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Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives.

SummaryThe prevalence of antibiotic-resistant Escherichia coli isolates from faecal samples from 117 poultry industry workers, 100 patients and119 healthy chicken were compared. Resistance of E. coli chicken isolates to ampicillin, chloramphenicol, gentamicin, spectinomycin, tetracycline and trimethoprim ϩ sulphamethoxazole (TMP ϩ SMX) (range 57% -99.1%) were significantly higher than those isolated from patients (range 21.9% -71.4%) and workers (range 35% -71.8%). However, for drugs not used in poultry, such as amoxicillin ϩ cluvalanate (AMX ϩ CLV), ceftazidime and nitrofurantoin, resistance rates of chicken isolates (range 0% -2.6%) were significantly lower than those of patient isolates (range 8.7% -30%). Resistance to spectinomycin reached 96% in E. coli chicken isolates and 71% in organisms isolated from humans. Use of this drug in Saudi Arabia is mostly limited to veterinary purposes. Multidrug resistance is alarmingly high in all groups but was highest in chicken isolates (77.4%). Serotyping of E. coli isolates showed that 27% of the organisms isolated from patients were overlapping with 10.9% of the chicken isolates, indicating the possibility of chicken being a source of the resistance pool for humans. We therefore call for the banning of antibiotics in the poultry industry as growth promoters and recommend that their use be restricted to treating infections.

It has been reported that Nigella sativa oil possesses hepatoprotective effects in some models of liver toxicity. However, it is N. sativa seeds that are used in the treatment of liver ailments in folk medicine rather than its oil. Therefore, the aim of this study was to investigate the effect of the aqueous suspension of N. sativa on carbon tetrachloride (CCL4)-induced liver damage. Aqueous suspension of the seeds was given orally at two dose levels (250 mg/kg and 500 mg/kg) for five days. CCL4 (250 microl/kg intraperitoneally / day in olive oil) was given to the experimental group on days 4 and 5, while the control group was only treated with the vehicles. Animals treated with CCL4 showed remarkable centrilobular fatty changes and moderate inflammatory infiltrate in the form of neutrophil and mononuclear cells when compared to the controls. This effect was significantly decreased in animals pretreated with N. sativa. Histopathological or biochemical changes were not evident following administration of N. sativa alone. Serum levels of aspartic transaminase (AST), and L-alanine aminotransferase (ALT) were slightly decreased while lactate dehydrogenase (LDH) was significantly increased in animals treated with CCL4 when compared to the control group. LDH was restored to normal but ALT and AST levels were increased in animals pretreated with N. sativa. In conclusion, N. sativa seeds appeared to be safe and possibly protective against CCL4-induced hepatotoxicity. However, further studies may still be needed prior to supporting its use in folk medicine for hepatic diseases.

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Samples of market-ready chicken muscle and liver from 32 local broiler farms were first screened for antibiotic residues by microbiological assay. The antibiotic-residue-positive muscles and livers from 22 farms were further analysed for norfloxacin (NFX) residues by high performance liquid chromatography. NFX was detected in 35.0% and 56.7% of raw antibiotic-residue-positive muscles and livers, respectively. The NFX-positive muscles and livers were respectively obtained from 11 (50.0%) and 14 (63.6%) of the 22 antibiotic-residue-positive farms. Since the maximum residue limit (MRL) for NFX has not yet been fixed, the MRL for enrofloxacin was used in the study. All NFX-positive farms had mean raw tissue levels, which were 2.7- to 34.3-fold higher than the MRL. Although cooking markedly reduced NFX tissue concentrations, mean detectable levels remained above MRL in large proportions of NFX-positive samples and farms. Susceptibility patterns of Enterobacteriaceae isolates from chicken and human patients to NFX showed alarmingly high rates of resistance in chicken isolates especially among Escherichia coli (45.9%) and Pseudomonas spp. (70.6%) compared with patients' isolates (10.5% and 18.2%, respectively). The study reveals widespread misuse of NFX in the local poultry industry, which may pose a major risk to public health including possible stimulation of bacterial resistance and hypersensitivity reactions to fluoroquinolones. More prudent use of fluoroquinolones in food-producing animals is therefore recommended. Further, there is a need to establish MRL values for NFX.

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Background:The use of antimicrobial agents in food-producing animals has become an important public health issue due to the spread of microbial resistance. This study was aimed at identifying the antimicrobial agents available for poultry use and highlighting their possible impact on public health. Materials and Methods: Twenty-three randomly selected poultry farms and all veterinary pharmacies in the Eastern Province of Saudi Arabia were surveyed for the antibiotics used or dispensed. Further, a comprehensive literature survey was performed. Results: Twenty-nine antimicrobial agents were identified as being available for poultry use, of which 22 (75.9%) were important for the treatment of human infections. Enrofloxacin, oxytetracycline, ampicillin, neomycin, sulphamethoxazole, colistin, doxycycline and erythromycin were the most frequently used drugs. Food-borne hypersensitivity reactions and the emergence of microbial resistance, as well as cross-resistance to the various groups of antibiotics in animals and its transfer to human pathogens, are well documented. Conclusion:The misuse of antibiotics in the local poultry industry poses a serious health risk to the public and may complicate the treatment of human infections. The veterinary use of antimicrobial agents, especially those with dual animal and human applications, should therefore be restricted. The establishment of a government department concerned with food and drug safety is also highly recommended.