BACKGROUND:

Nigella sativa fixed (NSFO) and essential (NSEO) oils have been used to treat diabetes mellitus and its complications. Present study was undertaken to explore and validate these folkloric uses.

METHODS:

Sprague dawley rats having streptozotocin (STZ) induced diabetes mellitus were used to assess the role of NSFO and NSEO in the management of diabetes complications. Parameters investigated were antioxidant potential, oxidative stress, and the immunity by in vivo experiments.

RESULTS:

The results indicated that STZ decreased the glutathione contents (25.72%), while NSFO and NSEO increased the trait significantly (P”‰<”‰0.05). Experimental diets increased the tocopherol contents (P”‰<”‰0.01) and enhanced the expression of hepatic enzymes (P”‰<”‰0.01). Correlation matrix further indicated that antioxidant potential is positively associated (P”‰<”‰0.05) responsible for the modulation of hepatic enzymes and the decrease of the nitric oxide production thus controlling the diabetes complications.

CONCLUSIONS:

Overall, results of present study supported the traditional use of N. sativa and its derived products as a treatment for hyperglycemia and allied abnormalities. Moreover, N. sativa fixed and essential oils significantly ameliorate free radicals and improve antioxidant capacity thus reducing the risk of diabetic complications.

In the recent era, diabetes mellitus has emerged as one of the significant threats to public health and this situation demands the attention of the researchers and allied stakeholders. Dietary regimens using functional and nutraceutical foods are gaining wide range of acceptance and some traditional medicinal plants are of considerable importance. The main objective of this instant study was to explore the antidiabetic potential ofNigella sativa fixed oil (NSFO) and essential oil (NSEO). Three experimental groups of rats received diets during the entire study duration, that is, D1 (control), D2 (NSFO: 4.0%), and D3 (NSEO: 0.30%). Experimental diets (NSFO & NSEO) modulated the lipid profile, while decreasing the antioxidant damage. However, production of free radicals, that is, MDA, and conjugated dienes increased by 59.00 and 33.63%, respectively, in control. On the contrary, NSFO and NSEO reduced the MDA levels by 11.54 and 26.86% and the conjugated dienes levels by 32.53 and 38.39%, respectively. N. sativa oils improved the health and showed some promising anti-diabetic results.

Diabetes is a chronic metabolic problem closely related to cardiovascular disease leading to premature death. Dyslipidemia is an important risk factor responsible for cardiovascular disease in patients with diabetes. This paper is based on review of articles published to observe the effect of N. Sativa (black seed) on lipid levels in patients suffering from Diabetes Mellitus. A search of indexed papers and clinical trials was done using MEDLINE and PubMed and Cochrane search engine. All studies assessing the effect of N. Sativa ingestion on lipid levels among diabetics (animal or human) were included. A total of 12 trials (6 human studies and 6 animal studies) fulfilling the inclusion criteria were reviewed. Majority of human and animal trials done among humans and animals with diabetes or metabolic syndrome demonstrated reduction in weight and improvement in serum lipid levels including decrease total lipids, triglycerides, LDL levels. However, increase in HDL level showed questionable results. N. Sativa L and its different preparations can be used as an adjuvant with lipid lowering drugs for control of lipids however its role as a main therapeutic agent cannot be recommended and more metanalysis using standardized preparations with a close watch on methodological short falls is suggested to prove its role.

BACKGROUND:

Thymoquinone (TQ) is the most abundant and active ingredient of Nigella sativa (NS) seeds. Its hepatic, renal, and cardiac protective effects have been demonstrated in animal models. Streptozotocin (STZ) is an antibiotic that is widely used experimentally as an agent capable of inducing insulin-dependentdiabetes mellitus (IDDM), also known as type I diabetes mellitus (T1DM).

OBJECTIVES:

This study was carried out in an attempt to highlight the possible beneficial effects of TQ in STZ-induced diabetes in rats and to determine the predictive value of mesenchymal and epithelial markers in the response of diabetic nephropathy to TQ.

MATERIALS AND METHODS:

Sixty adult male albino rats were divided in 3 groups: control, diabetic untreated, and diabetic treated with TQ.

RESULTS:

Diabetic rats exhibited morphological changes in both renal glomeruli and tubules with immunohistochemical expression of the mesenchymal markers Fsp1, desmin, and MMP-17 and disappearance of the epithelial marker ZO-1 largely in the glomeruli of diabetic kidneys. Treatment with TQ significantly attenuated renal morphological and immunohistochemical changes in STZ-induced diabetic rats.

CONCLUSIONS:

Thymoquinone has protective effects on experimental diabetic nephropathy. Both mesenchymal and epithelial markers serve as excellent predictors of early kidney damage and indicators of TQ responsiveness in STZ-induced diabetic nephropathy.

Many studies have demonstrated evidence of the health benefits of natural products. Plant extracts have been tested on a variety of physiological disorders, including diabetes mellitus. Studies have tested aqueous extracts, plant fractions extracts, families of active of compounds, and specific active compounds. In this review, we describe the antidiabetic effects of vegetable oils. Information was collected from ScienceDirect and PubMed databases using the following key words: Diabetes mellitus, Oils, Vegetable oils, Type 1diabetes, type 2 diabetes, antidiabetic effect, antihyperglycemic, antidiabetic oil. We have compiled approximately ten vegetable oils with including experimental studies that have demonstrated benefits ondiabetes mellitus. There are soybean, argan, olive, palm, walnut, black cumin, safflower, Colocynth, Blackseed, Rice bran, Cinnamom, and Rocket oils. For each vegetable oil, we investigated on the plant’s traditional uses, their pharmacological activities and their antidiabetic effects. It seems that many vegetable oils are really interesting and can be used in the improvement of human health, particularly, to prevent or to treat diabetes mellitus complications.

BACKGROUND:

Diabetes in humans induces chronic complications such as cardiovascular damage, cataracts and retinopathy, nephropathy and polyneuropathy. The most common animal model of humandiabetes is streptozotocin (STZ)-induced diabetes in the rat. The present study investigated the effects ofNigella sativa hydroalcholic extract on glucose concentrations in streptozotocin (STZ) diabetic rats.

METHODS:

In this study Twenty-five Wister-Albino rats (aged 8-9 weeks and weighing 200-250 g) were tested. Rats were divided into five experimental groups (control, untreated STZ-diabetic (60 mg/kg B.W., IP), treated STZ-diabetic with hydroalcholic extract of Nigella Sativa (NS) (5 mg/kg B.W, IP), treated STZ-diabetic with hydroalcholic extract of NS (10 mg/kg B.W., IP) and treated STZ-diabetic with hydroalcholic extract of NS (20 mg/kg B.W., IP and 32 days were evaluated to assess its effect on fasting blood glucose (FBG), and in different groups fasting blood glucose (FBG) and body weight (BW) were measured in the particular days (1, 16 and 32). At the end of the study, the animals were fasted overnight, anaesthetized with an intraperitoneal injection of sodium pentobarbital (60 mg/kg), and sacrificed for obtaining tissues samples (liver, pancreases). The number of islets and cells were counted and the islet diameters were determined by calibrated micrometer. The glycogen content in the liver was examined by Periodic Acid-Schiff (PAS) staining.

RESULTS:

Treatment with NS (5 mg/kg b.w.) markedly increased BW gain and the FBG level was significantly (p<0.001) reduced when compared to the control. Histopathological examination showed that the NS (5 mg/kg b.w.) partially recovered hepatic glycogen content and protected the great deal of the pancreatic islet cells. The number of islets, cells and islets diameter were found statistically significant when compared to the control (p<0.01, p<0.05).

CONCLUSIONS:

Higher doses of NS did not exhibit any therapeutic effect. These results showed that hydroalcholic extract of NS at low doses has hypoglycemic effect and ameliorative effect on regeneration of pancreatic islets and may be used as a therapeutic agent in the management of diabetes mellitus. The hypoglycemic effect observed could be due to amelioration of β-cell, thus leading to increased insulin levels. Consequently, N. sativa may prove clinically useful in the treatment of diabetics and in the protection of β-cells against streptozotocin.

Despite the enormous achievements in conventional medicine, herbal-based medicines are still a common practice for the treatment of diabetes. Trigonella foenum-graecum, Atriplex halimus, Olea europaea, Urtica dioica, Allium sativum, Allium cepa, Nigella sativa, and Cinnamomum cassia are strongly recommended in the Greco-Arab and Islamic medicine for the treatment and prevention of diabetes. Cytotoxicity (MTT and LDH assays) of the plant extracts was assessed using cells from the liver hepatocellular carcinoma cell line (HepG2) and cells from the rat L6 muscle cell line. The effects of the plant extracts (50% ethanol in water) on glucose transporter-4 (GLUT4) translocation to the plasma membrane was tested in an ELISA test on L6-GLUT4myc cells. Results obtained indicate that Cinnamomon cassia is cytotoxic at concentrations higher than 100”‰ μ g/mL, whereas all other tested extracts exhibited cytotoxic effects at concentrations higher than 500”‰ μ g/mL. Exposing L6-GLUT4myc muscle cell to extracts from Trigonella foenum-graecum, Urtica dioica, Atriplex halimus, and Cinnamomum verum led to a significant gain in GLUT4 on their plasma membranes at noncytotoxic concentrations as measured with MTT assay and the LDH leakage assay. These findings indicate that the observed anti-diabetic properties of these plants are mediated, at least partially, through regulating GLUT4 translocation.

OBJECTIVE:

The aim of this study was to investigate the effect of Nigella sativa and thymoquinone (TQ) on oxidative stress, cyclooxygenase-2 (COX-2), and intracellular adhesion molecule-1 mRNA expression in the pancreas of streptozotocin (STZ)-induced diabetic rats as a model of type 1 diabetes.

METHODS:

Five experimental groups including control group, STZ-induced diabetic group, aqueous extract diabetic treated group, oil diabetic treated group, and TQ diabetic treated group were used to obtain the pancreatic tissue samples and serum for investigation.

RESULTS:

A significant increase in COX-2 mRNA expression was detected in STZ-induced diabetic group after 10 days of diabetes induction indicating an important role of the enzyme COX-2 in the inflammation accompanying STZ diabetes in contrast to that detected for intracellular adhesion molecule-1. Treatment of STZ diabetic rats with N. sativa aqueous extract and TQ significantly suppressed the expression of COX-2 enzyme in the pancreatic tissue. Nigella sativa and TQ treatment also suppressed pancreatic tissue lipid peroxidation malondialdehyde levels and increased the level of superoxide dismutase antioxidant enzyme correlated with the decrease in COX-2 mRNA expression.

CONCLUSIONS:

Results obtained in this study support a potential role for N. sativa and TQ in ameliorating inflammation during diabetes and preserving β cells.

The effects of a polyherbal compound, containing six plants (Allium sativum, Cinnamomum zeylanicum,Nigella sativa, Punica granatum, Salvia officinalis and Teucrium polium) were tested on biochemical parameters in streptozotocin-induced diabetic rats. Streptozotocin caused an approximately 3-fold increase in fasting blood sugar level after 2 days. The diabetic control rats showed further increase in blood glucose after 30 days (384 ± 25”‰mg/dl in day 30 versus 280 ± 12”‰mg/dl in day 2, P < 0.001). Administration of the compound blocked the increase of blood glucose (272 ± 7 and 269 ± 48”‰mg/dl at day 2 and day 30, respectively). Also, there was significant difference in the level of triglyceride (60 ± 9 versus 158 ± 37”‰mg/dl, P < 0.01), total cholesterol (55 ± 2 versus 97 ± 11”‰mg/dl, P < 0.01) and aspartate amino transferase activity (75 ± 12 versus 129 ± 18”‰U/L, P < 0.05) between treated rats and diabetic control group. In conclusion, the MSEC inhibited the progression of hyperglycemia and decreased serum lipids and hepatic enzyme activity in diabetic rats. Therefore, it has the potential to be used as a natural product for the management of diabetes.

BACKGROUND AND AIM:

The atherogenic pattern of dyslipidemia associated with type 2 diabetes mellitus(DM) has been increasingly discussed. We have recently reported a hypoglycemic effect of Nigella sativa (NS) seeds in patients with type 2 DM. In this study we sought to assess the impact of NS seeds on lipid profile in type 2 diabetic patients.

PATIENTS AND METHOD:

A total of 94 patients with type 2 DM were recruited and divided into 3 dose groups. Capsules containing NS were administered orally in a dose of 1, 2, and 3 g/day for 12 weeks. All patients were subjected to measurement of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) before treatment and 4, 8, and 12 weeks thereafter.

RESULTS:

Patients receiving 1 g/day NS seeds for 12 weeks (group 1) showed nonsignificant changes in all the parameters except for a significant increase in HDL-c after 4 weeks of treatment. However, patients ingested 2 g/day NS displayed a significant decline in TC, TG, and LDL-c, and a significant elevation in HDL-c/LDL-c, compared with their baseline data and to group 1 patients. Increasing NS dose to 3 g/day failed to show any increase in the hypolipdemic effect produced by the 2 g/day dose.

CONCLUSION:

NS supplementation at a dose of 2 g/day for 12 weeks may improve the dyslipidemia associated with type 2 diabetic patients. Therefore, NS is a potential protective natural agent against atherosclerosis and cardiovascular complications in these patients.

Nigella sativa seeds (NS) has been used traditionally for various illnesses. The most abundant and active component of NS is thymoquinone (TQ). Animal studies have shown that NS and TQ may be used for the treatment of diabetes-induced osteoporosis and for the promotion of fracture healing. The mechanism involved is unclear, but it was postulated that the antioxidative, and anti-inflammatory activities may play some roles in the treatment of osteoporosis as this bone disease has been linked to oxidative stress and inflammation. This paper highlights studies on the antiosteoporotic effects of NS and TQ, the mechanisms behind these effects and their safety profiles. NS and TQ were shown to inhibit inflammatory cytokines such as interleukin-1 and 6 and the transcription factor, nuclear factor κB. NS and TQ were found to be safe at the current dosage for supplementation in human with precautions in children and pregnant women. Both NS and TQ have shown potential as antiosteoporotic agent but more animal and clinical studies are required to further assess their antiosteoporotic efficacies.