ABSTRACT
Ephedroid macrofossils have been widely documented in Cretaceous deposits, including numerous from the Lower Cretaceous Yixian Formation of NE China. However, few ephedroid macrofossils have been reported from South America. Herein, we describe a new plant of the family Ephedraceae, Arlenea delicata gen. et sp. nov., from the Lower Cretaceous Crato Formation of the Araripe Basin, Northeast Brazil, based on the vegetative and reproductive structures. It has the typical morphological characteristics of ephedroid plants, including fertile reproductive branches, opposite phyllotaxy, terminal female cones, a sympodial branching system, longitudinally striated internodes, and swollen nodes. Our new finding is unusual in having inner chlamydosperms subtended by two pairs of bracts, reproductive units connected to branches through swollen receptacles and a smooth seed surface. This new ephedroid taxon from the Crato Formation increases our understanding of plant diversity of this group during the Early Cretaceous. Furthermore, the general morphology (fleshy bracts and enlarged receptacles) of this new fossil discovery indicates that seeds of this plant may have been dispersed by animals such as pterosaurs (mainly the Tapejaridae) and birds (Enantiornithes and Ornituromorpha). If true, this would explain the cosmopolitan distribution of Ephedraceae in the Lower Cretaceous.
ABSTRACT
Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are the primary bacteria that cause clinical infections, such as urinary and intestinal infections, pneumonia, endocarditis, and sepsis. Bacterial resistance is an innate natural occurrence in microorganisms, resulting from mutations or the lateral exchange of genetic material. This serves as evidence for the association between drug consumption and pathogen resistance. Evidence has demonstrated that the association between conventional antibiotics and natural products is a promising pharmacological strategy to overcome resistance mechanisms. Considering the large body of research demonstrating the significant antimicrobial activities of Schinus terebinthifolius Raddi, the present study aimed to evaluate the chemical composition and antibiotic-enhancing effects of Schinus terebinthifolius Raddi essential oil (STEO) against the standard and multidrug-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The STEO was extracted by hydrodistillation using a Clevenger-type vacuum rotary evaporator. The Minimum Inhibitory Concentration (MIC) of the STEO was assessed by the microdilution method to evaluate the antibacterial activity. The antibiotic-enhancing activity of the essential oil was assessed by determining the MIC of antibiotics in the presence of a sub-inhibitory concentration (MIC/8) of the natural product. The GC-MS analysis revealed alpha-pinene (24.3%), gamma-muurolene (16.6%), and myrcene (13.7%) as major constituents of the STEO. The STEO potentiated the enhanced antibacterial activity of norfloxacin and gentamicin against all the strains and increased the action of penicillin against the Gram-negative strains. Therefore, it is concluded that although the STEO does not exhibit clinically effective antibacterial activity, its association with conventional antibiotics results in enhanced antibiotic activity.
ABSTRACT
ABSTRACT Salinity is one of the major problems of modern agriculture, affecting physiological, growth and plant production. Basil (Ocimum basilicum) is a plant widely used in cooking, and in the pharmaceutical and cosmetics industries. Salicylic acid can be a strategy to mitigate the harmful effects of saline stress on basil plant. The present study aimed to evaluate plants with, gas exchange, chlorophyll a fluorescence and chlorophyll indices of basil (cv. Cinnamon) plants under saline stress and salicylic acid. The experimental design was a randomized block design in a 5x5 incomplete factorial scheme generated through the central composite design. The factors we five electrical conductivities of irrigation water (ECw- 0.5, 1.3, 3.25, 5.2 and 6.0 dS m-1) and five doses of salicylic acid (SA- 0.0, 0.29, 1.0, 1.71 and 2.0 mM), with five replications and two plants per replicate. Growth, gas exchange, chlorophyll a fluorescence and chlorophyll indices of O. basilicum cv. Cinnamon were evaluated. Canonical variables analysis and confidence ellipses (p ≤ 0.01) were performed to study the interrelationship between variables and factors. Salicylic acid alleviated the deleterious effects of salt stress on growth, gas exchange, chlorophyll fluorescence and chlorophyll indices of basil.
RESUMEN La salinidad es uno de los mayores problemas de la agricultura moderna, afectando la fisiología, el crecimiento y la producción vegetal. La albahaca (Ocimum basilicum) es una planta muy utilizada en la cocina y en las industrias farmacéutica y cosmética. El ácido salicílico puede ser una estrategia para mitigar los efectos nocivos del estrés salino en las plantas de albahaca. El objetivo del presente estudio fue evaluar el crecimiento, intercambio de gases, fluorescencia de clorofila a e índices de clorofila de plantas de albahaca (cv. Cinnamon) bajo estrés salino y ácido salicílico. El diseño experimental fue un diseño de bloques al azar en un esquema factorial incompleto de 5x5 generado a través del diseño compuesto central. Los factores fueron cinco conductividades eléctricas del agua de riego (ECw- 0,5, 1,3, 3,25, 5.2 y 6,0 dS m-1) y cinco dosis de ácido salicílico (SA- 0,0, 0,29, 1,0, 1.71 y 2,0 mM), con cinco repeticiones y dos plantas por réplica. Crecimiento, intercambio de gases, fluorescencia de clorofila a e índices de clorofila de O. basilicum cv. Cinnamon fue evaluado. Se realizaron análisis de variables canónicas y elipses de confianza (p≤ 0.01) para estudiar la interrelación entre variables y factores. El ácido salicílico alivió los efectos nocivos del estrés salino sobre el crecimiento, el intercambio de gases, la fluorescencia de la clorofila y los índices de clorofila de la albahaca.
ABSTRACT
Many pathological problems are initiated by ultraviolet radiation (UVR), such as skin cancer, the most commonly diagnosed cancer worldwide. The UVA (320-400 nm) and UVB (290-320 nm) wavelengths may cause effects such as photoaging, DNA damage, and a series of cellular alterations. The UVA radiation can damage the DNA, oxidize the lipids, and produce dangerous free radicals, which can cause inflammation, modify the gene expression in response to stress, and weaken the skin immune response. With a minor penetration, the UVB radiation is more harmful, being responsible for immediate damage. Ultraviolet radiation light emitted by the sun is considered necessary for the existence of life but cause radiation problems, especially in the skin. The photoprotective activities of plant extracts and isolated composts were evaluated by many reports, as well as the correlation of these compounds with the antioxidant activity. This review presents plant compounds with interest to the cosmetic industry to be used in sunscreens such as flavonoids and cinnamates.
ABSTRACT
Popularly known as "açoita-cavalo" (whips-horse), Luehea species (Malvaceae-Tilioideae) are native to America and are used in folk medicine as anti-inflammatory, antidiarrheal, antiseptic, expectorant, and depurative and against skin infections. Although there are studies showing the chemical constituents of some species, the active substances have not been properly identified. A systematic study was carried out through a computer search of data on CAPES journals, SciELO, ISI Bireme, PubMed, ScienceDirect, ScienceDomain Medline, and Google Scholar from published articles using key words: Luehea, açoita-cavalo, and Malvaceae. Luehea divaricata was the species with the highest number of studies observed. Triterpenes (9), flavonoids (6), and steroids (4), including saponins, organic acids (4), and one lignan, are the main types of secondary metabolites registered and the most cited flavonoids were rutin and quercetin and among triterpenes there was maslinic acid, which might be associated with the popular indication of its anti-inflammatory action. The vitexin, a C-glycosylated flavone, isolated from three different species, is cited as a possible taxonomic marker of the genus. Studies confirm in part the medicinal uses of plants named as "açoita-cavalo" species. Some pharmacological activities, not assigned to the species of the genus Luehea by populations, were observed in laboratory experiments.
ABSTRACT
This work describes the antiparasitic and cytotoxic activities of three plant species from the Cerrado biome, Northeastern Brazil. Significant antiparasitic inhibition was observed against Trypanosoma cruzi (63.86%), Leishmania brasiliensis (92.20%) and Leishmania infantum (95.23%) when using ethanol extract from leaves of Guazuma ulmifolia Lam. (Malvaceae), at a concentration of 500 µg/mL. However, low levels of inhibition were observed when assessing leishmanicidal and trypanocidal (Clone CL-B5) activities of crude ethanol extracts from leaves and bast tissue of Luehea paniculata (Malvaceae) and leaves and bark of Prockia crucis (Salicaceae) at a concentration of 500 µg/mL. The extracts revealed the presence of phenolic acids such as gallic acid, chlorogenic acid, caffeic acid and rosmarinic acid, as well as flavonoids such as rutin, luteolin, apigenin and quercetin - the latter detected only in G. ulmifolia. G. ulmifolia extract displayed higher leishmanicidal activity probably due to the presence of quercetin, a potent known leishmanicidal compound. A cytotoxicity test indicated values over 50% at the highest concentration (1000 µg/mL) for all natural products, which were considered cytotoxic. This points out the need for further tests to enable future in vivo trials, including antineoplastic activity on human tumor cells.