Showing papers on "Thymoquinone published in 2003"

Pharmacological and toxicological properties of Nigella sativa

Abstract: The seeds of Nigella sativa Linn. (Ranunculaceae), commonly known as black seed or black cumin, are used in folk (herbal) medicine all over the world for the treatment and prevention of a number of diseases and conditions that include asthma, diarrhoea and dyslipidaemia. This article reviews the main reports of the pharmacological and toxicological properties of N. sativa and its constituents. The seeds contain both fixed and essential oils, proteins, alkaloids and saponin. Much of the biological activity of the seeds has been shown to be due to thymoquinone, the major component of the essential oil, but which is also present in the fi ed oil. The pharmacological actions of the crude extracts of the seeds (and some of its active constituents, e.g. volatile oil and thymoquinone) that have been reported include protection against nephrotoxicity and hepatotoxicity induced by either disease or chemicals. The seeds/oil have antiinflammatory, analgesic, antipyretic, antimicrobial and antineoplastic activity. The oil decreases blood pressure and increases respiration. Treatment of rats with the seed extract for up to 12 weeks has been reported to induce changes in the haemogram that include an increase in both the packed cell volume (PCV) and haemoglobin (Hb), and a decrease in plasma concentrations of cholesterol, triglycerides and glucose. The seeds are characterized by a very low degree of toxicity. Two cases of contact dermatitis in two individuals have been reported following topical use. Administration of either the seed extract or its oil has been shown not to induce significant adverse effects on liver or kidney functions. It would appear that the beneficial effects of the use of the seeds and thymoquinone might be related to their cytoprotective and antioxidant actions, and to their effect on some mediators of inflammation.

Thymoquinone is a potent superoxide anion scavenger

Abstract: The antioxidant and pro-oxidant effects of thymoquinone (TQ), a natural main constituent of the volatile oil of Nigella saliva seeds, and a synthetic structurally-related tert-butylhydroquinone (TBHQ), were examined in vitro. Both TQ and TBHQ efficiently inhibited iron-dependent microsomal lipid peroxidation in a concentration-dependent manner with median inhibitory concentration (IC50) values of 16.8 and 14.9 microM, respectively. TBHQ was stronger than TQ as a scavenger of 2,2'-diphenyl-p-picrylhydrazyl radical (DPPH) (IC50 = 5 microM, 200 times more active than TQ) and as a scavenger of hydroxyl radical (OH*) with an IC50 of 4.6 microM (approximately 10 times more active than TQ). TQ was more active than TBHQ as a superoxide anion scavenger with IC50 of 3.35 microM compared to 18.1 microM for TBHQ. Only TBHQ significantly promoted DNA damage in the bleomycin-Fe(III) system. The results suggest that both TQ and TBHQ have strong antioxidant potentials through scavenging ability of different free radicals. Moreover, the data indicate that TQ is acting mainly as a potent superoxide anion scavenger.

In vitro inhibition of growth and induction of apoptosis in cancer cell lines by thymoquinone

Abstract: Thymoquinone (TQ) is likely responsible for the chemotherapeutic effects of N. sativa extract; however, the cellular mechanisms remain ill-defined. TQ-induced cytotoxicity was investigated using canine osteosarcoma (COS31), its cisplatin-resistant variant (COS31/rCDDP), human breast adenocarcinoma (MCF7), human ovarian adenocarcinoma (BG-1) and Madin-Darby canine (MDCK) cell lines. TQ-induced cytotoxicity was determined using a proliferation assay (MTT assay) and apoptosis assays. Effects of TQ on the cell cycle were determined using flow cytometry. COS31/rCDDP resistant cells were the most sensitive cell line to TQ and MDCK cells were the least sensitive. TQ (25 micro M) induced apoptosis of COS31 cells 6 h after treatment and decreased the number of COS31 cells in S-phase and increased cells in G1-phase, indicating cell cycle arrest at G1. These results suggest that TQ kills cancer cells by a process that involves apoptosis and cell cycle arrest. Non-cancerous cells are relatively resistant to TQ.

Improvement of experimental allergic encephalomyelitis (EAE) by thymoquinone; an oxidative stress inhibitor.

Abstract: UNLABELLED Experimental Allergic Encephalomyelitis (EAE) is an autoimmune demyelinating disease of the central nervous system that is widely accepted as an animal model for the human multiple sclerosis. Oxidative stress appears to play a role in the onset and progression of EAE. We reasoned that decreasing oxidative stress might ameliorate symptoms and signs of EAE. Thymoquinone is reported to inhibit oxidative stress. One way of decreasing oxidative stress is to induce glutathione (GSH). We tested the impact of Thymoquinone (1 mg/kg, injected at tail vein) in our EAE model. We induced (EAE) in female Lewis rats using myelin basic protein emulsified with complete Freund's adjuvant. 24 animals were placed into three groups: A) Rats with EAE B) EAE rats with concomitant five day injection of Thymoquinone days 1-5, C) EAE rats with five doses of Thymoquinone injected at day 12-17. Twenty-eight days later, animals were sacrificed; spinal cord tissues collected for glutathione (GSH). RESULTS 63% of animals in group "A" developed hind limb weakness and/or paralysis while 37% developed mild tail weakness, perivascular inflammation and low spinal cord GSH level. 25% of animals in group "B" exhibited mild tail and hind limb weakness and 75% animals had no symptoms, no perivascular inflammation and high spinal cord GSH level. 63% of animals of group "C" showed improving symptoms following Thymoquinone injections, no perivascular inflammation and higher GSH level while 37% of animals showed no symptoms prior and post Thymoquinone injections. Clinical symptoms correlated well with perivascular inflammation and GSH level. Animals received Thymoquinone at day 12-17 had higher GSH level, no perivascular inflammation and no symptoms compared with other groups. CONCLUSION Thymoquinone inhibited oxidative stress which leads into improvement in our EAE animals. Thymoquinone may have a role in treatment of Multiple Sclerosis.

A simple differential pulse polarographic method for the determination of thymoquinone in black seed oil.

Abstract: A reliable and simple differential pulse polarographic method is described for the determination of thymoquinone in black seed oil. The polarographic behaviour of thymoquinone was examined in various buffer systems over the pH range 5.0-10.0. Thymoquinone is reduced in a single, reversible peak at the dropping mercury electrode. The differential pulse polarogram showed a distinct peak in Sorensen buffer:methanol (3:7, v/v; pH 8.5) at a peak potential of -0.095 V (vs. silver/silver chloride electrode), and a plot of peak height against concentration was found to be linear over the range 0.2-15.0 microg/mL (R = 0.9998). The limit of detection was calculated to be 0.054 microg/mL. The polarographic method has been applied to determine thymoquinone in two black seed oil preparations available on the Austrian pharmaceutical market.

Supercritical Fluid Extraction of the Egyptian Rosemary (Rosmarinus officinalis) Leaves and Nigella sativa L. Seeds Volatile Oils and Their Antioxidant Activities

Abstract: Volatile oils of rosemary (Rosmarinus Officinalis) leaves and nigella sativa L seeds were isolated by supercritical fluid extraction (SFE) under suitable conditions of pressure and temperature. The isolated volatile oils were analysed by gas chromatography-mass spectrometry (GC-MS). The main components in rosemary oil are, 1,8–cineole (52.31 %), α- pinene (6.54 %), caryophyllene (z) (5.48 %) while the components, in nigella are,thymoquinone (41.05 %), β-cymene (10.64 %) and caryophyllene (1.89 %). The estimated compounds in both oils were grouped into four main classes, namely, monoterpene hydrocarbons, light oxygenated compounds, heavy oxygenated compounds and sesquiterpene hydrocarbons. The light oxygenated compounds in both oils recorded the highest values compared with the other classes, where 1,8–cineol and thymoquinone were the main components of this group in both rosemary and nigella volatile oils, respectively. Nigella volatile oil contains a considerable phenolic content (2.69 %); mostl...

Effects of Thymoquinone, the Major Constituent of Nigella sativa Seeds, on the Contractile Responses of Rat vas Deferens

Abstract: We have evaluated the effects of thymoquinone on smooth muscle contraction in the isolated rat epididymal vas deferens using tension recording technique. The contractile responses to norepinephrine (NE), KCl, and electrical field stimulation were recorded using an isometric transducer. Thymoquinone inhibited the contractile responses to exogenous NE (100 µM) and KCl (80 mM) in a concentration-dependent manner. Moreover, thymoquinone reduced the amplitude of electrically-evoked contraction of vas deferens in a concentration-dependent manner. Cumulative addition concentrations of CaCl2 (0.1–10 mM) to tissue bath failed to increase the amplitude of contractile responses to electrical field stimulation in the presence of thymoquinone (80 µM). These results indicate that thymoquinone induced non-selective and concentration-dependent inhibition of contractile responses to NE, KCl, and electrical field stimulation. This action may be due to the ability of this alkaloid to interfere with the mobilization of Ca2+ ...

Study of the nigella satival oil on gastric secretion and gastric mucosal lesion induced by oral indomethacin in albino rats

Abstract: The black seed (Nigella sativa), a member of the Runuculaccae family, is an annual plant growing in countries bordering the Mediterranean sea (Jansen, 1981). It is one of the native plants that arc widely distributed in Egypt (Hashem and EI·Kiey, 1982). In Arabian folk medicine, the black seed and its constituents, especially oils, have been used for treatment of many diseases such as diabetes. hypertension, bronchial asthma and rheumatism (Hashem and El-Kiey, 1982). Moreover. Nigclla sativa seeds are digestive stimulants as well as carminative. diuretic, ami-hclmintic.antitumor activity (Hassan and EI-Dakhakhny, 1992). an immune modulating effect (El-Kadi et al., 1987) and cytoprotectivc effect on tissues exposed to cytotoxic agents (El-Kadl et at, 1987). It is reponed that the seeds contain fixed and volatile oils which contain thyrnoquinone (El-Dakhakhny, 1995). It has been reported that thymoquinone protects organs sgainst oxidative damage induced by a variety of free radical generating agents (EI-Tahir et at, 1993). It was reported also that thyrnoquinone has an anri-Inflammatory activity in rats and inhibits eicosanoids generation inleukocytes (Ligumsky et al., 1995) and non enzymatic peroxid.nion in brain phospholipid liposornes (Kolbasa et al., 1998). Thymoquinone reduces free radical generation especially hydroxyl radicals. These hydroxyl radicals arc known to playamajor role in the pathogenesis of gastric mucosal ulcer (Kolbasa et at, 1998).Indomethacin is widely used in treating many diseases as rheumatic diseases, gout and fevers. Many roxie and side effects can be seen due to the use or abuse of indomethacin, especially those related to the gastroimestinal tract due to its local irritant effect, that leads to gastric erosion and ulceration (Houghton et al., 1995). It is clear that Nigella sativa has a very low toxicity on oral administration (Zaoui et al., 2002). so the present work was done to study the ability of Nigella sativa oil as a cytoprotective agent against oxidative gastric mucosal damage induced by local irritanteffect of indomethacin in albino rats, Also, the study of the histological effect of indomethacin on gastric mucosa and effect of Nigella sativa oil on gastric mucosal lesion induced by indomethacin were studied.