RESUMO
Thirty-one endophytic streptomycete and non-streptomycete actinobacteria were isolated from healthy date palm root tissues. In vitro screening revealed that the antifungal action of isolate #16 was associated with the production of cell-wall degrading enzymes, whereas with diffusible antifungal metabolites in isolate #28, albeit their production of volatile antifungal compounds. According to the 16S rRNA gene sequencing, isolates #16 and #28 were identified as Streptomyces polychromogenes UAE2 (Sp; GenBank Accession #: OK560620) and Streptomyces coeruleoprunus UAE1 (Sc; OK560621), respectively. The two antagonists were recovered from root tissues until 12 weeks after inoculation, efficiently colonized root cortex and xylem vessels, indicating that the date palm roots are a suitable habitat for these endophytic isolates. At the end of the greenhouse experiments, the development of sudden decline syndrome (SDS) was markedly suppressed by 53% with the application of Sp and 86% with Sc, confirming their potential in disease management. Results showed that the estimated disease severity indices in diseased seedlings were significantly (p < 0.05) reduced from 4.75 (scale of 5) to 2.25 or 0.67 by either Sp or Sc, respectively. In addition, conidial numbers of the pathogen significantly (p < 0.05) dropped by 38% and 76% with Sp and Sc, respectively, compared to infected seedlings with F. solani (control). Thus, the suppression of disease symptoms was superior in seedlings pre-inoculated with S. coeruleoprunus, indicating that the diffusible antifungal metabolites were responsible for F. solani retardation in these plants. This is the first report of actinobacteria naturally existing in date palm tissues acting as microbial antagonists against SDS on date palm.
RESUMO
To manage stem canker disease on royal poinciana, actinobacterial isolates were used as biological control agents (BCAs) based on their strong in vitro inhibitory effects against Neoscytalidiumdimidiatum. Streptomyces griseorubens UAE2 and Streptomyces wuyuanensis UAE1 had the ability to produce antifungal compounds and cell-wall-degrading enzymes (CWDEs). Only S. griseorubens, however, restored the activity of 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD). In vivo apple fruit bioassay showed that lesion development was successfully constrained by either isolates on fruits inoculated with N. dimidiatum. In our greenhouse and container nursery experiments, S. griseorubens showed almost complete suppression of disease symptoms. This was evident when the preventive treatment of S. griseorubens significantly (p < 0.05) reduced the numbers of conidia of N. dimidiatum and defoliated leaves of royal poinciana seedlings to lesser levels than when S. wuyuanensis was applied, but comparable to control treatments (no pathogen). The disease management of stem canker was also associated with significant (p < 0.05) decreases in ACC levels in royal poinciana stems when S. griseorubens was applied compared to the non-ACCD-producing S. wuyuanensis. This study is the first to report the superiority of antagonistic actinobacteria to enhance their effectiveness as BCAs not only for producing antifungal metabolites and CWDEs but also for secreting ACCD.
RESUMO
The main objective of this study was to improve the inclusion formation between itraconazole and beta-cyclodextrin and thus enhance dissolution amount and bioavailability characteristics of itraconazole. Inclusion complexes between itraconazole and beta-cyclodextrin were prepared using simple physical mixing, conventional coprecipitation method, and supercritical carbon dioxide (SC CO(2)). Effects of process variables (temperature, pressure) and drug:cyclodextrin ratio on inclusion yield and thermal behavior of the solid complexes prepared by SC CO(2) were studied and compared to those obtained by physical mixing and coprecipitation methods. In addition, dissolution amounts of the products obtained by different methods were measured in gastric fluid. Finally, pharmacokinetic studies of the inclusion complexes were conducted in male Wistar rats to assess the bioavailability of the prepared complexes. Results showed that temperature, pressure and itraconazole:beta-cyclodextrin ratio had significant effects on the inclusion yield of the complex prepared by SC CO(2) method. Higher inclusion yields were obtained in the SC CO(2) method as compared to physical mixing and coprecipitation methods. In vivo drug pharmacokinetic studies showed that the itraconazole-beta-cyclodextrin product prepared using SC CO(2) gave higher bioavailability of itraconazole (in blood, liver and kidney of male Wistar rats) as compared to the products obtained by physical mixing or coprecipitation methods.
Assuntos
Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico/métodos , Itraconazol/química , Itraconazol/farmacocinética , beta-Ciclodextrinas/química , beta-Ciclodextrinas/farmacocinética , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Dióxido de Carbono/farmacocinética , Precipitação Química , Composição de Medicamentos , Excipientes , Suco Gástrico/química , Masculino , Pressão , Ratos , Ratos Wistar , Solubilidade , Espectrofotometria Ultravioleta , Temperatura , Distribuição TecidualRESUMO
We compare the effects of estrogen and/or ghrelin on vascular counts and collagen I/III ratio of urethral and anal canal submucosa in old vs young-adult ovariectomized rats. Ovariectomized Fisher 344 rats (18 and 3 months old, n = 24 x 2) received 42 daily intraperitoneal 17-ss estradiol (10 microg/kg), ghrelin (2 microg/kg), both, or vehicle (n = 6 x 4 per group). Blood vessel counts and collagen I/III ratio were measured, respectively, by light microscopy and Western blot analysis with immunohistochemistry of ghrelin receptors. Estrogen significantly increased urethral and anal vascular counts and collagen I/III ratio in young-adult rats. In old rats, only combined estrogen/ghrelin administration significantly increased both variables. This was not observed with estrogen or ghrelin separately. Ghrelin receptors were immunostained in urethral and anal submucosa of all samples. Combined estrogen/ghrelin administration restored postovariectomy urethral and anal canal submucosal vessel number and collagen I/III ratio in old rats suggesting independent ageing effect.
Assuntos
Canal Anal/irrigação sanguínea , Colágeno Tipo III/metabolismo , Colágeno Tipo I/metabolismo , Estradiol/administração & dosagem , Grelina/administração & dosagem , Neovascularização Fisiológica/efeitos dos fármacos , Ovariectomia , Uretra/irrigação sanguínea , Fatores Etários , Canal Anal/metabolismo , Animais , Estradiol/farmacologia , Feminino , Grelina/farmacologia , Mucosa/irrigação sanguínea , Mucosa/metabolismo , Ratos , Ratos Endogâmicos F344 , Uretra/metabolismoRESUMO
The aim of this study was to compare the effects of ageing and ovariectomy on biomarkers of urogenital ageing in old and young-adult rats. Fisher 344 rats (18- and 3-months-old, n = 6 x 2) underwent ovariectomy. Age-matched sham animals received no intervention (n = 6 x 2). One month later, biomarkers of urogenital ageing were evaluated (light microscopic count of urethral and anal canal submucosal blood vessels, Western blot analysis of urethral, and anal canal submucosal collagen I and III and cytoplasmic p27(kip1) expression in the striated urethral and anal sphincters and levator ani and gel electrophoresis of isomyosin I proportion in these muscles) and compared in all groups (n = 24). All biomarkers of urogenital ageing studied were significantly increased in old compared to young-adult sham rats. Ovariectomy significantly increased these changes further in old versus young-adult rats with either smaller or larger differential effect than ageing compared to young-adult sham animals. Ovariectomy significantly exacerbates normative urogenital ageing changes in rats.
Assuntos
Envelhecimento/metabolismo , Colágeno Tipo III/metabolismo , Colágeno Tipo I/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Ovariectomia , Uretra/irrigação sanguínea , Uretra/metabolismo , Envelhecimento/patologia , Animais , Biomarcadores/metabolismo , Estrogênios/metabolismo , Feminino , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Diafragma da Pelve/patologia , Ratos , Ratos Endogâmicos F344 , Uretra/patologiaRESUMO
OBJECTIVES: Urinary and fecal control deteriorates after menopause, but it is not clear whether this is age or hormone related. This study investigates whether administration of estrogen and/or the anti-aging growth hormone-releasing peptide, ghrelin, improves the adverse effects of menopause/aging on urethral and anal canal submucosal blood vessel counts in middle-age rats. METHODS: Female Wistar rats (13 months old) underwent ovariectomy, followed 1 month later by intraperitoneal once-daily administration of 17-beta estradiol (10 microg/kg), ghrelin (2 microg/kg), both hormones, or vehicle (n = 6 in each of four groups) for 42 days. An age-matched sham group (n = 6) received no intervention. Submucosal blood vessels were counted by light microscopy in five randomly selected fields from five nonconsecutive sections (5 microm thick) per rat of formalin-fixed and paraffin-embedded tissue blocks of the urethra and anal canal stained with hematoxylin-eosin. The results are expressed as the mean vessel number per high power field (x400). RESULTS: Ovariectomy significantly reduced submucosal urethral and anal vascular counts below the sham values (7.41 +/- 0.98 versus 5.46 +/- 0.82, P = 0.003 and 7.16 +/- 1.11 versus 4.92 +/- 0.65, P = 0.0009, respectively). Estrogen restored the urethral counts (7.76 +/- 0.88, P = 0.5) and ghrelin or combined estrogen and ghrelin administration significantly increased the counts to greater than the sham counts (8.68 +/- 0.99, P = 0.04 and 9.72 +/- 1.21, P = 0.004, respectively). Estrogen, ghrelin, and combined estrogen and ghrelin administration also restored the anal counts to sham levels (7.26 +/- 0.97, P = 0.8; 6.56 +/- 0.78, P = 0.3; and 7.76 +/- 0.88, P = 0.3, respectively). CONCLUSIONS: Combined or individual replacement of estrogen and ghrelin produces a beneficial effect by reversing the ovariectomy-induced decrease in urethral and anal canal submucosal vessel numbers in middle-age rats.