RESUMEN
Silene is a genus of the Caryophyllaceae family, contains more than 700 species, which are widely distributed in Northern Hemisphere, but also in Africa, Asia and South American. Phytochemical investigations of Silene species have revealed that many components from this genus are highly bioactive. More than 400 compounds has been isolated, among them major are phytoecdysteroids. The paper reviews the biological (antitumour, antibacterial and antioxidant) activities and the phytoecdysteroids of genus Silene. We summarized the phytoecdysteroids content referring to 171 species from the genus Silene and list 93 phytoecdysteroids isolated over the past few decades. There are also reports on the mentioned folk and traditional effects of Silene plants.
Silene es un género de la familia Caryophyllaceae, conteniendo más de 70 especies, ampliamente distribuidas no solo en el hemisferio norte, sino que también en Africa, Asia y sud América. Investigaciones fotoquímicas de las especies de Silene han revelado que muchos componentes de este género son altamente bioactivos. Más de 400 compuestos han sido aislados, entre ellos los mayoritarios correspondientes a fitoecdiesteroides. El manuscrito revisa las actividades biológicas (antitumorales, antibacterianas y antioxidantes) y los fitoecdiesteroides del género Silene. Resumimos el contenido de fitoecdiesteroides en 171 especies del género Silene y listamos 93 fitoecdiesteroides aislados desde hace unas pocas décadas. Hay también reportes mencionados acerca de los efectos tradicionales y folclóricos de la plantas del género Silene.
Asunto(s)
Antibacterianos , Antineoplásicos Fitogénicos , Antioxidantes , Ecdisteroides , Plantas Medicinales/clasificación , Silene , Etnofarmacología , Medicina Tradicional , Especificidad de la EspecieRESUMEN
The cytotoxicological responses to insect growth regulator (IGR), using tebufenozide as ecdysteroid mimic, were investigated in Drosophila Kc cells. Treatment of Kc cells with tebufenozide showed significant growth inhibition and striking morphological changes including aggregation and elongation of the cells. In order to understand the cellular mechanism underlying the response of Drosophila cells to tebufenozide, immunofluorescence microscopy was performed. We found that treatment of Kc cells with tebufenozide enhanced the reorganization of f-actin and stimulated the expression of hsp27. These data suggest a possible association of filamentous actin (f-actin) and hsp27 in the cytotoxicological mechanisms of growth regulators in Drosophila cells.
Asunto(s)
Actinas , Drosophila , Ecdisteroides , Insectos , Microscopía Fluorescente , Huelga de EmpleadosRESUMEN
The effect of two insect growth regulators of plant origin viz. plumbagin and azadirachtin and the ecdysteroids 20-hydroxyecdysone, makisterone A and a phytoecdysteroid on DNA synthesis in imaginal wing discs of day 4 final instar Helicoverpa armigera larvae was studied. DNA synthesis increased with increase in time of incubation up to 8 h and decreased later without the addition of moulting hormone. Addition of 20-hydroxyecdysone supported long term acquisition of competence for DNA synthesis in the wing discs. Both DNA synthesis and protein content were drastically reduced in plumbagin and azadirachtin-treated insects. Under in vitro conditions, plumbagin had a more pronounced inhibitory effect than azadirachtin. All the ecdysteroids tested, viz. makisterone A, 20-hydroxyecdysone and the ecdysteroidal fraction from the silver fern Cheilanthes farinosa enhanced DNA synthesis.
Asunto(s)
Animales , ADN/biosíntesis , Ecdisona/análogos & derivados , Ecdisteroides/farmacología , Ecdisterona/farmacología , Proteínas de Insectos/metabolismo , Insecticidas/farmacología , Larva/fisiología , Limoninas , Mariposas Nocturnas/efectos de los fármacos , Naftoquinonas/farmacología , Triterpenos/farmacología , /anatomía & histologíaRESUMEN
We have analysed the evolution of ERG28/C14orf1, a gene coding for a protein involved in sterol biosynthesis. While primary sequence of the protein is well conserved in all organisms able to synthesize sterols de novo, strong divergence is noticed in insects, which are cholesterol auxotrophs. In spite of this virtual acceleration, our analysis suggests that the insect orthologues are evolving today at rates similar to those of the remaining members of the family. A plausible way to explain this acceleration and subsequent stabilization is that Erg28 plays a role in at least two different pathways. Discontinuation of the cholesterogenesis pathway in insects allowed the protein to evolve as much as the function in the other pathway was not compromised.
Asunto(s)
Animales , Arabidopsis/genética , Bombyx/genética , Caenorhabditis elegans/genética , Drosophila melanogaster/genética , Ecdisteroides/genética , Evolución Molecular , Humanos , Proteínas de Insectos , Intrones , Funciones de Verosimilitud , Proteínas de la Membrana/genética , Ratones , Proteínas de Neoplasias , Filogenia , Plantas/genética , Proteínas/genética , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Análisis de Secuencia de ADN , Homología de Secuencia , Programas InformáticosRESUMEN
Proallatotoxins, and particularly preconcenes, are exceptionally promising models for studying Rhodnius prolixus physiology and for comparison with other natural compounds with anti-hormonal activities. Effects of preconcenes on feeding, development and reproduction of R. prolixus are being detailed. The precocenes reveal significant effects on feeding, moulting cycle (inducing precocious metamorphosis and ecdysial stasis), and reproduction of these insect. The mechanism of action of proallatotoxins was discussed based on the corpus allatum cytotoxic effect and on the ecdysteroid biosynthesis in prothoracic glands and ovaries. Further studies of these compounds on R. prolixus are need and will hopefully reveal other unesplored points regarding the action of the proallatotoxins on insects.
Asunto(s)
Animales , Benzopiranos/farmacología , Ecdisteroides/uso terapéutico , Insecticidas/farmacología , Hormonas de Invertebrados/biosíntesis , Hormonas Juveniles/antagonistas & inhibidores , Larva/crecimiento & desarrolloRESUMEN
Extirpation of endocrine organs - a classic maneuver in hormonal research - has been difficult or impossible in the case of the prothoracic glands (PG) of insects. In larval and pupal Lepidoptera the glands are virtually inaccessible unless one sacrifices the insect. Even then, the PG are not easy to remove in their entirety. Consequently, in order to obtain viable preparations lacking PG, one costomarily makes use of abdomens isolated by litigation or surgery.