8] Taxol production in nodule cultures of Taxus.
Ellis DD,Zeldin EL,Brodhagen M,Russin WA,McCown BH J Nat Prod1996 Mar, 59:3:246-50
The in vitro synthesis of secondary compounds from plants is one source of scarce and valuable phytopharmaceuticals. Often, some level of cellular or tissue differentiation is needed for the biosynthesis of many of these important compounds. Nodule cultures, consisting of cohesive multicellular units displaying a high degree of differentiation, were initiated from cultured needles of seven Taxus cultivars (Taxus cuspidata, Taxus x media "Hicksii", Taxus x hunnewelliana "Richard Horsey", Taxus x media "Dark Green Spreader", Taxus x media "L. C. Bobbick", and Taxus brevifolia). Under normal semicontinuous perfusion culture
conditions (bimonthly refreshments to yield 0.2% sucrose), only trace amounts of taxol were detected from Taxus nodule cultures. However, with an elevated sucrose level (0.5% or 1.0%), taxol production was enhanced in T. cuspidata nodules to approximately 12 micrograms taxol/g nodule dry weight (dw). Stimulation of taxol production by elevated sucrose levels occurred even in the absence of other nutrients. The effect of increased sucrose on taxol induction does not appear to be due to an osmotic effect in the medium, suggesting that the increase in taxol production may be correlated with a metabolic process within the nodules. Although sucrose had a significant effect on taxol production, taxane precursors or elicitors of
terpenes, as well as other plant secondary metabolites, had no effect on the production of taxol from these cultures. In addition to taxol, the higher sucrose levels also induced the production of 7-epi-10-deacetyltaxol, cephalomannine, and 7-epi-10-deacetylcephalomannine, so that total content of these taxanes equaled approximately 39 micrograms taxane/g dw nodules. Author Address Department of Horticulture, University of Wisconsin, Madison 53706, USA. ELVIS@bcr.bc.ca
9] The antistaphylococcal properties of plant extracts in relation to their prospective use as therapeutic and prophylactic formulations for the skin](Antistafilokokkovye svo&ibreve;stva nekotorykh ékstraktov rasteni&ibreve; v sviazi s perspektivo&ibreve; ispol"zovaniia v lechebno-profilakticheskikh sostavakh dlia kozhi.) Molochko VA,Lastochkina TM,Krylov IA,Brangulis KA Vestn Dermatol Venerol1990,:8:54-6 Abstract
Antistaphylococcal activities of plant extracts (12 water alcohol glycerol, WAG, 6 water alcohol, WA, 8 alcohol glycerol, AG, extracts) towards reference strains and those isolated from patients with pyoinflammatory diseases of the skin were examined by diluting the preparations in solid media. The strains under study were 69 S. aureus, 44 S. epidermidis, and 2 S. saprophyticus ones. Fifteen plant extracts have shown antistaphylococcal activities. The most active were oak bark, sage and St. John"s wort grass WAG extracts, horse radish root and leaf AG extracts, celandine grass WA extract; bur marigold and yarrow grass WA extracts were active towards S. aureus. S. aureus strains isolated from patients were found less sensitive to
oak bark, German camomile flower WAG and celandine, bur marigold, and brewing waste WA extracts that the reference strains. S. epidermidis strains isolated from patients with acne rash were less sensitive to sweet flag rhizome WAG, celandine and brewing waste WA extracts that the reference strains. These data may be useful when developing compositions including plant extracts for patients with skin diseases.
10] Comparison of the skeletal muscle relaxant properties of Portulaca oleracea extracts with dantrolene sodium and methoxyverapamil.
Okwuasaba F,Ejike C,Parry O J Ethnopharmacol1987 Jul, 20:2:85-106
The effects of aqueous (AEE), dialysable (DIF) and methanol (MEE) extracts of Portulaca oleracea stems and leaves were compared with those of dantrolene sodium and methoxyverapamil (D-600) with respect to inhibition of twitch tension on the rat phrenic nerve-hemidiaphragm and with respect to contracture induced by nicotinic agonists on the frog rectus abdominis preparations. The extracts, dantrolene and D-600 inhibited twitch tension due to indirect electrical stimulation via the phrenic nerve (NS) on hemidiaphragm muscle, whereas the extracts and dantrolene inhibited, in addition, twitch amplitude due to direct muscle stimulation (MS). The extracts, dantrolene and D-600 also attenuated K+- and caffeine-induced contractures with the extracts and D-600 also reducing the time taken for the K+-induced contracture to fall to basal tension. In addition, the
tetanic tension due to NS and MS was attenuated with only the extracts and dantrolene reducing the twitch/tetanus ratio (MS). There was a non-significant but consistent tendency for mutual potentiation between the extracts and dantrolene with respect to their inhibitory effect on twitch amplitude (MS) resulting in a shift to the left of the concentration-response curves to the extracts or dantrolene. This was not evident with the extracts and D-600 or dantrolene and D-600. Simultaneous addition of the extracts and dantrolene resulted in an increase in the rate of twitch tension inhibition and a decrease in the time to maximum relaxation of twitch amplitude (MS). The extracts and D-600 proved more effective in attenuating nicotinic agonist (acetylcholine, carbachol and nicotine)-induced contractures on the rectus abdominis muscle than dantrolene. From these
observations, it appears that the Portulaca oleracea extracts mimic, in part, the effect of D-600 and dantrolene on the rat hemidiaphragm and frog rectus abdominis muscles; therefore, the muscle relaxant properties of the extracts may be due, in part, to inhibition of trans-membrane Ca influx, interference with the Ca-induced Ca release process and/or inhibition of the release of intracellular Ca from stores in the sarcoplasmic reticulum. Author Address Department of Pharmacology, University of Jos, Nigeria.
11] Antimicrobial activity of 20 plants used in folkloric medicine in the Palestinian area.
Ali-Shtayeh MS,Yaghmour RM,Faidi YR,Salem K,Al-Nuri MA J Ethnopharmacol1998 Apr, 60:3:265-71
Ethanolic and aqueous extracts of 20 Palestinian plant species used in folk medicine were investigated for their antimicrobial activities against five bacterial species (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa) and one yeast (Candida albicans). The plants showed 90% of antimicrobial activity, with significant difference in activity between the different plants. The most antimicrobially active plants were Phagnalon rupestre and Micromeria nervosa, whereas, the least active plant was Ziziphus spina-christi. Only ten of the tested plant extracts were active against C. albicans, with the most active from M. nervosa and Inula viscosa and the least active from Ruscus aculeatus. Of all extracts the ethanolic extract of M. nervosa was the most active, whereas, the aqueous extract of Phagnalon rupestre was
the most active of all aqueous extracts tested. The ethanolic extracts (70%) showed activity against both Gram positive and negative bacteria and 40% of these extracts showed anticandidal activity, whereas, 50% of the aqueous extracts showed antibacterial activity and 20% of these extracts showed anticandidal activity. Author Address: Department of Biological Sciences, An-Najah National University, Nablus, Palestinian Area.
12] Developmental regulation of a plant encoded inhibitor of eukaryotic initiation factor 2 alpha phosphorylation.
Langland JO,Langland L,Zeman C,Saha D,Roth DA Plant J1997 Aug, 12:2:393-400
An inhibitor of eIF-2a phosphorylation was identified in various plant species. The plant protein (termed PKI) specifically cross-reacts with monoclonal antiserum that recognizes the glycosylated, active form of a M(r) 87 kD protein analog (p67) from reticulocytes. Northern blot analysis using a probe to the reticulocyte inhibitor cDNA further supports the presence of analogous transcripts in plant tissue. PKI specifically inhibits the phosphorylation of the plant encoded eIF-2 alpha kinase
(pPKR) as well as plant and human eIF-2 alpha phosphorylation. The interaction between PKI and pPKR is indicated by their copurification on dsRNA agarose, despite evidence showing that PKI does not bind dsRNA. Further, wheat PKI inhibits human PKR phosphorylation but activity is recovered by immuno-depletion of PKI from wheat germ fractions. PKI is temporally regulated during plant growth and development. It is maximally present in extracts from dormant seeds, however, it is not detectable soon after leaf emergence at approximately 48 h post-imbibition. PKI levels are again detectable at the mid-milk stage in seed development. Protein levels of pPKR in ribosomal salt wash and cytosolic extracts from healthy plant tissue remain essentially constant throughout the life cycle. In contrast, pPKR activity levels based upon autophosphorylation vary significantly and are inversely correlated with PKI protein levels. Phosphorylation of eIF-2 alpha is a classical mechanism for the downregulation of protein synthesis suggesting that inhibition of pPKR activity by PKI may contribute
to the dramatic and rapid increase in protein synthesis observed during seed germination. Author Address Department of Molecular Biology, University of Wyoming, Laramie 82071, USA.
13] Ethnobotany and drug discovery: the experience of the US National
Cancer Institute. Cragg GM,Boyd MR,Cardellina JH 2nd,Newman DJ,Snader KM,McCloud TG Ciba Found Symp1994, 185::178-90; discussion 190-6 Between 1960 and 1981 the National Cancer Institute (NCI) screened 114,000 extracts of 35,000 plants, mainly collected in temperate regions. Of the three clinically active anticancer drugs so far discovered in that programme, none was isolated from a plant collected on an ethnobotanical basis, though various Taxus species, which are the source of taxol, are reported to have been used medicinally. Since 1986, the NCI has focused its collections in tropical and subtropical regions worldwide; collections cover a broad taxonomic range, though priority is given to medicinal plants when relevant information is available. As of August 1993, 21,881 extracts derived from over 10,500 samples had been tested in a screen for activity against the human immunodeficiency virus (HIV); 2320 of these extracts were of medicinal plant origin. Approximately 18% of both the total number of extracts and the medicinal plant-derived extracts showed significant anti-HIV activity; in each instance about 90% of the active extracts were aqueous. The activity of the aqueous extracts has been
attributed mainly to the presence of polysaccharides or tannins. Four plant-derived compounds are in preclinical development at the NCI; only one of the four sources plants, obtained from a noncontract source, was collected on an ethnobotanical basis. At this stage the results indicate that the current NCI collection policy offers the best chances for the discovery and development of agents for the treatment of AIDS (acquired immune deficiency syndrome) and cancer.
Author Address, Developmental Therapeutics Program, National Cancer Institute, Bethesda, Maryland 20892.
14] Inhibitory effect of plant extracts on the collagenolytic activity and cytotoxicity of human gingival fibroblasts by Porphyromonas gingivalis crude enzyme.
Osawa K,Matsumoto T,Yasuda H,Kato T,Naito Y,Okuda K Bull Tokyo Dent Coll1991 Feb, 32:1:1-7
It is well known that plant extracts inhibit some enzymatic activities. The present study examined the inhibitory effects of natural plant extracts against the collagenolytic activity of Porphyromonas gingivalis. The enzyme was isolated from a culture supernatant of P. gingivalis 381. The aqueous and 50% ethanolic extracts of Ginkgo biloba, Mosla chinensis, Salvia officinalis, Cinnamomum cassia, and a catechin extract of Camellia sinensis exhibited strong inhibitory effects on collagenolytic activity.
The activities of these plant extracts were higher than that of tetracycline-HCl. They also inhibited the cytotoxicity of P. gingivalis crude enzyme against human gingival fibroblasts. C. sinensis catechin was the most effective agent in neutralizing the cytotoxicity of P. gingivalis. The aqueous and 50% ethanolic extracts of C. cassia had relatively strong anti-cytotoxic activity. Although the other samples strongly inhibited the collagenolytic activity of P. gingivalis, they were not effectively anti-cytotoxic.
The present findings suggest that C. sinensis and C. cassia extracts are effective in reducing the pathogenicity of periodontopathic bacteria.
Author Address Department of Microbiology, Tokyo Dental College.
15] Comparative studies on tree pollen allergens. XVII. Immunochemical analysis of the international standardization extracts of birch (Betula verrucosa) pollen as compared with a local partially purified extract.
Vik H,Florvaag E,Elsayed S Ann Allergy1987 Jan, 58:1:71-7
Six different birch pollen extracts were analyzed by 20 laboratories for the standardization of birch (Betula verrucosa) pollen extracts used for diagnosis and specific therapy of patients with birch pollen allergy. The extracts were collected and delivered by the International Union of Immunological Societies, Allergen Standardization Subcommittee. One of the extracts, designated M, was proposed as an international standard (IS)-candidate of birch pollen extracts. The protein content of the IS
candidate M was found to be 1.12 mg/mL, more than 2-fold higher than any of the other extracts analyzed. This preparation was among the extracts containing the highest number of protein components, as shown by isoelectric focusing, 28 lines, and by 11 precipitates in crossed immunoelectrophoresis. The allergenic reactivities were tested by crossed dioimmunoelectrophoresis (CRIE) and by radioallergosorbent test (RAST)-inhibition. In CRIE, the proposed IS (M) showed similar affinity for binding patients" IgE as the other extracts, as judged by the autoradiographic illustrations. Except for extract L, the values of RAST-inhibition for the rest were very similar. An IS extract should qualify for the criteria suggested for an optimal allergen preparation, containing minimal amounts of non-allergenic antigens and providing quantitatively and qualitatively all the allergenic proteins. The appropriateness of this selection seems unjustified in view of the Chinese remedies effective for breech birth, irritable bowel syndrome
By Alicia Ault
16] Two studies in the November 11th issue of The Journal of the American Medical Association, researchers report that and cephalic presentation of fetuses in breech position and relieved symptoms of irritable bowel syndrome. WASHINGTON, Nov 11 (Reuters Health) -
The papers, highlighted at a press briefing here Tuesday, are part of a special JAMA issue devoted to the effectiveness of so-called alternative therapies. Two other studies published in the current issue on use of herbal teas and supplements for weight loss and spinal manipulation for episodic tension-type headaches showed that herbal teas and spinal manipulation for
these indications were no more efficacious than placebo. In the paper on irritable bowel syndrome, Alan Bensoussan and colleagues at the University of Western Sydney, Australia, evaluated 116 patients diagnosed with irritable bowel syndrome by gastroenterologists and then seen by Chinese herbalists. The herbalists wrote prescriptions, which were filled by researchers trained in Chinese methods. Patients were randomized to receive either an individually tailored Chinese remedy, a
standardized Chinese remedy, or placebo. Those receiving the standard Chinese remedy responded significantly better in five outcomes, including total mean Bowel Symptom Scale scores, than those receiving placebo. Symptom scores for patients receiving the standard and individualized remedies were two to three times better than the symptom scores for those given
placebo, Bensoussan said . Some gastroenterologists were taken aback, but "...to Chinese medicine practitioners, this comes as no surprise," he said at the press conference. The remedy was complex, containing about 20 herbs to balance active effects with potentially toxic effects. Bensoussan said that the Chinese practitioners have at least 5 years' training in evaluation of different herbal properties and how to combine herbs as remedies. Bensoussan plans to repeat the study with extracts, which are more potent and more expensive than powders used in this trial. In the second study, conducted at two hospitals in Jiangxi Province in China, 260 women in the 32nd week of pregnancy presenting with fetuses in breech position were assigned to receive either moxibustion or observation.
Moxibustion involves burning of the herb Artemisia vulgaris in a rolled-up tube placed directly next to the outside corner of the fifth toenail of each foot. The technique is supposed to stimulate an acupuncture point, and seems to cause fetal movement, said coauthor Dr. Francesco Cardini, a gynecologist from Verona, Italy. Moxibustion was performed once or twice daily for a total of 30 minutes for 1 or 2 weeks. By the 35th week, 75.4% of fetuses in the moxibustion group were cephalic compared with only 47.7% of the control group. There were no side effects or adverse events, Dr. Cardini said. Although Dr. Cardini concludes that the technique is easy and can be done at home, he says that he "...doesn't know how long it would take for Western midwives to learn the technique." He told those in attendance at the press conference that midwives in Verona have rapidly adopted the method.
In another study, Dr. Steven B. Heymsfield and colleagues at the Obesity
Research Center of St. Luke's-Roosevelt Hospital, New York, discovered
that the herbal compound Garcinia cambogia, contained in many teas and
remedies, did not produce greater weight loss than placebo. The compound
has shown promise in animal studies, but Dr. Heymsfeld said that those
results do not translate to humans, possibly because lower doses were used
in human trials.
He warned that Garcinia cambogia purchasers might not be wasting just money. "They go and buy these herbal products instead of seeking a diagnosis," he said, noting that some conditions, such as diabetes or gallstones, might go untreated.
Also at the press conference, Dr. Geoffrey Bove, of Beth Israel Deaconess
Medical Center, Boston, said that, despite previous findings that spinal
manipulation is effective for some types of headache, it did not seem to
make a difference in treating episodic tension-type headache. "These data
underline the importance of accurate diagnosis," Bove said.
-Westport Newsroom 203 319 2700
17] Axis Genetics signs agreements to develop vaccines in plants LONDON, Nov 11 (Reuters Health) - Axis Genetics, based in Cambridge, UK, has signed three research agreements with institutions in the US to develop vaccines, in plants, designed to protect against hepatitis B and breast cancer.
In a statement on Monday, Axis officials said that the company has commissioned American Ag-Tech International of Delavan, Wisconsin, to produce potatoes containing hepatitis B edible plant vaccine for use in an oral hepatitis B clinical trial in 1999 and for further product development. In a second agreement, the UK company will collaborate with scientists at Roswell Park Cancer Institute in Buffalo, New York, to further develop the first edible plant vaccine. Scientists will analyze the immune
response in animals to edible plant vaccine potatoes designed to contain hepatitis B antigens. In a third agreement, Axis will work with cancer vaccine specialist Biomira to speed the development of a vaccine that might protect against breast cancer. The potential therapy would target the MUC-1 peptide found on 90% of common solid tumours, the company said.
London Newsroom +44 171 542 6472
18] FDA concludes that soy protein reduces risk of coronary heart disease. By Steve Pincock
WESTPORT, Nov 11 (Reuters Health) - Eating four servings each day of food that contains soy protein, such as soy milk or shakes, tofu or meat substitutes, may reduce the risk of coronary heart disease as part of a low-fat diet, according to Food and Drug Administration officials. The administration has proposed allowing certain soy products to carry a claim on labels stating that "...diets low in saturated fat and cholesterol that include 25 grams of soy protein per day may reduce the risk of heart
disease." "We considered that it would be possible to get 25 g of soy protein in four eating occasions during the day,"
Dr. Susan Pilch, from the FDA's Office of Special Nutritionals told Reuters Health. "That means that a food would have to have 6.25 g of soy protein to bear the claim." She said that many soy products meet the 6.25-g standards, and some would contain even higher levels. "A vegetable burger may satisfy half of the requirement for 25 g a day," she said, "...and some shakes that can be made with soy protein might give 25 g in one serving."
No particular cooking method alters the effect of the soy protein, Dr. Pilch said. The data that FDA used to support the claim came from animal studies in which the soy was cooked into baked products, given in drinks and cooked in meat-substitute products.
FDA says that the soy protein seems to alter the synthesis and metabolism of cholesterol in the liver. By
lowering the total blood cholesterol and low-density lipoprotein cholesterol, soy protein can reduce the risk of
"One of the stronger hypotheses for the action of soy proteins has to do with its amino acid composition, which is somewhat unique among food proteins in being rather high in alanine and having a high alanine to glycine ratio," Dr. Pilch told Reuters Health. "It appears from animal studies that the pattern of amino acids seen in soy proteins versus the pattern seen in casein can alter the metabolism of cholesterol in the liver, possibly by some direct action or by influencing the ratio of insulin to glucagon," she said. Westport Newsroom 203 319 2700
19] Human Genome Project ahead of schedule, under budget
DALLAS, Nov 11 (Reuters Health) - To a standing-room-only crowd in the arena of the Dallas Convention Center, the founder and director of the NIH's Human Genome Project told the 71st gathering of the American Heart Association that the undertaking is years ahead of schedule and under budget.
"The year 2005 isn't good enough anymore," Dr. Francis S. Collins declared, referring to the scheduled year of completion of the 15-year project. Instead, the project is on a course that should see it completed by the year 2003--the year, he noted, of the 50th anniversary of the discovery of the double helix.
Dr. Collins said that he expects to have a "working draft" of the entire human DNA sequence by 2001. More than half the sequencing is already completed. And, he is adamant that the information be available on the Internet and in the hands of the public, where "it can do the most good." -Westport Newsroom 203 319 2700
20] AHA advisory: more fruits, vegetables to reduce elevated homocysteine levels.
DALLAS, Nov 11 (Reuters Health) - The American Heart Association is recommending, in a science advisory issued here during its 71st scientific sessions, an increased dietary intake of vitamin B6, B12 and folic acid to meet the RDAs for individuals with elevated homocysteine levels and a history of heart disease. Plasma levels of these vitamins are inversely related to levels of homocysteine . Experts cautioned during the announcement of the new recommendations that hard evidence of the benefits of lowering homocysteine levels to reduce risk of coronary artery disease is still lacking. Advisory committee member Dr. Ronald Krauss of Lawrence Berkeley National Laboratory in California noted that there are only 11 prospective trials to assess the risk of elevated homocysteine levels on cardiovascular disease, and only 6 of those show a positive association.
Investigators presented current findings from three prospective studies supporting the link between elevated homocysteine levels and risk of heart disease. Dr. Paul M. Ridker, from Brigham and Women's Hospital, in Boston, Massachusetts, said that findings from the Women's Health Study of 244 apparently healthy women show a "modest" association between elevated homocysteine and later risk of myocardial infarction. Dr. Peter W. F. Wilson, of the National Heart Lung and Blood Institute, reported that data on 1947 elderly individuals in the Framingham Heart Study show a link between homocysteine and stroke.
Dr. Winfried A. Willinek of the University of Bonn presented the strongest data to support a link. He said that elevated homocysteine proved to be an independent risk factor for common carotid wall thickening, as were body mass index and elevated LDL cholesterol, in 75 apparently healthy men and women. When BMI, LDL and homocysteine were considered together, homocysteine contributed to 18% of the risk of carotid atherosclerosis. "Until results of controlled clinical trials become available, emphasis should be placed on meeting current RDAs for folate as well as vitamins B6 and B12, by intake of vegetables, fruits, legumes and fortified grains and cereals," the advisory panel says. Vitamin supplementation--folic acid 400 micrograms; vitamin B6 2 mg; vitamin B12 6 micrograms--with careful monitoring might be necessary in some high-risk patients, and higher dosages may be required in some cases. But the experts caution that such treatment is still experimental.
They say that a "reasonable approach" to risk assessment would be to measure fasting homocysteine levels in high risk individuals, including those with a personal or family history of cardiovascular disease, impaired kidney function, lupus and malnutrition. Determinations may also be advisable in patients on theophylline, nicotinic acid, methotrexate and levodopa and also for those exposed to nitrous oxide. Dr. Krauss stressed that widespread population-based screening is not recommended at this time. The recommendations will be published in the January 5th issue of Circulation: Journal of the American Heart
Association. -Westport Newsroom 203 319 2700