Immunomodulatory and cytotoxic effects of Nigella sativa and thymoquinone on rat splenocytes

The molecular basis of the immunomodulatory effects of natural products: A comprehensive review

BACKGROUND

Natural products (NPs) have long been recognized for their potential to modulate the immune system, offering a natural and holistic approach to enhancing immune function. In recent years, the immunomodulation effects of various natural products have attained significant attention.

PURPOSE

This article provides an overview of the role of natural products in immunomodulation, exploring their mechanisms of action, common types of NPs with immunomodulation properties, clinical applications, as well as considerations for their safety and efficacy.

METHODS

Extensive research has been conducted to compile important discoveries on the immunomodulatory properties of NPs through thorough searches of multiple databases such as PubMed, Science Direct, and Scopus up until January 2024.

RESULTS

By decreasing the levels of Th2 cytokines and pro-inflammatory cytokines, the results suggested that NPs have the ability to modulate the immune system. Therefore, NPs alleviate inflammation in various disorders such as asthma and cancer. Furthermore, the observed increase in CD4 cells and IFN-ɣ/IL4 levels, along with an increased IFN-c/IL4 ratio, indicates a stimulatory effect of NPs on Th1 activity in various inflammatory conditions. Therefore, NPs regulate the immune system by inhibiting T-cells and decreasing the growth of young B-cell lymphoma cells.

CONCLUSION

Reviewing studies indicated that NPs have the potential to serve as immunomodulatory candidates for treating disorders characterized by immune dysregulation. However, additional experimental and clinical studies are necessary before these agents can be implemented in clinical settings.

Systematic Review of Chemical Compounds with Immunomodulatory Action Isolated from African Medicinal Plants

A robust, well-functioning immune system is the cornerstone of good health. Various factors may influence the immune system's effectiveness, potentially leading to immune system failure. This review aims to provide an overview of the structure and action of immunomodulators isolated from African medicinal plants. The research was conducted according to PRISMA guidelines. Full-text access research articles published in English up to December 2023, including plant characteristics, isolated phytochemicals, and immuno-modulatory activities, were screened. The chemical structures of the isolated compounds were generated using ChemDraw® (version 12.0.1076), and convergent and distinctive signaling pathways were highlighted. These phytochemicals with demonstrated immunostimulatory activity include alkaloids (berberine, piperine, magnoflorine), polysaccharides (pectin, glucan, acemannan, CALB-4, GMP90-1), glycosides (syringin, cordifolioside, tinocordiside, aucubin), phenolic compounds (ferulic acid, vanillic acid, eupalitin), flavonoids (curcumin, centaurein, kaempferin, luteolin, guajaverin, etc.), terpenoids (oleanolic acid, ursolic acid, betulinic acid, boswellic acids, corosolic acid, nimbidin, andrographolides). These discussed compounds exert their effects through various mechanisms, targeting the modulation of MAPKs, PI3K-Akt, and NF-kB. These mechanisms can support the traditional use of medicinal plants to treat immune-related diseases. The outcomes of this overview are to provoke structural action optimization, to orient research on particular natural chemicals for managing inflammatory, infectious diseases and cancers, or to boost vaccine immunogenicity.

The Immunomodulatory Effect of Nigella sativa

BACKGROUND

For thousands of years till nowadays, Nigella sativa (NS) has served as a common spice and food preservative. Its seed extracts, seed oil, and essential oil in traditional medicine have been used to remedy many ailments such as headaches, fever, gastric complaints, and even rheumatism. In addition, the antibacterial, virucidal, fungicidal, and antiparasitic properties of NS are well known. However, studies on the possible immunomodulatory effects of black cumin are relatively scarce. This article discusses in vitro and in vivo research supporting the immunomodulatory role of NS.

METHODS

The review is based on articles, books, and conference papers printed until September 2022, found in the Web of Science, PubMed, Wiley Online Library, and Google Scholar databases.

RESULTS

Experimental findings were reported concerning the ability of NS to modulate inflammation and immune responses or cytotoxic activity.

CONCLUSIONS

All results suggest that NS can potentially be employed in developing effective therapeutic agents for regulating immune reactions.

Comparative study on the impacts of visnagin and its methoxy derivative khellin on human lymphocyte proliferation and Th1/Th2 balance

BACKGROUND

Visnagin is a phenolic and natural compound in turmeric and fenugreek, and its anti-inflammatory effect has been indicated. Therefore, this study aimed to investigate and compare the anti-inflammatory properties of visnagin and its methoxy derivative khellin on human lymphocytes.

METHODS

Human lymphocytes were treated with khellin, visnagin (10, 30, and 100 µM), and dexamethasone (0.1 mM) in the presence of phytohemagglutinin (PHA). The levels of cell proliferation, nitric oxide (NO), glutathione (GSH), malondialdehyde (MDA), and MDA/GSH ratio were measured using biochemistry methods. Furthermore, the mRNA levels of interferon-γ (IFN-γ), interleukin (IL)-4, and IL-10 were assessed using real-time PCR, while IFN-γ/IL-4(Th₁/Th₂), IFN-γ/IL-10(Th₁/T_reg), and IL-4/IL-10(Th₂/T_reg) ratios were made by dividing their exact values.

RESULTS

In the PHA-stimulated group, GSH and IFN-γ/IL-4 levels were markedly diminished, but other variables were significantly elevated compared to the control group. Khellin and visnagin significantly declined the levels of cell proliferation, MDA, MDA/GSH ratio, and NO production. Khellin and visnagin concentration-dependently diminished IFN-γ and IL-4 levels and increased IL-10 levels compared to the PHA-stimulated group. Two higher concentrations of khellin and visnagin (30 and 100 μM) considerably diminished the IFN-γ, IFN-γ/IL-10, and IL-4/IL-10 values compared to the PHA-stimulated group. However, 100 µM of khellin and visnagin significantly increased GSH level compared to the PHA-stimulated group.

CONCLUSIONS

In PHA-stimulated lymphocytes, representing Th₂ dominant allergic diseases, khellin and visnagin provides more specific anti-oxidant, anti-inflammatory, and immunomodulatory functions than dexamethasone. In addition, the effects of khellin were more prominent than visnagin.

Crocetin regulates Th1/Th2 and Th17/Treg balances, nitric oxide production, and nuclear localization of NF-κB in Th2-provoked and normal situations in human-isolated lymphocytes

Crocetin is a natural carotenoid dicarboxylic acid derived from Crocus sativus. It has been utilized as natural biomedicine with healing effects. The immunoregulatory and anti-inflammatory properties may cause the biological activities of crocetin. Nevertheless, it is not still clear how this compound acts and causes an immune-modulatory impact on human lymphocytes. The effects of three concentrations (5, 10, and 20 μM) of crocetin or dexamethasone (0.1 mM) were assessed on gene expression and secretion of cytokines, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) level, and nitric oxide (NO) production in phytohaemagglutinin (PHA)-stimulated and non-stimulated lymphocytes. By incubation with PHA, gene expression and cytokine concentration comprising interferon (IFN)-γ, interleukin (IL)-17A, IL-10, and IL-4 were increased, along with NF-κB concentration and NO production (all, p < 0.001). In comparison with the controls, an alteration occurred in the T-helper (Th)2/Th1 and Th17/Treg balance in the stimulated lymphocyte toward a Th2 and Th17 response. In stimulated cells, crocetin and dexamethasone decreased pro-inflammatory significantly and increased anti-inflammatory cytokines and related gene expression, respectively. Moreover, Th17/Treg and Th1/Th2 balance was changed toward Treg and Th1 significantly reducing NF-κB and NO levels (p < 0.05 to p < 0.001). Promoting effects were represented by crocetin on T-cell subsets to Treg and Th1. Hence, it can have therapeutic value for treating predominant diseases of Th2 or Th17 cells.

The effect of Zataria multiflora on respiratory allergic and immunologic disorders, experimental and clinical evidence: A comprehensive review

Zataria multiflora (Z. multiflora) is used in traditional and modern medicine for therapeutic objectives especially in respiratory disorders. Therefore, updated experimental and clinical studies on the effects of Z. multiflora on respiratory, allergic, and immunologic disorders are reviewed. Various electronic search engines including PubMed, Science Direct, Scopus, and Google Scholar were searched using appropriate keywords until the end of November 2021. Books, thesis-hard copies of some articles were also included. The effects of Z. multiflora on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection, and lung cancer were shown. Extracts of Z. multiflora showed the relaxant effect with various mechanisms. The preventive effects of Z. multiflora were also demonstrated by mechanisms such as antioxidant, immunomodulatory, and antiinflammatory properties in the experimental animal models of different respiratory diseases. Carvacrol and thymol are probably responsible for the therapeutic effect of plant among 56 constituents of Z. multiflora. In addition, bronchodilatory and preventive effects of the plant and its constituents on asthma, COPD, lung disorders due to noxious agents and allergic and immunologic disorders were shown in the clinical studies. Therefore Z. multiflora and its constituents may be considered as a preventive and/or relieving therapy in various respiratory diseases.

Hematological and biochemical investigations on the effect of curcumin and Thymoquinone in male mice exposed to Thioacetamide

Currently, living organisms are increasingly exposed to many toxic chemicals in the environment. These substances pose a threat to human life, other living organisms and ecosystem. In fact, there is an increasing requirement to search for safe therapeutic sources today. Medicinal plants and natural products have become of great importance globally because of their therapeutic potential and medicinal properties, as well as their availability and the absence of harmful side effects for most of them. The present study was designed to explore the potential protective effect of curcumin (CUR) and thymoquinone (TQ) in male rats exposed to thioacetamide (TAA). The experimental mice were divided into eight groups. Group 1 was served as control. Group 2 was exposed to 50 mg/ kg body weight of TAA. Group 3 was exposed to CUR and TAA. Mice of group 4 were treated with TQ and TAA. Mice of group 5 were exposed to CUR plus TQ and TAA. Group 6 was supplemented with CUR. Group 7 was subjected to TQ. Mice of group 8 were treated with CUR and TQ. Hematological and biochemical alterations were evaluated after one month. Significant increases of white blood corpuscles (WBC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TB), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) values were observed in group 2, while the values of red blood corpuscles (RBC), hemoglobin (Hb(, hematocrit (Hct), glutathione (GSH) and superoxide dismutase (SOD) were statistically decreased. Treatment with CUR, TQ and their combination inhibited the hematological and biochemical alterations induced by TAA toxicity. Moreover, the most protective effect was observed in mice treated with CUR plus TQ. These new results suggested that the protective effect of CUR and TQ attributed to their antioxidant properties.

Possible therapeutic effects of Nigella sativa and its thymoquinone on COVID-19

CONTEXT

COVID-19 is a novel coronavirus that causes a severe infection in the respiratory system. Nigella sativa L. (Ranunculaceae) is an annual flowering plant used traditionally as a natural food supplement and multipurpose medicinal agent.

OBJECTIVE

The possible beneficial effects of N. sativa, and its constituent, thymoquinone (TQ) on COVID-19 were reviewed.

METHODS

The key words including, COVID-19, N. sativa, thymoquinone, antiviral effects, anti-inflammatory and immunomodulatory effects in different databases such as Web of Science (ISI), PubMed, Scopus, and Google Scholar were searched from 1990 up to February 2021.

RESULTS

The current literature review showed that N. sativa and TQ reduced the level of pro-inflammatory mediators including, IL-2, IL-4, IL-6, and IL-12, while enhancing IFN-γ. Nigella sativa and TQ increased the serum levels of IgG1 and IgG2a, and improved pulmonary function tests in restrictive respiratory disorders.

DISCUSSION AND CONCLUSIONS

These preliminary data of molecular docking, animal, and clinical studies propose N. sativa and TQ might have beneficial effects on the treatment or control of COVID-19 due to antiviral, anti-inflammatory and immunomodulatory properties as well as bronchodilatory effects. The efficacy of N. sativa and TQ on infected patients with COVID-19 in randomize clinical trials will be suggested.

Possible treatment with medicinal herbs and their ingredients of lung disorders induced by sulfur mustard exposures: a review

Chemical warfare (CW) agents are toxic synthetic chemicals that affect human's health, and sulfur mustard (SM) is a well-known chemical weapon that caused deaths of victims. The lung is the main target of SM exposure, and there are no definitive therapeutic modalities for lung injury induced by this agent. The possible therapeutic effects of medicinal plants and their active ingredients on lung injury induced by SM were reviewed in this article until the end of June 2021. Medicinal plants including Crocus sativus, Curcuma longa, Thymus vulgaris, Nigella sativa, and Zataria multiflora and also natural compounds showed therapeutic potential in improving of various features of lung injury induced by SM and other related chemical agents. Several studies showed therapeutic effects of some medicinal plants and natural products on lung inflammation, oxidative stress, and immune responses in experimental studies in SM-induced lung injury. In addition, clinical studies also showed the effect of medicinal plants and natural compounds on respiratory symptoms, pulmonary function tests (PFTs), and inflammatory markers. The therapeutic effects of medicinal plants and natural products on lung disorder induced by SM and related chemical agents were shown through amelioration of various features of lung injury.

Effect of Thymoquinone on Th1 and Th2 Balance in Rats Infected with Mycobacterium tuberculosis

Thymoquinone is an active compound in Nigella sativa which has potential immunomodulatory effect. Mycobacterium tuberculosis could alter the Th1 and Th2 balance by stimulating phagocyte IL-1β production, and subsequent Th2 differentiation. We aim to evaluate the effect of thymoquinone (TQ) in restore the Th1 and Th2 balance in Mycobacterium tuberculosis infection. Four groups of rats were infected with virulent Mycobacterium tuberculosis strain H37Rv. Thymoquinone at different doses was given to three groups, and one group left without treatment. Additional one group was either infected or treated with TQ. We measure IL-1β, IL-4 and IFN-γ levels using ELISA 14 days after TQ treatment. We found there were increased IL-1β, IL-4 and IFN-γ level after Mycobacterium tuberculosis infection, but we observe no significant effect of TQ treatment to Th1 and Th2 balance.  We conclude that TQ could not restore Th1 and Th2 balance in rats infected with Mycobacterium tuberculosis.

Novel Insight into Potential Leishmanicidal Activities of Transdermal Patches of Nigella Sativa: Formulation Development, Physical Characterizations, and In vitro/In vivo Assays

Cutaneous Leishmaniasis (CL) is the most common type of Leishmaniasis, which annually affects 1.5 million people worldwide. About 90% of cases are reported from countries such as Iran, Afghanistan, Pakistan, Iraq, and Saudi Arabia. The purpose of the present study was to fabricate transdermal patches of Nigella sativa (NS), characterize, and to check its in vitro/in vivo anti-Lieshmanial activity. Hydroalcoholic extract was analyzed for preliminary phytochemicals. Five formulations of transdermal patches (NS1, NS2, NS3, NS4, and NS5) were prepared by solvent evaporation method. The optimized formulation NS5 was characterized for Fourier transform-infrared spectroscopy (FTIR), smoothness, brittleness, clarity, thickness, folding endurance, uniformity of weight, percent moisture content, in vitro drug release, release kinetics, ex vivo drug permeation, and in vitro anti-Lieshmanial activity. In vivo anti-Lieshmanial activity was assessed in 30 patients (n = 30) suffering from CL. The FTIR studies showed no incompatibility among the active extract and polymers. In vitro anti-Lieshmanial assay was 194.6% ± 1.88% as compared with standard drug (p > 0.05) and in vivo anti-Lieshmanial activity was 75%. The drug release after 24 h was 87.0% ± 0.94% in NS5, which showed non-Fickian diffusion mechanism while drug permeation across rabbit skin after 24 h was up to 80.0% ± 0.91%. The results concluded that problems related to the parenteral medications used for Lieshmanial treatment can be managed by applying extract of NS seeds in the form of transdermal patch.

A qualitative and quantitative comparison of Crocus sativus and Nigella sativa immunomodulatory effects

The present article reviews and compares the immunomodulatory activities of Crocus sativus (C. sativus) and Nigella sativa (N. sativa) and their main bioactive compounds. Immunomodulatory effects of these plants, especially with respect to Th1 and Th2 cytokines, are discussed based on relevant articles, books, and conference papers published in English until the end of April 2020, that were retrieved from Web of Science, PubMed, Scopus and Google Scholar databases. C. sativus and its constituents increase immunoglobulin (Ig-)G, interleukin 2 (IL)-2, interferon gamma (IFN-γ), and IFN-γ/IL-4 ratio, but decreased IgM, IL-10 and IL-4 secretion. N. sativa extract and thymoquinone reduce the levels of IL-2, -4, -10, and -12, while enhance IFN-γ and serum IgG1 and 2a. The reviewed articles indicate that C. sativus and N. sativa and their constituents could be potentially considered promising treatments for disorders associated with immune-dysregulation such as asthma and cancer.

Global survey of medicinal plants during lactation and postpartum recovery: Evolutionary perspectives and contemporary health implications

ETHNOPHARMACOLOGICAL RELEVANCE

Cross-cultural comparison of plants used during lactation and the postpartum period offers insight into a largely overlooked area of ethnopharmacological research. Potential roles of phytochemicals in emerging models of interaction among immunity, inflammation, microbiome and nervous system effects on perinatal development have relevance for the life-long health of individuals and of populations in both traditional and contemporary contexts.

AIM OF THE STUDY

Delineate and interpret patterns of traditional and contemporary global use of medicinal plants ingested by mothers during the postpartum period relative to phytochemical activity on immune development and gastrointestinal microbiome of breastfed infants, and on maternal health.

MATERIALS AND METHODS

Published reviews and surveys on galactagogues and postpartum recovery practices plus ethnobotanical studies from around the world were used to identify and rank plants, and ascertain regional use patterns. Scientific literature for 20 most-cited plants based on frequency of publication was assessed for antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antidepressant, analgesic, galactagogic and safety properties.

RESULTS

From compilation of 4418 use reports related to 1948 species, 105 plant taxa were recorded ≥7 times, with the most frequently cited species, Foeniculum vulgare, Trigonella foenum-graecum, Pimpinella anisum, Euphorbia hirta and Asparagus racemosus, 81, 64, 42, 40 and 38 times, respectively. Species and use vary globally, illustrated by the pattern of aromatic plants of culinary importance versus latex-producing plants utilized in North Africa/Middle East and Sub-Saharan Africa with opposing predominance. For 18/20 of the plants a risk/benefit perspective supports assessment that positive immunomodulation and related potential exceed any safety concerns. Published evidence does not support a lactation-enhancing effect for nearly all the most-cited plants while antidepressant data for the majority of plants are predominately limited to animal studies.

CONCLUSIONS

Within a biocultural context traditional postpartum plant use serves adaptive functions for the mother-infant dyad and contributes phytochemicals absent in most contemporary diets and patterns of ingestion, with potential impacts on allergic, inflammatory and other conditions. Polyphenolics and other phytochemicals are widely immunologically active, present in breast milk and predominately non-toxic. Systematic analysis of phytochemicals in human milk, infant lumen and plasma, and immunomodulatory studies that differentiate maternal ingestion during lactation from pregnancy, are needed. Potential herb-drug interaction and other adverse effects should remain central to obstetric advising, but unless a plant is specifically shown as harmful, considering potential contributions to health of individuals and populations, blanket advisories against postpartum herbal use during lactation appear empirically unwarranted.

The effects of Nigella sativa on respiratory, allergic and immunologic disorders, evidence from experimental and clinical studies, a comprehensive and updated review

Nigella sativa (N. sativa) seed had been used traditionally due to several pharmacological effects. The updated experimental and clinical effects of N. sativa and its constituents on respiratory, allergic and immunologic disorders are provided in this comprehensive review article. Various databases including PubMed, Science Direct and Scopus were used. The preventive effects of N. sativa on pulmonary diseases were mainly due to its constituents such as thymoquinone, thymol, carvacrol and alpha-hederin. Extracts and constituents of N. sativa showed the relaxant effect, with possible mechanisms indicating its bronchodilatory effect in obstructive pulmonary diseases. In experimental animal models of different respiratory diseases, the preventive effect of various extracts and constituents of N. sativa was demonstrated by mechanisms such as antioxidant, immunomodulatory and antiinflammatory effects. Bronchodilatory and preventive effects of the plant and its components on asthma, COPD and lung disorders due to exposure to noxious agents as well as on allergic and immunologic disorders were also shown in the clinical studies. Various extracts and constituents of N. sativa showed pharmacological and therapeutic effects on respiratory, allergic and immunologic disorders indicating possible remedy effect of that the plant and its effective substances in treating respiratory, allergic and immunologic diseases.

Chemopreventive and Anticancer Effects of Thymoquinone: Cellular and Molecular Targets

Thymoquinone (TQ) is a bioactive component derived from the seeds of Nigella sativa that are commonly as black cumin. Evidences indicate that the medicinal properties of TQ have been recognized for more than 2000 years. TQ has been shown to possess potent chemopreventive properties that include anti-inflammatory and anti-neoplastic activities. Recent studies have unraveled the multiple mechanisms through which TQ exerts its chemopreventive and anticancer activity in different cancer cells in a contextual manner. The present review aims to provide a brief compendium on the molecular mechanisms through which TQ inhibits signaling pathways underlying cancer genesis, progression, and metastasis.

Treadmill exercise ameliorates memory deficits and hippocampal inflammation in ovalbumin-sensitized juvenile rats

The behavioral changes, including spatial learning and memory impairment as well as depressive- and anxiety-like behaviors in an animal model of asthma were demonstrated previously. On the other hand, there is increasing evidence that the anti-inflammatory actions of exercise are related to their neuroprotective properties against different insults in the brain. This study was aimed to explore the effects of moderate treadmill exercise on cognitive deficits and possible anti-inflammatory mechanisms in ovalbumin (OVA)-sensitized rats. The exercise groups were trained to run on the treadmill 30 min/day with an intensity of 12 m/min, 5 days/week for 4 weeks. Animals in the OVA groups were sensitized by two intraperitoneal (i.p.) injections of OVA (10 μg/injection) and challenged with OVA by inhalation during the treadmill running exercise period. Passive avoidance (PA) memory, levels of interleukin (IL)-10 and tumor necrosis factor (TNF)-α in the hippocampus, total and differential white blood cell (WBC) count in the blood as well as pathological changes of the lung were then evaluated. OVA-sensitization was resulted in cognitive deficits in the PA task, along with increased total and differential WBC in blood and TNF-α in the hippocampus. However, exercise ameliorated these changes and increased the IL-10 level in the hippocampus, suggesting that moderate treadmill exercise can improve memory impairment in OVA-sensitized rats due to its anti-inflammatory properties.

Nigella sativa (black seed) safety: an overview

Nigella sativa (commonly known as black seed or black cumin), from the family Ranunculaceae, is a plant that grows in countries bordering the Mediterranean Sea. This narrative review discusses the toxicological profile reported by short- to long-term studies that examined different extracts and oils of N. sativa seeds. Scientific databases including Web of Science, PubMed, Scopus, and Google Scholar were searched using appropriate keywords. LD50 for administered N. sativa seed fixed oil varied from 28.8 mL/kg to 3,371 mg/kg in mice, while 21 g/kg of aqueous, methanol, and chloroform extracts of N. sativa did not lead to any mortality. Subacute toxicity evaluations indicated that aqueous, methanol, and chloroform extracts of N. sativa at doses as high as 6 g/kg do not produce toxicity. Investigation of chronic toxicity found that 2 mL/kg of N. sativa fixed oil is slightly toxic. Cytotoxicity studies indicated that N. sativa chloroform and petroleum ether extracts are more cytotoxic than its other extracts. Although studies that assessed N. sativa toxicity generally introduced it as a safe medicinal herb, to draw a more definitive conclusion on its safety, more detailed studies must be conducted.

The protective effect of Nigella sativa extract on lung inflammation and oxidative stress induced by lipopolysaccharide in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Oxidative stress during inflammation can increase inflammation and damage tissue. Nigella sativa L. (NS) showed many pharmacological properties including antioxidant and anti-inflammatory activities.

AIM OF THE STUDY

In this study, the preventive effect of NS on lung inflammation and oxidative stress induced by lipopolysaccharide (LPS) in the rats was investigated.

MATERIALS AND METHODS

Male rats were assigned to: Control, LPS (1 mg/kg, i.p.), LPS + NS (100, 200, 400 mg/kg, i.p.), (10 per group). Saline (1 ml/kg) was intra-peritoneal (i.p.) injected instead of LPS in the rats of the control group. LPS dissolved in saline and injected i.p. daily for 14 days. Treatment with NS extracts started two days before LPS administration and treatment continued during LPS administration. White blood cells (WBC), total and differential as well as oxidative stress index in bronchoalveolar fluid (BALF) and serum, TGF-β1, IFN-γ, PGE₂, and IL-4 levels in the BALF and lung histopathology were examined.

RESULTS

LPS administration increased total WBC, eosinophils, neutrophils, basophils, and monocytes counts as well as oxidative stress markers in the BALF and serum as well as TGF-β1, IFN-γ, PGE₂, IL-4 levels in the BALF and pathological changes of the lung tissue. All of these effects were reduced by NS extract treatment dose-dependently.

CONCLUSION

These results suggested the protective effects of NS extract on lung inflammation and oxidative stress as well as its effect on lung pathology induced by LPS dose-dependently.

The effect of chronic supplementation of Nigella sativa on splenocytes response in rats following treadmill exercise

Nigella sativa (N. sativa) was shown to recover fatigue and imbalanced immune system. Therefore, effect of chronic administration of N. sativa hydroethanolic extract on splenocytes response in sedentary and exercised animals, was evaluated. Male Wistar rats were randomly divided into non-treated (control sedentary (C), moderately trained (MT; Velocity 20 m/min, 30 min/day 8 weeks), and over-trained (OT; Velocity 25 m/min, 60 min/day 11 weeks)), and N. sativa-treated animals (Nisa, 200 mg/kg, orally) (control (Nisa-C), moderately trained (Nisa-MT) and over-trained (Nisa-OT)). Finally, cell viability and proliferation, as well as interleukin 4 (IL-4) and interferon-γ (IFN-γ) secretion in non-stimulated and concanavalin A (Con A)-stimulated splenocytes, were evaluated. In the absence of the mitogen, cell viability in Nisa-C and Nisa-OT, cell proliferation in Nisa-C and Nisa-MT, IFN-γ concentration in Nisa-MT and Nisa-OT and IFN-γ/IL-4 ratio in Nisa C, Nisa-MT and Nisa-OT were higher compared to non-treated groups; but, IL-4 level in Nisa-MT was lower than non-treated groups. In the presence of the mitogen, cell viability in Nisa-C and Nisa-OT, IL-4 concentration in Nisa-C and Nisa-OT groups, and IFN-γ concentration and IFN-γ/IL-4 ratio in Nisa-MT were higher, while IFN-γ/IL-4 ratio was lower in Nisa-C group compared to non-treated groups. Moreover, IFN-γ/IL-4 ratio in stimulated and non-stimulated splenocytes supernatant was higher in Nisa-MT compared to Nisa-C and Nisa-OT groups. N. sativa chronic administration may shift Th1/Th2 cytokines profile of splenocytes towards Th1, especially in over-trained and non-stimulated condition. Moderate exercise and N. sativa supplementation may improve disorders associated with elevated Th2 such as overtraining syndrome.

Thymoquinone Enhances the Effect of Gamma Knife in B16-F10 Melanoma Through Inhibition of Phosphorylated STAT3

BACKGROUND

Patients with brain metastasis from melanoma have a dismal prognosis with poor survival time. Gamma Knife (GK) is an effective treatment to control brain metastasis from melanoma. Thymoquinone (TQ) has emerged as a potential therapeutic option due to its antiproliferative effects on various cancers. The purpose of the study was to assess the effect of GK on B16-F10 melanoma cells in vitro and intracerebral melanoma in vivo, and its synergistic effect in combination with TQ.

METHODS

The effects of GK and combination treatment of GK and TQ were studied on B16-F10 melanoma cells by evaluating cytotoxicity with an adenosine triphosphate assay, apoptosis by acridine orange staining, and genotoxicity by comet assay. Western blot analysis was performed to investigate the expression of STAT3, p-STAT3 (Tyr705), JAK2, p-JAK2, caspase-3, Bax, Bcl-2, survivin, and β-actin. Expression of inflammatory cytokines was assessed by enzyme-linked immunosorbent assay. GK alone and in combination with TQ was assessed in an established intracerebral melanoma tumor in mice.

RESULTS

The effects of GK on cytotoxicity, genotoxicity, and apoptosis were enhanced by TQ in B16-F10 melanoma cells. GK induced apoptosis through inhibition of p-STAT3 expression, which in turn regulated pro- and antiapoptotic proteins such as caspase-3, Bax, Bcl-2, and survivin. Adding TQ to GK irradiation further enhanced this apoptotic effect of GK irradiation. GK was shown to reduce the levels of tumor-related inflammatory cytokines in B16-F10 melanoma cells. This effect was more pronounced when TQ was added to GK irradiation. GK with 15 Gy increased the survival of mice with intracerebral melanoma compared with untreated mice. However, despite the additive effect of TQ in addition to GK irradiation on B16-F10 melanoma cells in vitro, TQ did not add any significant survival benefit to GK treatment in mice with intracerebral melanoma.

CONCLUSIONS

Our findings suggest that TQ would be a potential therapeutic agent in addition to GK to enhance the antitumor effect of irradiation. Further studies are required to support our findings.

Thymoquinone increases the expression of neuroprotective proteins while decreasing the expression of pro-inflammatory cytokines and the gene expression NFκB pathway signaling targets in LPS/IFNγ -activated BV-2 microglia cells

Neuroinflammation and microglial activation are pathological markers of a number of central nervous system (CNS) diseases. Chronic activation of microglia induces the release of excessive amounts of reactive oxygen species (ROS) and pro-inflammatory cytokines. Additionally, chronic microglial activation has been implicated in several neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Thymoquinone (TQ) has been identified as one of the major active components of the natural product Nigella sativa seed oil. TQ has been shown to exhibit anti-inflammatory, anti-oxidative, and neuroprotective effects. In this study, lipopolysaccharide (LPS) and interferon gamma (IFNγ) activated BV-2 microglial cells were treated with TQ (12.5 μM for 24 h). We performed quantitative proteomic analysis using Orbitrap/Q-Exactive Proteomic LC-MS/MS (Liquid chromatography-mass spectrometry) to globally assess changes in protein expression between the treatment groups. Furthermore, we evaluated the ability of TQ to suppress the inflammatory response using ELISArray™ for Inflammatory Cytokines. We also assessed TQ's effect on the gene expression of NFκB signaling targets by profiling 84 key genes via real-time reverse transcription (RT2) PCR array. Our results indicated that TQ treatment of LPS/IFNγ-activated microglial cells significantly increased the expression of 4 antioxidant, neuroprotective proteins: glutaredoxin-3 (21 fold; p < 0.001), biliverdin reductase A (15 fold; p < 0.0001), 3-mercaptopyruvate sulfurtransferase (11 fold; p < 0.01), and mitochondrial lon protease (>8 fold; p < 0.001) compared to the untreated, activated cells. Furthermore, TQ treatment significantly (P < 0.0001) reduced the expression of inflammatory cytokines, IL-2 = 38%, IL-4 = 19%, IL-6 = 83%, IL-10 = 237%, and IL-17a = 29%, in the activated microglia compared to the untreated, activated which expression levels were significantly elevated compared to the control microglia: IL-2 = 127%, IL-4 = 151%, IL-6 = 670%, IL-10 = 133%, IL-17a = 127%. Upon assessing the gene expression of NFκB signaling targets, this study also demonstrated that TQ treatment of activated microglia resulted in >7 fold down-regulation of several NFκB signaling targets genes, including interleukin 6 (IL6), complement factor B (CFB), chemokine (CC motif) ligand 3 (CXCL3), chemokine (CC) motif ligand 5 (CCL5) compared to the untreated, activated microglia. This modulation in gene expression counteracts the >10-fold upregulation of these same genes observed in the activated microglia compared to the controls. Our results show that TQ treatment of LPS/IFNγ-activated BV-2 microglial cells induce a significant increase in expression of neuroprotective proteins, a significant decrease in expression inflammatory cytokines, and a decrease in the expression of signaling target genes of the NFκB pathway. Our findings are the first to show that TQ treatment increased the expression of these neuroprotective proteins (biliverdin reductase-A, 3-mercaptopyruvate sulfurtransferase, glutaredoxin-3, and mitochondrial lon protease) in the activated BV-2 microglial cells. Additionally, our results indicate that TQ treatment decreased the activation of the NFκB signaling pathway, which plays a key role in neuroinflammation. In conclusion, our results demonstrate that TQ treatment reduces the inflammatory response and modulates the expression of specific proteins and genes and hence potentially reduce neuroinflammation and neurodegeneration driven by microglial activation.

Auraptene regulates Th1/Th2/TReg balances, NF-κB nuclear localization and nitric oxide production in normal and Th2 provoked situations in human isolated lymphocytes

BACKGROUND

Auraptene as member of dietary coumarins, is found in citrus fruits. Former studies have demonstrated its anti-inflammatory and anti-cancer activity.

PURPOSE

The mechanism of action and immune-modulatory property of this compound on human lymphocytes are greatly unknown.

STUDY DESIGN/METHODS

The effect of three concentrations (10, 30 and 90 µM) of auraptene or dexamethasone (0.1 mM) were evaluated on percentage of cell proliferation and nitric oxide (NO) production as well as secretion and gene expression of cytokines, and NF-κB level in PHA-stimulated and non-stimulated lymphocytes.

RESULTS

In non-stimulated cells, all three concentrations of auraptene significantly increased the gene expression index of IL-10 (P < 0.05-0.001). The IFN-γ gene expression index, IFN-γ/IL-4 and IL-10/IL-4 gene expression ratio were significantly increased due to the high concentration (90 µM) of auraptene treatment compared to control group (P < 0.05-0.001). In PHA stimulation, all three concentrations of the extract significantly decreased proliferation, cytokines (IL-4, IL-10 and IFN-γ) and NF-κB level as well as NO production, but IFN-γ/IL-4 and IL-10/IL-4 ratio were significantly increased compared control group (P < 0.05-0.001). Gene expression of IL-10 and IL-4 was decreased but that of IFN-γ as well as FN-γ/IL-4 and IL-10/IL-4 ratio were significantly increased due to all three concentrations of auraptene.

CONCLUSION

The results showed promoting effects of auraptene on T cell subsets toward Th₁ (IFN-γ) and T_reg (IL-10), which suggest its therapeutic value for treatment of Th₂ cells predominant diseases including allergic disease such as asthma and atopic dermatitis as well as cancers.

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.

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.

Regressions of Breast Carcinoma Syngraft Following Treatment with Piperine in Combination with Thymoquinone

Thymoquinone (TQ) and piperine, the active ingredients in cumin (Nigella sativa) and black pepper (Piper longum), respectively, exhibit various bioactivities including anticancer effects. The aim of the present study is to investigate the antineoplastic activity of a combination of TQ and piperine against breast cancer implanted in mice. The antiproliferative effects of TQ, piperine, and a combination of both agents were tested against mouse epithelial breast cancer cell line (EMT6/P) using MTT assay. The isobolographic method was used to calculate the combination index (CI). Degree of angiogenesis inhibition was detected by measuring vascular endothelial growth factor (VEGF) levels in tissue culture for all treatments. EMT6/P cells were inoculated in Balb/C mice and the antitumor effect of TQ, piperine, and their combination was assessed. Changes in tumor size were calculated for all treatments. Tumor histology was examined using the hematoxylin/eosin staining protocol. Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) colorimetric assay and caspase-3 activity assays were used to detect apoptosis. Serum levels of interferon (INF)-γ, interleukin (IL)-4, IL-2, and IL-10 were measured using ELISA and treatment toxicity was evaluated by measuring serum levels of aspartate transaminase (AST), alanine transaminase (ALT), and creatinine. A clear synergistic antiproliferative interaction between TQ and piperine was observed with CI value of 0.788. The combination therapy resulted in significant reduction in tumor size with percentage cure of 60% and percentage death of 0%. High degrees of apoptosis and geographical necrosis were induced in tumors treated with the combination therapy. Combination therapy caused significant decrease in VEGF expression and increased serum INF-γ levels. Normal serum levels of AST, ALT, and creatinine were observed in tumor-bearing mice treated with the combination therapy. The combination of TQ and piperine acts synergistically to target breast cancer in vitro and in vivo. This novel combination exerts its effect by angiogenesis inhibition, apoptosis induction, and shifting the immune response toward T helper1 response. This combination therapy deserves further investigation (including measurement of hypoxia-inducible factor (HIF)1α to be used in clinical studies.

Thymoquinone as a Potential Adjuvant Therapy for Cancer Treatment: Evidence from Preclinical Studies

Thymoquinone (TQ), the main bioactive component of Nigella sativa, has been found to exhibit anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Moreover, TQ can specifically sensitize tumor cells toward conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells. In this review, we summarized the adjuvant potential of TQ as observed in various in vitro and in vivo animal models and discussed the pharmacological properties of TQ to rationalize its supplementary role in potentiating the efficacy of standard therapeutic modalities namely surgery, radiotherapy, chemotherapy, and immunotherapy. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical levels to delineate its implied utility as a novel complementary adjuvant therapy for cancer treatment.

Anti-Aging Effect of Nigella Sativa Fixed Oil on D-Galactose-Induced Aging in Mice

Objectives:

Aging is an unconscious and gradual process that can lead to changes in biological systems. Induction of oxidative stress and apoptosis, hepatotoxicity and neurotoxicity are involved in the aging process. Regarding the antioxidant property of black seed oil, the aim of this study was to evaluate the anti-aging effect of Nigella sativa (N. sativa) oil on d-galactose-induced aging in mice.

Methods:

For induction of aging, D-galactose (500 mg/kg, subcoutaneously SC) was administrated to male mice for 42 days. Animals were treated with D-galactose alone or with b lack seed oil (0.1, 0.2, 0.5 mL/kg, intraperitoneally (ip)). Additionally, vitamin E (200 mg/kg) was used as a positive control. At the end of treatment, the malondialdehyde (MDA) and the glutathione (GSH) contents in brain and liver tissues were measured. Also, enzymes in serum, including aspartate aminotransferase (AST) and alanine amino transferase (ALT), were determined. The levels of the proteins Bax, Bcl2, caspase-3 (pro and cleaved) in brain and liver tissues were evaluated.

Results:

Administration of D-galactose (500 mg/kg, SC) for 42 days increased serum levels of ALT and AST, as well as the MDA content, in brain and liver tissues, but decreased the GSH content. Additionally, the levels of apoptotic proteins, including Bax, procaspase-3 and caspase-3 cleaved, were markedly increased. N. sativa oil (0.1 and 0.2 mL/kg) diminished the levels of the biochemical markers ALT and AST. Administration of black seed oil (0.1, 0.2 and 0.5 mL/kg) reduced lipid peroxidation and at doses 0.1 and 0.2 mL/kg significantly recovered the GSH content. The oil decreased Bax/Bcl2 levels and at 0.1 mL/kg down-regulated the expressions of caspase-3 (pro and cleaved) proteins in brain and liver tissues.

Conclusion:

Through its antioxidant and anti-apoptosis properties, black seed oil exhibited an anti-aging effect in a model of aging induced with D-galactose.

The influence of hydro-ethanolic extract of Portulaca oleracea L. on Th1/Th2 balance in isolated human lymphocytes

ETHNOPHARMACOLOGICAL RELEVANCE

The anti-inflammatory and anti-oxidants activity of Portulaca oleracea L. (P. oleracea) were mentioned in traditional texts. In previous studies, different anti-inflammatory and anti-oxidant effects of P. oleracea were demonstrated. However, the mechanism of action and immunomodulatory property of this plant are greatly unknown. In the present study, the effect of the extract of this plant on IL-4, IL10, IFN-γ and T helper (h)1/Th2 balance in non-stimulated and stimulated human lymphocytes was examined.

MATERIALS AND METHODS

The effect of three concentrations (160, 40 and 10µg/ml) of P. oleracea or dexamethasone were evaluated on percentage of cell proliferation and nitric oxide (NO) production as well as secretion of cytokines (IL-4, IL10 and IFN-γ) in PHA-stimulated and non-stimulated lymphocytes, and compared to control and dexamethasone as positive control (n=15 for each group).

RESULTS

In stimulated cells, dexamethasone significantly inhibited the percentage of cell proliferation, NO production, and secretion of cytokines in comparison to control group (P<0.001 for all cases). The percentage of cell proliferation, NO production, and secretion of cytokines were significantly decreased while Th1/Th2 (IFN-γ/IL-4) and Treg/Th2 (IL-10/IL-4) balances significantly enhanced in treated groups with all three concentrations of extract compared to control group (P<0.001 for all cases). The effect of all concentrations of the extract on cell proliferation, NO production and secretion of cytokines as well as Treg/Th2 balance were significantly lower than dexamethasone (P<0.001 for all cases), but Th1/Th2 ratio obtained in the presence of only low extract concentration was lower than dexamethasone (P<0.01).

CONCLUSION

Different concentrations of extract promoted Th1/Th2 and Treg/Th2 balances which may suggest the therapeutic value of the plant in inflammatory disease associated with decreased Th1/Th2 balance such as asthma or cancers.

EFFECTS OF COMBRETUM HEREROENSE AND CANTHIUMMUNDIANUM water EXTRACTS ON PRODUCTION AND EXPRESSION OF INTERLEUKIN-4

BACKGROUND

Combretum hereroense and Canthium mundianum are two plants commonly used by traditional healers in the Northern region of Limpopo, South Africa for the treatment of diarrhea and inflammation. In the present study, the effects of their water extracts on the production and expression of interleukin-4 by peripheral blood mononuclear cells (PBMC'S) from HIV positive and negative individuals was evaluated.

MATERIALS AND METHODS

Blood samples were collected from both HIV positive and HIV negative volunteers and were used for the purification of Peripheral blood mononuclear cells (PBMC). The PBMCs were cultured together with the water extracts after activation with phytohemagglutinin (PHA) for three days. Solid-phase sandwich ELISA (MABTECH) kit was used to detect IL-4 on un-stimulated and stimulated PBMC'S with phytohemaglutinin (PHA) and plant extracts, followed by the isolation of RNA using RNAesy Qiagen mini kit from the cells. Reverse transcriptase real time PCR was used to evaluate IL-4 gene expression by the cells.

RESULTS

Combretum hereroense showed higher production of IL-4 at three different concentrations and a significant expression of mRNA with 4-fold amplification increase at 300μg/ml and 2-fold amplification increase at 20μg/ml. Canthium mundianum also showed increased production of IL-4 at 300μg/ml, but inhibited its production at 20μg/ml. Both extracts showed no expression at 50μg/ml. The response of the PBMCs from HIV negative individuals was more pronounced than that of HIV positive individuals who mostly increased production of IL4 at smaller concentrations unlike their HIV negative counterparts. Although in vitro studies do not necessarily predict in vivo outcomes, the plant extracts modulated the immune system by enhancing the production and expression of IL-4 in both HIV- and HIV+ individuals at different concentrations.

CONCLUSIONS

For the first time we have shown that the immunomodulatory effect of medicinal plants may depend on the clinical status of the individual. The present study revealed that the effect of the water extracts from the two plants on IL-4 expression and production is dependent on the microbiological state of the individual and is dose dependent. Further studies are needed to identify the active components in the extracts and also characterize the patients further for a better understanding of the mechanisms of action of these extracts.

Effect of thymoquinone on the healing of left colon anastomosis: an experimental study

Aim

To evaluate the effect of thymoquinone on the healing of experimental left colon anastomosis in rats.

Methods

Forty Wistar albino rats weighing 250–300 g were randomly divided into four groups (10 rats/group). Group 1 (control group) rats were not administered Thymoquinone (TQ) for 3 days after the operation. Group 2 was administered daily TQ for 3 days starting from the first day after the operation. Group 3 was not administered TQ for 7 days after the operation. Group 4 was administered daily TQ for 7 days starting from the first day after the operation. Thymoquinone was administered as a single dose oral gavage through a 4F feeding catheter per each day. The bursting strength of the anastomosis was measured on 3rd and 7th postoperative days (POD) and resection was performed. Subsequently, the hydroxyproline level in the resected tissue was measured and a histological evaluation was performed.

Results

The bursting pressures of the anastomoses were measured to be statistically significantly greater on 7th POD in TQ administered groups compared to those without TQ administration. Tissues were stained with Masson’s trichrome dye in order to evaluate the amount of fibrous tissue reaction for histopathological examination; there was no significant difference in the amount of fibrous tissue between groups 1 and 2, while a very marked increase in the fibrous tissue was detected in groups 3 and 4. Mean tissue hydroxyproline levels of the groups 3 and 4 on 7th POD were 1.30 and 2.72 μg/g-protein, respectively. The difference between the groups was statistically significant (p = 0.001).

Conclusions

TQ significantly increased the bursting pressure of the anastomosis, tissue hydroxyproline level, and fibrous tissue production.