Chemical characterization and antimicrobial activity of Baccharis vulneraria Baker essential oil against strains of microorganisms that cause cutaneous infections

Baccharis vulneraria Baker is used popularly for the treatment of skin infections. So, this study aimed investigate the antimicrobial activity and chemical characterization of the essential oil (EO) against microorganisms that cause cutaneous infections. The EO was analyzed by GC-MS. The antimicrobial test was performed using the serial microdilution method, and the antimicrobial activity was determined by the minimum inhibitory concentration against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Trichophyton interdigitale, Trichophyton rubrum, Fusarium solani and Fusarium oxysporum within the 32-0.0625 mg/mL concentration range. Were identified 31 EO compounds. Its major compounds are bicyclogermacrene, trans-cadin-1,4-diene, β-caryophyllene, and germacrene A. EO showed antifungal action against T. rubrum and T. interdigitale (2 and 4 mg/mL MIC, respectively). The growth of C. albicans, at 4 mg/mL, decreased by 50% compared to control. The oil had no significant potential for other microorganisms at the selected concentrations.

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.

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.

Changes in phenolic profile and anti-inflammatory activity of Baccharis beebread during gastrointestinal digestion/intestinal permeability in vitro

Knowledge about the fate of beebread bioactive compounds throughout the human gastrointestinal tract are scarce. The present study aimed at assessing the effects of gastrointestinal digestion followed by intestinal permeability in vitro on phenolic profile and anti-inflammatory activity of Baccharis beebread. Palynological analysis confirmed the beebread is predominantly composed by pollen grains from Baccharis species, which are endemic in south and southeast Brazil. Flavonols and phenylamides were found in beebread hydroalcoholic extract by HPLC-ESI-QTOF-MS analysis. Moreover, simulated digestion lead to compounds' breakage, releasing both aglycones from glycosylated flavonols and p-coumaric acid, but not caffeic acid from phenylamides. Only spermidines crossed the Caco-2 cell monolayer, possibly due to spermine oxidation. Free p-coumaric acid was released after digestion, and epithelial transport. Concomitantly, NF-κΒ activation and TNF-α level was decreased by beebread even after Caco-2 transport, which indicates spermidines conjugated with p-coumaric acid may be bioavailable compounds with anti-inflammatory activity.

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.

Ethnomedicinal uses, phytochemistry, and pharmacological relevance of Justicia procumbens (Oriental Water Willow) - A promising traditional plant

ETHNOPHARMACOLOGICAL RELEVANCE

Justicia procumbens L. (JP) (Oriental Water Willow, Shrimp plant, Acanthaceae) is a herbaceous plant that is commonly found in India, Taiwan, Australia, Southern China, Vietnam, and Korea. The plant has been primarily used to treat fever, asthma, edema, cough, jaundice, urinary tract infection, and sore throat, as well as for snake bites and as a fish-killer. In the present review, the reported phyto-chemical, ethno-pharmacological, biological, and toxicological studies on J. procumbens were summarized. Special focus had been given to its reported lignans, regarding their isolation, characterization, quantitative estimation, and biosynthesis.

MATERIALS AND METHODS

A survey of the literature was done using assorted databases and publishers; Scopus, Sci-Finder, Web of Science, PubMed, GoogleScholar, ScienceDirect, Wiley, Taylors&Francis, Bentham, Thieme, and Springer.

RESULTS

Currently, 95 metabolites have been separated fromJ. procumbens. Lignans and their glycosides were reported as main phyto-constituents of J. procumbens. Various methods are mentioned for quantitative estimation of these lignans. These phyto-constituents possessed wide pharmacological effectiveness, such as antiplatelet aggregation, antimicrobial, antitumor, and antiviral.

CONCLUSIONS

Many of the stated effects are harmonious with the reported traditional uses of this plant. This data could further support J. procumbens's utilization as a herbal remedy and drug lead. However, further study of J. procumbens toxicity, as well as preclinical and clinical investigation is required to ensure the safe usage of J. procumbens.

Poisoning by Baccharis coridifolia in Early-Weaned Beef Calves: Pathological Study and New Macrocyclic Trichothecene Identification

This study investigated two outbreaks of spontaneous poisoning by Baccharis coridifolia (Asteraceae) in early-weaned beef calves in Tacuarembó, Uruguay. A total of 34 affected calves showed signs of salivation, anorexia, apathy, marked dehydration, and diarrhea. Deaths occurred 36-72 h after consumption and mortality varied from 37.5% to 43.3% for outbreak 1 and outbreak 2, respectively. The main pathological findings include diffuse severe necrosis of the prestomachs and lymphoid tissues. Ultrastructurally, epithelial cells of the rumen showed swelling, lysis of the organelles, degradation of intercellular attachments, and degradation of the nuclear chromatin. Using LC-MS with diagnostic fragmentation filtering, 56 macrocyclic trichothecenes including glycosyl and malonyl conjugates were identified. The total concentration of macrocyclic trichothecenes, including conjugates, was estimated to be 1.2 ± 0.1 mg/g plant material. This is the first report of these malonyl-glucose conjugates from Baccharis coridifolia.

Antinociceptive effect of cyclic and linear diterpenoids as new atypical agonists of κ-opioid receptors obtained from four species of the Baccharis genus, and vehiculated in nanometric niosomes

New natural analgesic compounds that act in KORs are important alternatives for potential therapeutical use in medicine. In this work, we report and compare here the antinociceptive activity displayed by cyclic and linear diterpenes, obtained from the genus Baccharis. The antinociceptive activities determined were relatively strong, in comparison whit morphine. The antinociceptive mechanism of action was made through naloxone administration (a non-selective antagonist of opioid receptors). The more active compounds were vehiculized successfully in niosomes at nanometric scale. The observed antinociceptive activity for Bartemidiolide oxide (BARTO), obtain from Baccharis artemisioides, was greater than Flabeloic acid dimer (DACD), the first compound isolated from Baccharis flabellata that was reported possessing antinociceptive effects. We also conducted docking calculations and molecular dynamics simulations, which suggested that the newly identified diterpenes might share the molecular action mechanism reported for Salvinorin A (SalA). Molecular simulations have allowed us to appreciate some subtle differences between molecular interactions of these ligands stabilizing their respective complexes; such information might be useful for designing and searching for new inhibitors of KORs.

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 β-caryophyllene oxide as the major component (37 %). Aromadendrene oxide-(2), β-caryophyllene oxide, and (±)-β-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.

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.

Ent-kaurane diterpenes isolated from n-hexane extract of Baccharis sphenophylla by bioactivity-guided fractionation target the acidocalcisomes in Trypanosoma cruzi

BACKGROUND

In the present work the bioactivity-guided fractionation of n-hexane extract from aerial parts of Baccharis sphenophylla (Asteraceae) against trypomastigote forms of Trypanosoma cruzi was performed.

PURPOSE

To evaluate the antitrypanosomal potential of diterpenes ent‑kaurenoic (1), grandifloric (2). and 15β-tiglinoyloxy‑ent-kaurenoic (3) acids, isolated from n-hexane extract from aerial parts of B. sphenophylla, and elucidate their mechanism of action against T. cruzi. METHODS/STUDY DESIGN: n-Hexane and MeOH extracts from aerial parts of B. sphenophylla were prepared and caused, respectively, 100% and 50% of death of trypomastigote forms of T. cruzi. Based on these results, the n-hexane extract was subjected to bioactivity-guided fractionation procedures to afford three related ent‑kaurane diterpenoids (1-3). Based on spectrofluorometric assays and flow cytometry analysis, the mechanism of action of compounds 1 and 3 was investigated.

RESULTS

Compounds 1 and 3, isolated from n-hexane extract from aerial parts of B. sphenophylla, showed potent activity against parasites with EC₅₀ values of 10.6 μM (SI > 18.8) and 2.4 μM (SI = 34.8), respectively. On the other hand, compound 2 was inactive against trypomastigotes. In mechanism of action studies using the fluorescent probe SYTOX Green, the plasma membrane permeability was unaltered after treatment with compounds 1 and 3, but compound 1 induced a depolarization of the plasma membrane electric potential (ΔΨp). No substantial alterations were observed in the mitochondria after treatment with compound 3, but a transient hyperpolarization of the mitochondrial membrane potential (ΔΨm) by compound 1. Despite the increased ATP levels induced by compounds 1 and 3, no alterations of ROS and Ca²⁺ levels were registered. However, both compounds promoted a time-dependent alkalinization of the acidocalcisomes, probably contributing to an osmotic imbalance of the cell. In silico physicochemical studies of compounds 1-3 suggested that lipophilicity and molecular complexity may play an important role in the antitrypanosomal activity. Moreover, no pan-assay interference compounds (PAINS) alerts were detected for compounds 1-3.

CONCLUSION

Obtained data indicated that the isolated ent‑kaurane diterpenes from n-hexane extract from aerial parts of B. sphenophylla, especially compound 3, could be considered interesting prototypes for further modifications aiming the discovery of new hits against 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.

Promising therapeutic use of Baccharis trimera (less.) DC. as a natural hepatoprotective agent against hepatic lesions that are caused by multiple risk factors

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis trimera (Less.) DC is a perennial subshrub, popularly known as "carqueja," that belongs to the Asteraceae family. Ethnobotanical studies indicate that this species is used for the treatment of diabetes and digestive and liver diseases. However, studies that sought to validate its popular use were conducted using ethanolic extracts of the plant, which does not reflect the ethnomedicinal use of this species in humans.

AIM OF THE STUDY

Non-alcoholic fatty liver disease (NAFLD) is characterized by triglyceride accumulation in the liver that can progress to cirrhosis and hepatocellular carcinoma. Because of the severity of this disease, less toxic and more effective therapeutic agents need to be developed. B. trimera may be a promising therapeutic alternative, but its activity against multiple risk factors for liver disease (e.g., smoking, dyslipidemia, and diabetes mellitus) has not been studied. The present study investigated the effects of an ethnomedicinal form of a B. trimera preparation in a rat model of NAFLD that is associated with multiple risk factors.

MATERIAL AND METHODS

Phytochemical analysis of the ethanolic soluble fraction of B. trimera extract was performed using ultra-performance liquid chromatography coupled to high-resolution mass spectrometry. Streptozotocin was used to induce diabetes in male Wistar rats. The rats received a 0.5% cholesterol-enriched diet and were exposed to cigarette smoke (9 cigarettes/day, 5 days/week, for 4 weeks). In the last 2 weeks, the animals were orally treated with vehicle (negative control group), B. trimera extract (30, 100, and 300 mg/kg), or insulin + simvastatin. One group of rats that was not exposed to these risk factors was also evaluated. Blood was collected for glucose, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) analysis. The liver and feces were collected for lipid quantification. The liver was additionally processed for histopathological analysis.

RESULTS

The model successfully induced NAFLD and increased levels of glucose, AST, and ALT in the negative control group. Treatment with the B. trimera extract (30 and 100 mg/kg) and insulin + simvastatin decreased hepatic and fecal lipids. In contrast to insulin + simvastatin treatment, all three doses of B. trimera effectively reduced AST and ALT levels.

CONCLUSION

B. trimera may be promising as a hepatoprotective agent against hepatic lesions that are caused by multiple risk factors.

Antifungal activity of phytotherapeutic preparation of Baccharis species from argentine Puna against clinically relevant fungi

ETHNOPHARMACOLOGICAL RELEVANCE

B. boliviensis and B. tola are used in traditional medicine in the Argentine Puna to treat skin and soft tissue infections and inflammatory processes in humans and animals.

AIM OF THE STUDY

To assess the potential of phytotherapeutic preparations of Baccharis species as antifungal agents against clinically relevant fungi and to determine the chemical composition of the extracts.

MATERIAL AND METHODS

Phytotherapeutic preparations of B. boliviensis and B. tola collected in Argentine Puna were evaluated as an antifungal agent against clinically relevant fungi (yeast, non-dermatophytes, and dermatophytes) isolated of patients from a local Hospital, and reference strains, using macrodilution and microdilution assays. The bioactivity was supported by UHPLC-OT-MS metabolome fingerprinting.

RESULTS

The results revealed that the plant preparations were active against most of evaluated fungal strains; B. boliviensis was more active than B. tola. Dermatophyte fungi strains were the most sensitive isolates. The phytotherapeutic preparation showed Minimal Inhibitory Concentration (MIC) values between 25 and 400 μg GAE/mL and Minimum Fungicidal Concentration (MFC) values between 50 and 400 μg GAE/mL. Regarding the phytochemical analysis, total phenolic and total flavonoid contents of hydroalcoholic preparation of B. boliviensis were greater than those of the B. tola extract. Both Baccharis species showed similar chromatographic patterns, fifty-two compounds were identified based on UHPLC-OT-MS including several terpenoids, flavonoids and phenolic acids that have been identified in this two endemic South American Baccharis species for the first time. Several identified compounds present antifungal properties, the presence of these compounds support the bioactivity of the Baccharis extracts.

CONCLUSIONS

In this work the traditional use of both Baccharis species as an antimicrobial against commercial products resistant fungal strains was validate, principally against dermatophytes fungi such as T. rubrum, T. mentagrophytes, M. canis, and M. gypseum. These results indicate that the hydroalcoholic preparations could be used for the treatment of fungal infectious.

Specificity of plant-plant communication for Baccharis salicifolia sexes but not genotypes

Plants are able to adjust their anti-herbivore defenses in response to the volatile organic compounds (VOCs) emitted by herbivore-damaged neighbors, and some of these changes increase resistance against subsequent herbivory. This phenomenon of plant-plant communication is thought to be widespread, but recent investigations have cautioned that it can be context dependent, including variation in the strength of communication based on the identity of plants and their associated herbivores. Here, we performed three greenhouse experiments using multiple male and female genotypes of the dioecious woody shrub Baccharis salicifolia and its specialist aphid Uroleucon macolai to test for specificity of plant-plant communication with respect to plant sex and genotype. Moreover, we evaluated plant sexual dimorphism and genotypic variation in VOC emissions (i.e., the "speaking" side of the interaction) and response of plants to VOC exposure (i.e., the "listening" side of the interaction) in order to identify the chemical mechanisms underlying such specificity. We did not find genotypic specificity of communication; emitter plants damaged by U. macolai significantly reduced subsequent U. macolai performance on receivers, but these effects were indistinguishable for communication within vs. among genotypes. In contrast, we found sex specificity of communication; male emitter plants reduced subsequent U. macolai performance on male and female receiver plants equally, while female emitter plants only did so for female receivers. We found sexual (but not genotypic) dimorphism in speaking but not listening; of the seven compounds induced by U. macolai feeding (speaking), pinocarvone was approximately fivefold greater in female than in male plants, while exposure of plants to pinocarvone emissions (listening) reduced U. macolai performance equally in both male and female plants. Together, our study demonstrates novel evidence for sexually dimorphic specificity of plant-plant communication and the chemical mechanism underlying this effect.

Inducing rapid seed germination of native cool season grasses with solid matrix priming and seed extrusion technology

There is a need to develop effective techniques for establishing native vegetation in dryland ecosystems. We developed a novel treatment that primes (hydrates) seeds in a matrix of absorbent materials and bio-stimulants and then forms the mixture into pods for planting. In the development process, we determined optimal conditions for priming seeds and then compared seedling emergence from non-treated seeds, non-primed-seed pods, and primed-seed pods. Emergence trials were conducted on soils collected from a hillslope and ridgetop location on the Kaibab Plateau, Arizona, USA. Poa fendleriana and Pseudoroegneria spicata were used as test species. Seeds were primed from -0.5 to -2.5 MPa for up to 12 d. Seeds primed under drier conditions (-1.5 to -2.5 MPa) tended to have quicker germination. Days to 50% emergence for primed-seed pods was between 66.2 to 82.4% faster (5.2 to 14.5 d fewer) than non-treated seeds. Seedling emergence from primed-seed pods for P. fendleriana was 3.8-fold higher than non-treated seeds on the ridgetop soil, but no difference was found on the other soil. Final density of P. spicata primed-seed pods were 2.9 to 3.8-fold higher than non-treated seeds. Overall, primed-seed pods show promise for enhancing germination and seedling emergence, which could aid in native plant establishment.

Physicochemical Characteristics of Brazilian Green Propolis Evaluated During a Six-Year Period

BACKGROUND

Propolis has been used as a natural health product mainly due to the presence of polyphenols, flavonoids, phenolic aldehydes, amino acids, vitamins and others bioactive constituents. To this natural substance are attributed different biological and pharmacological properties which are influenced by its chemical composition and organoleptic properties. The aim of this work was to evaluate the physicochemical properties and parameters of green propolis collected during a period of six years (2008-2013) in the state of Minas Gerais, located at the southeastern region of Brazil.

METHODS

The methodology were in accordance with Brazilian legislation on the identity and quality standards of propolis. The evaluated parameters of hydroalcoholic from green propolis were total flavonoids, antioxidant activity - DPPH method, oxidation index, wax content, humidity and insoluble impurities.

RESULTS

Propolis samples collected in different seasons during the years 2008 to 2013 presented mean values of total flavonoids (3.4 ± 0.11 mg/g), antioxidant activity DPPH (4.76 ± 0.16 μg/mL), oxidation index (3, 4 ± 0.33 seconds) and wax (15.14 ± 0.78% m/m), which are in accordance with Brazilian legislation.

CONCLUSION

Green propolis did not show abrupt seasonal changes during the six years of investigation, and may be considered as an adequate functional ingredient.

Antimicrobial and antibiofilm activity of Baccharis psiadioides essential oil against antibiotic-resistant Enterococcus faecalis strains

CONTEXT

Baccharis psiadioides (Less.) Joch. Müller (Asteraceae) is considered as a producer of bioactive essential oils and is used in south Brazilian folk medicine for its proprieties as stimulant, antipyretic, anti-inflammatory and as an antidote for snake bites.

OBJECTIVE

To verify the antimicrobial and antibiofilm activities of the essential oil of B. psiadioides (EOBP) against antibiotic-resistant Enterococcus faecalis.

MATERIALS AND METHODS

The initial evaluation of EOBP activity was conducted by the agar and microdilution methods against 13 antibiotic-resistant E. faecalis strains. The antibiofilm effect was determined by the application of EOBP in the earlier adherent cells or to the stabilized biofilm for 24 h and was evaluated by crystal violet, viability and scanning electron microscopy (SEM) assays. Chemical composition of EOBP was determined by gas chromatography (GC/FID - GC/MS).

RESULTS

The MIC values for EOBP were at least 1.25% and 4-16% for agar and microdilution assays, respectively. The EOBP reduced the microbial adherence and the viability of the cells, but did not cause the complete disruption of biofilms. SEM images indicate that EOBP influences the adherence of cells to a surface. The monoterpene β-pinene was the major constituent identified in EOBP.

CONCLUSION

This research shows the ability of EOBP to control resistant E. faecalis strains and to reduce the biofilm amount attached to abiotic surfaces, indicating its role as a promising new natural antimicrobial agent. Moreover, these results further contribute to the growing number of studies of plant natural products which suggest that these compounds can combat resistant microorganisms.

Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells

Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear. Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms. Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20-75 μg/mL), EEEP (1.25-3.75 μg/mL) and EECP (1.25-5 μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis. Results EEBGP mainly contains chlorogenic acid (8.98 ± 0.86 mg/g), kaempferide (11.18 ± 8.31 mg/g) and artepillin C (107.70 ± 10.86 mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC50 19.55 ± 1.28), ABTS (IC50 20.0 ± 0.31) and reducing power (2.70 ± 0.08 mmol TE/g) better than EEBGP's DPPH (IC50 43.85 ± 0.54), ABTS (IC50 38.2 ± 0.33) and reducing power (1.53 ± 0.05 mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway. Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.

Chemical and toxicological effects of medicinal Baccharis trimera extract from coal burning area

The entire process of power generation, extraction, processing and use of coal strongly impact water resources, soil, air quality and biota leads to changes in the fauna and flora. Pollutants generated by coal burning have been contaminating plants that grow in area impacted by airborne pollution with high metal contents. Baccharis trimera is popularly consumed as tea, and is widely developed in Candiota (Brazil), one of the most important coal burning regions of the Brazil. This study aims to investigate the phytochemical profile, in vivo genotoxic and mutagenic potential of extracts of B. trimera collected from an exposed region to pollutants generated by coal burning (Candiota City) and other unexposed region (Bagé City), using the Comet assay and micronucleus test in mice and the Salmonella/microsome short-term assay. The HPLC analyses indicated higher levels of flavonoids and phenolic acids for B. trimera aqueous extract from Bagé and absence of polycyclic aromatic hydrocarbons for both extracts. The presence of toxic elements such as cobalt, nickel and manganese was statistically superior in the extract from Candiota. For the Comet assay and micronucleus test, the mice were treated with Candiota and Bagé B. trimera aqueous extracts (500-2000 mg/kg). Significant genotoxicity was observed at higher doses treated with B. trimera aqueous extract from Candiota in liver and peripheral blood cells. Micronuclei were not observed but the results of the Salmonella/microsome short-term assay showed a significant increase in TA98 revertants for B. trimera aqueous extract from Candiota. The extract of B. trimera from Candiota bioacumulated higher levels of trace elements which were associated with the genotoxic effects detected in liver and peripheral blood cells.

Green Propolis: Thirteen Constituents of Polar Extract and Total Flavonoids Evaluated During Six Years through RP-HPLC

In order to verify the chemical qualities of polar extract of Green Propolis produced in the State of Minas Gerais, Brazil, was analyzed by means of RP-HPLC, the concentration of eleven flavonoids, Artepillin C and p-coumaric acid were analyzed by means of RP-HPLC. Samples were collected in the months of February, March, May, July, September, and October, during a period of six years (2008 to 2013) and the results compared with purchased standards. Artepillin C was the main constituent (80-90%) found in all samples. Lower concentrations of p-coumaric acid, chrysin and kaempferide were observed in March, and of ricin and galangin in September. Respectively, these months correspond to the end of Summer and Spring period in Brazil. The variation in concentration of the analyzed constituents always occurred in the same month, during the entire six years of evaluation period. All thirteen constituents of Green Propolis were detected throughout the study period, and the average concentration of each one was similar in relation to the respective monthly collection period of each year. Due to similarities among chemical constituents of Green Propolis with those present in B. dracuncufolia, this plant was identified as being the principal source of Green Propolis.

Inhibition of the human neutrophil oxidative metabolism by Baccharis dracunculifolia DC (Asteraceae) is influenced by seasonality and the ratio of caffeic acid to other phenolic compounds

ETHNOPHARMACOLOGICAL RELEVANCE

The great potential of phytotherapic drugs for treating and preventing inflammatory diseases mediated by increased neutrophil reactive oxygen species (ROS) generation has guided the search for new natural products with antioxidant and immunomodulatory properties. Baccharis dracunculifolia D.C. (Asteraceae), the main botanical source of Brazilian green propolis, is a native plant from Brazil widely used in folk medicine as anti-inflammatory. This study aims: (a) to determine the influence of seasonality on the chemical profile and biological activity of Baccharis dracunculifolia (Asteraceae) leaf extracts (BdE); (b) to analyze the correlation between the major compounds and the ability of BdE to modulate the superoxide anion and total ROS generation by human neutrophils.

MATERIALS AND METHODS

The extracts were obtained from leaf samples collected monthly during one year. The superoxide anion and total ROS generation were assessed by the lucigenin (CL-luc)- and luminol (CL-lum)-enhanced chemiluminescence assays.

RESULTS

Seasonality influenced more the quantitative than the qualitative chemical profile of B. dracunculifolia, and affected its biological activity. The major compounds identified were caffeic acid, p-coumaric acid, aromadendrin-4'-methyl ether (AME), isosakuranetin and artepillin C. The IC₅₀ values obtained for CL-lum and CL-luc inhibition by BdE ranged from 8.1-15.8 and 5.8-13.3µgmL(-1), respectively, and correlated positively with caffeic acid concentration. CL-luc inhibition correlated negatively with the concentration of artepillin C, AME, isosakuranetin and total flavonoids. The BdE sample from May/07 inhibited CL-lum and CL-luc the most strongly (IC₅₀=8.1 ± 1.6 and 5.8 ± 1.0 µg mL(-1), respectively), and contained the highest ratio of caffeic acid to the other isolated compounds; so, this ratio could be employed as chemical marker for this biological activity of B. dracunculifolia.

CONCLUSION

The ability of B. dracunculifolia to inhibit the neutrophil ROS generation depends more on the type and ratio of phenolic compounds and flavonoids than on their high absolute concentrations. Together, our results help select the most appropriate plant material for the production of phytotherapic drugs to be used in the treatment of inflammatory diseases mediated by increased neutrophil activation.

Fortified extract of red berry, Ginkgo biloba, and white willow bark in experimental early diabetic retinopathy

Diabetic retinopathy is a complex condition where inflammation and oxidative stress represent crucial pathways in the pathogenesis of the disease. Aim of the study was to investigate the effects of a fortified extract of red berries, Ginkgo biloba and white willow bark containing carnosine and α-lipoic acid in early retinal and plasma changes of streptozotocin-induced diabetic rats. Diabetes was induced by a single streptozotocin injection in Sprague Dawley rats. Diabetics and nondiabetic (control) rats were treated daily with the fortified extract for the ten days. Retina samples were collected and analyzed for their TNF-α and VEGF content. Moreover, plasma oxidative stress was evaluated by thiobarbituric acid reacting substances (TBARS). Increased TNF-α and VEGF levels were observed in the retina of diabetic rats. Treatment with the fortified extract significantly lowered retinal cytokine levels and suppressed diabetes-related lipid peroxidation. These data demonstrate that the fortified extract attenuates the degree of retinal inflammation and plasma lipid peroxidation preserving the retina in early diabetic rats.

Effects of California chaparral plants on in vitro ruminal fermentation of forage and concentrate diet

BACKGROUND

The combustible nature of chaparral plants has been attributed to the presence of secondary compounds such as phenolic acids, flavonoids and essential oils, among others. However, the implication of the antimicrobial properties of secondary compounds of chaparral in modulating rumen microbial metabolism has not been determined. The effects of 11 chaparral plants on rumen microbial fermentation were assessed in an in vitro batch culture fermentation fed a barley silage:barley grain-based low concentrate (LC) and high concentrate (HC) diets.

RESULTS

With LC, gas production [g dry matter (DM) incubated] and DM disappearance (DMD) were unaffected by Adenostoma fasciculatum, Ceanothus cuneatus, Baccharis pilularis or Eriodictyon californicum, but all plants except C. cuneatus decreased (P < 0.05) CH(4) production. With HC diet, all species except A. fasciculatum decreased (P < 0.01) total gas produced. Total volatile fatty acids (VFA) produced, molar proportions of acetate, propionate and butyrate, and the acetate:propionate (A:P) ratio were unaffected by chaparral addition to both HC and LC diets. Increased concentrations of A. fasciculatum and E. californicum decreased (linear; P < 0.05) fermentability and productions of CH(4) and NH(3) -N.

CONCLUSION

Among all chaparral species investigated A. fasciculatum and E. californicum added as 10% of LC diet showed some potential to exert beneficial effects on rumen microbial fermentation.

The tri-trophic interactions hypothesis: interactive effects of host plant quality, diet breadth and natural enemies on herbivores

Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI) hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists) should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality) host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia) quality and predators between a specialist (Uroleucon macolai) and a generalist (Aphis gossypii) aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores.

Anti-inflammatory effect of crude extract and isolated compounds from Baccharis illinita DC in acute skin inflammation

ETHNOPHARMACOLOGYCAL RELEVANCE: The tea from the leaves of Baccharis illinita DC (Asteraceae family) is commonly used by the population as anti-inflammatory (including topically), protective gastric and anti-infectious. However, no studies have been done with this species to confirm its topical anti-inflammatory action.

AIM

This study evaluated he topical effects of crude extract of leaves (CE) and its active constituents in 12-O-tetradecanoylphorbol acetate (TPA)-induced ear oedema.

METHODOLOGY

CE and compounds effects were tested in commonly used models of TPA-, arachidonic acid (AA)- and capsaicin-ear oedema. Polymorphonuclear (PMN) cell migration was evaluated by mieloperoxidase and analyzed histologically.

RESULTS

CE (0.1-1 mg/ear) caused a dose-related inhibition of TPA-induced ear oedema and PMN influx similarly to that produced by topical application of the steroidal anti-inflammatory drug dexamethasone. The active constituents of the AcOEt fraction kaurenoic acid, alpha-spinasterol, oleanolic acid and baurenol also inhibited TPA-induced ear edema. Histological analysis of the ear of CE-treated animals confirmed the reduction of edema and of PMN infiltration. Both CE and the nosteroidal anti-inflammatory drug indomethacin inhibited the AA-induced ear oedema, but did not change capsaicin-induced oedema.

CONCLUSION

These results indicate that the CE and the active constituents have a topical anti-inflammatory effect and the possible mechanisms for the pharmacological effects are discussed.

Anti-inflammatory and antinociceptive effects of Baccharis dracunculifolia DC (Asteraceae) in different experimental models

AIM OF THE STUDY

The aerial parts of Baccharis dracunculifolia D.C., popularly known as "alecrim do campo", are used in folk medicine as anti-inflammatory. The aim of the present study was to evaluate the anti-inflammatory and antinociceptive activities of the crude hydroalcoholic extract obtained from leaves of Baccharis dracunculifolia (BdE), which have not been reported.

MATERIALS AND METHODS

BdE was analyzed by HPLC and in vivo evaluated (doses ranging from 50 to 400mg/kg, p.o.) by using the acetic acid-induced abdominal constrictions, paw oedema induced by carrageenan or histamine, overt nociception models using capsaicin, glutamate or phorbol myristate acetate (PMA), formalin-induced nociception and mechanical hypernociception induced by carrageenan or complete Freund adjuvant (CFA). As positive controls it was used paracetamol in both acetic acid and formalin tests; dipyrone in capsaicin, glutamate and PMA-induced nociception; indomethacin in CFA and carrageenan-induced hypernociception models. In addition, the in vitro effects of BdE on COX-2 activity and on the activation of NF-kappaB were also evaluated.

RESULTS

BdE (50-400mg/kg, p.o.) significantly diminished the abdominal constrictions induced by acetic acid, glutamate and CFA. Furthermore, BdE also inhibited the nociceptive responses in both phases of formalin-induced nociception. BdE, administered orally, also produced a long-lasting anti-hypernociceptive effect in the acute model of inflammatory pain induced by carrageenan. It was also observed the inhibition of COX-2 activity by BdE.

CONCLUSION

In summary, the data reported in this work confirmed the traditional anti-inflammatory indications of Baccharis dracunculifolia leaves and provided biological evidences that Baccharis dracunculifolia, like Brazilian green propolis, possess antinociceptive and anti-inflammatory activities.

Mutagenic and genotoxic effects of Baccharis dracunculifolia (D.C.)

Baccharis dracunculifolia (D.C.) (Asteraceae), a native plant to Brazil known as "vassourinha" or "alecrim-do-campo", is the most important botanical source of a Brazilian propolis called green propolis. The leaf extracts of this plant have been used to treat liver and digestive disorders. It has been recognized that green propolis can induce mutagenic effects at high doses, but no study reporting possible mutagenic effects by Baccharis dracunculifolia extracts in the maximum tolerated dose has been conducted. The aim of the present study was to investigate the genotoxic and mutagenic effects of this plant in vivo. Adult CF-1 mice were treated with 0.5g/kg, 1.0g/kg or 2.0g/kg of an aqueous extract of Baccharis dracunculifolia by gavage for 3 consecutive days. Blood and liver samples were collected to detect DNA damage using the comet assay, while bone marrow samples were used to assess chromosome mutations by the micronucleus test. The extract increased the DNA damage in blood and liver tissues and the frequency of micronucleus in bone marrow. These findings suggest genotoxic and mutagenic effects of Baccharis dracunculifolia comparable to green propolis in mice.

Inhibition of doxorubicin-induced mutagenicity by Baccharis dracunculifolia

Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, have been used as an antipyretic, stomachic and health tonic in Brazil. The objective of the present study was to investigate the potential mutagenic effect of B. dracunculifolia ethyl acetate extract (Bd-EAE) and its influence on the mutagenicity induced by the chemotherapeutic agent doxorubicin (DXR) using the rat bone marrow and peripheral blood micronucleus test. Wistar rats were divided into 10 treatment groups. Five groups received DXR (90 mg/kg body weight, b.w., intraperitoneally) to induce mutagenicity and three of these groups received a single oral dose of Bd-EAE at a concentration of 6, 12 or 24 mg/kg b.w. prior to DXR administration. A vehicle-treated control group and Bd-EAE control groups were also included. The results showed that Bd-EAE itself was not mutagenic, in the rat micronucleus assay. In animals treated with Bd-EAE and DXR, the number of MNPCEs was significantly decreased compared to animals receiving DXR alone. HPLC analysis of the extract obtained permitted the identification of the following phenolic compounds: caffeic acid, p-coumaric acid, aromadendrin-4'O-methyl ether, 3-prenyl-p-coumaric acid (drupanin), 3,5-diprenyl-p-coumaric acid (artepillin C) and baccharin. The putative antioxidant activity or the interference of one or more of the active compounds of Bd-EAE with mutagenic metabolic pathways may explain its effect on DXR mutagenicity.

Anti-inflammatory activity of four Bolivian Baccharis species (Compositae)

Hexanic, dichloromethanic, ethanolic and aqueous extracts from Baccharis obtusifolia HBK, Baccharis latifolia (R. et P.) Pers., Baccharis pentlandii D.C. and Baccharis subulata Wedd., plants used in the traditional medicine of South America have been studied for their in vitro anti-inflammatory activity in cellular systems. Calcium ionophore A23187-stimulated mouse peritoneal macrophages were validated as a source of cyclooxygenase-1 (COX-1) (prostaglandin E2, PGE2) and 5-lipoxygenase (5-LOX) (leukotriene C4, LTC4), and mouse peritoneal macrophages stimulated with Escherichia coli lipopolysaccharide (LPS) were used for testing cyclooxygenase-2 (COX-2) (PGE2), nitric oxide (NO) and tumour necrosis factor-alpha (TNF-alpha) activity. Most of the extracts tested were active in all assays.

Effect of the extracts and fractions of Baccharis trimera and Syzygium cumini on glycaemia of diabetic and non-diabetic mice

In the present study, we investigated the effects of extracts and fractions of Baccharis trimera and Syzygium cumini on glycaemia of diabetic and non-diabetic mice. Crude ethanolic extracts and aqueous and butanolic fractions of the aerial parts of Baccharis trimera and leaves of Syzygium cumini were evaluated. None of the extracts or fractions (200 or 2000 mg/kg, per os) induced any effect after acute administration. Seven-day treatment with crude ethanolic and aqueous and butanolic fractions (200-2000 mg/kg, twice daily, per os) of Syzygium cumini reduced glycaemia of non-diabetic mice. However, this effect was associated with a reduction of food intake and body weight, indicating that this may not be a genuine hypoglycaemic effect. In diabetic mice, only the aqueous fraction of Baccharis trimera (2000 mg/kg, twice daily, per os) reduced the glycaemia after a 7-day treatment. This effect was not associated with a body weight reduction. The results suggest that Baccharis trimera presents a potential antidiabetic activity and indicate that food intake and body weight must be determined when evaluating metabolic parameters after prolonged administration of plant extracts.

In-vitro trypanocidal activity evaluation of crude extract and isolated compounds from Baccharis dracunculifolia D.C. (Asteraceae)

We have performed a trypanocidal bioactivity-guided study of Baccharis dracunculifolia (Asteraceae), the main botanical origin of Brazilian green propolis. The leaf rinse extract of B. dracunculifolia, at a concentration of 3.0 mg mL(-1), displayed 100% lysis of trypomastigote forms of the Y strain of Trypanosoma cruzi (2 x 10(6) parasites mL(-1)). The chromatographic fractionation of the leaf rinse, using several techniques, afforded the isolation of the compounds isosakuranetin (1), aromadendrin-4'-methylether (2), baccharis oxide (3), ferulic acid (4), dihydrocinnamic acid (5), 3-prenyl-4-(dihydrocinnamoyloxy)-cinnamic acid (6), and friedelanol (7). The chemical structures of all compounds were established by UV-vis, (1)H and (13)CNMR data analysis in comparison with the literature. Compounds 1 and 3 were the most active in the trypanocidal assay, showing IC50 values (inhibitory concentration required for 50% inhibition) of 247.6 and 249.8 microM, respectively. Compounds 2, 4, and 6 displayed moderate activity, whilst compounds 5 and 7 were inactive.

Free radical scavengers and antioxidants from Baccharis grisebachii

The exudate and seriated extracts from the aerial parts of Baccharis grisebachii (Asteraceae) which is recommended as a digestive and to relieve gastric ulcers in Argentina, showed activity as free radical scavengers and inhibited lipoperoxidation in erythrocytes. Assay-guided isolation led to seven p-coumaric acid derivatives and six flavonoids as the main active constituents of the crude drug. The activity towards the superoxide anion was mainly due to the flavonoid constituents. 5,7,4'-Trihydroxy-6-methoxyflavone and quercetin presented high activity (64 and 79%) even at 12.5 microg/ml. The xanthine oxidase inhibitory effect of the extracts can be related with the p-coumaric acid derivatives drupanin, 4-acetyl-3,5-diprenylcinnamic acid and trans-ferulic acid O-hexan-3-onyl-ether which showed IC(50) values in the range 28-40 microg/ml. Both p-coumaric acid derivatives and flavonoids inhibited lipoperoxidation in erythrocytes. The highest activity was found for the p-coumaric acid derivatives 4-acetyl-3-prenyl-ethoxycinnamate, 3-prenyl-4-(4'-hydroxydihydrocinnamoyloxy)-cinnamate and trans-ferulic acid O-hexan-3-onyl-ether (69-82%) and the flavonoids 5,7,4'-trihydroxy-6-methoxyflavone, quercetin, 5,7,4'-trihydroxy-6,3'-dimethoxyflavone and 5,7,4'-trihydroxy-6,8-dimethoxyflavone (64-84%) at 100 microg/ml. The most active free radical scavengers measured by the DPPH decoloration assay were the p-coumaric acid derivatives drupanin and trans-ferulic acid O-hexan-3-onyl-ether (27-35% at 10 microg/ml) and the flavonoid quercetin (97 and 23% at 10 and 1 microg/ml, respectively). The results support the use of Baccharis grisebachii in Argentinian traditional medicine.

Comparative Evaluation of in-Vitro Effects of Brazilian Green Propolis and Baccharis dracunculifolia Extracts on Cariogenic Factors of Streptococcus mutans

Streptococcus mutans triggers dental caries establishment by two major factors: synthesis of organic acids, which demineralize dental enamel, and synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Propolis is a natural product that may prevent dental caries. Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, is the most important botanical origin for the production of green propolis (Brazilian propolis) by honeybees. However, whether B. dracunculifolia (Bd) has an anticariogenic effect, like green propolis, remains unknown. Herein, we have made a comparative evaluation of the effects of extracts from green propolis and Bd on the glucan synthesis and acidogenic potential of S. mutans. The inhibitory effects of the extracts on bacterial acid production were evaluated through the potentiometric measurement of pH from bacterial suspensions treated with serial concentrations of both extracts. Besides presenting close inhibitory values at the same concentration range, Bd leaf rinse and green propolis extracts had similar IC(50) values (0.41 and 0.34 mg/ml, respectively). Both extracts produced a bacteriostatic effect on S. mutans cultures at a concentration of 0.40 mg/ml. Estimated inhibitory values of green propolis and Bd leaf rinse extracts on the synthesis of insoluble glucans (IC(50)=12.9 and 25.0 microg/ml, respectively) and soluble glucans (IC(50)=50.4 and 49.1 microg/ml, respectively) were not significantly different from each other at p<0.05. The results demonstrate that Bd leaf rinse and green propolis extracts have similar inhibitory effects on the S. mutans cariogenic factors evaluated herein, and allowed us to suggest that Bd leaves may be a potential source for pharmaceutical products employed for this purpose.

Constituents of the Argentinian medicinal plant Baccharis grisebachii and their antimicrobial activity

The resinous exudate of Baccharis grisebachii which is used to treat ulcers, burns, and skin sores in Argentina showed activity towards dermatophytes and bacteria. Two diterpenes, eight p-coumaric acid derivatives, and two flavones were isolated from the exudate and the structures elucidated by spectroscopic methods. 3-Prenyl-p-coumaric acid and 3,5-diprenyl-p-coumaric acid were active towards Epidermophyton floccosum and Trichophyton rubrum with MICs of 50 and 100-125 microg/ml, respectively. The diterpene labda-7,13E-dien-2beta,15-diol was active towards Epidermophyton floccosum and Trichophyton rubrum with MICs of 12.5 microg/ml while the MIC against Microsporum canis and Trichophyton mentagrophytes was 25 microg/ml. The diterpene was also active towards Microsporum gypseum with a MIC of 50 microg/ml, and showed inhibition in both Staphylococcus aureus (methicilline resistant and sensible strains) with MICs of 125 microg/ml. The results support the use of Baccharis grisebachii in Argentinian traditional medicine.

Argentinian plant extracts with relaxant effect on the smooth muscle of the corpus cavernosum of guinea pig

Extracts of different polarity from Baccharis trimera, Haplopappus rigidus Huperzia saururus, Maytenus ilicifolia, Satureja parvifolia and Senecio eriophyton were tested for their relaxant activity on smooth muscle using L-phenylephrine precontracted strips of corpus cavernosum obtained from Guinea pigs. Highly significant and dose dependent results were obtained with the dichloromethane extracts of H. saururus (87% of relaxation at the dose of 10 mg/ml), S. parvifolia (95% of relaxation at 2.5 mg/ml) and S. eriophyton (94% of relaxation at 5 mg/ml). Similar effects were observed with the methanol extracts of H. saururus (88% of relaxation at 10 mg/ml) and S. parvifolia (84% of relaxation at 10 mg/ml). These results were comparable to those obtained with the dichloromethane and methanol extracts of the well known Mexican species Turnera diffusa. Moreover, the aqueous extract of H. rigidus and the aqueous and methanol extracts of S. eriophyton were highly effective in a dose dependent manner (more than 90% of relaxation at the dose of 10 mg/ml). Significant results, but with a lower overall relaxant activity (about 70% of relaxation at 10 mg/ml), could also be obtained with the aqueous extract of S. parvifolia and with the dichlormethane and methanol extracts of B. trimera and M. ilicifolia. The positive controls with Sildenafil citrate at doses ranging from 0.35 to 35 microg/ml yielded moderate effects (up to 46% of relaxation at 35 microg/ml). The effects observed in the present study seem to validate the folk medicinal use of the tested plants and open new ways in the search for natural products with vasodilatory effects.

A new ent-clerodane diterpene from the aerial parts of Baccharis gaudichaudiana

A new ent-clerodane diterpene, named bacchariol (1) was isolated from the aerial parts of Baccharis gaudichaudiana DC. (Compositae), together with known ent-clerodane diterpenes (2, 3), eight known flavonoids (4-11) and 3, 5-dicaffeoylquinic acid (12). Their structures were determined by spectroscopic analyses. Flavonoids (7, 8, 11) and 12 showed moderate scavenging activities toward 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals.

Gastroprotective effects of a crude extract of Baccharis illinita DC in rats

Baccharis illinita DC (Compositae) is used in folk medicine to treat gastric disorders. The crude hydroalcoholic extract of leaves and stems tested on mice at doses from 1.0 to 6.0 g/kg, PO, did not produce signs of toxicity. Only the aqueous extract of leaves (0.1 g/kg, PO) increased intestinal motility in mice. The crude hydroalcoholic extract of stems and leaves (HESL) protected rats against lesions induced by ethanol or restraint-in-cold. The crude aqueous extract of roots protected against ulcers induced by ethanol, indomethacin or restraint-in-cold, and the crude aqueous extract of flowers only protected against lesions induced by ethanol. When injected into the duodenal lumen, the aqueous root extract inhibited basal acid secretion in pylorus-ligated rats. The results obtained in the present pharmacological assays indicate that this plant has a protective action against gastric lesions of the mucosa involving the maintenance of protective factors such as mucus, bicarbonate and blood flow, besides the reduction of gastric acid secretion.

Screening of South American plants against human immunodeficiency virus: preliminary fractionation of aqueous extract from Baccharis trinervis

Ethanolic and aqueous extracts of 14 South American medicinal plants were tested for inhibitory activity on human immunodeficiency virus (HIV). Both extracts were relatively non-toxic to human lymphocytic MT-2 cells, but only the aqueous extract of Baccharis trinervis exhibited potent anti-HIV activity in an in vitro MTT assay. To delineate the extract-sensitive phase, some studies of the antiviral properties of the active extract are described in this paper. Based on the results presented here, a separation scheme was devised, which permitted the preliminary fractionation of the extract, with the aim of finding an inhibitor of this virus.