Antimicrobial activities of Iranian sumac and avishan-e shirazi by 203x8y1

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									Antimicrobial activities of Iranian sumac and
               avishan-e shirazi
(Zataria multiflora) against some food-borne

          Food Control 18 (2007) 646–649

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1. Introduction

   Food-borne diseases are still a major
    concern in some developing countries.

   Spices are herbal products which have
    been safely used by people around the
    world to impart desirable flavors and
    aromas to the local foods.

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   Several of these spices and their essential oil
    extracts have been reported to posses
    antimicrobial activities including garlic, savory,
    basil, laurel, mint, cumin, onion, sumac and

   Rhus coriaria L. (known as sumagh in Persian and
    sumach in Turkish) is a wild plant grown in Iran,
    Turkey and Mediterranean coastline.

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   Sumac has a sour and acidic taste and
    is traditionally used as a table spice in
    the region but is prepared differently in
    Iran and Turkey.

   What is called sumagh in Iran is in fact
    pure ground fruit epicarps of the plant
    while in Turkey the whole fruit is ground
    with salt crystals.

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   In traditional medicine sumac is used as
    astringent agent .
    (Wetheritlt & Pala, 1994)

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Zataria multiflora Boiss,
(avishan-e shirazi or Persian thyme)
   a native Iranian plant (Amin, 1991)

   Thymus kotschanus Boiss & Hohen and
    Ziziphora clinopodioides Lam are also
    called as avishan in Iran (Amin, 1991).

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   Avishan-e shirazi has a strong and
    pleasant aroma and is currently added
    into fast foods, e.g., pizzas.

   The spice extract has also been
    compared with Myrtus communis in
    treatment of recurrent aphthous
    stomatitis (Jafari et al., 2003).

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                    Table 1

             Yields of ethanolic extracts of sumac and avishan-e shirazi

Common plant name              Species name               Family name                Parts used             Extract yield (%)

Sumac (Sumagh)              Rhus coriaria L.          Anacardiaceae                Fruit epicarp                43.6a

Avishan-e shirazi       Zataria multiXora Boiss.            Labiatae               Aerial parts                 21.0a
(Persian thyme, zaatar)

  a Values were calculated as weight of dried extracts by weight of plant starting material and are means of three

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2. Materials and methods
    Six Gram-positive and Gram-negative food-
     borne pathogens

1.   Bacillus cereus PTCC 1274,
2.   Staphylococcus aureus 6539-P and
3.   Escherichia coli ATCC 8739
4.   Proteus vulgaris
5.   Salmonella typhi
6.   Shigella flexneri

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   Stock cultures of bacteria were kept in 20%
    glycerol PBS (phosphate buffered saline)
    at -70 °C.

   Active cultures were generated by
    inoculating 100 µl of the thawed microbial
    stock suspensions into 5ml nutrient broth
    (Merck, Germany) followed by overnight
    incubation at 37 °C.
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   Freshly synchronized cultures of bacterial strains were
    prepared by successively transferring 100 µl of the
    vegetative cells into Muller Hinton broth and incubating
    for 24 h at 37 °C.

   The cells were harvested by centrifugation at 1600g for
    10min, washed with PBS, spun at 1600 again and diluted
    in sterile water to obtain 108 bacteria/ml as estimated by
    the surface plate counting method (Swanson, Busta,
    Peterson, & Johnson,1992).

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            3. Results and discussion
           Table 2
         Activity of sumac and avishan-e shirazi ethanolic extracts against
         foodborne bacteria in disc and well diVusion assays
     Food-borne bacteria                      Inhibition zones in mm
                                           Sumac a              Avishan-e shirazi a            Gentamycin b

     Bacillus cereus                          27 (21) c               26 (20)                          (26)
     Staphylococcus aureus                    30 (20)                 30 (25)                          (19)
     Escherichia coli                         24 (17)                 22 (10)                          (17)
     Proteus vulgaris                         24 (18)                 24 (12)                          (19)
     Salmonella typhi                         24 (17)                 24 (9)                           (20)
     Shigella Xexneri                         30 (20)                 22 (14)                          (20)
a   20 mg and 50 mg of the extracts were applied on disc and well diVusion experiments, respectively.
b   Positive control discs contained 30 g of gentamycin.
C   Values quoted are means of three determinations. Results of disc diVusion are quoted in parenthesis.

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          Table 3
Minimum inhibitory concentrations (MICs) and minimum bactericidal
concentrations (MBCs) of sumac and avishan-e shirazi extracts against
some food-borne bacterial strains
       Food-borne bacteria                     MICs                                 MBCs
                                           Sumac            Avishan-e           Sumac            Avishan-e
                                                            shirazi                              shirazi

    Bacillus cereus                       0.05 a             0.40                nd                 nd
    Staphylococcus aureus                 0.10               0.40                0.40               0.80
    Escherichia coli                      0.20               0.40                nd                 0.80
    Proteus vulgaris                      0.10               0.40                1.60               nd
    Salmonella typhi                      0.20               0.80                0.80               1.60
    Shigella Xexneri                      0.20               0.40                0.40                0.40

nd : not detected.
a The MIC and MBC values are quoted as percentages; the minimum concentration at which 100% inhibition was
observed. The values are means of three replicates.

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   Both spices were effective on both Gram-
    positive and Gram-negative bacteria but
    sumac showed to be more potent having
    MIC values 2–8 times less than avishan-e

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   Iranian sumac consisting solely of Rhus coriaria
    L. fruit epicarps used in this study showed
    better antibacterial activities compared to
    Turkish sumac consisting of the whole Rhus
    coriaria L. fruits (Nasar-Abbas & Kadir
    Halkman, 2004).

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