The S. lycocarpum preparation may be useful against leishmaniasis and may have a good safety index, warranting further investigations into its active constituents and mechanism(s) of action.

Context Ischemic-reperfusion injury is accompanied by a decreased contractility of the myocardium. Positive-inotropic agents have proven useful for treating this condition but may exert serious side-effects. Objective In this study, aqueous preparations from Abelmoschus esculentus L. Moench (Malvaceae), Annona muricata L. (Annonaceae), Bixa orellana L. (Bixaceae), Cecropia peltata L. (Moraceae), Erythrina fusca Lour. (Fabaceae), Psidium guajava L. (Myrtaceae) and Terminalia catappa L. (Combretaceae) were evaluated for their ability to improve the decreased contractility of isolated guinea pig atria after hypoxic stress. Materials and methods Guinea pig atria isolated in Ringer-Locke buffer gassed with 100% O2 at 30 °C were exposed for 5 min to hypoxia, then allowed to recover in oxygenated buffer alone or containing a single plant extract (0.001-1 mg/mL). The contractility (g/s) and beating frequency (beats/min), as well as troponin C contents of the bathing solution (ng/mL), were determined and expressed as means ± SDs. Results The extracts of A. muricata, B. orellana, C. peltata and T. catappa caused an increase in the contractility compared to untreated atria of 340 ± 102%, 151 ± 13%, 141 ± 14% and 238 ± 44%, respectively. However, the latter two preparations increased the troponin C contents of the bathing solution to 36 ± 11 and 69 ± 33, compared to the value of 11 ± 3 ng/mL found with untreated atria. Conclusions Preparations from A. muricata and B. orellana may possess positive-inotropic properties which may improve the contractility of the post-hypoxic myocardium. Studies to assess their usefulness in ischemic-reperfusion injury are warranted.

Preparations from the leaves of Kalanchoe pinnata (Lam.) Pers. (Crassulaceae), Asclepias curassavica L. (Asclepiadaceae), Amaranthus spinosus L. (Amaranthaceae), Bixa orellana L. (Bixaceae), Cymbopogon citratus L. (Poaceae), Caesalpinia pulcherrima (L.) Schwartz (Caesalpiniacese) and Solanum jamaicense Mill. (Solanaceae), as well as the peels of Punica granatum L. (Punicaceae), are popularly used in Suriname to relieve respiratory distress. To verify this claim, aqueous extracts from certain parts of these plants were assessed at 0.001-10 mg mLG for their ability to reduce the force of smooth muscle contraction of isolated 1 guinea pig trachea chains induced by acetylcholine (3×10G M) or histamine (10G M). Experiments 5 5 were carried out in Tyrode buffer mixed with 5% CO in air and at 37°C. The extract from 2 K. pinnata (10 mg mLG) reduced the force of contraction of the tracheal chains caused by both 1 acetylcholine and histamine by 40-70%. Those from P. granatum, A. spinosus, A. curassavica and B. orellana (1 and 10 mg mLG) counteracted the force of contraction by histamine by 30-70%. The 1 preparations from C. pulcherrima, C. citratus and S. jamaicense did not affect the force of contraction due to either acetylcholine or histamine. These results suggest that preparations from K. pinnata, A. spinosus, A. curassavica, B. orellana and P. granatum may elicit bronchospasmolytic effects through antagonism of the muscarinic and/or H histamininergic receptor.

This work was carried out in collaboration among all authors. Author DRAM designed and supervised the study, wrote the protocol, and wrote the first draft of the manuscript. Authors JRT and RB supervised the laboratory studies and performed the statistical analyses. Authors JAH and KO were in charge of the plant collections and extractions. Authors MD, PF and JP carried out and interpreted the cell culture studies. Authors IM and RCS carried out and interpreted the zebra fish studies.

Angiogenesis is an important part of the wound healing process. In this study, the aqueous extracts from seven plant species that are used for wound care in the Republic of Suriname (South America), were evaluated at sub-toxic concentrations for their stimulatory effects on the closure of scratch-wounds in cultured human umbilical vein endothelial cells (HUVECs), the formation of capillary-like structures by these cells, and the growth of sub-intestinal blood vessels in developing Tg (fli1a: EGFP) y1/+ zebrafish embryos. Sub-toxic extract concentrations were about one-third of IC50 values in HUVECs which were established using a sulforhodamine B assay after a 3-day exposure period. Data were expressed relatively to those found with untreated controls and considered statistically significantly different from each other when p values < 0.05 (ANOVA). When compared to untreated controls, the Oenocarpus bacaba stembark extract decreased HUVEC scratch-wound areas by about 30%; increased tube length, number of branching points, and number of loops formed by HUVECs by 50-70%, and increased total sub-intestinal blood vessel length in the zebrafish embryos by about 30%. The extracts from Morinda citrifolia (leaf), Luffa acutangula (fruit juice), Momordica charantia (leaf), Psidium guajava (leaf), Cecropia peltata (branch tops), and Spondias mombin (leaf) had no statistically significant effect on any of these variables. These observations suggest that the O. bacaba sample, unlike the other samples, possessed pro-angiogenic properties which may be involved in its beneficial effects in wound healing. Future studies should more elaborately evaluate these plants in order to definitely establish their therapeutic value in wound healing.