[ study of anti-microbial effect of pycnocycla spinosa's fruit extracts]

Infectious diseases account for approximately one-half of all deaths in tropical country. In developed country, despite the progress made on the control of disease, incidence of epidemics due to drug resistant microorganisms and unknown diseases spreading microbes pose enormous public health concerns. On the other hand, in spite of improvements in food production hygiene, food safety is increasingly an important health issue. There is, therefore, still a need for new antimicrobial agent to reduce or eliminate foodborne pathogen as well as food spoilage microorganisms. Historically, plants play a major role in primary health-care as therapeutic remedies in developing countries. The screening of plant extracts has been of great interest to scientists for the discovery of new drugs effective in the treatment of infectious disease. Umbelleferea is known to be a potential source for the antimicrobial agents. The present study attempts to investigate the antimicrobial activity of Pycnocycla spinosa as a member of Umbelleferea against selected microorganisms. The plants were collected from Isfahan and different solvent extracts of plants were prepared. Then, the antimicrobial activity of extract was determined, using disk diffusion method. The minimal inhibitory concentration [MIC] was determined by tube dilution method. Results demonstrated that different extracts of plants indicate antimicrobial activity against bacills subtilis, aspergilus niger and candida albicans. Generally, the antimicrobial activity of the plant's fruit extracts is considered medium. Pycnocycla spinosa fruit's extract showed medium antimicrobial activity. Hydroalcoholic extract of the fruit demonstrated higher antimicrobial activity. This may reflect a low concentration of active components in extracts. Further studies are needed to investigate antimicrobial activity of the plant's essential oil and other parts of the plant

Evaluation of antibacterial activity of ethanol extracts of some medicinal plants against Listeria monocytogenes

Listeria monocytogenes is a foodborne pathogen capable of causing outbreak or sporadic episodes in human. Most of the outbreak or sporadic episodes were in the last two decades and due to high rate of mortality, caused a great concern in food industries. There are various medicinal plants with the high performance of antibacterial activity in Iran. The present study investigated the anti-listerial activity of some of these palnts against two serotypes of foodborne L. monocytogenes. The plants were used included: Thymus vulgaris L., Eucalyptus globulus Labill. Matricaria recutita L, Rosmarinus officinalis L and Saliva officinalis L. The plants were selected and identified by Pharmacognosy Department of Isfahan Faculty of Pharmacy. Extracts of the selected plants were prepared. Then antibacterial activity of these extracts was determined by disc diffusion method. The Minimal Inhibitory Concentration [MIC] and Minimum Bactericidal Concentration [MBC] were also determined by the serial dilution method. Ampicillin [10 micro g/disc] used in the test as standard. Only ethanolic extract of Eucalyptus showed antibacterial effects against L. monocyiogenes in both disc diffusion and serial dilution method. MIC and MBC of this extract were 31.25 micro g/ml and 500 micro g/ml, respectively. There was no significant difference between the sensitivity of the two serotypes. Extract of other plants did not show any antibacterial effects against L. monocytogenes. Based on our results, only the extract of Eucalyptus showed antibacterial effects on both serotypes. Using other extraction methods and higher concentration of extracts may cause stronger antibacterial effect on L. monocytogenes