The anti-inflammatory, analgesic and antipyretic activity of Nigella sativa

Effect of Annona senegalensis rootbark extracts on Naja nigricotlis nigricotlis venom in rats

Annona senegalensis Pers (family: Annonaceae) is used traditionally in Nigeria to treat victims of snakebite. The potency of the methanol extract of the root bark of the plant was tested against cobra (Naja nigricotlis nigricotlis Wetch) venom in rats. The extract was also tested on brine shrimp (Artemia saline Leach). The activity of the extract against the venom induced mortality, occurrence of toxic signs, activity on liver enzymes as well as its ability to reverse experimentally induced increase in body temperature were evaluated. Results indicated that the extract caused reduction in the induced hyperthermia and directly detoxified the snake venom used by 16-33%. It, however, failed to restore the biochemical functions (sGOT and sGPT) of the liver. The extract exhibited an LC(50) of 232.7 microg/ml in the brine shrimp test.

Black cumin seed essential oil, as a potent analgesic and antiinflammatory drug

The steam-distilled essential oil of Iranian black cumin seed (Nigella sativa L.) was investigated for its composition and analgesic and antiinflammatory properties. After oil analysis by GC/MS, 20 compounds were identified in the oil, obtained in 0.4% (v/w) yield. Among them, para-cymene (37.3%) and thymoquinone (13.7%) were the major components. Acetic acid-induced writhing, formalin and light tail flick tests were used for assessment of analgesic activity. Antiinflammatory activity was evaluated using carrageenan-induced paw oedema in rats and croton oil-induced ear oedema in mice. Black cumin seed essential oil (BCSEO) was found to produce a significant analgesic effect in acetic acid-induced writhing, formalin and light tail flick tests. Naloxone, an opioid antagonist, could not reverse the analgesic effect observed in the formalin test. Although oral administration of BCSEO at doses of 100, 200 and 400 micro L/kg did not exert a significant antiinflammatory effect in the carrageenan test, i.p. injection of the same doses significantly (p < 0.001) inhibited carrageenan-induced paw oedema. BCSEO at doses of 10 and 20 micro L/ear could also reduce croton oil-induced oedema. It seems that mechanism(s) other than opioid receptors is (are) involved in the analgesic effect of BCSEO since naloxone could not reverse this effect. Both systemic and local administration of BCSEO showed antiinflammatory activity. Thymoquinone, as one of the major components of BCSEO, probably has an important role in these pharmacological effects.

Effect of Nigella sativa (black seed) on subjective feeling in patients with allergic diseases

Nigella sativa (black seed) is an important medicinal herb. In many Arabian, Asian and African countries, black seed oil is used as a natural remedy for a wide range of diseases, including various allergies. The plant's mechanism of action is still largely unknown. Due to the lack of study data on its efficacy in allergies, four studies on the clinical efficacy of Nigella sativa in allergic diseases are presented. In these studies, a total of 152 patients with allergic diseases (allergic rhinitis, bronchial asthma, atopic eczema) were treated with Nigella sativa oil, given in capsules at a dose of 40 to 80 mg/kg/day. The patients scored the subjective severity of target symptoms using a predefined scale. The following laboratory parameters were investigated: IgE, eosinophil count, endogenous cortisol in plasma and urine, ACTH, triglycerides, total cholesterol, LDL and HDL cholesterol and lymphocyte subpopulations. The score of subjective feeling decreased over the course of treatment with black seed oil in all four studies. A slight decrease in plasma triglycerides and a discrete increase in HDL cholesterol occurred while the lymphocyte subpopulations, endogenous cortisol levels and ACTH release remained unchanged. Black seed oil therefore proved to be an effective adjuvant for the treatment of allergic diseases.

Plants used in cosmetics

This review describes the use of some natural products in cosmetic preparations, due to their low mammalian toxicity, with a brief description of the major use, plant parts used, the actives responsible for effect and the benefits of such products. Their use in skin care; such as dryness, eczema, acne, free-radical scavenging, antiinflammatory, antiaging and skin protection effects are explained, and also the use in hair care as hair growth stimulants, hair colorants, and for hair and scalp complaints such as dandruff. Essential oils when incorporated into finished products impart many benefits such as a pleasant aroma in perfumery, shine or conditioning effects in hair care products, emolliency and improving the elasticity of the skin.

Anticonvulsant effects of thymoquinone, the major constituent of Nigella sativa seeds, in mice

The anticonvulsant effects of thymoquinone, the major constituent of Nigella sativa seeds, were investigated using pentylenetetrazole (PTZ)- and maximal electroshock (MES)-induced seizure models. We also studied the effect of thymoquinone on pentobarbital-induced hypnosis, locomotor activity, and motor coordination. In PTZ-induced seizure, the intraperitoneally injection of thymoquinone with doses of 40 and 80 mg/kg, prolonged the onset of seizures and reduced the duration of myoclonic seizures. The protective effect of thymoquinone against mortality was 71.4% and 100% in the mentioned doses, respectively. In MES model, thymoquinone failed to reduce the duration of seizure, whereas exhibited a complete protection against mortality. In PTZ model, flumazenil (10 mg/kg, i.p.), an antagonist of benzodiazepine (BZD) site in the GABAA-BZD receptor complex, inhibited the prolongation of seizure latency, but did not show any effect on the duration of myoclonic seizures. Also, pretreatment with naloxone (0.1 and 03 mg/kg, i.p.) inhibited the prolongation of myoclonic seizure latency and antagonized the reduction of myoclonic seizure duration induced by thymoquinone (40 and 80 mg/kg) in the PTZ model. Moreover, thymoquinone (40 and 80 mg/kg) did not have any hypnosis effect in the pentobarbital-induced hypnosis, but impaired the motor coordination and reduced the locomotor activity. These results indicate that thymoquinone may have anticonvulsant activity in the petit mal epilepsy probably through an opioid receptor-mediated increase in GABAergic tone.

Thymoquinone and Nigella sativa oil protection against methionine-induced hyperhomocysteinemia in rats

Although the state of hyperhomocysteinemia (HHcy) appears to be associated with higher risks of coronary, cerebral and peripheral vascular disease as well as with a number of other clinical conditions, the underlying molecular mechanisms are not fully elucidated. There is strong evidence, however, that HHcy could induce a pathogenic state of oxidative stress. The interest in modulating the elevated levels of total homocysteine in HHcy and/or their negative impacts through preventive strategies, particularly through the supplementation with vitamins that may be linked to the homeostasis of homocysteine (folate, vitamin B(12), and vitamin B(6)), has increased in recent years. Here we show that active antioxidant components of the traditionally used black seeds of Nigella sativa plant protect against the development of methionine-induced HHcy and its associated state of oxidative stress. Pretreatment of rats with an oral dose of 100 mg/kg of thymoquinone, the main active constituent of the black seed, for 30 min and for 1 week almost completely protected against induced HHcy measured 5 h after methionine load (100 mg/kg). Under similar conditions pretreatment with commercial black seed oil (100 microl/kg) for 30 min and for 1 week produced significant and strong protection levels of 74.2 and 94.5%, respectively. Under the state of induced HHcy there were significant increases in the plasma levels of triglycerides, lipid peroxidation, cholesterol and in the activities of glutathione peroxidase and superoxide dismutase. Catalase activity was not affected. The total antioxidant status, however, was significantly depressed. All of these effects were almost totally blocked by prior treatment with thymoquinone or black seed oil. These findings may contribute towards a protective measure utilizing the black seed against the negative impacts of HHcy.

Studies on the use of Cassia singueana in malaria ethnopharmacy

Cassia singueana (Family: Fabaceae) is used in northern Nigeria for the treatment of acute malaria attack. We investigated the activities of the methanol extract of the root bark of this plant against rodent plasmodia infection, nociception, pyrexia and inflammation in mice and rats. The studies were carried out using acetic acid-induced writhing, hot plate algesia, rodent plasmodia (Plasmodium berghei) in mice; formalin test, yeast-induced pyrexia and egg-albumin-induced inflammation in rats. The results showed that the extract exhibited significant antinociceptive, antipyretic and antiplasmodial activity in all the models used. Phytochemical screening of the extract revealed the presence of phenols, saponins, tannins and some traces of anthraquinones. The LD50 of the extract was established to be 847+/-30 mg/kg, i.p. in mice. The observed pharmacological activities might be the scientific basis for the folkloric use of the plant in treating acute malaria attack. The study also paves way for the possible development of it, as a phytodrug against malaria.

Pharmacological evidence favouring the folkloric use of Diospyros mespiliformis Hochst in the relief of pain and fever

The methanol extract of Diospyros mespiliformis was evaluated for its claimed folkloric usage in the relief of pain and fever. Antipyretic, analgesic and anti-inflammatory effects of the extract were evaluated in rats and mice. Studies were carried out on yeast-induced pyrexia in rats, acetic acid-induced writhing in mice, formalin test and egg albumin-induced anti-inflammatory activity in rats. The extract (50 and 100 mg/kg i.p.) gave a potent antipyretic effect for 100 mg/kg and significant activity (P<0.05) against all the analgesic and anti-inflammatory models used. The LD(50) of the extract was estimated to be 513.80+/-33.92 mg/kg i.p. in mice. These results provide support for the use of the plant in relieving pain and fever.