 |
 |
| |
Printable Version
 |
|
| |
| |
|
Department of Food Science, Veterinary
Faculty, University of Murcia, Spain. mamurcia@um.es.
The antioxidant properties of
two raw truffles (Terfezia claveryi Chatin and Picoa
juniperi Vittadini) and five raw mushrooms (Lepista
nuda, Lentinus edodes, Agrocybe cylindracea, Cantharellus
lutescens, and Hydnum repandum) were tested by subjecting
these truffles and mushrooms to different industrial
processes (freezing and canning) and comparing them
with common food antioxidants (alpha-tocopherol [E-307],
BHA [E-320], BHT [E-321], and propyl gallate [E-310])
with regard to their ability to inhibit lipid oxidation.
All of the truffles and mushrooms analyzed exhibited
higher percentages of oxidation inhibition than did
the food antioxidants according to assays based on lipid
peroxidation (LOO*), deoxyribose (OH*), and peroxidase
(H2O2). Frozen samples exhibited a small reduction in
free radical scavenger activity, but the results did
not show a significant difference (P < 0.05) with respect
to the raw samples, while canned truffles and mushrooms
lost some antioxidant activity as a consequence of industrial
processing. All of the raw and frozen truffles and mushrooms
except frozen Cantharellus improved the stability of
oil against oxidation (100 degrees C Rancimat), while
canned samples accelerated oil degradation. Antioxidant
activity during 30 days of storage was measured by the
linoleic acid assay, and all of the samples except canned
Terfezia, Picoa, and Hydnum showed high or medium antioxidant
activity. The Trolox equivalent antioxidant capacity
assay was used to provide a ranking order of antioxidant
activity as measured against that of Trolox (a standard
solution used to evaluate equivalent antioxidant capacity).
The order of raw samples with regard to antioxidant
capacity was as follows (in decreasing order): Cantharellus,
Agrocybe, Lentinus, Terfezia, Picoa, Lepista, and Hydnum.
Losses of antioxidant activity were detected in the
processed samples of these truffles and mushrooms.
|
|
|
Division of Life Science, Graduate
School of Science and Technology, Kobe University, Japan.
The changes in the contents of
an anti-tumor polysaccharide from Lentinus edodes (lentinan)
and Grifolafrondosa (GGF) during storage were investigated
using by an ELISA inhibition assay. When the mushrooms
were stored at low temperature, the contents of their
anti-tumor polysaccharides show hardly any changes,
but their contents decreased markedly at higher temperature
(20 degrees C). Moreover, the effect of the extract
from Lentinus edodes stored at different temperatures
on tumor necrosis factor (TNF)-alpha and nitric oxide
(NO) productions from macrophages was investigated to
confirm the influence to the stimulation of macrophages.
Because lentinan stimulates macrophages to augment their
antitumor activity. Their productions showed little
difference between Lentinus edodes stored at low temperature
and the fresh mushroom, although the cytokine production
decreased significantly in Lentinus edodes stored at
20d egrees C. These results suggest that low-temperature
storage is more effective in maintaining not only the
quality of the mushrooms but also the contents of anti-tumor
polysaccharides as health-beneficient foods.
|
|
|
Department of Medicine, Memorial
Sloan-Kettering Cancer Center, New York, USA.
Edible mushrooms such as shiitake
may have important salutary effects on health or even
in treating disease. A mushroom characteristically contains
many different bioactive compounds with diverse biological
activity, and the content and bioactivity of these compounds
depend on how the mushroom is prepared and consumed.
It is estimated that approximately 50% of the annual
5 million metric tons of cultivated edible mushrooms
contain functional "nutraceutical" or medicinal properties.
In order of decreasing cultivated tonnage, Lentinus
(shiitake), Pleurotus (oyster), Auricularia (mu-er),
Flammulina (enokitake), Tremella (yin-er), Hericium,
and Grifola (maitake) mushrooms have various degrees
of immunomodulatory, lipid-lowering, antitumor, and
other beneficial or therapeutic health effects without
any significant toxicity. Although the data for this
functional food class are not as strong as those for
other functional foods such as cruciferous vegetables,
because of their potential usefulness in preventing
or treating serious health conditions such as cancer,
acquired immune deficiency syndrome (AIDS), and hypercholesterolemia,
functional mushrooms deserve further serious investigation.
Additionally, there is a need for epidemiological evidence
of the role of this functional food class.
|
|
|
Osrodka Badawczo-Rozwojowego Produkcji
Lesnej Las, Konstancinie-Jeziornie
The amount of lead, cadmium, copper,
zinc and mercury has been determined by atomic absorption
spectroscopy in 96 samples of edible mushrooms, growing
wild fresh edible fungus and dried (Boletus scaber,
ceps) mushrooms, acquired from 6 regions in Poland:
Zielonogorskie, Torunskie, Ostroleckie, Radomskie, Warszawskie
and Lubelskie in 1990 and 1991. The level was found
to be higher than that allowed by the polish standard
PN-89/A-78510 Mushroom Processed Foods. Dried mushrooms
and other legal acts eg. Instruction of the Ministry
of Health section Social Welfare of 12th November 1990,
the content of zinc in dried mushrooms (all samples)
and in fresh edible fungus from the Zielonogorski and
Torunski region. The content of copper in fresh edible
fungus did not usually correspond with the requirements,
whereas in the dried mushrooms (Boletus scaber, ceps)
it exceeded the level only insignificantly in individual
samples (average from studied regions was found to be
within limits). The content of lead in dried mushrooms
complied with the requirements of the standard, except
for samples of ceps from Zielonogorski region, where
it insignificantly exceeded the allowed level of 2.0
mg/kg. The average content of zinc and copper in dried
mushrooms did not exceed the allowed levels. The levels
of mercury determined in the studied samples do not
cause any excitement in light of the FAO/WHO agreements.
A high level of contamination with cadmium was noted
in all studied samples, being 2.5 times higher in edible
fungus, 6-8 times higher in Boletus scaber and 19-23
times higher in dried ceps.
|
|
|
Department of Microbiology, Nihon
University School of Dentistry at Matsudo, Chiba, Japan.
The caries-inhibiting effect of
the extract from shiitake (Lentinus edodes), the most
popular edible mushroom in Japan, was studied both in
vitro and in vivo. Shiitake extract showed an inhibitory
effect on water-insoluble glucan formation from sucrose
by crude glucosyltransferases of Streptococcus mutans
JC-2 and Streptococcus sobrinus OMZ-176. The firmly
adherent plaque in the artificial plaque formation test
was strongly inhibited by shiitake extract. The reduction
of firmly adherent plaque caused an increase in the
incidence of non- and loosely adherent plaque and a
decrease in total plaque formation. A significantly
lower caries score was observed in specific pathogen-free
rats infected with S. mutans JC-2 and fed with a cariogenic
diet containing 0.25% shiitake extract as compared with
controls fed the cariogenic diet without shiitake extract.
|
|
|
Institute for Mushroom Research,
GAMU Ltd., Krefeld, Germany.
According to the stand of the
modern applied mycological research the most commonly
used term "edible mushroom" does not express all significant
aspects large fungi can be used for. Additionally to
bioconversion for food and animal feed production there
are at least three other fields where large fungi may
also get economical relevance: for establishing of ectomycorrhiza,
for medical application and for soil decontamination
including environmental engineering. This new situation
justifies the introduction of a new, all-embracing designation
for large fungi. The term "useful mushroom" will be
suggested. The various options of the use of mushrooms
will be introduced and briefly discussed in this paper.
|
|
|
University Department of Dermatology,
University of Liverpool, UK.
Lectins or agglutinins are proteins
with affinity for specific sugar residues. Peanut agglutinin
(PNA) and the lectin from the edible mushroom (Agaricus
bisporus, ABL) both bind to the disaccharide galactosyl
beta-1,3-N-acetyl galactosamine alpha-. This is expressed
in keratinocytes as an O-linked chain on CD44, a polymorphic
membrane glycoprotein. Many lectins are mitogens and
PNA is a mitogen for colonic epithelial cells. However,
ABL reversibly inhibits proliferation of colonic cancer
cell lines without cytotoxicity and thus has therapeutic
potential in situations such as psoriasis where proliferation
is increased. We have therefore investigated the effect
of ABL on the growth of normal human cultured keratinocytes
and a human papilloma virus (HPV)-transformed cell line.
In a 5-day dose-response study, keratinocyte growth
was greatly reduced by 1.0 microg/mL ABL and completely
inhibited by 3.0 microg/mL ABL (ANOVA, P < 0.0001).
Exposure to 1.0 microg/mL ABL for only 8 h gave the
same growth inhibition as did continued exposure for
3 days. No cytotoxic or morphological changes were observed.
An HPV-immortalized cell line was relatively resistant
to ABL: in a 5-day dose-response study, exposure to
30 microg/mL was required to inhibit cell growth completely.
Topical application of ABL 0.01% or 0.1% to normal human
skin caused no change in skin erythema, blood flow or
thickness compared with vehicle or baseline (n = 6).
ABL 0. 1% in white soft paraffin was compared with vehicle
in 11 psoriatic patients, using comparative contralateral
plaques. Twice daily application for 2 weeks showed
no significant difference from vehicle-treated sites,
although the skin thickness of plaques fell from 5.3
+/- 0.4 (n = 11, mean +/- SEM) to 4.1 +/- 0.3 mm. In
view of the in vitro results further studies are warranted,
particularly if means can be found to improve the epidermal
penetration of the relatively large ABL molecule (60
kDa).
|
|
|
Discipline of Fruits, Vegetables,
and Plantation Crops, Central Food Technological Research
Institute, Mysore, India.
The fruit bodies of Pleurotus
species as a class of "Edible Fungal Foods" have been
discovered to have definite nutritive and medicinal
values. They are a good source of nonstarchy carbohydrates,
dietary fiber (that can help in reducing the plasma
cholesterol), most of the essential amino acids, minerals
and vitamins of B group, and folic acid (necessary to
counteract pernicious anaemia) in particular. Considering
the essential amino acid index, biological value, in
vitro digestibility, nutritional index, and protein
score, Pleurotus species fall between high grade vegetables
and low grade meats. Fractions of water-soluble polysaccharides
are reported to possess antitumor activity. The physiological
processes such as changes in water content, respiratory
rate, texture, color, and activities of enzymes like
proteases and polyphenol oxidases during the after-harvest
life are delineated. The problems and prospects of processing
the fruit bodies by various methods are discussed. Potentialities
for production and consumption of the fruit bodies in
different parts of the world are brought out..
|
|
|
Agricultural Technology Institute
of Nagano Farmers' Federation, Japan.
The in vivo effect of Hypsizigus
marmoreus on the plasma antioxidant status of tumor-bearing
mice was examined. Female DBA/2 mice treated with subcutaneous
injection of 3-methylcholanthrene were fed on a basal
diet (CE-2) or CE-2 containing 5% fruit bodies of the
mushroom for 76 weeks. Antioxidant activities (AOA)
of mice with tumor were significantly higher than those
of mice without tumor. The high levels of AOA were attributable
to the increase of high molecular weight AOA in the
plasma. A similar increase in plasma AOA was also observed
in sarcoma-180 solid tumor-bearing mice. The mushroom
feeding exhibited a potent antitumor effect and caused
a significant decrease in lipid peroxide levels (as
thiobarbituric acid reactive substances; TBARS). These
results suggest that the increase of AOA in the plasma
of tumor-bearing mice is one of the mechanism of cancer
preventive effects and also suggest that Hypsizigus
marmoreus might play a role in decreasing TBARS by controlling
AOA induction.
|
|
|
Department of Microbial Chemistry,
Kobe Pharmaceutical University, Japan.
OBJECTIVE: To determine the efficacy
of maitake mushrooms in inhibiting the elevation of
liver and serum lipids in rats. DESIGN: Sprague-Dawley
rats with hyperlipidemia were used to measure and compare
the values of cholesterol, phospholipids, and triglycerides
between cholesterol-fed rats and rats whose diets were
fortified with 20% maitake mushroom dried powder. RESULTS:
The values in maitake-fed rats were consistently less
than those in the basic cholesterol-fed rats. The value
of high-density lipoprotein cholesterol, which usually
is decreased by taking high-cholesterol feed, maintained
the level that it had at the beginning of the experiment.
Weights of extirpated liver and epididymal fat pads
were significantly less than those in the basic feed
group. CONCLUSION: Our data suggest that maitake mushrooms
have the ability to alter lipid metabolism by inhibiting
both the accumulation of liver lipids and the elevation
of serum lipids. Further studies are needed to elucidate
the mechanism of activity of maitake mushrooms and to
establish whether their action in humans is similar
to that in the animal model tested here.
|
|
|
Agricultural Research Centre of
Finland, Food Research, Building L, 31600 Jokioinen,
Finland. pirjo.mattila@mtt.fi
The aim of the study was to determine
the contents of mineral elements (Ca, K, Mg, Na, P,
Cu, Fe, Mn, Cd, Pb, and Se), vitamins (B(1), B(2), B(12),
C, D, folates, and niacin), and certain phenolic compounds
(flavonoids, lignans, and phenolic acids) in the cultivated
mushrooms Agaricus bisporus/white, Agaricus bisporus/brown,
Lentinus edodes, and Pleurotus ostreatus. Selenium,
toxic heavy metals (Cd, Pb), and other mineral elements
were analyzed by ETAAS, ICP-MS, and ICP methods, respectively;
vitamins were detected by microbiological methods (folates,
niacin, and vitamin B(12)) or HPLC methods (other vitamins),
and phenolic compounds were analyzed by HPLC (flavonoids)
or GC--MS methods (lignans and phenolic acids). Cultivated
mushrooms were found to be good sources of vitamin B(2),
niacin, and folates, with contents varying in the ranges
1.8--5.1, 31--65, and 0.30--0.64 mg/100 g dry weight
(dw), respectively. Compared with vegetables, mushrooms
proved to be a good source of many mineral elements,
e.g., the contents of K, P, Zn, and Cu varied in the
ranges 26.7--47.3 g/kg, 8.7--13.9 g/kg, 47--92 mg/kg,
and 5.2--35 mg/kg dw, respectively. A. bisporus/brown
contained large amounts of Se (3.2 mg/kg dw) and the
levels of Cd were quite high in L. edodes (1.2 mg/kg
dw). No flavonoids or lignans were found in the mushrooms
analyzed. In addition, the phenolic acid contents were
very low.
|
|
|
The bioavailability of selenium
(Se) in mushrooms, Boletus edulis, to young Finnish
women was studied by giving them 150 micrograms Se as
mushrooms for 4 weeks. The indicators of body selenium
status were plasma and erythrocyte Se levels and plasma
and platelet glutathione peroxidase (GSH-Px) activity.
The Se level in erythrocytes increased significantly
(26%), while only slight enhancement were found in plasma
Se and plasma or platelet GSH-Px activity. The results
indicate that the metabolism of mushroom-Se is different
from that of wheat-Se or sodium selenate. However, by
the criteria of plasma Se level or plasma and platelet
GSH-Px activity the bioavailability of mushroom-Se is
reasonably low.
|
|
|
The selenium contents of 83 species
of wild mushrooms were determined by oxygen combustion
of the sample, followed by conversion of selenite to
bromopiazselenol and final estimation by electron capture
gas-liquid chromatography. Selenium concentration were
found to range from 0.012-20.0 mg/kg dry weight. Selenium
content was species-dependent. High concentrations were
found in Agaricaceae and in certain Boletaceae of the
genus Tubiporus, whereas in Russulaceae, Amanitaceae
and Cantharellaceae selenium-rich species were absent
or rare. Ascomycetes and all mushrooms growing on wood
had a very low selenium content. The highest selenium
concentrations (up to 20 ppm) were found in Boletus
(Tubiporus) edulis, a most popular edible mushroom.
Analyses of various parts of carpophores of B. edulis,
Suillus luteus and Amanita muscaria indicate that in
all three species the stalk contains less selenium than
the fleshy part of the cap. In Boletus and Suillus the
highest selenium content was found in the tubes.
|
|
|
Department of Food Science, National
Chung-Hsing University, 250 Kuokuang Road, Taichung
40227, Taiwan, Republic of China. jlmau@dragon.nchu.edu.tw
Five kinds of ear mushrooms are
commercially available in Taiwan, including black, red,
jin, snow, and silver ears. Methanolic extracts were
prepared from these ear mushrooms, and their antioxidant
properties were studied. For all methanolic extracts
from ear mushrooms, the antioxidant activities in the
1,3-diethyl-2-thiobarbituric acid method were moderate
(38.6 approximately 74.6%) at 1.0-5.0 mg/mL. Methanolic
extracts from red, jin, and snow ears showed excellent
antioxidant activities in the conjugated diene method
at 5.0 mg/mL. At 5.0 mg/mL, reducing powers of methanolic
extracts were in the descending order of snow > black
approximately red approximately jin > silver ears. The
scavenging effect of methanolic extracts from ear mushrooms
on 1,1-diphenyl-2-picrylhydrazyl radicals was excellent
except for that from silver ears. Ear mushroom extracts
were not good scavengers for hydroxyl free radicals
but were good chelators for ferrous ions. Naturally
occurring antioxidants, including ascorbic acid, tocopherols,
and total phenols, were found in the methanolic extracts.
However, beta-carotene was not detected. Total antioxidant
components were 15.69, 30.09, 27.83, 49.17, and 31.70
mg/g for black, red, jin, snow, and silver ears, respectively.
|
|
|
Department of Food Science, National
Chung-Hsing University, 250 Kuokuang Road, Taichung
402, Taiwan, Republic of China. jlmau@dragon.nchu.edu.tw
Three species of medicinal mushrooms
are commercially available in Taiwan, namely, Ganoderma
lucidum (Ling-chih), Ganoderma tsugae (Sung-shan-ling-chih),
and Coriolus versicolor (Yun-chih). Methanolic extracts
were prepared from these medicinal mushrooms and their
antioxidant properties studied. At 0.6 mg/mL, G. lucidum,
G. lucidum antler, and G. tsugae showed an excellent
antioxidant activity (2.30-6.41% of lipid peroxidation),
whereas C. versicolor showed only 58.56%. At 4 mg/mL,
reducing powers were in the order G. tsugae (2.38) approximately
G. lucidum antler (2.28) > G. lucidum (1.62) > C. versicolor
(0.79). At 0.64 mg/mL, scavenging effects on the 1,1-diphenyl-2-picrylhydrazyl
radical were 67.6-74.4% for Ganoderma and 24.6% for
C. versicolor. The scavenging effect of methanolic extracts
from G. lucidum and G. lucidum antler on hydroxyl radical
was the highest (51.2 and 52.6%) at 16 mg/mL, respectively.
At 2.4 mg/mL, chelating effects on ferrous ion were
in the order G. lucidum antler (67.7%) > G. lucidum
(55.5%) > G. tsugae (44.8%) > C. versicolor (13.2%).
Total phenols were the major naturally occurring antioxidant
components found in methanolic extracts from medicinal
mushrooms. Overall, G. lucidum and G. tsugae were higher
in antioxidant activity, reducing power, scavenging
and chelating abilities, and total phenol content.
|
|
|
Amala Cancer Research Centre, Amala
Nagar, Thrissur, India.
The methanolic extract of a macrofungus,
P. rimosus possessed significant in vitro superoxide
anion, hydroxyl radical and nitric oxide scavenging
and lipid peroxidation inhibiting activities. The anti-inflammatory
activity of the extract was evaluated in carrageenan
and dextran induced acute and formalin induced chronic
inflammatory models in mice. The extract showed remarkable
anti-inflammatory activity in both models, comparable
to the standard reference drug diclofenac. The results
suggest that the anti-inflammatory activity of the methanol
extract of P. rimosus is possibly attributed to it's
free radical scavenging properties. The findings also
reveal the potential therapeutic value of P.rimosus
extract as an antiinflammatory agent.
|
|
|
Department of Urology, New York
Medical College, Valhalla, New York 10595, USA.
PURPOSE: To explore more effective
treatment for hormone-refractory prostate cancer, we
investigated the potential antitumor effect of beta-glucan,
a polysaccharide of the Maitake mushroom, on prostatic
cancer cells in vitro. MATERIALS AND METHODS: Human
prostate cancer PC-3 cells were treated with various
concentrations of the highly purified beta-glucan preparation
Grifron-D(R) (GD), and viability was determined at 24
h. Lipid peroxidation (LPO) assay and in situ hybridization
(ISH) were performed to unravel the antitumor mechanism
of GD. RESULTS: A dose-response study showed that almost
complete (>95%) cell death was attained in 24 h with
GD > or = 480 microg/mL. Combinations of GD in a concentration
as low as 30 to 60 microg/mL with 200 microM vitamin
C were as effective as GD alone at 480 microg/mL, inducing
>90% cytotoxic cell death. Simultaneous use with various
anticancer drugs showed little potentiation of their
efficacy except for the carmustine/GD combination (approximately
90% reduction in cell viability). The significantly
(twofold) elevated LPO level and positive ISH staining
of GD-treated cells indicated oxidative membrane damage
resulting in apoptotic cell death. CONCLUSION: A bioactive
beta-glucan from the Maitake mushroom has a cytotoxic
effect, presumably through oxidative stress, on prostatic
cancer cells in vitro, leading to apoptosis. Potentiation
of GD action by vitamin C and the chemosensitizing effect
of GD on carmustine may also have clinical implications.
Therefore, this unique mushroom polysaccharide may have
great a potential as an alternative therapeutic modality
for prostate cancer.
|
|
|
Institute of Evolution, University
of Haifa, Mt. Carmel, Haifa 31905, Israel. spwasser@research.haifa.ac.il
The number of mushrooms on Earth
is estimated at 140,000, yet maybe only 10% (approximately
14,000 named species) are known. Mushrooms comprise
a vast and yet largely untapped source of powerful new
pharmaceutical products. In particular, and most importantly
for modern medicine, they represent an unlimited source
of polysaccharides with antitumor and immunostimulating
properties. Many, if not all, Basidiomycetes mushrooms
contain biologically active polysaccharides in fruit
bodies, cultured mycelium, culture broth. Data on mushroom
polysaccharides have been collected from 651 species
and 7 infraspecific taxa from 182 genera of higher Hetero-
and Homobasidiomycetes. These polysaccharides are of
different chemical composition, with most belonging
to the group of beta-glucans; these have beta-(1-->3)
linkages in the main chain of the glucan and additional
beta-(1-->6) branch points that are needed for their
antitumor action. High molecular weight glucans appear
to be more effective than those of low molecular weight.
Chemical modification is often carried out to improve
the antitumor activity of polysaccharides and their
clinical qualities (mostly water solubility). The main
procedures used for chemical improvement are: Smith
degradation (oxydo-reducto-hydrolysis), formolysis,
and carboxymethylation. Most of the clinical evidence
for antitumor activity comes from the commercial polysaccharides
lentinan, PSK (krestin), and schizophyllan, but polysaccharides
of some other promising medicinal mushroom species also
show good results. Their activity is especially beneficial
in clinics when used in conjunction with chemotherapy.
Mushroom polysaccharides prevent oncogenesis, show direct
antitumor activity against various allogeneic and syngeneic
tumors, and prevent tumor metastasis. Polysaccharides
from mushrooms do not attack cancer cells directly,
but produce their antitumor effects by activating different
immune responses in the host. The antitumor action of
polysaccharides requires an intact T-cell component;
their activity is mediated through a thymus-dependent
immune mechanism. Practical application is dependent
not only on biological properties, but also on biotechnological
availability. The present review analyzes the pecularities
of polysaccharides derived from fruiting bodies and
cultured mycelium (the two main methods of biotechnological
production today) in selected examples of medicinal
mushrooms.
|
|
|
School of Pharmacy, Faculty of
Medicine, Chinese University of Hong Kong, Shatin, NT.
Coriolus versicolor (CV) is a
medicinal mushroom widely prescribed for the prophylaxis
and treatment of cancer and infection in China. In recent
years, it has been extensively demonstrated both preclinically
and clinically that aqueous extracts obtained from CV
display a wide array of biological activities, including
stimulatory effects on different immune cells and inhibition
of cancer growth. The growing popularity of aqueous
CV extracts as an adjunct medical modality to conventional
cancer therapies has generated substantial commercial
interest in developing these extracts into consistent
and efficacious oral proprietary products. While very
limited information is available on the physical, chemical,
and pharmacodynamic properties of the active principles
present in these extracts, there has been sufficient
scientific evidence to support the feasibility of developing
at least some of these constituents into an evidence-based
immunodulatory agent. In this article, the background,
traditional usage, pharmacological activities, clinical
effects, adverse reactions, active constituents, and
regulatory aspects of CV are reviewed. Presented also
in this review are the current uses and administration,
potential drug interactions, and contraindication of
aqueous extracts prepared from CV.
|
|
|
Division of Rheumatology/Allergy
and Clinical Immunology, University of California at
Davis School of Medicine, Davis, California 95616-8660,
USA.
Medicinal properties have been
attributed to mushrooms for thousands of years. Mushroom
extracts are widely sold as nutritional supplements
and touted as beneficial for health. Yet, there has
not been a critical review attempting to integrate their
nutraceutical potential with basic science. Relatively
few studies are available on the biologic effects of
mushroom consumption, and those have been performed
exclusively in murine models. In this paper, we review
existing data on the mechanism of whole mushrooms and
isolated mushroom compounds, in particular (1-->3)-beta-D-glucans,
and the means by which they modulate the immune system
and potentially exert tumor-inhibitory effects. We believe
that the antitumor mechanisms of several species of
whole mushrooms as well as of polysaccharides isolated
from Lentinus edodes, Schizophyllum commune, Grifola
frondosa, and Sclerotinia sclerotiorum are mediated
largely by T cells and macrophages. Despite the structural
and functional similarities of these glucans, they differ
in their effectiveness against specific tumors and in
their ability to elicit various cellular responses,
particularly cytokine _expression and production. Unfortunately,
our data base on the involvement of these important
mediators is still rather limited, as are studies concerning
the molecular mechanisms of the interactions of glucans
with their target cells. As long as it remains unclear
what receptors are involved in, and what downstream
events are triggered by, the binding of these glucans
to their target cells, it will be difficult to make
further progress in understanding not only their antitumor
mechanisms but also their other biological activities.
|
|
|
International Centre for Cryptogamic
Plants and Fungi, Institute of Evolution, University
of Haifa, Israel.
This review highlights some of
the recently isolated and identified substances of higher
Basidiomycetes mushrooms origin that express promising
antitumor, immune modulating, cardiovascular and hypercholesterolemia,
antiviral, antibacterial, and antiparasitic effects.
Medicinal mushrooms have a long history of use in folk
medicine. In particular, mushrooms useful against cancers
of the stomach, esophagus, lungs, etc. are known in
China, Russia, Japan, Korea, as well as the U.S.A. and
Canada. There are about 200 species of mushrooms that
have been found to markedly inhibit the growth of different
kinds of tumors. Searching for new antitumor and other
medicinal substances from mushrooms and to study the
medicinal value of these mushrooms have become a matter
of great significance. However, most of the mushroom
origin antitumor substances have not been clearly defined.
Several antitumor polysaccharides such as hetero-beta-glucans
and their protein complexes (e.g., xyloglucans and acidic
beta-glucan-containing uronic acid), as well as dietary
fibers, lectins, and terpenoids have been isolated from
medicinal mushrooms. In Japan, Russia, China, and the
U.S.A. several different polysaccharide antitumor agents
have been developed from the fruiting body, mycelia,
and culture medium of various medicinal mushrooms (Lentinus
edodes, Ganoderma lucidum, Schizophyllum commune, Trametes
versicolor, Inonotus obliquus, and Flammulina velutipes).
Both cellular components and secondary metabolites of
a large number of mushrooms have been shown to effect
the immune system of the host and therefore could be
used to treat a variety of disease states.
|
|
|
|
|
| |
|
|
|
