Chemical Composition and Antibacterial Activity of Essential Oils of Two Species of Lamiaceae against Phytopathogenic Bacteria.

In this study, we aimed to determine chemical composition and antibacterial activities of Satureja hortensis and Calamintha nepeta against to 20 phytopathogenic bacteria causing serious crop loss. The essential oils of S. hortensis and C. nepeta were isolated by the hydrodistillation method and the chemical composition of the essential oils were analyzed by GC-MS. The antibacterial properties of the essential oils were evaluated against 20 phytopathogenic bacteria through Disc diffusion assay and micro dilution assay. The results revealed that the essential oils of S. hortensis and C. nepeta have significant antibacterial activity. Furthermore, the findings of the study are valuable for future investigations focusing on the alternative natural compounds to control plant diseases.

Isolation of a flavonoid, apigenin 7-O-glucoside, from Mentha longifolia (L.) Hudson subspecies longifolia and its genotoxic potency.

Mentha is a medicinal and aromatic plant belonging to the Lamiaceae family, which is widely used in food, flavor, cosmetic and pharmaceutical industries. Recently, it has been found that the use of Mentha as a pharmaceutical source is based on its phytochemical constituents that have far been identified as tannins, saponins, phenolic acids and flavonoids. This study was designed to evaluate the mutagenic and antimutagenic activities of apigenin 7-O-glucoside (A7G), a flavonoid isolated from Mentha longifolia (L.) Hudson subspecies longifolia (ML). The possible antimutagenic potential of A7G was examined against mutagens ethyl methanesulfonate and acridine in an eukaryotic cell system Saccharomyces cerevisiae and sodium azide in Salmonella typhimurium TA1535 and 9-aminoacridine in S. typhimurium TA1537. According to our findings, any concentrations of the A7G used did not show mutagenic activity but exerted strong antimutagenic activities at tested concentrations. The inhibition rates for the Ames test ranged from 27.2% (S. typhimurium TA1535: 0.4 µM/plate) to 91.1% (S. typhimurium TA1537: 0.2 µM/plate) and for the yeast deletion assay from 4% to 57.7%. This genotoxicological study suggests that a flavonoid from ML owing to antimutagenic properties is of great pharmacological importance and might be beneficial to industries producing food additives, cosmetics and pharmaceuticals products.

Genotoxic, antigenotoxic and antioxidant properties of methanol extracts obtained from Peltigera horizontalis and Peltigera praetextata.

Now-a-days, there is a big need to reduce genotoxic effects of mutagenic and carcinogenic agents in environment, which are increased by the technological development. Lichens produce a wide variety of unique metabolites due to being in various extreme areas and being symbiotic organisms of fungi and algae. Therefore, this study was planned to search new sources having antimutagenic activity by researching two different lichen species and to determine whether their usage is safe. With this respect, the mutagenic and antimutagenic properties of methanol extracts of the lichens were determined by the bacterial reverse mutation and sister chromatid exchange assays. Furthermore, the malondialdehyde level, superoxide dismutase, glutathione and glutathione peroxidase activities against aflatoxin B1 were determined for understanding the ways in which the lichens showed their genotoxic properties.

Determination of genotoxic and antigenotoxic properties of essential oil from Ferula orientalis L. using Ames/Salmonella and E. coli WP2 bacterial test systems.

The essential oils having many application fields such as medicine, flavoring, cosmetics are natural products obtained from aromatic plants. As the natural products of Ferula species have a wide range of use in folk medicine, this study was planned to evaluate the mutagenic and antimutagenic activities of essential oils of leaves and flowers of Ferula orientalis grown in Erzurum, through the bacterial reverse mutation assay. Furthermore, the chemical compositions of essential oils isolated by the hyrodistillation method were analysed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS), as their biological activities were connected to their contents. According to our results, any tested essential oil at any used concentration on Salmonella typhimurium TA1535 and TA1537 strains and in Escherichia coli WP2 uvrA strain showed no mutagenic activity. However, the tested materials at different concentrations showed antimutagenic activities against the used mutagens. The inhibition rates ranged against sodium azide (NaN3) on S. typhimurium TA1535 from 29% to 36%, against 9-aminoacridine (9-AA) on S. typhimurium TA1537 from 40% to 68% and against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on E. coli WP2 uvrA from 23% to 52%, respectively. Also, it is revealed by GC and GC/MS analysis of the essential oils isolated from the leaves and flowers, respectively. The major compounds in these oils were determined as α-cadinol, δ-cadinene and germacrene D-4-ol. The results of this study indicate that as the essential oils of F. orientalis have many constituents, they show no mutagenic activity but significant antimutagenic activity, and these materials can be safely used in medicinal applications after further investigations.

Determination of chemical composition and genotoxic effects of essential oil obtained from Nepeta nuda on Zea mays seedlings.

We aimed to determine the genotoxic potential of essential oil (EO) obtained from Nepeta nuda. The chemical content of EO was measured via gas chromatography/mass spectrometry. The most abundant contents were 4aα,7ß,7aα-nepetalactone (18.10%), germacrene (15.68%) and elemol (14.38%). For genotoxic effects of EO, Zea mays' seeds were exposed to four different concentrations of this oil. Inhibition of root and stem growth were observed with an increase in EO concentrations. Randomly amplified polymorphic DNA (RAPD) method was used to determine the genotoxic effects of EO. Some changes occurred in RAPD profiles of germinated EO-treated seeds. Even though total soluble protein quantity vary, the data observed from the protein profiles of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that there was a little differentiation between band profiles of treated samples and control group. We concluded that the basis of interactions between plants, like allelopathy, may be related with genotoxic effects of EO.

Isolation of some luteolin derivatives from Mentha longifolia (L.) Hudson subsp. longifolia and determination of their genotoxic potencies.

This study was designed to evaluate the mutagenic and antimutagenic activities of luteolin derivatives (luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide) isolated from Mentha longifolia (L.) Huds. subsp. longifolia by using Ames Salmonella test (TA 1535 and TA1537 strains). In the antimutagenicity assays, luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide showed antimutagenic effects on TA1537 and TA1535 strains. The highest inhibition rates for luteolin 7-O-glucoside, luteolin 7-O-rutinoside and luteolin 7-O-glucuronide on TA1537 strain were 84.03%, 87.63% and 67.77%, respectively. Similarly, in the antimutagenicity assays performed with the TA1535 strain, the inhibition rates for luteolin 7-O-glucoside and luteolin 7-O-rutinoside were 23.86% and 23.76% respectively. Our findings showed that the antimutagenic properties of luteolin derivatives on TA1537 and TA1535 strains have been found to be structure dependent. The clarification of differences in antimutagenic potency of these luteolin derivatives based on their structures has been demonstrated in this study.

Isolation of 3 flavonoids from Mentha longifolia (L.) Hudson subsp. longifolia and determination of their genotoxic potentials by using the E. coli WP2 test system.

UNLABELLED: Flavonoids, abundant in most of plant species, are widely used in medicine and development studies on phytotherapeutic drugs due to their various biological activities. In the present study, 3 flavonoids, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, and apigenin-7-O-glucuronide, were isolated from Mentha longifolia (L.) Hudson subsp. longifolia by using E. coli WP2 genotoxicity assay guided fractionation procedures. Later, the mutagenic and antimutagenic properties of each flavonoid were evaluated by using the same genotoxicity assay. The results showed that all the test compounds have significant antimutagenic activity at tested concentrations with or without S9 activation. The inhibition rates were between 25.3% (apigenin-7-O-glucoside with S9-2.0 µM/plate) and 59.0% (apigenin-7-O-rutinoside without S9-2.0 µM/plate). In conclusion, the results revealed that the 3 flavonoids from Mentha longifolia (L.) Hudson subsp. longifolia have significant antimutagenic activity, and the findings of the present study are valuable for further investigations, focus on the phytotherapeutic drug discovery. PRACTICAL APPLICATION: Apigenin derivatives can be thought as genetically safe at tested concentrations because they did not show mutagenic activity. Furthermore, they have also significant antimutagenic activity. These are valuable for further research focus on phytotherapeutic drug discovery and development.