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A protocol for in vitro propagation of Rollinia mucosa, an important medicinal plant, was developed. The presence of 500 mg l 21 polyvinylpyrrolidone (PVP) during explant excision was important to avoid browning. Axillary buds, adventitious buds, and shoot cluster proliferation were achieved from epicotyl and hypocotyl explants from nursery-grown seedlings. The highest direct organogenesis percentage from hypocotyl explants was obtained upon culture of explants on Murashige and Skoog medium supplemented with 2.2 mM benzyladenine (BA) plus 2.32 mM kinetin. Epicotyl explants display highest regeneration frequency on a medium containing 8.8 mM BA and 0.54 mM naphthaleneacetic acid. Gibberellic acid was necessary for shoot elongation. Root induction was observed when shoots were pretreated with activated charcoal for 7 d in the dark before culture on Woody Plant Medium supplemented with 49.21 mM indolebutyric acid for 10 d. Root development was observed when 20 g l 21 sucrose was used. Rooted plantlets were acclimatized and grown in the greenhouse.

Giardia lamblia is the causative agent of giardiasis, a common parasitic infection of the human and animal digestive tract. Although several drugs have been available to treat this infection, they present unpleasant side effects or cytotoxicity. In order to find a more natural treatment for the disease, we analyzed the effects of the methanolic extract and three fractions obtained from Hovenia dulcis Thunb. (Rhamnaceae) leaves on G. lamblia. Comparing all fractions, dichloromethane was more efficient in reducing Giardia growth. The exposition of G. lamblia to this fraction lead to degenerations in the surface, modifications in the cell shape and alterations in the localization of nuclei. Besides that, the adhesion of G. lamblia was also altered. Experiments revealed that the obtained fraction did not present cytotoxic effects in mammalian cells. In summary, dichloromethane fraction has strong antigiardial effects and could become an important new substance for the treatment of giardiasis.

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This paper describes a protocol for the efficient vegetative propagation of

Alternative methods for in vitro shoot culture of Cleome rosea, a Brazilian herbaceous species with ornamental value and medicinal potential, were evaluated. A protocol for rapid in vitro multiplication of roots, a valuable source of medicinal compounds, was also developed. Stem explants were cultured in liquid media (continuous immersion and paper bridge), while root explants were cultivated in continuous immersion and on solidified media. The highest numbers of shoots, 20 ± 4.6 shoots/ explant, were obtained from stem explants incubated in a continuous immersion system in a liquid medium supplemented with 2.2 lM BA. Root explants cultivated in liquid media produced only hyperhydrous adventitious shoots. However, these explants generated 5.8 ± 0.8 shoots/ explant by indirect organogenesis when cultivated on solidified medium supplemented with 2.2 lM BA. In addition, root multiplication was achieved in liquid medium in the presence of a-naphthaleneacetic acid. Adventitious shoots developed on newly formed roots when inoculated on solidified medium supplemented with 2.2 lM BA. Shoot microcuttings developed roots when transferred onto solidified MS medium without growth regulators. Rooted microcuttings were efficiently acclimatized when transferred ex vitro.

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The effects of different levels of Murashige and Skoog (MS) basal medium, 2,4-dichlorophenoxyacetic acid (2,4-D), and sucrose on anthocyanin production and biomass accumulation of cell suspension cultures of Cleome rosea were investigated. Cultures were established in liquid MS medium containing 30 g l -1 sucrose and supplemented with 0.90 lM 2,4-D. Proliferating cell suspension cultures achieved the highest growth capacity, a fourfold increase in biomass accumulation, following subculture at the exponential growth phase, 14-18 days of culture. Moreover, the presence of 2,4-D was essential for anthocyanin production and biomass accumulation. On the other hand, increasing levels of sucrose above 30 g l -1 resulted in a drastic reduction in biomass accumulation. Anthocyanin production was highest in cell suspension cultures grown on halfstrength MS medium (1/2 MS), 30 g l -1 sucrose, and 0.45 lM 2,4-D. These cell suspension cultures were mainly composed of small aggregates of spherical cells with similar morphology observed in anthocyanin-producing and non-producing cultures. Moreover, microscopic analysis of anthocyanin-producing cultures showed the presence of mixtures of non-pigmented, low-pigmented, and high-pigmented cells.