[Study of chemical composition of essential oil of Afsantine [Artemisia absinthium] and inhibitory effects of the essential oil and its aqueous and alcoholic extracts on some food borne bacterial pathogens]

Increasing human knowledge about adverse effects of chemical preservatives has increased public interest to consume products with natural preservatives such as plant extract and their essential oils. In this study chemical composition of essential oil of Afsantine and antibacterial effect of its essential oil and aqueous, ethanolic and methanolic extracts against the most important food borne pathogens, Salmonella typhimurium, Listeria monocytogenes, E. coli O157:H7, Bacillus cereus and Staphylococcus aureus were evaluated. Gas Chromatography-Mass Spectrometry [GC-MS] method was used for chemical composition analysis of the essential oil. Disk diffusion method was done to screen bacterial sensitivity. The Minimum Inhibitory Concentrations [MIC] of extracts were evaluated by broth micro-dilution method. The essential oil components were identified and the major constituents of the oil were Beta Thujone [29.75%] and Phellandrene [20.20%]. In disk diffusion method the most sensitive strain to the essential oil and the extracts was S. typhimurium and E.coli O157:H7. MICs of Afsantine essential oil against S. aureus and L. monocytogenes were estimated 3000 ppm. The methanolic extract showed antimicrobial activity against L. monocytogenes, E.coli O157:H7, B. cereus and S. aureus were estimated 10, 10, 8 and 4 mg ml-1, respectively. The results of this study revealed that the essential oil and methanlic extract of Afsantine have greater antimicrobial effects on given strains and might be used as a natural preservative in food system.

[Antibacterial effect of aqueous and alcoholic extracts from petal of saffron [Crocus sativus L.] on some foodborne bacterial pathogens]

Health concerns due to adverse effects of chemical preservatives have increased public interest to consuming preservative-free products or product containing natural preservatives such as plant extract and their essential oils. In this study the antibacterial effect of aqueous, ethanolic and methanolic extracts from petal of saffron against the most important foodborne pathogens Salmonella typhimurium, Listeria monocytogenes, E. coli O157: H7, Bacillus cereus and Staphylococcus aureus were evaluated. Disk diffusion method was done to screen bacterial sensitivity. The minimum inhibitory concentration [MIC] of extracts were evaluated by agar dilution and broth microdilution method. The most sensitive strain to extracts was S. typhimurium, and the most resistant strains were S. aureus and E. coli O157:H7. MICs of all extracts were estimated 40 mgml[-1], against all bacteria using agar dilution method. The aqua and methanolic extracts showed antimicrobial activity against all of bacteria by broth microdilution and MIC estimated 40 mgml[-1], however MIC of ethanolic extracts estimated 40 mgml[-1] for L. monocytogenes, S. aureus and B. cereus, while the MICs for S. typhimurium and E. coli O157:H7 were estimated >40 mgml[-1]. The results of this study revealed that the studied extracts might be potential sources of natural antimicrobial agents, and propose their potential application in food system as a natural preservative

[Effect of zataria multiflora boiss. essential oil on the growth of listeria monocytogenes in salted fish]

Essential oils and their components have antimicrobial effects. They use with spices as flavoring agents all over the world. They have been used safely since ancient times as herbal medicines. Zataria multiflora Boiss. is one of medicinal herbs in Iran and its antimicrobial effects on foodborne pathogens have to investigate in foodstuff. The aim of this study was to determine of the effect of Zataria multiflora Boiss. Essential oil on the growth of Listeria monocytogenes in salted [4%] silver carp. Effect of different concentrations of this Essential oil [0.0%, 0.045%, 0.135%, 0.405%, and 0.810%] on behavior of Listeria monocytogenes was determined by evaluation of the bacterial growth in salted fish fillets. The essential oil in used concentrations had significant inhibitory effect on the growth of Listeria monocytogenes in salted fish during the storage time. The higher concentration until 0.405%, the more significant inhibitory effects on the growth of Listeria monocytogenes [p<0.05] but 0.405% and 0.810% concentrations had no different significant inhibitory effects on the growth of Listeria monocytogenes [p>0.05]. Organoleptical survey showed that the concentrations of the essential oil used until 0.405% not only had no undesirable effect on flavoring but also it improve taste and flavor of salted fish. The result suggested that the Zataria multiflora Boiss. Essential oil can be considered as a natural preservative in salted fish

[Effect of Zataria multiflora Boiss. essential oil on the behavior of Vibrio parahaemolyticus in salted fish]

Thyme [Zataria multiflora Boiss.] is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current food borne intoxications. The aim of this study was to evaluate the antimicrobial activity of Zataria multiflora Boiss. essential oil on V. parahaemolyticus in salted [8% Nacl in tissue] silver carp. Effect of different concentrations of this Essential oil [0.0%, 0.045%, 0.135%, 0.405%, 0.810%] on behavior of V. parahaemolyticus in two temperatures [15, 25 C] was determined by evaluation of the bacterial growth in salted fish fillets. The essential oil in used concentrations had significant inhibitory effect on the growth of V. parahaemolyticus in salted fish compare with control treatment during the storage time [p<0.05]. There was no significant difference between all treatments. The results showed that Zataria multiflora Boiss. Essential oil had inhibitory effect on V. parahaemolyticus, therefore it can be considered as a natural preservative in salted fish

[ study on the radiographic incidence of multiple roots and canals in mandibular premolars in an Iranian population [research]]

A thorough knowledge of root canal anatomy and an understanding of its potential anatomic variations are essential for a successful root canal therapy. The most probable reason for failure is the inability to recognize the numerous variations in canal morphology. Mandibular premolars due to such anatomic variations, are considered the most difficult teeth for root canal therapy. If the entire root canal system is not properly located and treated, failure and flare- ups would follow. The purpose of this study was to evaluate the incidence of multiple roots and canals radiographically in mandibular premolars among an Iranian population referred to dental faculty of Shiraz University. One thousand and one hunrdeel [1100] full mouth series [FMS] radiographs of patients undergoing periodontal treatment were randomly selected. From among these radiographs, those full mouth series with four mandibular premolars free of any kind of root canal therapy, were included in the present study. Consequently, 1052 FMS were evaluated. From 2104 mandibular first premolars, 15% had more than one canal and 1.5% had more than one root. Among mandibular second premolars, 77 teeth [3.65%] had more than one canal where as 9 teeth had more than on root. There were 107 cases with more than one canal bilaterally, from among them in 8 cases all four mandibular premolars had more than one canal, in 12 cases three mandibular premolars had multiple canals bilaterally and in [87] remaining cases only two. mandibular premolars had bilaterally multiple canals. In nine cases of mandibular premolars. Multiple canals were observed bilaterally. The results of this study suggest that the probable incidence of multiple canals among mandibular first premolars is greater than mandibular second premolars. The frequency a multiple roots and canals in mandibular premolars are not affected by sex type. Since conventional radiographs in the department of periodontics are taken at a vertical angle to the teeth buccal surface, the probability of hiding multiple canals is high. Therefore, the mentioned results should be considered as the minimum probable cases for multiple roots among the teeth under investigation