The present investigation was to evaluate the potential trypanocidal activity of crude ethanolic extract of the fruits of Solanum palinacanthum, Solanum lycocarpum and the glycoalcaloid, solamargine. S. palinacanthum and S. lycocarpum fruit powders were submitted to exhaustively extraction with 96% ethanol and solamargine were isolated from the extract of S. palinacanthum. Both extracts and solamargine were analysed for trypanocidal activity by using MTT colorimetric assay. Extracts of S. palinacanthum showed to be more active (IC 50 = 175.9 µg.ml -1 ) than S. lycocarpum (IC 50 = 194.7 µg.ml -1 ). Solamargine presented a strong activity (IC 50 = 15.3 µg.ml -1 ), which can explain the better activity of the both extracts.Benznidazol (IC 50 = 9.0 µg.ml -1 ) is the only drug used to treat Chagas' disease. These findings demonstrate for the first time that ethanol extracts obtained from both fruits of S. palinacanthum and S. lycocarpum and also solamargine have a potential anti-trypanosomal activity.

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The chemical composition of the essential oil isolated from the aerial parts of Melampodium divaricatum (Rich.) DC. (Asteraceae) was characterized by GC-FID and GC/MS analyses. (E)-Caryophyllene (56.0%), germacrene D (12.7%), and bicyclogermacrene (9.2%) were identified as the major oil components. The antimicrobial activity of the oil against seven standard strains of oral pathogens from the American Type Culture Collection (ATCC) was evaluated by determining minimum inhibitory concentrations (MICs) using the microdilution method. MIC Values below 100 μg/ml were obtained against Streptococcus sobrinus (90 μg/ml), Lactobacillus casei (30 μg/ml), S. mutans (20 μg/ml), and S. mitis (18 μg/ml). In contrast, the MIC values of the major oil compound (E)-caryophyllene were higher than 400 μg/ml against all pathogens, suggesting that the activity of the oil might depend on minor oil components and/or on synergistic effects. The M. divaricatum essential oil is a promising agent to include in anticariogenic oral rinse formulations for the control of oral pathogens.

The composition of the essential oil (EO) from leaves of Vernonia polyanthes and the evaluation of its leishmanicidal potential are reported here for the first time. The oil obtained by hydrodistillation was analysed by combination of GC and GC/MS. Thirty-five compounds were identified, representing 91.8% of the oil composition. The oil consists primarily of monoterpenes (37.1%), sesquiterpenes (26.3%) and oxygenated sesquiterpenes (23.9%), myrcene (34.3%), zerumbone (15.8%), bicyclogermacrene (8.9%), α-humulene (4.8%) and germacrene D (4.3%) being the major constituents. Activity against Leishmania infantum was determined using the tetrazolium dye (MTT) colorimetric method. The oil, as well as zerumbone, one of its major constituents, showed significant leishmanicidal activity, with IC values of 19.4 and 9.0 μg/ml, respectively. Cytotoxicity in macrophages cells was evaluated using the MTT colorimetric assay. The EO showed the CC < 10 μg/ml to macrophages cells.

The composition of the essential oils (EO) from leaves and rhizomes of Hedychium coronarium was analyzed both by gas chromatography and gas chromatography-mass spectroscopy. Thirty and thirty-nine compounds were identified, respectively, in the oils from leaves and rhizomes, representing 88% and 86.1% of the whole compositions. Caryophyllene oxide is the major component in rhizomes while 1,8-cineole predominates in leaves oil. Essential oils and major components were tested for trypanocidal activity using procyclic forms of Trypanosoma brucei (427 and 29-13 strains). The cytotoxicity index (CI 50 ), using the MTT colorimetric method, showed that essential oils and 1,8-cineole were inactive (>100 g⋅mL −1 . Nevertheless, caryophyllene oxide revealed a remarkable activity against both T. brucei strains (CI 50 = 65.77 g⋅mL −1 and 24.53 g⋅mL −1 , resp.), and the synergism between caryophyllene oxide plus pentamidine (1 : 1, v/v) highly increased the trypanocidal activity (<1.0 g⋅mL −1 ).