Emerging clinical and therapeutic applications of Nigella sativa in gastroenterology

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.

Evaluation of differential white blood cell count and cheek pouch epithelium in 7,12-dimethylbenza[a]anthracene hamster carcinogenesis model, managed with three phytochemicals

Objectives: Nigella sativa (NS), thymoquinone (TQ), and epigallocatechin-3-gallate (EGCG) are phytochemicals that might have antioxidant protective potentials on the hamster cheek pouch epithelium (HCPE). We aimed at evaluating and comparing the potential therapeutic outcomes of these 3 phytochemicals by analysis of peripheral white blood cells (WBCs) counts. Materials and Methods: NS whole oil, TQ and EGCG were administered before, with or after 7,12-dimethylbenza[a]anthracene (DMBA) painting the hamster left cheek pouch. Before sacrificing each animal, 2 ml of blood was withdrawn into a fine heparin-containing tube to estimate the total WBCs, lymphocytes, MID cells, and granulocytes counts by an automatic count system. All cheek pouches were surgically excised and examined with light microscope. Results: Severe epithelial dysplasia was evident after 6 weeks of DMBA administration, and when NS was given for 2 weeks followed by DMBA for 6 weeks. When NS or EGCG were given for 2 weeks then continued with DMBA for 6 weeks, mild dysplasia was seen. When DMBA was given for 6 weeks followed by NS or TQ for 6 weeks, mild dysplasia was noted. Administration of DMBA for 6 weeks resulted in significant reduction in total WBCs and lymphocytes counts compared to healthy controls. Administration of NS or TQ for 2 weeks resulted in significant elevation in lymphocytes count compared to healthy controls. Significant elevation in total WBCS and lymphocytes counts was noted when EGCG was given for 2 weeks and continued with DMBA for other 6 weeks. Similar results were noted when DMBA was given for 6 weeks followed by TQ for 6 weeks when compared to NS, DMBA or healthy controls. Discussion: The three phytochemicals showed different levels of protection against DMBA carcinogenic activity, more specifically, TQ and NS had higher therapeutic potential and might be used for treatment and/or preventive management of oral cancer in the future. Conclusion: However, further investigations are required to address the mechanism of action and feasibility of clinical application of each phytochemical.

Effect of Allium sativum and Nigella sativa on alleviating aluminum toxicity state in the albino rats

The study objective was to evaluate Allium sativum's potential and Nigella Sativa's combination's potential to reduce aluminum toxicity and return to the normal state. In the present study, a hundred albino rats were randomly divided into five equal groups. The first group was used as a control group; the other four groups were exposed to aluminum 1,600 ppm. The second exposed to aluminum only; the third and fourth groups were treated with Allium sativum 5% and Nigella sativa 5%, respectively, while the fifth group was treated with a mix of Allium sativum 2.5% and Nigella sativa 2.5% for 8th weeks. After 8 weeks, the aluminum administration was stopped, and the second group was divided into three groups. The groups were treated with Allium sativum 5% and Nigella sativa 5%, and a mix of Allium sativum 2.5% and Nigella sativa 2.5%, respectively. The first group was the control group (continued from the first experiment). Garlic and Nigella sativa were crushed and added to feed while receiving aluminum chloride daily at a dose of 1.6 ml/l was added to the drinking water. Histopathological changes in the liver, kidney, and testes were investigated after 8 and 16 weeks, and blood samples were collected after 4, 8, and 16 weeks for biochemical blood parameters. The results showed that the histopathological examination of the liver, kidney, and testes showed signs of congestion in blood vessels after aluminum exposure. Meanwhile, the treatment with Allium sativum or Nigella sativum or the mixture between them had positive effects on evading the harmful effects of aluminum in the liver, Kidney, and testes tissues. In addition, there were protective effects for Allium sativum and Nigella sativa against aluminum on serum creatinine, urea, ALT, and AST concentrations. The present study concluded that supplementation with Allium sativum or Nigella sativa or their combination could reduce aluminum toxicity and return the liver, kidney, and testes to normal.

Therapeutic Potential and Pharmaceutical Development of Thymoquinone: A Multitargeted Molecule of Natural Origin

Thymoquinone, a monoterpene molecule is chemically known as 2-methyl-5-isopropyl-1, 4-benzoquinone. It is abundantly present in seeds of Nigella sativa L. that is popularly known as black cumin or black seed and belongs to the family Ranunculaceae. A large number of studies have revealed that thymoquinone is the major active constituent in N. sativa oil this constituent is responsible for the majority of the pharmacological properties. The beneficial organoprotective activities of thymoquinone in experimental animal models of different human diseases are attributed to the potent anti-oxidant and anti-inflammatory properties. Thymoquinone has also been shown to alter numerous molecular and signaling pathways in many inflammatory and degenerative diseases including cancer. Thymoquinone has been reported to possess potent lipophilicity and limited bioavailability and exhibits light and heat sensitivity. Altogether, these physiochemical properties encumber the successful formulation for the delivery of drug in oral dosages form and restrict the pharmaceutical development. In recent past, many efforts were undertaken to improve the bioavailability for clinical usage by manipulating the physiochemical parameters. The present review aimed to provide insights regarding the physicochemical characteristics, pharmacokinetics and the methods to promote pharmaceutical development and endorse the clinical usage of TQ in future by overcoming the associated physiochemical obstacles. It also enumerates briefly the pharmacological and molecular targets of thymoquinone as well as the pharmacological properties in various diseases and the underlying molecular mechanism. Though, a convincing number of experimental studies are available but human studies are not available with thymoquinone despite of the long history of use of black cumin in different diseases. Thus, the clinical studies including pharmacokinetic studies and regulatory toxicity studies are required to encourage the clinical development of thymoquinone.

Neuropharmacological effects of Nigella sativa

Nigella sativa (NS) (Ranunculaceae family) is generally utilized as a therapeutic plant all over the world. The seeds of the plant have a long history of use in different frameworks of medicines and food. In Islamic literature, it is considered as one of the greatest forms of therapeutics. It has been widely used to treat nervous system diseases such as memory impairment, epilepsy, neurotoxicity, pain, etc. Additionally, this is uncovered that the majority of therapeutic properties of this plant are due to the presence of thymoquinone (TQ) which is a major bioactive component of the essential oil. Pharmacological studies have been done to evaluate the effects of NS on the central nervous system (CNS). The present review is an effort to provide a detailed scientific literature survey about pharmacological activities of the plant on nervous system. Our literature review showed that NS and its components can be considered as promising agents in the treatment of nervous system disorders.

A review on therapeutic potential of Nigella sativa: A miracle herb

Nigella sativa (N. sativa) (Family Ranunculaceae) is a widely used medicinal plant throughout the world. It is very popular in various traditional systems of medicine like Unani and Tibb, Ayurveda and Siddha. Seeds and oil have a long history of folklore usage in various systems of medicines and food. The seeds of N. sativa have been widely used in the treatment of different diseases and ailments. In Islamic literature, it is considered as one of the greatest forms of healing medicine. It has been recommended for using on regular basis in Tibb-e-Nabwi (Prophetic Medicine). It has been widely used as antihypertensive, liver tonics, diuretics, digestive, anti-diarrheal, appetite stimulant, analgesics, anti-bacterial and in skin disorders. Extensive studies on N. sativa have been carried out by various researchers and a wide spectrum of its pharmacological actions have been explored which may include antidiabetic, anticancer, immunomodulator, analgesic, antimicrobial, anti-inflammatory, spasmolytic, bronchodilator, hepato-protective, renal protective, gastro-protective, antioxidant properties, etc. Due to its miraculous power of healing, N. sativa has got the place among the top ranked evidence based herbal medicines. This is also revealed that most of the therapeutic properties of this plant are due to the presence of thymoquinone which is major bioactive component of the essential oil. The present review is an effort to provide a detailed survey of the literature on scientific researches of pharmacognostical characteristics, chemical composition and pharmacological activities of the seeds of this plant.

Canola oil influence on azoxymethane-induced colon carcinogenesis, hypertriglyceridemia and hyperglycemia in Kunming mice

Azoxymethane (AOM) is a potent genotoxic carcinogen which specifically induces colon cancer. Hyperlipidemia and diabetes have several influences on colon cancer development, with genetic and environmental exposure aspects. Here, we investigated plasma lipid and glucose concentrations in Kunming mice randomized into four groups; control (no AOM or oil exposure), AOM control, AOM + pork oil, and AOM + canola oil. Aberrant crypt foci (ACF), plasma cholesterol, plasma triglyceride, plasma glucose and organ weight were examined 32 weeks after AOM injection. Results revealed that AOM exposure significantly increased ACF number, plasma triglyceride and glucose level. Further, male mice displayed a much higher plasma triglyceride level than female mice in the AOM control group. Dietary fat significantly inhibited AOM-induced hypertriglyceridemia, and canola oil had stronger inhibitory effect than pork oil. AOM-induced hyperglycemia had no sex-difference and was not significantly modified by dietary fat. However, AOM itself not change plasma cholesterol level. AOM significantly increased liver and spleen weight in male mice, but decreased kidney weight in female mice. On the other hand, mice testis weight decreased when fed canola oil. AOM could induce colorectal carcinogenesis, hypertriglyceridemia and hyperglycemia in Kunming mice at the same time, with subsequent studies required to investigate their genome association.

The effect of Nigella sativa Linn. seed on memory, attention and cognition in healthy human volunteers

BACKGROUND

Experimental evidences have demonstrated that Nigella sativa Linn. seed (NS) has positive modulation effects on aged rats with memory impairments, prevents against hippocampal pyramidal cell loss and enhances consolidation of recall capability of stored information and spatial memory in rats. NS has neuroprotective, nephroprotective, lung protective, cardioprotective, hepatoprotective activities as established by previous studies on animals. Several clinical trials with NS on human have also demonstrated beneficial effect.

AIM OF THE STUDY

The present study was designed to investigate the effects of NS on memory, attention and cognition in healthy elderly volunteers. Furthermore, safety profile of NS was assessed during the nine-week study period.

METHODS

Forty elderly volunteers were recruited and divided randomly into group A and group B--each consisting of 20 volunteers. The treatment procedure for group A was 500 mg NS capsule twice daily for nine weeks and Group B received placebo instead of NS in the similar manner. All the volunteers were assessed for neuropsychological state and safety profile twice before treatment and after nine weeks. The neuropsychological tests were logical memory test, digit span test, Rey-Osterrieth complex figure test, letter cancellation test, trail making test and stroop test. Safety profile was assessed by measuring biochemical markers of Cardiac (total cholesterol, triglycerides and high density lipoprotein cholesterol, very low density lipoprotein, low density lipoprotein cholesterol, creatine kinase-MB); Liver (aspartate aminotransferase, alanin aminotransferase, alkaline phosphatase, total protein, albumin, bilirubin) and Kidney (creatinine and blood urea nitrogen) through using commercial kits.

RESULTS

There was significant difference (p<0.05) in the score of logical memory test-I and II, total score of digit span, 30 min delayed-recall, percent score in Rey-Osterrieth complex figure test, time taken to complete letter cancellation test, time taken in trail making test-A and test-B, score in part C of stroop test due to ingestion of NS for nine weeks. There were not statistically significant changes (p>0.05) in any of the biochemical markers of cardiac, liver, kidney function during this nine-week study period.

CONCLUSIONS

The current study demonstrates the role of NS in enhancing memory, attention and cognition. Therefore, whether NS could be considered as potential food supplement for preventing or slow progressing of Alzheimer disease needs further investigations. However, study with Alzheimer's patients with large population size for longer period of time is recommended before using NS daily and extensive phytochemical investigations are recommended for novel drug discovery from NS for treating cognitive disorders.

Maternal supplementation of diabetic mice with thymoquinone protects their offspring from abnormal obesity and diabetes by modulating their lipid profile and free radical production and restoring lymphocyte proliferation via PI3K/AKT signaling

Background

Epidemiological studies have shown that the offspring of mothers who experience diabetes mellitus during pregnancy are seven times more likely to develop health complications than the offspring of mothers who do not suffer from diabetes during pregnancy. The present study was designed to investigate whether supplementation of streptozotocin (STZ)-induced diabetic pregnant mice with thymoquinone (TQ) during pregnancy and lactation improves the risk of developing diabetic complications acquired by their offspring.

Methods

Three groups of pregnant female mice were used: non-diabetic control dams (CD), diabetic dams (DD), and diabetic dams supplemented with TQ (DD + TQ) during pregnancy and lactation (n = 10 female mice in each group).

Results

Our data demonstrated a marked decrease in the number of neonates born to DD, and these neonates showed a marked increase in their mean body weight (macrosomic pups) compared to those born to CD and DD + TQ. The induction of diabetes during pregnancy and lactation resulted in macrosomic pups with several postpartum complications, such as a marked increase in their levels of blood glucose, free radicals, plasma pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), and lipids, and a tendency toward abnormal obesity compared to the offspring of CD. By contrast, macrosomic offspring born to DD exhibited a marked reduction in plasma cytokine levels (IL-2, -4 and -7), an obvious reduction in the number of circulating lymphocytes, decreased proliferation of superantigen (SEB)-stimulated lymphocytes and aberrant AKT phosphorylation. Interestingly, the supplementation of DD with TQ during pregnancy and lactation had an obvious and significant effect on the number and mean body weight of neonates. Furthermore, TQ significantly restored the levels of blood glucose, insulin, free radicals, plasma cytokines, and lipids as well as lymphocyte proliferation in the offspring.

Conclusions

Our data suggest that the nutritional supplementation of DD with the natural antioxidant TQ during pregnancy and lactation protects their offspring from developing diabetic complications and preserves an efficient lymphocyte immune response later in life.