RESUMO
The roots of Trichosanthes kirilowii (TK) have been used in traditional oriental medicine for the treatment of respiratory diseases. In this study, we investigated whether an ethanolic root extract of TK (ETK) can regulate the metastatic potency of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant human lung cancer cells. The relative migration and invasion abilities of erlotinib-resistant PC9 (PC9/ER) and gefitinib-resistant PC9 (PC9/GR) cells were higher than those of parental PC9 cells. Mesenchymal markers were overexpressed, whereas epithelial markers were downregulated in resistant cells, suggesting that resistant cells acquired the EMT phenotype. ETK reduced migration and invasion of resistant cells. The expression levels of N-cadherin and Twist were downregulated, whereas Claudin-1 was upregulated by ETK, demonstrating that ETK suppresses EMT. As a molecular mechanism, Src was dephosphorylated by ETK. The anti-metastatic effect of ETK was reduced by transfecting PC9/ER cells with a constitutively active form of c-Src. Dasatinib downregulated N-cadherin, Twist, and vimentin, suggesting that Src regulates EMT in resistant cells. Notably, CuB played a key role in mediating the anti-metastatic activity of ETK. Collectively, our results demonstrate that ETK can attenuate the metastatic ability of EGFR-TKI-resistant lung cancer cells by inhibiting Src-mediated EMT.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Trichosanthes , Humanos , Neoplasias Pulmonares/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Trichosanthes/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , CaderinasRESUMO
BACKGROUND: The treatment of diabetes with plant ingredients such as in Traditional Chinese Medicine (TCM) is an alternative to classical chemotherapy. OBJECTIVE: This study aims to explore the hypoglycemic effect of Trichosanthes pericarpium powder (TP) and intestinal bacteria transplantation in type 2 diabetic mice. The relationship between intestinal bacteria transplantation and improvement in insulin resistance was also investigated. METHODS: The polyphenols and terpenoids in the TP were identified by LC-MS/MS. Streptozotocin was used to induce a mouse model of type 2 diabetes. Diabetic mice were treated with different doses of TP and the intestinal bacteria obtained from the high-dose TP group for four weeks. RESULTS: As a result, FBG levels were found to be significantly reduced in diabetic mice, weight gain and organ enlargement were alleviated, and insulin resistance was significantly improved. TP administration also improved the disorder in intestinal bacteria in diabetic mice. Besides, TP can increase the liver AMPK, SIRT1, GLUT1, and GLUT4 gene expression, while down-regulated PEPCK and G6Pase gene expression suggest a potential mechanism for hypoglycemia in diabetic mice. CONCLUSION: Oral administration of Trichosanthes pericarpium powder in the treatment of diabetes may be achieved by restoring hepatic function, improving insulin resistance, and the dynamic balance of intestinal bacteria.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Trichosanthes , Camundongos , Animais , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Trichosanthes/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Cromatografia Líquida , Pós/metabolismo , Pós/farmacologia , Pós/uso terapêutico , Glicemia/metabolismo , Espectrometria de Massas em Tandem , Bactérias/metabolismo , Insulina/metabolismo , FígadoRESUMO
Background: Oxidative stress is an important cause of liver disease and atherosclerosis. Natural substances with antioxidant activity are good drugs for treating liver disease and atherosclerosis. Trichosanthes kirilowii Peel Polysaccharide (TKPP) can remove DPPH (2,2-Diphenyl-1-picrylhydrazyl) free radicals and hydroxyl free radicals in vitro, which shows antioxidant activity. Therefore, it is speculated that it can protect human hepatoma cell line (HepG2) and umbilical artery smooth muscle cell (HUASMC) against oxidative damage by hydrogen peroxide (H2O2). Methods: Oxidative damage cell models of HepG2 and HUASMC were induced by H2O2. HepG2 and HUASMC were divided into blank group, H2O2 injury group, TKPP treatment group, and glutathione (GSH) positive control group. Cell Counting Kit-8 (CCK-8) was used to detect cell viability. The level of total GSH and the amount of Nitric oxide (NO) secreted by cells were detected by specific kits. The gene and protein expressions of catalase (CAT) and superoxide dismutase (SOD) were detected by fluorescence quantitative PCR and Western Blot. Results: In these two kinds of cells, compared with the control group, the survival rate, total GSH level, and NO secretion, CAT and SOD gene and protein expressions were significantly decreased in the H2O2 damaged group. In the TKPP treatment group, the cell survival rate was significantly elevated with the increase of the polysaccharide concentration, and the total GSH level, NO secretion, CAT and SOD gene expression, and protein expression levels were also significantly increased. Conclusion: TKPP can improve the activities of HepG2 and HUASMC cells damaged by H2O2 and protect the cellular antioxidant system.
Assuntos
Aterosclerose , Trichosanthes , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Glutationa/metabolismo , Glutationa/farmacologia , Humanos , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo , Polissacarídeos/farmacologia , Superóxido Dismutase/metabolismo , Superóxido Dismutase/farmacologia , Trichosanthes/metabolismoRESUMO
MAIN CONCLUSION: Two key amino acids of isomultiflorenol synthase, Y125 and M254, were first proposed. They could be associated with the production of isomultiflorenol. Oxidosqualene cyclases (OSCs) are the first committed enzymes in the triterpenoid biosynthesis by converting 2,3-oxidosqualene to specific triterpenoid backbones. Thus, these enzymes are potential targets for developing plant-active compounds through the study of triterpenoid biosynthesis. We applied transcriptome information and metabolite profiling from Trichosanthes cucumerina L. to define the diversity of triterpenoids in this plant through OSCs. Isomultiflorenol synthase and cucurbitadienol synthase were previously identified in this plant. Here, three new OSCs, TcBAS, TcLAS, and TcCAS, were cloned and functionally characterized as ß-amyrin synthase, lanosterol synthase, and cycloartenol synthase activities, respectively. We also took advantage of the multiple sequence alignment and molecular docking of OSCs exhibiting in this plant and other plant OSCs to identify key residues associated with isomultiflorenol synthase specificity. Two novel key amino acids, referred to the Y125 and M254, were first discovered. These results provide information on a possible catalytic mechanism for plant OSCs that produce specific products.
Assuntos
Transferases Intramoleculares , Trichosanthes , Triterpenos , Aminoácidos , Clonagem Molecular , Transferases Intramoleculares/genética , Transferases Intramoleculares/metabolismo , Simulação de Acoplamento Molecular , Esqualeno/análogos & derivados , Especificidade por Substrato , Trichosanthes/metabolismo , Triterpenos/metabolismoRESUMO
This study investigates the effects of the water-soluble and organic-soluble Trichosanthes extracts on the hyperglycemic condition in streptozotocin- (STZ-) induced diabetic rats. The blood glucose levels, body weights, water intake, and urine volumes of rats in different experimental groups were monitored throughout the experiment, and the results obtained indicate that the two extracts can effectively reduce blood sugar levels, increase body weights, and improve water intake and urine volumes in diabetic rats. Based on blood biochemical analyses, the two extracts play an important role in regulating the diabetes-induced lipid metabolism disorder, increasing the levels of insulin and C-peptide, and alleviating the symptoms of diabetes. The variation in the liver glycogen contents of the water-soluble fraction and ethanol fraction groups suggests that the mechanisms underlying the hypoglycemic effects of the two extracts are different. Indeed, the water-soluble fraction alleviates diabetes symptoms in rats mainly by antioxidative activity, unlike the ethanol fraction.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Extratos Vegetais/metabolismo , Trichosanthes/metabolismo , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/fisiopatologia , Modelos Animais de Doenças , Hipolipemiantes/metabolismo , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Insulina/sangue , Insulina/metabolismo , Insulina/uso terapêutico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , RatosRESUMO
KEY MESSAGE: De novo transcriptome analysis from callus, leaf, and fruit of Trichosanthes cucumerina L. for the identification of genes associated with triterpenoid biosynthesis, especially bryonolic acid and cucurbitacin B. Trichosanthes cucumerina L. (TC) has been used as a medicinal plant in Thailand with various potential functions. Two major triterpenoids found in this plant, bryonolic acid and cucurbitacin B, are receiving increased attention for their activities. Here, we provide TC transcriptome data to identify genes involved in the triterpenoid biosynthetic pathway through callus, where was previously suggested as a novel source for bryonolic acid production as opposed to leaf and fruit. A de novo assembly of approximately 290-thousand transcripts generated from these tissues led to two putative oxidosqualene cyclases: isomultiflorenol synthase (IMS) and cucurbitadienol synthase (CBS). TcIMS and TcCBS, genes that encode substrates for two characteristic triterpenoids in cucurbitaceous plants, were identified as isomultiflorenol synthase and cucurbitadienol synthase, respectively. These two genes were functionally characterised in mutant yeast Gil77 systems, which led to the productions of isomultiflorenol and cucurbitadienol. Moreover, the callus-specific gene expression profiles were also presented. These obtained information showed candidate cytochrome P450s with predicted full-length sequences, which were most likely associated with triterpenoid biosynthesis, especially bryonolic acid. Our study provides useful information and a valuable reference for the further studies on cucurbitaceous triterpenoids.
Assuntos
Proteínas de Plantas/genética , Trichosanthes/genética , Trichosanthes/metabolismo , Triterpenos/metabolismo , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Transferases Intramoleculares/genética , Transferases Intramoleculares/metabolismo , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMO
Gold nanoparticles (AuNPs) is the most excellent anticancer theranostic nanoparticles synthesized through efficient, simple and green synthesis method using extracts of Trichosanthes kirilowii, extensively characterized by UV-spectroscopy, FT-IR and TEM techniques. The AuNPs, synthesized by means of T. kirilowii extracts identified that nanoparticles were â¼50 nm in size, which is an admirable nano dimension attained by green synthesis. In agreement with the outcome of microscopic cellular morphological observations, MTT assay showed effective, selective, anticarcinogenic effect of AuNPs on HCT-116 cells in a dose-dependent manner. The AuNPs significantly enhance ROS generation, cause mitochondrial membrane damage and induce morphological changes using AO/EtBr staining assay. Furthermore, AuNPs treatment induces G0/G1 phase cell-cycle arrest in HCT-116 cells. Also, AuNPs treatment activates caspase expression and downregulates the anti-apoptotic expression in HCT-116 cells. Our results point out that the phytoconsituents isolated from T. kirilowii can act as appropriate reducing and stabilizing agents in the properties of AuNPs; hereby, it leads to the green synthesis of an anti-carcinogenic agent with highly efficient potential for cancer treatment.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias do Colo/patologia , Ouro/química , Ouro/farmacologia , Nanopartículas Metálicas , Trichosanthes/metabolismo , Anticarcinógenos/química , Anticarcinógenos/metabolismo , Anticarcinógenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Ouro/metabolismo , Células HCT116 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacosRESUMO
Most herbs of traditional Chinese medicine (TCM) are used as air-dried decoction pieces that are manufactured and kept at ambient temperature for long periods. Given the ability of some desiccation-tolerant plants to conserve RNA, it could be worthwhile to isolate mRNA from TCM decoction pieces as part of a transcriptomic strategy to identify new substances with potential pharmaceutical application. Here, we report the molecular cloning of a novel trypsin inhibitor (as the probable alleleic variants TKTI-2 and TKTI-3) from the decoction piece of Radix Trichosanthis, representing the dried root of Trichosanthes kirilowii. From this material, the total RNA was extracted and a cDNA library was constructed from the isolated mRNA from which the cDNAs of two precursors were successfully cloned and sequenced. TKTI-3 showed an amino-acid substitution in the otherwise highly-conserved P1-P1' reaction site of the mature peptide, which we confirmed to not be an artefact. Subsequent analysis using LC-MS/MS detected the presence of specific tryptic peptides expected from TKTI-3, confirming the presence and expression of this locus in Radix Trichosanthis. More generally, this study indicates that mRNA can persist in decoction pieces and so could present a viable option for the molecular cloning from other TCMs.
Assuntos
Medicamentos de Ervas Chinesas/química , RNA/genética , Trichosanthes/metabolismo , Inibidores da Tripsina/isolamento & purificação , Clonagem Molecular , Espectrometria de Massas em Tandem/métodos , Trichosanthes/genéticaRESUMO
Lectins are a group of proteins or glycoproteins with various potentially exploitable bioactivities and have been capturing more interest recently. They have been isolated and reported from various tissues of a diversity of plant species. Tubers are modified and enlarged plant structures derived from stems or roots that are used for nutrient storage and asexual reproduction. A number of plants such as yam, taro and potato are grown for their edible tubers, and lectins are found to be one of the major storage proteins. These lectins exhibit potent bioactivities encompassing mitogenic, antitumor, antimicrobial, immunomodulatory, antioxidative, hypoglycemic, insecticidal and nematicidal activities. They are potential resources for development into functional or healthy foods and targets for food protein researchers.
Assuntos
Lectinas/metabolismo , Arisaema/metabolismo , Dioscorea/metabolismo , Lectinas/química , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Trichosanthes/metabolismoRESUMO
Ribosome-inactivating proteins have been isolated from Trichosanthes kirilowii root tubers and seeds, including trichosanthin, karasurin and T 33 from root tubers and trichosanthrip, trichokirin, alpha-kirilowin, beta-kirilowin and trichoanguin from seeds. The aforementioned proteins show structural and functional similarities. Among them trichosanthin is the best known and most intensely studied. Trichosanthin manifests anticancer activity in vitro and in tumor bearing mice against a variety of cancers/cancer cell lines. It also exhibits anti-HIV-1 and anti-HSV-1 activities. Trichosanthin has been found to be useful for treatment of cesarean scar pregnancies and ectopic pregnancy, and for preventing acute rejection of major histocompatibility complex-mismatched mouse skin allograft. Trichosanthin selectively lesions some neurons and thus can be used in neuroscience research.
Assuntos
Proteínas Inativadoras de Ribossomos/química , Proteínas Inativadoras de Ribossomos/farmacologia , Trichosanthes/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Cesárea/efeitos adversos , Cicatriz/tratamento farmacológico , Cicatriz/etiologia , Feminino , Rejeição de Enxerto , Humanos , Camundongos , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Raízes de Plantas/metabolismo , Gravidez , Sementes/metabolismoRESUMO
Smoke water and distillation liquid were used to treat the seeds of Trichosathes kirilowii and to study the effects of smoke water and distillation liquid on the seed germination and seedling growth of T. kirilowii. The results showed that germination rate, germination index and germination vigor of T. kirilowii all were significantly improved with the treatment of SW and DL treatment. The activity of α-amylase were significantly increased with the treatment of SW and DL at 1:2,000. SW and DL treatment showed no significant effects on the activity of SOD. The activity of POD were markedly enhanced under the treatment of SW (1:000) and DL (1:2,000). CAT activity were increased with the treatment of SW and DL at 1:2,000 while were inhibited by SW and DL at 1:500. Seedling height and root length were increased with the treatment of SW and DL (1:1,000, 1:2,000). SW and DL treaments improved the content of chlorophyll, and moreover with the concentration of SW and DL, the stimulatory were also increased. This work demonstrated that smoke water and diatillation liquid at 1:2,000 could stimulate the seed germination and seedling growth of T. kirilowii, and it provided the references for the study of seed germination technology.
Assuntos
Agricultura/métodos , Sementes/crescimento & desenvolvimento , Fumaça/análise , Trichosanthes/metabolismo , Agricultura/instrumentação , Destilação , Germinação , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/metabolismo , Trichosanthes/crescimento & desenvolvimento , Água/química , Água/metabolismoRESUMO
Trichosanthes kirilowii has been widely cultivated as its medicinal use, health care and food value. Drought resistance of seedlings is an important feature in breeding. Seeds of two T. kirilowii strains were used to research the difference of surface ultrastructure characteristic and drought resistance. Scanning electron microscope was used to identify the surface ultrastructure characteristic of seeds and PEG was used to simulate drought stress. The seeds germination rate, MDA content, chlorophyll content and the antioxidant enzymes activity were measured under the drought stress. The results showed that the seed surface colour of KXY-001 was lighter than that of KXY-005. The testa cobwebbing of KXY-001 was more intensive than that of KXY-005. The germination rate of KXY-001 was higher than that of KXY-005 under drought stress. The MDA content was increased and the chlorophyll content was decreased with the increasing of drought degree. The SOD activity of KXY-001 was higher than that of KXY-005, while the activity of POD and CAT was also increased firstly and decreased later. Surface reticulate of seeds and hilar traits can be used as identification points to identify the investigated strains. SOD and POD are activated to resist drought in T. kirilowii seedlings and the drought resistance of KXY-001 is superior than that of KXY-005.
Assuntos
Secas , Plântula/metabolismo , Sementes/metabolismo , Trichosanthes/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Catalase/metabolismo , Clorofila/metabolismo , Germinação , Malondialdeído/metabolismo , Microscopia Eletrônica de Varredura , Peroxidase/metabolismo , Polietilenoglicóis/farmacologia , Sementes/crescimento & desenvolvimento , Sementes/ultraestrutura , Especificidade da Espécie , Superóxido Dismutase/metabolismo , Trichosanthes/classificação , Trichosanthes/crescimento & desenvolvimentoRESUMO
The present study was conducted to determine whether aerial parts of Trichosanthes cucumerina extracts can exert significant antioxidant activity. The antioxidant activity of a hot water extract (HWE) and a cold ethanolic extract (CE) of T. cucumerina aerial parts was evaluated by assessing its (a) radical scavenging ability and prevention effect of lipid peroxidation in vitro, and (b) effects on lipid peroxidation and antioxidant enzyme activities, in vivo.In vitro antioxidant assays (DPPH, TBARS and carotene-linoleic acid assays) clearly demonstrated the antioxidant potential of HWE and CEE. Moreover, HWE increased SOD: by 91.2% and GPX by 104.4% while CEE increased SOD: by 115.5% and GPX by 96.4%) in CCl4-induced rats. Treatments with HWE and CE prevented the accumulation of lipid peroxidation products by 30.5% and 33.8%, respectively, in liver tissues compared to the rats exposed only to CCl4. In conclusion, the present investigation demonstrates for the first time that components in T. cucumerina aerial parts can exert significant antioxidant activity in vivo and in vitro.
Assuntos
Antioxidantes/metabolismo , Trichosanthes/metabolismo , Animais , Antioxidantes/química , Compostos de Bifenilo/química , Temperatura Baixa , Relação Dose-Resposta a Droga , Etanol/química , Feminino , Glutationa Peroxidase/metabolismo , Técnicas In Vitro , Ácido Linoleico/química , Peroxidação de Lipídeos , Masculino , Picratos/química , Ratos , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/químicaRESUMO
Ribosome inactivating proteins (RIPs) are toxic RNA N-glycosidases that cleave an adenine-ribose glycosidic bond at position adenine(4324) with the conserved ricin/α-sarcin loop in the eukaryotic 28S ribosomal RNA. RIPs have captured the attention of botanists, biochemists, and drug discoverers, due to their diverse potent defensive activities, and inter alia, their antitumor and anti-HIV activities. Out of the 145 families of plants, Trichosanthes ranks among the top 5 genera with a good potential of use for discovery of anticancer drugs. Trichosanthin (TCS) is a famous type I RIP purified from T. kirilowii that has been known for around 30 years. Based on the results of voluminous in vitro and in vivo investigations, TCS is considered a good candidate for the treatment of HIV/AIDS and neoplasms. Here we integrate recent progress of the research on the different medicinal activities of TCS. In addition to TCS, other promising RIPs from the same species (such as TAP29 and trichoanguin), and from the same genus Trichosanthes are included. This review presents a brief panorama of the studies on Trichosanthes RIPs. Regarding the debilitating nature of AIDS and different tumors, further understanding of these multifunctional proteins is worthwhile since it may help to open a novel therapeutic window for these stubborn diseases.
Assuntos
HIV-1/efeitos dos fármacos , Proteínas de Plantas/farmacologia , Trichosanthes/metabolismo , Tricosantina/farmacologia , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Infecções por HIV/tratamento farmacológico , Humanos , Neoplasias/tratamento farmacológico , Proteínas de Plantas/uso terapêutico , Plantas Medicinais/metabolismo , Tricosantina/uso terapêuticoRESUMO
The gene encoding Trichosanthes kirilowii defensin (TDEF1) was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR). The newly discovered TDEF1 cDNA contains 231 bp (Genbank accession number DQ526373) and encodes a 76-amino acid protein, which consists of a 29-amino acid signal peptide and a 47-amino acid mature peptide. The partial cDNA, corresponding to the mature peptide coding region of TDEF1, was inserted into bacterial expression vector pET32a(+). Subsequent expression showed that TDEF1 was produced as a 26-kDa fusion protein in the form of inclusion body in Escherichia coli BL21 (DE3). After protein refolding and purification, the fusion TDEF1 displayed an inhibitive activity against the fungal pathogen, Fusarium oxysporum, with EC(50) of 247 microg/ml by means of fungal growth inhibition method.
Assuntos
Antifúngicos/farmacologia , Defensinas/genética , Defensinas/metabolismo , Escherichia coli/metabolismo , Folhas de Planta/genética , Proteínas Recombinantes de Fusão/metabolismo , Trichosanthes/genética , Sequência de Bases , Defensinas/química , Escherichia coli/genética , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Folhas de Planta/química , Folhas de Planta/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Análise de Sequência de DNA , Trichosanthes/química , Trichosanthes/metabolismoRESUMO
Trichosanthin (TCS) from Trichosanthes kirilowii Maximowicz (T. kirilowii) can be used to treat choriocarcinoma. In this work, we established a novel system to produce TCS in crown gall tissues of T. kirilowii infected by Agrobacterium tumefaciens C58 (A. tumefaciens). In the crown gall tissues, a nopaline synthase (NOS) gene of A. tumefaciens was identified by polymerase chain reaction (PCR), and nopaline accumulation was confirmed by a high-voltage filter paper electrophoresis. Furthermore, we optimized conditions to culture the crown gall tissues able to grow fast and produce TCS in an auxin-free medium, and found that a fungal elicitor of Armillaria mellea was capable of stimulation of TCS secretion into the medium. Moreover, we identified that the TCS purified from the crown gall tissues could induce gastric cancer cell death. These data underscore the usefulness of our system as an inexpensive and virtually unlimited source of TCS.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Tumores de Planta/genética , Trichosanthes/metabolismo , Tricosantina/biossíntese , Agrobacterium tumefaciens/genética , Aminoácido Oxirredutases/genética , Antineoplásicos Fitogênicos/isolamento & purificação , Basidiomycota/genética , Reatores Biológicos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Tumores de Planta/microbiologia , Trichosanthes/crescimento & desenvolvimento , Tricosantina/isolamento & purificação , Tricosantina/farmacologiaRESUMO
Trichosanthin is a type I ribosome-inactivating protein with many pharmacological activities. The trichosanthin-coupled Sepharose affinity purification revealed a protein, which was identified by mass spectrometry as the ribosomal protein L10a. The interaction between trichosanthin and recombinant L10a was further confirmed by in vitro binding assay. Kinetic analysis by surface plasmon resonance technology revealed that L10a had a high affinity to trichosanthin with a K(D) of 7.78nM. The study with mutated forms of trichosanthin demonstrated that this specific association correlates with the ribosome-inactivating activity of trichosanthin. This finding might provide insight into the mechanisms by which trichosanthin inactivates ribosome and that underlies its pharmacological effect.
Assuntos
Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Tricosantina/metabolismo , Cromatografia de Afinidade , Proteína Ribossômica L10 , Proteínas Ribossômicas/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Ressonância de Plasmônio de Superfície , Trichosanthes/metabolismoRESUMO
A new galactose-specific lectin has been purified from the extracts of Trichosanthes dioica seeds by affinity chromatography on cross-linked guar gum. The purified lectin (T. dioica seed lectin, TDSL) moved as a single symmetrical peak on gel filtration on Superose-12 in the presence of 0.1 M lactose with an M(r) of 55 kDa. In the absence of ligand, the movement was retarded, indicating a possible interaction of the lectin with the column matrix. In SDS-PAGE, in the presence of beta-mercaptoethanol, two non-identical bands of M(r) 24 and 37 kDa were observed, whereas in the absence of beta-mercaptoethanol, the lectin yielded a single band corresponding to approximately 55,000 Da, indicating that the two subunits of TDSL are connected by one or more disulfide bridges. TDSL is a glycoprotein with about 4.9% covalently bound neutral sugar. Analysis of near-UV CD spectrum by three different methods (CDSSTR, CONTINLL, and SELCON3) shows that TDSL contains 13.3% alpha-helix, 36.7% beta-sheet, 19.4% beta-turns, and 31.6% unordered structure. Among a battery of sugars investigated, TDSL was inhibited strongly by beta-d-galactopyranosides, with 4-methylumbelliferyl-beta-d-galactopyranoside being the best ligand. Chemical modification studies indicate that tyrosine residues are important for the carbohydrate-binding and hemagglutinating activities of the lectin. A partial protection was observed when the tyrosine modification was performed in the presence of 0.2 M lactose. The tryptophan residues of TDSL appear to be buried in the protein interior as they could not be modified under native conditions, whereas upon denaturation with 8 M urea two Trp residues could be selectively modified by N-bromosuccinimide. The subunit composition and size, secondary structure, and sugar specificity of this lectin are similar to those of type-2 ribosome inactivating proteins, suggesting that TDSL may belong to this protein family.
Assuntos
Antígenos Glicosídicos Associados a Tumores/química , Galactose/química , Lectinas de Plantas/química , Sementes/metabolismo , Trichosanthes/metabolismo , Substituição de Aminoácidos , Sítios de Ligação , Configuração de Carboidratos , Carboidratos/química , Dimerização , Dissacarídeos/química , Substâncias Macromoleculares/química , Peso Molecular , Lectinas de Plantas/análise , Lectinas de Plantas/isolamento & purificação , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Especificidade da Espécie , Relação Estrutura-Atividade , Especificidade por Substrato , Trichosanthes/classificaçãoRESUMO
Physicochemical and saccharide-binding studies have been performed on Trichosanthes cucumerina seed lectin (TCSL). The agglutination activity of TCSL is highest in the pH range 8.0-11.0, whereas below pH 7.0 it decreases quite rapidly, which is consistent with the involvement of imidazole side chains of His residues, which titrate in this pH range, in the sugar-binding activity of the lectin. The lectin activity is unaffected between 0 and 60 degrees C, but a sharp decline occurs at higher temperatures. Isoelectric focusing studies show that TCSL has three isoforms with pI values of 5.3, 6.2, and 7.1, with the isoform of pI 6.2 being the most abundant. Circular dichroism spectroscopic studies reveal that TCSL contains about 28.4% beta-sheet, 10.6% beta-turns, 7% polyproline type 2 structure, with the remainder comprising unordered structure; the alpha-helix content is negligible. Binding of 4-methylumbelliferyl-beta-D-galactopyranoside (MeUmbbetaGal) to TCSL results in a significant increase in the fluorescence intensity of the ligand, and this change has been used to obtain the association constant for the interaction. At 25 degrees C, the association constant, K(a), for the TCSL-MeUmbbetaGal interaction was determined as 6.9 x 10(4)M(-1). Binding of nonfluorescent, inhibitory sugars was studied by monitoring their ability to reverse the fluorescence changes observed when MeUmbbetaGal was titrated with TCSL.
Assuntos
Himecromona/análogos & derivados , Lectinas de Plantas/química , Lectinas de Plantas/metabolismo , Trichosanthes/metabolismo , Metabolismo dos Carboidratos , Fenômenos Químicos , Físico-Química , Dicroísmo Circular , Estabilidade de Medicamentos , Galactose/metabolismo , Glicosídeos/metabolismo , Concentração de Íons de Hidrogênio , Himecromona/metabolismo , Cinética , Ligantes , Estrutura Secundária de Proteína , Sementes/metabolismo , TemperaturaRESUMO
OBJECTIVE: To establish a hairy root culture system by double transformation for Trichosanthes kirilowii. METHOD: 1. Crown galls were induced by direct infection of sterile seedlings of T. kirilonii with Agrobacterium tumefaciens C58, and then the hairy roots were obtained from the regenerated plants by infection with A. rhzogenes 15834; 2. Transformation of Ti and Ri plasmids was inspected by high-pressure-paper electrophoresis; 3. The protein contents in the tissues of T. kirilowii were inspected by spectrophotometer and SDS-PAGE. RESULT: A hairy root culture system has been established successfully by double transformation with Ti and Ri plasmids in T. kirilowii. CONCLUSION: Compared with the ordinary hairy roots, the double transformed hairy roots grow faster but retain similar protein contents.