Less is more: partial larvicidal efficacy of plant leachate leads to larger Aedes aegypti mosquitoes.

Major efforts to control the population of Aedes aegypti mosquitoes involve the use of synthetic insecticides, which can be harmful to the environment. Most plant compounds are eco-friendly and some of them have biocontrol potential, whereas a fraction of these compounds is released into the environment through the leaf-leaching process. We evaluated the effects of secondary compounds from Ateleia glazioviana and Eucalyptus grandis senescent leaf leachates on Ae. aegypti larval mortality, adult emergence time, and wing size using a microcosm approach. The microcosms consisted of 10 larvae kept in water (control) and under four treatments with leachates from a combination of plant species and leaching time (7 or 14 days). Chemical analyses of the leachates showed the presence of carboxaldehyde and Heptatriocotanol, which have antimicrobial properties, potentially reducing the food available for larvae. ß-Sitosterol, Stigmasterol, α-Amyrin, and Lupeol are compounds with inhibitory, neurotoxic, and larvicidal effects. Both plant species' leachates increased larval mortality and decreased emergence time due to the presence of compounds toxic to the larvae. Larger organisms emerged in treatments with 7-days leachates, likely due to the high concentration of dissolved organic matter in the leachates. The higher mortality in 7-days leachates may also increase the organic matter from co-specific decomposition, improving adult size. Therefore, if the mosquito population is not locally extinct, compounds present in leaf leachates may act as a resource enhancing larvae growth, potentially increasing survivors' fitness. In conclusion, biocontrol attempts using urban green spaces may have unexpected outcomes, such as resulting in larger pest organisms.

Anti-Inflammatory and Antimicrobial Effects of Eucalyptus spp. Essential Oils: A Potential Valuable Use for an Industry Byproduct.

In Brazil, the use of Eucalyptus is focused on the production of wood or pulp for the paper industry but without any general recovery of waste, with leaves and branches being left on the ground. One possibility is to use these residues as raw materials in the production of industrially relevant and value-added compounds such as essential oil. The aim of the present study was to investigate the chemical composition, yield, anti-inflammatory/antinociceptive activities, and acute toxicity in mice, as well as the antimicrobial effects of essential oils from the leaves of 7 varieties of Eucalyptus and hybrids against Escherichia coli, Staphylococcus aureus, and Candida albicans. The extraction of oils was carried out using hydrodistillation, and they were analyzed by gas chromatography coupled to mass spectrometry. Urocam and Grancam were the plants that obtained the highest oil yield, with yields of 3.32 and 2.30%, respectively. The main chemical components identified in these plants were 1.8 cineole and α-pinene. The antinociceptive effect of the 7 oils (50 mg/kg, p.o.) was initially assessed in the acetic acid-induced writhing test. In this assay, a significant (p < 0.05) antinociceptive/anti-inflammatory effect was observed from 4 tested essential oils (E. benthamii, E. saligna, and the hybrids Urocam and Grancam) when compared to the vehicle-treated group. This effect was then confirmed in the formalin-induced paw licking test. No toxicological effects or alterations were observed in motor coordination after the administration of the studied oils to the animals. In the antimicrobial evaluation, the seven essential oils inhibited the growth of S. aureus, E. coli, and C. albicans at different concentrations. Collectively, these results demonstrate that the essential oil from the leaves and branches of Eucalyptus species and varieties present potential biomedical applications and represent a source of antimicrobial and/or anti-inflammatory compounds.

Biological Properties of Aloysia gratissima (Gillies & Hook.) Tronc. (Verbenaceae).

Aloysia gratissima is a plant native to America, with applications in folk medicine for a wide range of diseases, such as bronchial infections, lung disorders, nervous system disorders (depression, anxiety), and inflammatory processes, among others. However, investigations about this species and its biological actions are still scarce. This literature review was carried out using articles published in the past 30 years on the PubMed, SciELO, and Web of Science platforms, with the focus on the method of extraction, chemical composition, and clinical and preclinical studies on the pharmacological properties of A. gratissima. We noticed that the main constituents of A. gratissima are guaiol, pinocamphone, ß-pinene, and 1,8-cineole. Additionally, preclinical studies reveal that A. gratissima extracts present antidepressant, anti-inflammatory, antinociceptive, antibacterial, antifungal, and virucidal effects. The results also demonstrate that there is a greater interest on the part of researchers from 2012 onwards in studying A. gratissima extracts with potential for possible new drugs.

Characterization of the chemical profile and the effects of ethanolic extracts of Maytenus ilicifolia Mart. ex Reissek on glucose metabolism in normal hyperglycemic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Maytenus ilicifolia Mart. ex Reissek, Celastraceae, is popularly known as "espinheira-santa" and used to treat pathologies related to the stomach. However, in popular culture, this species has also been used to treat other disorders such as diabetes, but without scientific evidence, requiring more phytochemical and pharmacological studies on the plant. AIM OF THE STUDY: This work aims to investigate the anti-hyperglycemic potential of ethanolic extracts obtained from leaves from two different accessions of Maytenus ilicifolia (MIA and MIB) in normal hyperglycemic rats. MATERIALS AND METHODS: The animals were divided into different experimental groups: normal hyperglycemic (negative control); MIA (treatment of Maytenus ilicifolia extract from access 116); MIB (treatment with Maytenus ilicifolia extract from access 122; and glipizide (positive control). At 30 min after treatment, all animals received glucose overload orally. Blood collection occurred at different periods for the assessment of blood glucose (0, 60, 90 and 210 min after treatment) and at the end of the experiment blood was collected through cardiac puncture and the liver, muscle, pancreas and intestine were dissected for further analysis. RESULTS: Chromatographic analysis identified oleic and palmitic acid as the most common constituents, and both extracts of Maytenus ilicifolia caused a reduction in blood glucose levels within 60 min after administration of glucose overload when compared to the normal hyperglycemic group. No significant changes were observed in hepatic and muscular glycogen levels, plasma insulin concentration and disaccharidases activity with none of the extracts in the model employed. However, hyperglycemic rats treated with the extracts showed a marked increase in triglyceride and HDL cholesterol levels. CONCLUSIONS: Our data suggest that Maytenus ilicifolia extracts from different locations showed differences in chemical composition which did not reflect significant differences in the results of biological tests. In addition, it was possible to conclude that the treatment with Maytenus ilicifolia had a discreet anti-hyperglycemic effect; however, it was not possible to identify the responsible mechanism, being necessary, therefore, new studies using different technologies in order to determine the possible mechanisms of action of the extract.

Eugenia umbelliflora mediated reduction of silver nanoparticles incorporated into O-carboxymethylchitosan/y-Fe2O3: Synthesis, antimicrobial activity and toxicity.

The purpose of this study was to synthesize a new magnetic material with antimicrobial properties, incorporated into a biopolymer and containing silver nanoparticles (Ag NP) prepared extract of Eugenia umbelliflora as a reducing agent. Silver nanoparticles incorporated into magnetic nanocomposite O-carboxymethylchitosan/y-Fe2O3/Ag0 (CMAgE) composite were synthesized using an extract of E. umbelliflora. The antimicrobial activity of the pathogenic microorganism is reported here. The synthesized nanoparticles were also characterized, and quantified by Ag analysis. The minimum inhibitory concentrations (MIC) of CMAgE against Staphylococcus aureus, Escherichia coli, and Candida albicans were 16.5, 1000 and 500 µg/mL, respectively. The results show that these materials have significant synergistic effect on each other. The potential phytotoxic effect of the nanocomposites was evaluated using Cucumis sativus seeds. The positive values for seedling elongation inhibition (SEI) show that CMAgE and methanol extract of Eugenia umbelliflora (Eug) cause growth inhibition at a concentration of 1000 mg/L. The germination index (GI) values of 40% and 80% at 1000 mg/L, for CMAgE and Eug, respectively, showed inhibition of germination. CMAgE and Eug showed cytotoxic effects against Artemia salina nauplii, with LC50 values of 72.5 µL/mL and < 5.0 µL/mL respectively, after 48 h.

Ractopamine hydrochloride induces behavioral alterations and oxidative status imbalance in zebrafish.

The occurrence of ractopamine (RAC) hydrochloride in water bodies is of significant concern due to its ecological impacts and toxicity to humans. RAC hydrochloride is a ß-adrenergic agonist drug used as a feed additive to (1) improve feed efficiency, (2) rate of weight gain, and (3) increase carcass leanness in animals raised for their meat. This drug is excreted by animals in urine and introduced into the environment affecting nontarget organisms including fish. In wastewater released from farms, RAC concentrations were detected from 0.124 µg/L to 30.1 µg/L, and in levels ranging from 1.3 × 10-5 to 5.4 × 10-4 µg/L in watersheds. The aim of this study was to examine the effects of exposure to RAC at 0.1, 0.2, 0.85, 8.5, or 85 µg/L dissolved in water on behavior and oxidative status in adult zebrafish. At 0.85 µg/L, RAC treatment increased exploratory behavior of zebrafish; while at 8.5 µg/L, decreased locomotor and exploratory activities were noted. With respect to oxidative stress biomarkers, results showed that RAC at 0.2 µg/L induced lipid peroxidation and elevated total thiol content in zebrafish brain. All drug tested concentrations produced a fall in nonprotein thiol content. Finally, RAC at 0.85, 8.5, or 85 µg/L increased catalase enzyme activity. Our results demonstrated that the exposure to RAC induced behavioral alterations and oxidative stress in zebrafish.

Antidepressant-Like and Antioxidant Effects of Plinia trunciflora in Mice.

The jaboticaba tree, Plinia trunciflora (O. Berg) Kausel, is popularly named "jabuticabeira" in Brazil and is used in folk medicine to treat diabetes and chronic inflammation of the tonsils, but studies evaluating the central effects of this species are limited. This study evaluated the antidepressant-like and antioxidant effects of P. trunciflora (PT) aqueous extract, in which five different anthocyanins were identified. PT showed significant ferric-reduction power and DPPH radical scavenging activity in vitro and reduced lipid peroxidation both in vitro and ex vivo. At the behavioural level, PT (400 and 800 mg/kg, i.p.) dose-dependently reduced immobility time in the tail suspension test in Swiss male mice. The identification of bioactive compounds accompanied by the in vitro and ex vivo antioxidant activity of PT suggests that these activities might be related to the antidepressant-like activity of P. trunciflora.

Pharmacological and phytochemical evaluation of Adiantum ceneatum growing in Brazil.

This work describes the phytochemical analysis and analgesic activity of a non polar fraction obtained from Adiantum cuneatum grown in Brazil. The results showed that the hexane fraction as well as two pure compounds, identified as filicene (1) and filicenal (2), given intraperitoneally, exhibited potent analgesic activity when evaluated in two models of pain in mice, writhing test and formalin-induced pain. Compound 1 presented a calculated ID50 value of 19.5 micromol/kg body weight, when evaluated in writhing test, being about 7-fold more active than some reference drugs, like as acetyl salicylic acid and acetaminophen. It also inhibited both phases (neurogenic and inflammatory) of the formalin test at 10 mg/kg (24 micromol/kg). The chemical composition of the plant grown in Brazil is similar to that grown in other countries. The results confirm and justify the popular use of this plant for the treatment of dolorous processes.