Journal of Medicinal Plants and By-products
Volume:2 Issue: 2, Winter and Spring 2013

Many food products are perishable by nature and require protection from spoilage during their preparation, storage and distribution to give them desired shelf-life. Because food products are now often sold in areas of the world far distant from their production sites, the need for extended safe shelf-life for these products has also expanded. Currently, there is a strong debate about the safety aspects of chemical preservatives since they are considered responsible for many carcinogenic and teratogenic attributes as well as residual toxicity. For these reasons, consumers tend to be suspicious of chemical additives and thus the demand for natural and socially more acceptable preservatives has been intensified. One such possibility is the use of essential oils (EOs) as antibacterial additives. In the production of food it is crucial that proper measures are taken to ensure the safety and stability of the product during its whole shelf-life. In particular, modern consumer trends and food legislation have made the successful attainment of this objective much more of a challenge to the food industry. EOs comprise a large number of components and it is likely that their mode of action involves several targets in the bacterial cell. It is most likely that their antibacterial activity is not attributable to one specific mechanism but that there are several targets in the cell. The potency of naturally occurring antimicrobial agents or extracts from plants, ranges of microbial susceptibility and factors influencing antimicrobial action and their antioxidativeproperties, aimed at food preservation, are reviewed in this article. Methods employed for estimation of inhibitory activity, mode of action and synergistic and antagonistic effects are evaluated. Hence, it is recommended that more safety studies be carried out before EOs are more widely used or at greater concentrations in foods that at present. There is therefore scope for new methods of making food safe which have a natural or ‘green’ image.

The composition of essential oil isolated from Achillea eriophora, Achillea millefolium, Achillea biebersteinii and Achillea tenuifolia growing wild in the south west of Iran, was analyzed. A. eriophora, A. millefolium and A. tenuifolia essential oils were characterized by sabinene, 1, 8-cineole, terpinene-4-ol, ά bisabolol, p-Cymene, β-pinene and α-pinene. The A. biebersteinii essential oil was characterized by sabinene, borneol, camphor, piperitone and α-pinene. Antioxidant activity was analyzed using the 1,1-diphenyl-2- picrylhydrazyl free radical scavenging and Fe 3 reducing power methods. Results indicated essential oil obtained from A. eriophora, A. millefolium, A. tenuifolia and A. biebersteinii exhibited a dose-dependent increase with a radical scavenging effect of 85.0%, 82.0% , 82.0% and 64.0% at 350 μg/ml, which are close to the 1,1 diphenyl-2- picrylhydrazyl inhibition of the positive control Butylated Hydroxytoluene (88.0%) at the same concentration. It was shown that the A. biebersteinii essential oil exhibited the weakest antioxidant effect than Butylated Hydroxytoluene or other Achillea spp. essential oils. In this study chamazulene, ά-bisabolol and ά –bisabolol oxide percentage were higher in A. eriophora, A. millefolium and A. tenuifolia essential oil compared to A. biebersteinii essential oil and these compounds improved antioxidant capacity of Achillea spp.

Hairy root systems are formed by transforming plant tissues with the “natural genetic engineer” Agrobacteriumrhizogenes. In most plants such as Cichorium intybus L., hairy root cultures have proven to be an efficient system for secondary metabolites production. The effect of Zinc (ZnSO4), a heavy metal, was investigated at different concentrations (0, 1, 5 and 10 mM) on some secondary metabolite contents at three time course levels (24, 48 and 72 h).The treated hairy roots of chicory were compared with control and with each other in growth rate, phenol flavonoid and chicoric acid production rate. In addition, antioxidant enzyme activities were determined. Results showed decreased hairy roots weights and increased phenol, flavonoid, chicoric acid and antioxidant enzyme activities in response to higher concentrations of Zinc at higher time courses. Also, an increase in chicoric acid release into the culture media was observed that is important for industrial uses.

Medicinal plante Borazambol with the scientific name of Perovskia abrotanoides Karel. belongs to the family Lamiaceae. It is growing wild in the margin of mountainous roads of arid and cold climate of north Iran. It is for a long time that indigenous people by different methods in traditional medicine use its products in preventing and curing diseases. In this research, essential oils of Perovskia abrotanoides Karel, extracted and measured at the time of flowering stage and vegetative stage by different methods of distillation and then were analyzed by GC and GC/MS. The essential oil yield at vegetative stage with hydro-distillation was 2.2 , water & steam distillation (Kyzer & Long) 5.7% and steam distillation 2.5%, respectively. Major component identificated by water distillation (Clavanger) were α- terpineol (32%), n-octanol (22.5%), myrcene 7.2%), and by water and water & steam distillation (Kyzer & Long) were α- terpineol (30.3%), n-octanol (20.1%), myrcene (7.2%), and by steam distillation were α- terpineol (26.2%), n-octanol (17.4%), n-pentadecane 8.2%). The essential oil yield at flowering stage with hydro-distillation was 1.9%, water & steam distillation (Kyzer & Long) 1.5% and steam distillation 1%, respectively. Major component identificated by water distillation (Clavanger) were n-octanol (23.3%); α- terpineol (21.9%) and (Z)-β- ocimene (15.5%), and by water and steam distillation (Kyzer & Long) were α- terpineol (19.9%), n-octanol (19.9%), (Z)-β- ocimene (13.6%), and by steam distillation were n-octanol (16.6%), α- terpineol (15.3%), and (Z)-β- ocimene (13.5%).

Thyme (Thymus vulgaris L.) is an important medicinal plant with highly valuable essential oils. In this study, effects of different fertilizer treatments and cuts on Thymus vulgaris L. was evaluated in 2008-2009. The research was conducted at Alborz Research Station, Research Institute of Forests and Rangelands, Karaj, Iran. The Experimental design was split plot in time in the form of a randomized complete block design with three replications. The main factor was nutrition in 16 levels consisting of different combinations of nitrogen (N), phosphorus (P), potassium (K) and manure (M): N0P0K0M0, N40P32K40M0, N80P64K80 0, N120P96K120M0, N160P128K160M0, N140P112K140M5, N120P96K120M10, N100P80K100M15, N80P64 80M20, N60P48K60M25, N40P32K40M30, N20P16K20M35, N0P0K0M40, N0P0K0M30, N0P0K0M20 and N0P0K0M10 (indices following the letters N, P and K are application rates in kg/ha, indices following the letter M are the application rates of manure in t/ha). The sub factor was harvest (cut) time (late May and early September). Results indicated that fertilizer, harvest date and their interactions significantly affected most of the traits. Mean comparison of the interactions indicated that treatments containing both chemical fertilizers and manure showed positive effects, although the most plant height was achieved with N160P128K160M0 × 1st cut, in both years (32.5 cm in 2008 and 32.66 cm in 2009). Essential oil yield was the highest in 2008 in N120P96K120M10 × 2nd cut (26.01 kg/ha), and in 2009 in N100P80K100M15 × 1st cut (26.79 kg/ha). Generally, it can be concluded from the results that T. vulgaris responds well to fertilization, and selecting the best treatment depends on the objective of production.

Evaluation of essential oil yield, morphological and phenological traits of seven populations of two Chamomile species (Matricaria aurea and M. recutita), were carried out using Randomized Completely Blocks Design(RCBD) in three replications in Alborz research station in Karaj, Iran during 2011-2012. Data were collected for 12 morphological and phenological traits. Analysis of variance showed significance difference (P ≤%1) between populations for all of traits. Also the effect of year and year x population interaction effect were significant (P≤%1) for all of traits. Results showed Matricaria recutita hah higher values for all of traits except shoot fresh and dry weight. Mean comparison showed that two populations of Esphahan and Hamadan from Matricaria recutita and one population Gachsaran of Matricaria aurea had high shoot yield and essential oil yield than other populations. Result of simple correlation analysis showed that essential oil percentage was positively correlated with plant height, flower number, shoot dry weight and essential oil yield andnegatively correlated with time of flowering and maturity date and GDD (Growth Degree Days), suggesting that early maturity plants had higher essential oil content. Results of stepwise regression analysis for essential oil content as dependant variables and other traits as independent variables showed significant effects of maturity date, flower number , plant height, canopy diameter length and flowering date in essential oil content.

A study was conducted to investigate the effect of different planting densities and nitrogen doses on essential oil content and yield in herb and leaves of basil (Ocimum basilicum L.). The research was conducted during 2007 and 2008 using split-plot randomized complete block design with four replications. The experiment consisted of fourplant densities (30×20, 40×20 and 50×20 cm) as the main plot and four nitrogen levels 0, 50, 100 and 150 kg/ha) as the sub plots. Results showed plant density did not have significant effect on essential oil content and essential oil yield in herb and leaves. Mean essential oil ratio in herb was 0.49, 0.44%; essential oil ratio in leaf 0.59, 0.54%; essential oil yield in herb 19.4, 23.7 l/ha and essential oil yield in leaf was 12.8, 16.1 l/ha during 2007 and 2008, respectively. The highest essential oil ratio in herb was obtained from 40×20 cm plant density and 50 kg ha-1 N during 2007. Nitrogen fertilizer had statistically insignificant effect on oil ratio of herb and leaves during two years of experiment. The highest essential oil yield of herb was obtained from low density (30 20 cm) using 100 kg ha-1 N fertilizer. In General, essential oil yield during 2008 with three cuts was better compared to 2007 with two cuts.

Lisianthus (Eustoma grandiflorum cv. ‘Mriachii Blue’) is one of the most important and marketable cut flowers in the world. However, a relatively limited vase life reduces its marketability. The aim of the present study was to evaluate the effects of essential oils in extending vase life of cut flowers of Lisianthus. For this purpose a factorial experiment based on a completely randomized design with Zataria multiflora and Echinophora platyloba essential oils at (0, 100, 200 ppm) with 3 replications, was conducted. The results showed that addition of essential oils to vase solutions increased vase life, petal water content, leaf relative water content and SPAD value, significantly. The highest vase life (14.5 days) was observed in the vase solution containing 200 ppm E. platyloba plus 100 ppm Z. multiflora essential oils with 95% increase as compared to the control. All essential oil treatments resulted in higher relative fresh weight as compared to the control; however the highest relative fresh weight was observed in cut flowers treated with E. platyloba essential oil at 200 ppm with 54% increase over the control. It can be safely concluded that essential oils as natural, safe and biodegradable compounds are suitable alternatives to conventional chemical treatments in order to prolong vase life of cut flowers of Lisianthus.

This study was conducted to investigate allelopathic effect of the essential oil of Artemisia herba-alba Asso., on seed germination characteristics of Agropyron desertorum and Agropyron cristatum in a laboratory experiment. Essential oil was extracted from the aerial parts of Artemisia herba-alba using a Clevenger Type apparatus. The volatile chemical compositions of Artemesia herba-alba were determined with gas chromatography–mass spectrometry (GC–MS). The crude essential oil was diluted with ethanol to a final concentration of 100 ppm, 500 ppm, 1000 ppm, 1500 ppm and 2000 ppm. Seed germination test was carried out on filter paper moistened with 5 ml of different dilutions of essential oil or distilled water as control. The results showed that increase in essential oil concentration reduced root lengths, seed germination percentage and vigor index of Agropyron desertorum and Agropyron cristatum.

Zinc and iron nano-oxides (100 ppb) were promoted the hypericin and hyperforin production in Hypericum perforatum cell suspension culture. High performance liquid chromatography method was used for detectection and identification of hypericin and hyperforin in H. perfuratum cell suspension cultures elicited with different concentrations of zinc and iron nano-oxide (0, 50, 100 and 150 ppb) after 72 h. In the cultures stimulated by zinc nano-oxide, the hypericin and hyperforin production reached to the maximum (7.87 and 217.45 μg/g DW, respectively), which were 3 and 13-fold higher than the control. The amount of hypericin and hyperforin was increased from 2.07 and 16.27 μg/g DW to 11.18 and 195.62 μg/g DW in iron nano oxide treated cultures. The cell cultures treated with zinc and iron nano-oxides showed increased hyperforin production as compared to the hypericin production. These observations suggested that nano-particles can be appropriate candidates for elicitation studies of in vitro secondary metabolites production.

There is substantial diversity in Achillea biebersteinii plants in Iran. It has considerable different biological activities including antibacterial, antifungal, antioxidant, insecticidal, herbicidal and wound healing. Research improvement for medicinal plants depends on the available genetic diversity. The assessment of genetic variability could increase the information for breeding programs. To evaluate possible diversity among different populations of A. biebersteinii, agro-morphological and germination traits of the populations were investigated. To evaluate agro-morphological traits, seeds of 22 populations were sown in the field. The experiment was laid out using Randomized Complete Block Design (RCBD) with three replications. A total of six agromorphological traits including plant height, plant diameter, lateral shoot number, flower diameter, flower number and shoot yield, were collected. For evaluation of seed germination traits, seeds of 10 populations were sown in standard condition ((20±2 °C) and pre-cold treatment (7 days at 4 °C followed by standard condition). The seed germination traits were studied as hypocotyl length, radicle length, radicle to hypocotyl length ratio, seedling length, germination percentage, germination rate and vigor index. Based on the results the population 20187 (Golestan) had the highest value for all of agro-morphological traits. For germination traits the populations 10140 (Minoodasht) and 17310 (Shahrood) were the best performing populations. The result showed that pre cold treatment reduced radicle length in most cases but population 17310 (Shahrood) produced significantly longer radicle under pre-cold treatment. This population was recommended for dry cold regions.

Heavy metal pollution is a worldwide problem with serious environmental consequences. The objective of the present experiment was to investigate whether arginine as nitric oxide precursor and or polyamines substrate can decrease the destructive effects of oxidative stress induced by nickel contamination in Hyoscyamus niger plant. In this study the effects of arginine pretreatment on alkaloid content of Hyoscyamus plant under heavy metal stress were investigated. In this research, four weeks seedlings were pretreated with 10 or 20 μmol arginine and then subjected to 50 or 100 μmol Ni solutions. Results showed that hydrogen peroxide content, lipoxigenase, catalase and guaiacol peroxidase activity increased in those plants which were under Ni stress, while ascorbate peroxidase activity did not change. Alkaloids content decreased in Ni stressed plants. Arginine pretreatment decreased the amounts of hydrogen peroxide and activity of these enzymes in stressed plants when compared with non-pretreated plants. Proline content also increased in Ni-stressed plants while arginine pretreatment decreased the proline content. Pretreatment of plants with arginine increased the amounts of total alkaloids in plants which were under Ni stress. In this study, it seems that protective effects of arginine were related to either polyamines or indirect synthesis of NO from polyamines.

In this study, aerial parts of Lippia citriodora Kunth were harvested at three phenological stages (i.e. vegetative, full flowering and fruit set). The essential oil isolated by hydro distillation for 3 h using a Clevenger-type apparatus and the oil was analyzed by GC and GC-MS. The yields of oils (w/w%) in different stages was in the order of: full flowering (0.9%), vegetative (0.48%) and fruit set (0. 25%). In total, 13, 12 and 11 compounds of essential oil were identified in vegetative, full flowering and fruit set, respectively. The main compounds in three stages were geranial and neral. Geranial was highest at vegetative (33.7%) and lowest at full flowering 32.7%) stages. The highest and lowest neral content was observed at vegetative (26.1%) and fruit set (25.06%) stages, respectively.

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