Action of plant growth regulators over the development of Lippia alba.Lippia alba, a Brazilian species, from the Verbenaceae family, is planted and used throughout Brazil in traditional medicine such as analgesic, calminative and sedative, using aqueous extract of leaves. This study investigated the effect of GA 3 , ethephon and CCC spray solutions on the growth of L. alba at different times of the year. The experiment was carried out at São Manuel Experimental Station from the Universidade Estadual Paulista in Botucatu, Brazil, from December 1995 to December 1996. The experiment consisted of 7 treatments with three replications in complete randomized blocks, and the treatment was applied to the plots and at harvest time, to the subplots. The treatments included control, giberellic acid (GA 3 50 and 100 mg.L -1 ), 2-cloroetil-fosfonic acid (ethephon 100 and 200 mg.L -1) and 2-cloroetil-trimetil ammonium chloride (CCC-1000 and 2000 mg.L -1 ). The vegetable regulators were applied at two different periods, forty and a hundred days after establishment of the experiment, and the growth of the plants was evaluated six times. After the first application, the plants were collected at intervals of 14 days. Plant growth regulators GA 3 , and CCC tended to elevate the results of the evaluated parameters (dry matter of stem, leaves, flowers and total) but the results always stayed smaller or equal to the control.

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The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.