Suzana Branković

Chemical composition and antimicrobial activity of Satureja hortensis L. essential oil

Essential oil of Satureja hortensis L. was analyzed by GC and GC/MS and tested by a broth micro-well dilution method for activity against multiresistant clinical isolates of pathogenic bacteria from 10 different genera: Klebsiella, Escherichia, Proteus, Staphylococcus, Streptococcus, Pseudomonas, Enterococcus, Enterobacter, Citrobacter and Acinetobacter. The main compounds in the oil were carvacrol (67%), γ-terpinene (15.3%) and p-cymene (6.73%). The oil showed activity against all tested strains. MIC/MBC values were in the range of 0.78-25 μl/ml, with the exception of the strain P. aeruginosa. Microbicidal concentration for this particular strain (50 μl/ml) was the highest tested concentration. The oil showed inhibitory and bactericidal effect at the same concentration (MIC=MBC) for all but three strains.

Comparison of the Hypotensive and Bradycardic Activity of Ginkgo, Garlic, and Onion Extracts

The acute effect of ethanol extracts ginkgo (Ginkgo biloba L.), garlic (Allium sativum L.), and onion (Allium cepa L.) on arterial blood pressure (BP), and heart rate (HR) in anesthetized normotensive rats was examined and compared. Arterial BP was registered in the left carotid artery. The data showed that intravenous administration of the extracts produced dose-dependent and reversible hypotensive and bradycardic effects. The most effective in reducing arterial BP and HR is extract of garlic. There were statistically significant differences in bradycardic and hypotensive effects of the garlic and ginkgo extracts.

Effects of Mistletoe (Viscum Album L., Loranthaceae) Extracts on Arterial Blood Pressure in Rats Treated with Atropine Sulfate and Hexocycline

Acute effects of different extracts of mistletoe stem (Viscum album) were investigated on values of arterial blood pressure in Wistar rats. Arterial blood pressure was registered by direct method in the left carotid artery and the investigated extracts (total ethanol, ether and ethyl acetate) of mistletoe stem were administered into the right jugular vein. The total ethanol extract exhibited the best effect even on the lowest applied concentration (3.33 × 10−5 mg kg−1) and significantly decreased the blood pressure after applied concentration 1.00 × 10−3 mg kg−1. On the contrary, the ether and ethyl acetate extracts exhibited notable activity only by higher administered doses. Atropine as a nonselective blocker of muscarinic receptors reduced the hypotensive effects of ethanol extract of mistletoe. Hexocycline, a selective blocker of muscarine receptors, significantly raised blood pressure and decreased the hypotensive effect of ethanol extract of mistletoe on arterial blood pressure in rats.

Comparative Study of Spasmolytic Properties, Antioxidant Activity and Phenolic Content of Arbutus unedo from Montenegro and Greece

Arbutus unedo leaf is used traditionally for gastrointestinal complaints. Ethanol extracts from Arbutus unedo collected in both Montenegro (AuM) and Greece (AuG) were found to decrease the ileal basal tonus, with AuG producing a significantly higher (p < 0.05) reduction in contractile response to acetylcholine. AuM and AuG relaxed 80 mm K+ induced contractions and shifted the Ca++ concentration–response curves to the right, similar to that caused by verapamil, suggesting that the spasmolytic effect was induced through calcium channel inhibition. The antioxidant activity of AuM and AuG and the phenolic content of the extracts and dry plant material were studied, and both extracts were found to possess considerable antioxidant properties. AuG showed a stronger in vitro antioxidative activity in the DPPH assay and in the TBA test. Polyphenol, tannin and flavonoid levels were higher in AuG, supporting the more potent spasmolytic and antioxidative effects, whereas the arbutin content was higher in dry plant material collected in Montenegro. Copyright

Relaxant Effect of the Ethanol Extract of Helichrysum plicatum (Asteraceae) on Isolated Rat Ileum Contractions

Helichrysum plicatum (Turkish Helichrysum) has been used in folk medicine for the treatment of gastric and hepatic disorders. The aim of the present study was to examine the relaxant activity of an extract of H. plicatum flowers on isolated rat ileum. Segments of ileum of rats were suspended in an organ bath. Cumulative concentrations of H. plicatum ethanol extract induced a relaxant effect on spontaneous rat ileum contractions. H. plicatum extract caused a mean contractile response of 81.68 ± 6.17% (at a dose of 0.01 mg/mL) and 30.08 ± 9.07% (at a dose of 1 mg/mL). A similar effect was observed with papaverine (0.01–3 μg/mL). H. plicatum extract (0.01–1 mg/mL) relaxed high K+ (80 mM) precontractions, an effect similar to that caused by papaverine (0.01–3 μg/mL). The plant extract (0.03–0.3 mg/mL) also induced a significant depression of the cumulative concentration response curve for acetylcholine (5–1500 nM) (p < 0.01). Atropine (140 nM) abolished the acetylcholine effect. The extract (0.03–0.3 mg/mL) reduced the histamine (1–300 nM) and BaCl2 (3–900 μM) induced contractions (p < 0.01). Our results showed the relaxant effect of the ethanol extract of Helichrysum plicatum flowers on the isolated rat intestine Extract of H. plicatum can inhibit the spontaneous ileum contractions and contractions induced by acetylcholine, histamine, barium and potassium ions.

Chloroform extract of underground parts of Ferula heuffelii: secondary metabolites and spasmolytic activity.

Plants from the genus Ferula L. (Apiaceae) were used for various purposes in traditional medicine of different nations throughout the history. Ferula heuffelii Griseb. ex Heuffel is a perennial species endemic for Balkan peninsula. Ten compounds which belong to classes of prenyl‐furocoumarin‐, prenyl‐dihydrofurochromone‐, prenyl‐benzoyl‐ and prenyl‐benzoylfuranone‐type sesquiterpenoids, as well as sesquiterpene coumarins and phenylpropanoids, were, for the first time, isolated from the CHCl3 extract of the underground parts of this plant and identified. Furthermore, extract and three isolated compounds, i.e., latifolone (1), dshamirone (4), and (2S*,3R*)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dien‐1‐yl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethylfuro[3,2‐c]coumarin (6) were, for the first time, evaluated for their in vitro antispasmodic activities in three experimental models: spontaneous contraction, and ACh‐ and KCl‐induced contraction of an isolated rat ileum. The extract (0.1–1.3 mg/ml) and compound 6 (1–10 μg/ml) exhibited dose‐dependent effect in all three models. Compound 1 (1–6 μg/ml) affected spontaneous contractions and those induced by KCl, while compound 4 (8 μg/ml) displayed only moderate activity with ACh‐induced contractions. It can be concluded that tested compounds contribute to exhibited antispasmodic activity of crude extract. Additionally, extract (0.1–1.3 mg/ml) was tested for in vitro relaxant activity on an isolated rat trachea, and relaxed the KCl‐induced contractions in a dose‐dependent manner.

The role of essential oils and the biological detoxification in the prevention of aflatoxin borne diseases.

Fungi are an important group of microorganisms. They are studied due to their significant impact on the environment, industry and human health. In relation to biological aspects, biogeochemical cycling of elements, the world of nature would not be possible without the contribution of fungi as the primary decomposers of organic material. On the other hand, food decay by the fungi spoilage causes considerable economic losses and constitutes a health risk for consumers due to the potential of fungi to produce mycotoxins. Mycotoxins are chemically diverse secondary metabolites that can be harmful both to animal and human health. Aflatoxins, a widely studied group of toxins among mycotoxins, are mainly biosynthesized by Aspergillus flavus and Aspergillus parasiticus. Therefore, the control of fungi and the production of aflatoxins, especially the most toxic aflatoxins B1 and G1, is essential and decisive. Over the last few decades, numerous studies have demonstrated that plants, especially their essential oils, contain diverse bioactive components that can protect crops from becoming contaminated by different mold species, Aspergillus in particular, with an emphasis on A. flavus and A. parasiticus; as well as that, they can prevent the contamination of food produce during the processing and storage and prevent the production of aflatoxins. Plant essential oils are expected to be more advantageous than synthetic compounds because of their relatively safe status, easy decomposition, environmentally friendly and non-phytotoxic properties. This paper also presents the recent research in biological control of aflatoxin contamination.

Effects of Extracts of Ginkgo, Onion, and Celery on the Contractility of Isolated Rat Atria

The acute negative inotropic and chronotropic effects of the commercial extract of ginkgo leaf (Gingium®) and ethanolic extracts of onion bulbs and celery root on spontaneous and noradrenalin-stimulated contractions of the Wistar rat atria were investigated. All analyzed extracts exerted negative inotropic effects on the isolated rat atria. Among the tested extracts, the extract of ginkgo showed the strongest negative inotropic effects on rat atria, either in spontaneous or noradrenalin-induced contractions, being more potent than the onion and celery extracts, respectively.

Inhibitory effect of aqueous and ethanolic garlic (Allium sativum L., Lilliaceae) extracts on the rat atria.

The acute negative inotropic and chronotrophic effects of aqueous and alcoholic garlic extracts (Allium sativum L.) on spontaneous and adrenalin-stimulated contractions of the Wistar rat atria were investigated. The addition of garlic extracts to isolated rat atria evoked negative inotropic and chronotropic effects. Ethanolic garlic extract exerts much stronger negative inotropic (58.33 ± 14.76%) effects than aqueous extract (43.66 ± 16.32%). The difference in frequency reduction is especially conspicuous. Aqueous garlic extract very slightly affects the frequency, while ethanolic extract reduces it by more than 40%. In addition to these effects, the positive inotropism and chronotropism induced by the addition of noradrenaline, were much more antagonized by ethanolic garlic extract than by aqueous extract. Moreover, ethanolic garlic extract establishes sinus rhythm in the atria with extrasystoles induced by noradrenaline.

Antispasmodic Effect of Black Currant (Ribes nigrum L.) Juice and its Potential Use as Functional Food in Gastrointestinal Disorders

Objective: The purpose of this study was to investigate the relaxative effects of blackcurrant juice on the gastrointestinal smooth muscle in vitro. Materials and Methods: Berries of the blackcurrant cultivar Ometa were used for the preparation of the juice used. The spasmolytic activity of blackcurrant juice was tested on rat ileum isolated from male Wistar rats by monitoring its influence on spontaneous contractions, as well as contractions induced by potassium chloride (KCl), barium chloride (BaCl2), calcium chloride (CaCl2), and acetylcholine (Ach). The results are expressed as the mean ± standard deviation obtained in 6 measurements and statistical significance was determined by the Student t test, with p < 0.05 taken as significant. Results: The blackcurrant cultivar Ometa significantly reduced the frequency and the amplitude of spontaneous contractions (57.94 ± 3.44%) and Ach-induced contractions (42.74 ± 5.36%; p < 0.05) of the isolated rat ileum. Cumulative concentrations (0.01–3 mg/mL) of the Ometa juice also reduced contractions of the isolated rat ileum stimulated by KCl (51.46 ± 6.87%), CaCl2 (57.54 ± 6.47%), and BaCl2 (58.54 ± 10.55%). The inhibitory effects of the juice were proportional to the applied concentration. Conclusion: The antispasmodic effect of Ometa cultivar shows that common gastrointestinal disorders could be treated by the functional food.