Dragana Vučićević

Quercetin Ameliorates Experimental Autoimmune Myocarditis in Rats

PURPOSE Experimental autoimmune myocarditis (EAM) in rats is an animal model of human giant cell myocarditis and post-myocarditis dilated cardiomyopathy. The pathogenesis of EAM has not been elucidated, but there is accumulating evidence that cytokines secreted from monocytes/macrophages and T cells play a crucial role in the induction and progression of disease. Flavonoids are a large group of polyphenolic compounds abundantly present in the human diet, which scavenge oxygen radicals and have anti-inflammatory activities. Having in mind in vivo beneficial effects of flavonoid quercetin in different animal models of immunoinflammatory diseases such as experimental autoimmune encephalomyelitis and adjuvant arthritis, on the one side, and its in vitro suppressive effect on production of tumor necrosis factor-alpha (TNF-α) on the other side, we investigated the effects of quercetin on EAM in rats. METHODS Myocarditis was induced in Dark Agouti (DA) rats by injection of porcine cardiac myosin and quercetin at doses of 10 or 20 mg/kg was orally administered from days 0 to 21 after induction of disease. The severity of myocarditis was evaluated by determination of heart weight/body weight ratio (Hw/Bw) and histopathological examination of hearts. The levels of cytokines (TNF-α, IL-12, IL-17 and IL-10) in serum and lymph node cells (LNC) culture supernatants were measured by ELISA. RESULTS The rats treated with 20 mg/kg of quercetin had significantly decreased incidence of EAM, Hw/Bw, macroscopic and microscopic scores of hearts. Further, in EAM rats treated with quercetin levels of TNF-α and IL-17 were significantly lower, while the level of IL-10 was significantly higher both in serum and culture supernatants of LNC stimulated with concanavalin A compared with vehicle-treated animals. CONCLUSIONS The present study suggests that quercetin ameliorates EAM, at least in part, by interfering production of proinflammatory (TNF-α and IL-17) and/or anti-inflammatory (IL-10) cytokines.

Chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil

This paper presents the results of a study on chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil from Vojvodina province (north of Serbia). The investigated oil was hydrodistilled from a flowering plant and analysed by GC and GC-MS. Fifty-three constituents were identified (>97% of total oil), with geranial (41.42%, w/w) and neral (29.61%, w/w) as the most prominent. The antimicrobial activity of the oil was evaluated using agar disc diffusion and broth microdilution method against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, two strains of Klebsiella pneumoniae and two strains of Candida albicans. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. Pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. Albicans (MIC = 50 µ/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. Pneumoniae (MIC = 200 µ/ml), while E. faecalis and the other strain of K. Pneumoniae expressed a higher degree of resistance (MIC > 200 µ/ml). This study confirms that essential oil of T. pannonicus possesses remarkable in vitro antimicrobial activity against several medicinally important pathogens. This is attributable to lemon-scented citral, a mixture of geranial and neral, which has well-documented antimicrobial activity against a range of bacteria and fungi.

Antimicrobial and antioxidant properties of methanol extracts of two Athamanta turbith subspecies

The methanol extracts of fruits and leaves of Athamanta turbith subsp. hungarica (Borbás) Tutin (Umbelliferae) and A. turbith subsp. haynaldii (Borbás & Uechtr.) Tutin were analyzed for their antimicrobial and antioxidant properties. Phenolic compounds (flavonoids and phenolic acids) of the extracts were examined using HPLC. All the extracts were characterized by the presence of caffeic acid derivates, luteolin and its glycosides, with luteolin 7-O-glucoside as one of the main compounds. Luteolin 7-O-rutinoside was detected only in A. turbith subsp. haynaldii extracts. Investigation of antimicrobial activity was performed against six bacteria and two fungal strains, using the agar diffusion technique and broth microdilution assay. The extracts of investigated A. turbith subspecies exerted similar antimicrobial activity, whereas the best activity was detected against Candida albicans. In order to investigate antioxidant properties, ferric ion reducing antioxidant power (FRAP), radical scavenging capacity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (HO·), and the effect on lipid peroxidation (LP) were examined. All the examined extracts showed moderate antioxidant capacity, whereas the fruit extracts were more active than the extracts of leaves. Also, the extracts of A. turbith subsp. hungarica exerted higher antioxidant capacity than corresponding A. turbith subsp. haynaldii extracts. The relationship between estimated activity and chemical composition of the extracts is discussed.

Beneficial Effects of Dimethyl Fumarate on Experimental Autoimmune Myocarditis

BACKGROUND Fumaric acid esters (FAE) have been proven to be effective for the systemic treatment of psoriasis and multiple sclerosis, Th1 cell-mediated chronic inflammatory diseases, but their effect on autoimmune myocarditis has not yet been addressed. We investigated the effect of dimethyl fumarate (DMF) on myosin-induced experimental autoimmune myocarditis (EAM). METHODS Dark Agouti (DA) rats immunized with porcine cardiac myosin were orally treated with 5 and 15 mg/kg body weight (bw) DMF either from days 0-10 (early treatment groups) or from days 10-21 (late treatment groups) after induction of EAM. All rats were sacrificed on day 21 after immunization and hearts were evaluated macroscopically and microscopically. Levels of TNF-alpha and IL-10 in serum and lymph node cells culture supernatants were detected by ELISA. RESULTS Both early and late treatment with 15 mg/kg body weight (bw) DMF markedly reduced the severity of myocarditis by comparing the incidence, heart weight/bw ratio, macroscopic and microscopic scores, and number of OX-6+ cells in the myocardium. Further, levels of tumor necrosis factor-alpha (TNF-alpha) in serum and culture supernatants of lymph node cells stimulated with ConA or myosin were significantly lower in DMF-treated EAM animals compared with vehicle-treated EAM rats. There was no significant difference in serum levels of interleukin-10 between DMF- and vehicle-treated EAM rats. CONCLUSIONS These results show for the first time that DMF ameliorates experimental autoimmune myocarditis and may be acted, at least in part, by interfering with the production of TNF-alpha.

Comparative effects of aspirin and NO-releasing aspirins on differentiation, maturation and function of human monocyte-derived dendritic cells in vitro.

Acetylsalicilyc acid (aspirin, ASA) is a well known anti-inflammatory drug with immunomodulatory properties. NO-releasing aspirins (NO-ASA) are new compounds with anti-inflammatory properties. We studied the effects of ASA and two NO-ASA (NCX 4016 and NCX 4040) on human monocyte-derived dendritic cells (MoDC). Immature MoDC were generated in vitro from monocytes in the presence of recombinant human granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4. Mature MoDC were obtained by adding lipopolysaccharide (LPS) in cultures of immature MoDC. As we found that ASA at 4-8 mM, NCX 4016 at 400-800 microM and NCX 4040 at 4-8 microM stimulated apoptosis of monocytes and immature MoDC, sub-apoptotic concentrations of ASA (2 mM), NCX 4016 (200 microM) and NCX 4040 (2 microM) were used in experiments. Examined substances were added at the beginning of MoDC cultivation. MoDC differentiated in the presence of examined compounds had lower expression of HLA-DR, CD80, CD40 and CD54, decreased allostimulatory activity and lower production of IL-12 p40. ASA and NCX 4016 decreased production of IL-10, whereas NCX 4040 had the opposite effect. ASA inhibited the expression of CD1a and prevented downregulation of CD14, NCX 4016 stimulated the differentiation of CD1a+CD14+ and CD1a(-)CD14+ cells, whereas NCX 4040 decreased the proportion of CD1a+CD14(-) and increased the frequency of CD1a+CD14+ cells, compared to control. Maturation, both in ASA and NO-ASA treated MoDC was characterized by decreased allostimulatory activity, lower expression of CD83, HLA-DR, costimulatory molecules and CD54 and decreased production of IL-10 and IL-12 p40. In conclusion, we confirmed that ASA impairs differentiation, maturation and function of MoDC and found that NCX 4016 and NCX 4040 exerted similar, but not identical effects at about 10- and 1000-fold lower concentrations, respectively, compared to ASA.

Composition and Antimicrobial Activity of Salvia amplexicaulis Lam. Essential Oil

Abstract The chemical analysis of the Salvia amplexicaulis Lam. herb essential oil was performed using GC-FID and GC/MS. Fifty-one compounds (90.2% of the total oil) were identified. The oil was characterized by a high amount of sesquiterpenes (81.1%), with germacrene D (14.8%), viridiflorol (10.6%), caryophyllene oxide (10.5%), and β-caryophyllene (9.4%) being the main components. The microbial growth inhibitory properties of the oil was determined against Gram-positive bacteria Staphylococcus aureus, St. epidermidis, Micrococcus luteus Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli and a yeast Candida albicans. The best inhibitory effect was detected against M. luteus followed by the effects against St. epidermidis, St. aureus and C. albicans. Tested Gram-negative bacteria were more resistant than Gram-positive bacteria and C. albicans.

Composition and Antimicrobial Activity of Achillea coarctata Essential Oils from Greece

Abstract The essential oils of the inflorescences and leaves of Achillea coarctata Poir. (Compositae) growing spontaneous in Greece were obtained through hydrodistillation and analysed by GC-FID and GC-MS. Both oils were characterized by the abundance of oxygenated monoterpenes with 1,8-cineole (26.9 %and 29.1 %, respectively), camphor (22.1 %, 9.2 %) and borneol (5.0 %, 6.8 %) being the major constituents. Their in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria strains and the yeast Candida albicans was determined.

Composition and Antimicrobial Activity of the Rhizome Essential Oils of Two Athamanta turbith Subspecies

Abstract The hydrodistilled essential oils of the rhizomes of Athamanta turbith subsp. hungarica and A. turbith subsp. haynaldii were analyzed by GC-FID and GC/MS. Twenty-one compounds (99.8% of total oil) were identified in the oil from A. turbith subsp. hungarica, and 33 components (99.9% of total oil) were identified in the oil from A. turbith subsp. haynaldii. Both oils were characterized by high amounts of phenylpropanes, with myristicin (54.2% and 22.3%, respectively) and apiole (32.6% and 48.5%, respectively) being the main components. The antimicrobial activity of the oils was determined using the agar diffusion and broth microdilution method. Investigated essential oils were the most effective against Micrococcus luteus and Klebsiella pneumoniae, and had no effect against Pseudomonas aeruginosa. As for antifungal activity, essential oils exerted similar and significant activity, but only in higher concentrations.

Composition and Antimicrobial Activity of Essential Oils From Flower and Leaf of Laserpitium zernyi Hayek

Abstract The hydrodistilled essential oils of the flowers and leaves of Laserpitium zernyi Hayek were analyzed by GC-FID and GC/MS. Fifty-five compounds were identified in the flower oil (96.8% of total oil) and 58 in the leaf oil (89.4% of total oil). Both oils were characterised by the high amount of monoterpenes (59.1–75.6%), whereas sesquiterpenes were present in smaller quantity (21.2–29.2%). The main compounds in the flower oil were sabinene (18.5%), limonene (12.0%), P-phellandrene (12.0%) and terpinen-4-ol (10.6%), while in the leaf oil the most dominant were P-pinene (20.0%) and terpinen-4-ol (12.0%). The antimicrobial activity of the oils was determined using the agar diffusion and broth microdilution method against bacteria Staphylococcus aureus, St. epidermidis, Micrococcus luteus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli and a yeast Candida albicans. The best inhibitory effect (MIC 0.6 mg/mL) was exhibited by the flower oil against St. epidermidis, K. pneumoniae and C. albicans, the leaf oil against M. luteus, and both oils against E. coli.

COMPOSITION AND ANTIMICROBIAL ACTIVITY OF THE FRUIT ESSENTIAL OILS OF TWO Athamanta turbith SUBSPECIES

Athamanta turbith (L.) Brot. (Umbelliferae) inhabits limestone rock crevices in the mountains and gorges of southeastern Europe (Italy, the Balkans, and the Carpathians). It is currently considered to contain three subspecies: A. turbith ssp. turbith, A. turbith ssp. hungarica (Borbas) Tutin, and A. turbith ssp. haynaldii (Borbas & Uechtr.) Tutin [1]. In the Flora of FR Serbia, A. turbith ssp. hungarica is registered as the species A. hungarica Borbas [2], and A. turbith ssp. haynaldii as A. haynaldii Borbas & Uechtr. [3]. Previously, we reported on the fatty acid composition of the fatty oils isolated from mature fruits of A. turbith ssp. hungarica and A. turbith ssp. haynaldii [4]. In this study, the composition and antimicrobial properties of the fruit essential oils of these plants were analysed. The essential oils were obtained from powdered mature fruits by hydrodistillation, according to the procedure of the European Pharmacopoeia 4 [5]. The fruits of A. turbith ssp. hungarica and A. turbith ssp. haynaldii yielded 7.1 and 7.7% (v/w) of essential oil, respectively. The chemical composition of the isolated essential oils was determined using GC/FID and GC/MS analysis. Results are reported in the Table 1. Thirty-seven compounds (99.7% of the total oil) were identified in the essential oil of A. turbith ssp. hungarica (sample 1) and thirteen compounds (98.9% of the total oil) in the essential oil of A. turbith ssp. haynaldii (sample 2). The major component in both essential oils was myristicin (58.6 and 75.9%, in sample 1 and sample 2, respectively), representing the only phenylpropane in the oils. The content of sesquiterpene hydrocarbones was 36.4% in sample 1 and 16.3% in sample 2, while monoterpene hydrocarbones were present in smaller quantities 3.0 and 6.7%, respectively. In the A. turbith ssp. hungarica essential oil oxygenated mono- and sesquiterpenes were present in small quantities (0.5–1.2%), while in the A. turbith ssp. haynaldii essential oil they were absent. In previous studies on the essential oil composition of various Athamanta species a diversity has been noticed. Zivanovic et al. (1994) reported myristicin and β-pinene as the major compounds in the fruit essential oil of A. haynaldii [6]. Myristicin was the main compound in the fruit and leaf essential oil of A. sicula [7]. The most abundant components in the essential oil obtained from aerial parts of A. macrophylla were p-cymene, thymol, and carvacrol [8]. In the essential oil of A. macedonica ssp. macedonica, sabinene was found to be the major constituent [9]. Antimicrobial activity of the isolated essential oils was assayed using the agar diffusion and broth microdilution method, against Gram (+) bacteria Staphylococcus aureus and Enterococcus faecalis, Gram (–) bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli, and a yeast Candida albicans (Tables 2 and 3) [10, 11]. The best inhibitory effect was detected against S. aureus and K. pneumoniae, followed by the effects against E. faecalis, C. albicans ,a nd E. coli. Neither of the oils had activity against P. aeruginosa. The antimicrobial activity of A. turbith ssp. haynaldii essential oil was about two times higher than that of A. turbith ssp. hungarica essential oil, except for E. faecalis, against which the examined essential oils exerted the same activity.