Biological Evaluation of Valeriana Extracts from Argentina with Potent Cholinesterase Inhibition for the Treatment of Neurodegenerative Disorders and Their Comorbidities-The Case of Valeriana carnosa Sm. (Caprifoliaceae) Studied in Mice.

Alzheimer's disease (AD) is a neurodegenerative disorder whose pathophysiology includes the abnormal accumulation of proteins (e.g., ß-amyloid), oxidative stress, and alterations in neurotransmitter levels, mainly acetylcholine. Here we present a comparative study of the effect of extracts obtained from endemic Argentinian species of valerians, namely V. carnosa Sm., V. clarionifolia Phil. and V. macrorhiza Poepp. ex DC from Patagonia and V. ferax (Griseb.) Höck and V. effusa Griseb., on different AD-related biological targets. Of these anxiolytic, sedative and sleep-inducing valerians, V. carnosa proved the most promising and was assayed in vivo. All valerians inhibited acetylcholinesterase (IC50 between 1.08-12.69 mg/mL) and butyrylcholinesterase (IC50 between 0.0019-1.46 mg/mL). They also inhibited the aggregation of ß-amyloid peptide, were able to chelate Fe2+ ions, and exhibited a direct relationship between antioxidant capacity and phenolic content. Moreover, V. carnosa was able to inhibit human monoamine oxidase A (IC50: 0.286 mg/mL (0.213-0.384)). A daily intake of aqueous V. carnosa extract by male Swiss mice (50 and 150 mg/kg/day) resulted in anxiolytic and antidepressant-like behavior and improved spatial memory. In addition, decreased AChE activity and oxidative stress markers were observed in treated mouse brains. Our studies contribute to the development of indigenous herbal medicines as therapeutic agents for AD.

Dynamics of Polyphenol Biosynthesis by Calli Cultures, Suspension Cultures and Wild Specimens of the Medicinal Plant Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae). Analysis of Their Biological Activity.

Ligaria cuneifolia (R. et P.) Tiegh. (Loranthaceae) is a South American hemiparasitic species with antioxidant, antitumoral, antimicrobial, and antilipidemic activities attributed to its polyphenolic content. We studied the polyphenolic pattern of L. cuneifolia during different phenological stages: flowering, fruiting, and post-fruiting. The highest total phenolic content was found in stems at post-fruiting (214 ± 12.1 mg gallic acid eq·g-1 DW) and fruiting (209 ± 13.7 mg gallic acid eq·g-1 DW), followed by post-fruiting leaves (207 ± 17.5 mg gallic acid eq·g-1 DW). Flavonoids accumulated at higher levels in leaves and hydroxycinnamic acids in leaves at flowering and post-fruiting. The polyphenolic pattern was similar between organs from wild plants and in vitro cultures, although at a significantly lower level in the latter ones. The performance of calli growing under a 16 h photoperiod in a modified White medium with 1-naphthalene acetic acid (2.50 µM) and Kinetin (9.20 µM) was better than in the dark. When calli grew in media only with auxins (IAA, NAA, and 2,4-D, all at 2.50 µM concentration), its growth and polyphenolic content improved. Cell suspensions with 2.50 µM NAA and 9.20 µM KIN grew slowly and produced very small amounts of polyphenols. As for the antioxidant activity, it was detected in all samples (approximately 1000 µmol trolox eq·g-1 DW) except fruits, where a lower value was found (328 µmol trolox eq·g-1 DW). In vitro cultures have the lowest antioxidant activity when compared to methanolic extracts from organs of wild specimens. Finally, antimutagenic or mutagenic activity in wild plants and in vitro culture extracts was not detected by the Ames test.

Inhibitory effect of medicinal herbs against RNA and DNA viruses.

Fifteen Argentine medicinal plants were tested for their antiviral activity in vitro against herpes simplex viruses types 1 and 2 (HSV-1 and 2), bovine viral diarrhoea virus type 1 (BVDV-1), influenza virus type A (Inf A) and human immunodeficiency virus type 1 (HIV-1). Antiviral activity was evaluated by a reduction in cytopathic effect, plaque-forming units and p24 HIV-1 antigen. The Selective Index of the active extract (SI(extract) = CC50(extract)/EC50(extract)) of Coronopus didymus (SI(extract) = 110.7), Juglans australis (SI(extract) = 8.1) and Lippia alba (SI(extract) = 19.2) against BVDV-1, HSV-1 and influenza A virus, respectively, justify a further analysis. None of the seven plants assayed against HIV-1 displayed any antiviral activity. The results of this study justify the continuing isolation and characterization of the antiviral components present.

In vitro tissue culture, preliminar phytochemical analysis, and antibacterial activity of Psittacanthus linearis (Killip) J.K. Macbride (Loranthaceae) / Cultivo de tejidos in vitro, análisis fitoquímico preliminar y actividad antibacteriana de Psittacanthus linearis (Killip) J.K. Macbride (Loranthaceae)

ABSTRACT Hemiparasitic plants commonly known as mistletoe (muérdago in Spanish) in the families Santalaceae and Loranthaceae are common in various kinds of plants or trees, and many hemiparasitic plants are used for medicinal purposes in various parts of the world. The objective of the present work, carried out in Psittacanthus linearis (suelda con suelda), a representative species in the seasonally dry forest (SDF) from the north of Perú, was to study aspects of in vitro tissue culture, carry out preliminary phytochemical analysis, and assess antibacterial activity. Seeds of individuals of P. linearis, which used Prosopis pallida (algarrobo) as host plant, were collected and used to induce in vitro seed germination, clonal propagation, callus induction and organogenesis. Stems, leaves and fruits of individuals of P. linearis were dried, powdered, and subjected to ethanol extraction. Posteriorly the extract was first recovered with ethanol and the remnant with chloroform, which formed the ethanolic and chloroformic fraction. A preliminary phytochemical screening was performed and preliminary antibacterial studies with Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were carried out and their results are discussed. This is the first report about in vitro tissue culture, phytochemical analysis and antibacterial activity of P. linearis. The results may have important implications for understanding physiological and biochemical interactions between host and hemiparasitic species as well as P. linearis with P. pallida and other SDF species.

RESUMEN Las plantas hemiparásitas o 'mistletoe' o 'muérdago' son comunes en varios grupos vegetales o árboles, perteneciendo a las familias Santalaceae and Loranthaceae y muchas plantas hemiparásitas son usadas como medicina en varios lugares del mundo. El objetivo del presente trabajo realizado en Psittacanthus linearis or 'suelda con suelda', especie representativa en el bosque estacionalmente seco (BES) del norte del Perú, fue estudiar algunos aspectos en el cultivo de tejidos in vitro, el análisis fitoquímico preliminar y su actividad antibacterial. Semillas de P. linearis teniendo a Prosopis pallida 'algarrobo' como hospedero, fueron colectadas y utilizadas en la germinación in vitro, propagación clonal, inducción de callos y procesos organogénicos. Tallos, hojas y frutos de plantas silvestres fueron secados, pulverizados y sometidos a extracción con etanol y el extracto fue recuperado primero con etanol y el remanente con cloroformo formando las fraciones etanólica y clorofórmica. Se realizó un estudio fitoquímico y antibacteriano preliminar utilizando Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosa y los resultados son discutidos. Este trabajo es el primer estudio sobre cultivo de tejidos, análisis fitoquímico y actividad antibacteriana de P. linearis. Los resultados obtenidos tienen importantes implicancias para el conocimiento de las interacciones fisiológicas y bioquímicas entre las especies hospederas y las plantas hemiparásitas, como P. linearis con P. pallida y otras especies del BES.

Dinámica de polifenoles y estudio anatomo-histoquímico en Schinus longifolius (Lindl.) Speg. (Anacardiaceae) en respuesta a la infección por Calophya mammifex (Hemiptera – Calophyidae) / Dynamics of polyphenols and anatomical and histochemical study in Schinus longifolius (Lindl.) Speg. (Anacardiaceae) in response to infection by Calophya mammifex (Hemiptera - Calophyidae)

Total phenols, total tannins, proanthocyanidins, total flavonoids and total hydroxycinnamic acids of healthy leaves and galls of Schinus longifolius (Lindl.) Speg. (Anacardiaceae) infected by Calophya mammifex (Hemiptera - Calophyidae) were analized. The gall presents a qualitative and quantitative change in the polyphenols analysed, with a reduction of phenols, tannins, flavonoids and hydroxycinnamic acids and an increased content of proanthocyanidins, whose monomer yielded cyanidin after acid cleavage. An anatomical survey was performed and clusters of sclereids and an increased vascular development respect of the healthy leaf were found. An histochemical survey showed a differential expression of polyphenolic compounds in their tissues. C. mammifex could use the gall as a shelter against adverse weather conditions and predators, and also provide food with less potentially harmful compounds in the early stages of its development.

Se analizaron los fenoles totales, taninos totales, proantocianidinas, flavonoides totales y ácidos hidroxicinámicos totales de hojas sanas y agallas de Schinus longifolius (Lindl.) Speg. (Anacardiaceae) infectado por Calophya mammifex (Hemiptera - Calophyidae). La agalla presenta una variación cuali-cuantitativa de los polifenoles estudiados, con una disminución de los fenoles, taninos, flavonoides y ácidos hidroxicinámicos y un aumento en el contenido de proantocianidinas, cuyo monómero se transforma en cianidina luego del clivaje ácido. Se realizó además un análisis anatómico de la agalla donde se encontraron acúmulos de esclereidas y un mayor desarrollo vascular respecto de la hoja sana y un ensayo histoquímico que mostró una expresión diferencial de metabolitos polifenólicos en sus tejidos. C. mammifex utiliza la agalla como refugio contra las condiciones climáticas adversas y predadores y provee además de alimento con menos compuestos potencialmente perjudiciales en las etapas tempranas de su desarrollo.

The catechin flavonoid reduces proliferation and induces apoptosis of murine lymphoma cells LB02 through modulation of antiapoptotic proteins

Flavonoids are products of secondary metabolism of plants. They are present in herbs and trees and also act as natural chemopreventives and anticancer agents. Ligaria cuneifolia (Ruiz & Pav.) Tiegh., Loranthaceae, is a hemiparasite species that belongs to Argentine flora. Phytochemical studies have disclosed the presence of quercetin, catechin-4β-ol and pro-anthocyanidine as polyphenolic compounds in the active extracts. We previously demonstrated that ethyl acetate extract was capable of reducing cell proliferation and inducing apoptotic death of lymphoid tumor cells. The aim of the current study is to determine whether or not catechin, isolated from L. cuneifolia extracts can induce leukemia cell death and to determine its effect on the cytoplasmatic proteins that modulate cell survival. Our results show that catechin can reduce proliferation of murine lymphoma cell line LB02. The effect is mediated by apoptosis at concentrations upper to 100 µg/mL. Cell death is related to the loss of mitochondrial membrane potential (ΔΨm) and a down regulation of survivin and Bcl-2 together with the increase of pro-apoptotic protein Bax. In summary, the current study indicates that catechin present in the extract of L. cuneifolia is in part, responsible for the anti-proliferative activity of whole extracts by induction of ΔΨm disruption and modulation of the anti-apoptotic proteins over expressed in tumor cells. These results give new findings into the potential anticancer and chemopreventive activities of L. cuneifolia.

Dinámica de polifenoles de “Cedrón” (Aloysia citrodora Palau -Verbenaceae-) en relación al desarrollo foliar / Polyphenol dinamics on “cedrón” (Aloysia citrodora Palau -Verbenaceae-) according to leave development

Leaf infusions from Aloysia citrodora Palau –Verbenaceae-, known as “cedrón” were analyzed in order to establish the possible influence of their development on polyphenols profile. Chromatographic fingerprints of infusions from young and full expanded leaves were performed and total phenols, total tannins, total flavonoids and total hydroxycinnamic acids were quantified. Young leaves had significative higher total phenols, total flavonoids and total hydroxycinnamic acids concentrations than full expanded leaves. This research suggest that the analyzed parameter should be considered when elaborating products from “cedrón” leaves, as the variation in compound concentration may translate in different biological activities.

Se analizaron las infusiones realizadas a partir de las hojas de Aloysia citrodora Palau –Verbenaceae-, conocida vulgarmente como “cedrón”, con el objeto de establecer la influencia del grado de desarrollo foliar en el perfil de polifenoles. Se obtuvieron los perfiles cromatográficos y se cuantificaron los fenoles totales, taninos totales, flavonoides totales y ácidos hidroxicinámicos totales provenientes de los extractos acuosos de las hojas jóvenes y adultas. Se observaron diferencias cuali-cuantitativas en el perfil de polifenoles cuando se comparan las hojas jóvenes con las hojas adultas. En las hojas jóvenes, las concentraciones de fenoles totales, flavonoides totales y ácidos hidroxicinámicos totales resultaron ser significativamente superiores a las determinadas en las hojas adultas. Los estudios realizados sugieren que la variable aquí analizada debe ser considerada al momento de elaborar productos en base a hojas de cedrón, dado que las diferentes concentraciones detectadas podrían traducirse en diferentes actividades biológicas.