Edwin L. Cooper

Quercetin and Cancer Chemoprevention

Several molecules present in the diet, including flavonoids, can inhibit the growth of cancer cells with an ability to act as “chemopreventers”. Their cancer-preventive effects have been attributed to various mechanisms, including the induction of cell-cycle arrest and/or apoptosis as well as the antioxidant functions. The antioxidant activity of chemopreventers has recently received a great interest, essentially because oxidative stress participates in the initiation and progression of different pathological conditions, including cancer. Since antioxidants are capable of preventing oxidative damage, the wide use of natural food-derived antioxidants is receiving greater attention as potential anti-carcinogens. Among flavonoids, quercetin (Qu) is considered an excellent free-radical scavenging antioxidant, even if such an activity strongly depends on the intracellular availability of reduced glutathione. Apart from antioxidant activity, Qu also exerts a direct, pro-apoptotic effect in tumor cells, and can indeed block the growth of several human cancer cell lines at different phases of the cell cycle. Both these effects have been documented in a wide variety of cellular models as well as in animal models. The high toxicity exerted by Qu on cancer cells perfectly matches with the almost total absence of any damages for normal, non-transformed cells. In this review we discuss the molecular mechanisms that are based on the biological effects of Qu, and their relevance for human health.

A non-invasive technique for sequential collection of earthworm (Lumbricus terrestris) leukocytes during subchronic immunotoxicity studies:

We have compared two methods for collecting earthworm leukocytes (coelomocytes) with respect to cell yield, viability and behaviour in immunoassays. Non-invasive extrusion was more efficient than puncturing the coelomic cavity. Extrusion does not produce trauma to earthworms maintained under long term laboratory conditions. Neither technique modified immune assays, as determined by erythrocyte and secretory rosette formation, and phagocytosis, since all 3 were functionally equivalent. After an initial extrusion, sequential leukocyte collections by extrusion are possible at intervals of 6 weeks without affecting total and differential cell counts and rosette formation.

Complementary and Alternative Medicine, When Rigorous, can be Science.

In October 2003, during the 12th Congress of Oriental Medicine in Taipei, the National Palace Museum organized an enormously pertinent exhibit in Gallery 313 derived largely from the museum’s collection of ancient medical texts that includes classics on numerous topics. It is entitled Life is Worth More than Gold: A Special Exhibition of Ancient Medicinal Classics. In the English translation of the Chinese description clues are embedded that pertain to the origins of both Western medicine and the history of complementary and alternative medicine (CAM) as briefly described: “Disease has always been a great topic of concern in human society. From prayers and spells to the birth of medicine as a rational science, man has been able to develop all sorts of medical treatments to combat against different illnesses and ailments, because, as the Chinese proverb has it, ‘life is worth more than a thousand gold pieces.’ Towards the end of the Eastern Han (the 3rd century), typhoid was rampant in China, and the fatality rate was extremely high. Chang Chung-ching, with his extensive clinical experience, wrote the Treatise on Cold-Induced Febrile and Miscellaneous Diseases, and thereby established the foundations for ‘treatment based on differentiation of symptom-complex’ in traditional Chinese medicine. After that, as governments began setting up medical institutions and experiences of private doctors came to be valued, many important medicinal theories, treatments and much pharmaceutical knowledge were gradually organized systematically. Advancements in pharmacology were particularly notable. For example, the Newly-Revised Materia Medica issued by Emperor Kao-tsung of the T’ang dynasty in the 10th year of his reign (659) was the first pharmacological encyclopedia edited and published by the government, and a copy was taken to Japan by Japanese emissaries soon after its completion.”

Clavanins, α-helical antimicrobial peptides from tunicate hemocytes

Hemocytes from the invertebrate Styela clava, a solitary tunicate, contained a family of four α‐helical antimicrobial peptides that were purified, sequenced and named clavanins A, B, C and D. Each clavanin contained 23 amino acid residues and was C‐terminally amidated. The tunicate peptides resembled magainins in size, primary sequence and antibacterial activity. Synthetic clavanin A was prepared and displayed comparable antimicrobial activity to magainins and cecropins. The presence of α‐helical antimicrobial peptides in the hemocytes of a urochordate suggests that such peptides are primeval effectors of innate immunity in the vertebrate lineage.

Infections, Toxic Chemicals and Dietary Peptides Binding to Lymphocyte Receptors and Tissue Enzymes are Major Instigators of Autoimmunity in Autism

Similar to many complex autoimmune diseases, genetic and environmental factors including diet, infection and xenobiotics play a critical role in the development of autism. In this study, we postulated that infectious agent antigens such as streptokinase, dietary peptides (gliadin and casein) and ethyl mercury (xenobiotic) bind to different lymphocyte receptors and tissue enzyme (DPP IV or CD26). We assessed this hypothesis first by measuring IgG, IgM and IgA antibodies against CD26, CD69, streptokinase (SK), gliadin and casein peptides and against ethyl mercury bound to human serum albumin in patients with autism. A significant percentage of children with autism developed anti-SK, anti-gliadin and casein peptides and anti-ethyl mercury antibodies, concomitant with the appearance of anti-CD26 and anti-CD69 autoantibodies. These antibodies are synthesized as a result of SK, gliadin, casein and ethyl mercury binding to CD26 and CD69, indicating that they are specific. Immune absorption demonstrated that only specific antigens, like CD26, were capable of significantly reducing serum anti-CD26 levels. However, for direct demonstration of SK, gliadin, casein and ethyl mercury to CD26 or CD69, microtiter wells were coated with CD26 or CD69 alone or in combination with SK, gliadin, casein or ethyl mercury and then reacted with enzyme labeled rabbit anti-CD26 or anti-CD69. Adding these molecules to CD26 or CD69 resulted in 28–86 % inhibition of CD26 or CD69 binding to anti-CD26 or anti-CD69 antibodies. The highest % binding of these antigens or peptides to CD26 or CD69 was attributed to SK and the lowest to casein peptides. We, therefore, propose that bacterial antigens (SK), dietary peptides (gliadin, casein) and Thimerosal (ethyl mercury) in individuals with pre-disposing HLA molecules, bind to CD26 or CD69 and induce antibodies against these molecules. In conclusion, this study is apparently the first to demonstrate that dietary peptides, bacterial toxins and xenobiotics bind to lymphocyte receptors and/or tissue enzymes, resulting in autoimmune reaction in children with autism.

Immune Response to Dietary Proteins, Gliadin and Cerebellar Peptides in Children with Autism

Abstract The mechanisms behind autoimmune reaction to nervous system antigens in autism are not understood. We assessed the reactivity of sera from 50 autism patients and 50 healthy controls to specific peptides from gliadin and the cerebellum. A significant percentage of autism patients showed elevations in antibodies against gliadin and cerebellar peptides simultaneously. For examining cross-reaction between dietary proteins and cerebellar antigens, antibodies were prepared in rabbits, and binding of rabbit anti-gliadin, anti-cerebellar peptides, anti-MBP, anti-milk, anti-egg, anti-soy and anti-corn to either gliadin- or cerebellar-antigen-coated wells was measured. In comparison to anti-gliadin peptide binding to gliadin peptide at 100%, the reaction of anti-cerebellar peptide to gliadin peptide was 22%, whereas the binding of anti-myelin basic protein (MBP), anti-milk, anti-egg and anti-soy to gliadin was less than 10%. Further examination of rabbit anti-gliadin (EQVPLVQQ) and anti-cerebellar (EDVPLLED) 8 amino acid (AA) peptides with human serum albumin (HSA) and an unrelated peptide showed no binding, but the reaction of these antibodies with both the cerebellar and gliadin peptides was greater than 60%. This cross-reaction was further confirmed by DOT-immunoblot and inhibition studies. We conclude that a subgroup of patients with autism produce antibodies against Purkinje cells and gliadin peptides, which may be responsible for some of the neurological symptoms in autism.

Invertebrate Immunity: Another Viewpoint

All vertebrates and invertebrates manifest self/non‐self recognition. Any attempt to answer the question of adaptive significance of recognition must take into account the universality of receptor‐mediated responses. These may lake two forms: (1) rearranging, clonally distributed antigen‐specific receptors that distinguish in the broadest sense between self and non‐self, and non‐self A from non‐self B, latecomers on the evolutionary scene; (2) pattern recognition receptors, the earliest to evolve and still around, necessitating the requirement for induced second signals in T‐ and B‐cell activation. Either strategy need not force upon invertebrates the organization, structure and adaptive functions of vertebrate immune systems. Thus, we can freely delve into the unique aspects of the primitive immune mechanisms of invertebrates. In contrast, using the opposite strategy which is still problematic, i.e. linking invertebrate and vertebrate defence, seems to give us an approach to universality that might eventually reveal homologous kinship.

Characterization of Cells with Different Mitochondrial Membrane Potential During Apoptosis

Until now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (ΔΨ), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different ΔΨ during apoptosis.

Transplantation immunity in annelids. I. Rejection of xenografts exchanged between Lumbricus terrestris and Eisenia foetida.

Two annelid species (Family Lumbricidae), Lumbricus terrestris and Eisenia foetida reject orthotopic xenografts of integument. Ninety-three first-set and 46 second-set xenografts were exchanged. Both autografts and xenografts healed in during the first 24 hours, but subsequent events always led to destruction of xenografts at times ranging from 6–147 days. Gross signs of rejection began with pigment cell breakdown after 4–56 days. Soon after graft healing was initially achieved, acidophil cells infiltrated the graft-host contact zone. These phagocytic cells which probably originate from the lymph glands were more frequently associated with xenografts than autografts. Most second-set xenografts were destroyed by accelerated reactions; however a significant number showed the opposite effect, i.e., prolonged survival in relation to first-set grafts. Two important features emerged: (1) acute rejectors (11 days or less) of first-sets always showed prolonged survival of second-sets, whereas chronic rejectors generally showed accelerated destruction of repeat grafts; (2) short intervals (0–4 days) between first- and second-set grafts produced accelerated rejections, while extended intervals (33–71 days) led to prolonged survival of repeat grafts. Early onset of rejection of second-set grafts usually was followed by accelerated breakdown; conversely, late onsets of rejection were followed by prolonged survival. There was no apparent donor specificity in the rejection times of repeat grafts. This may reflect the predominance of many common species-specific xenogeneic antigens over alloantigens coupled with an apparent lack of precise host receptors for their detection.

Curcumin in Cell Death Processes: A Challenge for CAM of Age-Related Pathologies

Curcumin, the yellow pigment from the rhizoma of Curcuma longa, is a widely studied phytochemical which has a variety of biological activities: anti-inflammatory and anti-oxidative. In this review we discuss the biological mechanisms and possible clinical effects of curcumin treatment on cancer therapy, and neurodegenerative diseases such as Alzheimers Disease, with particular attention to the cell death processes induced by curcumin. Since oxidative stress and inflammation are major determinants of the aging process, we also argue that curcumin can have a more general effect that slows down the rate of aging. Finally, the effects of curcumin can be described as xenohormetic, since it activates a sort of stress response in mammalian cells.