Comparison of antioxidant and anti-radical activities of methanolic extract of edible leafy vegetables

Aerobic organisms have efficient antioxidant systems but diet can reduce oxidative stress through antioxidants supplementation. It seems that oxidative stress has a major role in cancer, atherosclerosis and aging process. This research was conducted in order to assess and compare the antioxidant and antiradical properties of edible leafy vegetable [Leek, Garden Cress, Spearmint, Basil, Tarragon and Coriander]. Methanolic extracts of dried vegetables were prepared and their antioxidant and antiradical properties were determined using linoleic acid emulsion system and DPPH method respectively. It was shown that highest extraction yield [11.62%] was belonged to Garden Cress and Basil had least [4.42%] extraction yield. Methanolic extract of tarragon had best efficiency in acid linoleic emulsion [induction period was 60.3h when control was 13.4h]. In DPPH system, Spearmint and tarragon showed highest activity though minimum IC50 [216 micrograms/milliliter] was belonged to spearmint. This was even smaller than of IC50 of BHT though the differences between Spearmint, BHT and tarragon were not significant. Leek had Highest IC50 [11675 micrograms/milliliter] as calculated by extrapolation. It was concluded that tarragon and spearmint have highest antiradical and antioxidant activity

In vitro antimicrobial activity of the essential oil of Ziziphora clinopodioides L. on food spoilage and pathogenic bacteria

The genus Ziziphora clinopodioides Lam. [Lamiaceae] are grown in most part of Iran. This plant has been used as an additive in yoghurt and other dairy products, but there is little study about antimicrobial activity of Ziziphora clinopodioides on food spoilage and pathogenic bacteria. The main goal of this study was to evaluate the antimicrobial activity of the essential oil of Ziziphora clinopodioides against some food spoilage and pathogenic bacteria and determine Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC]. Essential oil of Ziziphora [Ziziphora clinopodioides L.] was tested for it s growth inhibitory and bactericidal effect on 6 Gram-negetive [Enterobacter aerogenes, Escherichia coil, Klebsiella pneumoniae, Salmonella enteritidis, Pseudomonas aeroginosa and Shigella dysenteria] and 3 Gram-positive species [Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus]. Minimum inhibitory concentration [MIC] was determined using dilution method and minimum bactericidal concentration [MBC] was taken from the concentration of the lowest dosed test tube showing no growth on subcultured. All test organism were inhibited by Ziziphora clinopodioides L. except Pseudomonas aeroginosa and Shigella dysenteria. The MIC and MBC for Gram-negetive bacteria, including Enterobacter aerogenes, Escherichia coil, Klebsiella pneumoniae and Salmonella enteritidis were 250, 500,125 and 250 /tg/ml respctivily. The MIC for Gram-negetive bacteria, including Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus were 125, 1000, 125 /g/ml respctivily. It is concluded that essential oil of ziziphora has antimicrobial activity on food spoilage and pathogenic bacteria. According to the results of this study, It is applicable to use essential oil of Ziziphora as the natural preservatives and flavoring agents in food products