Inhibition of quorum sensing regulated bacterial functions by plant essential oils with special reference to clove oil.

AIMS: To evaluate quorum sensing (QS) inhibitory activity of plant essential oils using strains of Chromobacterium violaceum (CV12472 and CVO26) and Pseudomonas aeruginosa (PAO1). METHODS AND RESULTS: Inhibition of QS-controlled violacein production in C. violaceum was assayed using disc diffusion and agar well diffusion method. Of the 21 essential oils, four oils showed varying levels of anti-QS activity. Syzygium aromaticum (Clove) oil showed promising anti-QS activity on both wild and mutant strains with zones of pigment inhibition 19 and 17 mm, respectively, followed by activity in cinnamon, lavender and peppermint oils. The effect of clove oil on the extent of violacein production was estimated photometrically and found to be concentration dependent. At sub-MICs of clove oil, 78.4% reduction in violacein production over control and up to 78% reduction in swarming motility in PAO1 over control were recorded. Gas chromatography-mass spectrometry analysis of clove oil indicated presence of many phytocompounds. Eugenol, the major constituent of clove oil could not exhibit anti-QS activity. CONCLUSIONS: Presence of anti-QS activity in clove oil and other essential oils has indicated new anti-infective activity. The identification of anti-QS phytoconstituents is needed to assess the mechanism of action against both C. violaceum and Ps. aeruginosa. SIGNIFICANCE AND IMPACT OF THE STUDY: Essential oils having new antipathogenic drugs principle because of its anti-QS activity might be important in reducing virulence and pathogenicity of drug-resistant bacteria in vivo.

[Oxidation stress, insulin resistance and endothelial dysfunction during the treatment of hyperlipidaemia]. / Oxidacní stres, inzulínová rezistence a endoteliální dysfunkce v prubehu lécby hyperlipidémie.

BACKGROUND: Hyperlipidaemia represents one of the major risk factors of the type 2 diabetes mellitus (DM2). In the pathogenesis of insulin resistance (IR) development glucose homeostasis impairment and their progression into DM2, oxidative stress and endothelial dysfunction (ED) may play an important role. Recent papers indicate the possibility to prevent the development of DM2 by HLP treatment, which is characterised by increased oxidation stress and ED. METHODS AND RESULTS: For the period of twelve months 46 patients with primary HLP (group S) (LDL-C > 4.1 mmol/l a TG < 3.5 mmol/l), were treated with atorvastatine 20 mg or simvastatine 40 mg. Patients with LDL-C > 4.1 mmol/l along with TG > 3.5 mmol/l were randomly divided into two groups. The SF group was treated with a combination of statin + 200 mg micronized fenofibrate each day, and group SR received together with statin a compound containing n-3 polyene fatty acids (PUFA n-3) in the daily dose of 3.6 g. After one year lasting therapy we found beside the positively influenced concentration of atherogenic lipids and lipoproteins in the group S and SF a significantly reduced concentration of conjugated dienes (CD) in LDL ( -21, resp. 16%, both P < 0.05); the test of KD kinetics in LDL in the group S has marginal increase of the lag phase (P = 0.06) and in the groups S and SR also a significant improvement of ED (increase by the flow of mediated vasodilation, FMD) by 20%, resp. by 18% (both P < 0.05) and in the SR group a significant decrease of microalbuminuria. We did not proved significant concentrations of insulin, C-peptide or indexes showing the degree of IR (HOMA and QUICKI) CONCLUSIONS: Long-lasting hypolipidemic treatment positively affected in our study the oxidative stress and ED, however, it did not resulted in changes of IR.

[Tako-tsubo cardiomyopathy--our experience and review of current knowledge]. / Tako-tsubo kardiomyopatie--nase zkusenosti a prehled aktuálních poznatku.

BACKGROUND: Tako-tsubo cardiomypathy is a relatively novel heart syndrome characterized by acute onset of reversible left ventricular apical ballooning, in the absence of significant epicardial artery stenosis that mimics acute coronary syndromes. The most common clinical presentations are chest pain and dyspnoea, frequently preceded by an episode of emotional or physiologic stress, ST-segment elevation or T wave changes in the precordial leads, minor cardiac biomarker release, and transient wall-motion abnormalities involving the left ventricular apex and mid-ventricle despite the absence of obstructive epicardial coronary artery disease. The syndrome more often affects postmenopausal women. The in-hospital course is uncomplicated; mortality rate seems to be low, as does the risk for recurrence. METHODS AND RESULTS: In this paper, we present case series of 6 consecutive patients admitted to our institution with acute onset of transient left ventricular apical ballooning in the absence of epicardial coronary artery involvement. CONCLUSIONS: Demographic characteristics, clinical features and course of disease were consistent with description of tako-tsubo cardiomyopathy.