Kinetics and modeling of cell growth for potential anthocyanin induction in cultures of Taraxacum officinale G.H. Weber ex Wiggers (Dandelion) in vitro

Background: Taraxacum officinale G.H. Weber ex Wiggers is a wild plant used in folk medicine to treat several diseases owing to bioactive secondary metabolites present in its tissue. The accumulation of such molecules in plant cells can occur as a response against abiotic stress, but these metabolites are often deposited in low concentrations. For this reason, the use of a biotechnological approach to improve the yields of technologically interesting bioactive compounds such as anthocyanins is a compelling option. This work focuses on investigating the potential of in vitro T. officinale cultures as an anthocyanin source. Results: To demonstrate the suitability of anthocyanin induction and accumulation in calluses under specific conditions, anthocyanin was induced in the T. officinale callus. A specific medium of 5.5% sucrose supplemented with 6-benzylaminopurine /1-naphthaleneacetic acid in a 10:1 ratio was used to produce an anthocyanin yield of 1.23 mg g-1 fw. An in vitro dandelion callus line was established from this experiment. Five mathematical models were then used to objectively and predictably explain the growth of anthocyanin-induced calluses from T. officinale. Of these models, the Richards model offered the most suitable representation of anthocyanin callus growth in a solid medium and permitted the calculation of the corresponding kinetic parameters. Conclusions: The findings demonstrate the potential of an in vitro anthocyanin-induced callus line from T. officinale as an industrial anthocyanin source.

Taraxacum: Phytochemistry and health benefits / 中草药·英文版

Taraxaci Herba (Taraxacum mongolicum and other species) has been used in traditional Chinese medicine and dietary application for a long history in China, and Taraxacum officinale has been applied in medicinal and food use in other regions and cultures around the globe. In this review, the phytochemical constituents of dandelion (particularly from T. mongolicum and T. officinale) were summarized. Recent published health benefits of dandelion, such as anti-oxidant activity, anti-inflammatory activity, blood sugar and lipids regulation and hepatoprotective activity, as well as its safety data were highlighted. The limited human clinical study and pharmacokinetics information lead to the thought that well-designed human clinical study should be the focus and opportunity for the future research area to truly understand efficacy function and health benefit of dandelion for its application in medicine and health food area.

Concentraciones de alcaloides, glucósidos cianogénicos, polifenoles y saponinas en plantas medicinales seleccionadas en Ecuador y su relación con la toxicidad aguda contra Artemia salina / Concentrations of alkaloids, cyanogenic glycosides, polyphenols and saponins in selected medicinal plants from Ecuador and their relationship with acute toxicity against Artemia salina

ResumenEntre los principales compuestos químicos sintetizados por las plantas, pero considerados no esenciales para su metabolismo básico, están los alcaloides, los polifenoles, los glucósidos cianogénicos y las saponinas que tienen diversas funciones en las plantas y reconocidas propiedades medicinales y farmacológicas. En esta investigación se determinaron las concentraciones de los mencionados metabolitos secundarios en los extractos de las hojas de las plantas medicinales Taraxacum officinale, Parthenium hysterophorus, Artemisia absinthium, Cnidoscolus aconitifolius y Piper carpunya y se relacionaron con la toxicidad aguda contra Artemia salina. En cada bioensayo con A. salina se usaron los extractos alcohólicos de las hojas de las plantas seleccionadas a diferentes concentraciones, calculándose la proporción de organismos muertos y los CL50. Las concentraciones de alcaloides, fenoles totales, taninos, glucósidos cianogénicos y saponinas fueron determinadas mediante métodos espectrofotométricos. Este es el primer reporte de cuantificación de metabolitos secundarios en las plantas analizadas provenientes de Ecuador. T. officinale presentó las mayores concentraciones de fenoles (22.30 ± 0.23 mg/g) y taninos (11.70 ± 0.10 mg/g), C aconitifolius de glucósidos cianogénicos (5.02 ± 0.37 µg/g) y P. hysterophorus de saponinas (6.12 ± 0.02 mg/g). Las plantas evaluadas presentaron actividades hemolíticas dependiendo de las concentraciones de saponinas. Los valores de taninos determinados estuvieron entre 0.20 ± 0.01 y 11.70 ± 0.10 mg/g, por lo que no son adversos para su consumo. Aunque los valores de glucósidos cianogénicos son permisibles, es necesario monitorear la presencia de estos compuestos químicos en las plantas para minimizar problemas de salud. Los CL50 obtenidos oscilaron entre los valores 3.37 µg/mL, extremadamente letal o tóxica, para P. carpunya y 274.34 µg/mL, altamente tóxica, para T. officinale. De los análisis de correlaciones realizados a los resultados, se observó que los alcaloides favorecen de manera significativa (p<0.001) a la toxicidad aguda contra A. salina, mientras que a mayor contenido de polifenoles dicha toxicidad disminuye significativamente (p<0.001) el nivel de toxicidad de las plantas. Del análisis de componentes principales, se demuestra que las saponinas están en sinergia con los polifenoles para disminuir la toxicidad, pero tienen un efecto antagónico con los alcaloides y los glucósidos cianogénicos, lo cual evidencia que estos metabolitos secundarios presentan variabilidades en los mecanismos de acción contra A. salina, como compuestos citotóxicos. Estos resultados demuestran que las saponinas y los polifenoles pueden ser letales para A. salina a bajas concentraciones, evidenciando que este bioensayo permite evaluar extractos vegetales que contengan bajas concentraciones de compuestos con altas polaridades. La correspondencia significativamente positiva entre citoxicidad y concentración de los alcaloides, confirmada con el bioensayo de Artemia salina, puede ser útil para hallar fuentes promisorias de compuestos antitumorales y para evaluar los límites tolerables que no afecten otras células benignas. El contenido de metabolitos secundarios hallados en las plantas analizadas les atribuye un gran valor farmacológico.

Abstract:Alkaloids, polyphenols, cyanogenic glycosides and saponins are among the main chemical compounds synthesized by plants but not considered essential for their basic metabolism. These compounds have different functions in plants, and have been recognized with medicinal and pharmacological properties. In this research, concentrations of the mentioned secondary metabolites were determined in the medicinal plants Artemisia absinthium, Cnidoscolus aconitifolius, Parthenium hysterophorus, Piper carpunya and Taraxacum officinale, from Ecuador, and related with cytotoxic effects against Artemia salina. Alcoholic and aqueous extracts from leaves of these selected plants were prepared at different concentrations. To assess cytotoxicity of these extracts, different bioassays with A. salina were undertaken, and the mortality rates and LC50 were obtained. Besides, concentrations of alkaloids, cyanogenic glycosides, phenols, tannins and saponins were determined by spectrophotometric methods; this constituted the first report of quantification of secondary metabolites in the selected plants from Ecuador. T. officinale had the highest concentration of total phenols (22.30 ± 0.23 mg/g) and tannins (11.70 ± 0.10 mg/g), C. aconitifolius of cyanogenic glycosides (5.02 ± 0.37 µg/g) and P. hysterophorus of saponins (6.12 ± 0.02 mg/g). Tannins values obtained were not adverse to their consumption. Alcoholic and aqueous extracts of selected plants had hemolytic activity depending on the concentration of saponins. Although the values of cyanogenic glycosides were permissible, it was necessary to monitor the presence of this metabolite in plants to minimize health problems. LC50 values ranged from extremely toxic (3.37 µg/mL) to highly toxic (274.34 μg/mL), in P. carpunya and T. officinale, respectively. From correlation analysis, it was observed that increase values of alkaloids concentrations had highly significant (p<0.001) acute toxicity against A. salina, while at a higher polyphenol concentration the level of plants cytotoxicity decreased significantly (p<0.001). The results of principal component analysis showed that saponins apparently were in synergy with polyphenols to decrease cytotoxicity, but antagonize with alkaloids and cyanogenic glycosides, indicating that these secondary metabolites present variability in the mechanisms of action against A. salina, as cytotoxic compounds. These results also demonstrate that polyphenols and saponins can be lethal at low concentrations, demonstrating the potential of brine shrimp bioassay as a model to evaluate plant extracts containing low concentrations of chemical compounds with high polarities. The significant positive correlation between cytotoxicity and concentration of alkaloids confirmed by the bioassay of brine shrimp can be useful to identify promising sources of antitumor compounds, and to evaluate tolerable limits not affecting other benign cells. Contents of secondary metabolites found in the selected plants confer them great pharmacologic values. Rev. Biol. Trop. 64 (3): 1171-1184. Epub 2016 September 01.

Hepatoprotective properties of Dandelion: recent update.

Taraxacum officinalis (Dandelion) have been used as folk medicines in China, India, and Russia for the treatment of chronic liver diseases. This review focuses exclusively on published literature pertaining to the potential use of Taraxacum officinalis or Dandelion for the treatment of various chronic liver diseases. Dandelion has been tested against various drugs and chemical induced chronic liver diseases in experimental animals and came out with promising results. In vitro studies also confirm the hepatoprotective, antioxidant and anti-inflammatory properties of dandelion. The extensive literature survey reveal the fact that Taraxacum officinalis or dandelion to be safe and the available evidence on the mechanisms of action appears promising, there are currently insufficient data from well-conducted clinical trials to recommend it use in patients with alcoholic liver chronic liver disease.

Cross-allergenicity between dandelion and major weed pollens

PURPOSE: The prevalence of pollinosis is increasing, and it is expected to increase further with climate change. Mugwort and ragweed pollens are well known as prevalent allergenic weed pollens in Korea. However, the clinical significance of dandelion pollen as an inhalant allergen has not yet been studied. The purpose of this study was to evaluate the clinical significance and cross-allergenicity between dandelion and major weed pollens. METHODS: Ninety-seven patients with allergic rhinitis and asthma or with allergic rhinitis alone who were sensitized to dandelion pollens on skin prick tests (allergen/histamine ratio>3) were enrolled between December, 2012 and November, 2013. Serum specific IgE levels to dandelion pollen extracts were measured by using enzyme-linked immunosorbent assay (ELISA). ELISA inhibition tests were performed to evaluate cross allergenecity with other weed pollens. RESULTS: When the positive cutoff value for serum specific IgE was set at the mean+/-3 standard deviation of absorbance values, 52 patients (53.6%) had a high serum specific IgE antibody level. ELISA inhibition tests showed significant inhibitions with serial addition of dandelion pollen extracts, and 5 different inhibition patterns were noted with addition of 4 weed pollen extracts: significant inhibitions with pollens of mugwort, ragweed, chenopodium and Hop J (25%, 13 of 52), inhibitions with pollens of mugwort, ragweed and chenopodium (17.3%, 9 of 52), inhibitions with 2 pollens of mugwort and ragweed (32.6%, 17 of 52), inhibitions with mugwort pollen (21.1%, 11 of 52), and inhibitions with dandelion pollen alone (4%, 2 of 52). CONCLUSION: These findings suggest that dandelion pollen may be a causative inhalant allergen to induce pollinosis in the autumn season. Cross-allergenicity with other weed pollens showed individual differences; most patients had cross-reactivity with mugwort, ragweed, and chenopodium pollens, while some with Hop J pollen. Few patients were sensitized to dandelion pollen alone.

Microscopical descriptions and chemical analysis by HPTLC of Taraxacum officinale in comparison to Hypochaeris radicata: a solution for mis-identification

Taraxacum officinale F. H. Wigg, Asteraceae, is frequently misidentified or substituted with Hypochaeris radicata L., Asteraceae (false dandelion). To increase our knowledge of T. officinale and differentiate it from H. radicata, we investigated the two species using a combination of taxonomy, microscopy, and chromatographic studies via fingerprint profiles. Micromorphological characteristics were studied using scanning electron microscopy, while optic light microscopy was used for histochemical observations. Fingerprint profiles were constructed using HPTLC. T. officinale was found to have a morphologically distinct type of pluricellular trichomes that can be used to differentiate the two species, as these structures were not identified in H. radicata samples. Furthermore, two types of laticiferous vessels may also be distinctive characteristics of T. officinale at species level. In addition, the HPTLC data derived from methanolic extracts of H. radicata and T. officinale roots showed clearly different chemical profiles. Thus this study establishes the authenticity of T. officinale, and the observed parameters could help minimize drug substitutions in herbal medicines.

An in vitro analysis of antiproliferative and antimicrobial activities of solvent fractions of Taraxacum officinale (Dandelion) leaf.

The persistent upsurge in multidrug resistance of common pathogens and global increase in the incidence of noninfectious diseases such as cancers and diabetes has led to an urgent need for the discovery of novel and affordable pharmaceuticals. Taraxacum officinale commonly called dandelion has been used in traditional medicine for the treatment of various conditions. Although the antimicrobial and antiproliferative properties of various crude extracts of T. officinale have been reported, there is little report on the antimicrobial and antiproliferative activities of its solvent fractions. In this study, various solvent fractions from the crude methanolic extract of T. officinale leaves were examined for their antiproliferative and antimicrobial activities with the aim of providing a baseline data for the discovery of the antiproliferative and antimicrobial phytocompounds in T. officinale leaves. Whereas, methylene chloride fraction showed the highest antiproferative activity, inhibiting 97 % proliferation of SGT oral cancer cells the butanol fraction showed the highest antimicrobial activity in both disc diffusion and broth dilution assays. Therefore the methylene chloride and the butanolic fractions could respectively act as leads for the discovery of important anticancer and antimicrobial phytocompounds from T. officinale.

Actividad antiviral contra el virus de la fiebre amarilla, cepa vacunal 17D, de extractos de hojas de Taraxacum officinale GH Weber ex Wiggers / Phytochemicaland antiviral activity against yellow fever virus, 17D vaccine strain, of extracts from leaves of Taraxacum officinale GH Weber ex Wiggers

Taraxacum officinale leaves were collected at two and 5 months of growth, for antiviral activity against flavivirus, using the 17D vaccine strain of yellow fever virus as a model. Using spectroscopy technique, a total of twelve (12) compounds were identified in the chloroform (C) and hexane (H) extracts of two and five months (2M and 5M) of recollection., The antiviral activity against the yellow fever 17D virus was evaluated with the plaque assay and the concentrations used (50 - 1,5 ug/mL) were no cytotoxic to Vero cells as determined using the MTT(3-(4,5-Dimetiltiazol-2yl)-2,4-difenilbromuro de tetrazolium) assay. The phytochemical composition of leaves growing for 5 months is different and more complex than leaves growing for 2 months. From the four extracts, only C5M inhibited the viral replication in a dose depend manner, with 100 percent viral inhibition at 50 ug/mL (p=0,0124) and the effective doses 50 (ED50: 10,2 +/- 8,7 ug/mL), meanwhile, ED50 of C2M extract was 93,5 +/- 23,5 ug/mL, thus, the extract C5M is 8 times more effective than extract C2M. The identified compounds in extract C5M were: Psi taraxasteryl acetate, cafeic acid, taraxasteryl acetate, taraxerol, taraxerilo acetate and Psi-taraxasterol. One of these compounds or the combinations of them is responsible for the reported high antiviral activity.

Las hojas de Taraxacum officinale fueron colectadas a dos y cinco meses de crecimiento, para determinar actividad antiviral contraflavivirus, utilizando como modelo el virus de fiebre amarilla cepa vacunal 17D. Se identificaron por métodos espectroscópicos, un total de doce (12) compuestos provenientes de los extractos de hexano (H) y cloroformo (C) a dos y cinco meses (2M y 5M) de recolección La actividad antiviral se determinó mediante un ensayo de placa y las concentraciones de extractos utilizadas (50-1,5 ug/mL) fueron no citotóxica en células Vero, determinadas por el método colorimétrico del MTT (3-(4,5-Dimetiltiazol-2yl)-2,4-difenilbromuro de tetrazolio). La composición fitoquímica de los extractos de 5 meses es distinta y más compleja que la de dos meses de crecimiento. De los cuatro extractos sólo el C5M inhibió la replicación del virus en una manera dosis dependiente, con una inhibición del 100 por ciento a 50 ug/mL (p=0,0124) y una dosis efectiva 50 (DE50) de 10,2 +/- 8,7 ug/mL, mientras que el DE50 del extracto C2M es de 93,5 +/- 23,5 ug/mL, lo que hace al extracto clorofórmico de 5 meses aproximadamente 8 veces más efectivo que el C2M. Los compuestos presentes en el extracto C5M son Psi taraxasterilo, ácido cafeíco, acetato de taraxasterilo, taraxerol, acetato de taraxerilo y Psi-taraxasterol. Uno o más de estos compuestos son responsables de alta actividad antiviral reportada.

Pancreatic lipase inhibitory activity of taraxacum officinale in vitro and in vivo

Obesity has become a worldwide health problem. Orlistat, an inhibitor of pancreatic lipase, is currently approved as an anti-obesity drug. However, gastrointestinal side effects caused by Orlistat may limit its use. In this study the inhibitory activities of dandelion (Taraxacum officinale) against pancreatic lipase in vitro and in vivo were measured to determine its possible use as a natural anti-obesity agent. The inhibitory activities of the 95% ethanol extract of T. officinale and Orlistat were measured using 4-methylumbelliferyl oleate (4-MU oleate) as a substrate at concentrations of 250, 125, 100, 25, 12.5 and 4 microgram/ml. To determine pancreatic lipase inhibitory activity in vivo, mice (n=16) were orally administered with corn oil emulsion (5 ml/kg) alone or with the 95% ethanol extract of T. officinale (400 mg/kg) following an overnight fast. Plasma triglyceride levels were measured at 0, 90, 180, and 240 min after treatment and incremental areas under the response curves (AUC) were calculated. The 95% ethanol extract of T. officinale and Orlistat, inhibited, porcine pancreatic lipase activity by 86.3% and 95.7% at a concentration of 250 microg/ml, respectively. T. officinale extract showed dose-dependent inhibition with the IC50 of 78.2 microg/ml. A single oral dose of the extract significantly inhibited increases in plasma triglyceride levels at 90 and 180 min and reduced AUC of plasma triglyceride response curve (p<0.05). The results indicate that T. officinale exhibits inhibitory activities against pancreatic lipase in vitro and in vivo. Further studies to elucidate anti-obesity effects of chronic consumption of T. officinale and to identify the active components responsible for inhibitory activity against pancreatic lipase are necessary.