Antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (black cumin) in mice infected with Plasmodium yoelli nigeriensis

Nigella sativa-Fortified Cookies Ameliorate Oxidative Stress, Inflammatory and Immune Dysfunction in Plasmodium berghei-Infected Murine Model

Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed (Nigella sativa) is a core dietary supplement and food additive in folklore. This study investigated the antioxidant, immunomodulatory, and anti-inflammatory effects of N. sativa cookies in Plasmodium berghei-infected mice. Aqueous extract of black seed was prepared, and the total phenol and flavonoid contents were determined. The mice were infected with standard inoculum of the strain NK65 P. berghei. The mice weight and behavioral changes were observed. The mice were fed with the N. sativa cookies (2.5%, 5%, and 10%) and 10 mg/kg chloroquine for 5 consecutive days after the infection was established. The reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase, catalase, and hematological parameters (red cell indices, leukocytes, and its differentials) in the infected mice were determined. The inflammatory mediators, C-reactive protein (CRP), and myeloperoxidase (MPO) were also assayed. The result revealed that black seed had a total phenol content of 18.73 mgGAE/g and total flavonoid content of 0.36 mgQUE/g. The infected mice treated with N. sativa cookies showed significantly decreased parasitaemia, MDA, and ROS levels. Furthermore, the results showed significant suppression in proinflammatory mediators (CRP and MPO) levels and enhanced antioxidant status of infected mice treated with N. sativa. The study suggests that N. sativa could function as nutraceuticals in the management of Plasmodium infection associated with inflammatory and immunomodulatory disorders.

Dermaceutical Utilization of Nigella sativa Seeds: Applications and Opportunities

Skin diseases have recently become a major concern among people of all ages due to their highly visible symptoms and persistent and difficult treatment, which significantly impact their quality of life. Nigella sativa seeds, also known as "black seeds" or "kalonji," are one of the most commonly used herbal medicines due to their wide range of biological and pharmacological activities. It contains a wide range of bioactive constituents found in both fixed and essential oils. It has been used for hundreds of years as an alternative ethnomedicine to treat a wide range of skin conditions. N. sativa's dermatological applications in skin diseases are attributed to its potent antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory properties, making it an intriguing skincare candidate. Several studies unravelled positive results associated with N. sativa on skin diseases. As N. sativa is the most studied medicinal plant, several preclinical and clinical studies have been conducted to establish its use in the treatment of various skin diseases. Thymoquinone has anti-inflammatory, antioxidant, and antibacterial properties, which mainly contributed to the treatment of skin diseases. In this context, the present review explores all the available studies on the association of N. sativa and its effect on treating skin diseases in light of recent studies and patents supporting its therapeutic applications.

Effect of black seeds (Nigella sativa) on inflammatory and immunomodulatory markers in Plasmodium berghei-infected mice

Nigella sativa, a core dietary supplement and food additive in folklore is one of the most broadly studied seed plants in the global nutraceutical sector. Malaria infection impairs the ability of principal cells of the immune system to trigger an efficient inflammatory and immune response. Ninety-six mice, weighing 20-25 g, were grouped into 12 consisting of 8 animals each. The mice were infected with standard inoculum of the strain NK65 Plasmodium berghei (chloroquine sensitive) and the percentage parasitemia suppression were evaluated. The individual effect of black seed supplemented diet and its combinatory effect with chloroquine (CQ) were investigated on reactive oxygen species (ROS), glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione-S-transferase (GST), serum immunoglobulins (IgG and IgM), and the hematological parameters (hemoglobin, packed cell volume, and red blood cell count) in P. berghei infected mice. The inflammatory cytokines, tumor necrosis factor (TNF-α), interleukin (IL-6 and IL-10), as well as IgG and IgM were assayed in the serum. The mice temperature and behavioral changes were observed. Infected mice treated with the dietary supplementation of black seed with a percentage inclusion (2.5%, 5%, 10%) showed significantly decreased parasitemia and ROS levels (p < 0.05) compared with the untreated mice. The result demonstrated a significant suppression in the pro-inflammatory cytokines (TNF-α, IL-6) levels and a notable elevation in the anti-inflammatory cytokine (IL-10), antioxidant markers as well as the immunoglobulin levels of the P. berghei-infected mice treated with black seed. The study revealed that black seed enhanced host antioxidant status, modulated inflammatory and immune response by regulating some inflammatory cytokines and immunomodulatory mediators. PRACTICAL APPLICATIONS: Black seed (Nigella sativa) has been a dietary supplement and natural remedy for many centuries. Inflammatory and immune diseases are the most notable cause of mortality in the world and more than 50% of deaths have been attributed to it. However, there is paucity of information on the effect of N. sativa on anti-inflammatory and immunomodulatory ability during malaria infection. The result suggests that N. sativa produced antioxidant, anti-inflammatory, and immunomodulatory effect in Plasmodium berghei-infected mice via the participation of glutathione antioxidant system, serum antibodies, and some inflammatory cytokines.

A Narrative Review on Various Oil Extraction Methods, Encapsulation Processes, Fatty Acid Profiles, Oxidative Stability, and Medicinal Properties of Black Seed (Nigella sativa)

The current review investigates the effects of black seed (Nigella sativa) on human health, which is also used to encapsulate and oxidative stable in different food products. In recent decades, many extraction methods, such as cold pressing, supercritical fluid extraction, Soxhlet extraction, hydro distillation (HD) method, microwave-assisted extraction (MAE), ultrasound-assisted extraction, steam distillation, and accelerated solvent extraction (ASE) have been used to extract the oils from black seeds under optimal conditions. Black seed oil contains essential fatty acids, in which the major fatty acids are linoleic, oleic, and palmitic acids. The oxidative stability of black seed oil is very low, due to various environmental conditions or factors (temperature and light) affecting the stability. The oxidative stability of black seed oil has been increased by using encapsulation methods, including nanoprecipitation, ultra-sonication, spray-drying, nanoprecipitation, electrohydrodynamic, atomization, freeze-drying, a electrospray technique, and coaxial electrospraying. Black seed, oil, microcapsules, and their components have been used in various food processing, pharmaceutical, nutraceutical, and cosmetics industries as functional ingredients for multiple purposes. Black seed and oil contain thymoquinone as a major component, which has anti-oxidant, -diabetic, -inflammatory, -cancer, -viral, and -microbial properties, due to its phenolic compounds. Many clinical and experimental studies have indicated that the black seed and their by-products can be used to reduce the risk of cardiovascular diseases, chronic cancer, diabetes, oxidative stress, polycystic ovary syndrome, metabolic disorders, hypertension, asthma, and skin disorders. In this review, we are focusing on black seed oil composition and increasing the stability using different encapsulation methods. It is used in various food products to increase the human nutrition and health properties.

Black Seed (Nigella sativa): A Favourable Alternative Therapy for Inflammatory and Immune System Disorders

In the recent years, various food additives, medicinal plants, and their bioactive components have been utilized in anti-inflammatory and immunomodulatory therapy. Nigella sativa is a key dietary supplement and food additive which has a strong traditional background. It is also one of the most broadly studied seeds in the global pharmaceutical and nutraceutical sector. N. sativa seeds are potential sources of natural metabolite such as phenolic compounds and alkaloids. The anti-inflammatory and immunomodulatory abilities of these seeds, most peculiarly with reference to some inflammatory and immune mediators, are reviewed. N. sativa and its bioactive compounds modulate inflammatory and immunomodulatory mediators including tumor necrosis factor-alpha (TNF-α), interferon gamma (IFN-γ), nuclear factor kappa B (NF-kB) cyclooxygenase (COX), lipoxygenase (LOX), transforming growth factor beta (TGF-β), interleukins, and immunoglobulin levels. This paper comprehensively describes the biomarkers and signaling pathways underlying the anti-inflammatory and immunomodulatory potential of N. sativa. This review also explains the scientific basis and the pharmacological properties of core bioactive ingredients of N. sativa responsible for these biological activities which indicates that their bioactive components could be possibly regarded as favorable therapy for disorders linked to inflammation and immune-dysregulation.

Wild Egyptian medicinal plants show in vitro and in vivo cytotoxicity and antimalarial activities

Background

Medicinal plants have been successfully used as an alternative source of drugs for the treatment of microbial diseases. Finding a novel treatment for malaria is still challenging, and various extracts from different wild desert plants have been reported to have multiple medicinal uses for human public health, this study evaluated the antimalarial efficacy of several Egyptian plant extracts.

Methods

We assessed the cytotoxic potential of 13 plant extracts and their abilities to inhibit the in vitro growth of Plasmodium falciparum (3D7), and to treat infection with non-lethal Plasmodium yoelii 17XNL in an in vivo malaria model in BALB/c mice.

Results

In vitro screening identified four promising candidates, Trichodesma africanum, Artemisia judaica, Cleome droserifolia, and Vachellia tortilis, with weak-to-moderate activity against P. falciparum erythrocytic blood stages with mean half-maximal inhibitory concentration 50 (IC₅₀) of 11.7 μg/ml, 20.0 μg/ml, 32.1 μg/ml, and 40.0 μg/ml, respectively. Their selectivity index values were 35.2, 15.8, 11.5, and 13.8, respectively. Among these four candidates, T. africanum crude extract exhibited the highest parasite suppression in a murine malaria model against P. yoelii.

Conclusion

Our study identified novel natural antimalarial agents of plant origin that have potential for development into therapeutics for treating malaria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03566-5.

Antiplasmodial, antimalarial activities and toxicity of African medicinal plants: a systematic review of literature

BACKGROUND

Malaria still constitutes a major public health menace, especially in tropical and subtropical countries. Close to half a million people mainly children in Africa, die every year from the disease. With the rising resistance to frontline drugs (artemisinin-based combinations), there is a need to accelerate the discovery and development of newer anti-malarial drugs. A systematic review was conducted to identify the African medicinal plants with significant antiplasmodial and/or anti-malarial activity, toxicity, as wells as assessing the variation in their activity between study designs (in vitro and in vivo).

METHODS

Key health-related databases including Google Scholar, PubMed, PubMed Central, and Science Direct were searched for relevant literature on the antiplasmodial and anti-malarial activities of African medicinal plants.

RESULTS

In total, 200 research articles were identified, a majority of which were studies conducted in Nigeria. The selected research articles constituted 722 independent experiments evaluating 502 plant species. Of the 722 studies, 81.9%, 12.4%, and 5.5% were in vitro, in vivo, and combined in vitro and in vivo, respectively. The most frequently investigated plant species were Azadirachta indica, Zanthoxylum chalybeum, Picrilima nitida, and Nauclea latifolia meanwhile Fabaceae, Euphorbiaceae, Annonaceae, Rubiaceae, Rutaceae, Meliaceae, and Lamiaceae were the most frequently investigated plant families. Overall, 248 (34.3%), 241 (33.4%), and 233 (32.3%) of the studies reported very good, good, and moderate activity, respectively. Alchornea cordifolia, Flueggea virosa, Cryptolepis sanguinolenta, Zanthoxylum chalybeum, and Maytenus senegalensis gave consistently very good activity across the different studies. In all, only 31 (4.3%) of studies involved pure compounds and these had significantly (p = 0.044) higher antiplasmodial activity relative to crude extracts. Out of the 198 plant species tested for toxicity, 52 (26.3%) demonstrated some degree of toxicity, with toxicity most frequently reported with Azadirachta indica and Vernonia amygdalina. These species were equally the most frequently inactive plants reported. The leaves were the most frequently reported toxic part of plants used. Furthermore, toxicity was observed to decrease with increasing antiplasmodial activity.

CONCLUSIONS

Although there are many indigenous plants with considerable antiplasmodial and anti-malarial activity, the progress in the development of new anti-malarial drugs from African medicinal plants is still slothful, with only one clinical trial with Cochlospermum planchonii (Bixaceae) conducted to date. There is, therefore, the need to scale up anti-malarial drug discovery in the African region.

Recent Progress on Chemical Constituents and Pharmacological Effects of the Genus Nigella

Seeds of the genus Nigella plants as folk medicine are often used to prevent and treat asthma, diarrhea, dyslipidemia, and other diseases around the world. Pharmacological researches showed that seed extract and seed oil have antibacterial, antioxidant, hypoglycemic, and hepatoprotective effects which attributed to their bioactive constituents such as alkaloids, saponins, flavones, and phenols. This paper has covered recent progresses on chemical and pharmacological researches on these plants, including their compounds and pharmacological effects. It was found that the chemical component researches were focused on the seed oil. Therefore, more attention should be paid to the profile of the whole constituents in the seeds.

HPLC-DAD Analysis, Antioxidant and Protective Effects of Tunisian Rhanterium suaveolens against Acetamiprid Induced Oxidative Stress on Mice Erythrocytes

The present study was performed to assess the HPLC-DAD analysis as well as antioxidant and protective effects of Tunisian Rhanterium suaveolens (Rs) against acetamiprid (ACT) induced oxidative stress on mice erythrocytes. The in vitro assays showed that the methanolic extract of Rs has an impressive antioxidant effect proved by testing the total antioxidant and scavenging activities using BCB, DPPH and ABTS assays, respectively. Moreover, qualitative and quantitative analysis using HPLC-DAD revealed the richness of Rs in polyphenols where p-Coumaric, Apigenin-7-glucoside and Ferulic acid were detected as the most abundant polyphenols. In the in vivo experiment, ACT, used as a toxicity model, was given to mice at a dose of 20 mg/kg. The latter was the origin of hemolytic anemia characterized by a significant decrease in red blood cells, hemoglobin and hematocrit levels and an increase in bilirubin, LDH, osmotic fragility, reticulocytes and white blood cells number. Characteristic erythrocyte morphological alterations were also determined as spherocytosis, schistocytosis and dacryocystitis. The oxidative status of ACT-treated mice was also altered manifested by a significant increase in MDA and GSH levels and a decrease in SOD, CAT and GPx activities. When receiving the Rs methanolic extract at a dose of 300 mg/kg, all the parameters cited above were restored in mice. These remarkable corrections could only confirm the important antioxidant effect and the noticeable protective properties that possess Rs owing to its broad range of secondary bioactive metabolites.

Effects of Eugenol on Haemoproteus columbae in domestic pigeons (Columba livia domestica) from Riyadh, Saudi Arabia

Eugenol was investigated for the treatment of Haemoproteus columbae (H. columbae) infected squabs (young domestic pigeons, Columba domestica). Thirty naturally-infected squabs were divided into three groups of 10 each. One group was treated with Eugenol, while the positive and negative control groups were administered buparvaquone (Butalex®) and distilled water, respectively. The number of infected red blood cells (RBCs) was calculated in all groups before and after treatment at 4-day intervals for 16 days. The results showed a significant therapeutic effect of Eugenol, with a progressive decrease in the number of infected RBCs from 89.20 ± 2.11 before treatment to 0.90 ± 0.31 at the end of treatment (P≤0.05). Butalex® was able to suppress the number of infected RBCs from 93.70 ± 1.72 before treatment to 0.90 ± 0.35 at the end of the experiment (P≤0.05). Eugenol showed therapeutic effects against H. columbae and may be regarded as a candidate for further studies to develop new drugs against blood parasites, in both animals and humans.

Nigella sativa L. (Black Cumin): A Promising Natural Remedy for Wide Range of Illnesses

The seed of Nigella sativa (N. sativa) has been used in different civilization around the world for centuries to treat various animal and human ailments. So far, numerous studies demonstrated the seed of Nigella sativa and its main active constituent, thymoquinone, to be medicinally very effective against various illnesses including different chronic illness: neurological and mental illness, cardiovascular disorders, cancer, diabetes, inflammatory conditions, and infertility as well as various infectious diseases due to bacterial, fungal, parasitic, and viral infections. In spite of limited studies conducted so far, the promising efficacy of N. sativa against HIV/AIDS can be explored as an alternative option for the treatment of this pandemic disease after substantiating its full therapeutic efficacy. Moreover, the strong antioxidant property of this valued seed has recently gained increasing attention with regard to its potential role as dietary supplement with minimal side effects. Besides, when combined with different conventional chemotherapeutic agents, it synergizes their effects resulting in reducing the dosage of concomitantly used drugs with optimized efficacy and least and/or no toxicity. A number of pharmaceutical and biological properties have been ascribed to seeds of N. sativa. The present review focuses on the profile of high-value components along with traditional medicinal and biological principles of N. sativa seed and its oil so as to explore functional food and nutraceutical potential of this valued herb.

A Review on the Cosmeceutical and External Applications of Nigella sativa

It is estimated by the World Health Organization (WHO) that most of the world's population depends on herbal medicine for their health care. Nigella sativa (N. sativa), also known as black-caraway and as “Kalonji,” is a well-known seed all over the world. It is one of the most common medicinal plants worldwide and contains many useful chemical constituents that we can find in its fixed oil, such as thymoquinone, thymohydroquinone, dithymoquinone, thymol, nigellicine, carvacrol, nigellimine, nigellicine, nigellidine, and alpha-hederin. Due to these numerous important ingredients it was found that it affects different areas of our body and has many pharmacological effects as antibacterial, antiviral, anti-inflammatory, and wound healing effect and also for acne vulgaris, skin cancer, pigmentation, and many cosmeceutical applications. Based on the folklore usage of N. sativa seeds and oil, they are used in various systems of food and medicines. The aim of this article is to provide a detailed survey of the literature of cosmeceutical and external applications of N. sativa which is expected to stimulate further studies on this subject.

Anticancer activity of an ultrasonic nanoemulsion formulation of Nigella sativa L. essential oil on human breast cancer cells

Nigella sativa L. (NS) is a plant renowned in traditional holistic medicine systems for almost 1400 years because of its remarkable antioxidant, antimicrobial, anti-inflammatory and anti-cancer properties. The essential oil of N. sativa, in particular, possesses these significant biological properties. However, N. sativa essential oil has many insoluble constituents with properties that have not been fully explored. Nanoemulsion-based insoluble formulations are a widely used carrier system for lipophilic materials. In the present study, we used ultrasonic emulsification, polysorbate 80 and water to formulate a highly stable N. sativa essential oil nanoemulsion (NSEO-NE). To optimize the NSEO-NE preparation, we changed the surfactant concentration, the oil-surfactant mixing ratio and the emulsification time. The droplet size distribution and morphology of the prepared NE was analyzed using dynamic light scattering and scanning electron microscopy, respectively. The droplet size of the NSEO-NE was approximately 20-50 nm in diameter. The anticancer properties of the NE preparation were studied using a modified methyl-thiazolyl-diphenyl tetrazolium bromide (MTT) assay as well as cellular uptake and nuclear morphological analyses. The NSEO-NE significantly reduced the viability of Michigan Cancer Foundation-7 (MCF-7) breast cancer cells. The nucleo-cytoplasmic morphological features of NSEO-NE-treated cells included cell membrane blebbing, cytoplasmic vacuolation, marginalization of chromatin, and fragmentation of the nucleus. The results clearly indicate that NSEO-NE induced apoptosis in MCF-7 cells. These findings support the potential application of NSEO-NE in breast cancer therapy, and also merit future translational research.

Potential antimalarial activity of Methyl Jasmonate and its effect on lipid profiles in Plasmodium Berghei infected mice

BACKGROUND

The antimalarial activity and lipid profiles of Methyl Jasmonate (MJ) were investigated against established malaria infection in vivo using BALB/c mice.

METHODS

Arteether (AE) and chloroquine (CQ) were used as reference drugs while ethanol was used as the vehicle for drug delivery for MJ.

RESULTS

Mice treated with 10 and 25 mg/kg MJ showed a remarkable reduction in percentage parasitemia by 68.3% and 78.2% on day 10(post treatment) respectively while 45.4% and 87.2% reduction in percentage parasitemia were observed in the group treated with 50 mg/kg on day 3 and 10 (post treatment) respectively. The highest mean survival time was observed in CQ followed by AE and MJ in dose-dependent manner. A progressive decrease in packed cell volume (PCV) was observed in infected untreated mice which led to the death of all the mice by day 9 (post treatment). Infected mice treated with MJ showed reduced level of HDL and LDL compared with infected untreated group. As the dose of MJ increased in infected mice cholesterol levels increased while there was reduction in triglyceride.

CONCLUSION

Overall there was marked decrease in parasitemia in Plasmodium berghei infected mice treated with graded doses of MJ but appears to have reduced antimalarial activity compared with CQ and AE.

Leishmanicidal and cytotoxic activities of Nigella sativa and its active principle, thymoquinone

CONTEXT

Leishmaniasis is a complex disease with a broad spectrum of clinical presentations.

OBJECTIVE

We evaluated the anti-leishmanial effects of Nigella sativa L. (Ranunculaceae) against Leishmania tropica and Leishmania infantum with an in vitro model.

MATERIALS AND METHODS

Antileishmanial effects of essential oil and methanolic extract of N. sativa (0-200 µg/mL) and thymoquinone (0-25 µg/mL) on promastigotes of both species and their cytotoxicity activities against murine macrophages were evaluated using the MTT assay at 24, 48, and 72 h. Moreover, their leishmanicidal effects against amastigotes were investigated in a macrophage model, for 48 and 72 h.

RESULTS

The findings showed that essential oil (L. tropica IC50 9.3 μg/mL and L. infantum IC50 11.7 μg/mL) and methanolic extract (L. tropica IC50 14.8 μg/mL and L. infantum IC50 15.7 μg/mL) of N. sativa, particularly thymoquinone (L. tropica IC50 1.16 μg/mL and L. infantum IC50 1.47 μg/mL), had potent antileishmanial activity on promastigotes of both species after 72 h. In addition, essential oil (L. tropica IC50 21.4 μg/mL and L. infantum IC50 26.3 μg/mL), methanolic extract (L. tropica IC50 30.8 μg/mL and L. infantum IC50 34.6 μg/mL), and thymoquinone (L. tropica IC50 2.1 μg/mL and L. infantum IC50 2.6 μg/mL) mediated a significant decrease in the growth rate of amastigote forms of both species. Thymoquinone (CC50 38.8 μg/mL) exhibited higher cytotoxic effects against murine macrophages than the other extracts.

CONCLUSION

N. sativa, especially its active principle, thymoquinone, showed a potent leishmanicidal activity against L. tropica and L.infantum with an in vitro model.

Ameliorative Effects of Curcumin on Artesunate-Induced Subchronic Toxicity in Testis of Swiss Albino Male Mice

India is one of the endemic areas where control of malaria has become a formidable task. Artesunate is the current antimalarial drug used to treat malaria, especially chloroquine resistant. The objective of the present study was to investigate the dose-dependent effect of oral administration of artesunate on the oxidative parameters in testes of adult male Swiss albino mice and ameliorative efficacy of curcumin, a widely used antioxidant. An oral dose of 150 mg/kg body weight (bwt; low dose) and 300 mg/kg bwt (high dose) of artesunate was administered for a period of 45 days to male mice, and ameliorative efficacy of curcumin was also assessed. The results revealed that artesunate caused significant alteration in oxidative parameters in dose-dependent manner. Administration of artesunate brought about significant decrease in activities of superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase, whereas lipid peroxidation and glutathione-S-transferase activity were found to be significantly increased. The results obtained show that oxidative insult is incurred upon the intracellular antioxidant system of testis tissue by artesunate treatment. Further, administration of curcumin at the dose level of 80 mg/kg bwt along with both doses of artesunate attenuated adverse effects in male mice.

Effects of formaldehyde inhalation on humoral immunity and protective effect of Nigella sativa oil: An experimental study

AIM

This study was carried out to determine the effects of formaldehyde (FA) inhalation on the humoral immunity of rats and the protective effect of Nigella sativa (NS) oil.

MATERIALS AND METHODS

The rats (n = 33) were divided into five groups, with five animals in the control group (FA-free air) and seven in the other four groups. Group FA1 was exposed to FA (5 ppm), group FA + NS1 was treated with NS and exposed to FA (5 ppm), group FA2 was exposed to FA (10 ppm), and group FA + NS2 was treated with NS and exposed to FA (10 ppm). At the end of a 4-week study period, blood samples were collected. Enzyme-linked immunosorbent assay was used to determine the levels of serum total immunoglobulin A (IgA), total immunoglobulin M (IgM), total immunoglobulin G (IgG), and complement 3 (C3).

RESULTS

FA inhalation significantly increased serum IgA, IgM, and C3 levels and decreased serum IgG levels compared with the control group. NS administration decreased serum IgA, IgM, and C3 levels, which were induced by FA inhalation.

CONCLUSION

FA inhalation significantly increased acute antibody responses and C3 levels in a dose-dependent manner compared with the control group. FA inhalation decreased the secondary immune response compared with the control group. Levels of acute antibody responses and complement following exposure to FA inhalation returned to normal following treatment with NS (immunoregulatory effect). However, NS did not affect the secondary immune response.

Scolicidal effects of black cumin seed (Nigella sativa) essential oil on hydatid cysts

Surgery remains the preferred treatment for hydatid cyst (cystic echinococcosis, CE). Various scolicidal agents have been used for inactivation of protoscolices during surgery, but most of them are associated with adverse side effects. The present study aimed to evaluate the in vitro scolicidal effect of Nigella sativa (Ranunculaceae) essential oil and also its active principle, thymoquinone, against protoscolices of hydatid cysts. Protoscolices were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations of the essential oil (0.01-10 mg/ml) and thymoquinone (0.125-1.0 mg/ml) were used for 5 to 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining. Furthermore, the components of the N. sativa essential oil were identified by gas chromatography/mass spectroscopy (GC/MS). Our study revealed that the essential oil of N. sativa at the concentration of 10 mg/ml and its main component, thymoquinone, at the concentration of 1 mg/ml had potent scolicidal activities against protoscolices of Echinococcus granulosus after 10 min exposure. Moreover, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%), and longifolene (6.1%) were found to be the major components of N. sativa essential oil by GC/MS analysis. The results of this study indicated the potential of N. sativa as a natural source for production of a new scolicidal agent for use in hydatid cyst surgery. However, further studies will be needed to confirm these results by checking the essential oil and its active component in in vivo models.

Dietary supplementation of chloroquine with nigella sativa seed and oil extracts in the treatment of malaria induced in mice with plasmodium berghei

BACKGROUND

The aim of the study was to investigate the effects of dietary combination of Nigella sativa seed and oil extracts with chloroquine (CQ), and how these combinations enhance CQ efficacy in mice infected with Plasmodium berghei and their survival rates.

MATERIALS AND METHODS

Chloroquine sensitive P. berghei, NK65 strain was used for the study. This was passaged intraperitoneally into albino mice with a 0.2ml standard inoculum consisting of 10(6) parasitized erythrocyte suspension in phosphate buffer solution (PBS). Parasitaemia was ascertained by microscopical examination of blood films under oil immersion at X100 magnification.

RESULTS

Nigella sativa seed in feed (NSSF), NSSF + CQ on day 4, produced 86.1% and 86.0% suppression respectively, while Nigella sativa oil extract in feed (NSOF) and in combination with CQ had 86.0% and 99.9% suppression respectively. The degree of suppression with the combination was significantly higher compared to CQ alone (P < 0.001) (36.1%). Complete parasitaemia clearance was obtained on the 20(th) and 15(th) day of treatment for NSSF, NSSF + CQ respectively, while that for NSOF and NSOF + CQ was on days 26 and 12 respectively. For CQ parasite clearance was 12 days with treatment. Also, the combinastion of 10 mg/kg Nigella sativa oil treatment injected intraperitoneally with oral CQ produced very significant parasite suppression (P < 0.0001) (93%). Survival rate in NSSF and NSOF and in combination with CQ groups was 100 and 60.0% for CQ alone.

CONCLUSIONS

This study shows that the use of Nigella sativa seed and oil extract as dietary supplements in combination with CQ has a potential in enhancing the efficacy of CQ and could be of benefit in management of malaria.

Protective effect of quercetin on chloroquine-induced oxidative stress and hepatotoxicity in mice

The present study was aimed to find out the protective effect of quercetin on hepatotoxicity resulting by commonly used antimalarial drug chloroquine (CQ). Swiss albino mice were administered with different amounts of CQ ranging from human therapeutic equivalent of 360 mg/kg body wt. to as high as 2000 mg/kg body wt. We observed statistically significant generation of reactive oxygen species, liver toxicity, and oxidative stress. Our observation of alterations in biochemical parameters was strongly supported by real-time PCR measurement of mRNA expression of key biochemical enzymes involved in hepatic toxicity and oxidative stress. However, the observed hepatotoxicity and accompanying oxidative stress following CQ administration show dose specific pattern with little or apparently no effect at therapeutic dose while having severe effects at higher dosages. We further tested quercetin, an antioxidant flavanoid, against CQ-induced hepatoxicity and found encouraging results as quercetin was able to drastically reduce the oxidative stress and hepatotoxicity resulting at higher dosages of CQ administration. In conclusion, our study strongly suggests co administration of antioxidant flavonoid like quercetin along with CQ for antimalarial therapy. This is particularly important when CQ is administered as long-term prophylactic treatment for malaria as chronic exposure has shown to be resulting in higher dose level of drug in the body.

Oxidative stress in malaria

Malaria is a significant public health problem in more than 100 countries and causes an estimated 200 million new infections every year. Despite the significant effort to eradicate this dangerous disease, lack of complete knowledge of its physiopathology compromises the success in this enterprise. In this paper we review oxidative stress mechanisms involved in the disease and discuss the potential benefits of antioxidant supplementation as an adjuvant antimalarial strategy.