Interference of Seasonal Variation on the Antimicrobial and Cytotoxic Activities of the Essential Oils from the Leaves of Iryanthera polyneura in the Amazon Rain Forest.

The essential oils (EOs) obtained from the leaves of Iryanthera polyneura Ducke trees was chemically Assessed and tested for the ability of inhibiting the growth of Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans and S. sanguinis. The oil was also tested against breast (MCF-7) and prostate (PC-3) cancer cell lines. Minimum bactericidal concentrations (MBCs) and 50 % inhibition concentrations (IC50 ) values were obtained. EOs were active against Gram-positive bacteria. Spathulenol, α-cadinol and τ-muurolol were major components of EOs. The oils showed a higher cytotoxicity against PC-3 than MCF-7 cells, although the oils were active against both cell types. Oils obtained from leaves collected in the dry season were more active against E. faecalis, S. aureus and PC-3, while the oils obtained from leaves collected in the rainy season were more active against S. mutans, S. sanguinis and MCF-7. The antibacterial and cytotoxic activities of the essential oils from the leaves of I. polyneura are related to the seasonal climate variation and are influenced by compounds that are minor components of the oils.

First chemical evaluation and toxicity of Casinga-cheirosa to Balb-c male mice.

Laetia suaveolens, known as "casinga-cheirosa", crude extract EB719 has previously shown cytotoxic activity against prostate cancer and squamous cell carcinoma. For the first time, seven molecules were isolated from its apolar-α-tocopherol (1) and sitosterol (2)-and polar-3-O-caffeoylquinic acid (3), 4-O-caffeoylquinic acid (4), 5-O-feruloylquinic acid (5), hyperoside (6), and isoquercitrin (7)-fractions. Acute toxicity was determined in a two-stage experiment: (1) a reduced number of Balb-c male mice received 5000 mg/kg of EB719 to allow evaluation of general activity and other 27 parameters, plus death, up to the establishment of non-lethal dose (NLD), as well as lethal dose 50% (LD50); (2) NLD was administered and diazepam introduced as reference drug. EB719 showed LD50=178.0 mg/kg, and NLD 156.3 mg/kg. In stage one EB719 did not influence general activity, but provoked impairment in grasp reflexes, tail squeeze and breathing; piloerection and cyanosis were increased. In stage two, alterations occurred in auricular reflex, piloerection and breathing after diazepam administration, but not in response to EB719. Intestinal hemorrhage caused by local bleeding was observed after necropsy, and may be the main cause of animals' death other than a systemic effect of the extract. Although the isolated compounds are biologically and pharmacologically active in both men and animal systems, it is premature to relate their occurrence in EB719 to the observed intestine hemorrhage in mice.

In vitro cytotoxic activity of Brazilian plant extracts against human lung, colon and CNS solid cancers and leukemia.

The cytotoxicity of extracts obtained from plants occurring in the Amazon and Atlantic rain forests against NCI-H460, KM-12, SF-268 and RPMI-8226 cancer cell lines was investigated. Expressive activity was observed in the extracts of Toulicia cf. pulvinata, Ampirrhox sp., Macoubea sprucei, Calophyllum brasiliense, Vismia guianensis, Caryocar microcarpum, Xylopia aromatica and Distictella magnoliifolia.

Casinga-cheirosa organic extract impairment over Balb-c male mice behavioral phenotype

ABSTRACT Laetia suaveolens (Poepp.) Benth., Salicaceae, popularly known as "casinga-cheirosa", "caferana", or "laranjinha", is native to Brazil but not endemic to this country. A crude organic extract was obtained from the leaves and stem and intraperitoneally administered in male Balb-c mice. Its behavioral effects were evaluated in the open field and elevated plus maze in a two-stage experiment that assessed ten different parameters related to behavior as locomotion, emotionality, and anxiety. In the first stage of the experiment, intraperitoneal the crude organic extract administration dose-dependently impaired locomotion and emotionality 30–120 min after administration. A significant decrease in defecation was observed, which was related to emotionality. No alterations in the elevated plus maze were found; thus, this apparatus was not used in the next stage of the experiment. In the second stage, the previously determined non-lethal dose of 0.1563 g/kg was intraperitoneally administered, which impaired locomotion and rearing frequency and increased immobility time. Necropsy revealed smooth intestine hemorrhage. Rutin, leucoside, nicotiflorin, guaijaverin, and astragalin were isolated from the crude organic extract. This is the first time that these compounds have been identified in L. suaveolens. In conclusion, the crude organic extract impaired locomotion and emotionality and caused hemorrhage in male Balb-c mice, indicating that its consumption can be harmful to humans and animals. The present results provide a basis for further studies on the pharmacology, toxicology, and natural product chemistry of the crude organic extract.

Influence of the intraperitoneal administration of antitumor Abarema auriculata extract on mice behavior

The organic extract EB689, obtained from the stem of Abarema auriculata (Benth.) Barneby & J.W.Grimes, Fabaceae, commonly known as "saboeiro-ferro", was chemically studied, as well as its influence over behavioral effects such as locomotion, emotionality and anxiety, after intra-peritonial administration were assessed. The open-field and elevated-plus maze were used in experiments divided into two stages. The first stage aimed for the identification of the main effects over behavior using a reduced number of animals against half-fold diluted doses of EB689. The same variables were also tested in a second stage of the experiment using the non-lethal intra-peritoneal dose of 4.8 mg/kg in a larger number of animals. It was observed that EB689 clearly decreased locomotion, which was probably caused by internal hemorrhage causing hypovolemic shock. Although it is the first time lupeol and eucryphin are described in A. auriculata, it is still not clear if they are involved in the toxicology of A. auriculata. The undesirable effects of EB689 are better understood, the basis for further pharmacological assays aiming antitumor activity are supported.

Antibacterial and cytotoxic activity of Brazilian plant extracts - Clusiaceae

Twelve extracts obtained from nine plants belonging to six different genera of Clusiaceae were analyzed against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) bacteria using the microdilution broth assay. Tovomita aff. longifolia, T. brasiliensis, Clusia columnaris, Garcinia madruno, Haploclathra paniculata, and Caraipa grandifolia extracts showed significant results against the bacteria. The organic extract obtained from the leaves of T. aff. longifolia showed minimal inhibitory concentration (MIC) = 70 µg/ml and minimal bactericidal concentration (MBC) = 90 µg/ml against E. faecalis and the organic extract made with the stem of C. columnaris showed MIC = 180 µg/ml and MBC = 270 µg/ml against P. aeruginosa. None of the antibacterial extracts showed lethal activity against brine shrimp nauplii. On the other hand, both aqueous and organic extracts obtained from the aerial organs of Vismia guianensis that were cytotoxic to brine shrimp nauplii did not show a significant antibacterial activity in the assay.