Cytogenotoxicity evaluation of heavy metals detected in extracts and infusion of Baccharis trimera, potential bioaccumulator plant.

Heavy metals (HMs) are natural components of the Earth's crust that might originate from natural and anthropogenic sources. In excess quantities, the presence of these metals is harmful for both environment and human health. Taking this into account, various investigators examined bioaccumulator species in order to reduce environmental toxicity, among these Baccharis trimera. Therefore, the present study aimed to determine the capacity of B. trimera to bioaccumulate HMs and assess consequent cytogenotoxicity following exposure. B. trimera vegetative parts were collected from two groups (1) control, in which plants were cultivated in soil exposed to distilled water, and (2) exposed, in which plants were cultivated in soil exposed to HMs including manganese (Mn), iron (Fe), lead (Pb), copper (Cu), cobalt (Co), zinc (Zn), and chromium (Cr). HMs were quantified in cultivation soil and extracts (aqueous and ethanolic) as well as infusion of B. trimera vegetative parts. Root lengths and cytogenotoxic effects were determined using Allium cepa test. Results demonstrated that all HMs studied were absorbed and bioaccumulated by B. trimera. Root lengths were decreased when exposed to ethanolic extract of B. trimera cultivated in soil exposed to HMs solution, which was the extract that exhibited the highest cytogenotoxicity values. Thus, data demonstrated that B. trimera might serve as a bioaccumulator for the reduction of environmental toxicity associated with the presence of certain HMs.

Effect of the Proximity to the Quintero-Puchuncaví Industrial Zone on Compounds Isolated from Baccharis macraei Hook. & Arn: Their Antioxidant and Cytotoxic Activity.

Baccharis macraei Hook. & Arn (Asteraceae), commonly known as Vautro, is found in the coastal areas of central-southern Chile, including the industrial zone of Quintero-Puchuncaví, known for the contamination of its soils with heavy metals, which together with other factors generate abiotic stress in plant species, against which they present defensive mechanisms. For this reason, the objective was to evaluate the effect of abiotic stress generated by the proximity of B. macraei to the industrial complex by assessing the physiological and metabolic states reported by the extracts and compounds isolated from the species, as well as the photosynthetic capacity, metal content and production, and antioxidant activity and cytotoxicity against tumorigenic cell lines of the phytoconstituents. To this end, B. macraei was collected at two different distances from the industrial complex, observing that the closer the species is, the greater the concentration of copper in the soil, generating a decrease in the rate of electron transport in situ, but an increase in antioxidant activity with low cytotoxicity. This activity could be due to the presence of flavonoids such as Hispidulin, Cirsimaritina, and Isokaempferida, as well as monoterpenes, oxygenated and non-oxygenated sesquiterpenes identified in this study.

Antimicrobial Activity and Phytochemical Characterization of Baccharis concava Pers., a Native Plant of the Central Chilean Coast.

Few sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of Baccharis concava Pers. (sin. B. macraei), a shrub found in the first line and near the Pacific coast. B. concava has been traditionally used by indigenous inhabitants of today's central Chile for its medicinal properties. Few reports exist regarding the phytochemistry characterization and biological activities of B. concava. A hydroalcoholic extract of B. concava was prepared from leaves and small branches. Qualitative phytochemical characterization indicated the presence of alkaloids, steroids, terpenoids, flavonoids, phenolic, and tannin compounds. The antimicrobial activity of this extract was assessed in a panel of microorganisms including Gram-positive bacteria, Gram-negative bacteria, and pathogenic yeasts. The extract displayed an important antimicrobial effect against Gram-positive bacteria, Candida albicans, and Cryptococcus neoformans but not against Gram-negatives, for which an intact Lipopolysaccharide is apparently the determinant of resistance to B. concava extracts. The hydroalcoholic extract was then fractionated through a Sephadex LH-20/methanol-ethyl acetate column. Afterward, the fractions were pooled according to a similar pattern visualized by TLC/UV analysis. Fractions obtained by this criterion were assessed for their antimicrobial activity against Staphylococcus aureus. The fraction presenting the most antimicrobial activity was HPLC-ESI-MS/MS, obtaining molecules related to caffeoylquinic acid, dicaffeoylquinic acid, and quercetin, among others. In conclusion, the extracts of B. concava showed strong antimicrobial activity, probably due to the presence of metabolites derived from phenolic acids, such as caffeoylquinic acid, and flavonoids, such as quercetin, which in turn could be responsible for helping with wound healing. In addition, the development of antimicrobial therapies based on the molecules found in B. concava could help to combat infection caused by pathogenic yeasts and Gram-positive bacteria, without affecting the Gram-negative microbiota.

Ethnobotanical knowledge on native Brazilian medicinal plants traditionally used as anthelmintic agents - A review.

Intestinal helminthiasis is a neglected disease that affects a significant portion of the global population, specifically in developing countries, where medicinal plants are widely used for therapeutic purposes. With the purpose to identify the native species used in traditional Brazilian medicine for the management of helminthiasis, ethnopharmacological books edited in Brazil documenting the folk use of medicinal plants were analyzed. The native species cited in at least three studies were selected, and bibliographic research was performed using electronic databases to identify their scientifically validated anthelmintic properties. The search retrieved 133 native species belonging to 88 genera and 43 families from all six Brazilian biomes. Fabaceae (14 Genera and 25 Species) and Asteraceae (7 Genera and 8 Species) were the most frequently cited families. The most reported native species were Baccharis crispa Spreng., Hymenaea courbaril L., Senna occidentalis (L.) Link, Carapa guianensis Aubl., Stachytarpheta cayennensis (Rich.) Vahl, Annona glabra L., Hymenaea stigonocarpa Mart. ex Hayne, Spigelia anthelmia L., Simarouba versicolor A.St.-Hil. and Anacardium occidentale L. Bark (19%) and leaves (17%) were the most commonly used plant parts, and decoction (27%) was the most preferred method of preparation. Evidence of the anthelmintic properties of most species was confirmed using in vitro assays for key human and animal parasites, including Haemonchus contortus, Hymenolepis diminuta, Schistosoma mansoni and Trichostrongylus spp. The species S. alata, S. occidentalis, A. occidentale, and S. anthelmia have been the subject of many biological studies, supporting their use as vermicides. The overall results obtained in this review revealed that Brazil is rich in traditional herbal medicines used to manage helminthiasis; however pharmacological investigations are lacking to confirm their therapeutic properties. Thus, this study could serve as a baseline to validate their use and encourage further clinical investigation of their vermifuge potential.

Antibiofilm Activity of Invasive Plants against Candida albicans: Focus on Baccharis halimifolia Essential Oil and Its Compounds.

The extracts of five invasive plants were investigated for antifungal and antibiofilm activities against Candida albicans, C. glabrata, C. krusei, and C. parapsilosis. The antifungal activity was evaluated using the microdilution assay and the antibiofilm effect by measurement of the metabolic activity. Ethanol and ethanol-water extracts of Reynoutria japonica leaves inhibited 50 % of planktonic cells at 250 µg mL-1 and 15.6 µg mL-1 , respectively. Ethanol and ethanol-water extracts of Baccharis halimifolia inhibited >75 % of the mature biofilm of C. albicans at 500 µg mL-1 . The essential oil (EO) of B. halimifolia leaves was the most active (50 % inhibition (IC50 ) at 4 and 74 µg mL-1 against the maturation phase and 24 h old-biofilms of C. albicans, respectively). Oxygenated sesquiterpenes were the primary contents in this EO (62.02 %), with ß-caryophyllene oxide as the major component (37 %). Aromadendrene oxide-(2), ß-caryophyllene oxide, and (±)-ß-pinene displayed significant activities against the maturation phase (IC50 =9-310 µ mol l-1 ) and preformed 24 h-biofilm (IC50 =38-630 µ mol l-1 ) of C. albicans with very low cytotoxicity for the first two compounds. C. albicans remained the most susceptible species to this EO and its components. This study highlighted for the first time the antibiofilm potential of B. halimifolia, its EO and some of its components.

Evaluation of Anti-Trypanosoma cruzi Activity of Chemical Constituents from Baccharis sphenophylla Isolated Using High-Performance Countercurrent Chromatography.

Endemic in 21 countries, Chagas disease, also known as American Trypanosomiasis, is a neglected tropical disease (NTD) caused by the protozoan parasite Trypanosoma cruzi. The available drugs for the treatment of this disease, benznidazole and nifurtimox, are outdated and display severe side effects. Thus, the discovery of new drugs is crucial. Based on our continuous studies aiming towards the discovery of natural products with anti-T. cruzi potential, the MeOH extract from aerial parts of Baccharis sphenophylla Dusén ex. Malme (Asteraceae) displayed activity against this parasite and was subjected to high-performance countercurrent chromatography (HPCCC), to obtain one unreported syn-labdane diterpene - sphenophyllol (1) - as well as the known compounds gaudichaudol C (2), ent-kaurenoic acid (3), hispidulin (4), eupafolin (5), and one mixture of di-O-caffeoylquinic acids (6-8). Compounds 1-8 were characterized by analysis of nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. When tested against trypomastigote forms, isolated labdane diterpenes 1 and 2 displayed potent activity, with EC50 values of 20.1 µM and 2.9 µM, respectively. The mixture of chlorogenic acids 6-8, as well as the isolated flavones 4 and 5, showed significant activity against the clinically relevant amastigotes, with EC50 values of 24.9, 12.8, and 2.7 µM, respectively. Nonetheless, tested compounds 1-8 displayed no cytotoxicity against mammalian cells (CC50 > 200 µM). These results demonstrate the application of HPCCC as an important tool to isolate bioactive compounds from natural sources, including the antitrypanosomal extract from B. sphenophylla, allowing for the development of novel strategic molecular prototypes against tropical neglected diseases.

Disinfectant activities of extracts and metabolites from Baccharis dracunculifolia DC.

The concern regarding the harm caused by biocides to human health has been increasing over the years, making the natural products an alternative to less toxic and more efficient biocides. Therefore, this paper reports the investigation of the disinfectant potential of extracts and isolated compounds from Baccharis dracunculifolia. For this purpose, extracts of aerial parts (BD-C), tricomial wash (BD-L) and roots (BD-R) of B. dracunculifolia were obtained by maceration. The extracts were submitted to different chromatographic techniques, including high-speedy countercurrent chromatography (HSCCC) furnishing nine isolated compounds. The extracts and isolated compounds were evaluated regarding their antimicrobial activity by the broth microdilution method, according to the Clinical and Laboratory Standards Institute, and regarding their sanitizing activity according to Standard Operating Procedure No. 65·3210·007 (INCQS, 2011), developed by the National Institute for Quality Control in Health (INCQS) - Oswaldo Cruz Foundation (FIOCRUZ). In the antimicrobial evaluation the BD-C extract showed minimum inhibitory concentration (MIC) values of 200 and 100 µg/ml against Staphylococcus aureus and Tricophyton mentagrophytes, respectively. BD-L extract showed MIC value of 200 µg/ml against S. aureus. The isolated compounds caffeic acid (MBC 2·22 µmol l-1 ), ferulic acid (MBC 2·06 µmol l-1 ) and baccharin (MBC 0·27 µmol l-1 ) showed significant inhibitory activity against S. aureus. All B. dracunculifolia isolated compounds were active with exception of aromadrendin-4´-O-methyl-ether for T. mentagrophytes. Additionally, isosakuranetin was active against Salmonella choleraesuis (MIC 1·4 µmol l-1 ). Regarding the sanitizing activity, the hydroalcoholic solution containing 0·2% of B. dracunculifolia extract in 40°GL ethanol was effective in eliminating the microbial contamination on all carrier cylinders and against all microorganisms evaluated in the recommended exposure time of 10 min. Therefore, B. dracunculifolia has potential for the development of sanitizing agents to be used in hospitals, food manufactures and homes.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

Selective cytotoxicity of ent-kaurene diterpenoids isolated from Baccharis lateralis and Baccharis retusa (Asteraceae).

This study presents the cytotoxic activity evaluation of the natural diterpenes ent-kaurenoic acid (1) and its 15ß-hydroxy (2), 15ß-senecioyloxy (3), and 15ß-tiglinoyloxy (4) derivatives, isolated from Brazilian native plants, Baccharis retusa and B. lateralis (Asteraceae). Using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay, it was observed that compound 1 displayed in vitro activity towards the aggressive MDA-MB-231 adenocarcinoma cell line and reduced toxicity against MCF-10A nontumorigenic epithelial cells, indicating expressive selectivity. On the contrary, compounds 2-4 exhibited reduced toxicity and selectivity in both tested cell lines. Based on the chemical structures of compounds 1-4, it is suggested that the presence of additional functional groups at the C-15 position-a hydroxyl group in compound 2 and isomeric isoprene units in compounds 3 and 4-might be responsible for the reduction in the potential/selectivity. In silico studies show, for compounds 1-4, good predictions regarding bioavailability and ADME (absorption, distribution, metabolism, and excretion) properties as well as no alerts for PAINS (pan-assay structures interference). In conclusion, ent-kaurenoic acid (1), a common diterpenoid isolated in high amounts from different plants belonging to the Baccharis genus, has been shown to be a promising cytotoxic agent against an aggressive adenocarcinoma cell line (MDA-MB-23) and, if well exploited, could be used as a scaffold in the development of molecular prototypes for the treatment of breast cancer.

Alternative method for microenzymatic inhibition activities monitoring from Baccharis trimera extracts by CZE-UV.

INTRODUCTION: Capillary zone electrophoresis with direct UV detection (CZE-UV) was used to investigate the hypothesis about the extract of Baccharis trimera enzymatic activities as an analytical approach to monitoring the phenomenon. OBJECTIVE: The aim of this work was to investigate enzymatic bioactivities of the hydroalcoholic and infusion extracts of B. trimera through screening evaluation of the inhibition of the enzymes acetylcholinesterase (AChE) and α-glycosidase (α-GLY). METHOD: An alternative approach using CZE-UV to hydroalcoholic and infusion extracts of B. trimera monitoring was applied to evaluate the inhibition ability of the enzymes AChE and α-GLY. The result of the reaction of acetylthiocholine (AThCh) with AChE was thiocholine (TCh) and acetic acid, and from the amount of TCh generated, the AChE inhibition was calculated. For the inhibition study of the two enzymes, the reactions of the extracts were optimised to be performed in situ, inside the capillary column, and the introduction of the solutions was performed through ordered sequential plug injections. RESULTS: Samples extracted with 70% ethanol presented 7.80% inhibition for AChE and 0.51% for α-GLY, while samples extracted with 96% ethanol resulted in 6.89% inhibition for AChE and no inhibition activity for α-GLY. CONCLUSION: In the present work, the potentialities of CZE-UV for the study of hydroalcoholic and infusion extracts of B. trimera were demonstrated. The experimental results were useful for the calculation of the percentage of the inhibition activities of the AChE and α-GLY enzymes.

In Vitro Pharmacological Screening of Essential Oils from Baccharis parvidentata and Lippia origanoides Growing in Brazil.

In this study, the in vitro antimicrobial, antiparasitic, antiproliferative and cytotoxic activities of essential oil from Baccharis parvidentata Malag. (EO-Bp) and Lippia origanoides Kunth (EO-Lo) were explored. The relevant effects were observed against the parasitic protozoans Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei and Leishmania amazonensis (ranging 0.6 to 39.7 µg/mL) and malignant MCF-7, MCF-7/HT, 22Rv1, and A431 cell lines (ranging 6.1 to 31.5 µg/mL). In parallel, EO-Bp showed better selective indexes in comparison with EO-Lo against peritoneal macrophages from BALB/c mice and MRC-5 cell line. In conclusion, EO-Lo is known to show a wide range of health benefits that could be added as another potential use of this oil with the current study. In the case of EO-Bp, the wide spectrum of its activities against protozoal parasites and malignant cells, as well as its selectivity in comparison with non-malignant cells, could suggest an interesting candidate for further tests as a new therapeutic alternative.

Phytochemical characterization and inhibition of Candida sp. by the essential oil of Baccharis trimera (Less.) DC.

This study aimed to investigate the chemical composition and antifungal potential of the essential oil of Baccharis trimera (Less.) DC. against Candida strains. The half maximal inhibitory concentration (IC50) was assessed by the microdilution method using the essential oil at a concentration range of 8192 to 8 µg/mL. The minimum fungicide concentration (MFC) was determined by subculture in solid medium. The ability of the essential oil to modulate the activity of antifungals was determined in wells treated simultaneously with the oil at a subinhibitory concentration (MFC/16) and fluconazole (FCZ). The fungal morphology was analyzed by microscopy. Gas chromatography coupled with mass spectrometry (GC/MS) was used to identify the chemical composition. The essential oil presented an CI50 of 11.24 and 1.45 µg/mL, which was found to potentiate the effect of FCZ against Candida albicans. On the other hand, this combined treatment resulted in antagonism against Candida tropicalis and no evident modulation against Candida krusei was observed. The essential oil significantly inhibited hyphae growth. However, with a MFC ≥ 16,384 µg/mL, it is assumed that it has a fungistatic action. The antifungal properties demonstrated in this study might be related to the presence of sesquiterpenes and monoterpenes, and the interaction between them. In conclusion, Baccharis trimera showed promising anti-Candida effects, in addition to potentiating the activity of FCZ against Candida albicans, affecting its morphological transition. Therefore, this species constitutes a source of chemical compounds with the potential to be used in the combat of fungal infections.

Hepato- and cardioprotective effects of Baccharis trimera (Less.) DC. against multiple risk factors for chronic noncommunicable diseases.

Cardiovascular diseases are associated with high morbidity and mortality worldwide and have several risk factors, including dyslipidemia, smoking, and hypertension. Studies have evaluated isolated risk factors in experimental models of cardiovascular disease, but few preclinical studies have assessed associations between multiple risk factors. In the present study, hypertensive Wistar rats (Goldblatt 2K1C model) received a 0.5% cholesterol diet and were exposed to tobacco smoke for 8 weeks. During the last 4 weeks, the animals were treated with vehicle, an ethanol-soluble fraction of B. trimera (30, 100, and 300 mg/kg), or simvastatin + enalapril. A group of normotensive, non-dyslipidemic, and non-smoking rats was treated with vehicle. The levels of aspartate aminotransferase, alanine aminotransferase, urea, creatinine, and hepatic and fecal lipids, blood pressure, and mesenteric arterial bed reactivity were evaluated. Cardiac, hepatic, and renal histopathology and tecidual redox state were also investigated. Untreated animals exhibited significant changes in blood pressure, lipid profile, and biomarkers of heart, liver, and kidney damage. Treatment with B. trimera reversed these changes, with effects that were similar to simvastatin + enalapril. These findings suggest that B. trimera may be promising for the treatment of cardiovascular and hepatic disorders, especially disorders that are associated with multiple risk factors.

Relationship between Baccharis dracunculifolia DC. and B. microdonta DC. (Asteraceae) by Their Different Seasonal Volatile Expression.

Baccharis dracunculifolia DC. and Baccharis microdonta DC. (Asteraceae) are woody species morphologically similar growing in Uruguay, where not taxonomists people often confuse them in field conditions. As the essential oil of B. dracunculifolia ('vassoura' oil) is highly prized by the flavor and fragrance industry, the correct differentiation of the two species is a key factor in exploiting them profitably and reasonably. To differentiate both Baccharis species, in this work their volatile expression profiles were studied as an alternative tool to determine authenticity and quality. Volatile organic compounds (VOCs) were monthly extracted during an entire year from aerial parts of wild populations by simultaneous distillation extraction (SDE), and studied by gas chromatography/mass spectrometry (GC/MS; identification) and conventional gas chromatography (GC-FID; component abundances determination). Enantioselective gas chromatography/mass spectrometry (Es-GC/MS) was applied in the search of parameters able to ensure genuineness of each species extract. Qualitative VOCs profiles were found to be similar for both species, being ß-pinene, limonene, spathulenol, caryophyllene oxide, and viridiflorol the main components. However, the abundance of those VOCs were two to ten times higher in B. dracunculifolia than in B. microdonta during the year of study. These Baccharis spp. showed species-specific patterns of VOCs expression according to the seasonality, and interestingly, oxygenated compounds (trans-pinocarveol and myrtenal) increased their abundances at full-flowering stages. The enantiomeric distribution of selected monoterpenes (α- and ß-pinenes, limonene, linalool, terpinen-4-ol, and α-terpineol) presented differential values for both Baccharis spp., meaning that Es-GC might be a useful tool for differentiating chemically both species in Uruguay for genuineness determination purposes.

Chemical Constituents from Aerial Parts of Baccharis sphenophylla and Effects against Intracellular Forms of Trypanosoma cruzi.

The hexane extract from aerial parts Baccharis sphenophylla Dusén ex Malme (Asteraceae) displayed activity against amastigote forms of Trypanossoma cruzi and was subjected to chromatographic steps to afford one unreported - 7α-hydroxy-ent-abieta-8(14),13(15)-dien-16,12ß-olide (1) and three known diterpenes - ent-kaur-16-en-19-oic acid, (2), grandifloric acid (3), and 15ß-tiglinoyloxy-ent-kaur-16-en-19-oic acid (4), two sesquiterpenes - spathulenol (5) and oplopanone (6) - as well as hexacosyl p-coumarate (7). Isolated compounds were characterized by NMR and ESI-HR-MS spectra and were evaluated in vitro for activity against amastigote forms of the parasite T. cruzi - the relevant clinical form in the chronic phase of Chagas disease. In addition, the activity of compounds 1-7 against NCTC cells was evaluated. Compounds 1 and 7 showed effectiveness with EC50 values of 21.3 and 16.9 µM, respectively. Both compounds also exhibited reduced toxicity against NCTC cells (CC50 >200 µM) with SI values higher than 9.4 and 11.9. Obtained results suggest that the new ent-abietane diterpene 1 and alkyl coumarate 7 could be used as prototypes for the development of novel and selective semisynthetic derivatives against intracellular forms of T. cruzi.

A novel fast-vegetative propagation technique of the pioneer shrub Baccharis linearis on mine tailings by adding compost.

Interest in Baccharis linearis has increased as an alternative for assisted phytostabilization due to its spontaneous colonization of tailings dumps. The search for a novel fast-vegetative propagation technique to accelerate its coverage on mine tailings is a promising research area for sustainable mine closure plans. In this study, we determined the optimal proportion of compost and tailings as growing media to promote fast B. linearis propagation through a compound layering technique. The assessed growing substrates were: 100% tailings, 70% tailings + 30% compost, and 50% tailings + 50% compost. After 84 days of growth, the change in number and height of layering branches, root and shoot dry mass, percentage of ground coverage, and substrate chemical properties were assessed. The main results showed that compound layering of B. linearis is possible with compost addition. The growth of new roots and layering branches was significantly improved by either 30% or 50% compost addition into tailings, due to chemical improvements of substrate (higher nutrients and pH and decreased copper bioavailability). The study confirms that the compound layering of B. linearis may be an effective and novel technique for speeding the reclamation of post-operative mine tailings, which is improved by the incorporation of compost.

Characterization and antibacterial activity of the essential oil obtained from the leaves of Baccharis coridifolia DC against multiresistant strains.

Essential oils are secondary metabolites with immense pharmacological potential.These substances are abundantly produced by plants of the family Asteraceae, such as Baccharis coridifolia. Previous studies have demonstrated that this species has pharmacological properties that make it a promising source of new antibacterial agents. Therefore, the present study aimed to evaluate the antibacterial and antibiotic-modulating activity of Baccharis coridifolia essential oil against multidrug-resistant (MDR) strains. The phytochemical analysis was carried out by gas chromatography coupled to Mass Spectroscopy (GC/MS), and realized the Minimum Inhibitory Concentation (MIC) and antibiotic-modulation from the microdilution method in 96-well plates. It was revealed the presence of germacrene D (23.7%), bicyclogermacrene (17.1%), and (E)-caryophyllene (8.4%) as major components. The minimum inhibitory concentration of essential oil against strains of Pseudomonas aeruginosa (512 µg/mL) and Staphylococcus aureus (128 µg/mL) demonstrated clinically relevant antibacterial activity. In addition, the combination of subinhibitory doses of the oil with conventional antibiotics showed synergism, indicating potentiation of the antibacterial effect. In conclusion, the essential oil of Baccharis coridifolia (EOBc) presented antibacterial and antibiotic-modulating activities that place this species as a source of molecules useful in the fight against bacterial resistance.

15ß-Senecioyl-oxy-ent-kaur-16-en-19-oic Acid, a Diterpene Isolated from Baccharis lateralis, as Promising Oral Compound for the Treatment of Schistosomiasis.

Praziquantel is the only available drug to treat schistosomiasis, and therefore, urgent studies must be performed to identify new anthelmintic agents. This study reports the anthelmintic evaluation of two related ent-kaurane diterpenes isolated from aerial parts of Baccharis lateralis (Asteraceae), ent-kaur-16-en-19-oic acid (1) and 15ß-senecioyl-oxy-ent-kaur-16-en-19-oic acid (2) against Schistosoma mansoni in vitro and in a murine model of schistosomiasis. Both compounds exhibited in vitro activity with lethal concentration 50% (LC50) values of 26.1 µM (1) and 11.6 µM (2) as well as reduced toxicity against human cell lines, revealing a good selectivity profile, mainly with compound 2 (selectivity index > 10). Compound 2 also decreased egg production and caused morphological alterations in the parasite reproductive system. In mice infected with S. mansoni, oral treatment with compound 2 at 400 mg/kg, the standard dose used in this model of schistosomiasis, caused a significant reduction in a total worm burden of 61.9% (P < 0.01). S. mansoni egg production, a key mechanism for both transmission and pathogenesis, was also markedly reduced. In addition, compound 2 achieved a significant reduction in hepatosplenomegaly. Therefore, the diterpene 15ß-senecioyl-oxy-ent-kaur-16-en-19-oic acid (2) has an acceptable cytotoxicity profile and is orally active in a murine schistosomiasis model.

The Role of Baccharis dracunculifolia and its Chemical Profile on Green Propolis Production by Apis mellifera.

The botanical source of Brazilian green propolis (BGP) is Baccharis dracunculifolia DC, which interacts not only with Apis mellifera, but also with galling insects. In the last decade, because of green propolis´ important biologic activities, the international demand for BGP overcame the production capacity, consequently, new approaches are required to increase this production. Hence, the understanding of the chemical ecology interactions of B. dracunculifolia with galls and bees in field conditions may provide insights to increase BGP's production. A "bee pasture" experiment aiming to better understand this plant-insect interaction was therefore performed. For that, 48 B. dracunculifolia individuals, being 24 females and 24 males, were cultivated and investigated for the following parameters: (1) phenolic and volatile compounds in both B. dracunculifolia leaves and green propolis, (2) environmental variables, (3) visiting rate by bees, (4) time of resin collection, and (5) number of galls. Regression analyses by independent linear mixed-effect models were run to correlate phenolic and volatile compounds concentration with the environmental and field variables. Significant differences in chemical profile and field variables were observed between male and female plants. Male plants showed higher infestation by galling insects while female plants showed higher number of visiting bees, time of resin collection and terpenes concentration, contributing to the differences observed in the field. The obtained results suggest that increasing the percentage of female B. dracunculifolia plants in the field may attract more bees and therefore enhance propolis production.

Exposure to essential oils and ethanol vapors affect fecundity and survival of two frugivorous fruit fly (Diptera: Tephritidae) pest species.

Plant-derived compounds can be an environmentally friendly alternative to synthetic pesticide use for pest management. Essential oils (EOs) in several plant families have been found to be toxic to various pest species of insects through topical application, ingestion, and as fumigants. Previous studies revealed that, among various environmentally friendly insecticides, the EOs of Baccharis dracunculifolia and Pinus elliottii and an ethanol extract of Solanum granulosoleprosum plus Ricinus communis, were toxic to Ceratitis capitata and Anastrepha fraterculus (Diptera: Tephritidae) when applied topically to pupae or when ingested by adults. Here, we aimed to examine the potentially toxic effects of these plant-derived compounds when these two pestiferous fruit fly species were exposed to their vapors. We also examined their fumigant effect on female fecundity and fertility and compared it with water and ethanol controls. Exposure of C. capitata and A. fraterculus sexually mature adults to volatiles and vapors of both B. dracunculifolia and P. elliottii EOs resulted in lower longevity (half-life), survivorship, and female fecundity than the water vapor control. Toxicity of C. capitata was greater for P. elliottii than for B. dracunculifolia while the reverse was true for A. fraterculus. Exposure to vapors of S. granulosoleprosum + R. communis (S + R) had no effect on longevity but reduced survivorship of adults of both species. Interestingly, exposure to vapors of S + R, 50% (v/v) and pure ethanol resulted in greater fecundity of females of both frugivorous fly species than the water control. By contrast, fertility (% egg hatch) was in all cases high (>85%) and not different than the water control. Exposure to ethanol vapors appears to have similar effects on frugivorous tephritids as those reported on saprophagous and frugivorous species of Drosophila, a novel finding that may have important practical implications.