1'-Acetoxychavicol acetate as an inhibitor of phagocytosis of macrophages.
(74/85)
We screened extracts of edible plants for inhibitors of phagocytosis by peritoneal exudate macrophages. 1'-Acetoxychavicol acetate was isolated from the ethyl acetate extract of Languas galanga, and this compound strongly inhibited phagocytosis at an IC50 value of 1.2 microM with negligible effects on pinocytosis and cell viability. Target(s) of 1'-acetoxychavicol acetate was suggested to be downstream of the signal transduction pathway that is mediated by protein kinase C. (+info)
Purification of ginger proteases by DEAE-Sepharose and isoelectric focusing.
(75/85)
Ginger proteases in ginger rhizome (Zingiber officinale roscoe) were extracted from the ginger acetone powder and purified on DEAE-Sepharose and Sephadex G-75 columns. Before the purification, excess p-chloromercuribenzoate was added to the enzymes to prevent their autodigestion. The mercuribenzoate-proteases were further purified and fractionated by isoelectric focusing in Ampholine of pH 3-10 or pH 4-6. The proteases were fractionated into three components by the isoelectric focusing, having pI value of 4.5, 4.6 and 4.8 respectively. All these proteases had a molecular mass of 29,000 as measured by SDS-polyacrylamide gel electrophoresis and by TSK G2000SW XL gel chromatography. The Ampholine in the purified enzymes can quickly be removed by the gel chromatography of TSK G2000SW. Some divalent metal ions, such as Hg2+, Cu2+, Cd2+, and Zn2+, strongly inhibited these purified enzymes. (+info)
Inhibition of skin tumorigenesis by rosemary and its constituents carnosol and ursolic acid.
(76/85)
A methanol extract of the leaves of the plant Rosmarinus officinalis L. (rosemary) was evaluated for its effects on tumor initiation and promotion in mouse skin. Application of rosemary to mouse skin inhibited the covalent binding of benzo(a)pyrene [B(a)P] to epidermal DNA and inhibited tumor initiation by B(a)P and 7,12-dimethylbenz[a]anthracene (DMBA). Topical application of 20 nmol B(a)P to the backs of mice once weekly for 10 weeks, followed 1 week later by promotion with 15 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) twice weekly for 21 weeks, resulted in the formation of 7.1 tumors per mouse. In a parallel group of animals that were treated topically with 1.2 or 3.6 mg of rosemary 5 min prior to each application of B(a)P, the number of tumors per mouse was decreased by 54 or 64%, respectively. Application of rosemary to mouse skin also inhibited TPA-induced ornithine decarboxylase activity, TPA-induced inflammation, arachidonic acid-induced inflammation, TPA-induced hyperplasia, and TPA-induced tumor promotion. Mice initiated with 200 nmol DMBA and promoted with 5 nmol TPA twice weekly for 19 weeks developed an average of 17.2 skin tumors per mouse. Treatment of the DMBA-initiated mice with 0.4, 1.2, or 3.6 mg of rosemary together with 5 nmol TPA twice weekly for 19 weeks inhibited the number of TPA-induced skin tumors per mouse by 40, 68, or 99%, respectively. Topical application of carnosol or ursolic acid isolated from rosemary inhibited TPA-induced ear inflammation, ornithine decarboxylase activity, and tumor promotion. Topical application of 1, 3, or 10 mumol carnosol together with 5 nmol TPA twice weekly for 20 weeks to the backs of mice previously initiated with DMBA inhibited the number of skin tumors per mouse by 38, 63, or 78%, respectively. Topical application of 0.1, 0.3, 1, or 2 mumol ursolic acid together with 5 nmol TPA twice weekly for 20 weeks to DMBA-initiated mice inhibited the number of tumors per mouse by 45-61%. (+info)
Analysis of the phylogenetic relationships of strains of Burkholderia solanacearum, Pseudomonas syzygii, and the blood disease bacterium of banana based on 16S rRNA gene sequences.
(77/85)
We determined nearly complete 16S rRNA gene sequences for 19 isolates of Burkholderia solanacearum, three isolates of the blood disease bacterium of bananas, and two isolates of Pseudomonas syzygii, the cause of Sumatra disease of cloves. The dendrogram produced by comparing all of these sequences revealed that there were two divisions, which corresponded to the results obtained previously in a restriction fragment length polymorphism analysis (D. Cook, E. Barlow, and L. Sequeira, Mol. Plant Microbe Interact. 2:113-121, 1989) and a total 16S ribosomal DNA (rDNA) sequence analysis of four isolates representing four biovars of B. solanacearum (X. Li, M. Dorsch, T. Del Dot, L. I. Sly, E. Stackebrandt, and A. C. Hayward, J. Appl. Bacteriol. 74:324-329, 1993). Division 1 comprised biovars 3, 4, and 5 and an aberrant biovar 2 isolate (strain ACH0732), and division 2 included biovars 1, 2, and N2, the blood disease bacterium, and P. syzygii. Specific nucleotides at positions 458 to 460 (UUC) and 474 (A) characterized division 2, whereas in division 1 the nucleotides at these positions were ACU and U, respectively. However, strain ACH0732 had a U at position 458, as did division 2 isolates, and G instead of U at position 474. Division 2 consisted of two subdivisions; one subdivision contained two B. solanacearum isolates that originated from Indonesia, P. syzygii strains, and blood disease bacterium strains, and the other subdivision contained all of the other division 2 isolates. Within division 1, the level of 16S rDNA sequence similarity ranged from 99.8 to 100%, and within division 2, the levels of 16S rDNA sequence similarity ranged from 99.1 to 100%. The division 1 isolates exhibited an average level of 16S rDNA sequence similarity to division 2 isolates of 99.3% (range, 99.1 to 99.5%). The occurrence of consistent polymorphisms in the 16S rDNA sequences of B. solanacearum strains, in particular unique 16S rDNA sequence differences in aberrant biovar 2 isolate ACH0732, and the occurrence of the Indonesian subdivision of division 2 suggest that this group is a rapidly evolving (tachytelic) group. (+info)
Inhibition of tumor promotion in SENCAR mouse skin by ethanol extract of Zingiber officinale rhizome.
(78/85)
There is considerable emphasis on identifying potential chemopreventive agents present in food consumed by the human population. Ginger rhizome (Zingiber officinale), known commonly as ginger, is consumed worldwide in cookeries as a spice and a flavoring agent. In prior in vitro studies, it has been shown that the water or organic solvent extract of ginger possesses antioxidative and antiinflammatory properties. In this study, we evaluated whether ethanol extract of ginger (GE) possesses anti-tumor-promoting effects in a mouse skin tumorigenesis model. Because skin tumor promoters induced epidermal ornithine decarboxylase (ODC), cyclooxygenase, and lipoxygenase activities, and edema and hyperplasia are conventionally used markers of skin tumor promotion, first, we assessed the effect of GE on these parameters. Preapplication of GE onto the skin of SENCAR mice resulted in significant inhibition of 12-0-tetradecanoylphorbol-13-acetate (TPA)-caused induction of epidermal ODC, cyclooxygenase, and lipoxygenase activities and ODC mRNA expression in a does-dependent manner. Preapplication of GE to mouse skin also afforded significant inhibition of TPA-caused epidermal edema (56%) and hyperplasia (44%). In long-term tumor studies, topical application of GE 30 min prior to that of each TPA application to 7,12-dimethylbenz(a)anthracene-initiated SENCAR mice resulted in a highly significant protection against skin tumor incidence and its subsequent multiplicity. The animals pretreated with GE showed substantially lower tumor body burdens compared with non-GE-treated controls. The results of our study, for the first time, provide clear evidence that GE possesses anti-skin tumor-promoting effects, and that the mechanism of such effects may involve inhibition of tumor promoter-caused cellular, biochemical, and molecular changes in mouse skin. (+info)
Faecal phytic acid and its relation to other putative markers of risk for colorectal cancer.
(79/85)
AIMS: Phytic acid, a major constituent of cereals, pulses, and seeds has been advocated as an important antioxidant component of dietary fibre that affords possible protection against colorectal cancer. This is supported by experimental studies showing it has antineoplastic activity in animal models of both colon and breast cancer. To date the concentration of faecal phytic acid in human clinical groups has not been evaluated. Therefore the faecal phytic acid content of adenoma patients drawn from a placebo controlled calcium intervention trial was evaluated. METHODS: Phytic acid was measured in faecal extracts by an improved ion-pair high performance liquid chromatography method. RESULTS: Phytic acid was detected in the range 0.68-4.00 mumol/g wet faeces and 55-2038 mumol/day. Linear regression analyses showed no association between stool phytic acid and lipid content. Strong correlations were seen, however, between phytic acid and iron content, both on a concentration (r = 0.52; p = 0.00004) and daily excretion (r = 0.76; p = 5.5 x 10(-12) basis. Phytic acid was also strongly correlated with the daily excretion of calcium (r = 0.59; p = 1.36 x 10(-6) and magnesium (r = 0.42; p = 0.001). Cell proliferation in the sigmoid colon, an intermediate biomarker of colorectal cancer was not significantly associated with faecal phytic acid, minerals or lipid content in this compromised clinical group. CONCLUSIONS: This improved method, developed for the determination of phytic acid in faeces should allow further studies on the role of phytic acid in the aetiology of colorectal cancer to be conducted on a population or case control basis. (+info)
Spice constituents scavenging free radicals and inhibiting pentosidine formation in a model system.
(80/85)
Many antioxidants have been found in spices and herbs, and some of them are well known as strong scavengers of active oxygen radicals. We have isolated active products, which markedly inhibited the formation of malondialdehyde (MDA from 2-deoxyribose and the hydroxylation of benzoate with the hydroxyl radical, from methanol extracts of allspice and clove. Pimentol from allspice, and biflorin and its isomer, abbreviated as clove3, from clove were identified as the active principles. These revealed strong activity as hydroxyl radical scavengers at a concentration of 2.0 microM. The antioxidative activities in an in vitro model system involving the rabbit erythrocyte membrane ghost were as strong as those of alpha-tocopherol at 200 microM. Such advanced glycation end products (AGE) as pentosidine are biomarkers of diabetes mellitus, and active oxygens have been suggested to be involved in the formation of AGE. The above-mentioned free radical scavengers effectively inhibited the formation of pentosidine in a model system of N alpha-t-butoxycarbonyl-fructoselysine and N alpha-t-butoxycarbonyl-arginine. (+info)