Effect of N. sativa oil on impaired glucose tolerance and insulin insensitivity induced by high-fat-diet and turpentine-induced trauma

The Efficacy of Nigella sativa L. and Curcumin Nanomicelle Alone or Together on Lipid Profile, Glycemic Control Indices, and Serum 17-Β Estradiol in Postmenopausal Women

Introduction

Menopause is a condition for metabolic disorders. This study aimed to evaluate the effect of Nigella sativa (NS), curcumin nanomicelle (CN), lipid profile, glycemic status and 17-β estradiol (ES) levels in postmenopausal women.

Methods

Triple-blind randomized clinical trial was conducted on 120 postmenopausal women. Participants were randomly assigned to four groups: 1) NS capsule 1000 mg and CN placebo, 2) 80 mg CN capsule and NS placebo, 3) both NS and CN capsules and 4) NS and CN placebo. Participants received a single dose daily for 6 months. The serum lipid profile, glycemic control biomarkers, and ES were measured pre-and post-intervention using biochemical methods.

Results

Total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, fasting blood sugar (FBS), fasting insulin (FI), insulin resistance (IR), and ES showed significant improvement in NS group. CN significantly reduced TC, FI, and IR, and significantly increased ES. The combination of NS-CN significantly decreased TC, LDL, FI, and IR, and increased HDL and ES. The comparison of the studied with the placebo groups showed that these changes were significant in glycemic indices and NS significantly increased estrogen.

Conclusion

NS, CN and NS-CN improved lipid profiles, blood sugar, and hormone levels. However, this improvement was significant in glycemic indices and estrogen levels compared to the placebo group. No superiority of combined NS-CN over NS or CN was found in this trial.

NEPHROPROTECTIVE AND DIURETIC EFFECT OF NIGELLA SATIVA L SEEDS OIL ON LITHIASIC WISTAR RATS

Background and objective:

The purpose of the current investigation was to study the influences, preventive and diuretic, of Nigella sativa L. seeds oil (NSSO) on calcium oxalate (CaOx) urolithiasis induced in Wistar male rats.

Methodology:

Seeds of Nigella sativa L. (N.S) were analysed for the evaluation of the concentration of oxalate and calcium. Nigella sativa L. seeds oil is obtained by hydrodistillation and HPTLC densitometric method was adopted to determine the amount of thymoquinone (TQ) present.

Thirty male Wistar rats were divided into 5 groups (N=6). Group I, negative control, drank tap water. The other groups were II Positive control, III, IV and V received a treatment model inducing calcium oxalate urolithiasis for 28 days, using an aqueous solution involve 0.75% (EG) ethylene glycol and 1.0 % (AC) chloride ammonium. Rats in group III received in addition, 750 mg/kg Cystone from the beginning to the end of calculi induction experimentation.

However, rats in Groups IV and V received (NSSO) at 5 ml/kg b.w by gavage on days 1^st to 28^th and 15^th to 28^th days, respectively. On days 0, 7, 14, 21 and 28, body weights were measured and the 24-hour urine samples were accumulated and analysed for biochemical elements. On the 28^th day, blood samples were collected for the estimation of serum parameters including creatinine, BUN and uric acid.

All animals were sacrificed at the end of the experiment and the kidneys were detached for histopathological examination.

Results:

Administration of (NSSO) at 5 ml/kg body weight/dose/day for 28 days exerts a protective effect by reducing significantly (p <0.01) urinary and serum rates of calcium, phosphate and oxalate. This preventive diet could increase the volume of urine excreted.

Conclusion:

The nephroprotectrice and diuretic activity demonstrated by Nigella sativa L. gives a scientific basis that approves their traditional use like a remedy against urolithiasis.

List of Abbreviations:NSSO: Nigella sativa L. Seeds oil ; CaOx: Calcium Oxalate; N.S: Nigella sativa L.; HPTLC: High performance thin layer chromatography; TQ: Thymoquinone; N: Number; EG: Ethylene Glycol; AC: Chloride Ammonium BUN: Blood Urea Nitrogen; LD₅₀: Lethal Dose 50; b.w: body weight; H & E: Haematoxyline and Eosin; HPLC-UV:;Caph: calcium phosphate; FR: glomerular filtration rate

Effects of Nigella sativa supplementation on blood parameters and anthropometric indices in adults: A systematic review on clinical trials

BACKGROUND

Nigella sativa (N. sativa) has been used in traditional medicine and several studies have been performed in the last decades to reveal the effects of it on different medical disorders such as diabetes, dyslipidemia, hypertension, and obesity. We evaluated the effects of N. sativa supplementation on lipid profiles, glycemic control, blood pressure (BP), and some anthropometric indices in humans.

MATERIALS AND METHODS

A search on published studies was done by using databases including PubMed, Google Scholar, Thomas Reuters Web of Science, and Cochrane. Medical subject headings (MeSH) terms searched included "N. sativa," "Black seed," "Black cumin," "kalonji," and "Triglycerides," "Cholesterol," "Lipoproteins," "LDL," "Lipoproteins," "HDL," "Blood glucose," "Hemoglobin A," "Glycosylated," "Blood pressure," "Body mass index," "Waist circumference". Initially 515 articles were extracted. Four hundred ninety-two papers that were unrelated, reviews, animal studies, and combined and duplicated studies were excluded, 23 articles were eligible for this review.

RESULTS

After analyzing 23 articles including 1531 participants, these results were achieved: In 4 trials, N. sativa reduced BP, but in 5 trials it could not. Fasting blood sugar (FBS) was reduced significantly in 13 studies. In addition, N. sativa reduced levels of glycosylated hemoglobin (HbA1c). Although weight and waist circumference (WC) in 2 articles were reduced significantly, in 6 articles they were not. Fluctuation in lipid profile in the articles was very controversial, being significant in many of them but not in others.

CONCLUSION

Our systematic review revealed that N. sativa supplementation might be effective in glycemic control in humans.

Protective Effects of Nigella sativa on Metabolic Syndrome in Menopausal Women

PURPOSE

This study was conducted in menopausal women to determine the metabolic impact of Nigella sativa.

METHODS

Thirty subjects who were menopausal women within the age limit of 45-60 were participated in this study and randomly allotted into two experimental groups. The treatment group was orally administered with N. sativa seeds powder in the form of capsules at a dose of 1g per day after breakfast for period of two months and compared to control group given placebo. Anthropometric and biochemical parameters were measured at baseline, 1st month, 2nd month and a month after treatment completed to determine their body weight, serum lipid profile and fasting blood glucose (FBG).

RESULTS

The treatment group showed slight reduction with no significant difference in body weight changes of the respondents. However, significant (p<0.05) improvement was observed in total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and blood glucose (p<0.05).

CONCLUSION

These results suggested that treatment with N. sativa exert a protective effect by improving lipid profile and blood glucose which are in higher risk to be elevated during menopausal period.

Protective and antidiabetic effects of extract from Nigella sativa on blood glucose concentrations against streptozotocin (STZ)-induced diabetic in rats: an experimental study with histopathological evaluation

Background

Diabetes in humans induces chronic complications such as cardiovascular damage, cataracts and retinopathy, nephropathy and polyneuropathy. The most common animal model of human diabetes is streptozotocin (STZ)-induced diabetes in the rat. The present study investigated the effects of Nigella 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.

Virtual slide

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1845133011104231

Ghrelin inhibits insulin release by regulating the expression of inwardly rectifying potassium channel 6.2 in islets

INTRODUCTION

The objective is to investigate the influence of ghrelin administration on both the insulin secretion and the expression of ATP-sensitive K(+) channels in islet.

METHODS

Ghrelin and [D-Lys] growth hormone releasing peptide-6 were administered via intraperitoneal injection in Wistar rats at the doses 10 and 10 μmol/kg/d for 2 weeks, respectively. Then glucose tolerance tests were performed and plasma insulin concentrations were measured. Islets were isolated for insulin release experiments. Single β cells were isolated for electrophysiological experiments. Determination of the Kir6.2 and SUR1 mRNA and protein expression levels in islets was performed by polymerase chain reaction and western blotting.

RESULTS

Intraperitoneal administration of exogenous ghrelin significantly (P < 0.05) increased blood glucose concentrations, attenuated insulin responses during glucose tolerance tests, reduced insulin release from the isolated islets induced by 11.1 and 16.7 mmol/L glucose, hyperpolarized the resting membrane potential and increased the Kir6.2 mRNA and protein expression levels. In contrast, counteraction of ghrelin by intraperitoneal injection of [D-Lys(3)] growth hormone releasing peptide-6 significantly (P < 0.05) attenuated the aforementioned changes. SUR1 expression levels were not altered in this study.

CONCLUSIONS

Ghrelin via pancreatic growth hormone secretagogue receptor up-regulates the Kir6.2 expression in islet by hyperpolarizing the resting membrane potential which results in the inhibition of insulin release.