untargeted versus Targeted NMR Biochemometrics Approach

Interest in the consumption of seed sprouts is gradually increasing as functional foods in the modern Western diet owing to their several nutritional and health benefits. The present study aims to investigate four major legume sprouts derived from faba bean (Vicia faba L.), lentil (Lens esculenta L.), chickpea (Cicer arietinum L.), and fenugreek (Trigonella foenum-greacum L.) for their antidiabetic activity and mitigation of associated complications, i.e., oxidative stress, liver dysfunction, and lipid metabolism, compared with glibenclamide. Biochemical results presented herein further showed that the four sprouts exhibited significant hypoglycemic effects (p < 0.05), with improvement in decreasing of blood glucose levels at different degrees and with faba bean sprout most active at 348% improvement, compared to 364.3% for glibenclamide. Further biochemometric analysis based on a comparison between targeted versus untargeted partial least square (PLS) and regression analyses revealed that faba bean sprouts’ richness in flavonoids was a determinant key factor for such efficacy. In addition, correlation with previously investigated NMR fingerprinting aided in pinpointing other active agents, such as betaine and L-DOPA. Furthermore, the effect on serum liver enzymes, including alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase; oxidative stress markers; and lipid profiles showed significant improvement, especially in the case of faba bean sprout. The study revealed the potential health benefits of legume sprouts in the treatment of diabetes and its associated complications, as well as the potential role of biochemometrics in active agents’ identification in such a complex matrix to be considered for other functional foods investigation.

Investigation of the Chemical Composition, Antihyperglycemic and Antilipidemic Effects of Bassia eriophora and Its Derived Constituent, Umbelliferone on High-Fat Diet and Streptozotocin-Induced Diabetic Rats

This study was designed to investigate the chemical profile, antihyperglycemic and antilipidemic effect of total methanolic extract (TME) of Bassia eriophora and isolated pure compound umbelliferone (UFN) in high-fat diet (HFD)- and streptozotocin (STZ)- induced diabetic rats. TME was subjected to various techniques of chromatography to yield UFN. Diabetes was induced after eight weeks of HFD by administration of STZ (40 mg/kg) intraperitoneally, and experimental subjects were divided into five groups. The diabetic control showed an increase in levels of blood glucose throughout the experiment. Treatments were initiated in the other four groups with glibenclamide (GLB) (6 mg/kg), TME (200 mg/kg and 400 mg/kg) and isolated UFN (50 mg/kg) orally. The effect on blood glucose, lipid profile and histology of the pancreatic and adipose tissues was assessed. Both 200 and 400 mg/kg of TME produced a comparably significant decrease in blood glucose levels and an increase in insulin levels with GLB. UFN began to show a better blood sugar-lowering effect after 14 days of treatment, comparatively. However, both 400 mg/kg TME and UFN significantly returned blood glucose levels in diabetic rats compared to normal rats. Analysis of the lipid profile showed that while HFD + STZ increased all lipid profile parameters, TME administration produced a significant decrease in their levels. Histopathological examinations showed that treatment with TME and UFN revealed an improved cellular architecture, with the healthy islets of Langerhans and compact glandular cells for pancreatic cells distinct from damaged cells in non-treated groups. Conversely, the adipose tissue displayed apparently normal polygonal fat cells. Therefore, these results suggest that TME has the potential to ameliorate hyperglycemia conditions and control lipid profiles in HFD + STZ-induced diabetic rats.

Dehydrated Human Amnion/Chorion Membrane Allografts as an Adjunct Wound Healing Therapy in Diabetic Rats

Chronic, non-healing wounds pose a serious public health issue and the need for new treatment methods is paramount. Dehydrated human amnion/chorion membrane has potential wound healing properties, due to the enrichment of growth factors and anti-inflammatory properties. However, its auxiliary advantage on diabetic wounds with demonstrated safety and efficacy in animal models has not been extensively documented. This study aimed at evincing the wound-healing property of dehydrated human amnion chorion membrane in diabetic and non-diabetic rats. An excisional wound model was developed in 36 male Sprague-Dawley rats that were randomly classified into six groups for two experiments. The non-diabetic rat group included non-diabetic control (G1), dHACM treatment (G2), and dHACM dressing + saline-treatment (G3); (n = 6). Similarly, the diabetic group included diabetic control (G4), dHACM treatment (G5), and dHACM dressing + saline-treatment (G6); (n = 6). The results of wound contractility rate, re-epithelialization, grading of granulation tissue, and collagen deposition from histopathological observation demonstrated that in comparison with the other groups (G1, G2, G4, and G5), the animal groups treated with dHACM dressing + saline-treatment (G3 and G6) had superior regenerative effects in excisional wound model. Also, in the animals of G5 and G6 of the diabetic group, there was no statistically significant difference (P > 0.05) in the levels of glucose, urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphate (ALP), when compared to G4 animals during the experiment. It is evident from this study that dHACM could be applied as a potential wound healing biomaterial, especially in diabetic conditions.

Hamid A, Ugusman A. Effects of Piper sarmentosum Roxb. on hypertension and diabetes mellitus: A systematic review and meta-analysis

Hypertension and diabetes mellitus are among the most prevalent diseases affecting people from all walks of life. Medicinal herbs have garnered interest as potential agents for the prevention and treatment of diabetes mellitus and hypertension due to their multiple beneficial effects. Piper sarmentosum Roxb. (PS) is an edible medicinal plant that has been traditionally used in Asia for treating hypertension and diabetes mellitus. This review is aimed to provide comprehensive information from the literature on the effects of PS on hypertension and diabetes mellitus. A computerized database search was performed on Scopus, PubMed and Web of Science databases with the following set of keywords: Piper sarmentosum AND diabetes mellitus OR diabetic OR diabetes OR hyperglyc*emia OR blood glucose OR HbA1c OR glycated h*emoglobin OR h*emoglobin A1c OR hyperten* OR blood pressure. A total of 47 articles were screened and 14 articles published between the years 1998 until 2021 were included for data extraction, comprising of six articles on antihypertensive and eight articles on antidiabetic effects of PS. These studies consist of two in vitro studies and eleven in vivo animal studies. Meta-analysis of three studies on hypertension showed that PS versus no treatment significantly lowered the systolic blood pressure with mean difference (MD) -39.84 mmHg (95% confidence interval (CI) -45.05, -34.62; p < 0.01), diastolic blood pressure with MD -26.68 mmHg (95% CI -31.48, -21.88; p < 0.01), and mean arterial pressure with MD -30.56 mmHg (95% CI -34.49, -26.63; p < 0.01). Most of the studies revealed positive effects of PS against hypertension and diabetes mellitus, suggesting the potential of PS as a natural source of antidiabetic and antihypertensive agents.

Hepatoprotective potential of flavonoid-rich extracts from Gongronema latifolium benth leaf in type 2 diabetic rats via fetuin-A and tumor necrosis factor-alpha

BACKGROUND

This study assessed the hepatoprotective potential of flavonoid-rich extracts from Gongronema latifolium Benth on diabetes-induced type 2 rats via Fetuin-A and tumor necrosis factor-alpha (TnF-α).

METHODS

In a standard procedure, the flavonoid-rich extract was prepared. For experimental rats, streptozotocin was injected intraperitoneally (45 mg/kg body weight) to induce diabetes mellitus. Following this, rats were given 5% of glucose water for 24 h. Hence, the animals were randomly divided into five groups of ten rats each, consisting of non-diabetic rats, diabetic controls, diabetic rats treated with low and high doses of flavonoid rich-extracts from Gongronema latifolium leaf (FREGL) (13 and 26 mg/kg, respectively), and diabetic rats treated with 200 mg/kg of metformin glibenclamide orally for 3 weeks. Afterwards, the animals were sacrificed, blood and liver were harvested to evaluate different biochemical parameters, hepatic gene expressions and histological examinations.

RESULTS

The results revealed that FREGL (especially at the low dose) significantly (p < 0.05) reduced alanine transaminase (ALT), aspartate aminotransferase (AST) and alkaline phosphate (ALP) activities, lipid peroxidation level, as well as relative gene expressions of fetuin-A and TNF-α in diabetic rats. Furthermore, diabetic rats given various doses of FREGL showed an increase in antioxidant enzymes and hexokinase activity, as well as glucose transporters (GLUT 2 and GLUT 4), and glycogen levels. In addition, histoarchitecture of the liver of diabetic rats administered FREGL (especially at the low dose) was also ameliorated.

CONCLUSION

Hence, FREGL (particularly at a low dose) may play a substantial role in mitigating the hepatopathy complication associated with diabetes mellitus.

Dapagliflozin, Liraglutide, and Their Combination Attenuate Diabetes Mellitus-Associated Hepato-Renal Injury—Insight into Oxidative Injury/Inflammation/Apoptosis Modulation

In this study, we aim to explore the beneficial therapeutic impacts of dapagliflozin (Dapa), a highly potent, reversible, and selective sodium–glucose cotransporter-2 inhibitor, and liraglutide (Lira), a glucagon-like peptide-1 (GLP-1) receptor agonist, as hypoglycaemic agents for the management of diabetes mellitus (DM), as well as their combination against DM-induced complications, including hepato-renal injury. Indeed, the progression of DM was found to be associated with significant hepatic and renal injury, as confirmed by the elevated biochemical indices of hepatic and renal functions, as well as histopathological examination. Dapa, Lira, and their combination effectively attenuated DM-induced hepatic and renal injury, as confirmed by the recovery of hepatic and renal functional biomarkers. The administration of both drugs significantly reduced the tissue contents of MDA and restored the contents of GSH and catalase activity. Moreover, NF-κB and TNF-α expression at the protein and gene levels was significantly reduced in the liver and the kidney. This was in parallel with the significant reduction in the caspase-3 content in the liver and the kidney, as well as suppressed cleaved caspase-3 expression in the hepatic and renal specimens, as confirmed by immune–histochemical analysis. Notably, the combined Dapa/Lira treatment demonstrated an additive superior hepato-renal protective impact compared with the use of either drug alone. Thus, it appears that Dapa and Lira, through the coordinated modulation of oxidative, inflammatory, and apoptotic signalling, confer a significant hepato-renal protective impact against DM-induced complications and tissue injury.

Alterations of Liver Functions and Morphology in a Rat Model of Prediabetes After a Short-term Treatment of a High-fat High-glucose and Low-dose Streptozotocin

BACKGROUND: The administration of high-fat and high-glucose in diet followed by a low-dose streptozotocin injection in rats could mimic hyperglycemia, prediabetic, or diabetic conditions in humans. However, whether the rat model may lead to early liver impairment was still unclear. AIM: This study was aimed to investigate the possible changes in liver functions and morphology in the rat model of prediabetes after a short-term administration of a high-fat and high-glucose diet followed by low-dose streptozotocin injection. METHODS: Eighteen male Wistar rats were divided into nine rats in the control group and nine in the prediabetic group. To induce prediabetic rats, high-fat high-glucose in daily diets for 3 weeks continued with once to twice low-dose streptozotocin was given. Rats in control groups were fed with a standard diet for 2 months. Afterward, we analyzed glucose control parameters, liver functions, and liver histology of the rats. RESULTS: High-fat, high-glucose diet combined with a low dose of streptozotocin successfully caused prediabetics in the rats. There was a significant increase in several liver enzymes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). However, no significant changes were found in the serum lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels. The histological changes in the liver confirmed the increase in liver enzymes. CONCLUSION: Short-term administration of high-fat high-glucose in combination with low-dose streptozotocin triggers alterations in liver functions marker and liver morphology.

Bridelia ferruginea Benth. (Euphorbiaceae) mitigates oxidative imbalance and lipotoxicity, with concomitant modulation of insulin signaling pathways via GLUT4 upregulation in hepatic tissues of diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bridelia ferruginea Benth. (Euphorbiaceae) is among the medicinal plants commonly used for the management of type 2 diabetes (T2D) and its complications.

AIM OF THE STUDY

The hepato-therapeutic effect of the butanol fraction of Bridelia ferruginea leaves was investigated in diabetic rats.

METHODS

The butanol fraction of B. ferruginea was given to type 2 diabetic rats at both low and high doses (150 and 300 mg/kg bodyweight, respectively), while metformin and glibenclamide served as the standard anti-diabetic drugs. A normal toxicological group was administered a high dose of the fraction. At the end of the experimental period, the rats were sacrificed, and their livers and psoas muscle collected. The liver was assayed for oxidative stress markers, liver glycogen content, lipid metabolite profile (using GC-MS) and their metabolic pathways were analyzed using the MetaboAnalyst 5.0 online server. The expression of GLUT4 was also assayed in the liver and muscle as well as the identification of signaling pathways associated with GLUT4 expression using the Enrichr online server. In silico molecular docking was used to investigate the molecular interactions of some postulated compound found in B. ferruginea with GLUT4. The ability of the fraction to stimulate muscle glucose uptake was determined in isolated rat psoas muscle ex vivo.

RESULTS

Treatment with the high dose of fraction caused an inhibition of lipid peroxidation as well as the elevation of catalase, SOD, glutathione reductase and glutathione peroxidase activities in the rat liver. There was an increased expression of GLUT4 in livers and muscles of diabetic rats following treatment with B. ferruginea. Treatment with the fraction also caused inactivation of diabetes-activated pathways and changes in the distribution of the hepatic lipid metabolites. Molecular docking analysis revealed strong molecular interactions of pyrogallol and sitosterol with GLUT4.

CONCLUSIONS

These data illustrate the hepato-protective effect of B. ferruginea in diabetic rats which compare favorably with the tested anti-diabetic drugs (metformin and glibenclamide).

Effects of black cumin seed oil on oxidative stress and expression of membrane-cytoskeleton linker proteins, radixin, and moesin in streptozotocin-induced diabetic rat liver

Background and Aim

This study examined the effects of black cumin seed oil treatment on oxidative stress and the expression of radixin and moesin in the liver of experimental diabetic rats.

Materials and Methods

Eighteen rats were divided into 3 equal groups (control, diabetes, treatment). The control group was not exposed to any experimental treatment. Streptozotocin was administered to the rats in the diabetes and treatment groups. A 2.5 mL/kg dose of black cumin seed oil was administered daily for 56 days to the treatment group. At the conclusion of the experiment, the blood level of malondialdehyde (MDA) and glutathione (GSH) was measured. The expression level and the cellular distribution of radixin and moesin in the liver were analyzed.

Results

The plasma MDA (3.05±0.45 nmol/mL) and GSH (78.49±20.45 μmol/L) levels in the diabetes group were significantly different (p<0.01) from the levels observed in the control group (MDA: 1.09±0.31 nmol/mL, GSH: 277.29±17.02 μmol/L) and the treatment group (MDA: 1.40±0.53 nmol/mL, GSH: 132.22±11.81 μmol/L). Immunohistochemistry and western blotting analyses indicated that while the level of radixin was not significantly between the groups (p>0.05) and moesin expression was significantly downregulated (p<0.05) in the experimental group, the treatment was ineffective.

Conclusion

The administered dose was sufficient to prevent oxidative stress, but was not sufficient to alleviate the effects of diabetes on moesin expression in hepatic sinusoidal cells.

Multi-Mechanistic Antidiabetic Potential of Astaxanthin: An Update on Preclinical and Clinical Evidence

Diabetes mellitus (DM) is a cluster of physiological dysfunctions typified by persistent hyperglycemia. Diet plays a paramount role in human health, and regular consumption of a fruit- and vegetable-rich diet can delay or prevent DM and its associated complications. The promising effect of fruits and vegetables could be partly attributed to their antioxidant constituents, including carotenoids. Carotenoids are natural antioxidants that occur in many vegetables, fruits, microalgae, and other natural sources. Astaxanthin is a xanthophyll carotenoid predominantly present in microalgae and some red-colored marine organisms. It is currently marketed as a health supplement and is well-known for its antioxidant capacity. Accumulating evidence indicates that astaxanthin exerts its beneficial effects against DM by acting on various molecular targets and signaling pathways in multiple organs/tissues. Astaxanthin can lower blood glucose levels by preserving β-cell function, improving insulin resistance (IR), and increasing insulin secretion. This manuscript summarizes the connection between glucose homeostasis, oxidative stress, and DM. This is followed by a review of recent studies on astaxanthin's pharmacological effects against IR, microvascular (diabetic retinopathy, diabetic nephropathy, and neurological damage), and macrovascular DM complications emphasizing the cellular and molecular mechanisms involved. A few lines of clinical evidence supporting its antidiabetic potential are also highlighted.

The effect of Cinnamomum cassia extract on oxidative stress in the liver and kidney of STZ-induced diabetic rats

OBJECTIVES

Many diabetes-related complications are caused by oxidative stress. In the current study, the protective effect of Cinnamomum cassia against diabetes-induced liver and kidney oxidative stress was evaluated.

METHODS

The male Wistar rats (n=48) were randomly divided into six groups including; control group received 500 µL normal saline orally for 42 days. Diabetes groups received intraperitoneally (i.p.) streptozotocin (STZ) as single-dose (60 mg/kg, i.p.). Cinnamon extract (100, 200, 400 mg/kg) and metformin (300 mg/kg) were orally administered to diabetic rats for 42 days. After the experiment period, the animals were anesthetized and the liver and kidney tissues were quickly removed and restored for oxidative stress evaluation. The levels of malondialdehyde (MDA), total thiol content, glutathione (GSH), nitric oxide (NO) metabolites, as well as, superoxide dismutase (SOD) and catalase (CAT) activities were measured in kidney and liver tissue.

RESULTS

The level of MDA, SOD, and CAT activities increased significantly, while the total thiol content, and NO production were significantly reduced in diabetic animals compared to the control group (from p<0.05 to p<0.001). Treatment with cinnamon extract significantly decreased the MDA level, as well as, SOD and CAT activities in the liver and kidney of diabetic rats (from p<0.05 to p<0.001). In the liver and kidney of cinnamon treated groups, GSH and total thiol contents and NO production were significantly higher than diabetic group (from p<0.05 to p<0.001).

CONCLUSIONS

Cinnamon extract due to its potent antioxidant property could be effective in decrease of diabetes-induced oxidative stress that plays a major role in renal and hepatic complications.

Genistein and Momordica charantia L. prevent oxidative stress and upregulate proglucagon and insulin receptor mRNA in diabetic rats

Type 2 diabetes occurs as a result of insulin resistance and dysfunction in insulin signaling. Controlling hyperglycemia and activation of insulin signaling are important in the management of type 2 diabetes. This study aimed to evaluate the effect of genistein and Momordica charantia L. fruit (MCF) on oxidative stress, markers of inflammation, and their role in proglucagon and insulin receptor messenger RNA (mRNA) expression by real-time PCR in diabetic rats. Thirty-five albino rats were divided into 7 groups (n = 5). Group I (non-diabetic) and group II (diabetic control) were treated with distilled water, and groups III and IV received 250 mg/kg and 500 mg/kg lyophilized MCF, respectively. Groups V and VI received 10 mg/kg and 20 mg/kg genistein, respectively, while group VII received 500 mg/kg metformin. The administration lasted for 28 days. MCF and genistein significantly reduced interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α) levels, which were elevated in the serum of diabetic rats. Treatment with MCF and genistein significantly increased the expression of proglucagon mRNA in the small intestine and insulin receptor mRNA in the liver of diabetic rats. In conclusion, MCF and genistein ameliorate type 2 diabetes complications by preventing the loss of insulin-positive cells, inhibiting IL-1β and TNF-α, and upregulating proglucagon and insulin receptor mRNA expression. Novelty: MCF and genistein have an inhibitory effect on diabetic induced IL-1β and TNF-α production. MCF and genistein upregulate proglucagon and insulin receptor mRNA expression.

The role of Artemisia turanica extract on renal oxidative and biochemical markers in STZ-induced diabetes in rat

OBJECTIVE

The aim of the current study was to investigate the protective effect of Artemisia turanica (AT) against diabetes- induced renal oxidative stress in rats.

MATERIALS AND METHODS

Fifty male Wistar rats were randomly divided into five groups: control, STZ-induced diabetic rats, diabetic rats+ metformin, diabetic rats + AT extract, diabetic rats+ metformin+ AT extract. In the present study, diabetes was induced by a single-dose (55 mg/kg, ip) injection of streptozotocin (STZ). Diabetic rats were daily treated with metformin (300 mg/kg), AT extract (70 mg/kg) and metformin+ AT extract for 4 consecutive weeks. Tissue activities of superoxide dismutase (SOD) and catalase and the levels of malondialdehyde (MDA) and total thiol content were measured in kidney tissue. Serum concentrations of glucose, creatinine, and urea, as well as, lipid profile were also measured.

RESULTS

STZ significantly increased the levels of glucose, triglyceride, urea and MDA compared to the control group. Total thiol content, as well as, catalase and SOD activities showed significant decreases in diabetic group when compared with the control animals. Serum glucose, triglyceride, cholesterol and renal MDA showed a significant decrease and renal total thiol and the activities of antioxidant enzymes showed significant increases in AT+STZ group compared with the diabetic group. In diabetic rats received AT+ metformin, serum LDL and HDL, renal MDA and SOD and catalase activities significantly improved compared with the diabetic rats.

CONCLUSION

These findings suggested that AT extract has therapeutic effects on renal oxidative damage and lipid profile in diabetes, that possibly may be due to its antioxidant and hypolipidemic effects.