Nigella sativa Relieves the Altered Insulin Receptor Signaling in Streptozotocin-Induced Diabetic Rats Fed with a High-Fat Diet

Efficacy of red algae and artichoke extracts in disrupting antioxidant/PI3K/RBP-4 pathway in high-fat diet-induced metabolic disorders in rats

Background

Insulin resistance (IR) leads to various metabolic abnormalities, including diabetes mellitus, obesity, nonalcoholic steatohepatitis, and neurodegenerative disorders. Natural products rich in nontoxic phytochemicals are cost-effective and widely used to manage insulin resistance, reducing drug interactions. Artichoke stems and red algae contain several phytochemical compounds that exert antioxidant and anti-inflammatory effects.

Aim

This study aims to explore and compare the preventive and therapeutic effects of red algae and artichoke stem extracts against high-fat diet-induced insulin resistance and then compare their impacts with those of the reference drug metformin, which is commonly used for treating type 2 diabetes.

Methods

The animals were fed a high-fat diet for eight weeks to induce insulin resistance. The plants were then treated orally with 100 mg/kg body weight red algae, artichoke extracts, or metformin per day for 14 days. The protective rat groups received the extracts at the same dose for 14 days before being fed the high-fat diet for eight weeks. Commercial kits and standardized methods were used to measure blood diabetic profiles (glucose, insulin, lipid profile, fructosamine, and retinol-binding protein-4 (RBP-4)) and liver oxidative stress parameters, nuclear factor-κβ (NF-κβ), peroxisome proliferator-activated receptor gamma (PPAR-γ), phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K), retinol-binding protein-4 (RBP-4), and phosphatase and tensin homolog (PTEN).

Results

Our results showed that both extracts inhibited NF-κB and PTEN while enhancing PI3K, RPB-4, and PPAR-γ due to their potent antioxidant properties. They also increased insulin sensitivity, as reflected by reduced blood glucose and lipid profile levels and normalized fructosamine and RBP-4. Additionally, these extracts prevent oxidative stress-induced hepatic and nephric cell dysfunction, as confirmed by improved blood, liver, and kidney parameters.

Conclusion

Therefore, both extracts could be good antioxidant treatments for oxidative stress-related insulin resistance because they restore the balance of the PI3K/PPAR-γ/RBP-4 pathway. This pathway increases glucose uptake, stops gluconeogenesis, speeds up lipid metabolism, and stops the inflammation pathway.

Therapeutic Effects of Nigella sativa Oil and Whole Seeds on STZ-Induced Diabetic Rats: A Biochemical and Immunohistochemical Study

Background

Type II diabetes mellitus (DM) is an increasing health problem that has negative impacts on patients and healthcare systems, worldwide. The development of new therapies with better efficacy, fewer side effects, and lower prices are urgently needed to treat this disease.

Aim

To evaluate and compare the therapeutic effects of Nigella sativa (N. sativa) seed and oil on the biochemical parameters and regeneration of pancreatic islets (or islets of Langerhans) of streptozotocin (STZ)-induced diabetic rats.

Materials and Methods

The diabetic rat model was prepared by administering a single dose of STZ (35 mg/kg body weight). The whole seed or the oil of N. sativa was administered to the diabetic and control groups for a period of 28 days, but not to the negative and STZ controls. Serum blood glucose, liver enzymes, lipid profile, and renal function tests (uric acid, albumin, total protein, urea, and creatinine) were measured in all groups. After the rats were euthanized, their pancreases were extracted, and then sectioned and fixed on slides in preparation before staining with H&E stain and immunohistochemical study.

Results

Treatment of STZ-diabetic rats with N. sativa seeds or oil significantly improved their serum glucose levels, lipid profiles, and liver and renal functions as well as preserved the integrity of pancreatic β cells.

Conclusion

N. sativa seeds and oil demonstrate significant therapeutic improvement effects on DM and its related complications including effective protection of islets of Langerhans. The therapeutic benefits of N. sativa seeds and oil on DM and its related complications are comparable.

The Role of Selenium Nanoparticles in Addressing Diabetic Complications: A Comprehensive Study

Diabetes, as an emerging epidemic, has put forward a significant spotlight on the evolving population worldwide grounded upon the remarkable affliction of healthcare along with economical conflict. Various studies suggested that, in modern society, lack of maintenance of a healthy life style leads to the occurrence of diabetes as insulin resistant, later having a damaging effect on the pancreatic β-cells, suggesting various complications. Furthermore, diabetes management is controversial owing to different opinions based on the prevention of complications. For this purpose, nanostructured materials (NSM) like selenium nanoparticles (SeNPs) have proved their efficiency in the therapeutic management of such serious diseases. This review offers an in- -depth idea regarding the pathophysiology, diagnosis and various conventional therapeutics of type 1 and type 2 diabetes, shedding light on Diabetic Nephropathy (DN), a case study of type 1 diabetes. Moreover, this review provides an exhaustive study by highlighting the economic and healthcare burdens associated with diabetes along with the controversies associated with conventional therapeutic management and the promising role of NSM like selenium nanoparticles (SeNPs), as a novel weapon for encountering such fatal diseases.

Antioxidant and Hypoglycemic Potential of Essential Oils in Diabetes Mellitus and Its Complications

Since the earliest times, essential oils (EOs) have been utilized for medicinal and traditional purposes. However, in recent decades, an increasing interest has developed due to the need to rediscover herbal remedies and adjuvant therapies for the management of various diseases, particularly chronic ones. The present narrative review examines the potential for EOs to exert hypoglycemic and antioxidant effects in diabetes mellitus, analyzing the main publications having evaluated plant species with potentially beneficial effects through their phytocompounds in diabetes mellitus and its complications. Numerous species have shown promising characteristics that can be used in diabetes management. The hypoglycemic effects of these EOs are attributed to their capacity to stimulate glucose uptake, suppress glucose production, and increase insulin sensitivity. Moreover, EOs can alleviate the oxidative stress by manifesting their antioxidant effects via a variety of mechanisms, including the scavenging of free radicals, the regulation of antioxidant enzymes, and the decreasing of lipid peroxidation, due to their diverse chemical composition. These findings demonstrate the possible benefits of EOs as adjuvant therapeutic agents in the management of diabetes and its complications. The use of EOs in the treatment of diabetes shows good potential for the development of natural and effective strategies to enhance the health outcomes of people with this chronic condition, but additional experimental endorsements are required.

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

Introduction

Long used in traditional medicine, Nigella sativa (NS; Ranunculaceae) has shown significant efficacy as an adjuvant therapy for diabetes mellitus (DM) management by improving glucose tolerance, decreasing hepatic gluconeogenesis, normalizing blood sugar and lipid imbalance, and stimulating insulin secretion from pancreatic cells. In this review, the pharmacological and pharmacokinetic properties of NS as a herbal diabetes medication are examined in depth, demonstrating how it counteracts oxidative stress and the onset and progression of DM.

Methods

This literature review drew on databases such as Google Scholar and PubMed and various gray literature sources using search terms like the etiology of diabetes, conventional versus herbal therapy, subclinical pharmacology, pharmacokinetics, physiology, behavior, and clinical outcomes.

Results

The efficiency and safety of NS in diabetes, notably its thymoquinone (TQ) rich volatile oil, have drawn great attention from researchers in recent years; the specific therapeutic dose has eluded determination so far. TQ has anti-diabetic, anti-inflammatory, antioxidant, and immunomodulatory properties but has not proved druggable. DM's intimate link with oxidative stress, makes NS therapy relevant since it is a potent antioxidant that energizes the cell's endogenous arsenal of antioxidant enzymes. NS attenuates insulin resistance, enhances insulin signaling, suppresses cyclooxygenase-2, upregulates insulin-like growth factor-1, and prevents endothelial dysfunction in DM.

Conclusion

The interaction of NS with mainstream drugs, gut microbiota, and probiotics opens new possibilities for innovative therapies. Despite its strong potential to treat DM, NS and TQ must be examined in more inclusive clinical studies targeting underrepresented patient populations.

LC‐MS based metabolite profiling, in‐vitro antioxidant and in‐vivo antihyperlipidemic activity ofNigella sativaextract

The aim of this study was to identify the bioactive phytoconstituents present in the aqueous extract ofNigella sativaand also, to evaluate the antioxidant and antihyperlipidemic activity in Wistar rats. The LC‐MS/MS analysis was assessed for the determination of different bioactive compounds present inN. sativaextract. Total phenolic and flavonoid content were determined by using validated Folin‐Ciocalteu and Aluminum chloride colorimetric methods, respectively. The in‐vitro antioxidant and in‐vivo antihyperlipidemic activity in Wistar rats were also evaluated. Preliminary phytochemical screening of the extract showed the presence of alkaloids, flavonoids, phenols, glycosides, and amino acids in the aqueous extract. The bioactive compounds of the aqueous extract were identified through LC‐MS/MS analysis. The in‐vitro antioxidant activity ofN. sativashowed the highest free radical scavenging capacity in DPPH, H2O2, and OH radical scavenging assays with IC50values 11.916 ± 2.828, 30.294 ± 13.790, and 12.048 ± 2.828 µg/mL, respectively. Evaluation of antihyperlipidemic activity of extract in Wistar rats showed that a high dose (800 mg/kg) of extract significantly decreased total cholesterol (TC) 71.76 ± 6.91 mg/dL, TG 83.6 ± 8.09 mg/dL, low‐density lipoproteins (LDL‐c) 33.86 ± 6.05 mg/dL, very low‐density lipoproteins (VLDL‐c) 16.72 ± 1.61 mg/dL level in blood. However, the HDL‐C level was significantly improved (21.18 ± 1.80 mg/dL) as compared to HFD‐induced control rats (11.76 ± 1.14 mg/dL) after 28 days of treatment. Also, at the same dose, animal body weight was also decreased to 162.6 ± 16.40 g compared with control 184.4 ± 10.24 g. The aqueous extract ofN. sativawas found to be an effective natural source of antioxidant and hypolipidemic agents. This activity was attributed to the presence of diverse bioactive compounds in it.

The Hepatotoxicity of Nigella sativa Oil Linked to the Route of Administration

Background:

Even Nigella sativa oil (NSO) has several pharmacological effects; the route of administration is critical to obtain the desired activity in which intraperitoneal injection (IP) of oil recruits macrophages and induces inflammation.

Objective:

The current study aimed to determine the best administration route of NSO in rats either oral or IP.

Methods:

The components of NSO, routine blood analyses, hepatic oxidative stress and proinflammatory parameters, and liver histopathological study were evaluated.

Results:

NSO contained 32.14% E,E,Z- 1, 3 , 12- nonadecatriene- 5, 14 diol, 25% thymoquinone (TQ) and 3.74% dimethyl sulfoxide (DMSO). In addition, the rats who received IP injection of NSO showed an increase in hepatic enzymes, lipid profiles, oxidative stress, and inflammatory markers. This was associated with hepatic up-regulation of the A disintegrin and metalloproteinase 17 (ADAM- 17) genes, which are corroborated by a reduction in hepatic tissue inhibitor of metalloproteinase 3 (TIMP-3) concentration. These indications were seen in rats given a small amount of DMSO (NSO vehicle), indicating that NSO-oral delivery was safer than IP.

Conclusion:

NSO-IP administration promotes the hepatic oxidative stress-inflammation axis; thus, NSO is a generally safe chemical, especially when administered orally to experimental animals.

Antidiabetic activity of Berberis brandisiana is possibly mediated through modulation of insulin signaling pathway, inflammatory cytokines and adipocytokines in high fat diet and streptozotocin-administered rats

Medicinal plants play a key role in protection of chronic non-communicable ailments like diabetes, hypertension and dyslipidemia. Berberis brandisiana Ahrendt (Berberidaceae) is traditionally used to treat diabetes, liver problems, wounds, arthritis, infections, swelling and tumors. It is also known to be enriched with multiple phytoconstituents including berbamine, berberine, quercetin, gallic acid, caffeic acid, vanillic acid, benzoic acid, chlorogenic acid, syringic acid, p-coumaric acid, m-coumaric acid and ferulic acid. The efficacy of B. brandisiana has not been established yet in diabetes. This study has been planned to assess the antidiabetic activity of B. brandisiana in high fat diet and streptozotocin (HFD/STZ)-induced diabetes using animals. Administration of aqueous methanolic extract of B. brandisiana (AMEBB) and berbamine (Berb) for 8 weeks caused a dose dependent marked (p < 0.01) rise in serum insulin and HDL levels with a significant decline (p < 0.01) in glucose, triglycerides, glycosylated hemoglobin (HbA1c), cholesterol, LDL, LFTs and RFTs levels when compared with only HFD/STZ-administered rats. AMEBB and Berb also modulated inflammatory biomarkers (TNF-α, IL-6) and adipocytokines (leptin, adiponectin and chemerin). AMEBB (150 mg/kg and 300 mg/kg) and Berb (80 mg/kg and 160 mg/kg) treated rats showed a marked increase (p < 0.001) in catalase levels (Units/mg) in pancreas (42.4 ± 0.24, 47.4 ± 0.51), (38.2 ± 0.583, 48.6 ± 1.03) and liver (52 ± 1.41, 63.2 ± 0.51), (57.2 ± 0.58, 61.6 ± 1.24) and superoxide dismutase levels (Units/mg) in pancreas (34.8 ± 1.46, 38.2 ± 0.58), (33.2 ± 0.80, 40.4 ± 1.96) and liver (31.8 ± 1.52, 36.8 ± 0.96), (30 ± 0.70, 38.4 ± 0.81),respectively while a significant (p < 0.01) decrease in serum melondialdehyde levels (nmol/g) in pancreas (7.34 ± 0.17, 6.22 ± 0.22), (7.34 ± 0.20, 6.34 ± 0.11) and liver (9.08 ± 0.31,8.18 ± 0.29), (9.34 ± 0.10, 8.86 ± 0.24) compared to the data of only HFD/STZ-fed rats. Histopathological studies of pancreas, liver, kidney, heart and aorta revealed restoration of normal tissue architect in AMEBB and Berb treated rats. When mRNA expressions of candidate genes were assessed, AMEBB and Berb showed upregulation of IRS-1, SIRT1, GLUT-4 and downregulation of ADAM17. These findings suggest that AMEBB and Berb possess antidiabetic activity, possibly due to its effect on oxidative stress, glucose metabolism, inflammatory biomarkers and adipocytokines levels. Further upregulation of IRS-1, SIRT1, GLUT-4 and downregulation of ADAM17, demonstrated its potential impact on glucose homeostasis, insulin resistance and chronic inflammatory markers. Thus, this study provides support to the medicinal use of B. brandisiana and berbamine in diabetes.

Potential health benefits of Nigella sativa on diabetes mellitus and its complications: A review from laboratory studies to clinical trials

This review aims to gather and summarize up-to-date information on the potential health benefits of Nigella sativa (NS) on diabetes mellitus (DM) and its complications from different animal models, clinical trials and in vitro studies. DM is one of the most prevalent metabolic disorders resulting from chronic hyperglycaemia due to problems in insulin secretion, insulin action or both. It affects people regardless of age, gender and race. The main consequence of DM development is the metabolic dysregulation of glucose homeostasis. Current treatments for DM include pharmacological therapy, insulin and diabetic therapy targeting β cells. Some of these therapeutic approaches are promising; however, their safety and effectiveness remain elusive. Since ancient times, medicinal plants have been used and proven effective against diseases. These plants are believed to be effective and benefit physiological and pathological processes, as they can be used to prevent, reduce or treat multiple diseases. Nigella sativa Linn. is an annual indigenous herbaceous plant belonging to Ranunculaceae, the buttercup family. NS exhibits multifactorial activities; it could ameliorate oxidative, inflammatory, apoptotic and insulinotropic effects and inhibit carbohydrate digestive enzymes. Thus, this review demonstrates the therapeutic potential of NS that could be used as a complement or adjuvant for the management of DM and its complications. However, future research should be able to replicate and fill in the gaps of the study conducted to introduce NS safely to patients with DM.

Nigella sativa L. and Its Active Compound Thymoquinone in the Clinical Management of Diabetes: A Systematic Review

Despite existing conventional hypoglycemic drugs to manage diabetes, their non-availability and cost in low-income countries coupled with the associated side effects remain a major concern. Consequently, exploring for alternative treatments to manage diabetes has been a continuous priority. Nigella sativa L. (NS) (Family: Ranunculaceae) is regarded as a valuable traditional remedy in diabetes management and extensively studied for its biological properties. This systematic review provides a comprehensive and critical analysis of clinical studies on the efficacy, safety, and mechanism of action of NS and its compound thymoquinone (TQ) in diabetes management. The main scientific databases which were scrutinised were Scopus, PubMed, Google Scholar, and Web of Science. Data search was conducted from inception to January 2022. A total of 17 clinical studies were obtained; 16 studies on Nigella sativa L. and 1 study on its compound TQ. N. sativa was found to be highly potent in terms of its hypoglycemic activity when compared to placebo based on improvement in parameters including fasting blood glucose (FBG), postprandial blood glucose (PPBG), Hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and homeostatic model assessment for assessment of beta-cell functionality (HOMA-β). The compound TQ in combination with a daily dose of metformin demonstrated a greater reduction in the levels of HbA1c and blood glucose compared to metformin alone. The bioavailability of TQ can be enhanced by using nanoparticulate drug delivery systems. Considering the findings of the clinical studies along with negligible adverse effects, NS has strong potential application in bioproduct development for the management of diabetes. Further investigations should explore the detailed mechanism of actions by which TQ exerts its therapeutic antidiabetic effects to provide more insights into its clinical use in the management of diabetes.

Effects of two triterpenoids from Nigella sativa seeds on insulin resistance of 3T3-L1 adipocytes

Insulin resistance (IR) is a physiological abnormality that occurs when insulin fails to activate the signal transduction pathway in target organs. It was found that supplementation of Nigella sativa seeds with oral antidiabetic medicines helps improve blood glucose control by enhanced β cells activity and alleviation of IR. However, the activities and related mechanisms of phytochemicals from N. sativa seeds have not been thoroughly explored. In this study, the effects of two triterpenoids, 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1→4)-β-D-glucopyranose-L-(1→6)-β-D-glucopyranose]-hederagenin (Hxrarg) and 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-hederagenin (Hxra), on IR were studied by 3T3-L1 adipocytes model. The results demonstrated that Hxrarg and Hxra inhibited maturation of 3T3-L1 preadipocytes, dramatically stimulated glucose uptake of IR-3T3-L1 adipocytes, promoted transcription of IRS, AKT, PI-3K, and GLUT4 mRNA. Western Blot results suggested that Hxrarg and Hxra were able to markedly up-regulate expression of p-IRS, p-AKT, PI-3K, and GLUT4 proteins. These findings could provide a basic foundation for the continued development and application of N. sativa in medicine and functional foods.

Effect of Nigella Sativa Oil on Oxidative Stress, Inflammatory, and Glycemic Control Indices in Diabetic Hemodialysis Patients: A Randomized Double-Blind, Controlled Trial

Background and Aims

Diabetes is a leading cause of renal failure. High levels of oxidative stress and inflammation in patients with renal diabetes lead to various disorders and mortality. This study was performed to determine the effect of Nigella sativa (NS) supplementation on superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP), glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), and insulin (INS) in patients with diabetes mellitus undergoing hemodialysis (HD).

Methods

In this randomized, double-blind, placebo-controlled clinical trial, a total of 46 diabetic HD patients were randomly divided into NS (n = 23) and placebo (n = 23) groups. NS group received 2 g/day of NS oil, and the placebo group received paraffin oil for 12 weeks. Serum levels of SOD, MDA, TAC, hs-CRP, HbA1C, FBS, and INS were measured before and after the study.

Results

Compared to baseline values, SOD, TAC, and INS levels increased, whereas MDA, hs-CRP, HbA1c, and FBS significantly decreased. After adjusting for covariates using the ANCOVA test, changes in the concentrations of SOD (p = .040), MDA (p = .025), TAC (p=<.001), hs-CRP (p = .017), HbA1c (p = .014), and FBS (p = .027) were statistically significant compared to the placebo group. Intergroup changes in INS were not significant. Additionally, there were no notable side effects during the research.

Conclusions

This study found that NS supplementation significantly enhanced the levels of SOD, MDA, TAC, hs-CRP, HbA1c, and FBS in diabetic HD patients.

Effect of Tithonia diversifolia Leaf Extract on Leptin, Adiponectin, and Insulin Receptor Levels in Diabetic Rats

This study aimed to evaluate the effect of Tithonia diversifolia extract (TDE) on leptin, adiponectin, and insulin receptor (IR) concentrations in diabetic rats. Twenty-four Wistar rats were divided into a control and treatment groups (n=6 per group). The control group received normal saline, and the treatment groups received 0.25% sodium carboxymethyl cellulose, TDE at 100 mg/kg body weight (bw), and catechin at 10 mg/kg bw for 7 days. On day 8, the rats were sacrificed, blood samples were obtained, and leptin, adiponectin, and insulin concentrations were measured using avidinhorseradish peroxidase sandwich-enzyme-linked immunosorbent assay. A calorimetric method was used to measure blood glucose (BG) and total serum cholesterol concentrations. The pancreas and kidneys were collected for the measurement of renal IR and macrophage cluster of differentiation (CD)14 levels using immunohistochemical staining. Acute type 2 diabetes mellitus (T2DM) with elevated BG and total serum cholesterol concentrations was observed in the treatment groups administered streptozotocin. The administration of TDE at 100 mg/kg bw significantly decreased leptin and increased adiponectin concentrations (P≤0.05). Furthermore, TDE treatment significantly increased renal IR and decreased macrophage CD14 levels (P<0.05). Therefore, TDE decreased leptin and BG concentrations by increasing IR levels. TDE also suppressed the necrosis of pancreatic tissues by inhibiting macrophage CD14 expression in diabetic rats. However, further research is necessary to determine the effect of TDE on interleukin and IR levels in the related tissues of patients with T2DM.

PI3K-AKT Pathway Modulation by Thymoquinone Limits Tumor Growth and Glycolytic Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of death in men and the fourth in women worldwide and is characterized by deranged cellular energetics. Thymoquinone, an active component from Nigella sativa, has been extensively studied against cancer, however, its role in affecting deregulated cancer metabolism is largely unknown. Further, the phosphoinositide 3-kinase (PI3K) pathway is one of the most activated pathways in cancer and its activation is central to most deregulated metabolic pathways for supporting the anabolic needs of growing cancer cells. Herein, we provide evidence that thymoquinone inhibits glycolytic metabolism (Warburg effect) in colorectal cancer cell lines. Further, we show that such an abrogation of deranged cell metabolism was due, at least in part, to the inhibition of the rate-limiting glycolytic enzyme, Hexokinase 2 (HK2), via modulating the PI3/AKT axis. While overexpression of HK2 showed that it is essential for fueling glycolytic metabolism as well as sustaining tumorigenicity, its pharmacologic and/or genetic inhibition led to a reduction in the observed effects. The results decipher HK2 mediated inhibitory effects of thymoquinone in modulating its glycolytic metabolism and antitumor effects. In conclusion, we provide evidence of metabolic perturbation by thymoquinone in CRC cells, highlighting its potential to be used/repurposed as an antimetabolite drug, though the latter needs further validation utilizing other suitable cell and/or preclinical animal models.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Therapeutic Screening of Herbal Remedies for the Management of Diabetes

The study of diabetes mellitus (DM) patterns illustrates increasingly important facts. Most importantly, they include oxidative stress, inflammation, and cellular death. Up to now, there is a shortage of drug therapies for DM, and the discovery and the development of novel therapeutics for this disease are crucial. Medicinal plants are being used more and more as an alternative and natural cure for the disease. Consequently, the objective of this review was to examine the latest results on the effectiveness and protection of natural plants in the management of DM as adjuvant drugs for diabetes and its complex concomitant diseases.

Effects of omega-3 fatty acids and metformin combination on diabetic cardiomyopathy in rats through autophagic pathway

Diabetic cardiomyopathy is a primary cause of increased morbidity and mortality in diabetics. Evidence has suggested a pivotal role for interrupted mitochondrial dynamics and quality control machinery in the onset and development of diabetic cardiomyopathy. Sequestosome 1 (SQSTM1) is a major reporter of selective autophagic activity. Other than controlling the expression of genes involved in mitochondrial biogenesis, recently peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) was reported to directly affect SQSTM1 gene expression. Calcineurin, a pivotal mediator of cardiac hypertrophy, has been also linked to enhanced expression of SQSTM1. This study aimed to test the cardioprotective effects of adding ω-3 polyunsaturated fatty acids (PUFAs) to metformin in a rat model of type 2 diabetes mellitus and to evaluate the molecular mechanisms underlying their effects on mitochondrial quality. Diabetes was induced in male Sprague Dawley rats by a high-fat diet for 6 weeks, followed by a low-dose streptozotocin (35 mg/kg). Diabetic rats were either treated with metformin (150 mg/kg/d), ω-3 PUFAs (300 mg/kg/d), or their combination in the same doses for further 8 weeks. Along with metabolic and pathological derangements, we report that correlating with electron microscopic evidence of mitochondrial degeneration, gene expression of the autophagic indicators SQSTM1, PGC-1α, and calcineurin were decreased in the hearts of diabetic rats. Independent of its anti-hyperglycemic effects, metformin successfully preserved mitochondrial integrity and upregulated myocardial PGC-1α, calcineurin, and SQSTM1 gene expression. ω-3 PUFAs possess synergistic cardioprotection when added to metformin, suggested by improvements in myocardial ultrastructure, autophagic activity, and SQSTM1 gene expression.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Dual prophylactic/therapeutic potential of date seed, and nigella and olive oils-based nutraceutical formulation in rats with experimentally-induced Alzheimer's disease: A mechanistic insight

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a multifactorial etiology and significantly increasing incidence during the last decade. Hence, developing an effective therapy is crucial for public health. The current study aimed to examine the dual prophylactic/therapeutic potential of a nutraceutical formula based on aqueous extract of roasted date seeds, and nigella and virgin-olive oils against experimentally-induced Alzheimer's disease in rats. Alzheimer's disease-like pathology was induced in male Wistar rats using oral CuSO₄ (200 mg/Kg/day for two months). The nutraceutical formula was given orally to experimental animals (10 mL/kg/d) for 14 days before (as prophylaxis) and after Alzheimer's disease induction and its therapeutic effect in both cases is tested in comparison to donepezil (0.5 mg/kg/d). The nutraceutical formula was found to ameliorate the CuSO₄-induced neuronal damage and regenerate the affected hippocampus tissue and significantly improvemed in learning ability. The formula was also effective in decreasing brain amyloid-β, tau protein, TNF-α level, iNOS level in hippocampus, oxidative stress level, and inhibiting acetylcholinesterase activity and expression in brain and hippocampus, respectively. Further, an increase in GSH levels, activities of SOD, and GST and levels of hippocampus ADAM 17 and brain phospholipids was observed. In conclusion, the studied nutraceutical formula is proved to be effective in ameliorating Alzheimer's neurodegenerative progression with added-prophylactic potential.

Recent Progress on Chemical Constituents and Pharmacological Effects of the Genus Nigella

Seeds of the genus Nigella plants as folk medicine are often used to prevent and treat asthma, diarrhea, dyslipidemia, and other diseases around the world. Pharmacological researches showed that seed extract and seed oil have antibacterial, antioxidant, hypoglycemic, and hepatoprotective effects which attributed to their bioactive constituents such as alkaloids, saponins, flavones, and phenols. This paper has covered recent progresses on chemical and pharmacological researches on these plants, including their compounds and pharmacological effects. It was found that the chemical component researches were focused on the seed oil. Therefore, more attention should be paid to the profile of the whole constituents in the seeds.

Effect of Nigella sativa oil supplement on risk factors for cardiovascular diseases in patients with type 2 diabetes mellitus

This study aimed to evaluate the effects of Nigella sativa oil on serum level of systemic inflammation, oxidative stress, fasting blood glucose (FBG), and lipid profile in patients with type 2 diabetes mellitus (T2DM). This double-blind randomized clinical trial study was based on 50 patients with T2DM. Patients were allocated randomly to either N. sativa oil or placebo groups. The intervention group received 1,000 mg N. sativa oil as two capsules, daily for 8 weeks, whereas the placebo group received a corresponding placebo. At baseline and the end of the study, 5 ml blood was collected from each patient after 14-hour fasting for measuring serum C-reactive protein (hs-CRP), malondialdehyde (MDA), FBS, and lipid profile. Analyses covariance was performed to compare investigated parameters between two groups, controlled for relevant covariates. Using N. sativa supplement was significantly associated with decrease in FBS (p < .001), triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein cholesterol (p < .001), serum hs-CRP, MDA (p < .001) and increase in serum level of high-density lipoprotein cholesterol (p < .001) in intervention group compared with placebo group. Nigella sativa oil supplement has cardiovascular protective effects in patients with T2DM, by improving the lipid profile and glycemia, by reducing the C-reactive protein level and the lipid peroxidation.

The functional nutritional and regulatory activities of calcium supplementation from eggshell for obesity disorders management

The present study was to investigate the effective role of renewable sources of Ca⁺² from eggshell (ES) with different doses to restrict obesity disorders. Rats were classified as follows, G₁ : normal diet for 26 weeks; G₂ : high-fat diet (HFD) for 26 weeks; G₃ , G₄ , and G₅ were supplemented with HFD for 16 weeks and treated with 7.2 g Ca⁺² ES/Kg rat chow, 18 g Ca⁺² ES/Kg rat chow, and 2% diet containing fat (DCF), respectively, for the remaining 10 weeks. Results revealed a significant effect of the low dose of Ca⁺² supplement in form of ES than high dose and 2% DCF; on basis of anthropometric parameters, lipid, leptin, adiponectin, thyroid hormones, Ca⁺² , 25-hydroxyl vitamin-D, and oxidative and inflammatory parameters were regulated. Results were confirmed with the histopathological study. Therefore, it was concluded that Ca⁺² supplementation can be used as a beneficial source for obesity management with anticholesterol actions. PRACTICAL APPLICATIONS: Obesity represented public health hazards. The eggshell is one of the waste products that contain a high percentage of Ca⁺² . The current data exposed using a low dose of ES as a new source of Ca⁺² supplement for treatment of HFD rats leads to significant enhancement of lipid profiles, liver enzymes, kidney functions, leptin, adiponectin, Ca⁺² , 25(OH)-D, TSH, fT_4, and PTH levels. Also, there was a reduction in weight gain, Bwt, BMI, BG, insulin, and HOMA-IR. Moreover, the oxidant-pro-oxidant system was improved in both hepatic and adipose tissues where NO and TBARS concentrations were diminished, and SOD specific activity was elevated. Additionally, TNF-α and ADAM17 expression were downregulated. Hence, it was concluded that there was good evidence that diets supplemented with ES were associated with the reduction of obesity complications especially regulating fat processing and storage in the body.

Metformin and Berberine suppress glycogenolysis by inhibiting glycogen phosphorylase and stabilizing the molecular structure of glycogen in db/db mice

Glycogen is a branched glucose polymer involved in sustaining blood glucose homeostasis. Liver glycogen comprises α particles (up to 300 nm in diameter) made of joined β particles (∼20 nm in diameter). Glycogen α particles in a mouse model for diabetes are molecularly fragile, breaking down into smaller β particles more readily than in healthy mice. Glycogen phosphorylase (GP), a rate-limiting enzyme in glycogen degradation, is overexpressed in diabetic mice. This study shows that Metformin and Berberine, two common drugs, two common drugs used to treat diabetes, are able to revert the liver glycogen of diabetic mice to the stable structure seen in non-diabetic mice. It is also shown that these drugs reduce the GP level via the cAMP/PKA signaling pathway in diabetic livers and decrease the affinity of GP with the glycogen of db/db mice. These effects of these drugs may slow down the degradation of liver glycogen and improve glucose homeostasis.

Green synthesis of silver nanoparticles by Nigella sativa extract alleviates diabetic neuropathy through anti-inflammatory and antioxidant effects

Green synthesis of silver nanoparticles has gained great interest among scientists. In view of this data, we conducted this study to identify the ameliorative effect of green synthesis of silver nanoparticles using Nigella sativa extract in diabetic neuropathy induced experimentally. In this study, 50 adult male albino rats were used and they were randomly divided into five groups; the first group was the healthy control group, the second group were the diabetic neuropathy diabetic neuropathy induced, Groups (3-6) diabetic neuropathy induced group and treated with silver nanoparticles, Nigella sativa extract and green synthesized silver nanoparticles using Nigella sativa extract respectively. Biochemical parameters including diabetic, inflammatory and antioxidant biomarkers were evaluated. Brain histopathology was also performed. Results revealed substantial rise in glucose, AGE, aldose reductase with insulin reduction in diabetic neuropathy induced group as compared to healthy control. Also, inflammatory markers increased significantly in diabetic neuropathy induced group. A remarkable change in oxidative status was observed in the same group. Furthermore, significant decline in nitrotyrosin level was observed. Regarding gene expression, we found significant down regulation in brain TKr A accompanied by upregulation of nerve growth factor in diabetic neuropathy group comparing with healthy control. Several treatments for diabetic neuropathy remarkably ameliorate all the investigated biomarkers. Histological findings are greatly relied on for the results achieved in this study. Therefore, it can be established that green synthesis of silver nanoparticles in combination with Nigella sativa extract could be a newly neuroprotective agents against inflammation and oxidative stress characterizing diabetic neuropathy through their antidiabetic, anti-inflammatory and anti-oxidants effects.

Synergistic effect of nano-selenium and metformin on type 2 diabetic rat model: Diabetic complications alleviation through insulin sensitivity, oxidative mediators and inflammatory markers

BACKGROUND AND OBJECTIVES

In the present article, we explore a novel strategy of selenium nanoparticles (Se-NPs) for the treatment of type 2 diabetes mellitus (T2DM) by investigating the effect of Se-NPs alone and in combination with standard anti-diabetic drug metformin (MET) in high-fat diet/streptozotocin (HFD/STZ)-induced T2DM.

METHODS

HFD was supplemented daily to experimental rats for 8 weeks, followed by a single low dose injection of 35 mg/kg of STZ to induce T2DM. The synergistic effect of the different therapeutic strategies on diabetic complications was evaluated after the Se-NPs and MET administration for 8 weeks. Molecular and biochemical analyses were conducted to figure out the effectiveness of our treatment on insulin sensitivity, oxidative mediators and inflammatory markers.

RESULTS

Our observations demonstrated that HFD/STZ-induced rats have a toxic effect on serum and hepatic tissues resulted in inducing remarkable oxidative damage and hyper-inflammation with a significant disturbance in the insulin signaling pathway. Experimental animals either treated with mono-therapeutic-two doses Se-NPs (0.1 and 0.4 mg/kg) and/or MET (100 mg/kg) alone as well as the combined therapy resulted in a remarkable protective anti-diabetic effect illustrated by significant decreases in fasting blood glucose and insulin levels after 8 weeks treatment. At the same time, the levels of active insulin signaling proteins pIRS1/pAKT/pGSK-3β/pAMPK were significantly improved. Moreover, Se-NPs exhibited an anti-inflammatory effect by the mitigation of cytokine expression and a balance between oxidative stress and antioxidant status was restored. Furthermore, the anti-diabetic drug MET administration also exhibited a significant improvement in diabetic complications after the treatment period.

CONCLUSION

This study provides mightily the mechanism of action of combined Se-NPs and MET as a promising therapeutic alternative that synergistically alleviates most of diabetic complications and insulin resistance.

Black Seed Thymoquinone Improved Insulin Secretion, Hepatic Glycogen Storage, and Oxidative Stress in Streptozotocin-Induced Diabetic Male Wistar Rats

Diabetes mellitus is one of the metabolic diseases having several complications. Nigella sativa oil (NSO) might have beneficial effects in the treatment of diabetic complications. Thirty-two mature male Wistar rats were equally divided into four experimental groups: control, control NSO 2 mL/kg, streptozotocin- (STZ-) induced diabetic, and diabetic (STZ-induced) treated with oral NSO 2 mg/kg for 30 days. Fasting blood glucose (FBG), insulin, and lipid profile levels were determined. Pancreatic and hepatic tissues were used for catalase and GSH. Histopathology, hepatic glycogen contents, insulin immunohistochemistry, and pancreatic islet morphometry were performed. NSO 2 mL/kg was noticed to decrease (P < 0.05) FBG and increase (P < 0.05) insulin levels in diabetic rats than in diabetic nontreated animals. Lipid profile showed significant (P < 0.5) improvement in diabetic rats that received NSO 2 mL/kg than in the diabetic group. Both pancreatic and hepatic catalase and GSH activities revealed a significant (P < 0.05) increment in the diabetic group treated with NSO than in the diabetic animals. NSO improved the histopathological picture and hepatic glycogen contents of the diabetic group as well as increased (P < 0.05) insulin immunoreactive parts % and mean pancreatic islet diameter. NSO exerts ameliorative and therapeutic effects on the STZ-induced diabetic male Wistar rats.

Dissecting the Potential Roles of Nigella sativa and Its Constituent Thymoquinone on the Prevention and on the Progression of Alzheimer's Disease

Several nutraceuticals have been investigated for preventing or retarding the progression of different neurodegenerative diseases, including Alzheimer's disease (AD). Because Nigella sativa (NS) and its isolated compound thymoquinone (TQ) have significant anti-oxidant and anti-inflammatory proprieties, they could represent effective neuroprotective agents. The purpose of this manuscript is to analyze and to recapitulate the results of in vitro and in vivo studies on the potential role of NS/TQ in AD's prevention and treatment. The level of evidence for each included animal study has been assessed by using a modified CAMARADES (Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies) 10-item checklist. We used MEDLINE and EMBASE databases to screen relevant articles published up to July 2017. A manual search was also performed. The database search yielded 38 studies, of which 18 were included in this manuscript. Results from these approaches suggest that NS or TQ could represent an effective strategy against AD due to the balancing of oxidative processes and the binding to specific intracellular targets. The overall effects mainly regard the prevention of hippocampal pyramidal cell loss and the increased cognitive functions.

Improvement of antihyperglycemic activity of nano-thymoquinone in rat model of type-2 diabetes

Thymoquinone is a bioactive constituent of Nigella sativa seeds. It has been reported to possess antihyperglycemic effect in rats. However, the effect of nanoformulation (NF) of thymoquinone has not been reported in literature. So, the present study was designed with the aim to investigate the effect of nanoformulation of thymoquinone in streptozotocin-nicotinamide induced type-2 diabetic rats and compare its effect with pure bioactive compound as well as metformin, a standard antidiabetic drug. It is the first study reporting the use of thymoquinone NF against diabetes. Polymeric nanocapsules (NCs) of thymoquinone and metformin were prepared by nanoprecipitation method using gum rosin, a biocompatible polymer. Box-Behnken statistical analysis tool was used for the optimization of polymer and other excipients. The NCs were then characterized with respect to particle size, stability, morphology, and in vitro drug dissolution profiles. Furthermore, thymoquinone (20, 40 & 80 mg/kg), metformin (150 mg/kg) and their nanoformulations (20, 40 & 80 mg/kg for thymoquinone and 80 mg/kg for metformin) per se were administered for 21 successive days to type-2 diabetic rats. Body weight and blood glucose levels were measured every week for 3 weeks. Serum lipid profile and glycosylated hemoglobin were estimated on 22^nd day. The nanocapsules were stable, spherical in shape and size was less than 100 nm. Thymoquinone-and metformin-loaded NCs showed sustained release profile as compared to their pure forms. Oral administration of thymoquinone, metformin and their nanoformulations significantly decreased blood glucose level and glycated haemoglobin; and improved the lipid profile of diabetic rats as compared to diabetic control rats. Thymoquinone-loaded NCs (containing 10, 20 and 40 mg of thymoquinone) produced dose-dependent antihyperglycemic effect and this effect was comparable to thymoquinone and metformin. In conclusion, thymoquinone nanocapsules (actually containing half of the doses of thymoquinone) produced better antihyperglycemic effect in type-2 diabetic rats as compared to thymoquinone alone.

A nutraceutical combination of Cinnamomum cassia &Nigella sativa for Type 1 diabetes mellitus

Background

Nigella sativa (black cumin) and Cinnamomum cassia (Cinnamon) are an integral part of the Indian diet, and have also been sourced in the ayurveda, the traditional Indian system of medicine, for their medicinal properties. Both the herbs individually have been successfully evaluated for their preliminary antidiabetic potential.

Objective

Herein, we dived deeper into antidiabetic properties of these herbs, by investigating the combinatorial effect of both herbs, on parameters of diabetes and further, as an adjunct to metformin therapy, for assessing the pharmacodynamics of herb-drug interaction in diabetes mellitus. The objectives were to screen the combinatorial extract of Nigella sativa & Cinnamomum cassia’s (NSCCe) alone and in combination with metformin for its potential in mitigating symptoms of diabetes mellitus-alone, and as an adjunct therapy with metformin.

Materials and methods

Diabetes was induced in the animals by a single intraperitoneal injection of streptozotocin. Animals were divided into seven groups with 6 animals each: Vehicle control, Negative control, Positive control (Metformin 50 mg/kg), treatment groups 4 and 5 received NSCCe at the doses of 100 mg/kg and 200 mg/kg, respectively. Groups 6 and 7 received the same doses, in combination with Metformin (50 and 25 mg/kg). Following a 28-day dosing period, plasma glucose levels, lipid profile and renal function profile were evaluated. Histopathological examinations were performed to measure any morphological change in kidney, liver and pancreatic tissue.

Results

Combination of Nigella sativa & Cinnamomum cassia extracts significantly normalized plasma glucose levels, lipid profile and kidney function parameters, compared to the diabetic control group. Animals treated with the combinatorial extract and metformin showed more prominent effects on these parameters. Significant reversal in the pancreatic cell damage was observed on treatment with NSCCe.

Conclusion

This study generates evidence to support Nigella sativa & Cinnamomum cassia as an adjunctive in diabetes treatment protocols.

Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials

Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.

Oxidative stress and expression of insulin signaling proteins in the brain of diabetic rats: Role of Nigella sativa oil and antidiabetic drugs

BACKGROUND AND OBJECTIVES

Insulin resistance of the brain is a specific form of type2-diabetes mellitus (T2DM) and the active insulin-signaling pathway plays a neuroprotective role against damaging conditions and Alzheimer's progression. The present study identifies the mediated emerging effects of the Nigella sativa oil (NSO) on the memory enhancing process, its anti-oxidative, acetylcholinestrase (AChE) inhibition, anti-brain insulin resistance and anti-amyloidogenic activities. In addition, the possible role of some anti-diabetic drugs in the neuro-protection processes and their effect in combination with NSO and/or the insulin receptor inhibitor IOMe-AG538 were investigated.

METHODS

T2DM-induced rats were orally and daily administrated 2.0 ml NSO, 100 mg metformin (MT), 0.8 mg glimepiride (GI) and different combinations (100 mg MT & 2.0 ml NSO, 0.8 mg GI & 2.0 ml NSO and 2.0 ml NSO & intraperitoneal injection of 1/100 LD50 of IOMe-AG538) per kg body weight for 21 days.

RESULTS

A significant increase in the brain lipid peroxidation and decrease in the antioxidant status with peripheral and central production of pro-inflammatory mediators were observed in diabetes-induced rats. The brain AChE was activated and associated with diminished brain glucose level and cholinergic function. In addition, the brain insulin resistance and the attenuated insulin signaling pathway (p-IRS/ p-AKT/p-GSK-3β) were accompanied by an augmentation in GSK-3β level, which in turn may contribute in the extensive alterations of Tau phosphorylation along with changes in PP2A level. Furthermore, neuronal loss and elevation in Aβ-42 plaque formation were observed due to a low IDE formation and an increased expression of p53, BACE1 and APP with diminished ADAM10, SIRT1 and BDNF levels. The expression profile of AD-related miRNAs in sera and brain tissues displayed its neuro-protection role. The treatment of diabetes-induced rats with NSO and the anti-diabetic drugs alone and/or in combination have the potential to suppress the oxidative stress, the pro-inflammatory mediators and amyloidogenic pathway. Moreover, it lowers the insulin receptor inhibitory effect of IOMe-AG538 and modifies the insulin-signaling pathway. Therefore, it prevents the neurotoxicity, amyloid plaque formation and Tau hyper-phosphorylation and restores AD-related miRNA normal levels.

CONCLUSION

These data suggest that NSO or its combined treatments with anti-diabetic drugs have a possible benefit as disease modifying agents for the insulin resistance in the brain through enhancing brain insulin signaling pathway.