Curcumin protects rat liver from streptozotocin-induced diabetic pathophysiology by counteracting reactive oxygen species and inhibiting the activation of p53 and MAPKs mediated stress response pathways

Effect of Hesperidin on Lipid Profile, Inflammation and Apoptosis in Experimental Diabetes

In recent years, therapeutic approaches against diabetes-induced liver damage have attracted great interest. Studies indicate the anticarcinogenic, anti-inflammatory, antioxidant, and lipid-lowering potential of hesperidin (HESP), a flavonoid in citrus fruits. This study examined how HESP prevented streptozotocin (STZ)-induced diabetic liver damage. Four groups of seven rats each were created: Control, HESP (100 mg/kg/day), STZ (45 mg/kg), and STZ + HESP (45 mg/kg and 100 mg/kg/day, respectively). Serum AST, ALT, LDH, LDL, triglyceride, total cholesterol levels, and the TNF-α, IL-1β, and caspase-3 expression levels of liver tissue in the STZ group were higher than the other groups (p < 0.05). However, these values were significantly lower (p < 0.05) in the STZ + HESP group compared to the STZ group. Furthermore, administering HESP together with STZ reduced liver expression levels of caspase-3, TNF-α, and IL-1β, as well as blood levels of AST, ALT, LDH, LDL, triglyceride, and total cholesterol. HESP against diabetes-induced hepatic damage reduced proinflammatory cytokine levels, and returned the lipid profile, and apoptotic indicators to normal levels. These findings suggested that HESP therapy may be an important therapeutic role against diabetes-induced liver damage.

Lactobacillus reuteri TISTR 2736 alleviates type 2 diabetes in rats via the hepatic IRS1/PI3K/AKT signaling pathway by mitigating oxidative stress and inflammatory mediators

PURPOSE

This study investigated the beneficial effects of Lactobacillus reuteri TISTR 2736 on glucose homeostasis, carbohydrate metabolism, and the underlying mechanisms of its actions in type 2 diabetic (T2D) rats.

METHODS

A rat model of T2D was established by a combination of a high-fat diet and streptozotocin. The diabetic rats were treated daily with L. reuteri TISTR 2736 (2 × 108 CFU/day) for 30 days. Biochemical, histopathological, and molecular analyses were carried out to determine insulin signaling, carbohydrate metabolism, oxidative stress, and inflammation.

RESULTS

The results demonstrated that treatment with L. reuteri TISTR 2736 significantly ameliorated fasting blood glucose and glucose intolerance, and improved insulin sensitivity indices in the diabetic rats. The hepatic histopathology was improved with L. reuteri TISTR 2736 treatment, which was correlated with a reduction of hepatic lipid profiles. L. reuteri TISTR 2736 significantly reduced glycogen content, fructose 1,6-bisphosphatase activity, and phosphoenolpyruvate carboxykinase 1 protein expression, and enhanced hexokinase activity in the diabetic liver. The downregulation of IRS1 and phosphorylated IRS1Ser307 and upregulation of PI3K and phosphorylated AKTSer473 proteins in the liver were found in the L. reuteri TISTR 2736-treated diabetic group. Furthermore, it was able to suppress oxidative stress and inflammation in the diabetic rats, as demonstrated by decreased malondialdehyde and protein levels of NF-κB, IL-6 and TNF-α, but increased antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase.

CONCLUSION

By inhibiting oxidative and inflammatory stress, L. reuteri TISTR 2736 alleviated hyperglycemia and improved carbohydrate metabolism through activating IRS1/PI3K/AKT pathway in the T2D rats.

Neuroprotective role of curcumin on the hippocampus against the oxidative stress and inflammation of streptozotocin-induced diabetes in rats

In recent years, it has gained importance to determine the effects of diabetes on central nervous system complications. This study aimed to assess the neuroprotective properties of curcumin against neuronal damage in the rat hippocampus caused by diabetes. In accordance with this purpose, we investigated the effects of curcumin on oxidative/antioxidative parameters and pro-inflammatory cytokines in the hippocampal tissue of diabetic Wistar rats. For this purpose, 32 adults, male and healthy Wistar Albino rats were used. Animals were randomly divided into four separate groups: control (C), curcumin(Cu), diabetes (D) and Diabetes + Curcumin (DCu)-treated groups. 60 mg/kg STZ i.p. A single dose was administered to D and DCu groups. Cu and DCu groups were given 50 mg/kg/day curcumin by gavage. After four weeks of treatment, the animals were decapitated under anesthesia and tissue samples were taken for analyses of the parameters (TNF-α, IL-6, IL-1, IL-10, MDA, SOD, catalase, and GSH activities) in the hippocampal tissue. TNF-α, IL-6, IL-1, and MDA levels were increased significantly (p < 0.05) in rats with diabetes compared to the other three groups. TNF-α, IL-6, IL-1, and MDA levels were lower in DCu group animals compared to the D group. It was determined that IL-10, SOD, Catalase, and GSH levels, which were significantly decreased in the D group, increased in the curcumin-supplemented diabetic group (DCu). The relevant sentence has been changed as follows. In conclusion, our findings from this study prove the protective effect of curcumin against diabetes-induced neuropathy in the hippocampus in rats with STZ-induced diabetes.

Monocarbonyl analogs of curcumin C66 and B2BrBC modulate oxidative stress, JNK activity, and pancreatic gene expression in rats with streptozotocin-induced diabetes

The pathogenesis of type 1 diabetes mellitus (T1DM) involves oxidative stress and inflammation. Curcumin, a natural polyphenolic compound found in turmeric, known to exhibit antioxidative and anti-inflammatory properties, is characterized by poor chemical stability, low bioavailability, and rapid metabolism. Monocarbonyl analogs of curcumin (MACs) with a structural absence of β-diketone and enhanced stability and bioavailability present a potential solution to the challenges associated with the use of curcumin. This study aimed to evaluate the effect of two MACs, C66 and B2BrBC, on oxidative stress markers, antioxidant enzyme activity, expression of diabetes-associated genes, and signaling pathway proteins in the context of T1DM. Streptozotocin (STZ)-induced male Wistar rats or rat pancreatic RIN-m cells were used for in vivo and in vitro experiments, respectively. C66 or B2BrBC were given either before or after STZ treatment. Oxidative stress markers and antioxidant enzyme activities were determined in various tissues. Expression of diabetes-associated genes was assessed using RT-qPCR, and the activity of signaling pathway proteins in the pancreas was determined through Western blot analysis. Treatment with C66 and B2BrBC significantly reduced oxidative stress markers and positively influenced antioxidant enzyme activities. Moreover, both compounds inhibited JNK activity in the pancreas while enhancing the expression of genes crucial for β-cell survival and glucose and redox homeostasis. The findings highlight the multifaceted potential of C66 and B2BrBC in ameliorating oxidative stress, influencing gene expression patterns linked to diabetes, and modulating key signaling pathways in the pancreas. The findings suggest that these compounds can potentially address diabetes-related pathological processes.

Quercetin prevents rats from type 1 diabetic liver damage by inhibiting TGF-ꞵ/apelin gene expression

Background

Hyperglycemia-induced oxidative stress is a significant contributor to diabetic complications, including hepatopathy. The current survey aimed to evaluate the ameliorative effect of quercetin (Q) on liver functional disorders and tissue damage developed by diabetes mellitus in rats.

Methods

Grouping of 35 male Wistar rats was performed as follows: sham; sham + quercetin (sham + Q: quercetin, 50 mg/kg/day in 1 ml 1% DMSO for 6 weeks, by gavage); diabetic control (Diabetes: streptozotocin (STZ), 65 mg/kg, i.p.); diabetic + quercetin 1 (D + Q1: quercetin, 25 mg/kg/day in 1 ml 1% DMSO for 6 weeks, by gavage after STZ injection); and diabetic + quercetin 2 (D + Q2: quercetin, 50 mg/kg/day in 1 ml 1% DMSO for 6 weeks, by gavage after STZ injection). Body weight, food intake, and water intake were measured. Ultimately, the samples of plasma and urine, as well as tissue samples of the liver and pancreas were gathered for later assays.

Results

STZ injection ended in elevated plasma blood glucose levels, decreased plasma insulin levels, liver dysfunction (increased activity levels of AST, ALT, and ALP, increased plasma levels of total bilirubin, cholesterol, LDL, triglyceride, decreased plasma levels of total protein, albumin and HDL), enhanced levels of malondialdehyde, diminished activities of antioxidant enzymes (superoxide dismutase, and catalase), reduced level of glutathione (GSH) increased gene expression levels of apelin and TGF-ꞵ, plus liver histological destruction. All these changes were diminished by quercetin. However, the measure of improvement in the D + Q2 group was higher than that of the D + Q1 group.

Conclusions

Quercetin improved liver function after diabetes mellitus type 1, possibly due to reduced lipid peroxidation, increased antioxidant systems, and inhibiting the apelin/TGF-ꞵ signaling pathway.

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.

Investigation of the Effects of Curcumin on GLP1-R in Liver Tissue of Diabetic Rats

The study was designed to investigate the effect of curcumin, known for its antidiabetic properties, on the immunohistochemical localization and gene expression of glucagon-like peptide-1 receptor (GLP-1R) in the liver tissues of experimental diabetic rats using reverse transcription polymerase chain reaction (RT-PCR). For this, 24 Sprague-Dawley rats were divided into four groups-control, sham, diabetic, and diabetic + curcumin groups. The control group received no treatment, and 50 mg/kg streptozotocin was administered to the rats in the diabetic and diabetic + curcumin groups received 50 mg/kg streptozotocin. Once diabetes had been established, 100 mg/kg of curcumin was administered intraperitoneally to rats in the diabetic + curcumin group for a period of 21 days. Thesham group was administeredintraperitoneal ethanol and isotonic sodium chloride solution. At the ends of the experiment,tissues were subjected to histological and immunohistochemical examination to ascertain the localization of GLP-1R. Additionally, RT-PCR was employed to determine the levels of GLP-1R gene expression.The histological examinations revealed that the tissue samples from the control and sham groups exhibited a normal histological structure. In contrasr, the diabetic group displayed a range of degenerative changes, including enlargement of the sinusoidal wall enlargement and vacuolization of the hepatocytes. Furthermore, these degenerative findings were mitigated in the diabetic + curcumin group. In the immunohistochemical examinations, the majority of hepatocytes surrounding the vena centralis, as well as some endothelial, and some Kupffer cells,exhibited positively for GLP-1R. The diabetic group exhibited reduced immunoreactivity, while the diabetic + curcumin group demonstrated elevated immunoreactivity compared to the diabetes group. With regard to the molecular analysis, the mean expression level was observed to be higher in the diabetes + curcumin group. However, no significant difference in GLP-1R gene expression was identified between the groups. In conclusion, the administration of curcumin was observed to enhance GLP-1R expression in the liver of the rats with diabetes. Given that GLP-1R is a targets for diabetes treatment, curcumin can be used as a viable therapeutic agent for treating diabetes and alleviating its complications.

Effects of garlic (Allium sativum L) and Citrullus colocynthis (L.) Schrad individually and in combination on male reproductive damage due to diabetes: suppression of the AGEs/RAGE/Nox-4 signaling pathway

BACKGROUND

Diabetes Mellitus is associated with disturbances in male reproductive function and fertility. Studies have shown that oxidative stress with the subsequent inflammation and apoptosis cause these complications in diabetes. Garlic (G) (Allium sativum L) and Citrullus colocynthis (L.) Schrad (C) both have antidiabetic and antioxidant properties. Recently, we demonstrated their synergistic effects in alleviating reproductive complications when administered concomitantly. However, as even medicinal plants in long term usage may lead to some unwanted side effects of their own, we examined whether with half the original doses of these two medicinal plants we could achieve the desired results.

METHODS

Thirty-five male Wistar rats were divided into five groups (n = 7/group): Control, Diabetic, Diabetic + G (0.5 ml/100 g BW), Diabetic + C (5 mg/kg BW) and Diabetic + GC (0.5 ml/100 g BW of garlic and 5 mg/kg BW of C. colocynthis) groups. The experimental period was 30 days.

RESULTS

Oxidative stress, advanced glycation end products (AGEs), immunoexpression of caspase-3, and expression of mRNAs for receptor for advanced glycation end products (RAGE), NADPH oxidase-4 (NOX-4) and nuclear factor kappa B increased in testis of diabetic rats. Treatment with garlic and C. colocynthis alone showed some beneficial effects, but in the combination form the effectiveness was more profound.

CONCLUSIONS

We conclude that the combination therapy of diabetic rats with lower doses is still as efficient as higher doses; therefore, the way forward for reducing complications in long term consumption.

Therapeutic Potential of Curcumin, a Bioactive Compound of Turmeric, in Prevention of Streptozotocin-Induced Diabetes through the Modulation of Oxidative Stress and Inflammation

This study evaluates the anti-diabetic potential and underlying mechanisms of curcumin in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats. The rats were randomly divided into four groups: normal control, negative control (diabetic group), diabetic group receiving glibenclamide (positive control group), and curcumin plus STZ (treatment group). The anti-diabetic activities of curcumin were examined at a dose of 50 mg/kg body weight through physiological, biochemical, and histopathological analysis. Compared to the normal control group rats, elevated levels of glucose, creatinine, urea, triglycerides (TG), and total cholesterol (TC) and low levels of insulin were found in the negative control rats. Curcumin treatment showed a significant decrease in these parameters and an increase in insulin level as compared to negative control rats. In negative control rats, a reduced level of antioxidant enzymes and an increased level of lipid peroxidation and inflammatory marker levels were noticed. Oral administration of curcumin significantly ameliorated such changes. From histopathological findings, it was noted that diabetic rats showed changes in the kidney tissue architecture, including the infiltration of inflammatory cells, congestion, and fibrosis, while oral administration of curcumin significantly reduced these changes. Expression of IL-6 and TNF-α protein was high in diabetic rats as compared to the curcumin treatment groups. Hence, based on biochemical and histopathological findings, this study delivers a scientific suggestion that curcumin could be a suitable remedy in the management of 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.

Streptozotocin induces renal proximal tubular injury through p53 signaling activation

Streptozotocin (STZ), an anti-cancer drug that is primarily used to treat neuroendocrine tumors (NETs) in clinical settings, is incorporated into pancreatic β-cells or proximal tubular epithelial cells through the glucose transporter, GLUT2. However, its cytotoxic effects on kidney cells have been underestimated and the underlying mechanisms remain unclear. We herein demonstrated that DNA damage and subsequent p53 signaling were responsible for the development of STZ-induced tubular epithelial injury. We detected tubular epithelial DNA damage in NET patients treated with STZ. Unbiased transcriptomics of STZ-treated tubular epithelial cells in vitro showed the activation of the p53 signaling pathway. STZ induced DNA damage and activated p53 signaling in vivo in a dose-dependent manner, resulting in reduced membrane transporters. The pharmacological inhibition of p53 and sodium-glucose transporter 2 (SGLT2) mitigated STZ-induced epithelial injury. However, the cytotoxic effects of STZ on pancreatic β-cells were preserved in SGLT2 inhibitor-treated mice. The present results demonstrate the proximal tubular-specific cytotoxicity of STZ and the underlying mechanisms in vivo. Since the cytotoxic effects of STZ against β-cells were not impaired by dapagliflozin, pretreatment with an SGLT2 inhibitor has potential as a preventative remedy for kidney injury in NET patients treated with STZ.

Effect of Curcumin Consumption on Inflammation and Oxidative Stress in Patients on Hemodialysis: A Literature Review

Advanced chronic kidney disease (CKD) stages lead to exacerbated inflammation and oxidative stress. Patients with CKD in stage 5 need renal hemodialysis (HD) to remove toxins and waste products. However, this renal replacement therapy is inefficient in controlling inflammation. Regular curcumin consumption has been shown to reduce inflammation and oxidative stress in subjects with chronic pathologies, suggesting that the daily intake of curcumin may alleviate these conditions in HD patients. This review analyzes the available scientific evidence regarding the effect of curcumin intake on oxidative stress and inflammation in HD patients, focusing on the mechanisms and consequences of HD and curcumin consumption. The inclusion of curcumin as a dietary therapeutic supplement in HD patients has shown to control the inflammation status. However, the optimal dose and oral vehicle for curcumin administration are yet to be determined. It is important to consider studies on curcumin bioaccessibility to design effective oral administration vehicles. This information will contribute to the achievement of future nutritional interventions that validate the efficacy of curcumin supplementation as part of diet therapy in HD.

Effects of dietary wild bitter melon (Momordica charantia var. abbreviate Ser.) extract on glucose and lipid metabolism in HFD/STZ-induced type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Plant-based extracts to interfere with the onset of diabetes may be a promising approach towards type 2 diabetes mellitus (T2DM). Bitter gourd (Momordica charantia L.) is popularly consumed as an edible and medicinal resource with hypoglycemic effect in China. Wild bitter gourd (Momordica Charantia var. abbreviata Ser.) is a variant of bitter gourd, but there are relatively few studies on it.

AIM OF THE STUDY

The purpose of the experiment is to first screen out the most effective extraction part of Momordica charantia L. and Momordica Charantia var. abbreviata Ser. through the hypoglycemic activity experiment in vitro, and by using a high-fat and high-sugar diet with STZ-induced diabetic rat model in vivo to explore the possible mechanism of action against diabetes.

MATERIALS AND METHODS

This study first performed α-glucosidase, PTP1B and lipase activities inhibition experiments on the alcohol and water extracts of Momordica charantia L. and Momordica Charantia var. abbreviata Ser. Sprague Dawley rats were either given normal feed or a high sugar and fat diet for four weeks, followed STZ (25 mg/kg, via i. p.) was given. Rats with fasting blood glucose ≥11.1 mmol/l after one week were deemed to be diabetic, treatments were administered for four weeks, and then blood samples were used to evaluate hematological and biochemical indicators, and liver was removed for post-analysis. The expression levels of p-AMPK, AMPK, p-PI3K, PI3K, p-AKT, AKT, p-GSK3β, GSK3β, p-IRS-1, IRS-1, GLUT2 were determined by Western blot. At the same time, the chemical components was identified by liquid-mass spectrometry.

RESULTS

Data showed that the ethanol extract of wild bitter gourd (WBGE) had the best ability to regulate glucose and lipid metabolism in vitro. Therefore, we further investigated the antidiabetic effects of oral consumption of WBGE on high-fat diet (HFD) and streptozotocin (STZ)-induced T2DM in SD rats. WBGE effectively reduced blood glucose and lipid levels, alleviated glucose intolerance and insulin resistant. Moreover, WBGE consumption could also inhibited oxidant responses and inflammatory damage. Mechanism studies have shown that WBGE may act by regulating AMPK/PI3K signaling pathway. On the other hand, the content of total phenol, total flavonoids, total saponins and total polysaccharide were measured by UV, 27 compounds were identified by LC-MS.

CONCLUSIONS

These studies explored the role and mechanism of WBGE in regulating glucose and lipid metabolism, and may support the utilization and further investigation of wild bitter gourd as a dietary intervention strategy to prevent diabetes and related metabolic abnormalities.

Nanocurcumin combined with insulin alleviates diabetic kidney disease through P38/P53 signaling axis

Treatments for diabetic kidney disease (DKD) mainly focus on managing hyperglycemia and hypertension, but emerging evidence suggests that inflammation also plays a role in the pathogenesis of DKD. This 10-week study evaluated the efficacy of daily oral nanoparticulate-curcumin (nCUR) together with long-acting insulin (INS) to treat DKD in a rodent model. Diabetic rats were dosed with unformulated CUR alone, nCUR alone or together with INS, or INS alone. The progression of diabetes was reflected by increases in plasma fructosamine, blood urea nitrogen, creatinine, bilirubin, ALP, and decrease in albumin and globulins. These aberrancies were remedied by nCUR+INS or INS but not by CUR or nCUR. Kidney histopathological results revealed additional abnormalities characteristic of DKD, such as basement membrane thickening, tubular atrophy, and podocyte cytoskeletal impairment. nCUR and nCUR+INS mitigated these lesions, while CUR and INS alone were far less effective, if not ineffective. To elucidate how our treatments modulated inflammatory signaling in the liver and kidney, we identified hyperactivation of P38 (MAPK) and P53 with INS and CUR, whereas nCUR and nCUR+INS deactivated both targets. Similarly, the latter interventions led to significant downregulation of renal NLRP3, IL-1β, NF-ĸB, Casp3, and MAPK8 mRNA, indicating a normalization of inflammasome and apoptotic pathways. Thus, we show therapies that reduce both hyperglycemia and inflammation may offer better management of diabetes and its complications.

Ellagic acid protects against non-alcoholic fatty liver disease in streptozotocin-diabetic rats by activating AMPK

CONTEXT

Ellagic acid (EA) is used in traditional medicine to treated hyperlipidaemia.

OBJECTIVE

This study examined if AMPK mediates the anti-steatotic effect of ellagic acid (EA) in streptozotocin (STZ)-induced type 1 diabetes mellitus in rats.

MATERIALS AND METHODS

Adult male Wistar rats (130 ± 10 g) were divided into 6 groups (n = 8 rats/group) as control, control + EA, control + EA + CC an AMPK inhibitor), T1DM, T1DM + EA, and T1DM + EA + CC. The treatments with EA (50 mg/kg/orally) and CC (200 ng/rat/i.p.) were given the desired groups for 12 weeks, daily.

RESULTS

In T1DM-rats, EA reduced fasting glucose levels (44.8%), increased fasting insulin levels (92.8%), prevented hepatic lipid accumulation, and decreased hepatic and serum levels of total triglycerides (54% & 61%), cholesterol (57% & 48%), and free fatty acids (40% & 37%). It also reduced hepatic levels of ROS (62%), MDA (52%), TNF-α (62%), and IL-6 (57.2%) and the nuclear activity of NF-κB p65 (54%) but increased the nuclear activity of Nrf-2 (4-fold) and levels of GSH (107%) and SOD (87%). Besides, EA reduced downregulated SREBP1 (35%), SREBP2 (34%), ACC-1 (36%), FAS (38%), and HMG-CoAR (49%) but stimulated mRNA levels of PPARα (1.7-fold) and CPT1a (1.8-fold), CPT1b (2.9-fold), and p-AMPK (4-fold). All these events were prevented by the co-administration of CC.

DISCUSSION AND CONCLUSIONS

These findings encourage the use of EA to treat hepatic disorders, and non-alcoholic fatty liver disease (NAFLD). Further in vivo and in vitro studies are needed to validate its potential in clinical medicine.

Modulatory effects of curcumin on Singapore grouper iridovirus infection-associated apoptosis and autophagy in vitro

Singapore grouper iridovirus (SGIV) with high pathogenicity can cause great economic losses to aquaculture industry. Thus, it is of urgency to find effective antiviral strategies to combat SGIV. Curcumin has been demonstrated effective antiviral activity on SGIV infection. However, the molecular mechanism behind this action needs to be further explanations. In view of the fact that apoptosis (type I programmed cell death) and autophagy (type II programmed cell death) were key regulators during SGIV infection, we aimed to investigate the relevance between antiviral activity of curcumin and SGIV-associated programmed and clarify the role of potential signaling pathways. Our results showed that curcumin suppressed SGIV-induced apoptosis. At the same time, the activities of caspase-3/8/9 and activating protein-1 (AP-1), P53, nuclear factor-κB (NF-ΚB) promoters were inhibited. Besides, the activation of extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK) and p38 mitogen activate protein kinase (p38 MAPK) signal pathways were suppressed in curcumin-treated cells. On the other hand, curcumin down-regulated protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway to promote autophagy representing by increased LC3 II and Beclin1 expression. Curcumin also hindered the transition of cells from G1 to S phase, as well as down-regulating the expression of CyclinD1. Our findings revealed the resistance curcumin induced to the effects of DNA virus on cell apoptosis and autophagy and the insights gained from this study may be of assistance to understand the molecular mechanism of curcumin against DNA virus infection.

Amelioration of oxidative stress mediated inflammation and apoptosis in pancreatic islets by Lupeol in STZ-induced hyperglycaemic mice

BACKGROUND

Type 1 Diabetes mellitus initiates by loss of pancreatic activity which affects other major organs leading to multi-organ failure. Lupeol, a novel phytochemical, is emerging as a potent bioactive molecule. However, the effect of lupeol on hyperglycaemia is not clearly understood. This study delivers an elaborate vision towards the detailed molecular pathway of lupeol against STZ induced diabetic difficulties of the pancreas.

METHOD

The current experiments were designed to focus on the ameliorative effect of the triterpene in combating oxidative damage on the pancreas in a preclinical streptozotocin induced mouse model. After diabetic induction, the animals were subjected to administration with 75 mg kg-1 body weight of lupeol, thrice a week for 7 weeks. Histological measurements were done to investigate the anatomy of the pancreas as well as molecular mechanisms were explored.

RESULTS

The compound was found to regulate several hyperglycaemic and oxidative stress related markers. Lupeol treatment also reversed the expression levels of inflammatory cytokines (TNF-α and IL-1β) as well as attenuated the NF-κB mediated inflammatory and extrinsic apoptotic pathway.

DISCUSSION

These findings in preclinical streptozotocin induced in vivo mouse model strongly suggest the discovery of novel properties of lupeol against oxidative stress in pancreatic β cells by regulating the NF-κB and extrinsic apoptotic pathway.

An update on molecular mechanisms of curcumin effect on diabetes

Owing to its prevalent nature, diabetes mellitus has become one of the most serious endocrine illnesses affecting a patient's quality of life due to the manifestation of side effects such as cardiovascular diseases, retinopathy, neuropathy, and nephropathy. Curcumin ((1E, 6E) 21, 7-bis (4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), a major compound of turmeric, has been used in conventional medicine because of its safe nature and cost-effectiveness to meliorate diabetes and its comorbidities. These effects have also been observed in rodent models of diabetes resulting in a reduction of glycemia and blood lipids. Both the preventive and therapeutic activities of this compound are due to its antioxidant and anti-inflammatory characteristics. Furthermore, preclinical outcomes and clinical investigation demonstrate that the use of curcumin neutralizes insulin resistance, obesity, and hyperglycemia. Despite the many benefits of curcumin, its two limiting factors, solubility and bioavailability, remain a challenge for researchers; therefore, several methods such as drug formulation, nano-drug delivery, and the use of curcumin analogs have been developed to deliver curcumin and increase its bioavailability. PRACTICAL APPLICATIONS: The rise of people with type 2 diabetes has become a major concern at the global healthcare level. The best diabetes treatments today are anti-diabetic drug administration, lifestyle-related interventions (such as healthy eating and daily physical activity), arterial pressure detection, and fat control. The polyphenol curcumin, found in turmeric, can promote health by acting on a variety of cellular signaling pathways. This review article discusses curcumin and its role in the treatment of diabetes.

Assessment of the possible ameliorative effect of curcumin nanoformulation on the submandibular salivary gland of alloxan-induced diabetes in a rat model (Light microscopic and ultrastructural study)

Background

Nowadays, attention is directed to herbal treatments in an attempt to lessen the adverse effects of diabetes. Nanoformulation of curcumin (NC) was shown to enhance stability and water solubility compared to native curcumin.

Objective

To examine the effect of different NC concentrations on the histopathological structure of the submandibular salivary gland of diabetic rats.

Methods

28 rats were divided equally into 4 groups. Group I: Control group, Group II (diabetic), III (diabetic + nanocurcumin low dose), and IV (diabetic + nanocurcumin high dose): Rats of groups II, III and IV were injected with a single dose of alloxan (140 mg/kg) to induce diabetes. After 7 days, groups III and IV were treated for 6 weeks with NC (100 mg/kg/day) for group III, and (200 mg/kg/day) for group IV. Submandibular salivary glands were assessed histologically, immunohistochemically using α smooth muscle actin (α SMA) and ultrastructurally.

Results

Diabetic samples showed destruction of parenchymal elements of the gland, with thick fiber bundles encircling the excretory ducts and minimal reaction for α SMA. Amelioration of the gland's architecture was detected in groups III and IV with reduction of collagen deposition and elevation of positive immunoreactivity to α SMA.

Conclusion

NC profoundly repaired the induced diabetic histopathological and ultrastructural alterations of the gland in a dose dependent manner.

Antidiabetic efficacy of Trifolium alexandrinum extracts hesperetin and quercetin in ameliorating carbohydrate metabolism and activating IR and AMPK signaling in the pancreatic tissues of diabetic rats

Diabetes is a metabolic disease that is mainly characterized by hyperglycemia. The present work investigated the efficacy of the flavanones hesperetin (HES) and quercetin (Q) extracted from Trifolium alexandrinum (TA) to treat type 2 diabetic rats. Wistar albino rats were supplemented with a high fat diet (HFD) for 2 weeks and then administered streptozotocin to induce diabetes. Diabetic rats were orally treated with Q, HES, and TA extract at concentrations of 40, 50, and 200 mg/kg BW, respectively, for 4 weeks. Various biochemical, molecular, and histological analysis were performed to evaluate the antidiabetic effects of these treatments. Q, HES, and TA extract treatments all significantly improved diabetic rats' levels of serum glucose, insulin, glucagon, liver function enzymes, hepatic glycogen, α-amylase, lipase enzymes, lipid profiles, oxidative stress indicators, and antioxidant enzymes as compared with control diabetic untreated rats. In addition, supplementation with Q, HES, and TA extract attenuated the activities of glucose-6-phosphate; fructose-1,6-bisphospahate; 6-phosphogluconate dehydrogenase; glucose-6-phosphate dehydrogenase; glucokinase; and hexokinase in pancreatic tissue, and they improved the levels of glucose transporter 2 and glucose transporter 4. Furthermore, these treatments modulated the expressions levels of insulin receptor (IR), phosphoinositide 3-kinase (PI3K), AMP-activated protein kinase (AMPK), caspase-3, and interleukin-1β (IL-1β). Enhancement of the histological alterations in pancreatic tissues provided further evidence of the ability of Q, HES, and TA extract to exert antidiabetic effects. Q, HES, and TA extract remedied insulin resistance by altering the IR/PI3K and AMPK signaling pathways, and they attenuated type 2 diabetes by improving the antioxidant defense system.

Actinidia deliciosa Mitigates Oxidative Stress and Changes in Pancreatic α-, β-, and δ-Cells and Immunohistochemical and Histological Architecture in Diabetic Rats

The present study evaluated the antioxidant capacity and antidiabetic effect of Actinidia deliciosa in diabetic rats. Rats were grouped as follows: control, Actinidia deliciosa aqueous extract (ADAE, 1 g/kg, daily and orally), streptozotocin (STZ, 50 mg/kg BW, single intraperitoneal dose), and STZ plus ADAE, respectively. Twenty-eight components were detected by GC-MS analysis with high phenolic contents and high DPPH scavenging activity. In vivo results revealed that rats treated with STZ showed a highly significant elevation in blood glucose and a decrease in insulin hormone levels. Thiobarbituric acid-reactive substances and hydrogen peroxide levels were elevated, while bodyweight, enzymatic, and nonenzymatic antioxidants were significantly decreased. Furthermore, histopathological and immunohistochemical insulin expression, besides ultrastructure microscopic variations (β-cells, α-cells, and δ-cells), were seen in pancreas sections supporting the obtained biochemical changes. Otherwise, rats supplemented with ADAE alone showed an improved antioxidant status and declined lipid peroxidation. Moreover, diabetic rats augmented with ADAE showed significant modulation in oxidative stress markers and different pancreatic tissue investigations compared to diabetic ones. Conclusively, ADAE has a potent antioxidant and hypoglycemic influence that may be utilized as a health-promoting complementary therapy in diabetes mellitus.

Hepatoprotective Effect of Actinidia deliciosa against Streptozotocin-Induced Oxidative Stress, Apoptosis, and Inflammations in Rats

The present research intended to assess the possible protective and hypoglycemic effect of Actinidia deliciosa fruit aqueous extract (ADAE) in diabetic rats. The scavenging antioxidant capabilities of ADAE were evaluated using GC-MS analysis. In addition, rats were divided into four groups: control, ADAE, streptozotocin-induced DM (STZ), and STZ-treated rats + ADAE in an in vivo investigation. GC-MS analysis of ADAE was shown to include major components with high total phenolic contents and high DPPH scavenging activity. In diabetic rats, significant elevation in blood glucose level, lipid peroxidation, bilirubin, and lactate dehydrogenase activity as well as a change in lipid profile was observed, while insulin, body and liver weights, enzymatic and nonenzymatic antioxidants, liver function biomarkers, and protein content were significantly decreased. Furthermore, changes in the expression of the peroxisome proliferator-activated receptor (PPAR-γ), apoptotic, and inflammation-related genes were found. In addition, histological differences in rat liver tissue architecture were discovered, corroborating the biochemical modifications. However, consuming ADAE alone reduced lipid peroxidation and improved antioxidant status. Furthermore, diabetic rats given ADAE showed significant reductions in oxidative stress indicators and biochemical parameters, as well as improved tissue structure, when compared to the diabetic rats' group. Also, ADAE supplementation protects diabetic rats' hepatic tissue by upregulating PPAR-γ and downregulating apoptotic and inflammatory-related gene expression. In conclusion, A. deliciosa has beneficial protective effects so, it might be used as a complementary therapy in diabetes mellitus.

Effect of oligosaccharides on the antioxidant, lipid and inflammatory profiles of rats with streptozotocin-induced diabetes mellitus

Prebiotics, gut microbiota-fermentable substances, delay the development of type I diabetes. In the present study, we investigated the effect of two prebiotics (galacto-oligosaccharides and xylo-oligosaccharides) on the antioxidant protection, lipid profile, and inflammatory activity of rats with streptozotocin-induced diabetes. The following markers were studied - malondialdehyde, 8-hydroxy-2'-deoxyguanosine, ferric reducing ability of plasma (FRAP), triacylglycerols, total cholesterol (TC), high-density lipoproteins, C-reactive protein (CRP), and interleukin-6. Diabetes was induced in male Wistar experimental rats by streptozotocin injection, while the non-diabetic controls were injected with saline. Afterward the oligosaccharides were administered orally to the experimental animals. The blood collected following the decapitation was analyzed by ELISA. A modified protocol was used only for measuring the FRAP values. The galacto-oligosaccharides and xylo-oligosaccharides lowered the malondialdehyde levels in the diabetic rats (p < 0.05). The galacto-oligosaccharides decreased the serum levels of 8-hydroxy-2'-deoxyguanosine (p = 0.01), while the xylo-oligosaccharides increased the FRAP (p < 0.05) in the experimental animals. None of the oligosaccharides affected triacylglycerol and interleukin-6 concentrations, but the galacto-oligosaccharides decreased the TC and CRP levels in the diabetic animals. Both oligosaccharides exert a beneficial effect on the antioxidant protection of the diabetic rats, but have a minor effect on their lipid and inflammatory profiles.

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.

Ameliorative effect of curcumin and zinc oxide nanoparticles on multiple mechanisms in obese rats with induced type 2 diabetes

The present study was carried out to investigate the therapeutic effect of synthesized naturally compounds, curcumin nanoparticles (CurNPs) and metal oxide, zinc oxide nanoparticles (ZnONPs) on a high-fat diet (HFD)/streptozotocin (STZ)-induced hepatic and pancreatic pathophysiology in type 2 diabetes mellitus (T2DM) via measuring AKT pathway and MAPK pathway. T2DM rats were intraperitoneally injected with a low dose of 35 mg/kg STZ after being fed by HFD for 8 weeks. Then the rats have orally received treatments for 6 weeks. HFD/STZ-induced hepatic inflammation, reflected by increased phosphorylation of p38-MAPK pathway's molecules, was significantly decreased after nanoparticle supplementation. In addition, both nanoparticles significantly alleviated the decreased phosphorylation of AKT pathway. Further, administration of ZnONPs, CurNPs, conventional curcumin, and ZnSO4 (zinc sulfate), as well as metformin, effectively counteracted diabetes-induced oxidative stress and inflammation in the internal hepatic and pancreatic tissues. Based on the results of the current study, ZnONPs and CurNPs could be explored as a therapeutic adjuvant against complications associated with T2DM. Both nanoparticles could effectively delay the progression of several complications by activating AKT pathway and down-regulating MAPK pathway. Our findings may provide an experimental basis for the application of nanoparticles in the treatment of T2DM with low toxicity.

Hypoglycemic and hypolipidemic effects of total glycosides of Cistanche tubulosa in diet/streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanche tubulosa (Schrenk) R. Wight (Orobanchaceae) is a frequently prescribed component in many traditional herbal prescriptions which are used to treat diabetes in China. In recent studies, the antidiabetic activity of Cistanche tubulosa extracts have been confirmed. However, no systematic investigation has been reported on the total glycosides of Cistatnche tubulosa (TGCT).

AIM OF THE STUDY

The present study aimed to investigate the hypoglycemic and hypolipidemic effects of TGCT and the potential mechanisms in diet/streptozotocin (STZ)-induced diabetic rats, and to chemically characterize the main constituents of TGCT.

MATERIALS AND METHODS

The major constituents of TGCT were characterized by HPLC/Q-TOF-MS and the analytical quantification was performed with HPLC-DAD. Type 2 diabetic rats were induced by high-fat high-sucrose diet (HFSD) and a single injection of STZ (30 mg/kg). TGCT (50 mg/kg, 100 mg/kg and 200 mg/kg) or metformin (200 mg/kg) were orally administered for 6 weeks. Body weight and calorie intake were monitored throughout the experiment. Fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), area under curve of glucose (AUC-G), glycosylated hemoglobin (HbA1c), fasting insulin, serum C-peptide, glycogen content and insulin sensitivity index were tested. The levels of phosphorylated protein kinase B and phosphorylated glycogen synthase kinase 3β, the activities of hexokinase and pyruvate kinase were assayed. Meanwhile, the changes in serum lipid profiles, superoxide dismutase, glutathione peroxidase, malondialdehyde and inflammatory factors were measured. Histological of pancreas were also evaluated by haematoxylin-eosin stain.

RESULTS

Our investigation revealed the presence of phenylethanoid glycosides (PhGs): echinacoside (500.19 ± 11.52 mg/g), acteoside (19.13 ± 1.44 mg/g) and isoacteoside (141.82 ± 5.78 mg/g) in TGCT. Pharmacological tests indicated that TGCT significantly reversed STZ-induced weight loss (11.1%, 200 mg/kg); decreased FPG (56.4%, 200 mg/kg) and HbA1c (37.4%, 200 mg/kg); ameliorated the OGTT, AUC-G and insulin sensitivity; increased glycogen content (40.8% in liver and 52.6% in muscle, 200 mg/kg) and the activities of carbohydrate metabolizing enzymes; regulated lipid profile changes and the activities of antioxidant enzymes; diminished serum markers of oxidative stress and inflammation in a dose-dependent manner (p < 0.05).

CONCLUSIONS

This study confirmed that TGCT was an effective nutritional agent for ameliorating hyperglycemia and hyperlipidemia in diet/STZ-induced diabetic rats, which might be largely attributed to the activities of TGCT on inhibitions of oxidative stress and inflammation.

Selective in vitro cytotoxicity effect of Drimia calcarata bulb extracts against p53 mutant HT-29 and p53 wild-type Caco-2 colorectal cancer cells through STAT5B regulation

Colorectal cancer is the fourth leading cause of oncological-related deaths and the third most diagnosed malignancy, worldwide. The emergence of chemoresistance is a fundamental drawback of colorectal cancer therapies and there is an urgent need for novel plant-derived therapeutics. In this regard, other compounds are needed to improve the efficacy of treatment against colorectal cancer. Medicinal plants have been effectively used by traditional doctors for decades to treat various ailments with little to no side effects. Drimia calcarata (D. calcarata) is one of the plants used by Pedi people in South Africa to treat a plethora of ailments. However, the anticancer therapeutic use of D. calcarata is less understood. Thus, this study was aimed at evaluating the potential anticancer activities of D. calcarata extracts against human colorectal cancer cells. The phytochemical analysis and antioxidant activity were analysed using LC-MS, DPPH, and FRAP. The inhibitory effects and IC50 values of D. calcarata extracts were determined using the MTT assay. Induction of cellular apoptosis was assessed using fluorescence microscopy, the Muse® Cell Analyser, and gene expression analysis by Polymerase Chain Reaction (PCR). Water extract (WE) demonstrated high phenolic, tannin, and flavonoid contents than the methanol extract (ME). LC-MS data demonstrated strong differences between the ME and WE. Moreover, WE showed the best antioxidant activity than ME. The MTT data showed that both ME and WE had no significant activity against human embryonic kidney Hek 293 cell line that served as non-cancer control cells. Caco-2 cells demonstrated high sensitivity to the ME and demonstrated resistance toward the WE, while HT-29 cells exhibited sensitivity to both D. calcarata extracts. The expression of apoptosis regulatory genes assessed by PCR revealed an upregulation of p53 by ME, accompanied by downregulation of Bcl-2 and high expression of Bax after treatment with curcumin. The Bax gene was undetected in HT-29 cells. The methanol extract induced mitochondrial-mediated apoptosis in colorectal Caco-2 and HT-29 cells and WE induced the extrinsic apoptotic pathway in HT-29 cells. ME downregulated STAT1, 3, and 5B in HT-29 cells. The D. calcarata bulb extracts, therefore, contain potential anticancer agents that can be further targeted for cancer therapeutics.

The investigation of the efficacy ratio of cress seeds supplementation to moderate hyperglycemia and hepatotoxicity in streptozotocin-induced diabetic rats

OBJECTIVE

Oxidative stress resulting from chronic hyperglycemia induced many complications in diabetes and led to disorders and dysfunctions in different organs. This study aimed to evaluate the hepatoprotective rate of cress seeds (CS) or Lepidium sativum seeds in the diet on lowering hyperglycemia and oxidative stress damaging.

METHODS

Diabetes was induced by a single intraperitoneal injection of 60 mg/kg of streptozotocin (STZ). Forty-eight male rats were randomly divided into six groups : (D-0) and (ND-0) diabetic, and non-diabetic groups were fed with a normal diet, (ND-CS2) and (ND-CS5) non-diabetic groups were fed with diet containing 2 % and 5 % of cress seeds respectively, (D-CS2) and (D-CS5) diabetic groups were fed with diet containing 2 % and 5 % of cress seeds respectively. After 28 days of treatment, biochemical, histological, and oxidative parameters were determined. Hepatic and pancreatic histological sections were developed.

RESULTS

STZ-injection caused hyperglycemia accompanied by a disturbance in biochemical parameters and intensified oxidative stress status compared to the (ND-0) group. Hepatic and pancreatic histological sections of diabetic rats showed a disrupted architecture. However, the cress seeds-diet revealed a significant decrease of hyperglycemia and a reduction of the intensity of oxidative stress induced by diabetes compared to the (D-0) group, remarked by a decreased level of Malondialdehyde (MDA) and high levels of glutathione (GSH) and the antioxidant enzymes, led to the decrease of the majority of parameters principally hepatic and lipid profile with histological regeneration.

CONCLUSIONS

Cress seeds supplementation confirmed their potential anti-diabetic and antioxidant activities with higher efficacy of 5 % dose than the lower dose of 2 %. Therefore, 5 % of cress seeds administration seems to be the excellent rate recommended in controlling diabetes and its complications.

Ekakitie L, Kappo AP. Effect of Solanum macrocarpon Linn leaf aqueous extract on the brain of an alloxan-induced rat model of diabetes

Objective

This study was designed to evaluate the protective effect of aqueous extract of Solanum macrocarpon Linn leaf in the brain of an alloxan-induced rat model of diabetes.

Methods

The experimental model of diabetes was induced by a single intraperitoneal injection of freshly prepared alloxan. Rats were then divided into six groups: normal control, diabetes control, diabetes group treated with metformin, and three diabetes groups treated with different concentrations of S. macrocarpon. Rats were sacrificed on day 14 of the experiment and different brain biochemical parameters were assessed and compared between groups.

Results

Administration of different doses of S. macrocarpon leaf aqueous extract was associated with significantly reduced levels of fasting blood glucose, lipid peroxidation, neurotransmitters, cholinesterases, cyclooxygenase-2 and nitric oxide compared with diabetes control rats. In addition, antioxidant enzyme activities were significantly increased in diabetes rats administered 12.45, 24.9 and 49.8 mg/kg body weight of S. macrocarpon versus diabetes control rats.

Conclusion

Aqueous extract of S. macrocarpon Linn leaf may be useful in the management of diabetic neuropathy.

Antioxidative Effects of Curcumin on the Hepatotoxicity Induced by Ochratoxin A in Rats

Ochratoxin A (OTA) is a powerful mycotoxin found in various foods and feedstuff, responsible for subchronic and chronic toxicity, such as nephrotoxicity, hepatotoxicity, teratogenicity, and immunotoxicity to both humans and several animal species. The severity of the liver damage caused depends on both dose and duration of exposure. Several studies have suggested that oxidative stress might contribute to increasing the hepatotoxicity of OTA, and several antioxidants, including curcumin (CURC), have been tested to counteract the toxic hepatic action of OTA in various classes of animals. Therefore, the present study was designed to evaluate the protective effect of CURC, a bioactive compound with different therapeutic properties on hepatic injuries caused by OTA in rat animal models. CURC effects were examined in Sprague Dawley rats treated with CURC (100 mg/kg), alone or in combination with OTA (0.5 mg/kg), by gavage daily for 14 days. At the end of the experiment, rats treated with OTA showed alterations in biochemical parameters and oxidative stress in the liver. CURC dosing significantly attenuated oxidative stress and lipid peroxidation versus the OTA group. Furthermore, liver histological tests showed that CURC reduced the multifocal lymphoplasmacellular hepatitis, the periportal fibrosis, and the necrosis observed in the OTA group. This study provides evidence that CURC can preserve OTA-induced oxidative damage in the liver of rats.

Resveratrol, curcumin and gallic acid attenuate glyoxal-induced damage to rat renal cells

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RES, CUR and GA protected renal cells from GO–induced cells death.

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RES, CUR and GA reduced formation of ROS.

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RES, CUR and GA diminished lipid peroxidation products.

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RES, CUR and GA repressed GO-induced mitochondrial membrane potential collapse.

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RES, CUR and GA decreased lysosomal membrane leakage in GO-treated cells.

Glyoxal (GO), a by-product of glucose auto-oxidation, is involved in the glycation of proteins/ lipids and formation of advanced glycation (AGE) and lipoxidation (ALE) end products. AGE/ALE were shown to contribute to diabetic complications development/progression such as nephropathy. Diabetic nephropathy progression has an oxidative nature. Given the antioxidant effects of polyphenols, potential protective effects of resveratrol, curcumin and gallic acid, in rat renal cells treated with GO, were evaluated in the present work. According to our results, incubation of GO with the cells reduced their viability and led to membrane lysis, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential collapse, and lysosomal membrane leakage. These findings were prevented by pre-treatment with resveratrol, curcumin and gallic acid. Mitochondrial and lysosomal toxic interactions appear to worsen oxidative stress/cytotoxicity produced by GO. Resveratrol, curcumin and gallic acid inhibited ROS formation and attenuated GO-induced renal cell death.

Protective effect of pristine C60 fullerene nanoparticle in combination with curcumin against hyperglycemia-induced kidney damage in diabetes caused by streptozotocin

The present study aims to examine the protective effects of C60 fullerene (C60), Curcumin (CUR; Curcuma longa), C60 + CUR combination against oxidative stress, apoptosis, and changes in cellular level in kidney tissue of diabetic rats. Treatment practices were administered separately to groups for 8 weeks following the approval of diabetes induction. It was observed that the treatment groups had increased antioxidant potential, decreased oxidative stress levels, decreased cholesterol, alpha tocopherol, retinol levels along with improved important changes in fatty acid metabolism compared with the diabetic group. C60, CUR, and C60 + CUR were also determined to act in the direction of reducing kidney damage by activating apoptotic pathways. It can be concluded based on these findings that C60, CUR, and especially C60 + CUR combination has beneficial properties in maintaining kidney tissue and function by effectively preventing oxidative stress, apoptotic changes, and changes at the cellular level in kidney tissue under hyperglycemia conditions. PRACTICAL APPLICATIONS: C60 and CUR have various biological activities which can be indicated as antioxidant, anti-inflammatory, anticancer, neuroprotective, and hepatoprotective. It has been reported that C60 and CUR protect the cells against oxidative injury brought about by reactive oxygen species (ROS). Data acquired from the present study puts forth that C60 and C60 + CUR may be promising agents to prevent damage induced by hyperglycemic conditions in kidney tissue.

Antifibrotic effect of curcumin, N-acetyl cysteine and propolis extract against bisphenol A-induced hepatotoxicity in rats: Prophylaxis versus co-treatment

AIMS

Bisphenol A (BPA) has been shown to induce liver fibrosis in rodents. Therefore, this study examined the protective effect of a triple combination of curcumin (Cur), N-acetyl cysteine (NAC) and propolis (Prp) extract against BPA-induced hepatic fibrosis.

METHODS

100 Wistar male rats were equally assigned into 10 groups; one group was designated as control. 10 rats were gavaged with BPA (50 mg/kg/day) for 8 wk and left un-treated (BPA group). The remaining 80 rats were divided into 8 groups, distributed in 2 models. Protective model: rats were daily co-treated with BPA and Cur (100 mg/kg, p.o) or NAC (150 mg/kg, p.o) or Prp (200 mg/kg, p.o) or their combination for 8 wk. Preventive model: rats were daily treated with Cur or NAC or Prp or their combination for 4 wk before BPA administration and then in the same manner as protective model.

KEY FINDINGS

Current treatment interventions significantly alleviated BPA-induced hepatic damage and fibrosis. They also restored pro-oxidant/antioxidant balance, shifted cytokine balance towards the anti-inflammatory side, decreasing interleukin-1β/interleukin-10 ratio. Moreover, these compounds seem to exert anti-apoptotic effects by increasing the immunoexpression of B-cell lymphoma 2 in hepatocytes and decreasing hepatic caspase-3 content. Finally, they ameliorated extracellular matrix turn over through down-regulation of matrix metalloproteinase-9 and up-regulation of tissue inhibitor of matrix metalloproteinase-2 genetic expression.

SIGNIFICANCE

Current treatments guarded against BPA-induced hepatic fibrosis due to their antioxidant, anti-inflammatory and anti-apoptotic properties, decreasing extracellular matrix turnover. Interestingly, the triple therapy provided hepatoprotection superior to monotherapy. Besides, prophylactic and concurrent treatments seem to be more effective than concurrent treatments.

C-peptide corrects hepatocellular dysfunction in a rat model of type 1 diabetes

C-peptide is gaining much interest recently due to its well-documented beneficial effects on multiple organ dysfunction induced by diabetes. Our study was designed to investigate the effect of C-peptide on hepatocellular dysfunction in diabetic rats. Wistar male rats were separated into four groups: control, diabetic, diabetic + insulin, and diabetic + C-peptide. Serum levels of glucose, insulin, and liver biomarkers were assessed. Liver sections were collected for histopathological examination and immuno-histochemical assessment of tumor necrosis factor alpha (TNF-α). Oxidative stress markers and gene expression of inducible nitric oxide synthase (iNOS), transforming growth factor beta 1 (TGF-β1), and glucose-6-phosphatase (G6Pase) were also measured in liver tissues. C-peptide administration prevented hepatic dysfunction induced by diabetes to a similar extent as that of insulin which was confirmed microscopically. We concluded that C-peptide could be used as an alternative therapy to insulin to correct hepatocellular dysfunction associated with type 1 diabetes mellitus (T1DM).

A Co-Delivery System of Curcumin and p53 for Enhancing the Sensitivity of Drug-Resistant Ovarian Cancer Cells to Cisplatin

In order to enhance the sensitivity of drug-resistant ovarian cancer cells to cisplatin (DDP), a co-delivery system was designed for simultaneous delivery of curcumin (CUR) and p53 DNA. Firstly, the bifunctional peptide K14 composed of tumor targeting peptide (tLyP-1) and nuclear localization signal (NLS) was synthesized. A nonviral carrier (PEI-K14) was synthesized by cross-linking low molecular weight polyethyleneimine (PEI) with K14. Then, CUR was coupled to PEI-K14 by matrix metalloproteinase 9 (MMP9)-cleavable peptide to prepare CUR-PEI-K14. A co-delivery system, named CUR-PEI-K14/p53, was obtained by CUR-PEI-K14 and p53 self-assembly. Furthermore, the physicochemical properties and gene transfection efficiency were evaluated. Finally, ovarian cancer cisplatin-resistant (SKOV3-DDP) cells were selected to evaluate the effect of CUR-PEI-K14/p53 on enhancing the sensitivity of drug-resistant cells to DDP. The CUR-PEI-K14/DNA complexes appeared uniformly dispersed and spherical. The particle size was around 20-150 nm and the zeta potential was around 18-37 mV. It had good stability, high transfection efficiency, and low cytotoxicity. CUR-PEI-K14/p53 could significantly increase the sensitivity of SKOV3-DDP cells to DDP, and this effect was better as combined with DDP. The sensitizing effect might be related to the upregulation of p53 messenger RNA (mRNA), the downregulation of P-glycoprotein (P-gp) mRNA, and the upregulation of BCL2-Associated X (bax) mRNA. CUR-PEI-K14/p53 can be used as an effective strategy to enhance the sensitivity of drug-resistant ovarian cancer cells to DDP.

Curcumin Supplementation Alleviates Polymyxin E-Induced Nephrotoxicity

Background

The last-line agent for gram-negative bacteria that have developed resistance towards commonly used antibiotics is polymyxin E (PolyE). The renal toxicity attributed to this agent limits its use, proper dosing, and eventually its clinical efficacy. Although the exact mechanism of PolyE-induced nephrotoxicity is not obvious, some investigations suggest the role of oxidative stress and its associated events in this complication. Curcumin (CUR) is a potent antioxidant molecule. The aim of the current investigation was the evaluation of the potential nephroprotective properties of CUR in PolyE-treated mice.

Materials and Methods

Mice were randomly allocated into five groups (n = 8 per group). PolyE (15 mg/kg/day, i.v, for 7 days) alone or in combination with CUR (10, 100 and 200 mg/kg, i.p) were administered to mice. Renal injury biomarkers, in addition to markers of oxidative stress and kidney histopathological alterations, were evaluated.

Results

Plasma creatinine (Cr) and blood urine nitrogen (BUN) significantly raised in PolyE group. Oxidative stress biomarkers consisting of reactive oxygen species (ROS) and lipid peroxidation (LPO) also increased, and concomitantly GSH and antioxidant capacity of renal cells significantly decreased following the use of PolyE. Interstitial nephritis, tissue necrosis, and glomerular atrophy were all induced by the use of PolyE in the mice kidney. CUR (10, 100, and 200 mg/kg, i.p) treatment alleviated PolyE-induced oxidative stress and histopathological alterations in the kidney tissue significantly.

Conclusion

According to the results of this study, CUR has a protective role against renal toxicity induced by PolyE. Hence, more research is necessary until this compound could be clinically applicable to alleviate PolyE-induced renal injury.

Shorea roxburghii Leaf Extract Ameliorates Hyperglycemia Induced Abnormalities in High Fat/Fructose and Streptozotocin Induced Diabetic Rats

This study investigated the hypoglycemic effect of the methanol extract of Shorea roxburghii leaves (SRL) in high fat diet/high fructose solution (HFDHF) and streptozotocin (STZ) induced type 2 diabetes mellitus (T2DM) in rats as well as evaluating its ameliorative potentials in altered biochemical and hematological parameters in the treated rats. T2DM was induced in Sprague Dawley (SD) rats by feeding with HFDHF for 4 weeks and administering STZ (35 mg/kg, i. p.). Diabetic rats were given SRL extract at doses of 100 and 400 mg/kg for 30 days. The food and water intake were monitored on a daily basis, while the fasting blood glucose (FBG) levels and body weight were measured weekly. Biochemical and hematological parameters as well as histopathological studies of the pancreas were also evaluated. SRL significantly decreased FBG and improved the body weight, food and water intake of treated diabetic rats. Furthermore, biochemical and hematological parameters including liver and kidney function enzymes, lipid profiles, white blood and red blood cells parameters were markedly ameliorated by SRL. Histopathological analyses of the pancreas indicated reconstitution of β-cells architecture in SRL treated rats. The results of this study suggest that SRL has antidiabetic potential and can be considered for the treatment of T2DM.

Matrix metalloproteinase: An upcoming therapeutic approach for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a debilitating condition where excess collagen deposition occurs in the extracellular matrix. At first sight, it is expected that the level of different kinds of matrix metalloproteinases might be downregulated in IPF as it is a matrix degrading collagenase. However, the role of some matrix metalloproteinases (MMPs) is profibrotic where others have anti-fibrotic functions. These profibrotic MMPs effectively promote fibrosis development by stimulating the process of epithelial to mesenchymal transition. These profibrotic groups also induce macrophage polarization and fibrocyte migration. All of these events ultimately disrupt the balance between profibrotic and antifibrotic mediators, resulting aberrant repair process. Therefore, inhibition of these matrix metalloproteinases functions in IPF is a potential therapeutic approach. In addition to the use of synthetic inhibitor, various natural compounds, gene silencing act as potential natural MMP inhibitor to recover IPF.

Curcumin protects sodium nitrite-induced hepatotoxicity in Wistar rats

In this study, the protective effect of curcumin on sodium nitrite (NaNO2) induced hepatotoxicity was assessed in male Wistar rats. Wistar rats were administered orally daily with 20 mg/kg of curcumin for 28 days and NaNO2 was administered as a single dose of 60 mg/kg on day 28. Lipid profile, liver function biomarkers and C-reactive protein were assessed in the serum; lipid peroxidation, non-enzymatic and enzymatic antioxidants were assessed in the liver. Alanine amino transferases (94.67 U/L), aspartate amino transferases (194.33 U/L), alkaline phosphatases, C-reactive proteins (19.56 ng/L) and lipid peroxidation (8.03 × 10-6 μmol/mg protein) were significantly elevated (P < 0.05), while a significant decrease in lipid profiles (total cholesterol, HDL,LDL, and triglycerides): (0.61,0.37, 0.4 and 0.47 mg/dl respectively), reduced glutathione level (4.16 μmol/mg protein), and decreased catalase, superoxide dismutase and glutathione peroxidase activities with severe histological alterations were observed in the livers of rats exposed to NaNO2. Pre-treatment with curcumin significantly (P < 0.05) prevented these alterations by adjusting the lipid profile, liver function markers, and C-reactive proteins and abrogating the elevated markers of oxidative stress as supported by the liver histology. This suggests that dietary consumption of curcumin is beneficial against NaNO2 induced oxidative stress of the liver via its antioxidant potential.

Curcumin ameliorated myocardial infarction by inhibition of cardiotoxicity in the rat model

Cardiovascular diseases are the main cause of death globally. Many attempts have been done to ameliorate the pathological changes after the occurrence of myocardial infarction. Curcumin is touted as a polyphenol phytocompound with appropriate cardioprotective properties. In this study, the therapeutic effect of curcumin was investigated on acute myocardial infarction in the model of rats. Rats were classified into four groups; control, isoproterenol hydrochloride (ISO) (100 mg/kbw), curcumin (50 mg/kbw), and curcumin plus ISO treatment groups. After 9-day administration of curcumin, levels of lactate dehydrogenase (LDH), creatine kinase (CK), and cardiac troponin I (cTnI) were determined. Superoxide dismutase (SOD) and malondialdehyde (MDA) contents were measured to investigate the oxidative status in infarct rats received curcumin. By using H & E staining, tissue inflammation was performed. Masson's trichrome staining was conducted to show cardiac remodeling and collagen deposition. The number of apoptotic cells was determined by using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Data showed the serum decrease of LDH, CK, and cTnI in infarct rats after curcumin intake compared to the rats given (ISO) ( P < 0.05). Curcumin was found to reduce oxidative status by reducing SOD and MDA contents ( P < 0.05). Gross and microscopic examinations revealed that the decrease of infarct area, inflammation response and collagen deposition in rats given ISO plus curcumin ( P < 0.05). We noted the superior effect of curcumin to reduce the number of apoptotic cardiomyocytes after 9 days. Data point the cardioprotective effect of curcumin to diminish the complication of infarction by the reduction of cell necrosis and apoptosis in a rat model of experimental infarction.

Natural products: An upcoming therapeutic approach to cancer

Cancer is one of the leading causes of death across the world. Different environmental and anthropogenic factors initiate mutations in different functional genes of growth factors and their receptors, anti-apoptotic proteins, self-renewal developmental proteins, tumor suppressors, transcription factors, etc. This phenomenon leads to altered protein homeostasis of the cell which in turn induces cancer initiation, development, progression and survival. From ancient times various natural products have been used as traditional medicine against different diseases. Natural products are readily applicable, inexpensive, accessible and acceptable therapeutic approach with minimum cytotoxicity. As most of the target-specific anticancer drugs failed to achieve the expected result so far, new multi-targeted therapies using natural products have become significant. In this review, we have summarized the efficacy of different natural compounds against cancer. They are capable of modulating cancer microenvironment and diverse cell signaling cascades; thus playing a major role in combating cancer. These compounds are found to be effective against several signaling pathways, mainly cell death pathways (apoptosis and autophagy) and embryonic developmental pathways (Notch pathway, Wnt pathway and Hedgehog pathway). This review article is expected to be helpful in understanding the recent progress of natural product research for the development of anticancer drug.

Chronic exposure to 35% carbamide peroxide tooth bleaching agent induces histological and hematological alterations, oxidative stress, and inflammation in mice

Previous studies have demonstrated the side effects of tooth whiteners on the gastric mucosa. However, the impact of dental bleaching products on the liver, kidney, and heart remains obscure. The present study investigated the toxic potential of 35% carbamide peroxide (CPO) containing tooth whitening product (TWP) on the liver, kidney, heart, and stomach of mice, pointing to the role of oxidative stress and inflammation. Mice received 250 or 500 mg/kg body weight CPO-TWP orally for 3 weeks and samples were collected for analyses. Both doses of CPO-TWP induced a significant increase in circulating liver, kidney, and heart function markers. CPO-TWP-administered mice showed several histological alterations and a significant increase in liver, kidney, heart, and stomach lipid peroxidation levels along with diminished glutathione, superoxide dismutase, and catalase. In addition, administration of CPO-TWP provoked anemia, leukocytosis, and a significant increase in circulating levels of pro-inflammatory cytokines. In conclusion, exposure to 35% CPO-TWP induced functional, histological, and hematological alterations, oxidative stress, and inflammation in mice. Therefore, the frequent use of tooth bleaching agents should be monitored very carefully to avoid the application of excess amounts as well as the intake.

Role of nanostructures in improvising oral medicine

The most preferable mode of drugs administration is via the oral route but physiological barriers such as pH, enzymatic degradation etc. limit the absolute use of this route. Herein lies the importance of nanotechnology having a wide range of applications in the field of nano-medicine, particularly in drug delivery systems. The exclusive properties particularly small size and high surface area (which can be modified as required), exhibited by these nanoparticlesrender these structures more suitable for the purpose of drug delivery. Various nanostructures, like liposomes, dendrimers, mesoporous silica nanoparticles, etc. have been designed for the said purpose. These nanostructures have several advantages over traditional administration of medicine. Apart from overcoming the pharmacokinetic and pharmacodynamics limitations of many potential therapeutic molecules, they may also be useful for advanced drug delivery purposes like targeted drug delivery, controlled release, enhanced permeability and retention (EPR) effect. In this review, we attempt to describe an up-to-date knowledge on various strategically devised nanostructures to overcome the problems related to oral drug administration.