共查询到20条相似文献,搜索用时 46 毫秒
1.
Mohsin Shaikh Huihui Zhang Hongyuan Wang Xiuli Guo Yunmei Song Jagat Rakesh Kanwar Sanjay Garg 《AAPS PharmSciTech》2017,18(1):130-137
Esophageal cancer (EC) mostly affects the elderly population and is frequently diagnosed at an advanced stage. Self-expanding metal stents (SEMS) are the most popular mode of palliation, but they are associated with reocclusion caused by tumor growth. To overcome this problem, docetaxel (DTX)-loaded polyurethane formulations were prepared for stent application. The films were evaluated against the cancer cell lines, OE-19 and OE-21, and normal esophageal cell line Het-1A. The DTX and the formulations were evaluated in vitro for the cytotoxicity and in vivo in nude mice. It was found that DTX and the formulations have a weak activity against the EC cell lines and an even weaker activity against Het-1A cell line. Preliminary in vivo studies showed skin toxicity in nude mice necessitating modification of the formulation. Reevaluation in a mouse xenograft model resulted in toxicity at high dose formulations while the low dose formulation exhibited modest advantage over commercial IV formulation; however, there was no significant difference between the commercial IV and blank formulation. DTX combination with an anti-cancer agent having complementary mode of action and non-overlapping toxicity could yield better outcome in future. 相似文献
2.
3.
Glioblastoma multiforme (GBM), the most common brain tumor in adults, is neurologically destructive and has a dismal response
to virtually all therapeutic modalities. One phenomenon that can contribute to this complexity is the presence of a relatively
small subset of glioma stem cells (GSCs) within the tumor and the activation of pathways that control cellular differentiation.
The Notch signaling pathway, which is responsible for maintaining a balance between cell proliferation and apoptosis, is believed to
be deregulated in cancer stem cells (CSCs), leading to tumor growth through the generation or expansion of CSCs. In this study,
Notch-1 small interfering RNA (siRNA) was used to silence Notch-1 gene expression in GSCs. An MTT assay demonstrated inhibitory effects on the proliferation of GSCs in vitro. Real-time PCR
showed that Notch-1 expression levels were markedly decreased in GSCs transfected with Notch-1 siRNA in vitro.
Notch-1 silenced GSCs engrafted on Balb/c nude mice showed a significantly greater reduction in oncogenicity than the control group
(P < 0.05). Furthermore, direct intratumoral injections of Notch-1-siRNA/PEI significantly delayed the growth of pre-established tumors in nude mice (P < 0.05). These results suggest that siRNA-mediated silencing of the Notch-1 gene may represent a novel target for gene therapy of GBM. 相似文献
4.
Persian poppy (Papaver bracteatum Lindl.) is an important commercial source of medicinal opiates and related compounds. In this research, calli were induced
from seeds, roots, cotyledons and hypocotyls of P. bracteatum at a high efficiency. The optimized callus induction media consisted of the Murashige and Skoog (MS) basic media supplemented
with 1.0 mg/L 2, 4-dichlorophenoxyacetic acid (2,4-D), 0.1 mg/L kinetin and 15 mg/L ascorbic acid. The concentrations of 2,4-D
and ascorbic acid were found critical to callus induction and proliferation. Subsequent subcultures resulted in excellent
callus proliferation. Ascorbic acid at concentration 15 mg/L increased the callus proliferation significantly. Maximum callus
growth was achieved when the explants were incubated at 25°C. MS salts at full strength were found inhibitory for callus induction,
while ľ MS salts were found to favor callus induction. Shoot regeneration of calli in vitro was achieved on ľ MS medium containing 0.5 mg/L benzylamine purine and 1.0 mg/L naphthalene acetic acid. Analysis of alkaloid
extracts from Persian poppy tissues by high-performance liquid chromatography showed that thebaine accumulated in the tissues
of plants. The thebaine alkaloid profile of the Persian poppy is a well-defined model to evaluate the potential for metabolic
engineering of thebaine production in P. bracteatum. 相似文献
5.
In this study, we have formulated chitosan-coated sodium alginate microparticles containing meloxicam (MLX) and aimed to investigate
the correlation between in vitro release and in vivo absorbed percentages of meloxicam. The microparticle formulations were prepared by orifice ionic gelation method with two
different sodium alginate concentrations, as 1% and 2% (w/v), in order to provide different release rates. Additionally, an oral solution containing 15 mg of meloxicam was administered
as the reference solution for evaluation of in vitro/in vivo correlation (ivivc). Following in vitro characterization, plasma levels of MLX and pharmacokinetic parameters [elimination half-life (t
1/2), maximum plasma concentration (C
max), time for C
max (t
max)] after oral administration to New Zealand rabbits were determined. Area under plasma concentration–time curve (AUC0–∞) was calculated by using trapezoidal method. A linear regression was investigated between released% (in vitro) and absorbed% (in vivo) with a model-independent deconvolution approach. As a result, increase in sodium alginate content lengthened in vitro release time and in vivo t
max value. In addition, for ivivc, linear regression equations with r
2 values of 0.8563 and 0.9402 were obtained for microparticles containing 1% and 2% (w/v) sodium alginate, respectively. Lower prediction error for 2% sodium alginate formulations (7.419 ± 4.068) compared to 1%
sodium alginate formulations (9.458 ± 5.106) indicated a more precise ivivc for 2% sodium alginate formulation. 相似文献
6.
This paper developed solvent-free drug-eluting implants for metronidazole delivery for the treatment of periodontal disease
and investigated the characteristics of the drug’s release from the implants, both in vitro and in vivo, using an HPLC assay. The metronidazole exhibited a two-stage release behavior in vitro with an initial burst release followed by a diffusion-controlled release and then a secondary burst release. The accumulated
drug release reached 100% on the 18th day, and the drug-eluting implant was totally dissolved on the same day. Additionally,
the drug-eluting disks were implanted within the sub-gingival space of both lower incisors of six rabbits. The curve of in vivo drug release was smoother and showed a predominantly diffusion-controlled release. The implants were totally dissolved at
2 weeks after implantation. The concentration of metronidazole remained above the MIC90 during the entire investigation. 相似文献
7.
The bioavailability of therapeutic agents from eye drops is usually limited due to corneal barrier functions and effective
eye protective mechanisms. Therefore, the current study aims to enhance ocular bioavailability of brimonidine, a potent antiglaucoma
drug, through the preparation of ocular inserts. Solvent casting technique was employed to prepare the inserts using polyvinylpyrrolidone
K-90 (PVP K-90) as film-forming polymer blended with different viscosity grades of bioadhesive polymers namely hydroxypropyl
methycellulose, carbopol, sodium alginate, and chitosan. The prepared ocular inserts were evaluated for various physicochemical
parameters, swelling behavior, and in vitro release patterns. Sodium alginate-based ocular inserts revealed the most sustainment in drug release (99% at 6 h), so it
was selected for further modifications via coating it, on one side or dual sides, using hydrophobic film composed of either
ethylcellulose or Eudragit RSPO. The obtained in vitro release results for the modified ocular inserts revealed that ethylcellulose is superior to Eudragit RSPO in terms of brimonidine
release sustainment effect. Ocular inserts composed of 7% PVP K-90, 1.5% low molecular weight sodium alginate with or without
ethylcellulose coat were able to sustain the in vitro release of brimonidine. Their therapeutic efficacy regarding intraocular pressure (IOP) lowering effect when inserted in
albino rabbits eyes showed superior sustainment effect compared with that of brimonidine solution. Furthermore, due to both
the mucoadhesive property and the drug sustainment effect, the one-side-coated ocular insert showed more IOP lowering effect
compared with that of its non-coated or dual-side-coated counterpart. 相似文献
8.
Youping Deng David R Johnson Xin Guan Choo Y Ang Junmei Ai Edward J Perkins 《BMC systems biology》2010,4(1):153
Background
Evolution of toxicity testing is predicated upon using in vitro cell based systems to rapidly screen and predict how a chemical might cause toxicity to an organ in vivo. However, the degree to which we can extend in vitro results to in vivo activity and possible mechanisms of action remains to be fully addressed. 相似文献9.
Summary
Acmella radicans var. radicans propagation was established in vitro. This plant belongs to the Asteraceae from which some species are known for their insecticide, fungicide and antibacterial
activity. The complete Murashige and Skoog (MS) medium was the best in assisting seed germination. In order to obtain shoots
in vitro, a complete MS medium and half-strength MS medium were assayed with explants from leaves, nodes, and internodes. The best
medium for shoot production was the half-strength MS medium with no addition of plant growth regulators, and the highest shoot
propagation was from single-node explants. Regeneration of roots on shoot explants in the medium was obtained without the
addition of growth regulators. Of the plantlets that were acclimated, 90% of them were obtained from rooted shoots with completely
expanded leaves. The alkamide content was evaluated for each tissue and the higher concentration was observed in flower heads.
The main alkamides present in the leaves and the flower heads were N-(2-phenylethyl)-2Z,4E-octadienamide and 3-phenyl-N-(2-phenylethyl)-2-propenamide. This study describes the methodology for the establishment and propagation of Acmella radicans in vitro and the evaluation of different tissue alkamide contents in vitro and in the field. 相似文献
10.
Esther E. Uchendu Gopinadhan Paliyath Dan C. W. Brown Praveen K. Saxena 《In vitro cellular & developmental biology. Plant》2011,47(6):710-718
North American ginseng (NAG) (Panax quinquefolius L.) is a medicinally important plant with multiple uses in the natural health product industry. As seed propagation is time-consuming
because of the slow growth cycle of the plant, in vitro propagation using a bioreactor system was evaluated as an effective approach to accelerate plant production. An efficient
method was developed to multiply nodal explants of NAG using liquid-culture medium and a simple temporary immersion culture
vessel. The effects of plant growth regulators, phenolics, and chemical additives (activated charcoal, melatonin, polyvinylpolypyrrolidone,
and ascorbic acid) were evaluated on in vitro-grown NAG plants. The highest number (12) of shoots per single node was induced in half-strength Schenk and Hildebrandt basal
medium containing 2.5 mg/l kinetin, in which 81% of the cultured nodes responded. In a culture medium with 0.5 mg/l α-naphthalene
acetic acid (NAA), roots were induced in 78% of the explants compared to 50% with a medium containing indole-3-acetic acid.
All of the resulting plants appeared phenotypically normal, and 93% of the rooted plants were established in the greenhouse.
Phenolic production increased significantly (P < 0.05) over a 4-wk culture period with a negative impact on growth and proliferation. Activated charcoal (AC; 50 mg/l) significantly
reduced total phenolic content and was the most effective treatment for increasing shoot proliferation. Shoot production increased
as the phenolic content of the cultures decreased. The most effective treatment for NAG development from cultured nodal explants
in the bioreactor was 2.5 mg/l kinetin, 0.5 mg/l NAA, and 50 mg/l AC in liquid culture medium. This protocol may be useful
in providing NAG tissues or plants for a range of ginseng-based natural health products. 相似文献
11.
Summary Coconut (Cocos nucifera L.) plantlets grown in vitro often grow slowly when transferred to the field possibly, due to a limited photosynthetic capacity of in vitro-cultured plantlets, apparently caused by the sucrose added to growth medium causing negative feedback for photosynthesis.
In this paper, we tested the hypothesis that high exogenous sucrose will decrease ribulose 1,5-bisphosphate carboxylase (Rubisco)
activity and photosynthesis resulting in limited ex vitro growth. Plantlets grown with high exogenous sucrose (90 gl−1) had reduced photosynthetic activity that resulted in a poor photosynthetic response to high levels of light and CO2. These plantlets also had low amounts of Rubisco protein, low Rubisco activity, and reduced growth despite showing high survival
when transferred to the field. Decreasing the medium’s sucrose concentration from 90 to 22.5 gl−1 or 0 gl−1 resulted in increased photosynthetic response to light and CO2 along with increased Rubisco and phosphoenolpyruvate carboxylase (PEPC) activities and proteins. However, plantlets grown
in vitro without exogenous sucrose died when transferred ex vitro, whereas those grown with intermediate exogenous sucrose showed intermediate photosynthetic response, high survival, fast
growth, and ex vitro photosynthesis. Thus, exogenous sucrose at moderate concentration decreased photosynthesis but increased survival, suggesting
that both in vitro photosynthesis and exogenous sucrose reserves contribute to field establisment and growth of coconut plantlets cultured in vitro. 相似文献
12.
Yanfeng Tuo Lanwei Zhang Xue Han Ming Du Yingchun Zhang Huaxi Yi Weiqin Zhang Yuehua Jiao 《World journal of microbiology & biotechnology》2011,27(3):505-511
The objective of this study was to evaluate the in vitro immunomodulating capacity of Lactobacillus
coryniformis subsp torquens T3L (L.
coryniformis T3L) isolated from traditional fermented yak’s milk in Tibet, China, and Lactobacillus paracasei supsp. paracasei M5L (L. paracasei M5L)isolated from kumiss in Sinkiang, China was used as control. The effects of live bacteria, cell wall and genomic DNA
of the two Lactobacillus strains on human peripheral blood mononuclear cells (PBMCs) proliferation, production of interleukin-12 (IL-12 p70), interferon
gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α), and natural killer (NK) cell activity were assessed. The live bacteria,
cell wall and genomic DNA of the two lactobacilli exerted proliferative effects on PBMCs. Live bacteria at 1 × 106 c.f.u. ml−1, cell wall at 20 μg protein ml−1 and DNA at 50 μg DNA ml−1 of the strainS induced the secretion of IL-12 (p70), IFN-γ and TNF-α by PBMCs. NK cell activities increased after cultivation
of PBMCs with live bacteria, cell wall and DNA of the strains. Overall, these results demonstrate that the live bacteria,
cell wall and genomic DNA of the two Lactobacillus strains exhibit immunomodulating activity. 相似文献
13.
This study describes the development of a micropropagation protocol for Pinguicula vulgaris using cultures initiated from in vitro produced seedlings. P. vulgaris is a carnivorous plant with a northern, disjunctly circumpolar distribution and specific habitat requirements, and is hence becoming increasingly rare. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher proliferation rates in 1/4MS, but was not affected by the addition of 0.1 mg/L 6-benzyladenine (BA) or zeatin (Zea). The best medium for propagating P. vulgaris was plant growth regulator (PGR) free ¼MS. An average of 7.62 new shoots per initial explant could be obtained after 8 weeks of culture, of which over 79% produced roots during proliferation. Moreover, rooting percentages of 100% were obtained for the initial explants in all the tested media, including media without PGRs. The plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. 相似文献
14.
In vitro culture is an important aid for ex situ conservation of rare, endemic or threatened plants. In this work, we establish an efficient method for the seed germination,
seedling development, and axillary shoot propagation of Centaurea zeybekii Wagenitz. The seeds, collected from a wild population, were surface sterilised and cultured on various in vitro germination media. The effects of photoperiod and temperature on seed germination were also investigated. Germinations were
obtained after 6 weeks in culture and the radicle emergence was evaluated as a main indicator. A high frequency of germination
was obtained on distilled water supplemented with vitamines and 1 mg/L GA3. Although the seed germination frequencies were not affected by photoperiod, the highest germination frequency was obtained
at 24 ± 2°C. A high frequency of axillary shoot proliferation was produced on MS medium supplemented with 1 mg/L BA. Then,
the axillary shoots were separated and transferred to MS medium with or without plant growth regulators for rooting. Rhizogenezis
was promoted after 6 weeks only in MS and 1/2 MS media containing 0.5 mg/L IBA. The rooting process was very slow and the
percentage of shoot rooting was also very low (15%).
The present study not only enables reinforcement of wild plant populations using ex situ growth of individuals, but it also helps to large number of aseptic seedling to use it in clonaly micropropagation studies. 相似文献
15.
Ana Cristina Tavares Lígia R. Salgueiro Jorge M. Canhoto 《In vitro cellular & developmental biology. Plant》2010,46(1):47-56
Daucus carota subsp. halophilus, is a wild crop relative of domestic carrot. It is an aromatic plant widely used in folk medicine due to recognized therapeutic
properties of its essential oils. Experiments were carried out to evaluate the potential of in vitro propagation techniques to the conservation of this endemic and endangered taxon. The results showed that shoot tips of in vitro germinated seeds were able to proliferate in the presence of benzyladenine, with the best results being achieved using 4.4 μM,
both in the first and second cultures. Shoots rooted after being transferred to 1/2-Murashige and Skoog basal medium. The
results indicated that the concentration of benzyladenine used during the multiplication phase did not interfere with the
rate of root formation. The obtained plantlets were morphologically and anatomically identical to those obtained by seeds.
Some of the in vitro produced shoots developed flowers that produced viable pollen. Plant regeneration was also achieved by somatic embryogenesis
induction in cotyledons and root segments cultured in the presence of 4.5 μM 2,4-dichlorophenoxyacetic acid. Somatic embryos
converted into plantlets in a medium without growth regulators. Plants obtained either by shoot proliferation or somatic embryogenesis
were acclimatized and are now growing at the Coimbra Botanical Garden. The first attempts to reintroduce these plants in the
original habitat were successful. It can be concluded that the protocols developed are a useful approach to the conservation
of this endemic species. 相似文献
16.
This paper describes multiple shoot regeneration from leaf and nodal segments of a medicinally important herb Centella asiatica L. on Murashige and Skoog’s (MS) medium supplemented with a range of growth regulators. The highest number of multiple shoots
was observed on MS augmented with 3.0 mg dm−3 N6-benzylaminopurine (BAP) and 0.05 mg dm−3 α-naphthaleneacetic acid (NAA). Leaf explant showed maximum percentage of cultures regenerating shoots (81.6 %), with the
highest shoot number (8.3 shoots per explant) and the shoot length (2.1 cm) whereas, nodal explant showed less number of shoots
with callus formation at the base cut end. Successive shoot cultures were established by repeatedly sub-culturing the original
explant on a fresh medium. Rooting of in vitro raised shoots was best induced on half strength MS supplemented with 0.5 mg dm−3 indole-3-butyric acid (IBA) with highest percentage of shoot regenerating roots (76.8 %) with 3–4 roots per shoot. Plantlets
were acclimated in Vermi-compost and eventually established in soil. Contents of chlorophyll, total sugars, reducing sugars and proteins were estimated in
leaf tissue from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants, whereas other three components were higher in in vitro plants. 相似文献
17.
Elif Aylin Ozudogru Ergun Kaya Emrah Kirdok Saliha Issever-Ozturk 《In vitro cellular & developmental biology. Plant》2011,47(2):309-320
An efficient in vitro propagation protocol, applicable both to young and mature explants of two Thymus spp., results in genetically stable plantlets. In vitro-grown shoot tips of Thymus vulgaris L. were exposed to cytokinins (6-benzyladenine, kinetin, and thidiazuron) alone or in combination with auxins, gibberellic
acid (GA3) and/or silver nitrate in order to optimize in vitro shoot proliferation. Optimum shoot proliferation (97% regeneration rate, with 8.6 shoots produced per explant) was obtained
when semi-solid Murashige and Skoog (MS) medium was supplemented with 1 mg L−1 kinetin and 0.3 mg L−1 GA3. Rooting of the shoots was easily obtained on semi-solid MS medium that was either hormone-free or supplemented with auxins.
However, the best root apparatus (92.5% rooting rate, with 19 adventitious roots per shoot) developed on MS medium supplemented
with 0.05 mg L−1 2,4-dichlorophenoxyacetic acid. Genetic stability was confirmed in the in vitro-germinated mother plant as well as the shoots that underwent two, four, six, eight, or ten cycles of in vitro subculturing by random amplified polymorphic DNA (RAPD) analysis. When applied to the micropropagation of mature shoot tips
of T. longicaulis C. Presl subsp. longicaulis var. subisophyllus (Borbás) Jalas, the optimized in vitro propagation protocol resulted in a 97.5% shoot regeneration rate, with five shoots formed per explant, and 100% rooting.
Rooted plantlets of both species were transferred to 250-mL plastic pots and successfully acclimatized by gradually reducing
the relative humidity. 相似文献
18.
Mature osteoclasts, multinucleated giant cells responsible for bone resorption, are terminally differentiated cells with a
short life span. Recently, we have demonstrated that osteoclast apoptosis is regulated by ERK activity and Bcl-2 family member
Bim. In this paper, we summarize the methods we used to study osteoclast apoptosis in vitro and in vivo. Using adenovirus and retrovirus vectors, we were able to introduce foreign genes into osteoclasts and examine their effects
on osteoclast survival in vitro. In addition, we established the modified methods for in situ hybridization and BrdU labeling of bone sections from mice
to study osteoclast survival in vivo. The detailed methods described here could be useful for studying the biological process in bone. 相似文献
19.
Summary We describe an in vitro propagation protocol for Zingiber petiolatum (Holttum), I. Theilade, a rare species from the southern part of Thailand. Fruits were surface-sterilized and seeds germinated
on Murashige and Skoog medium (MS) medium supplemented with 3% sucrose. Three-month-old seedlings were used as initial plant
material for in vitro propagation. Terminal buds of the plants were inoculated on MS medium containing 6-benzylaminopurine (BA; 2.2–35.5 μM) alone or in combination with 1-naphthaleneacetic acid (0.5 μM). Eight weeks after inoculation, the cultures were transferred to MS medium without plant growth regulators for 4wk. The
cultures transferred from MS medium with 17.8 μM BA revealed the highest shoot induction rate of 6.1±0.7 shoots per explant. Rooting was spontaneously achieved in MS medium
without plant growth regulators. Rooted plants were successfully transplanted to soil. 相似文献
20.
Glycolipid biosurfactant (GLB) from Rhodococcus ruber IEGM 231 was found to stimulate tumor necrosis factor-α (TNF-α), interleukin (IL) -1β and IL-6 production when applied as
an ultrasonic emulsion to the adherent human peripheral blood monocyte culture. However, a lack of cytokine-stimulating activity
was registered with the GLB applied as a hydrophobic film coating in 24-well culture plates, indicating that it may have been
due to its inhibitory effect on monocyte adhesion. The mode of GLB application may therefore play an important role in in
vitro assay of immunostimulatory activity of this compound as well as other bacterial glycolipids. Additionally, GLB from
R. ruber displayed no cytotoxicity against human lymphocytes and therefore could be proposed as a potential immunomodulating and antitumor
agent. 相似文献