[Hairy root induction in Burdock [arctium lappa L.]]

Arctium lappa is a medicinal plant, which natively grows in Iran. Arctiin and arctigenin are two of the most important secondary metabolites produced in this plant and used as anticancer reagents. Application of biotechnological methods for increasing the production of these metabolites is very essential. Recently, induction of hairy roots in plants to improve the production of desirable secondary metabolites has been considered. In this study, hairy roots were induced in Arctium lappa using Agrobacterium rhizogenes, strain AR15834. The leaf explants and seedlings of Burdock were used for the hairy roots induction. The leaf explants were turned brown and died when cultured in vitro. To improve the viability of these explants, different antioxidants including ascorbic acid [ASC], citric acid [CIT], polyvinylpyrrolidone [PVP] and L-cysteine were added to the MS medium, in different concentrations either alone or in combination with each other. Polymerase Chain Reaction [PCR] for rolB gene confirmed the morphological identification of the transformed hairy roots. Although the best antioxidant reagent was PVP 0.5% [w/v], it did not stop tissues browning of the leaf explants when they were co-cultured with A. rhizogenes for the hairy roots induction. When the two or three weeks old seedling were used for the hairy roots induction, the roots were observed 2 weeks after the bacterial infection with 5% frequency. In this study, A. rhizogenes induced hairy roots in Burdock. To the best of our knowledge, this is a first report on the hairy roots induction in Arctium lappa

[Biochemical and antimicrobial activities of salvia officinalis L. and mentha piperita L. essential oils]

Although antibiotics are used in conventional treatment of infectious diseases, a lot of unexpected side effects along with resistance to antibiotics appear. Salvia officinalis and Mentha piperita are plants found abundantly in most parts of Iran. In the present study, we extracted and identified the chemical compounds of the essential oils of Salvia officinalis and Mentha piperita. Moreover, the anti-oxidative property, free radical scavenging capacity, and antimicrobial activities of the essential oils of these plants were studied. This study was conducted in the Biotechnology Department laboratories, Agricultural Faculty of Avicina University, Hamadan, Iran, in 2009. The aerial parts of Salvia officinalis and Mentha piperita were harvested in summer, when the plants were in their full blooming stage and dried in the shade. The essential oil of the aerial parts was extracted by hydrodistillation and was analyzed by capillary GC and GC/MS method. The micro-organisms employed in this study were: E. coli, S. aureus, S. enteritidis, L. monocytogenes. By employing disc diffusion and tube dilution methods, antimicrobial effects of the oils were studied. Antioxidative property, free radical scavenging capacity, and antimicrobial activities of the oils were also studied. Chemical analysis of the extracts resulted in the identification of 28 and 37 compounds in the essential oils of Salvia officinalis and Mentha piperita respectively. The sensitivity of the bacteria to the oils in order of decreasing the sensitivity was L. monocytogenes, E. coli, S. aureus, and S. enteritidis. The antibacterial properties of the essential oil from Mentha piperita leaves were higher than the oil of Salvia officinalis leaves. Also inhibitions zones of microbial growth were not correlated with the microbicidal kinetics of the oils. This study showed that the herbal essences of Salvia officinalis and Mentha piperita are very active against E. coli, S. aureus, S. enteritidis and L. monocytogenes

[Chemical composition and antibacterial activity of the essence oil of peppermint [mentha piperita L]]

Peppermint [Mentha piperita L.] is a perennial herbaceous essence oil bearing plant which belongs to the Lamiaceae family. This plant is a valuable and important herb which has many therapeutic properties. Recent investigations have shown its excellent anti-irritable bowel syndrome effects. Other properties of this plant are anti-inflammatory, analgesic, promote menstrual flow, antipyretic, antiseptic and anti-rheumatoid effects. This investigation was conducted to study the antibacterial properties of peppermint essence oil, as well as determining the content and composition of essential oil. In order to study the effect of the antibacterial activity of the essence oil of peppermint, this experimental study was conducted in 2009 at Hamedan University of Medical Sciences. The aerial parts of the peppermint were harvested in summer when it was in the full blooming stage of the plant. The collected aerial parts were then dried in the shade. The essence oil of the aerial parts was extracted by hydro-distillation technique using Clevenger apparatus and was analyzed by the capillary GC and GC/MS method. Anti bacterial properties of the essence oil on four pathogenic bacteria were determined by using broth dilution and well diffusion agar methods. The collected data were analyzed by the SPSS version 11.5 software, using the independent t-test. The essence oil of peppermint showed the maximum anti bacterial effect on E. coli and the minimum effect on S. aureus and P. aeuroginosa. The essence oil content of aerial parts was 0.69% [w/w] based on dry weight. The amount of menthol which is the main constituent of the oil and as an antiseptic component was 47.9%.Results of this study revealed that the essential oil of peppermint is rich in menthol and can be considered as an antibacterial agent in drug and food industries