Gene losses and partial deletion of small single-copy regions of the chloroplast genomes of two hemiparasitic Taxillus species.[Pubmed: 29026168]

Numerous variations are known to occur in the chloroplast genomes of parasitic plants. We determined the complete chloroplast genome sequences of two hemiparasitic species, Taxillus chinensis and T. sutchuenensis, using Illumina and PacBio sequencing technologies. These species are the first members of the family Loranthaceae to be sequenced. The complete chloroplast genomes of T. chinensis and T. sutchuenensis comprise circular 121,363 and 122,562 bp-long molecules with quadripartite structures, respectively. Compared with the chloroplast genomes of Nicotiana tabacum and Osyris alba, all ndh genes as well as three ribosomal protein genes, seven tRNA genes, four ycf genes, and the infA gene of these two species have been lost. The results of the maximum likelihood and neighbor-joining phylogenetic trees strongly support the theory that Loranthaceae and Viscaceae are monophyletic clades. This research reveals the effect of a parasitic lifestyle on the chloroplast structure and genome content of T. chinensis and T. sutchuenensis, and enhances our understanding of the discrepancies in terms of assembly results between Illumina and PacBio.

Transcriptome Analysis of Taxillusi chinensis (DC.) Danser Seeds in Response to Water Loss.[Pubmed: 28046012]

Taxillus chinensis (DC.) Danser, the official species of parasitic loranthus that grows by parasitizing other plants, is used in various traditional Chinese medicine prescriptions. ABA-dependent and ABA-independent pathways are two major pathways in response to drought stress for plants and some genes have been reported to play a key role during the dehydration including dehydration-responsive protein RD22, late embryogenesis abundant (LEA) proteins, and various transcription factors (TFs) like MYB and WRKY. However, genes responding to dehydration are still unknown in loranthus.

Immunomodulatory activities of polysaccharides isolated from Taxillus chinensis and Uncaria rhyncophylla.[Pubmed: 24053827]

Taxillus chinensis and Uncaria rhyncophylla are the herbs used in traditional Chinese anticancer formulations. During the past decade, research on plant polysaccharides has gained importance due to their therapeutic value and minimum side effects. In this study, hot water extraction method was employed to isolate polysaccharides from the stems of T. chinensis and stems with hooks of U. rhyncophylla. Size-exclusion chromatography was then used for further fractionation. Separated fractions from T. chinensis were designated as TCP-1, TCP-2 and TCP-3 and those from U. rhyncophylla were termed UC-1 and UC-2. Their sugar compositions were estimated using gas chromatography that revealed the presence fructose, glucose, xylose, arbinose, and rhamnose. Amino acid analysis of these fractions has indicated that they are protein-bound polysaccharides. The antioxidant activities were investigated using DPPH and yeast assays. The ability of these polysaccharide fractions to stimulate mouse macrophages was measured using Griess reagent and ELISA test. The results revealed that some of the isolated fractions (TCP-2, TCP-3, UC-1 and UC-2) displayed significant antioxidant activities and were also found to be effective immunomodulators in a concentration-dependent manner. Outcomes of this research strongly indicate that U. rhyncophylla and T. chinensis have therapeutic potential to be used for the treatment of cancer.

Four new hemiterpenoid derivatives from Taxillus chinensis.[Pubmed: 23376411]

Four new hemiterpenoid derivatives, taxilluside A-D (1-4), were isolated from the branches and leaves of Taxillus chinensis (DC.) Danser. Their structures were determined on the basis of spectroscopic analysis. Of these compounds, compounds 3 and 4 showed inhibition activity on Calcium concentration in myocardial cells evaluated by measuring the changes of fluorescence signal using Laser scanning confocal microscope.

Antioxidant and anti-inflammatory activities of selected medicinal plants containing phenolic and flavonoid compounds.[Pubmed: 22023309]

The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using Saccharomyces cerevisiae , whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely, Scutellaria baicalensis , Taxillus chinensis , Rheum officinale , and Sophora japonica , showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica, Mahonia fortunei , and Sophora flavescens ) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC(50) values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.

Traditional Chinese medicine herbal extracts of Cibotium barometz, Gentiana scabra, Dioscorea batatas, Cassia tora, and Taxillus chinensis inhibit SARS-CoV replication.[Pubmed: 24716104]

Development of anti-severe acute respiratory syndrome associated coronavirus (SARS-CoV) agents is pivotal to prevent the reemergence of the life-threatening disease, SARS. In this study, more than 200 extracts from Chinese medicinal herbs were evaluated for anti-SARS-CoV activities using a cell-based assay that measured SARS-CoV-induced cytopathogenic effect (CPE) in vitro on Vero E6 cells. Six herbal extracts, one each from Gentianae Radix ( lóng dǎn; the dried rhizome of Gentiana scabra), Dioscoreae Rhizoma ( shān yào; the tuber of Dioscorea batatas), Cassiae Semen ( jué míng zǐ; the dried seed of Cassia tora) and Loranthi Ramus ( sāng jì shēng; the dried stem, with leaf of Taxillus chinensis) (designated as GSH, DBM, CTH and TCH, respectively), and two from Rhizoma Cibotii ( gǒu jǐ; the dried rhizome of Cibotium barometz) (designated as CBE and CBM), were found to be potent inhibitors of SARS-CoV at concentrations between 25 and 200 μg/ml. The concentrations of the six extracts needed to inhibit 50% of Vero E6 cell proliferation (CC50) and 50% of viral replication (EC50) were determined. The resulting selective index values (SI = CC50/EC50) of the most effective extracts CBE, GSH, DBM, CTH and TCH were > 59.4, > 57.5, > 62.1, > 59.4, and > 92.9, respectively. Among these extracts, CBM and DBM also showed significant inhibition of SARS-CoV 3CL protease activity with IC50 values of 39 μg/ml and 44 μg/ml, respectively. Our findings suggest that these six herbal extracts may have potential as candidates for future development of anti-SARS therapeutics.AbbreviationsSARS,severe acute respiratory syndromeCoV,coronavirusCPE,cytopathogenic effectTCM,traditional Chinese medicine.

Parasitic loranthus from Loranthaceae rather than Viscaceae potently inhibits fatty acid synthase and reduces body weight in mice.[Pubmed: 18583073]

Our previous results have shown one species of parasitic loranthus (Taxillus chinensis (DC.) Dancer) exhibits potent inhibition on fatty acid synthase (FAS) that is proposed to be a potential therapeutic target for treatment of obesity. However, the medicinal parasitic loranthus come from tens of plants of two families, the Loranthaceae and the Viscaceae. This study was carried out to figure out whether these parasitic loranthus from the two families have similar inhibitory ability on FAS, and whether the parasitic loranthus with potent inhibitory ability on FAS significantly reduce body weight of animal.

Potent inhibition of fatty acid synthase by parasitic loranthus [Taxillus chinensis (dc.) danser] and its constituent avicularin.[Pubmed: 16570511]

The medicinal herb parasitic loranthus in a screen was found to inhibit fatty acid synthase (EC 2.3.1.85, FAS) and reduce body weight of rats in our previous study. Now we have determined the inhibitory characteristics and kinetic parameters of extracts of parasitic loranthus [Taxillus chinensis (DC.) Danser]. The parasitic loranthus extracts (PLE) inhibits FAS reversibly and irreversibly and with an IC50 value of 0.48 microg/ml, appears to be the most potent inhibitor reported to date. PLE contains various potent inhibitors and may react with different sites on FAS. The irreversible inhibition exhibits a time-dependent biphasic process including a speedy fast-phase during the initial several minutes. The fast-phase inhibition seems to be caused by some potent but low-concentration component(s) in the extracts. In addition, we have found that avicularin existing in this herb can potently inhibit FAS. This glycosylated flavonoid and quercetin play an effective role in inhibiting FAS by parasitic loranthus.