Induction of Monoterpenoid Oxindole Alkaloids Production and Related Biosynthetic Gene Expression in Response to Signaling Molecules in Hamelia patens Plant Cultures.

Hamelia patens (Rubiaceae), known as firebush, is a source of bioactive monoterpenoid oxindole alkaloids (MOAs) derived from monoterpenoid indole alkaloids (MIAs). With the aim of understanding the regulation of the biosynthesis of these specialized metabolites, micropropagated plants were elicited with jasmonic acid (JA) and salicylic acid (SA). The MOA production and MIA biosynthetic-related gene expression were evaluated over time. The production of MOAs was increased compared to the control up to 2-fold (41.3 mg g DW-1) at 72 h in JA-elicited plants and 2.5-fold (42.4 mg g DW-1) at 120 h in plants elicited with SA. The increment concurs with the increase in the expression levels of the genes HpaLAMT, HpaTDC, HpaSTR, HpaNPF2.9, HpaTHAS1, and HpaTHAS2. Interestingly, it was found that HpaSGD was downregulated in both treatments after 24 h but in the SA treatment at 120 h only was upregulated to 8-fold compared to the control. In this work, we present the results of MOA production in H. patens and discuss how JA and SA might be regulating the central biosynthetic steps that involve HpaSGD and HpaTHAS genes.

Cyclic Hexapeptide from Bouvardia ternifolia (Cav.) Schltdl. and Neuroprotective Effects of Root Extracts.

Bouvardia ternifolia (Cav.) Schltdl. is a shrub that belongs to the Rubiaceae family and is distributed throughout México; it has been used for its antioxidant, neuroprotective, and anti-inflammatory properties. This work aimed to evaluate the protective effects of B. ternifolia root extracts on the blood-brain barrier and the positive regulation of cytokines IL-1ß, IL-6, and TNF-α, and the characterization of compounds present in the dichloromethane (BtD) and hexane (BtH) extracts. Male ICR mice were orally administered with B. ternifolia extracts for 5 days before a single injection of LPS. Administration of BtH and BtD significantly decreased Evans blue leakage into brain tissue by 70% and 68%, respectively. Meloxicam (MX) decreased the concentration of IL-1ß by 39.6%; BtM by 53.9%; BtAq by 48.4%; BtD by 31.9%, and BtH by 37.7%. BtH was the only treatment that significantly decreased the concentration of IL-6 by 32.2%. The concentration of TNF-α declined with each of the treatments. The chemical composition of BtD and BtH was characterized by GC-MS, and the cyclic hexapeptide was identified by 13C, 1H NMR, and two-dimension techniques. In the BtD extract, seven compounds were found and in BtH 13 compounds were found. The methanolic (BtM) and aqueous (BtAq) extracts were not subjected to chemical analysis, because they did not show a significant difference in the BBB protection activity. Therefore, the results suggested that the extracts BtD and BtH protect the blood-brain barrier, maintaining stable its selective permeability, thereby preventing LPS from entering the brain tissue. Simultaneously, they modulate the production of IL-1ß, IL-6, and TNF-α. It is important to note that this research only evaluated the complete extracts.

Mixed elicitation with salicylic acid and hydrogen peroxide modulates the phenolic and iridoid pathways in Castilleja tenuiflora plants.

MAIN CONCLUSION: SA and H2O2, in single and mixed elicitation stimulate specialized metabolism and activate oxidative stress in C. tenuiflora plants. Single elicitation with salicylic acid (SA at 75 µM) and, hydrogen peroxide (at 150 µM), and mixed elicitation (75 µM SA + 150 µM H2O2) were evaluated on specialized metabolism in Castilleja tenuiflora Benth. plants. Total phenolic content (TPC), phenylalanine ammonia-lyase (PAL) activity, antioxidant enzymes and specialized metabolite profiles, as well as the expression levels of eight genes involved in phenolic (Cte-TyrDC, Cte-GOT2, Cte-ADD, Cte-AO3, Cte-PAL1, Cte-CHS1) and terpene pathways (Cte-DXS1 and Cte-G10H) and their correlation with major metabolite (verbascoside and aucubin) concentrations were investigated. TPC content (three-fold) and PAL activity (11.5-fold) increased with mixed elicitation, as well as catalase and peroxidase activity (11.3-fold and 10.8-fold, respectively), compared to single elicitation. Phenylethanoid accumulation was greatest under mixed elicitation, followed by SA and H2O2. Lignan accumulation was differential, depending on the plant part and the elicitor. Flavonoids only appeared after mixed elicitation. The high concentration of verbascoside under mixed elicitation was related to a high gene expression. Single elicitation induced iridoid accumulation in specific parts (H2O2 in aerial parts and SA in roots), whereas under mixed elicitation, it accumulated in both parts. A high concentration of aucubin in the aerial part was related to a high expression level of genes of the terpene pathway Cte-DXS1 and Cte-G10H, and in the root with Cte-G10H, while Cte-DXS1 was downregulated in this tissue in all treatments. Mixed elicitation with SA and H2O2 represents an interesting tool to increase the production of specialized metabolites in plants.

A Mixture of Kaempferol-3-O-sambubioside and Kaempferol-3-O-sophoroside from Malvaviscus arboreus Prevents Ethanol-Induced Gastric Inflammation, Oxidative Stress, and Histologic Changes.

Malvaviscus arboreus is used in traditional Mexican medicine to treat gastrointestinal diseases. Therefore, a mixture of Kaempferol-O-sambubioside and Kaempferol-O-sophoroside (MaSS) isolated from flowers of this species was tested as a preventive treatment on gastric lesions induced with ethanol in rats. MaSS was obtained by chromatographic methods and administered by oral pathway to male Sprague Dawley rats with ethanol-induced gastric lesions. Pretreatment with MaSS at doses of 30, 90, 120, and 180 mg/kg significantly prevents gastric lesions, inhibits the increment in relative stomach weight (%) in gastric IL-6, and also provokes an increment of IL-10 concentration and catalase activity. Finally, MaSS prevented edema in the mucosa and submucosa and diminished microscopic gastric lesions provoked by ethanol.

Do Intestinal Unicellular Parasites Have a Role in the Inflammatory and Redox Status among the Severely Obese?

The diagnosis of obesity comprises subjects with totally different phenotypes and metabolic profiles. Systemic inflammation and oxidative stress derived from the white adipose tissue are suggested as the link between this disease and the development of insulin resistance and metabolic comorbidities. The presence of unicellular eukaryotic parasites colonizing the human gut ecosystem is a common circumstance, and yet their influence on the inflammatory and redox status of the obese host has not been assessed. Herein, a set of inflammatory and redox biomarkers were assessed together with a parasitological analysis of 97 severely obese subjects. Information was also collected on insulin resistance and on the antioxidant composition of the diet. The global prevalence of intestinal unicellular parasites was 49.5%, with Blastocystis sp. the most prevalent protozoan found (42.3%). Colonized subjects displayed a higher total antioxidant capacity and a trend towards higher extracellular superoxide dismutase activity, regardless of their insulin resistance status, along with lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratios in plasma in the insulin-resistant subgroup. No changes in malondialdehyde levels, or in inflammatory cytokines in plasma, were found in regard to the colonization status. In conclusion, enteric eukaryotic unicellular parasites may play an important role in modulating the antioxidant defenses of an obese host, thus could have beneficial effects with respect to the development of systemic metabolic disorders.

Anti-arthritic and anti-inflammatory effects of Baccharis conferta Kunth in a kaolin/carrageenan-induced monoarthritis model.

ETHNOPHARMACOLOGICAL RELEVANCE: Popularly known as "escoba" (broom) or "escobilla china" (Chinese brush), Baccharis conferta Kunth (Asteraceae), is a plant widely used in Mexican folk medicine for alleviating muscular and rheumatic pain. A recent study described that dichloromethane extract as well as fractions and isolated compounds, possess anti-inflammatory activity in TPA-induced acute edema. AIM OF THE STUDY: Based on the popular medicinal uses of B. conferta as well as previous studies on its anti-inflammatory activity, the aim of this research was to evaluate the anti-arthritic and anti-inflammatory effects of dichloromethane extract, fractions, and compounds from B. conferta in a monoarthritis model induced with kaolin/carrageenan (K/C). MATERIALS AND METHODS: Aerial parts of B. conferta were collected, dried, and macerated with dichloromethane. The dichloromethane extract (BcD) was separated by open column chromatography to obtain the BcD2 fraction where the diterpene kingidiol (KIN) was isolated and from the BcD3 fraction the flavonoid cirsimaritin (CIR), which are the most active compounds in the TPA model. In addition, the flavonoids acacetin, pectolinaringenin and 6-methoxykaempferide were identified and isolated from the BcD2 fraction. The content of the main compounds was estimated in BcD, BcD2 and BcD3. The anti-arthritic and anti-inflammatory effects of B. conferta were investigated by evaluating ankle joint inflammation, hyperalgesia using the hot plate test, and pro- and anti-inflammatory cytokine levels in the synovial capsule as well as histological changes in ankle joint tissue in a monoarthritis model induced with K/C in Balb/c mice. RESULTS: Oral administration of BcD2 fraction (25 mg/kg) and KIN (10 mg/kg) reduced the ankle thickness induced by K/C and decreased the levels of TNF-α, IL-1ß, IL-6 and IL-17, while BcD2 increased IL-10. In addition, BcD2 and KIN showed significant edema attenuation of the synovial membrane and decreased inflammatory infiltration and cartilage erosion compared to the VEH group. Finally, BcD (50 mg/kg), KIN (10 mg/kg) and CIR (5 mg/kg) decreased hyperalgesia. CONCLUSIONS: B. conferta constitutes a therapeutic or preventive candidate for osteoarthritis, because of decreased articular inflammation and pain accompanied with the modulation of cytokine concentrations, which confirms the anti-arthritic and anti-inflammatory activities of B. conferta and support its popular use.

New Chromones from Bouvardia ternifolia (Cav.) Schltdl with Anti-Inflammatory and Immunomodulatory Activity.

The extract, fractions, and compounds of the Bouvardia ternifolia root were evaluated as an antiarthritic using a complete Freund's adjuvant (CFA) model in mice and NF-κB inhibition in RAW 264.7 macrophages. Four active compounds, including two new compounds, ternifoliol and ternifolial, were isolated by open column chromatography and identified by spectroscopic and spectrometric techniques, resulting in benzochromone-like structures with aromatic rings and hydroxyl groups, which could be responsible for the anti-inflammatory activity and inhibitory NF-κB. Changes in the joint cytokine profile monitored the antiarthritic effect. A decrement was observed in the local concentration of the following cytokines with different treatments: IL-17 by 64% and 70.3% with the aqueous extract (BtAq), ethyl acetate extract (BtAcOEt), and M3 fraction; interleukin-1 beta (IL-1ß) by 10.2% and 15.7% with BtAq and the M4 fraction, respectively; IL-6 with M1, M2, M3, and M4 between 42% and 64%; necrosis factor-alpha (TNF-α) by 60.9% with M4. Conversely, the anti-inflammatory cytokine interleukin-10 (IL-10) increased between 94% and 99% with M1, M2, M3, and M4. Kidney IL-6 decreased with BtAq, M1, M2, M3, and M4 between 68.9% and 85.8%. TNF-α decreased with BtAcOEt, BtAq, M1, M2, and M4 between 34% and 80.2%. The NF-κB pathway was inhibited with BtAcOEt (90.1%), M1 (85%), M2 (93.5%), M3 (84.5%), M4 (90.3%), ternifoliol (75.6%), bouvardin (20.4%), and scopoletin (89%). We conclude that B. ternifolia modulated the inflammatory response at the joint and kidney levels and the NF-κB pathway.

In Vitro Bile Salt Hydrolase (BSH) Activity Screening of Different Probiotic Microorganisms.

Bile salt hydrolase (BSH) activity in probiotic strains is usually correlated with the ability to lower serum cholesterol levels in hypercholesterolemic patients. The objective of this study was the evaluation of BSH in five probiotic strains of lactic acid bacteria (LAB) and a probiotic yeast. The activity was assessed using a qualitative direct plate test and a quantitative high-performance thin- layer chromatography assay. The six strains differed in their BSH substrate preference and activity. Lactobacillus plantarum DGIA1, a potentially probiotic strain isolated from a double cream cheese from Chiapas, Mexico, showed excellent deconjugation activities in the four tested bile acids (69, 100, 81, and 92% for sodium glycocholate, glycodeoxycholate, taurocholate, and taurodeoxycholate, respectively). In the case of the commercial probiotic yeast Saccharomyces boulardii, the deconjugation activities were good against sodium glycodeoxycholate, taurocholate, and taurodeoxycholate (100, 57, and 63%, respectively). These last two results are part of the novelty of the work. A weak deconjugative activity (5%) was observed in the case of sodium glycocholate. This is the first time that the BSH activity has been detected in this yeast.

Synergism and Subadditivity of Verbascoside-Lignans and -Iridoids Binary Mixtures Isolated from Castilleja tenuiflora Benth. on NF-κB/AP-1 Inhibition Activity.

Pharmacodynamic interactions between plant isolated compounds are important to understand the mode of action of an herbal extract to formulate or create better standardized extracts, phytomedicines, or phytopharmaceuticals. In this work, we propose binary mixtures using a leader compound to found pharmacodynamic interactions in inhibition of the NF-κB/AP-1 pathway using RAW-Blue™ cells. Eight compounds were isolated from Castilleja tenuiflora, four were new furofuran-type lignans for the species magnolin, eudesmin, sesamin, and kobusin. Magnolin (60.97%) was the most effective lignan inhibiting the NF-κB/AP-1 pathway, followed by eudesmin (56.82%), tenuifloroside (52.91%), sesamin (52.63%), and kobusin (45.45%). Verbascoside, a major compound contained in wild C. tenuiflora showed an inhibitory effect on NF-κB/AP-1. This polyphenol was chosen as a leader compound for binary mixtures. Verbacoside-aucubin and verbascoside-kobusin produced synergism, while verbascoside-tenuifloroside had subadditivity in all concentrations. Verbascoside-kobusin is a promising mixture to use on NF-κB/AP-1 related diseases and anti-inflammatory C. tenuiflora-based phytomedicines.

Angiotensin-converting enzyme inhibitors from Salvia elegans Vahl.

Phytochemical research of the acetate and methanol extracts of the aerial parts (flowers, leaves and stems) of Salvia elegans allowed to obtain seventeen known compounds (1-17): three of them (4, 5, 14), had already been described for this species, while the others (1-3, 6-13, 15-17) are described for the first time for S. elegans. All isolated compounds were characterized using spectroscopic techniques and mass spectrometry and were evaluated in the Angiotensin I-converting enzyme (ACE) inhibition model, where the phenolic compounds (13, 14 and 15) had the same inhibitory effect as lisinopril at 0.02 mg/mL. The terpenes showed a moderate inhibitory capacity at a concentration of 0.2 mg/mL.

Gastroprotective activity of kaempferol glycosides from Malvaviscus arboreus Cav.

ETHNOPHARMACOLOGICAL RELEVANCE: Malvaviscus arboreus is traditionally used in Mexico and Central America for culinary and medicinal purposes. Leaves and flowers of this species are commonly used for preparation of salads, herbal teas and herbal dyes. Panamanian, Guatemalan and Mexican healers use this medicinal plant for the management of fever, respiratory complications, dysentery, liver and gallbladder problems, stomachache and gastritis between other health troubles. AIM OF THE STUDY: Considering the traditional use of M. arboreous as well as its content in flavonoids and other polyphenols, the objective of this work was to evaluate the gastroprotective effect of an aqueous extract and identify the potential bio-active principles from flowers of this species. MATERIAL AND METHODS: Fresh flowers of Malvaviscus arboreus were collected, dried, and macerated with water. The aqueous extract (ExAq) was partitioned using an immiscible mixture of water and ethyl acetate, giving an aqueous (MaAq) and organic (MaEA) fractions. The gastroprotective effect was carried out using an ethanol-induced gastric ulcer experimental test in male rats. While tween 20 was used as a negative control, famotidine (10 mg/kg) and L-arginine (300 mg/kg) were used as positive controls. Compounds 1 and 2 were isolated by several chromatographic techniques and the chemical characterization was carried out by means of the analysis of the NMR spectra in one and two dimensions. RESULTS: The integrate extract (ExAq) to 250, 500 and 750 mg/kg showed gastroprotective effect with high levels of 97.8%, 79.5% and 91.1% respectively. The organic fraction (MaEA) displayed a protection of 91.2%, 96.0% and 99.4% when it was evaluated at 125, 250 and 500 mg/kg respectively. Comparison of these results with famotidine at 10 mg/kg (83% of gastroprotection) indicated that ethyl acetate fraction showed a better gastroprotection. The bio-guided separation of this organic mixture, allowed obtaining the most active fraction (C1F4, 60 mg/kg) which was finally purified to obtain two glycosylated flavonols: kaempferol 3-O-D-sophoroside (1) and kaempferol 3-O-D-sambubioside (2). This mixture of flavonoids (40 y 60 mg/kg) showed 93.7 and 92% of gastroprotective activity respectively. CONCLUSION: This study allowed demonstrating that an aqueous extract and its organic fraction (MaEA) from M. arboreous contain glycosylated flavonoids (1 and 2) which are responsible of the gastroprotective properties of M. arboreous. These results will be used in the future development of a standardized treatment useful in the therapeutic management of gastric ulcers.

Primary cilium remodeling mediates a cell signaling switch in differentiating neurons.

Cellular differentiation leads to the formation of specialized cell types and complex morphological variations. Often, differentiating cells transition between states by switching how they respond to the signaling environment. However, the mechanisms regulating these transitions are poorly understood. Differentiating neurons delaminate from the neuroepithelium through the regulated process of apical abscission, which mediates an acute loss of polarity and primary cilium disassembly. Using high-resolution live-cell imaging in chick neural tube, we show that these cells retain an Arl13b+ particle, which elongates and initiates intraflagellar trafficking as it transits toward the cell body, indicating primary cilium remodeling. Notably, disrupting cilia during and after remodeling inhibits axon extension and leads to axon collapse, respectively. Furthermore, cilium remodeling corresponds to a switch from a canonical to noncanonical cellular response to Shh. This work transforms our understanding of how cells can rapidly reinterpret signals to produce qualitatively different responses within the same tissue context.

Discovery of a Gatekeeper Residue in the C-Terminal Tail of the Extracellular Signal-Regulated Protein Kinase 5 (ERK5).

The extracellular signal-regulated protein kinase 5 (ERK5) is a non-redundant mitogen-activated protein kinase (MAPK) that exhibits a unique C-terminal extension which comprises distinct structural and functional properties. Here, we sought to elucidate the significance of phosphoacceptor sites in the C-terminal transactivation domain of ERK5. We have found that Thr732 acted as a functional gatekeeper residue controlling C-terminal-mediated nuclear translocation and transcriptional enhancement. Consistently, using a non-bias quantitative mass spectrometry approach, we demonstrated that phosphorylation at Thr732 conferred selectivity for binding interactions of ERK5 with proteins related to chromatin and RNA biology, whereas a number of metabolic regulators were associated with full-length wild type ERK5. Additionally, our proteomic analysis revealed that phosphorylation of the Ser730-Glu-Thr732-Pro motif could occur independently of dual phosphorylation at Thr218-Glu-Tyr220 in the activation loop. Collectively, our results firmly establish the significance of C-terminal phosphorylation in regulating ERK5 function. The post-translational modification of ERK5 on its C-terminal tail might be of particular relevance in cancer cells where ERK5 has be found to be hyperphosphoryated.

Queratoacantoma tratado con metotrexato intralesional: una alternativa terapéutica efectiva en casos seleccionados / Keratoacanthoma treated with intralesional methotrexate: an effective therapeutic alternative in selected cases

El Queratoacantoma es un carcinoma de células escamosas de rápido crecimiento, cuyo tratamiento definitivo contempla la resección quirúrgica. El manejo se dificulta cuando las condiciones de la lesión implican cirugías extensas o las condiciones del paciente son riesgosas al plantear manejo invasivo. Se propone el uso de Metotrexato intralesional como estrategia terapéutica alternativa al tratamiento quirúrgico tradicional. Se exponen 2 casos en los cuales se usó este método. Primero es una paciente de 91 años con queratoacantoma en región frontal, de rápido crecimiento. Segundo, un paciente de 76 años, en tratamiento anticoagulante, con lesión en cuero cabelludo. Ambos pacientes reciben inyecciones de Metotrexato, las cuales muestran resultados significativos, en cuanto a reducción de tamaño. La inyección intralesional de Metotrexato demuestra utilidad como alternativa terapéutica o como manejo neoadyuvante previo a la cirugía

Keratoacanthoma is a rapidly growing squamous cell carcinoma, which definitive treatment includes surgical resection. Therapy becomes more complex when the lesion requires extensive surgeries or the patient's conditions are risky for invasive management. The use of intralesional methotrexate is proposed as an alternative therapeutic strategy to traditional surgical treatment. Two cases are presented where this method was used. First a 91-year-old patient with rapidly growing keratoacanthoma in the frontal region. Second a 76-year-old patient, undergoing anticoagulant treatment, with a scalp lesion. Methotrexate injections were applied to both patients, with significant lesion size reduction. Intralesional injection of Methotrexate proves useful as a therapeutic alternative or as neoadjuvant management prior to surgery.

Improving the production of podophyllotoxin in hairy roots of Hyptis suaveolens induced from regenerated plantlets.

Ten Hyptis suaveolens hairy root lines were established by infecting nodal explants with K599+pGus-GFP+ and ATCC15834+pTDT strains from Agrobacterium rhizogenes. Genetic transformation was confirmed by epifluorescence and plagiotropic hairy root growth in absence of growth regulators. Cytotoxicity was determined using the sulforhodamine B method, and the production of podophyllotoxin (PTOX) was measured by high performance thin layer chromatography scanning. Through these methodologies, HsTD10 was identified as the hairy root line with the highest cytotoxicity and PTOX production, which was corroborated by liquid chromatography-mass spectrometry and micrOTOF-Q II. A suspension culture of HsTD10 was established in which PTOX and carbohydrate consumption during growth kinetics were quantified by high-performance liquid chromatography. Procedures to increase the production and retrieval of PTOX in the HsTD10 line included selection of culture medium, addition of thiamine, and modification of the PTOX extraction method. The best combination of these variables was MS medium at 75% of its components with the addition of 2 mg L-1 of thiamine, extraction with methanol-dichloromethane, and sonication at 40 ± 5°C. During kinetics, growth-associated PTOX accumulation was observed. The specific growth rate (µ) was 0.11 d-1. The highest concentration of PTOX obtained with HsTD10 (5.6 mg g-1 DW) was 100 times higher than that reported for roots of wild plants and 56 times higher than that for in vitro nontransformed roots of H. suaveolens.

Glucoindole alkaloid accumulation induced by yeast extract in Uncaria tomentosa root cultures is involved in defense response.

OBJECTIVE: To evaluate the induction of monoterpenoid indole alkaloids (MIA) and phenolic compound production by yeast extract (YE) and its relationship with defense responses in Uncaria tomentosa (Rubiaceae) root cultures. RESULTS: Root cultures were elicited by YE at three concentrations. The 0.5 mg YE ml-1 treatment did not affect cell viability but increased the hydrogen peroxide concentration by 5.7 times; guaiacol peroxidase activity by twofold; and the glucoindole alkaloid 3α-dihydrocadambine (DHC) content by 2.6 times (to 825.3 ± 27.3 µg g-1). This treatment did not affect the contents of monoterpenoid oxindole alkaloids or chlorogenic acids. In response to 0.5 mg YE ml-1 treatment, the transcript levels of MIA biosynthetic genes, TDC and LAMT, increased 5.4 and 1.9-fold, respectively, that of SGD decreased by 32%, and that of STR did not change. The transcript levels of genes related to phenolic compounds, PAL, CHS and HQT, increased by 1.7, 7.7, and 1.2-fold, respectively. Notably, the transcript levels of Prx1 and Prx encoding class III peroxidases increased by 1.4 and 2.5-fold. CONCLUSION: The YE elicitor induced an antioxidant defense response, increased the transcript levels of genes encoding enzymes related to strictosidine biosynthesis precursors and class III peroxidases, and decreased the transcript level of SGD. Thus, YE could stimulate antifungal DHC production in root cultures of U. tomentosa.

In Vivo Gastroprotective and Antidepressant Effects of Iridoids, Verbascoside and Tenuifloroside from Castilleja tenuiflora Benth.

Stress is an important factor in the etiology of some illnesses such as gastric ulcers and depression. Castilleja tenuiflora Benth. (Orobanchaceae) is used in Mexican traditional medicine for the treatment of gastrointestinal diseases and nervous disorders. Previous studies indicated that organic extracts from C. tenuiflora had gastroprotective effects and antidepressant activity. In this study, we aimed to evaluate the gastroprotective and antidepressant activity of fractions and isolated compounds from the methanolic extract (MECt) of C. tenuiflora in stressed mice. Chromatographic fractionation of MECt produced four fractions (FCt-1, FCt-2, CFt-3, and FCt-4) as well as four bioactive compounds which were identified using TLC, HPLC and NMR analyses. The cold restraint stress (CRS)-induced gastric ulcer model followed by the tail suspension test and the forced swim test were used to evaluate the gastroprotective effect and antidepressant activity of the extract fractions. FCt-2 and FCt-3 at 100 mg/kg had significant gastroprotective and antidepressant effects. All isolated compounds (verbascoside, teniufloroside and mixture geniposide/ musseanoside) displayed gastroprotective effects and antidepressant activity at 1 or 2 mg/kg. The above results allow us to conclude that these polyphenols and iridoids from C. tenuiflora are responsible for the gastroprotective and antidepressant effects.

Influence of spermine and nitrogen deficiency on growth and secondary metabolites accumulation in Castilleja tenuiflora Benth. cultured in a RITA® temporary immersion system.

The effect of exogenous spermine (SPM) on Castilleja tenuiflora shoots developing under nitrogen deficiency (ND) stress was evaluated. Shoots cultivated in a temporary immersion system were subjected to four experimental treatments: (1) control; (2) exogenous SPM; (3) ND; and (4) ND+SPM. Shoots were longer in the ND+SPM treatment (6.3 ± 0.5 cm) than in the ND treatment (4.2 ± 0.5 cm). The total chlorophyll content was similar in the control and SPM treatments (0.41 µg mg-1 FM) and the highest values of total phenolic content were detected at 21 days in the ND+SPM treatment (84.1 ± 0.05 GAE g-1 DM). In the ND+SPM treatment, the phenylalanine ammonia lyase activity increased earlier than in ND treatment, and reached its maximum at day 21 (3.9 ± 0.2 µmol E-CIN h-1 mg-1 protein). Compared with the control, the ND and ND+SPM treatments resulted in increased secondary metabolites contents in both root and aerial parts. The strongest effect was in the roots, where the SPM and ND+SPM treatments both resulted in increased quercetin content (4.3-fold that in the control). Our results showed that SPM partially counteract the damage caused by ND and results in increased contents of valuable bioactive compounds.

The Ric-8A/Gα13/FAK signalling cascade controls focal adhesion formation during neural crest cell migration in Xenopus.

Ric-8A is a pleiotropic guanine nucleotide exchange factor involved in the activation of various heterotrimeric G-protein pathways during adulthood and early development. Here, we sought to determine the downstream effectors of Ric-8A during the migration of the vertebrate cranial neural crest (NC) cells. We show that the Gα13 knockdown phenocopies the Ric-8A morphant condition, causing actin cytoskeleton alteration, protrusion instability, and a strong reduction in the number and dynamics of focal adhesions. In addition, the overexpression of Gα13 is sufficient to rescue Ric-8A-depleted cells. Ric-8A and Gα13 physically interact and colocalize in protrusions of the cells leading edge. The focal adhesion kinase FAK colocalizes and interacts with the endogenous Gα13, and a constitutively active form of Src efficiently rescues the Gα13 morphant phenotype in NC cells. We propose that Ric-8A-mediated Gα13 signalling is required for proper cranial NC cell migration by regulating focal adhesion dynamics and protrusion formation.

Ric-8A, a GEF for heterotrimeric G-proteins, controls cranial neural crest cell polarity during migration.

The neural crest (NC) is a transient embryonic cell population that migrates extensively during development. Ric-8A, a guanine nucleotide exchange factor (GEF) for different Gα subunits regulates cranial NC (CNC) cell migration in Xenopus through a mechanism that still remains to be elucidated. To properly migrate, CNC cells establish an axis of polarization and undergo morphological changes to generate protrusions at the leading edge and retraction of the cell rear. Here, we aim to study the role of Ric-8A in cell polarity during CNC cell migration by examining whether its signaling affects the localization of GTPase activity in Xenopus CNC using GTPase-based probes in live cells and aPKC and Par3 as polarity markers. We show that the levels of Ric-8A are critical during migration and affect the localization of polarity markers and the subcellular localization of GTPase activity, suggesting that Ric-8A, probably through heterotrimeric G-protein signaling, regulates cell polarity during CNC migration.