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Antibiotic-Resistant "Super Bugs" on Rise
by Jim English and Ward Dean, MD
Colds and flu are upper respiratory viral infections
that are relatively harmless when compared to the growing threat
of antibiotic-resistant 'super bugs'. The long term effects of antibiotic
overuse are beginning to hit home. And with the emergence of new
and more virulent strains of flu, AIDS, and other immune disorders,
we may be at the limits of what antibiotics can deliver.
Once considered exotic and found primarily in
hospitals, antibiotic-resistant pathogens are rapidly becoming evident
in commonplace settings. Following decades of over-prescribing and
misuse, researchers and scientists now face the end of the 'Golden
Age' of antibiotics. Antibiotic resistance appears 'to be on the
verge of desperation,' said Nobel laureate Joshua Lederberg, who
chaired an Institute of Medicine panel that met last May to discuss
global efforts to fight the growing problem.
Among the growing strains of resistant pathogens
that are emerging:
Staphylococcus epidermidis
is a bacteriim found primarily in skin tissue. Once considered
a non-threatening contaminant, it is now a leading cause of hospital-acquired
bloodstream infection. More than 80 percent of Staphylococcus
epidermidis found in US hospitals is now methicillin resistant.
Recent studies have found S. epidermidis to be resistant
to quinolones, cephalosporins and vancomycin.
Drug-resistant Streptococcus pneumoniae
(DRSP) is a growing threat. Streptococcus pneumoniae
infections — including pneumonia, sinusitis, meningitis
and otitis media — are a leading cause of death and illness
among the elderly, young children and persons with underlying
medical conditions. Penicillin, the most often used antibiotic,
will no longer work on 40 percent of S. pneumoniae cases.
Staphylococcus aureus, a common
cause of skin infections, endocarditis (heart valve infection),
osteomyelitis (bone infection) and sepsis (blood stream infection),
first evidenced signs of resistance to the drug methicillin in
the 1960s. Since then S. aureus strains have shown resistance
to penicillins, macrolides, fluoroquinolones and lincosamides.
Vancomycin-resistant enterococci (VRE)
is a major cause of hospital-acquired infection. VRE has become
resistant to virtually all antibiotics, including vancomycin.
The result of these changes is that doctors now
have to work harder to fight these infections while researchers
race to develop new antibiotics. Although new agents, such as Synercid¨
(quinupristin / dalfopristin), are slowly being developed, the genie
may be out of the bottle for good. Bacteria are extremely capable
of adapting to new antimicrobial weapons. Without drastic controls
on how antibiotics are used, new strains will continue to evolve,
at a rate faster than science can match.
Humans lived for millions of years without pharmaceutical antibiotics.
Pharmaceutical antibiotics were introduced into medicine in the
1930s to 1940s. Prior to that time, physicians and their patients
relied primarily on antimicrobial substances like colloidal silver,
antispetics like alcohol and hydrogen peroxide, and various plant
extracts which stimulated the body's own defense mechanisms. This
latter approach - that of stimulating the body's defenses - is rarely
considered today in 'orthodox' medicine. Although there are few
immune-stimulating pharmaceutical drugs available today, there is
a number of immune-enhancing nutrients and herbs that can dramatically
energize a flagging immune system, and help overcome an attack by
bacteria and viruses.
Herbs have been used for centuries in virtually every culture in
the world. Native American medicine relied heavily on the use of
herbs, and traditional herbal remedies are still commonly prescribed
in Eastern countries such as China, Korea, and Japan as well as
Europe. Over time, trial and error led to the development of folk
medicines, and the most effective remedies were passed down through
the generations. Herbs have been used in an attempt to treat nearly
every known affliction and disease, with mixed results.
While some herbs have been shown to be ineffective,
others have stood the tests of time and research, proving their
worth. The following examples point out how nature has provided
us with safe, effective methods of improving our health and quality
of life.
In traditional Chinese herbal medicine Astragalus is believed to
promote and enhance the immune system, replenish the 'defensive
energy' and accelerate wound healing.1-3 A. membranaceus, the form
of Astragalus used for medicinal purposes, is believed to enhance
immune function by altering the metabolism of immune cells. Studies
in both humans and laboratory animals have demonstrated a potent
antiviral potential via its ability to protect against infection
from the viruses that cause influenza and the common cold. Both
oral and nasal administration of Astragalus extracts have offered
protection against the common cold. In patients who are susceptible
to colds and flu, treatment with Astragalus for short periods of
time (two weeks) enhanced interferon induction by the white blood
cells, resulting in increased levels of cytokines (such as interleukin-2
and IgA and IgG).
Astragalus treatment leads to an increase in T-helper
cell activity. This increase in immune function was clearly demonstrated
in one study where immuno-deficient and healthy normal mice were
treated with Astragalus extract.3 This effect has been noted in
humans as well. When mononuclear cells from cancer patients and
healthy volunteers were inoculated with extracts of Astragalus,
not only did T cell levels rise to levels similar to that of healthy
cells (prior to treatment), T cell levels in cells from healthy
individuals were also significantly increased.
Echinacea, an herb native to North America, has played an important
role in Native American medicine. It was used by numerous tribes
to treat a variety of symptoms and diseases, including: sore mouth
and gums, toothache and coughs, and as an anti-inflammatory and
antiseptic agent.4
More recently Echinacea has been closely examined
for its influence on immune cell proliferation, antibody production,
and antiviral activities.5 One of the most popular uses of Echinacea
is for support and recovery from the common cold and influenza.
Two recent studies support the use of Echinacea for this purpose.
In the first study, 108 patients with colds received
either Echinacea or placebo for eight weeks.6 Of those patients
receiving the Echinacea, 35.2% recovered and remained healthy, while
only 25.9% of the placebo group remained healthy. When the patients
did become infected, the length of time between infections was 40
days for the Echinacea group vs. only 25 days for placebo. When
infection did occur in patients receiving Echinacea, effects were
less severe and resolved quicker. Patients showing evidence of weakened
immune system (CD4/CD8 ratio) benefited the most from Echinacea.
In a second study, 180 patients with influenza
were given either an E. purpurea Echinacea extract or a placebo.
The group receiving Echinacea showed significant reduction of cold
symptoms.7
Additional human studies have shown similar immune
system activity. For example, patients with inoperable liver cancer,
following treatment with echinacea, experienced a dramatic reduction
in the side effects associated with chemotherapy and an enhanced
quality of life, improved immune function, and a significant rise
in natural killer cell activity with CD4 levels.8 Some of these
protective effects are mediated by the increase in cytokine production,
such as increased levels of tumor necrosis factor-alpha (TNF-a)
and interleukin-1 (IL-1).
In addition to its immunosupportive actions, Echinacea
has also demonstrated mild antibacterial activity, due largely to
echinacoside, a complex caffeic acid derivative found in high concentrations
in the root of E. angustifolia. Echinacoside has been shown to have
antibacterial action against Staphylococcus aureus, Corynebacterium
diphtheria, and Proteus vulgaris.1,9,10
Cat's Claw ( Unicaria tomentosa ), a woody vine that grows in Peru,
is a traditional phytomedicinal of the Ashaninka Indians. The Ashaninkas
drink a tea made of the bark once every week or two for general
health. In the event of an illness, they consume about a liter every
day until all symptoms have disappeared.
Both the root and the bark of Cat's Claw, a liana
growing to 100 feet or more, are sources of a rich variety of pharmacologically
active compounds. Among some of the compounds found in U. tomentosa
are catechins, alkaloids, ellagic acid and other phenolic antioxidants
which are beneficial in the treatment of specific types of cancer.
The most immunologically active alkaloids, the oxindole alkaloids,
isopteropodine and pteropodine, have been found by Dr. Klaus Keplinger,
an Austrian researcher, to stimulate immune function. In addition,
the presence of glycosides, proanthocyanidins and beta sitosterol
help provide anti-viral, anti-tumor and anti-inflammatory support
for the body.
Ginseng has been used for centuries in China, Japan, Korea, and
parts of the former Soviet Union for its supportive role in maintaining
health. As an adaptogen, Ginseng is believed to produce a state
of increased resistance to stress, supporting our ability to resist
disease by building up our general vitality and strengthening our
normal body functions.
Soviet researchers have been particularly keen
on ginseng and have claimed their studies show the herb and its
extracts can boost immunity, inhibit cancer, increase energy and
physical stamina and have variable effects on blood pressure and
blood sugar.
A recent study found that ginseng helps prevent
symptoms of the common cold and improves antibody response to influenza
vaccine. For 12 weeks, 227 volunteers who visited three private
medical practices in Milan received daily oral capsule doses of
either 100 mg of a standard Ginseng extract or a placebo. During
the fourth week they received an influenza vaccination. There were
only 15 cases of influenza or common cold in the group receiving
the ginseng extract, versus 42 cases in the group receiving the
placebo. By the eighth week, antibody titers rose to an average
272 units in the ginseng group, versus only 171 units in the placebo
group. Additionally, at both the eighth and twelfth weeks, natural
killer cell activity was nearly twice as high in the Ginseng group
versus the placebo group.11
Infectious diseases are a growing threat worldwide. Recent studies
have shown how antioxidants may play an important role in the treatment
of viral diseases.
Antioxidants not only reduce disease symptoms,
but may also reduce the long-term effects of chronic oxidative stress,
which has been linked to the development of cancer from some viral
infections. Oxidative stress is seen in individuals infected with
influenza, immunodeficiency virus and hepatitis.12
Vitamin C has seemingly been at the center of nutritional research,
particularly with regard to the common cold. It is well known that
Vitamin C is a powerful antioxidant, and this protective activity
is now proving vital in recovery from infection. A number of studies
have found that, during infection there is a marked decrease in
vitamin C levels in plasma and white blood cells. The concentration
of vitamin C in phagocytes and lymphocytes is over 10 times greater
than in plasma, and low intake of vitamin C has been shown to decrease
phagocytic activity in animal models.
Other studies have shown that higher vitamin C
concentration increases the proliferative responses of T lymphocytes
in vitro. Vitamin C has also been reported to induce the production
of interferon in cell culture, and one study has found a correlation
between natural killer cell activity and vitamin C concentration
in leukocytes. Under in vitro conditions, vitamin C has been found
to inactivate viruses and bacteria. In human studies doses higher
than 100 g per day have been used for severe bacterial and viral
infections.13
In a recent study, Italian researchers found that
2 grams per day of ascorbic acid (vitamin C) was effective in restoring
bronchial responsiveness in hospital workers suffering from upper
respiratory infections. The authors suggest that ascorbic acid can
effectively re-establish the redux state in inflamed airways and
may prove beneficial for treatment of coughs during upper respiratory
infection.14
Vitamin E is the body's premier fat-soluble antioxidant, and complement
of vitamin C, the premier water-soluble antioxidant. Vitamin E is
the major protective antioxidant for cell membranes, the dynamic
matrices on and in which most of the body's metabolic activity occurs.
Just as vitamin E protects serum lipoproteins
and regulates prostaglandin balance, new research suggests that
vitamin E supplementation may enhance phagocytosis, cell-mediated
immunity, humoral immunity, and reduce the effects of stress on
the immune response. 15
In an animal study on heart disease in the elderly,
aged mice were fed vitamin E at 500 parts per million 2 months before
exposure to influenza. These animals were found to have substantially
lower amounts of the influenza virus in their lungs than control
mice given smaller amounts at 30 parts per million.16
A related study on age and immune response involved
47 subjects, aged 61 to 79 years. Researchers reported that those
receiving a supplement containing vitamin E and other micronutrients
showed a significant increase in immune response. Specifically,
an increase in CD57 natural killer cells, T cells and T cell subsets.
Conversely, in the placebo group there was a decrease in T cells,
CD4 cells and the CD4:CD8 ratio. Researchers concluded that nutritional
intervention provided an effective approach for delaying the overall
decline in immune function noted with increasing age.17
Vitamin A is one of the best documented nutrients for supporting
immune function. A deficiency in vitamin A is known to reduce resistance
to infection by lowering neutrophil phagocytosis, cell-mediated
immunity, humoral response and interleukin II production. Recent
research has found a strong link between vitamin A intake and upper
respiratory infections.
One 1996 study of newborn infants recorded substantial
decreases in upper respiratory infection in newborns given 50,000
IU of vitamin A versus a placebo. Researchers concluded that neonatal
vitamin A supplementation reduces infant mortality rates, as well
as lessens the severity of respiratory infection.18
A second study linking vitamin A intake and respiratory
infection followed 28,000 children between six months and six years
of age. Higher intake of vitamin A was strongly associated with
fewer upper respiratory infections, lessened incidence of diarrhea
and a reduction in cough and fever. Of notice, there was a significant
positive association with vitamin A intake and the lowered incidence
of cough alone, a sign of a healthy respiratory epithelium.19
N-Acetyl Cysteine (NAC) has been extensively researched for its
antioxidant properties, particularly in its potential to neutralize
the chemical by-products of smoking. NAC has been used for bronchial
congestion for over thirty years, and is used to fight chronic lung
diseases because of its ability to break up mucus. However, one
of the most exciting areas of NAC research is in the area of immunology.
NAC has been found to significantly enhance human T-cell function,
especially in older individuals. NAC is currently undergoing clinical
trials around the world as an augmenter of immune function in people
with AIDS. Its ease of conversion to both extracellular and intracellular
glutathione, coupled with its stability and long half-life in the
body, makes it an economical and powerful antioxidant.
Selenium plays a vital role in immune support. A deficiency of selenium
results in depressed immune function, whereas selenium supplementation
augments and restores proper immune system function. Selenium helps
with the development of all white blood cells. In one study, individuals
with normal selenium blood concentrations received 200 micrograms
per day. This alone resulted in an 118 percent increase in the ability
of lymphocytes to kill tumor cells and an 82.3 percent increase
in the activity of a white blood cell known as a 'natural killer
cell' because of its powerful ability to kill cancer cells and microorganisms.
For over 2000 years Reishi mushrooms ( Ganoderma lucidum ) have
been recognized by Chinese medical professionals as a valuable remedy.
As the 'Medicine of Kings', Reishi is widely used for different
purposes. It is used for symptomatic relief of arthritis and of
menopausal anxiety. It is also used in treating allergic asthma,
hypertension, hypothyroidism, bronchitis, insomnia, general anxiety
and stress, and cardiovascular problems. Reishi also is often the
main ingredient in herbal formulas for immune dysfunction syndromes,
such as Chronic Fatigue Syndrome.
Reishi is prescribed in China for a number of
psychiatric and neurological afflictions, including diseases involving
the muscles, anorexia, and debility following lengthy illnesses.
In an eight-month study of Alzheimer's disease in Japan, patients
taking a Reishi mycelium product demonstrated significant improvement.
Recently, Russian scientists have taken an interest
in Reishi. They found that in addition to the cardiovascular benefits
mentioned above, Reishi showed a significant preventive and therapeutic
action against plaque build-up ('Plaque' is a fatty compound which
is comprised of a combination of oxidized cholesterol, calcium,
and degenerated white blood cells ['foam cells']. It is deposited
on the walls of arteries which restricts blood flow by narrowing
the passage within arteries resulting in arteriosclerosis).
In 1990, researchers at the University of Texas
Health Science Center in San Antonio found that Reishi could be
effectively used in treating stiff necks, stiff shoulders, conjunctivitis
(inflammation of the fine membrane lining the eye and eyelids),
bronchitis, rheumatism, and improving 'competence' of the immune
system without any significant side-effects.
References
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2. Sun Y, Hersh E., Talpaz M, et al. Immune restoration and/or augmentation
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3. Zhang Z, Wen Q, Liu C. Hepatoprotective effects of astragalus
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5. Tyler VE. Report on the 41st Annual Congress of Medicinal Plant
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