Therapeutic effects of thymoquinone in a model of neuropathic pain

Topical Nigella sativa L. product: a new candidate for the management of diabetic peripheral neuropathy

BACKGROUND

Diabetic neuropathy is one of the most common complications of diabetes. The synthetic drugs available in the market have side effects and limitations for diabetic patients, the vast majority of whom are in the upper age group. In this regard, based on Persian medicinal sources, Nigella sativa (N. sativa) has proved to have beneficial effects on neuropathic pain and neurological disorders. In this study, the effect of N. sativa is investigated topically in patients with diabetic neuropathy.

METHODS

This study was performed as a double-blind clinical trial on 120 neuropathic patients. The patients were divided into three groups. The first group received a topical N. sativa product as an ointment, the second group was given a topical placebo, and the third received 300 mg gabapentin capsules. The blindness was done in first and second groups. Diabetic neuropathy was assessed before the study using the Michigan Neuropathy Screening Instrument (MNSI). In addition, neuropathy symptoms were evaluated after the trial using the MNSI questionnaire.

RESULTS

The data were elicited from the patients' answers to a number of questions in the Michigan questionnaire. There were statistically significant differences between the group that received the topical N. sativa product and the other two groups in terms of legs and feet numbness (p value = 0.001), burning pain in feet or legs (p value = 0.001), muscle cramps in feet or legs (p value = 0.001), prickling fleeing in feet or legs (p value = 0.001), hurting of the skin when the bed covers touch it (p value = 0.005), aggravated symptoms at night (p value = 0.001) and hurting feelings in the legs when walking (p value = 0.032). However, the three studied groups were not statistically different in distinguishing hot water from cold water.

CONCLUSION

According to the results of this study, the topical use of N. sativa, compared to the current drugs, has acceptable improving effects on diabetic neuropathic patients.

From Plant to Chemistry: Sources of Active Opioid Antinociceptive Principles for Medicinal Chemistry and Drug Design

Pain continues to be an enormous global health challenge, with millions of new untreated or inadequately treated patients reported annually. With respect to current clinical applications, opioids remain the mainstay for the treatment of pain, although they are often associated with serious side effects. To optimize their tolerability profiles, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery, and they hold potential for pain management. Traditional medicine has had a long history in clinical practice due to the fact that nature provides a rich source of active principles. For instance, opium had been used for pain management until the 19th century when its individual components, such as morphine, were purified and identified. In this review article, we conducted a literature survey aimed at identifying natural products interacting either directly with opioid receptors or indirectly through other mechanisms controlling opioid receptor signaling, whose structures could be interesting from a drug design perspective.

Herbal Honey Preparations of Curcuma Xanthorriza and Black Cumin Protect against Carcinogenesis through Antioxidant and Immunomodulatory Activities in Sprague Dawley (SD) Rats Induced with Dimethylbenz(a)anthracene

BACKGROUND

Traditionally, Curcuma xanthorriza (CX), black cumin seed (BC), and honey have been used by the Indonesian people as medicinal ingredients to treat various health symptoms. CX extracts and BC have been proven in the laboratory as chemopreventive agents, antioxidants, and immunomodulators. In this study, we developed CX extract, BC oil, and honey into herbal honey preparations (CXBCH) and hypothesized that the preparations show chemopreventive activity. The purpose of the study was to determine the CXBCH potential as chemopreventive, antioxidant, and immunomodulatory.

METHOD

In this experimental laboratory research, antioxidant, immunomodulatory, and cytotoxic activities were tested on human mammary cancer cell lines (T47D cells) while the chemopreventive activity of the CXBCH preparations on Sprague Dawley (SD) rats induced with dimethylbenzene(a)anthracene (DMBA).

RESULTS

CXBCH preparations demonstrated immunomodulatory, antioxidant, and cytotoxic activities in T47D, Hela, and HTB-183 cells and in DMBA-induced SD rats, as the preparations inhibited tumor nodule formation, increased the number of CD4, CD8 and CD4CD25 cells, and glutathione-S-transferase (GST) activity, and decreased serum NO levels.

CONCLUSIONS

CXBCH preparations display chemopreventive, antioxidant, and immunomodulatory properties.

The Ameliorative Effect of Thymoquinone on Vincristine-Induced Peripheral Neuropathy in Mice by Modulating Cellular Oxidative Stress and Cytokine

Thymoquinone (TQ), an active constituent of Nigella sativa, has been reported to exert a broad spectrum of pharmacological effects, including neuroprotective, anticancer, anti-inflammatory, antidiabetic, antiepileptic, antioxidant, and other modulatory roles in inflammation in experimental studies. The present study aims to evaluate the potential effects of TQ on vincristine-induced neuropathy in mice, as well as the possible role of oxidative stress, and pro- and anti-inflammatory cytokine in neuropathy development. A Swiss strain of male albino mice were randomly divided into seven groups, comprising of five animals each. Vincristine sulfate (0.1 mg/kg, i.p.) was administered for 10 consecutive days for the induction of peripheral neuropathy. The animals received their respective treatment of TQ (2.5, 5, and 10 mg/kg, p.o.) and pregabalin (10 mg/kg, p.o.) concurrently with vincristine for 10 days followed by 4 days post treatment. The animals were assessed for pain and related behavior on day 7 and 14 using hot and cold plates, and a rotarod test. TQ preventive treatment attenuated vincristine induced neuropathy in a dose dependent manner evidenced as a significant (p < 0.001) increase in reaction time on the hot plate and the cold plate, and a fall off time on the rotarod test. Further, TQ preventive treatment resulted in a significant (p < 0.001) reduction in the number of flinches and duration of paw elevation in a formalin test. Preventative treatment with TQ abolished the vincristine-induced rise in malondialdehyde and glutathione depletion in sciatic nerve tissue, as well as the blood IL-6 levels. In conclusion, TQ at 2.5, 5, and 10 mg/kg dose produced significant attenuation of neuropathic pain induced by vincristine which may be due to its antinociceptive, antioxidant, and anti-proinflammatory activity.

Development of Stable Liposomal Drug Delivery System of Thymoquinone and Its In Vitro Anticancer Studies Using Breast Cancer and Cervical Cancer Cell Lines

Thymoquinone, a well-known phytoconstituent derived from the seeds of Nigella sativa, exhibits unique pharmacological activities However, despite the various medicinal properties of thymoquinone, its administration in vivo remains challenging due to poor aqueous solubility, bioavailability, and stability. Therefore, an advanced drugdelivery system is required to improve the therapeutic outcome of thymoquinone by enhancing its solubility and stability in biological systems. Therefore, this study is mainly focused on preparing thymoquinone-loaded liposomes to improve its physicochemical stability in gastric media and its performance in different cancer cell line studies. Liposomes were prepared using phospholipid extracted from egg yolk. The liposomal nano preparations were evaluated in terms of hydrodynamic diameter, zeta potential, microscopic analysis, and entrapment efficiency. Cell-viability measurements were conducted using breast and cervical cancer cell lines. Optimized liposomal preparation exhibited polygonal, globule-like shape with a hydrodynamic diameter of less than 260 nm, PDI of 0.6, and zeta potential values of -23.0 mV. Solid-state characterizations performed using DSC and XRPD showed that the freeze-dried liposomal preparations were amorphous in nature. Gastric pH stability data showed no physical changes (precipitation, degradation) or significant growth in the average size of blank and thymoquinone-loaded liposomes after 24 h. Cell line studies exhibited better performance for thymoquinone-loaded liposomal drug delivery system compared with the thymoquinone-only solution; this finding can play a critical role in improving breast and cervical cancer treatment management.

Box-Behnken Design (BBD) Application for Optimization of Chromatographic Conditions in RP-HPLC Method Development for the Estimation of Thymoquinone in Nigella sativa Seed Powder

Thymoquinone (THY) is a bioactive compound present in the seed powder of Nigella sativa (NS). This research aims to precisely and accurately estimate THY using high-performance liquid chromatography (HPLC) with a Quality by Design (QbD) application. Box-Behnken design (BBD) was employed to optimize the chromatographic conditions for HPLC method development, taking mobile phase flow rate, pH of the buffer, and λmax as independent variables and retention time and tailing factor as the measured responses. The mobile phase composition was methanol: acetonitrile: buffer (2.2 mM ammonium formate) at the ratio of 35:50:15 v/v/v on a Symmetry® C18 (5 μm, 3.9 × 150 mm) column. In isocratic mode, it had a flow rate 0.9 mL min−1 and eluted analyte was detected at 249 nm. Validation parameters followed the International Council for Harmonization (ICH) guidelines for the new HPLC method. The method was linear over the range 6.25–100 µg mL−1 with a coefficient of determination (r2) of 0.9957. The limit of detection (LOD) and limit of quantification (LOQ) were 2.05 and 6.25 µg mL−1, respectively. The %RSD of system suitability for retention time was 1.42% and for the tailing factor it was 0.695%. In addition, the developed method was precise, accurate, and robust according to ICH criteria. The developed HPLC method is simple, accurate, quick, and robust, and it could be used for the routine analysis of THY in different kinds of formulations.

Therapeutic perspectives of the black cumin component thymoquinone: A review

The dietary phytochemical thymoquinone (TQ), belonging to the family of quinones, mainly obtained from the black and angular seeds of Nigella sativa, is one of the promising monoterpenoid hydrocarbons, which has been receiving massive attention for its therapeutic potential and pharmacological properties. It plays an important role as a chemopreventive and therapeutic agent in the treatment of various diseases and illnesses. The aim of this review is to present a summary of the most recent literature pertaining to the use of TQ for the prevention and treatment of various diseases along with possible mechanisms of action, and the potential use of this natural product as a complementary or alternative medicine. Research findings indicated that TQ exhibits numerous pharmacological activities including antioxidant, anti-inflammatory, cardioprotective, hepatoprotective, antidiabetic, neuroprotective, and anticancer, among others. Conclusions of this review on the therapeutic aspects of TQ highlight the medicinal and folk values of this compound against various diseases and ailments. In short, TQ could be a novel drug in clinical trials, as we hope.

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.

Stereological and histopathological evaluation of the effect of Thymoquinone on peridural fibrosis following laminectomy in rats

Background/aim

This study’s aim was to investigate the effects of thymoquinone, which is the essential bioactive component of the volatile oil of Nigella sativa on the peridural fibrosis in rats following laminectomy.

Materials and methods

Twenty female Wistar Albino rats were used in our study. The rats were randomly divided into 2 groups: Sham and Surgery + Thymoquinone. Both groups underwent laminectomy at L1 under general anesthesia. The Sham group was not subjected to any drug application. The 2nd group was treated with intraperitoneal 10-mg/kg thymoquinone once per day for a period of 28 days, following the same surgical procedure. All of the group specimens were sacrificed after 4 weeks, and the laminectomy area was examined in terms of new bone volume, capillary volume, and fibrosis volume using stereological approaches.

Results

Statistically significant differences were found between the Sham and Surgery + Thymoquinone groups in terms of new bone volume (P = 0.01), capillary volume (P = 0.01), and fibrosis volume (P < 0.001). It was noted that Thymoquinone caused a significant increase in new bone volume, vascular volume and, a significant decrease in fibrosis volume.

Conclusion

The results of our study indicate that thymoquinone is effective in decreasing peridural fibrosis when applied to a laminectomy model.

Thymoquinone reduces ischemia and reperfusion-induced intestinal injury in rats, through anti-oxidative and anti-inflammatory effects

OBJECTIVES

The aim of the present study was to investigate the effect of thymoquinone on ischemia/reperfusion (I/R) injury at 150 min or/and 24 h of reperfusion in male Wistar Rats.

MATERIAL AND METHODS

The therapeutic value of thymoquinone on cellular damage caused by reactive oxygene species or inflammatory processes during intestinal ischemia/reperfusion was investigated using pharmacological function studies on smooth muscle contractile responses of acetylcholine (Ach) and KCl, along with myeloperoxidase activity, malondialdehyhde, glutathione and cytokine levels such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β in serum and ileum tissue of rats. Thymoquinone was administered at a dose of 50 mg/kg orally for three times: 30 min, 24 h and 48 h prior to the surgical procedure. Soon after reperfusion timing (150 min or 24 h), the contractility traces to KCl and acetylcholine of the ileum smooth muscle were recorded through isolated organ bath.

RESULTS

Pretreatment with thymoquinone reversed the disrupted contractility of the ileum smooth muscle at the 24 h reperfusion. Increased malondialdehyde and depleted glutathione levels and high myeloperoxidase activity determined in the ileum I/R tissue returned to reasonable amounts by pretreatment of Thymoquinone, which attenuated malondialdehyde quantity, restored glutathione level and inhibited myeloperoxidase activity. In addition, both serum and tissue TNF-α and IL-1β activities were modulated by thymoquinone at 24 h of intestinal I/R.

CONCLUSION

The results indicate that thymoquinone may have therapeutic value due to its immunomodulating, radical scavenging and/or antioxidant effects in intestinal I/R injury including oxidant damage mechanisms.

Role of Oxidative Stress, MAPKinase and Apoptosis Pathways in the Protective Effects of Thymoquinone Against Acrylamide-Induced Central Nervous System Toxicity in Rat

The present study evaluated biochemical endpoints characterizing acrylamide (ACR) neurotoxicity in the cortex of rats, following the possible neuroprotective activity of thymoquinone (TQ), an active constituent of Nigella sativa. ACR (50 mg/kg, intraperitoneal [i.p.]) concurrently with TQ (2.5, 5 and 10 mg/kg, i.p.) for 11 days were administered to rats. As positive control, vitamin E was used. After 11 days of injections, narrow beam test (NBT) was performed. The levels of reduced glutathione (GSH) and malondialdehyde (MDA) were measured and Western blotting was done for mitogen-activated protein kinases (MAPKinases) and apoptosis pathways proteins in the rats' cortex. Additionally, Evans blue assay was done to evaluate the integrity of blood brain barrier (BBB). Administration of ACR significantly induced gait abnormalities. A significant decrease and increase in the levels of GSH and MDA was observed in the cortex of ACR-treated rats, respectively. The elevation in the levels of caspases 3 and 9, glial fibrillary acidic protein (GFAP) content, and Bax/Bcl-2, P-P38/P38 and P-JNK/JNK ratios accompanied by reduction in myelin basic protein (MBP) content and P-ERK/ERK ratio were noticed in the ACR group. TQ (5 mg/kg) improved gait abnormalities, and restored these changes. ACR affected the integrity of BBB while TQ was able to maintain the integrity of this barrier. TQ reversed the alterations in the protein contents of MAP kinase and apoptosis signaling pathways as well as MBP and GFAP contents, induced by ACR. It protected against ACR-mediated neurotoxicity, partly through its antioxidant and antiapoptotic properties.

Nigella sativa fixed oil as alternative treatment in management of pain in arthritis rheumatoid

BACKGROUND

N. sativa seeds is the source of fixed oil, which contain fatty acids and thymoquinone. N. sativa fixed oil topically or orally is used traditionally for management of pain in back, joints, musculoskeletal organs and arthritis rheumatoid.

PURPOSE

The aim of this review article was to evaluate the potential effects of N. sativa fixed oil in pain and inflammation, especially in arthritis rheumatoid.

METHODS

All information was extracted from accessible and inaccessible sources (books, electronic sources, thesis and etc.).

RESULTS

The results of our investigation showed N. sativa fixed oil, especially thymoquinone content had valuable anti-inflammatory and analgesic effects via different pathways. The efficacy of thymoquinone as potential treatment was confirmed in different animal model of arthritis and the clinical studies confirmed the oral (n = 4) and topical use (n = 1) of N. sativa fixed oil without adverse effects in patients suffering from arthritis rheumatoid.

CONCLUSION

The larger multicenter clinical trials for comparing the efficacy of topical, oral administrations and current treatment may help to understand better the efficacy of valuable fixed oil.

Neuropharmacological Potential and Delivery Prospects of Thymoquinone for Neurological Disorders

Thymoquinone (TQ) is an active ingredient isolated from Nigella sativa and has various pharmacological activities, such as protection against oxidative stress, inflammation, and infections. In addition, it might be a potential neuropharmacological agent because it exhibits versatile potential for attenuating neurological impairments. It features greater beneficial effects in toxin-induced neuroinflammation and neurotoxicity. In various models of neurological disorders, it demonstrates emergent functions, including safeguarding various neurodegenerative diseases and other neurological diseases, such as stroke, schizophrenia, and epilepsy. TQ also has potential effects in trauma mediating and chemical-, radiation-, and drug-induced central nervous system injuries. Considering the pharmacokinetic limitations, research has concentrated on different TQ novel formulations and delivery systems. Here, we visualize the neuropharmacological potential, challenges, and delivery prospects of TQ, specifically focusing on neurological disorders along with its chemistry, pharmacokinetics, and toxicity.

Effect of ursolic acid in attenuating chronic constriction injury-induced neuropathic pain in rats

Ursolic acid (UA; 3b-hydroxy-12-urs-12-en-28-oic acid), a natural pentacyclic triterpenoid carboxylic acid, has been known to possess potent anti-inflammatory, antioxidant, and antinociceptive effects in various animal models. Therefore, this study was designed to investigate the antihyperalgesic, anti-inflammatory, and antioxidant effects of UA at 5, 10, and 20 mg/kg of doses via per os (p.o.) route for 14 days in chronic constriction injury (CCI)-induced neuropathic pain in rats. Pain behavior in rats was evaluated before and after UA administration via mechanical and heat hyperalgesia. CCI caused significant increase in levels of pro-inflammatory cytokines and oxido-nitrosative stress. In addition, significant increase in myeloperoxidase, malondialdehyde, protein carbonyl, nitric oxide (NO), and total oxidant status (TOS) levels in sciatic nerve and spinal cord concomitant with mechanical and heat hyperalgesia is also noted for CCI-induced neuropathic pain. Administration of UA significantly reduced the increased levels of pro-inflammatory cytokines and TOS. Further, reduced glutathione is also restored by UA. UA also showed in vitro NO and superoxide radical scavenging activity. UA has a potential in attenuating neuropathic pain behavior in CCI model which may possibly be attributed to its anti-inflammatory and antioxidant properties.

Protective effect of thymoquinone against lead-induced hepatic toxicity in rats

Lead (Pb) intoxication is a worldwide health problem which frequently affects the liver. This study was carried out to investigate the potential protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb-induced liver damage. Adult male rats were randomized into four groups: Control group received no treatment, Pb group was exposed to 2000 ppm Pb acetate in drinking water, Pb-TQ group was cotreated with Pb plus TQ (5 mg/kg/day, per orally), and TQ group receiving only TQ. All treatments were applied for 5 weeks. Results indicated that Pb exposure increased hepatic Pb content, damaged hepatic histological structure (necrotic foci, hepatic strands disorganization, hypertrophied hepatocytes, cytoplasmic vacuolization, cytoplasmic loss, chromatin condensation, mononuclear cell infiltration, congestion, centrilobular swelling), and changed liver function investigated by plasma biochemical parameters (AST, ALT, ALP, γ-GT, LDH). Pb treatment also decreased total antioxidant status level and increased lipid peroxidation in the liver. Supplementation with TQ remarkably improved the Pb-induced adverse effects without significantly reducing the metal accumulation in the liver. In conclusion, our results indicate, for the first time, a protective effect of TQ against Pb-induced hepatotoxicity and suggest that this component might be clinically useful in Pb intoxication.