Oregano is a perennial shrub that grows in the mountains of the Mediterranean and Euro/Irano-Siberian regions. This study was conducted to identify the major constituents of the ethanolic Origanum vulgare extract and examine the cytotoxic, antioxidant, and antibacterial properties of the extract but more importantly the contribution of its specific major constituent(s) or their combination to the overall extract biological activity. Gas chromatography/mass spectroscopy analysis showed that the extract contained monoterpene hydrocarbons and phenolic compounds, the major ones being carvacrol and thymol and to a lesser extent p-cymene, 1-octacosanol, creosol, and phytol. A549 epithelial cells challenged with the extract showed a concentration-dependent increase in cytotoxicity. A combination of thymol and carvacrol at equimolar concentrations to those present in the extract was less cytotoxic. The A549 cells pretreated with nonlethal extract concentrations protected against hydrogen-peroxide-induced cytotoxicity, an antioxidant effect more effective than the combination of equimolar concentrations of thymol/carvacrol. Inclusion of p-cymene and/or 1-octacosanol did not alter the synergistic antioxidant effects of the carvacrol/thymol mixture. The extract also exhibited antimicrobial properties against Gram-positive and Gram-negative bacterial strains including clinical isolates. In conclusion, the oregano extract has cytotoxic, antioxidant, and antibacterial activities mostly attributed to carvacrol and thymol.
The pathogenesis of pseudohyperaldosteronism from licorice has been evaluated in 6 male volunteers taking daily 7 g of a commercial preparation of licorice for 7 days, corresponding to an intake of 500 mg/day of glycyrrhizic acid. Pseudohyperaldosteronism was evident during the treatment (increase of body weight, suppression of plasma renin activity and plasma aldosterone, reduction of serum potassium). The ratio (tetrahydrocortisol + allo tetrahydrocortisol)/tetrahydrocortisone in urine increased in 5 cases after 3 days of treatment, without an increase of plasma mineralocorticoid activity (PMA). In the 6th case the urinary ratio was unchanged and PMA increased from the pretreatment value. After 7 days of therapy the ratio remained high and PMA was not measurable in 3 cases, while in the other 3 cases the ratio returned to pretreatment and PMA was higher than pretreatment value. We conclude that the pseudohyperaldosteronism from licorice is initially related to decreased activity of 11 beta-hydroxysteroid-dehydrogenase and afterwards also a direct effect of licorice derivatives on mineralocorticoid receptors becomes evident in some cases. In other cases however the effect on the enzyme is prevailing probably due to individual factors.
In the present study, 3 types of electrodes for recurrent laryngeal nerve (RLN) monitoring are compared: 1) intralaryngeal surface electrodes attached to a conventional endotracheal tube, 2) monopolar needle electrodes placed on the vocal cords by direct laryngoscopy, and 3) bipolar needle electrodes inserted intraoperatively through the cricothyroid ligament. Data were collected from stimulation of 21 RLNs in 16 patients undergoing thyroid surgery. The reliability in terms of distinct electromyographic (EMG) potentials following stimulation of the RLN was 100% with monopolar and bipolar needle electrodes and 76% with intralaryngeal surface electrodes. The mean (+/-SD) amplitudes of the EMG potentials were 1.61 +/- 1.6 mV, 2.37 +/- 1.8 mV, and 0.35 +/- 0.4 mV for the monopolar endolaryngeal, bipolar transligament, and intralaryngeal surface electrodes, respectively. The advantages and disadvantages of each type of electrode are discussed.
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