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Nigella species have been widely used in traditional medicine. The aim of this study was to evaluate the antiinflammatory and analgesic potentials of Nigella orientalis L. seeds fixed oil (NOO). The acetic acid writhing test and the formaldehyde-induced licking paw were performed to assess the analgesic activity of the oil. The antiinflammatory activity was first evaluated in vitro by the erythrocyte membrane stabilization then in vivo by xylene- and carrageenan-induced ear and paw edema, respectively. To further understand the molecular mechanism of action of the Nigella extract, lipopolysaccharide-activated RAW 264.7 macrophages were used. Nitric oxide (NO) production was measured by Griess reaction and cell viability by MTT assay. The gene and protein expression of inflammatory mediators were assessed by RT-PCR and western blot, respectively. NOO exerted a potent analgesic effect in in vivo models of writhing test and induced edema. The analyzed molecular mechanisms revealed a role for NO and prostaglandins as molecules mediating the pharmacological effects of the extract through a mechanism involving nuclear factor-κB and mitogen-activated protein kinases. This study demonstrates, for the first time, that the fixed oil of N. orientalis has strong antinociceptive and antiinflammatory properties and might be a promising agent for the treatment of certain inflammation-related diseases.

Due to continuous rise in antibiotic resistance, there is a need for alternative treatment options to reduce the levels of oral pathogens for the maintenance of oral as well as overall health. The aim of this study was to evaluate the in vitro antibacterial potential of tinctures of Spilanthes oleracea and propolis, Nigella seed oil, and an ethanolic extract of black garlic on microorganisms involved in oral diseases. Both the minimum inhibitory concentration assay and the minimum bactericidal/fungicidal concentration assay were used in this study. Inhibition effects against total human salivary bacteria were also determined. Our results show that all of the preparations tested had potent antimicrobial activities. When measured 10 min after exposure, even low concentrations of the propolis tincture were found to have killed more than 99% of salivary bacteria, whereas Spilanthes tincture and black garlic extract killed more than 90% and Nigella seed oil more than 60% of the pathogens. This suggests that all preparations are promising candidates for the use in oral health care products and that all have the potential to control biofilm associated infections.

Nigella orientalis and N. segetalis fixed oils were administered orally (1 mL/kg/day) to Wistar Kyoto rats for 4 weeks. The effects of the oils on biochemical parameters were compared with a control group that received distilled water under identical conditions. LDL-cholesterol level was decreased significantly in both oil groups while serum total cholesterol and VLDL-cholesterol were decreased significantly following administration of only N. orientalis fixed oil when compared with the control group. The HDL-cholesterol levels were increased significantly in both oil groups.N. orientalis fixed oil significantly reduced Aspartateaminotransferase (AST), Alkaline Phosphatase (ALP), bilirubin and urea levels in rats. There was an increase in the albumin, uric acid and mean corpuscular volume (MCV) concentrations, while the mean corpuscular hemoglobin concentration (MCHC) and RDW (red cell distribution width) levels decreased significantly. In N. segetalis fixed oil treated rats, the levels of ALP, Blood Urea Nitrogen (BUN), MCHC, RDW were decreased significantly, whereas a significant increase was found in albumin, fibrinogen, Hematocrit (HCT) and MCV levels. The effects of 4 weeks oral intake of N. orientalis and N. segetalis fixed oils on blood malondialdehyde (MDA) and total antioxidant status (TOS) were also investigated in rats. The study showed that the oils had no significant effect on MDA production. N. orientalis and N. segetalis fixed oils caused a significant increase in the total antioxidant status in rats.

The effects of seven medicinal plants including Artemisia herba-alba, Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium, Trigonella foenum-graecum, and Allium sativum on protein degradation, lipid peroxidation, erythrocyte deformability and osmotic fragility of erythrocytes exposed in vitro to 10 mM H2O2 for 60 min at 37 °C have been examined. Preincubation of erythrocytes with Nigella sativa and Allium sativum protected erythrocytes against protein degradation, loss of deformability and increased osmotic fragility caused by H2O2, while the other plants failed to protect erythrocytes against these damages. Artemisia herba-alba did not protect erythrocytes against lipid peroxidation, while Trigonella foenum-graecum unexpectedly increased lipid peroxidation of erythrocytes exposed to H2O2. Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium and Allium sativum protected erythrocytes against lipid peroxidation. The results indicate the importance of oxidatively damaged cellular proteins in compromising the rheologic behaviour of the erythrocytes, and that the medicinal plants which have anti-protein-oxidant activity (e.g. Nigella sativa and Allium sativum) could be rheologically useful, particularly in pathological conditions related to free radicals. Copyright © 2004 John Wiley & Sons, Ltd.

The constituents of Nigella sativa modulate the immune system. The aim of the present work was to study the effectiveness of Nigella sativa oil in RA patients. Data from 40 female RA patients diagnosed according to the 2010 ACR/EULAR were analysed and discussed. The patients took two placebo (starch filled) capsules daily for 1 month. This was followed by a month of Nigella sativa oil capsules 500 mg twice/day. The disease activity score (DAS-28) significantly decreased after receiving the Nigella sativa capsules (4.55 ± 0.82) compared with before and after placebo (4.98 ± 0.79 and 4.99 ± 0.72, respectively) (p = 0.017). Similarly, the number of swollen joints and the duration of morning stiffness improved. A marked improvement in the disease activity was shown by both the ACR20 and EULAR response criteria in 42.5% and 30% of the patients, respectively, after intake of Nigella. Supplementation with Nigella sativa during DMARD therapy in RA may be considered an affordable potential adjuvant biological therapy.

The essential oil of black cumin seeds, Nigella sativa L., was tested for a possible antioxidant activity. A rapid evaluation for antioxidants, using two TLC screening methods, showed that thymoquinone and the components carvacrol, t-anethole and 4-terpineol demonstrated respectable radical scavenging property. These four constituents and the essential oil possessed variable antioxidant activity when tested in the diphenylpicrylhydracyl assay for non-specific hydrogen atom or electron donating activity. They were also effective.OH radical scavenging agents in the assay for non-enzymatic lipid peroxidation in liposomes and the deoxyribose degradation assay. GC-MS analysis of the essential oil obtained from six different samples of Nigella sativa seeds and from a commercial fixed oil showed that the qualitative composition of the volatile compounds was almost identical. Differences were mainly restricted to the quantitative composition.

We used the yeast estrogen screen (YES) containing a human estrogen receptor to evaluate the estrogenic activity of extracts obtained from Nigella damascena seeds. Alcohol extracts obtained by direct extraction of seeds showed a low estrogenic activity, while the alcohol extract obtained after extraction with solvents of increasing polarity showed a strong estrogenic activity. This suggests the presence in Nigella of polar components whose activity can be clearly demonstrated after previous elimination of interacting apolar components that may mask the activity of more polar components. The response of both alcohol fractions follow a bell-shaped curve indicating a concentration-dependent relationship.

The volatile oil of Nigella sativa seeds was prominent in in vitro anti-shigella activity against eight multiple drug resistant strains of Shigella flexneri. The anti-shigella activity against Shigella flexneri Y SH-4 was observed in the sera of monkeys after 45–60 min of oral administration of the oil. It exhibited promising in vivo anti-shigella activity against the same strain when tested in monkey models with experimental shigellosis, fully curing the infected monkeys within 3 days. The rectal swabs of the experimental groups became free of the challenge organism on day 3 of treatment with the volatile oil. © 1998 John Wiley & Sons, Ltd.