ABSTRACT
Psidium myrsinites DC. is species known as "araçá", from the Cerrado (savanna) biome in Brazil. It is commonly used as a medicinal plant in the treatment of diarrhea because of its astringent properties. The aims of this study were to carry out phytochemical screening with an exploratory purpose; to investigate toxicity by brine shrimp (Artemia salina) lethality bioassay; and to evaluate antimicrobial activity against Gram-positive and Gram-negative bacteria by determining the minimum inhibitory concentration of the essential oil, acetonic and ethanolic crude extracts, and the fractions obtained with organic solvents of Psidium myrsinites DC. leaves. The phytochemical profile determined the major classes of secondary metabolites present as phenolic compounds (tannins, coumarins, flavonoids, anthraquinone glycosides and terpene compounds). The essential oil and hexane fraction demonstrated a level of strong and mild toxicity respectively, thus encouraging further research with isolated substances from them. The crude ethanolic and acetonic extracts, and hexane fractions, chloroform intermediary, ethyl acetate and aqueous fraction from crude acetonic extract showed the best inhibitory effect on bacterial growth of Gram-positive bacteria with minimum inhibitory concentrations ranging between 62.5 and 250 µg.mL-1. However, the presence of secondary compounds such as tannins, flavonoids and terpenes is probably associated with the inhibitory effect on tested microorganisms, which could justify the medicinal use of the leaves of this species.
Psidium myrsinites DC. é uma espécie do bioma Cerrado conhecida como "araçá" comumente utilizada como planta medicinal no tratamento de diarreias e na cicatrização devido as suas propriedades adstringentes. O objetivo deste trabalho foi realizar a triagem fitoquímica com propósito exploratório e a investigação da toxicidade pelo teste de letalidade em Artemia salina e da atividade antimicrobiana contra bactérias Gram-positivas e Gram-negativas pela determinação da concentração mínima inibitória do óleo essencial, dos extratos brutos acetônico e etanólico, além das frações obtidas com solventes orgânicos de polaridade crescente: hexano, clorofórmio, acetato de etila das folhas de Psidium myrsinites DC. O perfil fitoquímico determinou as principais classes de metabólitos secundários presentes como compostos fenólicos (taninos, cumarinas, flavonoides, heterosídeos antraquinônicos e compostos terpênicos. O óleo essencial e a fração hexano demonstraram nível de toxicidade forte e moderado respectivamente, incentivando assim novas pesquisas com substâncias isoladas dos mesmos. Os extratos brutos etanólico e acetônico, e as frações hexano, intermediária de clorofórmio, acetato de etila e fração aquosa do extrato bruto acetônico demonstraram melhor ação inibitória sobre o crescimento bacteriano de bactérias Gram-positivas com concentrações mínimas inibitórias variando entre 62,5 e 250 µg.mL-1. Contudo, a presença de compostos secundários tais como, taninos, flavonoides e terpenos, provavelmente, está associada ao efeito inibitório sobre os micro-organismos testados, o que poderia justificar o uso medicinal das folhas dessa espécie.
Subject(s)
Artemia , Tannins , Oils, Volatile , Psidium/toxicityABSTRACT
Aim: The aims of this study were to evaluate the wound healing potential in vivo and the cytotoxic effects in vitro of Psidium guajava (Myrtaceae) leaf extract and commonly used corticosteroids. Methods: The healing effect was studied in vivo by the clinical and histological evaluation of traumatic lesions in the oral mucosa of rats treated with these substances. Each rat received 2 daily applications of the medicine tested and the animals were sacrificed after 1, 3, 5, 7 and 14 days. Tissue sections stained with hematoxylin & eosin were analyzed. The histological evaluation involved a 5-point scoring system based on the degree of healing, ranging from 1 (total repair of epithelium and connective tissue) to 5 (epithelial ulcer and acute inflammatory infiltrate). The Kruskal-Wallis test was used for statistical analysis of the histological scores. For the in vitro toxicity assay, each substance was applied to mucosa fibroblast cell cultures in conditioned media. The media were conditioned by placing the substances in contact with fresh culture medium for 24 h. The cytotoxicity analysis was performed using the MTT assay. Data were analyzed statistically by ANOVA and Tukeys test at 5% significance level. Results: In vitro, the guava extract caused a decrease in the cell viability and growth when compared to the control and corticosteroids. In vivo, guava extract caused accelerated wound healing from the 3rd day, whereas the corticosteroids delayed tissue repair and were associated with bacterial surface colonization, the presence of micro-abscesses and intense inflammatory infiltrate in the submucosa. Conclusions: Although in a short-term cytotoxicity analysis, the guava extract reduced the cell population in vitro, while in vivo, the extract accelerated wound healing.
Subject(s)
Animals , Adrenal Cortex Hormones/therapeutic use , Plant Leaves/toxicity , Guided Tissue Regeneration , In Vitro Techniques , Phytotherapy , Psidium/toxicity , Cell Culture Techniques , Plants, Medicinal/toxicity , Rats , Data Interpretation, Statistical , Time FactorsABSTRACT
La guayaba (Psidium guajava L.) es una fruta tropical de gran aceptación en los trópicos, donde se consume fresca y procesada. En este trabajo se comparó la acidez libre, el pH, el contenido de cenizas, nitrógeno y la humedad, junto con el contenido de polifenoles totales y la capacidad antioxidante de la piel, el casco y la pulpa de la fruta fresca, y de la pulpa procesada y la mermelada de guayaba. El mayor contenido de polifenoles fue encontrado para la piel de la guayaba (10.36 g/100 g piel) y el menor en la mermelada (1.47 g/100g mermelada), expresados en base seca. Se encontró que la capacidad antioxidante de la piel fue diez veces superior a la de la pulpa, y la de la mermelada el doble que la del casco