Identification and HPLC Quantification of a Phytoecdysone and Three Phenolic Glycosides in Lamium takesimense Nakai

The herbs of Lamium takesimense Nakai (Lamiaceae) is used to treat spasmodic and inflammatory disease. The four polar compounds, ecdysterone, isoacteoside, rutin and lamiuside C, were isolated and identified from the BuOH fraction of the L. takesimense MeOH extract. HPLC quantification was performed on a Capcell Pak C18 column (5 µm, 4.6 mm × 250 mm) with a gradient elution of H₂O and 0.05% acetic acid in MeOH. The HPLC method was validated in terms of linearity, sensitivity, stability, precision, and accuracy. The quantitative level in plant material was determined as the following order: lamiuside C (4, 3.75 mg/g dry weight) > ecdysterone (1, 1.93 mg/g) > isoacteoside (2, 1.32 mg/g) > rutin (3, 0.97 mg/g).

Anti-proliferative Activity of T-bet

T-bet is a critical transcription factor that regulates differentiation of Th1 cells from CD4+ precursor cells. Since T-bet directly binds to the promoter of the IFN-gamma gene and activates its transcription, T-bet deficiency impairs IFN-gamma production in Th1 cells. Interestingly, T-bet-deficient Th cells also display substantially augmented the production of IL-2, a T cell growth factor. Exogenous expression of T-bet in T-bet deficient Th cells rescued the IFN-gamma production and suppressed IL-2 expression. IFN-gamma and IL-2 reciprocally regulate Th cell proliferation following TCR stimulation. Therefore, we examined the effect of T-bet on Th cell proliferation and found that T-bet deficiency significantly enhanced Th cell proliferation under non-skewing, Th1-skewing, and Th2-skewing conditions. By using IFN-gamma-null mice to eliminate the anti-proliferative effect of IFN-gamma, T-bet deficiency still enhanced Th cell proliferation under both Th1- and Th2-skewing conditions. Since the anti-proliferative activity of T-bet may be influenced by IL-2 suppression in Th cells, we examined whether T-bet modulates IL-2-independent cell proliferation in a non-T cell population. We demonstrated that T-bet expression induced by ecdysone treatment in human embryonic kidney (HEK) cells increased IFN-gamma promoter activity in a dose dependent manner, and sustained T-bet expression considerably decreased cell proliferation in HEK cells. Although the molecular mechanisms underlying anti-proliferative activity of T-bet remain to be elucidated, T-bet may directly suppress cell proliferation in an IFN-gamma- or an IL-2-independent manner.

Effect of blood components, abdominal distension, and ecdysone therapy on the ultrastructural organization of posterior midgut epithelial cells and perimicrovillar membranes in Rhodnius prolixus

The effects of blood components, nerve-cord severance, and ecdysone therapy on the posterior midgut epithelial cells of 5th-instar Rhodnius prolixus nymphs 10 days after feeding were analyzed by transmission electron microscopy. Cutting the nerve-cord of the blood-fed insects partially reduced the development of microvilli and perimicrovillar membranes (PMM), and produced large vacuoles and small electrondense granules; insects fed on Ringer's saline diet exhibited well developed microvilli and low PMM production; swolled rough endoplasmatic reticulum and electrondense granules; Ringer's saline meal with ecdysone led to PMM development, glycogen particles, and several mitochondria in the cytoplasm; epithelial cells of the insects fed on Ringer's saline meal whose nerve-cord was severed showed heterogeneously distributed microvilli with reduced PMM production and a great quantity of mitochondria and glycogen in the cytoplasm; well developed microvilli and PMM were observed in nerve-cord severed insects fed on Ringer's saline meal with ecdysone; Ringer's saline diet containing hemoglobin recovered the release of PMM; and insects fed on human plasma showed slightly reduced PMM production, although the addition of ecdysone in the plasma led to a normal midgut ultrastructural organization. We suggest that the full development of microvilli and PMM in the epithelial cells depends on the abdominal distension in addition to ingestion of hemoglobin, and the release of ecdysone.

Chemical constituents of Cyanotis arachnoidea / 药学学报

<p><b>AIM</b>To investigate the chemical constituents of Cyanotis arachnoidea.</p><p><b>METHODS</b>By using chromatographic methods for separation and combination with spectral analysis, their chemical structures were determined.</p><p><b>RESULTS</b>Six compounds were identified as ajugasterone C-20, 22-acetonide (1), 20-hydroxyecdysone-20, 22-acetonide (2), 22-oxo-ajugasterone C (3), 22-oxo-20-hydroxyecdysone (4), beta-sitosterol (5), daucosterol (6).</p><p><b>CONCLUSION</b>Compound 3 is a new compound, 4 was a new natural compound.</p>

DNA synthesis in the imaginal wing discs of the American bollworm Helicoverpa armigera (Hübner).

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.

RH-5992--an ecdysone agonist on model system of the silkworm Bombyx mori.

RH-5992 is a novel synthetic non-steroidal ecdysteroid agonist with a high selectivity towards Lepidopteran species. The effect of ecdysone agonist RH-5992 on larval period, larval weight, silk gland weight and haemolymph protein profile were examined in the model organism, the larvae of silkworm, Bombyx mori. The LD50 values were found to be 16.21 and 12.01 micrograms/larva for 72 and 96 hr respectively. In the present study, three sublethal concentrations of 1/5th, 1/10th and 1/20th of LD50 at 72 hr were selected and applied on the mid-dorsal line of the silkworm B. mori. The maximum mortality of 35% was observed in the group which received the highest (3.2 micrograms/larva) concentration of RH-5992. The mortality rate was found to be dose dependent as well as time dependent. Interesting results were observed in haemolymph profile of the RH-5992 treated larvae as staining intensity of 30 kDa protein decreased significantly whereas the effect was not marked on other major proteins like storage proteins and vitellogenin polypeptides. From the results, it is confirmed that RH-5992 causes changes in larval characters and protein profile of silkworm B. mori. It is proposed that RH-5992 may cause negative effect specifically on reproductive characters like development of ovary and egg production due to decrease in 30 kDa protein.

Effect of juvenile hormone and ecdysone on initiating blood meal-dependent vitellogenic ovarian cycles in autogenous and anautogenous culex pipiens [Diptera: culicidae]

The effect of juvenile hormone [JH] and ecdysone on initiating blood meal - stimulated ovarian cycles was studied in autogenous [2[nd] ovarian cycle] and anautogenous [1[st] ovarian cycle] Cx. pipiens. Although vitellogenesis was initiated in both mosquitoes in response to ecdysone, JHI and sequential JHI-ecdysone treatments induced vitellogenesis in anautogenous females only. JHI treatment initiated vitellogenesis in Ca. 30% of anautogenous females and only half of those were able to form mature eggs. Sequential JHI- ecdysone treatment triggered vitellogenesis in 10 out of 25 anautogenous females and mature eggs were formed in three females only. In response to ecdysone, vitellogenesis in 10 out of 18 autogenous females and mature eggs were formed in two individuals. In Ca. 70% of anautogenous siblings vitellogenesis was initiated and in most of those females mature eggs were developed. Our data suggests that differences in hormone - dependent events of vitellogenesis in autogenous and anautogenous Cx. pipiens seem to be related to the regulation of ecdysteroide release

Effect of precocene II, ecdysone and juvenile Hormone on the glicogen concentration in pupae of Stomocys calcitram (Diptera muscidae)

Larvas de terceiro instar de Stomoxys calcitrans (L.) foram tratadas com precoceno II, ecdisona e hormônio juvenil. O desenvolvimento ocorreu até acontecer a pupaçäo, quando os níveis de glicogênio foram determinados. A administraçäo daquelas três substâncias interferiu na concentraçäo de glicogênio. O precoceno II causou uma diminuiçäo enquanto a ecdisona e o hormônio juvenil um aumento. A ecdisona administrada junto com o precoceno II reverteu o efeito do último, o que näo aconteceu quando o precoceno foi administrado junto com o hormônio juvenil. A ecdisona, administrada junto com o hormônio juvenil, causou reduçäo na concentraçäo do glicogênio

Differential gene activation in Drosophila melanogaster populations selected for developmental rate

Foi estudado no estágio de prepupa de zero hora, o padräo de puffs de populaçöes de Drosophila melanogaster submetidas por muitas geraçöes de seleçäo para diferenças na velocidade de desenvolvimento. Puffs com valores médios menores foram encontrados na populaçäo selecionada para velocidade lenta quando comparada com os das populaçöes controle e selecionada para desenvolvimento rápido. Com o balanço entre hormônio juvenil e ecdisona é o fator determinante da velocidade do desenvolvimento e como a ecdisona é responsável pelo início do ciclo de puffs (como por exemplo 47EF, 63E, 71CE e 82EF), nós sugerimos que diferenças na regulaçäo desses hormônios possam explicar as variaçöes nos padröes de puffs observadas aqui. Por outro lado, o padräo de puffs de hibridos entre estas populaçöes sugere que o controle de alguns puffs, como 66B, pode ser devido a um regulador em cis

Effects of juvenile hormone analogue on ecdysis prevention induced by precocene in Rhodnius prolixus (Hemiptera: Reduviidae).

Adicionado ao sangue alimentar na dose de 25 micros/ml o precoceno II causou um aumento no periodo de intermuda em ninfas de 4o. estadio de Rhodnius prolixus. Este atraso da muda foi relacionado com a diminuicao da area dos nucleos das celulas das glandulas protoracicas e com a queda da atividade mitotica das celulas da epiderme do inseto. Um analogo de hormonio juvenil aplicado topicamente (60 micros/inseto) junto com o tratamento oral com precoceno II preveniu a atrofia das glandulas protoracicas e induziu um aumento no numero de mitoses nas celulas da epiderme, diminuindo o periodo de intermuda nestes insetos.A possivel relacao entre a acao do hormonio juvenil e a producao de ecdisona pelas glandulas protoracicas e discutida

Ecdysteroids: biochemical mechanism of 20-hydroxyecdysone inactivation in Triatoma infestans (Hemiptera, Reduviidae).

Al inyectar 20-OH-ecdisona-3H en el 5o.estadio ninfal de T. infestans, se observo la transformacion de la misma a metabolitos muy polares (pico I). La mayor parte de los constituyentes del pico I evidenciaron ser glucurono-conjugados al ser analizados por hidrolisis enzimaticas. La acetilacion de los conjugados seguida por hidrolisis enzimatica permitio identificar las posiciones ocupadas por el acido glucuronico al inactivar la 20-OH-ecdisona.Al inyectar los conjutados radiactivos aislados (pico I) en ninfas del 5o. estadio, se observo que no se revierte el proceso de inactivacion

Curso internacional de entrenamiento de post-grado en Bioquínmica y toxicología de insectos / International course of training of post-grade in insect biochemis try and toxicology

Resume los contenidos de un cursos teórico-práctico dictado en la ciudad de Buenos Aires, sobre diversos aspectos de la bioquímica y toxicología de insectos: mecanismos hormonales, hormonas juveniles y ecdisona; metabolismo de lípidos y transporte de ecdisona en el Triatoma infestans; acción de insecticiadas; embriogénesis; biosítesis de componentes cuticulares (quitina) y metabólicos (trehalosa); y, cultivos de tejido de insectos

Mecanismos endocrinos en la regulación del desarrollo de triatominos / Endocrine mechanisms in the regulation of the development of triatominae

Se estudian los mecanismos endocrinos que intervienen en la regulación del desarrollo del Triatoma infestans y otros triatominos, analizándose el rol fisiológico que cumplen las hormonas juveniles (en la diferenciación al estadio adulto, como hormonas gonadotróficas en las hembras; y como estimulantes de la síntesis de feromonas en adultos), su concentración y metabolismo; así como la estructura, biosíntesis, transporte en la hemolinfa, concentración y metabolismo de la ecdisons (ecdisteroide)