Morphoanatomical study of the species Zanthoxylum kleinii (R.S. Cowan) P.G. Waterman (Rutaceae).

The order Sapindales is comprised of nine families and in Brazil it is represented by six, including Rutaceae Juss., which constitutes the largest group of this order. A variety of species of Zanthoxylum L. are distributed throughout the country, and among them is the species Zanthoxylum kleinii (R.S. Cowan) P.G. Waterman, which is found in the states of Brazil. This study aimed to characterize the morphoanatomy of the leaf, petiole, rachis, and stem of the species Z. kleinii. Histochemical tests were performed, and the sections were visualized under optical and scanning electron microscopy. The analysis showed that the morphoanatomical characteristics of the species are: hypoestomatic leaflets; stomata classified as anomocytic, tetracytic, and anisocytic; dorsiventral mesophyll; cavities that produce a secretion of lipid nature, present in the leaflet, rachis, and petiole; colleters distributed in the leaf; presence of simple non-glandular trichomes in all structures; and prismatic crystals in the petiole. Histochemical tests indicated the presence of phenolic and lipophilic compounds, mucilage, and lignin. With the result of this research, it was possible to identify the nature of the compounds secreted by the secretory structures of the leaves; in addition, the morphoanatomical characterization of Z. kleinii can provide relevant data for future studies for other organs of the species not yet described. Furthermore, contributing concomitantly with data for the genus, in this way, supporting to differentiate them. RESEARCH HIGHLIGHTS: Ultrastructural features observed by microscopic techniques. Calcium oxalate crystals present in the rachis. Microchemical tests confirmed the presence of colleters in the leaflet.

RNA-dependent RNA polymerase (RdRp) natural antiviral inhibitors: a review.

Viral diseases are the cause of many global epidemics, leading to deaths, affecting the quality of life of populations, and impairing public health. The limitations in the treatment of viral diseases and the constant resistance to conventional antiviral treatments encourage researchers to discover new compounds. In this perspective, this literature review presents isolated molecules and extracts of natural products capable of inhibiting the activity of the nonstructural protein that acts as the RNA-dependent RNA polymerase. The literature review presented natural compounds with the potential to be tested as alternative medicines or used in the development of synthetic drugs to prevent the replication of RNA viruses, such as COVID-19, hepatitis C, and dengue viruses, among others. Natural products are known to exhibit remarkable activities in mitigation of different viral diseases, in addition, they help to decrease the aggravation of infections. Consequently, reducing hospitalization time and deaths.

Microscopic investigations of Ocotea paranaensis-A Brazilian endemic and endangered species.

This article describes the morpho-anatomies of the leaves and stems of Ocotea paranaensis Brotto, Baitello, Cervi & Santos (Lauraceae) using light and scanning electron microscopy. The main anatomical features characterizing the species are the presence of simple non-glandular trichomes in the leaves and stems, large secretory cells in the leaves, flat-convex petioles with two small lateral ribs, brachysclereids in the stem cortex and pith, and the presence of starch grains and various types of calcium oxalate crystals in the pith. Histochemical tests indicated the presence of lignin in stone cells, fibers, and xylem. Lipophilic contents were found in the secretory cells. Phenolic compounds were detected in the epidermis, hypodermis, phloem, and xylem. The present study's findings can contribute to the taxonomy and authentication of O. paranaensis. RESEARCH HIGHLIGHTS: This article is the first morpho-anatomical study of Ocotea paranaensis. Anatomy and histochemistry of the leaves and stems were studied by light microscopy, FESEM and EDS. The findings of this study would aid in the species identification and taxonomy.

Chemical composition of the volatile oil of Croton glandulosus Linnaeus and its allelopathic activity.

Several essential oils have allelochemicals with phytotoxic effects. Croton species are producers of secondary metabolites with biological potential. In the present study, chemical composition of the essential oil extracted from aerial parts of Croton glandulosus Linnaeus was evaluated by gas chromatography and the phytotoxicity of the oil on Lactuca sativa seeds was evaluated for the first time. The yield of the essential oil was 0.12% (v/w). Chromatographic analysis allowed the identification of 97.49% of the total compounds present in the oil. Sesquiterpenes were found to be the predominant constituents of the volatile oil, with ß-caryophyllene (53.24%) being the major compound. Treatment with 0.1%-1% (v/v) of the essential oil inhibited the development of the hypocotyl and radicle of L. sativa to a greater extent compared to the inhibition of seed germination, demonstrating the phytotoxic effect of the oil.

Acute and subacute (28 days) toxicity, hemolytic and cytotoxic effect of Artocarpus heterophyllus seed extracts.

BACKGROUND: Plants and their parts are a part of life in many Brazilian communities, as observed in the jackfruit. The jackfruit seeds are consumed, usually, as roasted, boiled, steamed, and are eaten as a snack. OBJECTIVE: The present study was carried out to identify the Artocarpus heterophyllus seeds toxicity and cytotoxic activity. METHODS: The extracts were tested in toxicity assays like, brine shrimp lethality assay, hemolysis assay, and effect of seed extracts on T47D, TH29 and B16F10 cancer cell lines, and in acute and subchronic toxicity in mice. RESULTS: Artocarpus heterophyllus seed presents no toxic effects in brine shrimp, no hemolytic activity, and was effective in cancer cell lines like T47D, TH29 and B16F10. IC50 obtained from extracts was 46.67 µg/ml of chloroform extract in T47D cells, 23.42 µg/ml of ethanolic extract in HT29 cells, and 74.31 µg/ml of ethyl acetic extract in B16F10 cells. Ethanolic extract presented zero lethality index and was able to reduce the level of glycemia in females (32.3%) in the subchronic test. CONCLUSIONS: With this results we can conclude that Artocarpus heterophyllus seeds presents no toxicity, and is very effective in determinated cancer cell lines, requiring further studies to validate their use as active natural product against cancer cells.

Antagonistic activity of Diplodia pinea against phytopathogenic fungi.

The ability of Diplodia pinea to inhibit Armillaria sp., Bjerkandera adusta, Botrytis cinerea, and Rhizoctonia sp. mycelium growth was analyzed using the double-culture method. Wild-type fungal strains were incubated in a biochemical oxygen demand incubator using potato agar dextrose medium at 24 ± 2 °C for 35 days in darkness. D. pinea significantly inhibited the growth of all fungi species tested (30.75 to 98.37% inhibition) and showed moderate antagonistic activity (antagonistic index, 14.5). Chemical analysis of D. pinea culture broth extracts revealed steroids, triterpenes, and phenolic compounds. Alkaloids were qualitatively detected in the mycelium crude extract. The presence of these compounds may be related to the antagonistic activity observed. The inhibition ability of D. pinea is due to competition with the tested fungi for substrate and space.

Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina.

Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer's disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA) and planarian locomotor velocity (pLMV) were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 µmol·min(-1) and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.