Clinical application of cyclophosphamide (CP) as an anticancer drug is often limited due to its toxicity. CP is metabolized mainly in the liver by cytochrome P450 system into acrolein which is the proximate toxic metabolite. Many different natural antioxidants were found to alleviate the toxic effects of various toxic agents via different mechanisms. Therefore, the present study aimed at investigating the role of essential oils extracted from fennel, cumin and clove as natural antioxidants in the alleviation of hepatotoxicity induced by CP through assessment of hepatotoxicity biomarkers (AST, ALT, ALP), histopathology of liver tissues as well as other biochemical parameters involved in the metabolism of CP. The data of the present study showed that treatment of male mice with cyclophosphamide (2.5 mg/Kg BW) as repeated dose for 28 consecutive days was found to induce hepatotoxicity through the elevation in the activities of AST, ALT, and ALP. Combined administration of any of these oils with CP to mice partially normalized the altered hepatic biochemical markers caused by CP, whereas administration of fennel, clove or cumin essential oils alone couldn’t change liver function indices. Moreover, CP caused histological changes in livers of mice including swelling and dilation in sinusoidal space, inflammation in portal tract and hepatocytes, as well as, hyperplasia in Kuppfer cells. However, co-administration of any of the essential oils with CP alleviated to some extent the changes caused by CP but not as the normal liver. CP was also found to induce free radical levels (measured as thiobarbituric acid reactive substances) and inhibited the activities of superoxide dismutase, glutathione reductase, and catalase as well as activities and protein expressions of both glutathione S-transferase (GSTπ) and glutathione peroxidase. Essential oils restored changes in activities of antioxidant enzymes (SOD, CAT, GR, GST, and GPx) caused by CP to their normal levels compared to control group. In addition, treatment of mice with CP was found to induce the protein expression of CYP 3A4, 2B1/2, 2C6, 2C23. Moreover, the present study showed that essential oils reduced the expression of CYPs 2E1, 3A4 but could not restore the expression of CYP 2C6 and 2C23 compared to CP-treated mice. Interestingly, pretreatment of mice with essential oil of clove was found to restore activities of DMN-dI, AHH, and ECOD which were induced by CP to their normal control levels. It is concluded that EOs showed a marked hepatoprotective effect against hepatotoxicity induced by CP. In addition, co-administration of CP with any of these oils might be used as a new strategy for cancer treatment to alleviate the hepatotoxicity induced by CP.

The prevalence of enterotoxigenic Staphylococcus aureus was investigated among 200 participants working in three different food processing plants in Egypt. Using skin swabs, 75 (38%) of the 200 tested persons were positive for the presence of S. aureus. Of the S. aureus positive persons, 28 (14%) harboured S. aureus produced staphylococcal enterotoxins. The serotypes of these enterotoxins were enterotoxin A (68%), enterotoxin B (36%), enterotoxin C (46%) and enterotoxin D (18%). Some of these isolates produced more than one type of enterotoxins namely AB, AC, BC, BD, ABC and ACD. Analysis of risk factors implicated in skin carriage of S. aureus as age, gender, marital status, education, duration in employment, frequency and method of hand wash and incidence of chronic skin infection revealed insignificant association with staphylococcal skin carriage. The obtained results put forth the risk of food contracting contamination with enterotoxigenic strains of S. aureus owing to skin colonization of S. aureus among food handlers.

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Abstract:The antibacterial activity of essential oils hydrodistilled from local anise, coriander, cumin, marjoram, rosemary and thyme were screened against a group of food-borne pathogens comprising Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Escherichia coli O157:H7, Salmonella Typhimurium and Bacillus cereus. All the tested bacterial strains displayed varying degrees of susceptibility towards the examined oils. Nevertheless Gram-positive bacterial strains were more sensitive than Gram-negative organisms. Furthermore, the antimicrobial activities of the extracted essential oils were found to be related to their major components as identified by Gas chromatography-Mass spectroscopy. Essential oils containing phenolic or aldehydic terpenoids as major constituents were the most active (thyme and cumin oils), followed by those containing alcoholic terpenoids (marjoram and coriander oils). Meanwhile, essential oils containing ketonic terpenoids as major components were moderately active (rosemary oil) and those containing phenolic ethers exhibited relatively weak activity (anise oil). In food industries, the tested essential oils can be used as natural antimicrobial agents in the light of shift away from artificial agents and the move towards natural alternatives.

Gas chromatography/mass spectroscopy analysis was performed to identify the chemical components of three extracted essential oils including thyme, marjoram, and sage. The antibacterial activity of the extracted essential oils againstPseudomonas aeruginosa(ATCC 9027) was investigated using disc diffusion assay, either alone or in combination with standard antibiotics (piperacillin, cefepime, meropenem, gentamicin, and norfloxacin). Results showed that the studied oils exhibited a variety of activities against the tested bacterium. Thyme oil was the most active followed by marjoram oil, whereas sage displayed no activity towards the tested organism. Thyme oil enhanced the antibacterial activity of cell wall targeting antibiotics (piperacillin, cefepime, and meropenem) by more than twofold. Marjoram oil potentiated the activity of all the tested antibiotics except norfloxacin. Sage, despite its inactivity againstpseudomonas, synergistically enhanced the activity of piperacillin, meropenem, and gentamicin. Thyme essential oil, containing thymol as a major component (33.6%), exhibited higher activity alone or in combination with antibiotics than marjoram which contained alcoholic terpenes or sage essential oil that contained 1,8-cineole as its major component (29%). The investigated oils, as natural bioactive agents, may be used to enhance the activity of antibiotics towardspseudomonas.

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Due to the looming spread of resistance to classical antimicrobial agents, innovative therapeutic methods are in dire need to combat the onslaught of resistant bacterial pathogens. This study examines the antimicrobial efficacy of a phytochemical and a metallic nanoparticle against the top Gram positive resistant pathogen. The potential synergy of these two agents was also evaluated. The antibacterial activity of thymol and silver nanoparticles were tested individually using disc diffusion technique. The extent of synergy of their combination was evaluated using the checkerboard assay. Twenty clinical isolates of Staphylococcus aureus characterized as methicillin resistant or methicillin sensitive Staphylococcus aureus were utilized and the extent of synergism was calculated from fractional inhibitory concentration indices. Thymol exhibited an antistaphylococcal activity regardless of whether the isolates were phenotypically resistant or sensitive to methicillin. Combining thymol with silver nanoparticles resulted in at least additive or synergistic effect for all the examined strains and methicillin resistant strains were inhibited in the combinatorial assays to a greater extent comparative to when silver nanoparticles or thymol were used singly.

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