Phytochemical prospection and evaluation of antimicrobial, antioxidant and antibiofilm activities of extracts and essential oil from leaves of Myrsine umbellata Mart. (Primulaceae).

The species Myrsine umbellata is a native plant of Brazil, whose barks are traditionally used in herbal medicine to treat liver disorders and combat leprosy. Therefore, the aim of the study was to identify the phytochemical prospection of ethanolic (EE) and acetonic (EA) extracts by colorimetric tests and by gas chromatography coupled to mass spectrometry (GC-MS) of the essential oil (EO) of M. umbellata leaves; evaluate the antimicrobial activity in front of standard ATCC strains by the broth microdilution technique; the antioxidant potential by DPPH reduction method and antibiofilm action by crystal violet assay and cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based on optical density. Phytochemical prospection of EE and EA detected the presence of free steroids, alkaloids, flavonoids (flavones, flavononoids, flavonols and xanthons) and tannins in both extracts (EE and EA) and saponins only in EE. In EO, the majority compounds identified were elixene, caryophyllene (E), spatulenol, d-Cadinene and aromadendrene. EA showed antimicrobial activity with MIC and MBC/MFC values ranging from 3.12 to 100 mg.mL-1, highlighting its efficiency on the Gram-positive strain S. epidermidis. EE showed antimicrobial potential in the range of 3.12 to 200 mg.mL-1, and the Gram-negative E. coli strain was the most susceptible. However, OE showed bacteriostatic potential against S. Typhimurium, S. Abaetetuba, P. aeruginosa, and S. epidermidis strains. The ability to sequester free radicals was evident in EA extract with antioxidant activity of 89.55% and in EE with 63.05%. The antibiofilm potential was observed in EE extract which eradicated the mature biofilm biomass of all tested bacteria with high activity (50% to 84.28%) and EO also showed antibiofilm effect on mature biofilm of UEL enteroaggregative E. coli, S. aureus and S. Enteritidis strains with biomass reduction percentage of 63.74%, 68.04% and 86.19%, respectively. These results indicate the potential of M. umbellata extracts and as a source of plant bioactivity for the development of new alternative strategies for the control of planktonic or biofilm-resistant microorganisms.

Phytochemical prospection and evaluation of antimicrobial, antioxidant and antibiofilm activities of extracts and essential oil from leaves of Myrsine umbellata Mart. (Primulaceae) / Prospecção fitoquímica e avaliação da atividade antimicrobiana, antioxidante e antibiofilme de extratos e óleo essencial de folhas de Myrsine umbellata Mart. (Primulaceae)

The species Myrsine umbellata is a native plant of Brazil, whose barks are traditionally used in herbal medicine to treat liver disorders and combat leprosy. Therefore, the aim of the study was to identify the phytochemical prospection of ethanolic (EE) and acetonic (EA) extracts by colorimetric tests and by gas chromatography coupled to mass spectrometry (GC-MS) of the essential oil (EO) of M. umbellata leaves; evaluate the antimicrobial activity in front of standard ATCC strains by the broth microdilution technique; the antioxidant potential by DPPH reduction method and antibiofilm action by crystal violet assay and cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based on optical density. Phytochemical prospection of EE and EA detected the presence of free steroids, alkaloids, flavonoids (flavones, flavononoids, flavonols and xanthons) and tannins in both extracts (EE and EA) and saponins only in EE. In EO, the majority compounds identified were elixene, caryophyllene (E), spatulenol, d-Cadinene and aromadendrene. EA showed antimicrobial activity with MIC and MBC/MFC values ranging from 3.12 to 100 mg.mL-1, highlighting its efficiency on the Gram-positive strain S. epidermidis. EE showed antimicrobial potential in the range of 3.12 to 200 mg.mL-1, and the Gram-negative E. coli strain was the most susceptible. However, OE showed bacteriostatic potential against S. Typhimurium, S. Abaetetuba, P. aeruginosa, and S. epidermidis strains. The ability to sequester free radicals was evident in EA extract with antioxidant activity of 89.55% and in EE with 63.05%. The antibiofilm potential was observed in EE extract which eradicated the mature biofilm biomass of all tested bacteria with high activity (50% to 84.28%) and EO also showed antibiofilm effect on mature biofilm of UEL enteroaggregative E. coli, S. aureus and S. Enteritidis strains with biomass reduction percentage of 63.74%, 68.04% and 86.19%, respectively. These results indicate the potential of M. umbellata extracts and as a source of plant bioactivity for the development of new alternative strategies for the control of planktonic or biofilm-resistant microorganisms.

A espécie Myrsine umbellata é uma planta nativa do Brasil, tradicionalmente suas cascas são empregadas em fitoterapia no tratamento de afecções do fígado e combate a hanseníase. Portanto, o objetivo do estudo foi realizar a prospecção fitoquímica dos extratos etanólico (EE) e acetônico (EA) por meio de testes colorimétricos e por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) do óleo essencial (OE) das folhas de M. umbellata; avaliar a atividade antimicrobiana frente a dozes cepas padrões ATCCs pela técnica de microdiluição em caldo; o potencial antioxidante pelo método de redução de DPPH e ação antibiofilme pela técnica do cristal violeta e a viabilidade celular foi determinada usando 3- (4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio (MTT) com base na densidade óptica. A prospecção fitoquímica dos EE e EA detectou a presença de esteroides livres, alcaloides, flavonoides (flavonas, flavononóis, flavonóis e xantonas) e taninos em ambos os extratos (EE e EA) e de saponinas somente no EE. No OE os compostos majoritários identificados foram elixeno, cariofileno (E), espatulenol, d-cadineno e aromadendreno. O EA apresentou atividade antimicrobiana com valores de CIM e CBM/CFM que variaram de 3,12 a 100 mg.mL-1, destacando sua eficiência sobre a cepa Gram-positiva S. epidermidis. Já EE apresentou potencial antimicrobiano na faixa que variou de 3,12 a 200 mg.mL-1, e a cepa Gram-negativa E. coli foi a mais suscetível. Entretanto, OE apresentou potencial bacteriostático frente às cepas S. Typhimurium, S. Abaetetuba, P. aeruginosa e S. epidermidis. A capacidade de sequestrar radicais livres foi evidenciada no extrato EA com atividade antioxidante de 89,55% e no EE com 63,05%. O potencial antibiofime foi observado no extrato EE que erradicou a biomassa do biofilme maduro de todas as bactérias testadas com elevada atividade (50% a 84,28%) e OE também apresentou efeito antibiofilme sobre o biofilme maduro das cepas E. coli enteroagreativa UEL, S. aureus e S. Enteritidis com percentual de redução de biomassa de 63,74%, 68,04% e 86,19%, respectivamente. Esses resultados indicam o potencial dos extratos e do OE de M. umbellata como fonte de bioativos vegetais para o desenvolvimento de novas estratégias alternativas para o controle de microrganismos resistentes de forma planctônica ou de biofilmes.

Isosporosis and unizoite tissue cysts in patients with acquired immunodeficiency syndrome.

Isospora belli, a coccidian parasite in humans, has been described as causing chronic diarrhea and acalculous cholecystitis in patients with the acquired immunodeficiency syndrome (AIDS). Diagnosis can be made at the tissue level in the epithelium of the small bowel and by fecal examination. Disseminated extraintestinal forms are uncommon. We studied 118 adult patients with AIDS and chronic diarrhea using stool analysis and endoscopy with duodenal biopsy specimen collection. These samples were processed by routine histology and transmission electron microscopy. Isosporosis was diagnosed in 8 cases. In 2 of them, unizoite tissue cysts were present in the lamina propria, with negative results in stool materials. The cysts were located within a large parasitophorous vacuole. There were no structural means of differentiating the species level of Isospora based on morphology using light or electron microscopy. We believe further work should be done to determine if unizoite tissue cysts are part of the cycle of I belli or of other species of Isospora that could be pathogenic in immunocompromised hosts.