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At least 19 recordsLinked to original sources
PubMed2006

Phenanthroquinolizidine alkaloids from the roots of Boehmeria pannosa potently inhibit hypoxia-inducible factor-1 in AGS human gastric cancer cells.

A bioassay-guided phytochemical investigation on the methanol extract of Boehmeria pannosa, using a HIF-1-mediated reporter gene assay, led to the isolation of two phenanthroquinolizidine alkaloids, (-)-cryptopleurine (1) and (-)-(15R)-hydroxycryptopleurine (2). The structure of the new compound 2 was determined by spectroscopic methods. Compounds 1 and 2 potently inhibited the hypoxia-induced expression of a reporter gene under the control of a hypoxia response element (HRE) with IC(50) values of 8.7 and 48.1 nM, respectively. Furthermore, 1 and 2 suppressed the accumulation of HIF-1alpha protein in a dose-dependent manner, but not the HIF-1beta protein and inhibited expression of vascular endothelial growth factor (VEGF) by hypoxia.

Alkaloids↗
PubMed2003

Cytotoxic alkaloids from Boehmeria siamensis.

Two new phenanthroquinolizidine alkaloids, boehmeriasins A and B, were isolated from the aqueous ethanolic extract of Boehmeria siamensis Craib (Urticaceae) by bioassay-guided fractionation. Their structures were elucidated on the basis of spectral evidence. Boehmeriasin A possesses cytotoxic activity against 12 cell lines from 6 panels of cancer including lung cancer, colon cancer, breast cancer, prostate cancer, kidney cancer and leukemia with GI (50) between 0.2 and 100 ng/mL, whereas boehmeriasin B showed lower activity.

Alkaloids↗
PubMed2006

Inhibition of hepatitis B virus production by Boehmeria nivea root extract in HepG2 2.2.15 cells.

AIM: To explore the anti-hepatitis B virus (HBV) effects of Boehmeria nivea (B. nivea) root extract (BNE) by using the HepG2 2.2.15 cell model system. METHODS: Hepatitis B surface antigen (HBsAg), hepatitis B virus e antigen (HBeAg), and HBV DNA were measured by using ELISA and real-time PCR, respectively. Viral DNA replication and RNA expression were determined by using Southern and Northern blot, respectively. RESULTS: In HepG2 2.2.15 cells, HBeAg (60%, P < 0.01) and particle-associated HBV DNA (> 99%, P < 0.01) secretion into supernatant were significantly inhibited by BNE at a dose of 100 mg/L, whereas the HBsAg was not inhibited. With different doses of BNE, the reduced HBeAg was correlated with the inhibition of HBV DNA. The anti-HBV effect of BNE was not caused by its cytotoxicity to cells or inhibition of viral DNA replication and RNA expression. CONCLUSION: BNE could effectively reduce the HBV production and its anti-HBV machinery might differ from the nucleoside analogues.

Antiviral Agents↗
PubMed1998

Evaluation of the hepatoprotective and antioxidant activity of Boehmeria nivea var. nivea and B. nivea var. tenacissima.

In this study, the relationship between liver protective effects and antioxidant activity of Boehmeria nivea var. nivea (= B. nivea) and B. nivea var. tenacissima (= B. frutescens) was investigated. The water extracts of both plants exhibited a hepatoprotective activity against CCl4-induced liver injury. B. nivea var. nivea and B. nivea var. tenacissima, also showed anti-oxidant effects in FeCl2-ascorbate induced lipid peroxidation in rat liver homogenate. Moreover, the active oxygen species scavenging potencies were evaluated by an electron spin resonance (ESR) spin-trapping technique. B. nivea var. tenacissima displayed better superoxide radical scavenging activity than B. nivea. Based on these findings, we suggest that in the liver protective and antioxidative effects of B. nivea var. nivea and B. nivea var. tenacissima, possibly involve mechanisms related to free radical scavenging effects.

Animals↗
PubMed2000

Steroid 5alpha-reductase inhibitory activity and hair regrowth effects of an extract from Boehmeria nipononivea.

The acetone extract of Boehmeria nipononivea showed both potent 5alpha-reductase inhibitory activity and hair regrowth promotion effects on mice. 5alpha-Reductase inhibitory activity-guided fractionation led to six active fatty acids: alpha-linolenic, linoleic, palmitic, elaidic, oleic and stearic acids. The extract of B. nipononivea, and alphalinolenic, elaidic and stearic acids exhibited a hair regrowth effect.

5-alpha Reductase Inhibitors↗
PubMed1993

Ramie (Boehmeria nivea) pollen-induced bronchial asthma and allergenic cross-reactivity of ramie and Parietaria.

Ramie (Boehmeria nivea), a plant of the Urticaceae family, is widely distributed in the Nagasaki area, and has been established to be a cause of asthma. The rate of positive reactions to ramie in intradermal tests was 11.7% among adult asthmatic patients in the Nagasaki area. In this study, 10 patients were positive in provocation tests using ramie pollen. Ramie pollen-specific IgE antibodies were measured by ELISA, with the positive provocation test group showing higher O.D. values than the positive intradermal test group (p < 0.05). Ramie is of the same family as Parietaria, an important allergen in Europe. The cross-reactivity of ramie and Parietaria was examined by an ELISA inhibition test using P. officinalis and P. judaica (Pj10), but no cross-reactivity was found, suggesting that ramie may be a new independent allergen. As ramie is widely distributed throughout Japan and South-east Asia, further study is needed to determine whether it is an important allergen of the Urticaceae family in this region, as is Parietaria in Europe, and Urtica in America.

Adolescent↗
PubMed1997

A synopsis of the occurrence and pathogenicity of Phytophthora species in mainland China.

To date, 26 species of Phytophthora have been reported in mainland China but only 23 are accepted as good taxa. Phytophthora nicotianae (P. parasitica) is the single most important species causing over 40 different plant diseases; P. boehmeriae is widespread attacking Gossypium, Boehmeria, Citrus, Broussonetia papyrifera and Pterocarya stenoptera; P. "fragariae var. oryzo-bladis" is unique to mainland China causing blight of Oryza sativa seedlings; P. megasperma sensu lato has been isolated from Glycine max, Asparagus officinalis and Spinacia oleracea. In Hainan Province, P. heveae is present in the soil without causing apparent diseases to Hevea brasiliensis there.

Journal Article↗
PubMed2005

A marked enhancement in the production of a highly alkaline and thermostable pectinase by Bacillus pumilus dcsr1 in submerged fermentation by using statistical methods.

The production of a highly alkaline and thermostable pectinase of Bacillus pumilus was optimized in submerged fermentation using Plackett-Burman design and response surface methodology. Three fermentation variables (C:N ratio, K(2)HPO(4), and pH), which were identified to significantly affect pectinase production by Plackett-Burman design were further optimized using response surface methodology of central composite design (CCD). An over all 34- and 41-fold increase in enzyme production was achieved in shake flasks and lab fermenter by the optimization of variables using statistical approaches, respectively. The enzyme was optimally active at pH 10.5 and 50 degrees C, and selectively degraded only the noncellulosic gummy material of ramie (Boehmeria nivea) fibres causing 10.96% fibre weight loss, and therefore, the enzyme could find application in fibre processing industry. The use of the enzyme in fibre processing reduces the use of alkali, and the associated alkalinization of water bodies.

Bacillus↗
PubMedDate not supplied

Induction of G1 arrest and differentiation in MDA-MB-231 breast cancer cell by boehmeriasin A, a novel compound from plant.

Boehmeriasin A is a new phenanthroquinolizidine alkaloid recently isolated from the Boehmeria siamensis Craib (Urticaceae). In vitro biological activity assay demonstrated that this novel compound has wide-range, strong antitumor activity. This study is aimed to determine the effects of boehmeriasin A on breast cancer cell (MDA-MB-231 cell line). Proliferation assay and fluorescence activated cell sorter (FACS) showed that cell growth inhibition and G1 phase arrest of cell cycle were caused by boehmeriasin A. The concentrations resulting in total and 50% growth inhibition are 0.007 and 0.0035 microg/mL, respectively. Exposed in 0.007 microg/mL boehmeriasin A for 12 h, the G1 phase cell percent increased from 44.8% pre-drug treatment to 66.3%. Consistent with G1 arrest and cell growth inhibition, cyclin E2 and cyclin D1 messenger RNA expression in the cell was down-regulated with drug treatment. Then, few apoptotic cells were detected, and most other cells underwent differentiation, which is characterized by specific changes in cell morphology, lots of lipid droplet accumulation, and increasing expression of adipocyte differentiation-related protein. The result first demonstrates that boehmeriasin A potently inhibits the proliferation of breast cancer cell MDA-MB-231 via the G1 phase cell cycle arrest and differentiation induction, and as such, may be considered as candidate chemotherapeutic and/or chemopreventive agent for breast cancer.

Apoptosis↗
PubMed2026

Expression of cotton GhMYB109 complements non-hair cell fate in the root epidermis of the Arabidopsis thaliana werewolf mutant.

Root cell fate and patterning in plants are orchestrated by the expression of cell-type-specific genes, including WEREWOLF (WER). Phylogenetic analysis of WER, functional WER homologs in Type III species (Rhodiola rosea and Boehmeria nivea), and related R2R3 MYB proteins identified in the cotton genome revealed that GhMYB109-a known regulator of fiber development in cotton ovules-clustered in a clade with Arabidopsis thaliana WER. To determine whether GhMYB109 is a functional homolog of WER, we expressed GhMYB109 under the control of the CaMV 35S promoter in the Arabidopsis thaliana wer-1 mutant and analyzed root epidermal cell patterning by counting root hairs. GhMYB109 expression significantly decreased the percentage of root hairs at both H and N positions. We found that most epidermal cells in the cotton root develop into root hairs (Type I pattern) although the cotton genome contains a functional WER homolog, GhMYB109. Additionally, GhMYB109 has been reported not to be expressed in cotton roots. These support the idea that GhMYB109 is a functional homolog of WER and that Arabidopsis thaliana and cotton diverged in root epidermal morphology through modifications in cis-regulatory elements rather than a functional divergence of their WER-like R2R3 MYB transcription factors.

Arabidopsis thaliana↗
PubMed2000

Enzymatic degumming of ramie bast fibers.

Bast fibers from ramie (Boehmeria nivea) were treated with cell-free culture supernatants from an Amycolata sp. and a recombinant Streptomyces lividans strain expressing the Amycolata pectate lyase to investigate the degumming effects of different extracellular polysaccharide-degrading enzymes. Culture supernatants from the Amycolata sp. with high pectate lyase activities were most effective in fiber separation and reduced the gum content of ramie fibers by 30% within 15 h. Xylanase activity produced by the Amycolata sp. contributed little to the degumming. Electron micrographs showed that the crude pectate lyase from the Amycolata sp. removed plant gum more efficiently from decorticated ramie bast fibers than the purified enzyme. Similarly, degumming with the crude enzyme of the Amycolata sp. and the recombinant S. lividans strain for 24 h resulted in fibers with a residual gum content of 14.7 and 17.3%, respectively. Degumming with the crude enzyme of the recombinant Streptomyces strain was slightly improved by the addition of a commercial pectinesterase. No significant degumming was observed with the crude enzyme from an S. lividans strain that did not produce the Amycolata pectate lyase. These results indicate that the pectinolytic activity of the Amycolata sp. plays an active role in degumming of ramie bast fibers.

Actinomycetales↗
PubMed2003

Single-strand-conformation polymorphism of ribosomal DNA for rapid species differentiation in genus Phytophthora.

Single-strand-conformation polymorphism (SSCP) of ribosomal DNA of 29 species (282 isolates) of Phytophthora was characterized in this study. Phytophthora boehmeriae, Phytophthora botryosa, Phytophthora cactorum, Phytophthora cambivora, Phytophthora capsici, Phytophthora cinnamomi, Phytophthora colocasiae, Phytophthora fragariae, Phytophthora heveae, Phytophthora hibernalis, Phytophthora ilicis, Phytophthora infestans, Phytophthora katsurae, Phytophthora lateralis, Phytophthora meadii, Phytophthora medicaginis, Phytophthora megakarya, Phytophthora nicotianae, Phytophthora palmivora, Phytophthora phaseoli, Phytophthora pseudotsugae, Phytophthora sojae, Phytophthora syringae, and Phytophthora tropicalis each showed a unique SSCP pattern. Phytophthora citricola, Phytophthora citrophthora, Phytophthora cryptogea, Phytophthora drechsleri, and Phytophthora megasperma each had more than one distinct pattern. A single-stranded DNA ladder also was developed, which facilitates comparison of SSCP patterns within and between gels. With a single DNA fingerprint, 277 isolates of Phytophthora recovered from irrigation water and plant tissues in Virginia were all correctly identified into eight species at substantially reduced time, labor, and cost. The SSCP analysis presented in this work will aid in studies on taxonomy, genetics, and ecology of the genus Phytophthora.

DNA, Fungal↗
PubMed1997

Temporal and spatial pattern of expression of the pea phenylalanine ammonia-lyase gene1 promoter in transgenic tobacco.

Genes encoding phenylalanine ammonia-lyase (PAL) form a small multigene family with at least three members in pea. Tissue-specific expression of the promoter of a member of PAL gene family (PSPAL1) was investigated in the transgenic tobacco transformants carrying the different modes of chimeric fusion between the PSPAL1 promoter and a bacterial beta-glucuronidase (GUS) gene. In stems, at least, strict correlation was found between steady-state levels of Gus-mRNA and enzyme activity. Significantly high level of GUS activity was observed in roots, particularly in meristematic tissues and the pigmented region of petals of transgenic tobacco carrying the translational fusion type B (-1,394 to +140 of PSPAL1 connected to Gus), followed by moderately high level of GUS activity carrying the translational fusion type A (-1,394 to +117). GUS expression in tissues of mature leaves, however, was very low in these constructs. Extremely low GUS activity was observed in the transformants of transcriptional fusion type (-1,394 to +5), whilst no activity was detected carrying non-transcription fusion type (-1,394 to -27). Furthermore, the pattern of the PSPAL1 expression was characterized in response to pathogen ingress and woundings in transgenic tobacco carrying the translational fusion type B. Woundings itself triggered marked expression of PSPAL1-driven GUS expression at the wounded sites. Inoculation of nonpathogens, Phytophthora capsici, P. boehmeriae and Erisiphe graminis f. sp. hordei, both caused rapid and very clear GUS expression zone along with the development of hypersensitive cell death area where callose was accumulated, however, the inoculation of a pathogen, P.nicotiana caused slow and hazy GUS expression zone along with the lesion development. These results suggest that the expression of pea PSPAL1 promoter is regulated in a similar fashion, at least in a part, in pea and transgenic tobacco, under the plant development and various environmental cues.

Gene Expression Regulation, Plant↗