Achyrocline satureioides review: From the pharmacochemical diversity to the technological development of products.

Achyrocline satureioides (Lam.) DC (Asteraceae) is a native species of the southeastern subtropical and temperate region of South America, popularly known as "marcela" or "macela". This species is recognized, in traditional medicine, by diverse biological activities such as digestive, antispasmodic, anti-inflammatory, antiviral, sedative, hepatoprotective, among others. Some of these activities have been related to the presence of phenolic compounds, including flavonoids, phenolic acids, terpenoids in the essential oils, coumarins and phloroglucinol derivatives reported to the species. The approaches on the technological development of phytopharmaceutical products of this species provided relevant advances in the optimization of the extraction and product obtention, especially spray-dried powders, hydrogels, ointments, granules, films, nanoemulsions and nanocapsules. The most relevant biological activities described for the extracts or derivative products from A. satureioides were antioxidant, neuroprotective, antidiabetic, antiobesity, antimicrobial, anticancer effects, and obstructive sleep apnea syndrome. The scientific and technological findings reported for the species, in conjunction with its traditional use and cultivation, reveal the high potential of the species for diverse industrial applications.

Hexanic extract of Achyrocline satureioides: antimicrobial activity and in vitro inhibitory effect on mechanisms related to the pathogenicity of Paenibacillus larvae.

INTRODUCTION: Paenibacillus larvae is a spore-forming bacillus, the most important bacterial pathogen of honeybee larvae and the causative agent of American foulbrood (AFB). Control measures are limited and represent a challenge for both beekeepers and researchers. For this reason, many studies focus on the search for alternative treatments based on natural products. AIM: The objective of this study was to determine the antimicrobial activity of the hexanic extract (HE) of Achyrocline satureioides on P. larvae and the inhibitory activity on some mechanisms related to pathogenicity. MATERIAL AND METHODS: The Minimum Inhibitory Concentration (MIC) of the HE was determined by the broth microdilution technique and the Minimum Bactericidal Concentration (MBC) by the microdrop technique. Swimming and swarming motility was evaluated in plates with 0.3 and 0.5% agar, respectively. Biofilm formation was evaluated and quantified by the Congo red and crystal violet method. The protease activity was evaluated by the qualitative technique on skim milk agar plates. RESULTS: It was determined that the MIC of the HE on four strains of P. larvae ranged between 0.3 and 9.37 µg/ml and the MBC between 1.17 and 150 µg/ml. On the other hand, sub-inhibitory concentrations of the HE were able to decrease swimming motility, biofilm formation and the proteases production of P. larvae.

Endophytic Fungus of Achyrocline satureioides: Molecular Identification, Chemical Characterization, and Cytotoxic Evaluation of its Metabolites in Human Melanoma cell line.

Endophytic fungi are important sources of anticancer compounds. An endophytic fungus was isolated from the medicinal plant Achyrocline satureioides, and molecularly identified as Biscogniauxia sp. (family Xylariaceae) based on partial nucleotide sequences of the internal transcribed spacer genomic region (GenBank Accession No. ON257911). The chemical characterization and cytotoxic properties of secondary metabolites produced by Biscogniauxia sp. were evaluated in a human melanoma cell line (A375). The fungus was grown in potato-dextrose liquid medium for 25 days, and the extracted compounds were subjected to solid-phase fractionation to obtain the purified FDCM fraction, for which the metabolites were elucidated via ultra-performance chromatography coupled to a mass spectrometer. In the present study, 17 secondary metabolites of Biscogniauxia sp., including nine polyketide derivatives, five terpenoids, and three isocoumarins, were putatively identified. This is the first study to report of the ability of Biscogniauxia sp. in the production of isocoumarin orthosporin; the terpenoids nigriterpene A and 10-xylariterpenoid; the polyketide derivatives daldinin C, 7'dechloro-5'-hydroxygriseofulvin, daldinone D, Sch-642305, curtachalasin A, cytochalasin E, epoxycytochalasins Z8, Z8 isomer, and Z17. Furthermore, this study has reported the biosynthesis of Sch-642305 by a Xylariaceae fungus for the first time. FDCM significantly reduced the viability and proliferation of human melanoma cells at half-maximal inhibitory concentrations ​​of 10.34 and 6.89 µg/mL, respectively, and induced late apoptosis/necrosis and cell cycle arrest in G2/M phase after 72 h of treatment. Given its ability to produce unique metabolites with promising cytotoxic effects, Biscogniauxia sp. of A. satureioides may be a reservoir of compounds with important therapeutic applications.

In Vitro Evaluation of Anti-Rotaviral Activity and Intestinal Toxicity of a Phytotherapeutic Prototype of Achyrocline bogotensis (Kunth) DC.

Viruses represent the primary etiologic agents (70-80%) of acute diarrheal disease (ADD), and rotavirus (RV) is the most relevant one. Currently, four rotavirus vaccines are available. However, these vaccines do not protect against emerging viral strains or are not available in low-income countries. To date, there are no approved drugs available against rotavirus infection. In this study, we evaluated the in vitro anti-rotaviral activity and intestinal toxicity of a phytotherapeutic prototype obtained from Achyrocline bogotensis (Kunth) DC. (PPAb); medicinal plant that contains compounds that inhibit the rotavirus replication cycle. Virucidal and viral yield reduction effects exerted by the PPAb were evaluated by immunocytochemistry and flow cytometry. Furthermore, the toxic impact of the PPAb was evaluated in polarized human intestinal epithelial C2BBe1 cells in terms of cytotoxicity, loss of cytoplasmic membrane asymmetry, and DNA fragmentation by MTT and fluorometry. PPAb concentrations under 0.49 mg/mL exerted significant virucidal and viral yield reduction activities, and concentrations under 16 mg/mL neither reduced cell viability, produced DNA fragmentation, nor compromised the C2BBe1cell membrane stability after 24-h incubation. Based on these results, the evaluated phytotherapeutic prototype of Achyrocline bogotensis might be considered as a promising alternative to treat ADD caused by rotavirus.

Fractionation of hexane extracts from Achyrocline satureioides and their biological activities against Paenibacillus larvae.

Previous studies carried out in our laboratory described the antimicrobial activity of the whole hexanic extract (HE) of Achyrocline satureioides (Lam.) DC against Paenibacillus larvae, the causal agent of American Foulbrood (AFB) a disease of the honey bee larvae. In this study, the HE was partitioned into five main fractions by chromatographic techniques leading to the isolation of four known compounds: two prenylated phloroglucinol α-pyrones (1 and 3), 5,7-dihydroxy-3,8-dimethoxyflavone (gnaphaliin A) (2), and 23-methyl-6-O-demethylauricepyrone (4). Isolated compounds were further analyzed towards structural elucidation using 1H RMN and 13C RMN spectroscopic techniques. For the first time, the antimicrobial activity of the isolated compounds was evaluated against P. larvae strains by broth microdilution method and compared with that of the whole HE. Compounds 1-4 displayed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranging between 0.07 and 62.5 µg/mL and 0.26 and 12.5 µg/mL, respectively. The lowest MIC and MBC values were obtained with compounds 3 and 4, respectively. The antimicrobial activity of each single compound and the combination of them showed that the presence of all compounds is needed for the antimicrobial efficacy of whole HE.

Antimycobacterial activity of Achyrocline flaccida (Asteraceae) aqueous extract from Southern Brazil.

Achyrocline flaccida aqueous extract was obtained by macerating wildflowers. The phytochemical profile present in the A. flaccida aqueous extract was elucidated by HPLC-ESI-MS/MS. Toxicity was evaluated in vitro by comet assay in peripheral blood mononuclear cells (PBMCs) and in vivo using Caenorhabditis elegans as a model. The antioxidant activity was also evaluated, and antimycobacterial activity was assessed by the broth microdilution method. The compounds present in the aqueous extract mainly belonged to the flavonoid class (89%). The concentrations that showed protective effects in C. elegans against oxidative stress and antimycobacterial activity had no toxic effects. The antimycobacterial activity test demonstrated that the concentration of 1,560 µg mL-1 inhibited the growth and eradication of the mycobacterial tested strains. Based on our findings, the A. flaccida aqueous extract presents a viable potential in developing new phytotherapeutic drugs against mycobacteria of clinical relevance.

3-O-Methylquercetin from Achyrocline satureioides-cytotoxic activity against A375-derived human melanoma cell lines and its incorporation into cyclodextrins-hydrogels for topical administration.

3-O-Methylquercetin (3OMQ), a natural 3-O-methylflavonoid, was isolated from Achyrocline satureioides and purified using the high-performance counter current chromatography (HPCCC) on a semi-preparative scale. High-purity 3OMQ (98%) was obtained with excellent recovery (81.8% (w/w)) and good yield (190 mg/100 g of plant). Isolated 3OMQ was evaluated against the A375 human amelanotic melanoma cancer cell line and A375-derived with different degrees of aggressiveness (A375-A7, A375-G10, and A375-PCDNA3). The results showed that 3OMQ reduced the cell viability of all strains, demonstrating time- and dose-dependent responses. 3OMQ was used to obtain hydrogels for the topical treatment of melanoma. Thus, 3OMQ was incorporated into hypromellose hydrogels with/without different cyclodextrins (CDs). The 3OMQ formulations showed permeation/retention in all skin layers, namely stratum corneum, epidermis, and dermis. A significant amount of 3OMQ was found in the replication site of the melanoma cells (epidermis and dermis). Altogether, these results demonstrate that 3OMQ can be isolated from Achyrocline satureioides by HPCCC on a semi-preparative scale and exhibit cytotoxic activity against melanoma cells. Its incorporation into an HPMC hydrogel containing HP-ß-CD yielded a formulation with excellent technological and biopharmaceutical characteristics for evaluating the topical management of melanoma.

Box-Behnken Design for Extraction Optimization Followed by High Performance Countercurrent Chromatography: Production of a Flavonoid-enriched Fraction from Achyrocline Satureioides.

The biological properties of Achyrocline satureioides have been mostly ascribed to its major flavonoids quercetin (QCT), luteolin (LUT), and 3-O-methylquercetin (3OMQ). The present study aimed to optimize the extraction by dynamic maceration of the major phenolic compounds in order to obtain in a subsequent step a flavonoid-enriched fraction (FEF) using high performance countercurrent chromatography (HPCCC). A 3-level Box-Behnken design (BBD) was applied to maximize the extraction of the substances, using the plant : solvent ratio (X1 ), extraction time (X2 ), and ethanol concentration (X3 ) as factors. One-step HPCCC semipreparative separation with a solvent system composed of hexane : ethyl acetate : methanol : water (0.9 : 0.9 : 0.8 : 1.0, v/v) was employed to obtain the FEF. The second-order polynomial model was able to fit the experimental data adequately. The linear and quadratic terms of X3 were the most significant factors that affected all the responses. The positive linear term of X3 indicated a substantial increase in extraction yield, while the negative quadratic term showed a nonlinear tendency. Linear terms of X1 suggested a tendency to solvent saturation, except for QCT. The terms of X2 did not affect the responses substantially. The HPCCC method was found to be efficient and rapid for separating the FEF with 71% (w/w) flavonoid content. Overall, the developed extraction procedure coupled with HPCCC proved to be efficient for obtaining an enriched fraction with a very high content of flavonoids from A. satureioides.

Purification, structural elucidation, antioxidant capacity and neuroprotective potential of the main polyphenolic compounds contained in Achyrocline satureioides (Lam) D.C. (Compositae).

Achyrocline satureioides (Lam) D.C (Compositae) is a native medicinal plant of South America traditionally utilized for its anti-inflammatory, sedative and anti-atherosclerotic properties among others. Neuroprotective effects have been reported in vivo and could be associated to its elevated content of flavonoid aglycones. In the present study we performed the isolation and structure elucidation of the major individual flavonoids of A. satureioides along with the in vitro characterization of their individual antioxidant and neuroprotective properties in order to see their putative relevance for treating neurodegeneration. Exact mass, HPLC-MS/MS and 1H NMR identified dicaffeoyl quinic acid isomers, quercetin, luteolin, isoquercitrin, and 3-O-methylquercetin as the mayor polyphenols. Flavonoids intrinsic redox properties were evaluated in the presence of the endogenous antioxidants GSH and Ascorbate. Density Functional Theory (DFT) molecular modeling and electron density studies showed a theoretical basis for their different redox properties. Finally, in vitro neuroprotective effect of each isolated flavonoid was evaluated against hydrogen peroxide-induced toxicity in a primary neuronal culture paradigm. Our results showed that quercetin was more efficacious than luteolin and isoquercitrin, while 3-O-methylquercetin was unable to afford neuroprotection significantly. This was in accordance with the susceptibility of each flavonoid to be oxidized and to react with GSH. Overall our results shed light on chemical and molecular mechanisms underlying bioactive actions of A. satureioides main flavonoids that could contribute to its neuroprotective effects and support the positive association between the consumption of A. satureioides as a natural dietary source of polyphenols, and beneficial health effect.

Effects of exposure to ethanolic extract from Achyrocline satureioides (Lam.) D.C. flowers on reproductive and developmental parameters in Wistar rats.

Achyrocline satureioides (LAM) D.C. is a species plant used in folk medicine with several medicinal properties; however, few studies have focused on its potential adverse effects. The aim of this study was to examine the effects of ethanolic extract of A. satureioides flowers administered during pre-mating, mating, pregnancy and postpartum period on reproductive and developmental parameters in rats. Male and female rats received by gavage 0, 250, 500 or 750 mg/kg of extract. The animals were treated from pre-mating until 13 days post-partum. Phytochemical analysis revealed the presence of important flavonoids (quercetin, luteolin, caffeic acid, rutin, and ferulic acid). In females, biochemical, hematological or gestational parameters were not markedly altered by the extract. However, an increase in calcium and thyroid stimulating hormone (TSH) levels was found in treated-dams. Although TSH and T4 levels were not significantly altered in pups, there was a rise in body weight of pups whose mothers were treated with the extract. All males treated were able to successfully copulate with treated-females. However, rats exposed to 500 and 750 mg/kg of extract exhibited a significant decrease in daily testicular sperm production and delay in sperm transit time in the epididymis. The ethanolic extract of A. satureioides flowers produced adverse effects in the male reproductive system as evidenced by diminished sperm production and transport. In addition, the extract elevated TSH levels of exposed mothers which may consequently affect the development of pups but this requires further evaluation.

Semi-preparative isolation and purification of phenolic compounds from Achyrocline satureioides (Lam) D.C. by high-performance counter-current chromatography.

INTRODUCTION: Phenolic compounds present in Achyrocline satureioides are known to have therapeutic benefits like antioxidant, anti-inflammatory, and antitumour properties. The main polyphenols present in the plant are quercetin (QCT), luteolin (LUT), 3-O-methylquercetin (3OMQ), and achyrobichalcone (ACB). However, the effective isolation and purification of these compounds from A. satureioides inflorescences are not an easy task. OBJECTIVE: To develop an efficient high-performance counter-current chromatography (HPCCC) method for quick separation and purification of naturally occurring phenolic compounds from the extract of A. satureioides. METHODOLOGY: A two-step HPCCC semi-preparative isolation method was developed using a solvent system composed of n-hexane/ethyl acetate/methanol/water (0.8:1.0:0.8:1.0) and dichloromethane/methanol/water (3.5:3.5:2.5). RESULTS: The HPCCC method was used to obtain two fractions. The first fraction (F1 ) contained high levels of ACB, among other constituents, while the second fraction (F2 ) contained mostly QCT, LUT, and 3OMQ. Besides the high ACB content, F1 contained three other flavonoid-aglycones (kaempferol, 97.3%; isokaempferide, 92.4%; and 3,3'-di-O-methylquercetin, 95.2%) identified by an ultra-performance liquid chromatography system coupled to a quadrupole time-of-flight with high-definition mass spectrometry (UPLC-QTOF/HDMS) and nuclear magnetic resonance (NMR) analysis. Purity levels of ACB, 3OMQ, QCT, and LUT were 98.0, 97.0, 97.5, and 90.2%, respectively. CONCLUSION: This is the first time that high purity ACB and six other flavonoids were obtained from A. satureioides inflorescences by HPCCC. These excellent results reveal the potential and versatility of HPCCC as a technique to produce different types of products from this plant species on a semi-preparative scale: enriched fractions, new metabolites, or high purity compounds.

Ultrasound-assisted extraction of Achyrocline satureioides prevents contrast-induced nephropathy in mice.

Achyrocline satureioides or Macela, has been largely used in traditional folk medicine in Brazil as an anti-inflammatory agent and to treat various digestive disorders. The aim of the present study was to evaluate the preventive action of the extracts of A. satureioides obtained by maceration and ultrasound-assisted extraction, quercetin and N-acetylcysteine against contrast-induced nephropathy in mice. The antioxidant activity, cytotoxicity and inhibition of nitric oxide (NO) production in macrophages were evaluated. Also, chemical analyses of phenolic compounds, total flavonoids, and quercetin by LC-MS/MS present in various extracts of A. satureioides were performed. Thirty six mice were divided into six groups: control group (C), Contrast-Induced Nephropathy group (CIN), Group N-acetylcysteine 200mg/kg (NAC); Group quercetin 10mg/kg (Q), Group Macela 10mg/kg (M10), and Group Macela 50mg/kg (M50). The serum levels of urea and creatinine, advanced oxidation protein products (AOPP) and renal ultrastructure were evaluated by electron microscopy scanning. Ultrasound-assisted extraction improved the quality of extract (with 100% ethanol), since did not show toxicity to fibroblasts, and showed potent antioxidant activity and a high content of phenolic compounds, flavonoids, and quercetin, in addition to being able to reduce the production of NO in dose-dependent effect in macrophages. Results showed that animals treated with Macela extracts maintained normal levels of urea, creatinine, and AOPP, while preserving ultrastructure of the renal cells. The obtained results were more promising than NAC and Q groups in protecting against renal failure caused by CIN, showing that the plant can be a promising drug for preventing this disease.

Achyrocline satureioides essential oil loaded in nanocapsules ameliorate the antioxidant/oxidant status in heart of rats infected with Trypanosoma evansi.

Oxidative stress has been considered as a pathological mechanism that contributes to initiation and progression of cardiac injury during the Trypanosoma evansi infection. In this sense, the natural compounds with antioxidant and free radical scavenger abilities, such the Achyrocline satureioides essential oil loaded in nanocapsules (AS-NC), may be considered important approach to minimize the cardiac damage. Thus, the aim of this study was to investigate whether AS-NC treatment is able to prevents or reduce the cardiac oxidative damage in infected rats with T. evansi. Heart samples from rats infected by T. evansi showed increased reactive oxygen species (ROS), thiobarbituric reactive-acid substances (TBARS) and glutathione reduced (GSH) levels, while catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities decreased compared with uninfected and untreated animals. Also, the seric biomarkers of cardiac function increased in the infected animals compared with uninfected animals. AS-NC treatment reduced ROS and TBARS levels, ameliorate cardiac CAT and SOD activities of infected rats, and reduced seric biomarkers of cardiac function. AS-NC treatment protected the heart from oxidative stress caused by T. evansi, which might be due to its antioxidant properties. AS-NC might be considered a promising therapeutic agent against oxidative stress, when associated with nanotechnology.

Achyrocline satureioides essential oil-loaded in nanocapsules reduces cytotoxic damage in liver of rats infected by Trypanosoma evansi.

The aim of this study was to evaluate whether the treatment with Achyrocline satureioides essential oil-loaded in nanocapsules (AS-NC) is able to protect the hepatic tissue against cytotoxic damage caused by Trypanosoma evansi. Thus, the rats were divided into four groups (n = 6 per group): uninfected/saline, uninfected/AS-NC, infected/saline, and infected/AS-NC. At day 4 post-infection (PI), the animals were euthanized and liver and sera samples were collected to perform the hepatic cell viability assay, and to determine seric levels of reactive oxygen species (ROS) and nitric oxide metabolites (NOx). Cell viability decreased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this alteration in infected rats. Seric ROS and NOx levels increased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this effect on ROS levels of infected rats. In summary, the treatment with AS-NC was able to protect the liver tissue against the cytotoxic effect caused by the parasite by avoiding exacerbated production of ROS.

Protective effect of a hydrogel containing Achyrocline satureioides extract-loaded nanoemulsion against UV-induced skin damage.

Achyrocline satureioides is a medicinal plant widely used in South America that exhibits a well-documented antioxidant activity. Such activity has been related to their main aglycone flavonoids quercetin, luteolin, and 3-O-methylquercetin (3MQ). This study addresses the development of antioxidant hydrogels containing an A. satureioides extract-loaded nanoemulsions aimed at topical application. The systems investigated were A. satureioides extract-loaded nanoemulsions (ASNE) obtained by spontaneous emulsification procedure formulated in semisolid hydrogels composed of Carbopol® Ultrez 20 (HASNE). Hydrogels exhibit a non-Newtonian pseudoplastic behavior. A higher release of 3MQ from ASNE (3.61µg/cm(2)/h) was observed when compared with HASNE (2.83µg/cm(2)/h). Different parameters that may have an influence on the retention of flavonoids into the skin were investigated by using a Franz-type diffusion cells. Indeed, the amount of formulation applied on donor compartment was found to play a crucial role. At the optimized conditions, retention of approximately 2µg/cm(2) of flavonoids was detected into the skin. A higher retention of 3MQ was detected (approximately 1.0µg/cm(2)) in comparison with the other flavonoids. Finally, a protection the porcine ear skin by formulations, against oxidative stress generated by UVA/UVB light was demonstrated by means of TBARS, protein carbonylation, and protein thiol content assays. The overall results showed the potential of the formulations developed in this study for the prevention of oxidative stress on the skin.

In vitro and in silico antioxidant and toxicological activities of Achyrocline satureioides.

ETHNOPHARMACOLOGICAL RELEVANCE: Achyrocline satureioides ("macela or marcela") is a medicinal plant, traditionally collected in "Good Friday" before sunrise. In traditional medicine, dried flowers of A. satureioides are used as anti-dyspeptic, antispasmodic and anti-inflammatory. AIM OF THE STUDY: To evaluate the phytochemical profile and to present an in vitro and in silico approach about toxicity and antioxidant potential of A. satureioides flowers extract and its major phytoconstituents. MATERIALS AND METHODS: Plant were collected according to the popular tradition. Extract were obtained by infusion and analyzed from high-performance liquid chromatography. Toxicity was evaluated in Artemia salina and human lymphocytes. Extract antioxidant activity was determined with total antioxidant capacity, DPPH• and ABTS+• scavenging, ferric reducing antioxidant power, deoxyribose degradation assay, and thiobarbituric acid reactive substances (TBA-RS) assay. TBA-RS inhibitions were evaluated in brain of rats for A. satureioides extract and its major phytoconstituents. Predictions of activity spectra for substances and in silico toxicity evaluation from major phytoconstituents were performed via computer simulation. RESULTS: Chromatographic data indicated isoquercitrin, quercetin and caffeic acid as main compounds in flowers extract. Toxicity tests demonstrated a very low toxic potential of A. satureioides. Extract exhibited antioxidant activities in low concentrations. Both extract and major phytochemicals standards showed protection against lipid peroxidation in brain of rats. Computer simulations pointed some biological activities in agreement with traditional use, as well as some experimental results found in this work. Moreover, in silico toxic predictions showed that the A. satureioides major compounds had low probability for toxic risk. CONCLUSION: Our results indicate that A. satureioides infusion possesses low toxicological potential and an effective antioxidant activity. These findings confirm the traditional use of this plant in the folk medicine.

Chemical composition and biological activity of essential oil of achyrocline ramosissima briton ex rusby (asteraceae) / Composición química y actividad biológica del aceite esencial de achyrocline ramosissima britton ex rusby (asteraceae)

Essential oil from fresh aerial parts of Achyrocline ramosissima Britton ex Rusby (Asteraceae) collected in the Venezuelan Andes was obtained by hydrodistillation and analyzed by GC/MS. A yield of 0.10 percent w/v was afforded, and thirty seven components were identified by comparison of their retention indices (RI) and mass spectra with the Wiley GC-MS Library Data. The major components identified were rosifoliol (31.69 percent), beta-caryophyllene (8.61 percent), guaiol (3.95 percent), beta-eudesmol (3.33 percent) and selina-3,7 (11)-diene (2.99 percent). Antimicrobial activity of A. ramosissima essential oil was also evaluated against Gram positive, Gram negative bacterial strains and Candida albicans yeast. The results showed that, this oil is effective against Gram positive bacteria Staphylococcus aureus ATCC 6538 with MIC values ranging from 50 to 100 μg/mL and MBC values > 200 μg/mL as well as Bacillus subtilis CECT 39 with MIC values of 50 μg/mL and MBC of 100 μg/mL, however a low activity was observed against Gram negative bacterial strains, Pseudomonas aeruginosa AK 958, Escherichia coli CECT 99 and C. albicans yeast performing MIC and MBC values > 200 μg/mL. Cytotoxic activity was also determined against HeLa (cervix carcinoma), A-459 (lung carcinoma), MCF-7 (breast adenocarcinoma) human cancer cell lines and against normal Vero cells (African green monkey kidney), exhibiting antiproliferative effects with IC50 values of 28.2 μg/mL (HeLa cells). This is the first report regarding the chemical composition, antibacterial and cytotoxic activities of the essential oil from this species.

El aceite esencial de las partes aéreas frescas de Achyrocline ramosissima Britton ex Rusby (Asteraceae) recolectada en los Andes venezolanos fue extraído por hidrodestilación y analizado por CG/EM. Se obtuvo un rendimiento de 0,10 por ciento m/v, treinta y siete componentes fueron identificados por comparación de los índices de retención (IR) y sus espectros de masas con los datos de la biblioteca Wiley GC-MS. Los principales componentes identificados fueron rosifoliol (31,69 por ciento), beta-cariofileno (8,61 por ciento), guaiol (3,95 por ciento), beta-eudesmol (3,33 por ciento) y selina-3,7 (11)-dieno (2,99 por ciento). La actividad antimicrobiana del aceite esencial de A. ramosissima fue evaluada contra cepas bacterianas Gram positivas, Gram negativas y la levadura Candida albicans. Los resultados mostraron que el aceite esencial fue activo contra las bacterias Gram positivas Staphylococcus aureus ATCC 6538 con una CIM entre 50-100 μg/mL y CBM de valores > 200 μg/mL y Bacillus subtilis CECT 39 con CIM de 50 μg/mL y CBM de 100 μg/mL, sin embargo se observó una baja actividad contra las cepas bacterianas Gram negativas Pseudomonas aeruginosa AK 958, Escherichia coli CECT 99 y la levadura C. albicans cuyos valores de CIM y CBM fueron > 200 μg/mL. La actividad citotóxica fue determinada frente a las líneas celulares cancerígenas HeLa (carcinoma de cuello uterino), A-459 (carcinoma de pulmón), MCF-7 (adenocarcinoma de mama) y frente a las células normales Vero (células renales de mono verde), mostrando efectos antiproliferativos con valores de CI50 28.2 μg/mL frente a las células HeLa. Este es el primer reporte sobre la composición química, actividad antibacteriana y citotóxica del aceite esencial de esta especie.

Antioxidant Effect of Nanoemulsions Containing Extract of Achyrocline satureioides (Lam) D.C.-Asteraceae.

Ethanolic extracts of Achyrocline satureioides have pronounced antioxidant activity mainly due to the presence of the flavonoid quercetin. However, direct topical application of the extract is not possible due to the presence of high amounts of ethanol. In this sense, nanoemulsions arise as an alternative for topical formulation associating molecules with limited aqueous solubility. This article describes the development of topical nanoemulsions containing either A. satureioides extract or one of its most abundant flavonoid, quercetin. Nanoemulsions composed of octyldodecanol, egg lecithin, water and extract (NEE), or quercetin (NEQ) were prepared by spontaneous emulsification. This process led to monodisperse nanoemulsions presenting a mean droplet size of approximately 200-300 nm, negative zeta potential, and high association efficiency. A study of quercetin skin retention using porcine skin which was performed using a Franz diffusion cell revealed a higher accumulation of quercetin in skin for NEE when compared to NEQ. Finally, the antioxidant activity of formulations was measured by thiobarbituric acid-reactive species and the APPH model. A lower lipoperoxidation for the extract in respect to quercetin solution was observed. However, no difference between NEQ and NEE lipoperoxidation could be seen. The protection against lipoperoxidation by the formulations was also measured in the skin, where lower formation of reactive species was observed after treatment with NEE. In conclusion, this study shows the formulation effect on the physicochemical properties of nanoemulsions as well as on the skin retention and antioxidant activity of quercetin.

In vitro antiviral activity against rotavirus and astrovirus infection exerted by substances obtained from Achyrocline bogotensis (Kunth) DC. (Compositae).

BACKGROUND: Achyrocline bogotensis has been traditionally used to treat infections of skin, respiratory, tract urinary and other infections, but not to treat viral gastrointestinal disease. In this study, this Colombian native medicinal plant was investigated by its in vitro anti-rotavirus and anti-astrovirus activity. METHODS: Several extracts and fractions phytochemically obtained from A. bogotensis were evaluated initially for their cell toxicity on MA104 and Caco2 cells and then for their anti-rotavirus (RRV) and anti-astrovirus (Yuc8) activity following three strategies: pre-treatment of cells (blocking effect), direct viral activity (virucidal effect) and post-treatment of infected cells (reduction of viral yield post-infection). In addition qualitative chemical studies were developed for the active compounds. RESULTS: Non-toxic concentrations of a fraction obtained exhibited antiviral activity against both viruses characterized by a virucidal effect and by the reduction of the infectious particles produced post-infection. Steroids, sterols, terpenes, phenols, flavonoids and sesquiterpenlactones were identified qualitatively in the active fraction. CONCLUSIONS: A. bogotensis contains substances with in vitro antiviral activity against rotavirus and astrovirus. This study confirms their anti-microbial properties and describes by the first time its antiviral activity in vitro.

Antiherpes Activity and Skin/Mucosa Distribution of Flavonoids from Achyrocline satureioides Extract Incorporated into Topical Nanoemulsions.

This study investigated the inhibitory effects of Achyrocline satureioides extract (ASE) incorporated into a topical nanoemulsion on Herpes Simplex Virus type 1 (HSV-1/KOS strain) replication, as well as the distribution of the main ASE flavonoids (quercetin, luteolin, and 3-O-methylquercetin) in porcine skin and mucosa. The ASE-loaded nanoemulsion showed more pronounced effects against HSV-1 replication when compared to the ASE or pure quercetin, as determined by the viral plaque number reduction assay. All flavonoids were detected in the skin epidermis (2.2 µg/cm(2)) and the mucosa upper layers (3.0 µg/cm(2)) from ASE-loaded nanoemulsion until 8 h after topical application. A higher amount of flavonoids was detected when these tissues were impaired, especially in deeper mucosa layers (up to 7-fold). Flavonoids were detected in the receptor fluid only when the mucosa was injured. Such results were supported by confocal microscopy images. Overall, these findings suggest that the tested ASE-loaded nanoemulsion has potential to be used topically for herpes infections.