Chinese dragon's blood ethyl acetate extract suppresses gastric cancer progression through induction of apoptosis and autophagy mediated by activation of MAPK and downregulation of the mTOR-Beclin1 signalling cascade.

Gastric cancer (GC) is a malignancy with high morbidity and mortality. Chinese dragon's blood is a traditional Chinese medicine derived from the red resin of Dracaena cochinchinensis (Lour.) S. C. Chen. However, the antigastric cancer effect of Chinese dragon's blood has not yet been reported. Herein, we demonstrated that Chinese dragon's blood ethyl acetate extract (CDBEE) suppressed the proliferative and metastatic potential of human gastric cancer MGC-803 and HGC-27 cells. CDBEE suppressed epithelial-mesenchymal transition in MGC-803 and HGC-27 cells. Moreover, CDBEE induced apoptotic and autophagic cell death in MGC-803 and HGC-27 cells. The cytotoxicity of CDBEE in human gastric epithelial GES-1 cells was dramatically weaker than that in human gastric cancer cells. Mechanistically, the activation of the mitogen-activated protein kinase (MAPK) signalling pathway was involved in the growth inhibition of MGC-803 and HGC-27 cells by CDBEE. Additionally, CDBEE-induced autophagic cell death was mediated by downregulation of the mammalian target of rapamycin (mTOR)-Beclin1 signalling cascade and upregulation of the ATG3/ATG7-LC3 signalling cascade. Importantly, CDBEE exhibited potent anti-GC efficacy in vivo without obvious toxicity or side effects. Therefore, CDBEE may be a promising candidate drug for the treatment of gastric cancer, especially for GC patients with aberrant MAPK signalling or mTOR signalling.

Structures and Bioactivities of Steroidal Saponins Isolated from the Genera Dracaena and Sansevieria.

The species Dracaena and Sansevieria, that are well-known for different uses in traditional medicines and as indoor ornamental plants with air purifying property, are rich sources of bioactive secondary metabolites. In fact, a wide variety of phytochemical constituents have been isolated so far from about seventeen species. This paper has reviewed the literature of about 180 steroidal saponins, isolated from Dracaena and Sansevieria species, as a basis for further studies. Saponins are among the most characteristic metabolites isolated from the two genera. They show a great variety in structural motifs and a wide range of biological activities, including anti-inflammatory, anti-microbial, anti-proliferative effects and, in most case, remarkable cytotoxic properties.

Optimization of Cadmium (CD(2+)) removal from aqueous solutions by novel biosorbent.

In this research, dead leaves of a common ornamental plant, Dracaena draca known also as dragon tree was used as a biosorbent for the removal of Cadmium (Cd(2+)) from aqueous solutions using a full 2(3) factorial experimental design. Three factors were investigated at two different levels, metal ion concentration (X = 10 and 100 ppm), hydrogen ion concentration (Ph = 2 and 7) and biomass dose (BD = 0.1 and 0.5g). Experiments were carried out in duplicates with 50 ml of Cd(2+) solutions at room temperature. When comparing observed values (experimental) with calculated values (model), they were set closely together that allowed suggesting a normal distribution where (R(2) = 0.9938). A characterization of the biosorbent was done by pHzpc and SEM-EDAX. Results also showed that the most significant effect for Cd(2+) biosorption was ascribed to (X). The interaction effects of (pH BD) and (X pH) were found to have significant influence on Cd(2+) removal efficiency. The highest Cd(2+) removal percentage attained by 79.60% at X = 10 ppm, pH = 7 and BD = 0.5g. The reusability of the biosorbent was tested in three desorption cycles and the regeneration efficiency was above 99.7%.

Flavonoids produced by tissue culture of Dracaena cambodiana.

Dragon's blood is a traditional medicine used in many countries of many cultures because of its various therapeutic uses, and its main bioactive compounds are flavonoids, which mainly exhibit antitumor and antimicrobial activities. In the process of tissue culture of Dracaena cambodiana, one of its resource plants, red secretion was discovered in the culture when 6-benzylaminopurine was added. Analysis of its constituents by HPLC in comparison with dragon's blood and the standards proved that 17 compounds, including 10 flavonoids, are the same as those in dragon's blood. It is promising that flavonoids from dragon's blood could be produced by tissue culture of its resource plants for the development of new drugs.

Cloning, bioinformatics and the enzyme activity analyses of a phenylalanine ammonia-lyase gene involved in dragon's blood biosynthesis in Dracaena cambodiana.

Phenylalanine ammonia-lyase (PAL) is the key enzyme of the phenylpropanoid pathway, playing an important role in plant development and defence. We cloned a partial cDNA of PAL gene, DcPAL1, from Dracaena cambodiana seedlings using RT-PCR with degenerate primers that were designed based on a multiple sequence alignment of known PAL genes from other plant species. DcPAL1 shows highly homologous to other known PAL genes registered in GenBank, being closest to that of Musa acuminata. DcPAL1 has a relatively high GC content and most of the GC is in the third codon position. It has 768 bp in size with a maximum open reading frame (ORF) of 765 bp, encoding a 255 amino acid-polypeptide. The deduced PAL protein is a stable protein, having classical PAL domains and consisting of three major hydrophobic domains. Analysis of effective number of codons (ENC) shows that DcPAL1 codons are used at equal frequency. Relatively higher usage frequency appears randomly in codons ended with any of the four bases; six codons have no usage bias. There are 45 codons showing distinct usage preference between DcPAL1 and E. coli, 20 between DcPAL1 and yeast. Therefore, the yeast system may be more suitable for the expression of DcPAL1. Upon the elicitation of Fusarium proliferatum, a potent elicitor of dragon's blood, the PAL enzyme activity in the leaves and stems of D. cambodiana and other two Dracaena spp. significantly increased, accompanying with the formation of dragon's blood, indicating the involvement of PAL in the biosynthesis of dragon's blood, a precious traditional medicine.