Antibiotic Resistance, Superbugs and Drugs

--- All 200 posts here ---

Antibiotic resistance results, because spontaneous mutations occur so frequently that all bacteria are different.  It is just a matter of exposing enough bacteria to an antibiotic to find one that is insensitive to a particular antibiotic.  More bacteria mean a greater chance of mutations to antibiotic resistance.  The gut contains a lot of bacteria and sewage treatment plants are loaded with gut flora.

Health in Diagrams

Antibiotics are Ubiquitous

All organisms, plants, fungi and animals/humans produce chemicals that kill bacteria, i.e. antibiotics.  I have written many articles about the natural antibiotics of plants, a.k.a. phytoalexins or “antioxidant” polyphenolics, and the human defensins that are peptides with heparin binding domains.  Bacteria also produce viruses, called bacteriophages, that kill other bacteria.  All of these natural antibiotics are small molecules that interact with many different human proteins, and it is these side effects that permit their exploitation as pharmaceuticals.  Thus, statins were selected from fungal antibiotics that inhibited an enzyme needed for human synthesis of cholesterol, metformin was a phytoalexin found to reduce blood sugar and resveratrol is a grape phytoalexin.

Plant Antibiotics are Natural

The flavoring chemicals in herbs and spices have a far more important use in food preparation than titillation of taste buds, since those chemicals kill common food pathogens.  More profoundly, it is important to realize that the selective advantage of phytochemicals/polyphenols/alkaloids/essential oils to the plants that make them, is as natural antibiotics.  Plants kill bacteria, as well as fungi and insects, for a living.

Plant Chemicals Attack all Aspects of Bacteria

Most of the thousand genes that are present in a bacterium code for proteins/enzymes and most antibiotics target those enzymes.  Penicillin binds to an enzyme needed to make bacterial cell walls, streptomycin target protein synthesis, rifampicin blocks RNA synthesis, actinomycin D inhibits DNA synthesis, etc.

Mutation to Antibiotic Resistance is Automatic in Bacteria

Each time a cell replicates, mistakes are made and the new DNA molecule of each chromosome is slightly different than the original.  There are about a thousand genes on the single chromosome of a bacterium and about the same number on each of the 23 human chromosomes.  About a dozen mistakes, mutations, are made each time bacteria replicate.  The mutations that alter the gene target of an antibiotic and produce a bacterial enzyme that is unaffected by the antibiotic, yield an antibiotic resistant bacterium.  The mutant gene now codes for antibiotic resistance and the presence of several resistance genes in the same bacterium produces multiple antibiotic resistant "superbugs."

Mutations are Random, but Antibiotics Select for Resistance

Each cellular replication produces random mutations throughout the bacterial DNA, but of the billion sites along the DNA that can mutate, only a few will produce a modified enzyme that will no longer interact with a particular antibiotic and thus be resistant.  Antibiotic resistance mutants are rare, less than one in a million, but a million bacteria can grow from a single cell in a day and occupy a volume less than a crystal of salt.  Ten hours later, after ten more doublings of the million bacteria, there will be a billion, and there will be a good chance that among those will be a mutant that is resistant to a particular antibiotic.  In the pound of bacteria in the human gut, there are mutants that are resistant to most antibiotics, including the antibiotics that have not yet been developed.  Of course, most of those antibiotic resistant bacteria are just flushed down the toilet.  Treatment with antibiotics kills all of the sensitive bacteria and leaves only the resistant.  Thus, antibiotic treatments select for antibiotic resistant bacteria.

Common Use of Antibiotics Selects for Resistance on Plasmids

Genes are transferred between bacteria by bacteriophages, conjugation (a kind of bacterial sex) and transformation, which is the release of DNA from one bacterium with subsequent uptake by another.  Biofilms, which are communities of many different species of bacteria, stimulate transformation and exploit bacterial DNA as a matrix material to hold the communities together.  The human gut is lined with biofilms and the biofilm bacteria secrete vitamins as the quorum sensing signals that coordinate community activity.  Thus, some vitamins must stimulate transformation, the exchange of DNA among members of the different species of bacteria in the biofilms with evolution of new and novel species.  Rapid change in the gut environment selects for a shift in genes that provide for adaptation to the new environment to small DNA fragments, plasmids, that move most readily between bacteria.  Antibiotic treatment results in antibiotic resistance genes on plasmids.

Use of Multiple Antibiotics Selects for Multiple Antibiotic Resistance Plasmids

Persistent use of an antibiotic will spread resistance to a particular antibiotic through the gut flora, facilitated by antibiotic resistant plasmids.  Replacement of a second antibiotic will result in a new plasmid with both antibiotic resistance genes.  Hospitalization and exposure to a plethora of bacteria with multiple antibiotic resistance plasmids will result in rapid conversion of gut flora to multiple antibiotic resistance upon exposure to any antibiotics.  Hospital staff would be expected to be natural repositories for multiple resistance genes, especially if they are exposed to any antibiotic (or pharmaceutical.)

Most Pharmaceuticals Select for Multiple Antibiotic Resistance Plasmids and Superbugs

The frightening rise of superbugs resistant to all known antibiotics has been attributed to the accelerated use of antibiotics in medicine and agriculture.  Mixing megatons of bacteria in the guts of billions of people with tons of antibiotics, and still more in sewage treatment plants and agriculture, is bound to produce bacteria with every type of multiple antibiotic resistance plasmid imaginable.  But that is not the biggest problem, since fingering the commercial use and misuse of antibiotics ignores biggest exposure of bacteria to antibiotics.  It ignores the fact that most popular pharmaceuticals, NSAIDs, statins, anti-depressants, anti-diabetics, etc., also have substantial antibiotic activity.  Most of these pharmaceuticals started out as phytoalexins and then were found to also have pharmaceutical activity.  Pharmaceuticals are just repurposed natural antibiotics.  When you take an aspirin or Metformin or a statin, you are taking an antibiotic.  When you take a pharmaceutical, you are selecting for multiple antibiotic resistance plasmids in your gut flora and you may be making the next superbug.

Suffering from Inflammation?

How do you know if your symptoms result from inflammation?

My interest is the molecular basis of inflammation, how inflammation is triggered and how inflammation contributes to numerous diseases. I try to expose the inflammatory underpinnings of various diseases by initially linking a disease to inflammation and then unraveling the molecular events that lead to and make up the disease.

How Do I Link a Disease to Inflammation?

My first task is to check the biomedical literature to see if there are research articles that support anti-inflammatory interventions that prevent or limit the disease. I just do a PubMed search the disease name plus anti-inflammatory treatments, e.g. omega-3 fish oils, vitamin D, NSAIDs, etc. It is also possible to see if a disease, such as diabetes, that produces chronic inflammation is a risk factor for the new disease being examined. It is shocking to me that omega-3 fish oils (EPA/DHA) or even flax seed oil, have been found to be effective treatments for numerous diseases that range from allergies, arthritis, inflammatory bowel diseases, depression and even septic shock and multiple organ failure. Aspirin has been used to treat infertility and post partum depression, and at high levels to treat cancer.

Dietary Suppression as Prima Fascia Evidence of Inflammatory Cause

If I find that omega-3 oils have been used successfully to treat a disease, then I attempt to link inflammation to the molecular events that initiate the disease. The biomedical literature is of minimal help here. [Biomedical research is usually limited to assessing the impact of drugs on the symptoms of diseases, so the biomedical literature typically does not provide information on the cause of diseases or ways to cure diseases. Causes and cures do not receive research funding.] I have to learn the basic workings of the organs involved and the alterations of function associated with the disease. I have also found by long experience, that major molecular components are systematically missing from typical explanations of function.

Heparan sulfate/heparin Is Missing in Action

Heparan sulfate proteoglycans (HSPGs) dominate the extracellular environment and yet they are systematically excluded from biomedical research. On this blog, I have provided dozens of examples of the essential role played by HSPGs and disruption of these roles by heparin. The majority of cytokines, growth factors, clotting events, complement cascades and even lipid transport (LDL) act via HSPGs. Leaking of proteins into the urine, across the intestines or the blood brain barrier is controlled by HSPGs, is reduced by inflammation and can be partially repaired by heparin. Autoimmune and allergic diseases are initiated by disruptions in HSPG metabolism. Viral and bacterial pathogens bind to human cells via HSPGs. Cancer cells reduce their HSPGs and start to secrete heparanase in order to metastasize. Mast cells secrete heparin! HSPGs and heparin are major players in tissue function and yet the major cell biology text book does not even discuss them. HSPGs are not mentioned in medical school training even though heparin is the most commonly administered drug.

One of the insights that I bring to my conceptualization of diseases is the role of heparan/heparin in cellular physiology. It explains a lot.

Check for Inflammatory Symptoms by Trying the Anti-Inflammatory Diet

If your symptoms are due to inflammation, there is an easy way to find out. Since diet is the biggest source of inflammation and most of the cells of the immune system congregate in your intestines, it makes sense to check to see your health problems are rooted in inflammation by making simple changes in your diet. Since this is just a test, don’t worry about whether or not this is diet for the rest of your life. Just stick to it for a week and see if it changes your life.

The Basic Anti-Inflammatory Diet and Lifestyle Guidelines are here.

(Vitamin D and omega-3 fish oil amounts are minimal levels. More severe examples of inflammation will require higher levels. Vitamin D up to 10,000 IU per day has been found safe. Some individuals require up to 12 fish oil capsule per day to experience relief from symptoms. Increases should be gradual over weeks of time.)

Try it for a week and let me know if your symptoms disappear. The prevalence of diet-based inflammation, makes me confident that you will be glad that you tried these simple, healthy changes. For immediate relief of pain, see my articles on capsaicin, castor oil and menthol/Vicks.

This is not medical advice and is used only in appropriate support of primary medical care.

Allergy, Asthma, Autoimmunity Start the Same Way

Inflammation is the current medical buzzword. Name the disease and inflammation is there.

Reproduction Requires Controlled Inflammation
Aspirin blocks many of the steps in triggering inflammation and thus, aspirin administration can be used to reveal a role of inflammation in many unexpected places. Aspirin is effective in blocking some forms of infertility, inhibiting miscarriages and ameliorating postpartum depression. So inflammation is a critical part of reproduction. But, also notice that depression is a symptom of chronic inflammation.

Cancer Requires Inflammation
High dose (IV) aspirin has been successfully used to treat cancer. Inflammation is required for cancer growth, because both use the same transcription factor, NFkB. The aberrant signaling of cancer cells would normally lead to programed cell death, apoptosis, but inflammation blocks apoptosis. Aspirin can in turn block NFkB and in the absence of inflammation, cancer cells die by apoptosis.

Inflammation is Self-Limiting
Aspirin also transforms the COX/lipoxidase system to produce anti-inflammatory prostaglandins/eicosinoids. Inflammation normally progresses into anti-inflammation. Blocking this progression leads to chronic inflammation and a shift from local to systemic inflammation with the rise of inflammatory interleukins in the blood stream.

Immune Response Requires Inflammation
The signal molecules (IL-1, IL-6, TNF) and transcription factor, NFkB, associated with inflammation were all initially identified in the development of lymphocytes. Hence, IL stands for interleukin, a hormone that triggers leukocyte (literally white blood cells or cells associated with the lymphatic immune system, i.e. lymphocytes) development. The nuclear factor, i.e. transcription factor, involved in expression of the large chain, kappa, of immunoglobulins in B cells, was called NFkB.

Genes Expressed by NFkB Cause Symptoms of Inflammation
About five dozen genes are under control of NFkB. Among these are COX-2, the enzyme that converts omega-6 arachidonic acid to inflammatory prostaglandins; iNOS, the enzyme that produces nitric oxide that dilates blood vessels to produce hot, red skin; and the inflammatory interleukins, IL-1, IL-6 and TNF, associated with autoimmune disease, fatigue and cachexia (wasting).

Autoimmunity and Allergy Start with Inflammation
Medical treatments focus on symptom abatement and ignore cause. What causes obesity, allergy or autoimmune disease? The answer appears to be chronic systemic inflammation plus exposure to unusual proteins. The unusual proteins are immunogenic, i.e. interact with the immune system to produce antibodies or reactive T-cell receptors, and are subsequently recognized as autoantigens or allergens, that are the targets for immune attack. Inspection of these autoantigens and allergens shows that they all have one thing in common, they bind to heparin via a strong heparin-binding protein domain that is typically a triplet of adjacent basic amino acids.

Heparin is a Short, Highly Sulfated Fragment of Heparan Sulfate
Commercial heparin is purified from the intestines of hogs and cattle. Heparin is released from mast cells (made fluorescent for microscopy using berberine) along with histamine and is released into the intestines to block pathogens from binding to the heparan sulfate that is part of the intestine surface. The heparin is anti-inflammatory and it contributes to minimizing the inflammatory response of the intestines to food.

Inflammation Reduces Heparan Sulfate Production
Pathogen-generated inflammation of the intestines reduces heparan sulfate production and increases immune response to food antigens. NFkB activation by inflammation turns off the production of some genes needed for heparan sulfate proteoglycan (HSPG) synthesis. Since HSPG is a major component of the basement membrane that holds tissues together, the reduction of HSPG results in protein loss (proteinuria) from kidneys, leaking of intestines, and disruption of the blood/brain barrier.

Reduction of HSPG Results in Immunological Presentation of Autoantigens/Allergens
Proteins are brought into cells by specific binding to protein receptors. In many cases, particularly involving signaling or growth factors, both the signal molecules and the receptors bind to heparin. In addition, there is a robust circulation of HSPG, which is secreted and internalized with a half-life of approximately six hours. The sweep of the HSPGs take heparin-binding proteins with them for internalization, e.g. HIV-TAT, heparanase, tissue transglutaminase. I think that this HSPG sweep under inflammatory conditions also internalizes basic autoantigens and allergens with strong heparin-binding domains. This internalization is the first step toward immunological presentation and the immune response to autoantigens and allergens.

Autoantigen/autoantibody/HSPG Complexes Kill Cells
Antibodies against self-antigens, autoantigens form antigen/antibody complexes that also bind to and cross-link HSPGs, because of the heparin-binding domains of the autoantigens. The large complexes may disrupt HSPG circulation and trigger apoptosis or abnormal physiology. There are many other examples of heparin-based complexes that are toxic, e.g. Alzheimer’s amyloid plaque, diabetic beta cell antibody complexes, celiac gluten/tRG antibody complexes, multiple sclerosis myelin antibody complexes, atherosclerotic plaque.

Anti-Inflammatory Diet and Lifestyle Protects
Dietary and lifestyle adjustments that minimize inflammation, e.g. low starch, no HFCS, low vegetable oil (except olive) and supplements of vitamins D & C, fish oil (omega-3) and glucosamine, reduce the risk of allergies/asthma, degenerative diseases and cancers. Simple, high level supplements with fish oil reduce numerous mental disorders, e.g. depression, ADHD; infertility, pre-eclampsia and postpartum depression; allergies, asthma; arthritis, atherosclerosis; burn recovery, septicemia and head injury.

Reducing Inflammation is a Panacea for Modern Diseases
Most modern diseases have an inflammatory component, because modern diets are rich in inflammatory components, e.g. starch/sugar, corn/soy oil, HFCS, trans fats, and exercise is minimal. The medical industry has not successfully promoted healthy eating and exercise; and in fact has promoted the devastating replacement of saturated fats with inflammatory polyunsaturated vegetable oils. Meat production has moved away from grazing on omega-3-rich plant vegetation to omega-6-rich corn and soy. Replacement of the corn/soy based agricultural economy would have predictably immense beneficial impact in reducing inflammation-based degenerative autoimmune diseases and cancers.

Medical Advice Is Just Wrong

Medical advise says to avoid sun, fats and red meat, but to drink lots of water, eat polyunsaturated vegetable oils and focus on the grain-rich bottom of the food pyramid. The medical advice is simply wrong and is not supported by the biomedical literature. A recent article in a major medical journal claims that about 90% of medical advice is not based on clinical research studies, but rather represents the opinions of experts who are supported by the health industry. Most research is conducted to support products. Unfortunately the advice that comes from medical societies is not healthy.

Here I will provide a few examples to illustrate that medical advice is frequently, if not usually, wrong about diet, nutrition, cause of disease, appropriate drug use and whether to spend a few unprotected moments basking in sunshine.

The Sun Is Not the Enemy, but Sun Blockers Can Increase Skin Cancer

Medicine is supposed to provide instructions on how to handle dangerous chemicals and procedures safely and to enhance health. Solar radiation is dangerous and will cause skin cancer if used inappropriately, but solar radiation is also needed to produce vitamin D in skin. The public response to the medical mandate to limit solar exposure to reduce radiation-based skin cancer resulted in increased use of solar-blocking lotions. Unfortunately, the result was that some people spent more time in the sun, assuming that avoiding sun burns meant that they were avoiding skin cancer. Unknowingly they had shifted their skin exposure down from doses sufficient to kill cells and cause inflammation, to levels sufficient to just cause solar mutagenesis -- the lower exposures were optimal for skin cancer production.

Spare the Sun and Spoil the Child

Babies and children are the most sensitive to solar radiation induced skin cancer and need protection from over exposure, but the public response to medical advice has been to avoid prudent exposure to the sun. Now kids in the U.S. are showing symptoms of rickets, a vitamin D deficiency disease common during early industrialization, in which air pollution, urban poverty and factory work limited solar exposure. Babies in strollers are completely covered. One frightening consequence of this over-reaction could be a resurgence of poor bone growth that in the 1920’s resulted in the development of the now-trendy Cesarean section procedure to accommodate women with malformed pelvises due to rickets.

Rickets Is Rampant

Ubiquitous vitamin D deficiencies due to inadequate sun exposure is compounded by inadequate sources of dietary vitamin D and inappropriate medical interventions. Most vitamin D deficiencies go unnoticed, because the typical symptoms of deficiency mimic other forms of inflammation. When serum levels of vitamin D are actually measured and found to be inadequate, supplements of 600-1000 iu/day of vitamin D3 are prescribed. Unfortunately, there is seldom followup testing and a recent study indicates that most treatment for vitamin D deficiencies is inadequate -- much higher doses, ca. 2-5000 iu/day are required to reach optimum levels. Most people are and remain vitamin D deficient.

Scourge of Scurvy

Vitamin C deficiencies are also a problem. Most people get enough vitamin C to avoid losing their teeth (vitamin C is needed for collagen production), but subclinical deficiencies still produce chronic inflammation. The major cellular anti-oxidant is glutathione, but vitamin C is another major defense against reactive oxygen species (ROS). An increase in ROS triggers oxygen stress and inflammation. Deficiency of vitamin C indicates that more vitamin C is being used up than is being replenished in the diet. Numerous metabolic disturbances associated with other deficiencies or infections can result in vitamin C depletion and chronic inflammation. Most people are vitamin C deficient.

Vegetable Oils Are the Problem, Not the Cure

Medical advice to avoid saturated fats in meats and shift to omega-6-rich vegetable oils is a major contributor to chronic inflammation and modern degenerative diseases. The original claimed association between saturated fat consumption and cardiovascular disease was tenuous, but produced a glacial shift in diet toward consumption of omega-6 fatty acids, e.g. corn and soy oils. The medical dependence on measurements and treatments of LDL, has outweighed the actual data in the biomedical literature -- LDL levels are not important in cardiovascular disease. Drugs that lower LDL, serum cholesterol, are only effective in reducing heart disease, if they lower LDL by lowering inflammation. The risk factor is the inflammation, not the LDL level. Agricultural practices that use grain over grass further reduce the omega-3 fatty acid content of meat and increase the inflammatory omega-6 fatty acid level.

Statins Are a Problem, Not the Cure

Statins are broad spectrum disrupters of the function of many different enzymes and proteins. They were originally isolated from fungi based on their ability to poison bacteria, i.e. they are antibiotics. They disrupt fat metabolism and thereby lower LDL levels, but they also cause many undesirable and potentially dangerous side-effects. One of these actions is to block inflammation triggered by activation of the inflammation transcription factor, NFkB. By blocking NFkB activation, some statins lower inflammation and thereby decrease cardiovascular disease. This activity is similar to aspirin, which acts on COX-2 as well as directly on NFkB. Both statins and aspirin (NSAIDs) have multiple activities on numerous areas of cellular metabolism. The activities of both include reduction in inflammation, but they also produce other undesirable side effects. Chronic inflammation is better treated by diet, exercise and traditional herbs and spices, rather than more dangerous statins.

Water Is Miraculous, but just Satisfy Your Thirst

If you are thirsty drink tap water. There is no improvement in health by drinking some extra amount of water each day. Drinking water in plastic bottles from magical sources provides no improvement in health. Much of the “spring water” with designer labels is only locally bottled tap water. The plastic bottles are an ecological disaster and the “purified” water in the bottles is contaminated with compounds leaching from the bottles. If you want a constant source of water, bottle your own tap water. If you want to avoid the minor contaminants added to avoid bacterial contamination of municipal water supplies, use a simple point-of-use filter.

Starch Is the Problem

Starch is rapidly converted into blood glucose and that spike in blood sugar causes major problems. The foundation of the old food pyramid, grains, is no different than table sugar in being hyperglycemic, i.e. rapidly raising blood sugar. A large muscle mass and high physical activity can minimize the rise in blood sugar, by using up the sugar for muscle energy as it enters the blood. Unfortunately, most people do not have enough muscle and are not physically active enough to be protected from the starch and sugars in their diets. The result is chronic inflammation in the form of metabolic syndrome and degenerative diseases, e.g. diabetes, allergies, depression, acne, infertility, cardiovascular disease, autoimmune diseases and cancers.

One slice of white bread with a meal may be too much starch for some people. The maximum for most people is: one half of a ripe banana or one half cup of a starchy entree such as pasta, potato, rice, or one of the two buns on a burger. The starch needs to be spread over several meals. Eating too much starch with a meal produces intense hunger, as the blood sugar rapidly rises, triggers insulin release and a subsequent crash in blood sugar. Don’t believe any of the diets that recommend starches to replace fats. Many “lite” diet foods are more unhealthy than the higher fat originals that they replace. Replacing saturated fats with saturated starch is dangerous. The temporary high blood sugar level produces the increased health risks routinely associated with diabetes.

Insufficient Food Is the Problem -- Insufficient Minerals

It takes only 2-3000 Calories per day to energize most people. That means that most people can eat their day’s worth of calories with the sandwich plate at a fast food restaurant. That meal will provide an overdose of starch and sugar, but will be deficient in vitamins and minerals. A major dilemma is that it takes so little food to provide adequate energy for a low activity lifestyle, that the choice must be made between obesity and vitamin/mineral deficiencies. Eating just enough to satisfy energy needs results in deficiencies, but eating more to avoid vitamin/mineral deficiencies, results in obesity. The only solutions are to eat supplements to supply needed vitamins, minerals, antioxidants, etc. or increase physical activity and body muscle mass, so that more can be eaten without producing obesity. For most people the solution is a combination of increased physical activity and supplements. That combination is also found to reduce inflammation and the associated risk of degenerative diseases.

It’s the Stupid Diet

The obsession of medicine with drugs and invasive procedures provides additional health risks for patients. Many researchers complain in the biomedical literature that there is insufficient focus on the cause of disease and too much emphasis on the study of the impact of specific drugs on disease symptoms. The result is that in most cases the symptoms are treated and the disease becomes chronic. Of course this also means that the patient is a permanent consumer of health care.

The foundation of all healthcare should be to improve the lifestyle of the patient. Diseases don’t just happen. The biggest contributions of immediate family to disease of an individual are not defective genes, but rather defective diet and lifestyle habits. Our healthcare system is too no fault. People are sick because there is something wrong with how they live. They eat too much or they eat the wrong foods. They don’t get enough exercise to develop a healthy muscle system to support their joints. Most importantly, bad diet and lifestyle choices produce chronic inflammation. Drugs can reduce chronic inflammation, but will also produce additional side effects that will also require interventions. It makes more sense to attack the original causes of inflammation.

Every treatment program should address the pervasive contribution of chronic inflammation by including a diet and lifestyle inventory and an assessment of the cause of the disease that is being treated. An appropriate anti-inflammatory diet and a path toward a more active lifestyle should be the foundation of every treatment plan.

Where’s the Aspirin?

Aspirin is the traditional anti-inflammatory agent. Many of us grew up with the quintessential doctoring phrase, “Take two aspirin and call me in the morning.” Aspirin stops inflammation in several ways. Like all drugs, it interacts with many different proteins/enzymes. In fact it interacts so intimately with the inflammatory system that it suggests that the process of inflammation may require an aspirin-like molecule to function normally.

Aspirin Binds to Multiple Enzymes of Inflammation

Aspirin is observed to reduce inflammation. That means that ingested aspirin tablet dissolve in the stomach and pass through the intestines into the blood stream and subsequently bath cells of the blood and the endothelium that lines the blood vessels. In order to reach the blood stream, the aspirin must pass through the intestinal cells. That passage requires binding to a protein transport molecule.

Cells responding to an inflammatory signal (NFkB, transcription factor is activated) synthesize enzymes that release unsaturated fatty acids (ARA, EPA, DHA) from membrane phospholipids (PLA2, phospholipase A2), form a cyclic epoxide from the fatty acid (prostaglandin H2 synthase 2, also called cyclooxygenase 2, COX-2).

Aspirin binds to the inhibitor that normally inactivates NFkB and prevents NFkB activation that is required for inflammation. Aspirin also binds to PLA2 and prevents fatty acid release and thereby blocks activation of inflammation. Aspirin also binds to COX-2 and blocks the production of inflammatory prostaglandins from ARA. But that is not all that aspirin does.

Inflammation Resolution Uses Aspirin-COX-2 Interaction

The strange interaction that makes aspirin suspicious is that aspirin doesn’t just interfere with the action of enzymes, it subtly changes their specificity. Thus aspirin chemically transfers its acetyl group (CH3-COOH-) to an amino acid in the active site of COX-2 to produce a new group of anti-inflammatory lipoxins from ARA, EPA and DHA.

This raises the question of whether aspirin is a natural dietary modulator of inflammation. Recall that aspirin was initially obtained from willow (Salix) bark. Unfortunately, the data are conflicting. Initial research indicated that grains (naturally inflammatory) lacked aspirin, but many herbs, spices and leafy vegetables (naturally anti-inflammatory) contained aspirin. Subsequent tests refuted this work. It would be consistent with observations that some dietary components are anti-inflammatory, but candidate acetyl donors have not been identified.

Speculative acetyl candidates may include the menthol relatives, such as menthyl acetate (figure). Peppermint oil, which contains mostly menthol with some menthyl acetate, is more effective in the treatment of inflammatory bowel disease than most pharmaceuticals prescribed to treat the condition. This anti-inflammatory activity may be due in part to the aspirin-like chemical structure and function of the menthyl acetate. Also note that acetic acid/vinegar is sometimes suggested as a cure-all. This activity may be a consequence of its formation of ester linkages with alcohols that have structures similar to menthol.

Large Dose Aspirin as Cancer Treatment

The potent anti-inflammatory effects of aspirin have been compromised, because inflammation is an essential developmental activity. Thus, the integrity of the gut, for example, requires modest production of inflammatory prostaglandins and a pill of aspirin can disrupt gut tissue. Large doses of aspirin cannot be given orally. Intravenous administration of large doses of aspirin, however, is possible and the impact on process that require inflammation is dramatic.

Anecdotal evidence indicates that large dose aspirin is able to disrupt cancers, because proliferation of cancer cells requires NFkB activation and other inflammatory responses. High doses of aspirin also cause other potentially dangerous complications, such as short-circuiting oxidative phosphorylation of mitochondria and increasing nitric oxide free radical production. Still, the impact of high dose aspirin on some diseases is so amazing that it is being actively and carefully pursued.

Synuclein and Amyloid Diseases

NSAIDs, such as ibuprofen and aspirin are possible treatments to inhibit the aggregation of proteins (synuclein, beta amyloid) on charged polymers in amyloid diseases, such as Parkinson’s disease, Alzheimer’s disease, etc. Contradictory studies show that intracellular aggregate formation may be protective, since dimers are more toxic than aggregates.

The list of amyloid diseases is long and there are few effective treatments. In each case a protein starts to accumulate in fibers that form amyloid plaques inside or outside the cells. The large aggregates outside are toxic. Inside it appears that the large aggregates are not as toxic as small clumps, oligomers, of the protein.

The amyloid proteins are stacked up in the fibers in a very organized way, so that the same portions of the protein are lined up on each side of the fibers. Outside the cell, the regions with basic amino acids interact with heparin, and in Alzheimer’s disease, for example, the beta amyloid plaque is half heparin. In test tube experiments, fiber formation from protein solutions is accelerated by adding heparin.

Amyloid fibers also form inside cells in the case of the tau fibers of Alzheimer’s disease or the synuclein aggregates in Parkinson’s disease. In theses cases, there should not be any intracellular heparin, and it is not known what polyanion (RNA?) serves to accelerate fiber formation in these cases.

Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and aspirin, reduce the incidence of Parkinson’s and Alzheimer’s diseases. It has recently been shown that in test tube experiments, NSAIDs also decrease the formation of amyloid fibers from synuclein.

Amyloid fibers can be stained by Congo Red and thioflavin. Curcumin is the active component of tumeric and it has a structure related to Congo Red. Curcumin has been shown in recent studies to block synuclein amyloid formation.

In addition, the heparin in the fiber complexes can be stained with berberine. Berberine is a traditional herbal treatment for arthritis. It would not be surprising if it was also effective against Alzheimer’s amyloid plaque.

The large extracellular plaque aggregates appear to be toxic, but the small, oligomeric aggregate of protein appear to be the toxic form in cells. Recent experiments show that facilitating the formation of large intracellular aggregates minimizes the toxicity in animal models of Huntington’s and Parkinson’s diseases. It appears that the large visible aggregates are not the form that kills the cell.

For the time being, the only safe treatments that focus on amyloid fiber formation are the NSAIDs, curcumin and perhaps berberine.

references:
Hirohata M, Ono K, Morinaga A, Yamada M. 2008. Non-steroidal anti-inflammatory drugs have potent anti-fibrillogenic and fibril-destabilizing effects for alpha-synuclein fibrils in vitro. Neuropharmacology 54(3):620-7.

Pandey N, Strider J, Nolan WC, Yan SX, Galvin JE. 2008. Curcumin inhibits aggregation of alpha-synuclein. Acta Neuropathol. 115(4):479-89.

Bodner RA, Outeiro TF, Altmann S, Maxwell MM, Cho SH, Hyman BT, McLean PJ, Young AB, Housman DE, Kazantsev AG. 2006. Pharmacological promotion of inclusion formation: a therapeutic approach for Huntington's and Parkinson's diseases. Proc Natl Acad Sci U S A. 103(11):4246-51.

Outeiro TF, Kontopoulos E, Altmann SM, Kufareva I, Strathearn KE, Amore AM, Volk CB, Maxwell MM, Rochet JC, McLean PJ, Young AB, Abagyan R, Feany MB, Hyman BT, Kazantsev AG. 2007. Sirtuin 2 inhibitors rescue alpha-synuclein-mediated toxicity in models of Parkinson's disease. Science. 317(5837):516-9.

Topoisomerase Inhibitors

Inhibiting enzymes involved in DNA synthesis should stop cancer cells, because cancer is uncontrolled cell division. Topoisomerases are enzymes that help to relieve the twists on double helical DNA as it unwinds preparatory to replication. It appears logical that topoisomerase inhibitors should be cancer inhibitors. Unfortunately targeting DNA-binding proteins also targets most of the signal receptors that are the targets for the evolution of plant alkaloids.

Drugs are designed to be specific in their interactions with a particular target protein, but they are too small to be specific and end up binding to many other related proteins. Hence, drugs have side reactions that are to some extent unpredictable, because the interacting proteins are not known.

Aspirin, for example, is supposed to bind to and inhibit COX-2, the enzyme that converts omega-3 and omega-6, long-chain fatty acids into corresponding anti-inflammatory and inflammatory prostaglandins, resp. Aspirin also binds to proteins that inhibit NFkB, the transcription factor that controls expression of inflammatory genes. Aspirin binds to dozens of other proteins. Aspirin does lots of other things than just blunt inflammation, but those side reactions are usually not significant enough to get our attention.

Heparin is one of the most commonly used drugs. It binds to and activates an inhibitor of thrombin, an enzyme that activates fibrin and mediates clotting. Heparin also binds to other components of the clotting system, as well as a dozen components of the complement system, and most of the cytokines that control communications throughout the body. When patients are given heparin injections, heparin binds continually to all of these components and must be constantly supplemented and monitored. Inflammation depletes the heparin components throughout the body, so it is not known prior to injection, how much heparin will be needed to saturate other serum proteins before the desired level of clotting inhibition is achieved. This illustrates rather dramatically that most drugs have only limited specificity.

One of my students provided another example of the minimal specificity of small molecules, especially the alkaloids and phenolics produced by plants. He brought to me a research article espousing the use of phenolics from yerba mate, which serves as a coffee-like stimulant in Argentina, as a topoisomerase inhibitor and potential anti-tumor treatment. Sure enough, phenolics extracted from this plant inhibit topoisomerase, and they may well be able to inhibit the growth of tumors, but it is doubtful that the binding of the phenolics to topoisomerase in the tumor nuclei has anything to do with inhibition of tumor growth.

Topoisomerase binds to nuclear DNA as the DNA unwinds during replication to produce two new double helical DNA molecules. Topoisomerase is a DNA-binding protein, i.e. a protein that binds to a negatively charged polymer of small deoxyribose sugars and flat purine and pyrimidine bases. Proteins bind to DNA in two ways. Amino acids of the protein either bind along the edges of the hydrophobic stack of base pairs, e.g. sequence-specific transcription factors, or they provide hydrophobic, flat surfaces that bind to the hydrophobic faces of the separated bases. Topoisomerase does both, because it deals with single-stranded regions of DNA and therefore binds to both the phosphates, as well as the bases. The important point here is that both aromatic amino acids, with flat hydrophobic rings, and the hydrophobic tails of basic amino acids, i.e. lysine and arginine, bind to the hydrophobic faces of nucleic acid bases.

I have illustrated the binding of a “topoisomerase inhibitor” to show the arginine (blue) in the active site cleft of the topoisomerase that binds across the hydrophobic face of the inhibitor (grey and red). Many plant phenolics and alkaloids would be expected to similarly bind and act as inhibitors of topoisomerase. This observation and the ease by which alkaloids enter cells (attached to circulating heparan sulfate?) suggests that a major function of the nuclear envelope may be to minimize access of alkaloid and related molecules to the nucleic acid binding proteins of the nucleus.

The binding promiscuity of secondary plant products is further exemplified by berberine. Berberine is an alkaloid found in goldenseal and is an herbal remedy used to treat a variety of inflammatory diseases. It also binds to heparin (and nucleic acids) to produce a fluorescent complex. Thus, mast cells that store and secrete histamine and heparin to produce the symptoms of allergy, can be vividly stained with berberine.

I could not resist the temptation to check to see if berberine also binds to topoisomerase. A quick search of the research literature showed that berberine is in fact a topoisomerase inhibitor.

The numerous cross reactions of drugs are further illustrated by metformin, the common drug used in the treatment of type II diabetes. Metformin is approximately planar and provides a surface that cannot hydrogen bond, i.e. it is hydrophobic. I expected that metformin would bind to tryptophans that I observed as common substrate-binding amino acids in the active sites of proteins that bound to polysaccharides, e.g. lectins, glycosidases and glycanases. To test this, I had students in one of my courses examine the inhibitory activity of metformin on E. coli beta-galactosidase. They found measurable inhibition and support for competitive binding to the active site that contains a pair of the predicted tryptophans.

My protein modeling and structural studies show the basis for numerous interactions between plant secondary compounds, drugs, nucleic acids, polysaccharides (glycosaminoglycans, e.g. heparin) and proteins. Unpredicted cross reactions abound and every drug can be expected to interact with multiple proteins. This provides a note of caution to the use of any drug and encourages minimal exposure, since many unobserved and unanticipated side effects are occurring. These observations also question routine ingestion of herbal remedies, after all, plants use their secondary products as potent defenses against being eaten. Alkaloids disrupt nervous systems and cellular signaling. Plants are not naturally safe.