RESUMO
Acmella radicans (Asteraceae) is a plant native to America. Despite it having medicinal attributes, studies on its phytochemical properties are scarce, and biotechnological studies do not exist for this species. In this study, we established an adventitious root culture from A. radicans internodal segments in shake flasks with indole-3-butyric acid (IBA), and then elicited it with jasmonic acid (JA) and salicylic acid (SA). The total phenolic content and antioxidant activity were evaluated, and a comparison was made using in vitro plantlets and wild plants. Internodal segments with 0.1 mg/L IBA showed 100% root induction and exhibited better growth after transfer to shake flasks with MS liquid culture medium. JA had a significant effect on biomass increase compared to unelicited roots, mainly with 50 µM JA (28%), while SA did not show significant results. Root elicited with 100 µM (SA and JA) showed a 0.34- and 3.9-fold increase, respectively, in total phenolic content (TPC) compared to the control. The antioxidant activity was also significant, and a lower half-maximal inhibitory concentration (IC50) was observed as the AJ concentration increased. Roots elicited with AJ (100 µM) exhibited high antioxidant activity with DPPH (IC50 = 9.4 µg/mL) and ABTS (IC50 = 3.3 µg/mL) assays; these values were close to those for vitamin C (IC50 = 2.0 µg/mL). The TPC and antioxidant activity of in vitro plants and root cultured in shake flasks showed the lowest values in most cases; even the root cultures without elicitation were better than those of a wild plant. In this study, we demonstrated that A. radicans root culture is capable of producing secondary metabolites, while its production and antioxidant activity can be enhanced using jasmonic acid.
Assuntos
Antioxidantes , Asteraceae , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Biomassa , Ácido Salicílico/farmacologiaRESUMO
In vitro growth of hematopoietic cells depends on the presence of hematopoietic cytokines. To date, it is unclear if these cells would be able to respond to non-hematopoietic cytokines. In the present study, we have explored this by culturing human hematopoietic cells in presence of neurogenic cytokines. Lineage-negative (Lin-) umbilical cord blood (UCB)-derived cells -enriched for hematopoietic stem and progenitor cells- were cultured in presence of different combinations of hematopoietic cytokines, neurotrophins, epidermal growth factor, fibroblast growth factor, and neurogenic culture media, in a 3-phase culture system. A proportion (1-22%) of Lin- UCB hematopoietic cells normally express neural markers and are capable of responding to neural cytokines. Neural cytokines did not have effects on hematopoietic cell proliferation; however, we observed generation of neural-like cells, assessed by morphology, and a significant increase in the proportion of cells expressing neural markers. Such neural-like cells, however, retained expression of hematopoietic markers. It seems that under our culture conditions, no actual transdifferentiation of hematopoietic cells into neural cells occurred; instead, the cells generated in culture seem to be hematopoietic cells that acquired neural features upon contact with neurogenic factors. The identity of UCB cells that acquired a neural phenotype is still unclear.
Assuntos
Sangue Fetal/citologia , Células-Tronco Hematopoéticas/citologia , Neurogênese , Técnicas de Cultura de Células , Células Cultivadas , Citocinas/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Fatores de Crescimento Neural/metabolismo , Neurônios/citologia , Neurônios/metabolismoRESUMO
The screening and testing of extracts against a variety of pharmacological targets in order to benefit from the immense natural chemical diversity is a concern in many laboratories worldwide. And several successes have been recorded in finding new actives in natural products, some of which have become new drugs or new sources of inspiration for drugs. But in view of the vast amount of research on the subject, it is surprising that not more drug candidates were found. In our view, it is fundamental to reflect upon the approaches of such drug discovery programs and the technical processes that are used, along with their inherent difficulties and biases. Based on an extensive survey of recent publications, we discuss the origin and the variety of natural chemical diversity as well as the strategies to having the potential to embrace this diversity. It seemed to us that some of the difficulties of the area could be related with the technical approaches that are used, so the present review begins with synthetizing some of the more used discovery strategies, exemplifying some key points, in order to address some of their limitations. It appears that one of the challenges of natural product-based drug discovery programs should be an easier access to renewable sources of plant-derived products. Maximizing the use of the data together with the exploration of chemical diversity while working on reasonable supply of natural product-based entities could be a way to answer this challenge. We suggested alternative ways to access and explore part of this chemical diversity with in vitro cultures. We also reinforced how important it was organizing and making available this worldwide knowledge in an "inventory" of natural products and their sources. And finally, we focused on strategies based on synthetic biology and syntheses that allow reaching industrial scale supply. Approaches based on the opportunities lying in untapped natural plant chemical diversity are also considered.
RESUMO
Lychnis flos-cuculi L., Caryophyllaceae, contains a number of active compounds belonging to several chemical groups. Previous studies have led to the identification of phytoecdysteroids, triterpenoids saponins, volatile compounds, fatty acid derivatives, phenolic acids and flavonoids. Research on pharmacological activity showed that plant extracts inhibited the growth of bacteria and fungi. The antimitotic properties of preparations from the herb L. flos-cuculi were also reported. The phytochemical analyses demonstrated that this taxon contains pharmaceutically promising compounds, but more phytochemical and pharmacological studies of L. flos-cuculi are needed for further information regarding this plant. This review summarizes reports regarding chemical composition and biological activity of L. flos-cuculi as well as several cognate species, which pose opportunities related to in vitro propagation and cell and tissue cultures. In vitro-regenerated plantlets could be a good source of genetically uniform plant material for future research.
RESUMO
Nicotiana tabacum hairy roots that express the antibody 14D9 were established. The 14D9 antibody yield obtained after 20 days of culture was 5.95 μg 14D9ml-1. The addition of the reticulum endoplasmic retention sequence KDEL demonstrated a positive effect over the intracellular 14D9 amounts with a yield increase up to 20.82 µg ml-1. DMSO increased the antibody amount in the biomass from 20.00 to 64.03 µg ml-1 while PVP (at 1.5 gl-1) and gelatine (at 5.0 gl-1) increased total 14D9 amounts in the culture medium to 25 µg and 14 µg respectively.