Enzymatic, antimicrobial, and leishmanicidal bioactivity of gram-negative bacteria strains from the midgut of Lutzomyia evansi, an insect vector of leishmaniasis in Colombia.

Knowledge regarding new compounds, peptides, and/or secondary metabolites secreted by bacteria isolated from the intestine of phebotominae has the potential to control insect vectors and pathogens (viruses, bacteria, and parasites) transmitted by them. In this respect, twelve Gram-negative bacteria isolated from the intestine of Lutzomyia evansi were selected and screened for their enzymatic, antimicrobial, and leishmanicidal activity. E. cancerogenus, E. aerogenes, P. otitidis, E. cloacae, L. soli, and P. ananatis exhibited enzymatic activity. 83.3% of the isolates displayed lipolytic and nitrate reductase activity and 58.3% of the isolates displayed protease activity. Hemolytic activity (17%) was identified only in E. hormaechei, and P. ananatis. E. cancerogenus, A. calcoaceticus, and P. otitidis showed cellulolytic activity. A. gyllenbergii, P. aeruginosa, and E. hormaechei showed amylolytic activity. In general, the totality of methanolic extracts exhibited antimicrobial activity, where E. hormaechei, A. calcoaceticus, and E. cancerogenus presented the highest activity against the evaluated reference bacteria strains. Cell-free supernatants (CFSS) of the Gram-negative bacteria showed higher growth inhibitory activity against the reference Gram-positive bacteria. The CFS of A. gyllenbergii was the most active antimicrobial in this study, against S. aureus (AAODs = 95.12%) and E. faecalis (AAODs = 86.90%). The inhibition percentages of CFS against Gram-positive bacteria showed statistically significant differences (repeated measure ANOVA df= 2; F= 6.095; P= 0.007832). The E. hormaechei methanolic extract showed leishmanicidal activity (CE-50 µg/ml = 47.7 + 3.8) against metacyclic promastigotes of Leishmania braziliensis (UA301). Based on this finding, we discuss the possible implications of these bacteria in digestion and physiological processes in the Lu. evansi intestine. P. ananatis, E. cloacae, E. hormaechei, and P. otitidis were considered the most promising bacteria in this study and they could potentially be used for biological control.

Chemical Composition, Antimicrobial and Antiparasitic Screening of the Essential Oil from Phania matricarioides (Spreng.) Griseb.

Essential oils (EOs) have gained increasing attention due to their pharmacological effectiveness, and they also constitute some of the most popular natural products. In this study, we present the chemical characterization of the EO from Phania matricarioides and the in vitro activity/selectivity against a wide panel of bacteria, fungi and parasitic protozoa. Forty-five compounds were identified in the studied EO, of which lavandulyl acetate (40.1%) and thymyl isobutyrate (13.9%) were the major components. The EO did not inhibit bacterial or fungal growth at the maximum concentration tested (64 µg/mL), although it displayed activity on all evaluated protozoa (IC50 values ranging from 2.2 to 56.6 µg/mL). In parallel, the EO demonstrated a noteworthy cytotoxic activity against peritoneal macrophages (CC50 values of 28.0 µg/mL). The most sensitive microorganism was Trypanosoma cruzi, which had a superior activity (IC50 = 2.2 µg/mL) and selectivity (SI = 13) in respect to other parasitic protozoa and the reference drug (p < 0.05). Further in vivo studies are needed to evaluate the potential use of this EO and the main compounds as antitrypanosomal agents. To our knowledge, this is the first report of chemical characterization and antimicrobial assessment of the EO from P. matricarioides.

Antimicrobial screening of some medicinal plants from Mato Grosso Cerrado / Triagem antimicrobiana de algumas plantas medicinais do Cerrado de Mato Grosso

Os extratos em hexano, diclorometano, acetato de etila e etanol das entrecascas de Bowdichia virgilioides, Calophyllum brasiliense, Cariniana rubra, Lafoensia pacari e Stryphnodendron obovatum, do rizoma de Simaba ferruginea e do látex de Croton urucurana foram triados contra um painel de bactérias e fungos usando o método de microdiluição em caldo. O látex de Croton urucurana foi o material derivado de planta com maior atividade antimicrobiana. Os extratos em acetato de etila e hexano da entrecasca de Calophyllum brasiliense destacaram-se por suas seletivas atividades antibacterianas. Os extratos polares da entrecasca de Lafoensia pacari notabilizaram-se por suas potentes e seletivas atividades contra leveduras e os extratos polares e não-polares de Bowdichia virgilioides por suas atividades antifúngicas contra hialo-hifomicetos e dermatófitos. Este é o primeiro relato mostrando atividades antifúngicas para os extratos de Cariniana rubra e Simaba ferruginea. Esse trabalho demonstrou a atividade antimicrobiana de plantas medicinais do Cerrado de Mato Grosso em ensaios in vitro e indica que elas podem ser potenciais candidatas para o desenvolvimento de novas estratégias no tratamento de infecções bacterianas e fúngicas.

Hexane, dichloromethane, ethyl acetate and ethanol extracts from stem barks of Bowdichia virgilioides, Calophyllum brasiliense, Cariniana rubra, Lafoensia pacari, and Stryphnodendron obovatum and rhizome of Simaba ferruginea and Dragon's blood red sap from Croton urucurana were screened against a panel of bacteria and fungi using the micro-broth dilution method. Dragon's blood from Croton urucurana was the most effective antimicrobial plant material. Ethyl acetate and hexane extracts of Calophyllum brasiliense stem bark deserved distinction by their selective antibacterial activity. Lafoensia pacari stem bark polar extracts distinguished by their potent and selective anti-yeast activity and Bowdichia virgilioides polar and non-polar extracts by their antifungal activity towards hyalohypho-mycetes and dermatophytes. This is the first report showing antifungal activity for polar extracts of Cariniana rubra and Simaba ferruginea. This study has demonstrated antimicrobial activity of Mato Grosso Cerrado ethnomedicinal plants in in vitro assays and has indicated that they can be effective potential candidates for the development of new strategies to treat fungal and bacterial infections.

Antibacterial, antifungal and cytotoxic activities of eight Asteraceae and two Rubiaceae plants from colombian biodiversity

Thirty crude extracts of eight plants belonging to Asteraceae and two to Rubiaceae families collected at different places from the Regional Natural Park Ucumarí (RNPU), Colombia, were tested for their antibacterial activity against two Gram-positive and two Gram-negative bacteria and three fungi. Both the antibacterial and the antimycotic activities were tested by the agar well diffusion method. The cytotoxic activity on the same plant extracts was determined through the brine shrimp lethality bioassay. The extracts from the Asteraceae family were more bioactive against Bacillus subtilis and Staphylococcus aureus. The extracts of both families studied were bioactive against the fungi Candida albicans and Fusarium solani. In addition, the extracts of Asteraceae species displayed the greatest cytotoxic activities. However, the most important specie in this research was Gonzalagunia rosea Standl (Rubiaceae) because of the strong and moderate activities of the methanol and dichloromethane extracts against C. albicans and F. solani, respectively; as well as the strong cytotoxic activity of the methanol extract. None of these ten plants has previously been reported for their biological activities.

Trinta extratos crus de oito plantas da família Asteraceae e a duas plantas da família Rubiaceae, coletadas em diferentes lugares do Parque Natural Regional Ucumarí (PNRU), Colombia, foram avaliadas quanto à atividade contra duas bactérias Gram-positivas, duas Gram-negativas e três fungos. As atividades antibacteriana e antimicótica foram determinadas pelo método de difusão em agar. A atividade citotóxica dos mesmos extratos foi determinada através do bioensaio de Artemia salina. Os extratos da família Asteraceae foram os mais bioativos contra Bacillus subtilis e Staphylococcus aureus. Os extratos de ambas famílias estudadas foram bioativos contra os fungos Candida albicans e Fusarium solani. Os extratos da família Asteraceae exibiram maior atividade citotóxica. A espécie mais importante desta pesquisa foi Gonzalagunia rosea Standl (Rubiaceae) devido à atividade intensa e moderada dos extratos de metanol e diclorometano contra F. solani e C. albicans, respectivamente, bem como a intensa atividade citotóxica do extrato metanólico. Não se encontraram estudos prévios acerca das atividades biológicas das dez plantas avaliadas nesse estudo.