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.
JAMA 1998;280:1576-1579,1580-1584,1585-1589,1596-1600.
-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
CHD.
"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