Antileishmanial activity and cytotoxicity of Brazilian plants.

Leishmaniasis is a major public health problem, and the alarming spread of parasite resistance has increased the importance of discovering new therapeutic products. The present study aimed to investigate the in vitro leishmanicidal activity from 16 different Brazilian medicinal plants. Stationary-phase promastigotes of Leishmania amazonensis and murine macrophages were exposed to 44 plant extracts or fractions for 48 h at 37°C, in order to evaluate their antileishmanial activity and cytotoxicity, respectively. The most potent extracts against L. amazonensis were the hexanic extract of Dipteryx alata (IC50 of 0.08 µg/mL), the hexanic extract of Syzygium cumini (IC50 of 31.64 µg/mL), the ethanolic and hexanic extracts of leaves of Hymenaea courbaril (IC50 of 44.10 µg/mL and 35.84 µg/mL, respectively), the ethanolic extract of H. stignocarpa (IC50 of 4.69 µg/mL), the ethanolic extract of Jacaranda caroba (IC50 of 13.22 µg/mL), and the ethanolic extract of J. cuspidifolia leaves (IC50 of 10.96 µg/mL). Extracts of D. alata and J. cuspidifolia presented higher selectivity index, with high leishmanicidal activity and low cytotoxicity in the mammalian cells. The capacity in treated infected macrophages using the extracts and/or fractions of D. alata and J. cuspidifolia was also analyzed, and reductions of 95.80%, 98.31%, and 97.16%, respectively, in the parasite burden, were observed. No nitric oxide (NO) production could be observed in the treated macrophages, after stimulation with the extracts and/or fractions of D. alata and J. cuspidifolia, suggesting that the biological activity could be due to mechanisms other than macrophage activation mediated by NO production. Based on phytochemistry studies, the classes of compounds that could contribute to the observed activities are also discussed. In conclusion, the data presented in this study indicated that traditional medicinal plant extracts present effective antileishmanial activity. Future studies could focus on the identification and purification of the antileishmanial compounds within these plants for analysis of their in vivo antileishmanial activity.

Left ventricular twist: comparison between two- and three-dimensional speckle-tracking echocardiography in healthy volunteers.

AIMS: left ventricular (LV) twist is the result of clockwise rotation of the base and counterclockwise rotation of the apex. The aims of this study were to investigate the feasibility of the three-dimensional speckle-tracking echocardiography (3DSTE) to assess LV twist values and compare the data measured by two-dimensional speckle-tracking echocardiography (2DSTE) in a group of healthy volunteers. METHODS AND RESULTS: fifty individuals were enrolled in the protocol. LV twist was defined as net difference between averaged 2DSTE apical (4 segments) and basal (6 segments) rotations. 3DSTE twist was obtained from the LV volumetric image and shown as the averaged global value of 16 segments. Time-to-peak by both techniques was also measured and compared. Significant differences between the two techniques were calculated using the paired Student t-test. P-values of <0.05 were considered significant. Reliable LV twist measurement was possible in 39 of 50 individuals (78%). 2DSTE twist mean peak value was 13.8 + 7.9° with a mean time-to-peak of 388.3 ± 152.3 ms and global 3DSTE twist mean peak value was 10.2 + 7.6° with a mean time-to-peak of 371.8 ± 127.5 ms. Peak LV twist values by 3DSTE was significantly smaller than by 2DSTE (P < 0.01) whereas time-to-peak results showed no significant difference. CONCLUSION: 3DSTE is feasible to assess LV twist deformation. Whereas further investigations using 3DSTE are needed to validate this promising technology, comparing 2DSTE and 3DSTE should be done with caution, as values for peak LV twist differ.

Endocardial border delineation during dobutamine infusion using contrast echocardiography.

BACKGROUND: A significant percentage of pharmacologic stress echocardiograms produce suboptimal images despite the use of second harmonic imaging. Intravenous continuous infusion of myocardial ultrasound contrast may enhance endocardial border delineation during dobutamine-atropine stress echocardiography (DASE), improving wall-motion analysis. PATIENTS AND METHODS: We prospectively studied 68 patients (41 males and 27 females), mean age 58 years, with DASE during intravenous infusion of contrast using second harmonic imaging. Dobutamine was infused in scalar doses of 5 microg/kg/min to 40 microg/kg/min, and atropine was administered in doses of up to 1 mg. We diluted 0.1 mL of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles into 80 mL of saline solution, which was used for continuous intravenous infusion. Blinded reviewers used a 16-segment model at rest and peak DASE to analyze segmental wall delineation in two sets of images for each patient, with and without contrast. An endocardial delineation score of 0-3 (nondelineated to excellent delineation) was given to each segment. An endocardial delineation score index (EDSI), the number of endocardial delineation scores for each set of images divided by 16, was created. RESULTS: The analysis of the mean EDSI for the 2176 segments was 1.46 (+/- 0.43) at rest and 1.30 (+/- 0.48) at peak for noncontrast images and 2.22 (+/- 0.52) and 2.29 (+/- 0.52) for contrast images. Complete left ventricle opacification was obtained in all patients, with a mean dose of 4 mL/min, although in 15 (22%) patients, signs of apical bubble destruction occurred. There were 1768 (81%) of 2176 segments delineated without contrast enhancement and 2057 (95%) of 2176 with enhancement (P < 0.05). CONCLUSION: Continuous infusion of myocardial ultrasound contrast improves endocardial border delineation using second harmonic imaging in patients undergoing DASE.