New combination therapy of gliclazide and quercetin for protection against STZ-induced diabetic rats

The comparison of the antidiabetic effects of exenatide, empagliflozin, quercetin, and combination of the drugs in type 2 diabetic rats

BACKGROUND

Type 2 diabetes, a metabolic disease that involves extended treatment, is rapidly increasing in humans and animals worldwide.

OBJECTIVES

This study aimed to compare monotherapy and combined therapy of exenatide, empagliflozin, and quercetin in 67 Wistar Albino male rats.

METHODS

The animals were divided into the following seven groups: healthy control, diabetes control, diabetes + sham, diabetes + exenatide (10 μg/kg), diabetes + empagliflozin (50 mg/kg), diabetes + quercetin (50 mg/kg), and diabetes + combination treatment. The treatments were continued for 8 weeks.

RESULTS

At the end of the experiment, glucose and HbA1c levels decreased with all monotherapy treatments and the combination treatments, while insulin levels increased with exenatide and combined treatments. Adiponectin levels increased with empagliflozin, quercetin, and combined treatments, while leptin levels decreased only with combined treatments. All monotherapies caused an increase in total antioxidant levels. Exenatide and quercetin treatments reduced low-density lipoprotein (LDL) levels; therewithal, exenatide and combined treatments increased high-density lipoprotein (HDL) levels. Triglyceride levels decreased in all treatment groups. The homeostatic model assessment for insulin resistance (HOMA-IR) level decreased with the combined treatment; on the contrary, the homeostatic model assessment for β-cell activity (HOMA-β) level increased with empagliflozin, exenatide, and combined treatments.

CONCLUSION

In conclusion, the antidiabetic effects of exenatide were more pronounced than empagliflozin and quercetin, however, the combined treatment had better antidiabetic and antihyperlipidemic effects than monotherapies. Quercetin could be a supportive or food supplement antidiabetic agent. The exenatide treatment can be recommended for monotherapy in type 2 patients, and the combination of empagliflozin, exenatide, and quercetin may be effective in diabetic patients who need combined therapy.

Quercetin Ameliorates Myocardial Injury in Diabetic Rats by Regulating Autophagy and Apoptosis through AMPK/mTOR Signaling Pathway

A high-glucose environment is involved in the progression of diabetes mellitus (DM). This study aims to explore the regulatory effects of quercetin (QUE) on autophagy and apoptosis after myocardial injury in rats with DM. The type 2 DM rat models were constructed using low-dose streptozotocin (STZ) treatment combined with a high-carbohydrate (HC) diet in vivo. Compared with the control group, the body weight was decreased, whereas blood pressure, blood glucose, and the LVW/BW ratio were increased in the diabetic group. The results showed that the myocardial fibers were disordered in the diabetic group. Moreover, we found that the myocardial collagen fibers, PAS-positive cells, and apoptosis were increased, whereas the mitochondrial structure was destroyed and autophagic vacuoles were significantly reduced in the diabetic group compared with the control group. The expression levels of autophagy-related proteins LC3 and Beclin1 were decreased, whereas the expression levels of P62, Caspae-3, and Bax/Bcl-2 were increased in the diabetic group in vitro and in vivo. Moreover, QUE treatment alleviated the cellular oxidative stress reaction under high-glucose environments. The results of immunoprecipitation (IP) showed that the autophagy protein Beclin1 was bound to Bcl-2, and the binding capacity increased in the HG group, whereas it decreased after QUE treatment, suggesting that QUE inhibited the binding capacity between Beclin1 and Bcl-2, thus leading to the preservation of Beclin1-induced autophagy. In addition, the blood pressure, blood glucose, and cardiac function of rats were improved following QUE treatment. In conclusion, QUE suppressed diabetic myocardial injury and ameliorated cardiac function by regulating myocardial autophagy and inhibition of apoptosis in diabetes through the AMPK/mTOR signaling pathway.

A combination of gliclazide and metformin attenuates obesity-induced polycystic ovary syndrome in female Wistar rats

Presently, it is known that the progression of obesity concomitantly leads to polycystic ovary syndrome and infertility. This study aimed to evaluate the potential effects of metformin (M; insulin secretagogues) and gliclazide (G; insulin sensitizer) alone and their combination at different doses to treat obesity-induced PCOS. High high-fat diet was given to all female Wistar rats for nine weeks to induce obesity except for the normal control group which received a normal chow diet. Estradiol valerate (0.8 mg/kg) was also given to all obese rats to induce polycystic ovarian syndrome. After the induction, M (100, 300 mg/kg) and G (5, 10 mg/kg) were given orally either individually or in combination for 28 days. The notable (p < 0.0001) reduction in body weight and blood glucose level was observed in treatment groups in contrast to disease control (DCG). The marked (p < 0.05-0.0001) decrease in hemocylated hemoglobin, serum insulin, cholesterol, triglycerides, and testosterone was observed in treated groups, notably in combination groups (M100+G10 mg/kg) in contrast to DCG. There was a considerable (p < 0.01-0.0001) increase in progesterone E2, estradiol, luteinizing, and follicle-stimulating hormones in treated groups as compared to DCG. Treatment with M and G treated groups also exhibited marked (p < 0.05-0.0001) increases in SOD, CAT, and GSH while decreased in NO and MDA levels in ovary tissue as evidenced by the histological study of the ovary. Treatment with M and G alone and in combination significantly (p < 0.0001) restored the serum IL-6, NrF2, and NF-κB levels as compared to DCG. The results inveterate that the M and G combination (M100+G10, and M300+G10) was useful in treating obesity-induced infertility due to antioxidant properties, hypolipidemic effects, and modulation of inflammatory markers.

Novel Approaches to Control Diabetes

Diabetes is a chronic, long-term, incurable, but controllable condition. Diabetes mellitus (DM) is a group of metabolic disorders characterized by hyperglycemia that results from defects in insulin secretion, insulin action, or both. People who have diabetes often experience a variety of symptoms, including blurry vision, excessive thirst, fatigue, frequent urination, hunger, and weight loss. This review article includes a discussion on diabetes types, symptoms, diagnostic tests, and various therapies for treating, controlling, and managing blood glucose levels, with a focus on its most recent innovation of therapies and medications. Diabetes management will also be reviewed, along with clinical pharmacodynamics, bioavailability, advantages, and complications of combined drugs/medications.

Mechanisms of action of natural products on type 2 diabetes

Over the past several decades, type 2 diabetes mellitus (T2DM) has been considered a global public health concern. Currently, various therapeutic modalities are available for T2DM management, including dietary modifications, moderate exercise, and use of hypoglycemic agents and lipid-lowering medications. Although the curative effect of most drugs on T2DM is significant, they also exert some adverse side effects. Biologically active substances found in natural medicines are important for T2DM treatment. Several recent studies have reported that active ingredients derived from traditional medicines or foods exert a therapeutic effect on T2DM. This review compiled important articles regarding the therapeutic effects of natural products and their active ingredients on islet β cell function, adipose tissue inflammation, and insulin resistance. Additionally, this review provided an in-depth understanding of the multiple regulatory effects on different targets and signaling pathways of natural medicines in the treatment of T2DM as well as a theoretical basis for clinical effective application.

Onopordum acanthium L. extract attenuates pancreatic β-Cells and cardiac inflammation in streptozocin-induced diabetic rats

BACKGROUND AND OBJECTIVE

Methanolic extract from Onopordum acanthium L. leaves (MEOAL) has been discovered to treat diabetic complications. The objective of this study is to evaluate the ameliorative role of MEOAL on pancreatic islet injury and myocardial inflammation in diabetic rats.

METHODS

Forty male Wister albino rats were allocated into five groups of eight rats each. Group A was the negative control group. Single intraperitoneal injection of streptozocin (50mg/kg) were used for the four experimental groups. Group B served as the positive control group. The rats in Groups C, D, and E received glibenclamide (5mg/kg), MEOAL (200, and 400 mg/kg) respectively, for eight weeks. Group C served as the standard drug group. High performance liquid chromatography (HPLC) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays for antioxidant activity were conducted in MEOAL. In silico study, calculation of molecular binding energy (DG), and inhibition constant (pKi) of bioactive constituents in MEOAL were performed.

RESULTS

Administration of MEOAL significantly increases insulin content in β-cells with a marked enhancement of pancreatic islet structure, resulting in a significant reduction of blood glucose level and body weight loss. MEOAL treatment suppressed the increase of inflammatory cell score in myocardial tissue with an elevation of M2 -like macrophage. The phytochemical studies recorded the presence of six polyphenols, including catechin, kaempferol, syringic acid, p-coumaric acid, epicatechin and gallic acid in MEOAL. Moreover, the antioxidant activity of the extract was greater than that of standard ascorbic acid. The docking studies of the ligands Catechin, kaempferol and epicatechin with proteins showed high affinities with various targets related in β-Cells and cardiac inflammation.

CONCLUSIONS

The attenuation of pancreatic β-Cells damage and cardiac inflammation by MEOAL could be attributed to the presence of Catechin, kaempferol and epicatechin which have high affinities with the receptors namely pancreatic alpha-amylase, glucokinase, COX-2, and COX-1.

Dual role of quercetin in enhancing the efficacy of cisplatin in chemotherapy and protection against its side effects: a review

Chemotherapy has opened a new window in cancer therapy. However, the resistance of cancer cells has dramatically reduced the efficacy of chemotherapy. Cisplatin is a chemotherapeutic agent and its potential in cancer therapy has been restricted by resistance of cancer cells. As a consequence, the scientists have attempted to find new strategies in elevating chemotherapy efficacy. Due to great anti-tumour activity, naturally occurring compounds are of interest in polychemotherapy. Quercetin is a flavonoid with high anti-tumour activity against different cancers that can be used with cisplatin to enhance its efficacy and also are seen to sensitise cancer cells into chemotherapy. Furthermore, cisplatin has side effects such as nephrotoxicity and ototoxicity. Administration of quercetin is advantageous in reducing the adverse effects of cisplatin without compromising its anti-tumour activity. In this review, we investigate the dual role of quercetin in enhancing anti-tumour activity of cisplatin and simultaneous reduction in its adverse effects.

Ethnomedical, phytochemical and pharmacological insights on an Indian medicinal plant: The balloon vine (Cardiospermum halicacabum Linn.)

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiospermum halicacabum Linn. (C. halicacabum) is one of the well-known leafy green vegetables in India. It is an herbaceous climber from the Sapindaceae family which is found in almost every Continent and Oceania. In the traditional Indian medicine systems, this plant is used for the treatment of rheumatism, abdominal pain, orchitis, dropsy, lumbago, skin diseases, cough, nervous disorders, and hyperthermia.

AIM OF THE REVIEW

This review presents the current information about ethnomedical uses and progress on geographical distribution, pharmacological activities, phytochemistry, micropropagation, and toxicity of C. halicacabum. Also, critically summarizes the relationship between the reported pharmacological activities and the traditional usages along with the future perspectives for research on this medicinal plant.

MATERIALS AND METHODS

The data on C. halicacabum were collected using multiple internet sources such as Google Scholar, Science Direct, Taylor & Francis, PubMed, Web of Science, Springer Link, Wiley online, and plant databases.

RESULTS

Chemical characterization using LC-MS/MS, HPLC, and NMR exposed the presence of chlorogenic acid, caffeic acid, coumaric acid, luteolin-7-o-glucuronide, apigenin-7-o-glucuronide, and chrysoeriol in different parts of C. halicacabum. Based on the outcomes of this review, the main bioactive compounds found in C. halicacabum include phenols, phenolic acids, flavonoids, flavonoid glycosides, and flavonoid glucuronides. Besides the above-mentioned constituents, palmitic acid, oleic acid, stearic acid, linolenic acid, eicosenoic acid, and arachidic acid are the compounds that constitute the fatty acid profile of C. halicacabum seeds. Specifically, Cardiospermin, a bioactive compound isolated from the root extract of C. halicacabum has been recognized for its anxiolytic activity. Moreover, C. halicacabum showed a broad spectrum of pharmacological activities including anti-inflammatory, anti-arthritic, anti-diabetic, anxiolytic activity, antiulcer, apoptotic activity, antibacterial, antiviral, anti-diarrheal, antioxidant, hepatoprotective, and nephroprotective properties. However, the bioactive compounds responsible for most of the above therapeutic properties have not been elucidated till now.

CONCLUSION

Phytochemicals from C. halicacabum showed noticeable pharmacological effects against plethora of health disorders. Some of the traditional applications were supported by modern scientific studies, however, more pharmacological evaluations should be conducted to validate other traditional uses of C. halicacabum. Despite C. halicacabum's vast pharmacological activity, additional human clinical trials are needed to determine the potent and safe dosages for the treatment of various health abnormalities. Besides, bioassay-guided isolation of active constituents, pharmacokinetic evaluations and identification of their mode of action are recommended for future investigations on C. halicacabum to unveil its therapeutic drug leads. Overall, this review suggests that C. halicacabum could be a new source of functional foods.

Plukenetia conophora seed oil ameliorates streptozotocin-induced hyperglycemia and oxidative stress in rats

PURPOSE

Plukenetia conophora (African walnut) is an edible seed, widely cultivated for its ethnomedicinal and nutritional purposes. Consumption of African walnuts has been linked with blood sugar lowering effect.

OBJECTIVE

The effects of P. conophora seed oil treatment on hyperglycemia and oxidative stress were investigated in plasma, liver and kidney of streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Plukenetia conophora seed oil (PCO) was obtained by extraction of pulverized dried seed in n-hexane. Diabetes was induced by STZ injection (65 mg/kg, i.p). Rats were assigned into non-diabetic control and diabetic control (treated with vehicle), PCO (200 mg/kg) and pioglitazone (10 mg/kg). Fasting blood sugar (FBS) was taken from overnight fasted animals on day 7 and 14 respectively. Plasma, liver and kidney samples were obtained on day 14 for the determination of oxidative stress parameters malondialdehyde (MDA), reduced glutathione (GSH), catalase and superoxide dismutase (SOD).

RESULTS

PCO treatment significantly (p < 0.05) reduced STZ-induced hyperglycaemia by lowering the elevated FBS. PCO significantly reduced MDA level and attenuated STZ-induced depletion of GSH, catalase and SOD in the diabetic rats' plasma, liver and kidneys.

CONCLUSION

These results suggest that consumption of Plukenetia conophora seed might offer protection against diabetes-induced hepatic and renal damage.

The ameliorative effect of bromelain on STZ-induced type 1 diabetes in rats through Oxi-LDL/LPA/LPAR1 pathway

AIMS

Diabetes, a serious worldwide problem, is modulated via inflammation and oxidative stress. Bromelain, a natural compound, recently attracts interest due to its anti-inflammatory effects, while its mode of action remains not properly understood. Thus, investigating the antidiabetic effect of bromelain is promising.

MATERIALS AND METHODS

Rats were randomized into normal group, STZ group (were administrated single intraperitoneal (i.p) injection of 55 mg/kg streptozotocin (STZ)) and STZ + Bro group (were administrated single i.p injection of STZ, 72 h later were i.p administrated 10 mg/kg/day bromelain for 15 days). Wound healing ability was investigated for different groups. Spectrophotometry, ELISA, histopathological and immunohistochemical techniques were applied.

KEY FINDINGS

Bromelain significantly decreased fasting blood glucose, serum triglycerides and cholesterol and hepatic malondialdehyde levels compared with STZ group. Moreover, Bromelain significantly increased serum albumin and total protein levels and percentage of wound healing compared with STZ group. These results were confirmed through the histopathological examination of liver, pancreas, and skin tissues. Investigating the molecular mechanism underlying these effects, STZ injection caused significant increase in hepatic oxidized-LDL (Oxi-LDL) and lysophosphatidic acid (LPA) levels and hepatic lysophosphatidic acid receptor 1 (LPAR1), and beta secretase (BACE1) protein tissue expressions, while bromelain significantly aborted these effects. Thus, STZ caused upregulation of Oxi-LDL/LPA/LPAR1/BACE1 pathway, while bromelain significantly ameliorated these effects.

SIGNIFICANCE

To our best knowledge, this study represents the 1^st study investigating Oxi-LDL/LPA/LPAR1/BACE1 pathway in STZ-induced diabetes in rats, in addition to the promising ameliorative effect of bromelain in STZ-induced diabetes in rats.

Ameliorative Effects of Quercetin and Metformin and Their Combination Against Experimental Endometriosis in Rats

Endometriosis, as the leading cause of infertility, is attributed to oxidative stress, inflammation, and autophagy dysregulation. This study was conducted to evaluate the effect of quercetin and metformin, alone or in combination, on the ectopic and eutopic endometrial tissues in a rat model of endometriosis. We divided 60 female rats into 6 groups, including SH, Endo, Endo + Oil, Endo + Q, Endo + M, and Endo + Q + M. The last five groups underwent a surgery, so that we could induce endometriosis, and after 4 weeks, daily treatment began, lasting for a month. Subsequently, the size and histoarchitecture of the endometrial implants, serum levels of 17β-estradiol, progesterone and tumor necrosis factor (TNF)-α, and markers of oxidative stress and autophagy were assessed utilizing ELISA and gene expression analysis. Our results shed light to the fact that serum TNF-α and 17β-estradiol levels significantly increased in endometriosis rats. Moreover, NADPH: quinone oxidoreductase (NQO1) enzyme activity and gene expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and autophagy markers significantly decreased; meanwhile, mammalian target of rapamycin (mTOR) gene expression increased in the ectopic endometrial tissues, as compared with eutopic ones. Surprisingly, our results demonstrated that the treatment in which we applied the combination of quercetin and metformin significantly reversed these changes and had a pronounced effect on the endometrial implant size and gene expression levels of mTOR and autophagy markers in ectopic endometrium. The findings of the present study suggest that quercetin, metformin, and their combination were of potential therapeutic effects on the rat model of endometriosis.

ASBT(SLC10A2): A promising target for treatment of diseases and drug discovery

Bile acids has gradually become a new focus in various diseases, and ASBT as a transporter responsible for the reabsorption of ileal bile acids, is a key hinge associated to the bile acids-cholesterol balance and bile acids of enterohepatic circulation. The cumulative studies have also shown that ASBT is a promising target for treatment of liver, gallbladder, intestinal and metabolic diseases. This article briefly reviewed the process of bile acids enterohepatic circulation, as well as the regulations of ASBT expression, covering transcription factors, nuclear receptors and gut microbiota. In addition, the relationship between ASBT and various diseases were discussed in this paper. According to the structural classification of ASBT inhibitors, the research status of ASBT inhibitors and potential ASBT inhibitors of traditional Chinese medicine (such resveratrol, jatrorrhizine in Coptis chinensis) were summarized. This review provides a basis for the development of ASBT inhibitors and the treatment strategy of related diseases.

Evaluation of biomarkers in liver following Solanum melongena green calyx administration in diabetic rats

Background

Solanum melongena green calyx (SMGC) has antioxidant properties. Diabetes mellitus (DM) increases oxidative stress and causes cellular damages in liver. This study attempts to show the protective effects of SMGC against morphometric, inflammatory, oxidative, and apoptotic changes in liver following DM induction.

Methods

For DM induction, the streptozotocin (60 mg/kg) was injected intraperitoneally. After the preparation of the SMGC extract, phytochemical content was analyzed. Sixty-four rats were categorized into 8 groups (n = 8); control, diabetic, SMGC, and diabetic + SMGC. SMGC administration was applied orally with doses of 100, 300, 500 mg/kg for 4 weeks. The assays of nitrite oxide, lipid peroxidation (LP), and Ferric Reducing Ability of Plasma (FRAP) were conducted for sample analysis. P53, Bcl2, and Bax genes expression, inflammatory cytokines, enzymes, and morphological features were measured. Apoptotic cell index, body weight, and levels of glucose and insulin were also analyzed. A one-way ANOVA test was used for statistical analysis.

Result

According to the phytochemical analysis, the SMGC is rich in Tannins and Saponins. Antioxidant values, p53 and Bax genes expression, inflammatory cytokines, enzymes, body weight, serum glucose, and morphometrical features were increased significantly (except insulin and FRAP levels and Bcl2 gene expression which were decreased) in diabetic group compared to the control group (P < 0.05). Also, evaluated parameters were reduced significantly (except insulin and FRAP levels and Bcl2 gene expression which were increased) in SMGC and diabetic + SMGC groups in comparison with the diabetic group (P < 0.05).

Conclusion

These findings revealed that the SMGC attenuates blood glucose levels in diabetic animals and also eliminates destructive effects of DM on liver through antioxidant features.

Nanocurcumin improved glucose metabolism in streptozotocin-induced diabetic rats: a comparison study with Gliclazide

In the present study, the biochemical effect of nanocurcumin (nanoCUR) compared with Gliclazide (GLZ) on the diabetic rats was studied. Forty male albino rats (Sprague Dawley) weighted 110 ± 20 g were used. Rats were randomly separated into two groups. Control, received no treatment. Streptozotocin (STZ)-induced diabetic groups take 5 ml/kg of STZ in normal saline daily for 30 days, further divided into diabetic non-treated group, did not receive any treatment: diabetic group treated by nanoCUR, received 15 mg/kg/day of nanoCUR orally for 30 days; diabetic group treated by GLZ, received 2 mg/kg/day of GLZ for 30 days. The mean body weights of all rats were registered and serum samples were collected for determination of fasting blood glucose (FBG), insulin concentration, liver glucokinase (GK), and glycogen synthase (GS) activities. Liver tissues were collected for determination of mRNA expression of insulin (INS), insulin receptor A (IRA), glucokinase (GK), and glucose transporter 2 (GLUT2). The results revealed a significant reduction of body weight in diabetic rats, with no significant differences in nanoCUR and GLZ groups. There was a decline in FBG levels and significant elevation of INS levels, GK, and GS activities in diabetic rats received nanoCUR and GLZ. mRNA expression of INS, IRA, GK, and GLUT2 significantly upregulated in diabetic rats received nanoCUR and GLZ. The amazing observation was a non-significant difference in all measured parameters between nanoCUR and GLZ groups. In conclusion, nanoCUR is able to improve cellular uptake of glucose, the hepatic insulin signaling, and insulin sensitivity in diabetic rats. Its effect was similar to standard hypoglycemic drug (GLZ).

Quercetin Attenuates Pancreatic and Renal D-Galactose-Induced Aging-Related Oxidative Alterations in Rats

Aging is an oxidative stress-associated process that progresses with age. Our aim is to delay or attenuate these oxidative alterations and to keep individuals healthy as they age using natural compounds supplementation. Therefore, we conducted the present study to investigate the protective potentials of quercetin against D-galactose (D-gal)-associated oxidative alterations that were induced experimentally in male Wistar rats. Forty-five rats were randomly allocated into five groups of nine rats each. The groups were a control group that was reared on a basal diet and injected subcutaneously with 120 mg D-gal dissolved in physiological saline solution (0.9% NaCl) per kg body weight daily and quercetin-treated groups that received the same basal diet and subcutaneous daily D-gal injections were supplemented orally with 25, 50, and 100 mg of quercetin per kg body weight for 42 days. Pancreatic and renal samples were subjected to histopathological, immunohistochemical, and relative mRNA expression assessments. Aging (p53, p21, IL-6, and IL-8), apoptotic (Bax, CASP-3, and caspase-3 protein), proliferative (Ki67 protein), antiapoptotic (Bcl2 and Bcl2 protein), inflammatory (NF-κB, IL-1β, and TNF-α), antioxidant (SOD1), and functional markers (GCLC and GCLM genes and insulin, glucagon, and podocin proteins) were determined to evaluate the oxidative alterations induced by D-gal and the protective role of quercetin. D-gal caused oxidative alterations of the pancreas and kidneys observed via upregulations of aging, apoptotic, and inflammatory markers and downregulated the antiapoptotic, proliferative, antioxidant, and functional markers. Quercetin potentially attenuated these aging-related oxidative alterations in a dose-dependent manner. Finally, we can conclude that quercetin supplementation is considered as a promising natural protective compound that could be used to delay the aging process and to maintain human health.