In vitro evaluation of the protoscolicidal effect of Eucalyptus globulus essential oil on protoscolices of hydatid cyst compared with hypertonic saline, povidone iodine and silver nitrate.

OBJECTIVE: There are various protoscolicidal agents for inactivation of protoscoleces of hydatid cysts before and during surgical operation. The present study was aimed to evaluate the protoscolicidal effect of two concentrations of Eucalyptus globulus on protoscoleces of Echinococcus granulosus sensu lato under in vitro condition and to compare its efficacy with hypertonic saline, povidone iodine and silver nitrate. METHODS: Live protoscoleces obtained from the liver of naturally infected sheep were exposed to 0.5% and 1% of Eucalyptus globulus essential oil, 5% hypertonic saline, 10% povidone iodine and 0.5% silver nitrate for 1 and 3minutes. Phosphate buffered saline was used as a negative control. One percent eosin staining method was used to test the viability of protoscoleces in different groups. RESULTS: While the mean percentage of dead protoscoleces was 6.08% in the control group, the scolicidal power of 5% hypertonic saline was only 6.54% and 6.60% after 1 and 3min respectively. 0.5% E. globulus EO demonstrated 97.38% and 100% scolicidal activity after 1 and 3min respectively. The mean protoscolicidal power of 1% E. globulus EO, 10% povidone iodine and 0.5% silver nitrate was 100% after one minute. CONCLUSIONS: According to the results of this study, E. globulus EO demonstrated high scolicidal power in a short period of time. Hence, this herbal product could be considered as a potent natural scolicidal agent that could be used before and during surgery of hydatid disease.

Effect of ranolazine on cardiac microcirculation in normal and diabetic rats.

UNLABELLED: Ranolazine is a new antianginal drug that is postulated to act through blocking of cardiac late sodium channels and improvement in cardiac blood flow. The present study has been carried out to investigate its possible effect on microcirculation of normal and diabetic rats' cardiac muscle. METHODS: Normal and diabetic rats were anesthetized.The chest was opened and a surface laser Doppler flowmeter probe was sutured on the left ventricle next to the left anterior descending branch of the coronary artery. After 30 minutes of animal adaptation, baseline flow was recorded.Thereafter, ranolazine was injected intravenously (10 mg/kg) through the jugular vein and the changes in the cardiac blood flow were measured every 5 minutes for 30 minutes. Systolic blood pressure and heart rate were also recorded. RESULTS: Although, injection of ranolazine resulted in some reduction of cardiac blood flow, no significant changes were observed in normal and diabetic animals. Ranolazine had no significant effect on systolic blood pressure of either groups studied. Nevertheless, it caused a mild but statistically significant increase in the heart rate of diabetic and normal rats. CONCLUSION: In conclusion, in normal and diabetic rats, no evidence of improvement in intramyocardial blood flow by ranolazine was obtained.

Antioxidant properties of hydroxycinnamic acids: a review of structure- activity relationships.

Hydroxycinnamic acids (HCAs) are important phytochemicals possessing significant biological properties. Several investigators have studied in vitro antioxidant activity of HCAs in detail. In this review, we have gathered the studies focused on the structure-activity relationships (SARs) of these compounds that have used medicinal chemistry to generate more potent antioxidant molecules. Most of the reports indicated that the presence of an unsaturated bond on the side chain of HCAs is vital to their activity. The structural features that were reported to be of importance to the antioxidant activity were categorized as follows: modifications of the aromatic ring, which include alterations in the number and position of hydroxy groups and insertion of electron donating or withdrawing moieties as well as modifications of the carboxylic function that include esterification and amidation process. Furthermore, reports that have addressed the influence of physicochemical properties including redox potential, lipid solubility and dissociation constant on the antioxidant activity were also summarized. Finally, the pro-oxidant effect of HCAs in some test systems was addressed. Most of the investigations concluded that the presence of ortho-dihydroxy phenyl group (catechol moiety) is of significant importance to the antioxidant activity, while, the presence of three hydroxy groups does not necessarily improve the activity. Optimization of the structure of molecular leads is an important task of modern medicinal chemistry and its accomplishment relies on the careful assessment of SARs. SAR studies on HCAs can identify the most successful antioxidants that could be useful for management of oxidative stress-related diseases.

Vasorelaxant effect of ranolazine on isolated normal and diabetic rat aorta: a study of possible mechanisms.

UNLABELLED: Ranolazine, an antianginal drug, acts through blocking the cardiac late sodium channels and/or inhibition of fatty acids beta-oxidation. While its cardiac action has been studied extensively, few studies have focused on its vascular effects. In the present study, the vasodilatory effect of ranolazine on isolated rat aorta in normal and diabetic rats has been studied. METHODS: The effect of cumulative concentrations of ranolazine on aortic rings precontracted with phenylephrine, calcium and KCl (40 and 100 mM; in the absence and presence of glibenclamide) were studied and its potency and maximum relaxant effects were calculated. RESULTS: Ranolazine relaxed the phenylephrine and calcium induced contractions in both the normal and diabetic aortas. It also relaxed the contractions induced by both low and high concentrations of KCl. Preincubation of the tissues with glibenclamide had no effect. The potency and maximum effect of ranolazine did not differ significantly between the normal and diabetic rings except when the tissues were contracted by calcium in which ranolazine showed greater potency toward normal tissues. CONCLUSION: It is concluded that ranolazine could relax the aortic contractions in both normal and diabetic states. It seems that both blockade of alpha-adrenergic receptors and voltage-operated calcium channels contribute to this effect.