The effect of immunization with killed tumor cells, with/without feeding of Echinacea purpurea in an erythroleukemic mouse model

Anti-senescence compounds: A potential nutraceutical approach to healthy aging

The desire of eternal youth seems to be as old as mankind. However, the increasing life expectancy experienced by populations in developed countries also involves a significantly increased incidence of the most common age-related diseases (ARDs). Senescent cells (SCs) have been identified as culprits of organismal aging. Their number rises with age and their senescence-associated secretory phenotype fuels the chronic, pro-inflammatory systemic state (inflammaging) that characterizes aging, impairing the regenerative ability of stem cells and increasing the risk of developing ARDs. A variegated class of molecules, including synthetic senolytic compounds and natural compounds contained in food, have been suggested to possess anti-senescence activity. Senolytics are attracting growing interest, and their safety and reliability as anti-senescence drugs are being assessed in human clinical trials. Notably, since SCs spread inflammation at the systemic level through pro-oxidant and pro-inflammatory signals, foods rich in polyphenols, which exert antioxidant and anti-inflammatory actions, have the potential to be harnessed as "anti-senescence foods" in a nutraceutical approach to healthier aging. We discuss the beneficial effects of polyphenol-rich foods in relation to the Mediterranean diet and the dietary habits of long-lived individuals, and examine their ability to modulate bacterial genera in the gut.

Immunity: plants as effective mediators

In the domain of nutrition, exploring the diet-health linkages is major area of research. The outcomes of such interventions led to widespread acceptance of functional and nutraceutical foods; however, augmenting immunity is a major concern of dietary regimens. Indeed, the immune system is incredible arrangement of specific organs and cells that enabled humans to carry out defense against undesired responses. Its proper functionality is essential to maintain the body homeostasis. Array of plants and their components hold immunomodulating properties. Their possible inclusion in diets could explore new therapeutic avenues to enhanced immunity against diseases. The review intended to highlight the importance of garlic (Allium sativum), green tea (Camellia sinensis), ginger (Zingiber officinale), purple coneflower (Echinacea), black cumin (Nigella sativa), licorice (Glycyrrhiza glabra), Astragalus and St. John's wort (Hypericum perforatum) as natural immune boosters. These plants are bestowed with functional ingredients that may provide protection against various menaces. Modes of their actions include boosting and functioning of immune system, activation and suppression of immune specialized cells, interfering in several pathways that eventually led to improvement in immune responses and defense system. In addition, some of these plants carry free radical scavenging and anti-inflammatory activities that are helpful against cancer insurgence. Nevertheless, interaction between drugs and herbs/botanicals should be well investigated before recommended for their safe use, and such information must be disseminated to the allied stakeholders.

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group.

Dietary consumption of Echinacea by mice afflicted with autoimmune (type I) diabetes: effect of consuming the herb on hemopoietic and immune cell dynamics

Epidemiological studies indicate that the incidence of Type 1 diabetes, an autoimmune disease, is rising rapidly. However, none of the current therapies produces life long remission, or can prevent the disease onset. The NOD (non-obese diabetic) mouse is currently regarded as an excellent animal model of human Type 1 diabetes. NKT cells are known to be fundamental in modulating the disease, yet they are numerically and functionally deficient in mammals bearing this disease. Indeed, the role of NK cells in inhibiting autoimmunity in general is well established. Immunoregulatory strategies are currently believed to be the way of the future with respect to modulating autoimmune diseases. Based on this hypothesis, and the fact that the herb, Echinacea, is a well demonstrated immunostimulant of NK cells in normal mice/humans, we aimed to investigate, in NOD mice, the effect of short term (days) and long term (months) daily dietary administration of Echinacea, on the absolute levels of NK cells, and five other classes of hemopoietic and immune cells, in the bone marrow and spleen. The results revealed that, in NOD mice, dietary Echinacea, resulted in a significant increase in the absolute numbers of NK cells, irrespective of feeding duration, in the spleen, and moreover, it actually stimulated NK cell production in their bone marrow birth site. We further found that there were transient, early (days), herb exposure-time-dependent, quantitative changes in several of the other hemopoietic and immune cells populations in both the bone marrow and spleen. We conclude that consumption of this herb by NOD mice, at least, has lead to no negative repercussions with respect to the hemopoietic and immune lineages, and secondly, the consistent, long-lasting immunostimulation only of NK cells, may lead to a possible new approach to the treatment of Type 1 diabetes.

Enhancement of innate and adaptive immune functions by multiple Echinacea species

Echinacea preparations are commonly used as nonspecific immunomodulatory agents. Alcohol extracts from three widely used Echinacea species, Echinacea angustifolia, Echinacea pallida, and Echinacea purpurea, were investigated for immunomodulating properties. The three Echinacea species demonstrated a broad difference in concentrations of individual lipophilic amides and hydrophilic caffeic acid derivatives. Mice were gavaged once a day (for 7 days) with one of the Echinacea extracts (130 mg/kg) or vehicle and immunized with sheep red blood cells (sRBC) 4 days prior to collection of immune cells for multiple immunological assays. The three herb extracts induced similar, but differential, changes in the percentage of immune cell populations and their biological functions, including increased percentages of CD49+ and CD19+ lymphocytes in spleen and natural killer cell cytotoxicity. Antibody response to sRBC was significantly increased equally by extracts of all three Echinacea species. Concanavalin A-stimulated splenocytes from E. angustifolia- and E. pallida-treated mice demonstrated significantly higher T cell proliferation. In addition, the Echinacea treatment significantly altered the cytokine production by mitogen-stimulated splenic cells. The three herbal extracts significantly increased interferon-alpha production, but inhibited the release of tumor necrosis factor-gamma and interleukin (IL)-1beta. Only E. angustifolia- and E. pallida-treated mice demonstrated significantly higher production of IL-4 and increased IL-10 production. Taken together, these findings demonstrated that Echinacea is a wide-spectrum immunomodulator that modulates both innate and adaptive immune responses. In particular, E. angustifolia or E. pallida may have more anti-inflammatory potential.

Enhancement of natural killer cells and increased survival of aging mice fed daily Echinacea root extract from youth

In spite of Echinacea-based products being among the best-selling herbs in the world to date, to allay assorted ailments, the debate is still on-going with respect to the efficacy of ingesting the herb intermittently, continuously, or only at the beginning of an affliction. We sought, therefore, to find out if mice, receiving dietary Echinacea daily, throughout life, from youth until late middle-age, demonstrated any longevity/survival differences, and/or any differences in their various populations of immune/ hemopoietic cells. Sustained and/or high levels of these cells are crucial for longevity. Some mice were maintained on a regular chow diet to which was added Echinacea purpurea daily (2 mg/mouse), from puberty (7 week) until just beyond 13 months of age (late middle-age in mice). Control mice, identically housed and maintained, received identical chow without the herb. Mice consuming untreated diet had a 79% survival by 10 months of age, while those consuming Echinacea daily in the diet were still 100% alive by 10 months. At approximately 13 months of age, mice consuming untreated diet had a 46% survival rate while those consuming Echinacea, were 74% alive at this time. Moreover, the key immune cells, acting as the first line of defense against developing neoplasms in mice and humans, i.e., natural killer (NK) cells, were significantly elevated in absolute number both in their bone marrow production site, as well as in the major organ to which they traffic and function, i.e., the spleen. The cells of the myeloid/granulocyte lineages remained steadfastly at control levels in both the bone marrow and spleen in Echinacea-consuming mice. Thus, it appears that regular intake of Echinacea may indeed be beneficial/prophylactic, if only for the reason that it maintains in an elevated state, NK cells, prime elements in immunosurveillance against spontaneous-developing tumors, a phenomenon which increases in frequency with progressive aging.

Natural health products, modulation of immune function and prevention of chronic diseases

The immune system is increasingly found to be involved in the development of several chronic illnesses, for which allopathic medicine has provided limited tools for treatment and especially prevention. In that context, it appears worthwhile to target the immune system in order to modulate the risk of certain chronic illnesses. Meanwhile, natural health products (NHPs) are generating renewed interest, particularly in the prevention and treatment of several chronic diseases. Over 20 scientists from fields related to immune function and NHPs were thus convened to establish the state of knowledge on these subjects and to explore future research directions. This review summarizes the result of discussions held during the symposium. It thus seeks to be thought provoking rather than to comprehensively cover such broad areas of research. Notably, a brief overview of the immune system is presented, including potentially useful targets and strategies to keep it in an equilibrated state, in order to prevent certain disorders. The pertinence and limitations of targeting the immune system to prevent chronic diseases is also discussed. The paper then discusses the usefulness and limitations of current experimental tools available to study the immune modulating effects of NHPs. Finally, a concise review of some of the most studied NHPs showing promising immunomodulatory activity is given, and avenues for future research are described.

Echinacea: a miracle herb against aging and cancer? Evidence in vivo in mice

Echinacea has been viewed as an immunoenhancing herb since it became commercially available several years ago. Indeed, its medicinal significance is responsible for billions of dollars in worldwide sales annually. Unfortunately, most of the 'evidence' for the purported medicinal efficacy of Echinacea has been anecdotal and, moreover, to this day, there is no formal proof on how to achieve the best results-whether it should be consumed daily throughout life as a prophylactic; consumed by either young or old; or consumed after diseases, such as cancer, have taken hold. Our work over the past 5 years has led to conclusive answers to some of these questions, at least in mice. Our results have shown that daily consumption of Echinacea is indeed prophylactic, extends the life span of aging mice, significantly abates leukemia and extends the life span of leukemic mice. Given that humans are 97% genetically common with mice and that virtually all our basic physiology is identical, it is neither unjustified to extrapolate these observations to humans nor would it be an arduous task to perform many of these studies in humans, thus establishing viable scientific evidence replacing the anecdotal.

Dietary Echinacea purpurea during murine pregnancy: effect on maternal hemopoiesis and fetal growth

BACKGROUND

The medicinal benefits of Echinacea sp. plants in several disease conditions, including insect bites, respiratory ailments, and even cancer and AIDS, have been touted for decades. Echinacea sp.-based phytoceuticals are among the top selling herbals in the Western marketplace today. However, evidence is very scant concerning the effects of using Echinacea species herbals during pregnancy. While available data indicates that fetal malformations do not occur during pregnancy in humans consuming this herb, there are no formal studies aimed at assessing the possibility that consuming Echinacea herbals may promote spontaneous abortions, thereby reducing the number of live births upon which to assess the presence or absence of malformations.

OBJECTIVES

We undertook a study in which pregnant mice were fed daily Echinacea purpurea from pregnancy onset until gestational days 10, 11, 12, 13, and 14.

METHODS

Maternal spleen and bone marrow were taken for enumeration of cells in each of five separate hemopoietic lineages/organ, and fetal status was recorded.

RESULTS

The data indicate that the significant, pregnancy-induced elevation in splenic lymphocytes and nucleated erythroid cells was all but eliminated in those females which consumed E. purpurea daily throughout their pregnancy. Moreover, consuming E. purpurea during pregnancy reduced the number of viable fetuses.

CONCLUSIONS

The data may be extrapolated to suggest that in humans, abstention from consuming Echinacea products during the early/mid stages of pregnancy, may be prudent.

Effect of oral administration of freshly pressed juice of Echinacea purpurea on the number of various subpopulations of B- and T-lymphocytes in healthy volunteers: results of a double-blind, placebo-controlled cross-over study

BACKGROUND

In a recent double-blind placebo-controlled crossover-study the "immune stimulatory" effects (activation of macrophages leading to enhanced phagocytosis and production of several cytokines) of Echinacea purpurea preparations (EPP) which were observed in vitro experiments and following parenteral administration could not be confirmed following oral application of the drug in healthy volunteers. The aim of the present study was to investigate whether or not oral EPP has any effect on important lymphocyte-subpopulations.

SUBJECTS AND METHODS

Forty healthy male volunteers (age range 20-40 years) participated in the study. They received either a commercially available pressed juice of E. purpurea herbs or placebo juice using a double-blind placebo-controlled cross-over design with two treatment periods of 14 days. The total number of lymphocytes and 12 subgroups of lymphocytes were determined by using Flow-cytometry.

RESULTS

After 1 week of treatment with verum the mean value of the total number of lymphocytes decreased slightly (-6%, p = 0.033) compared to the initial value. Treatment for 1 and 2 weeks with EPP had only minor effects on two of the 12 subtypes of lymphocytes. No significant changes were observed in the verum period for the following types of cells: T- and B-lymphocytes, CD4 + - and CD8 + -T-lymphocytes including the subgroups of "naive" and "memory" CD4 + - and CD8 + -T-lymphocytes as well as the natural killer cells. Using a modified version of the Wilcoxon-Mann-Whitney-U-test, which is claimed to be optimal for the evaluation of the results of studies with a cross-over design, a significant difference was found for the number of CD8 + -T-lymphocytes and natural killer cells corresponding to either a decrease during treatment with verum or an increase in the number of these cells in the placebo period.

CONCLUSION

Oral administration of EPP for 1 and 2 weeks has only minor effects on two out of 12 lymphocyte subpopulations determined in the study. The small differences observed in the number of CD8 + -T lymphocytes and natural killer cells are only of questionable physiological relevance.

CAM and NK Cells

It is believed that tumor development, outgrowth and metastasis are under the surveillance of the immune system. Although both innate and acquired immune systems play roles, innate immunity is the spearhead against tumors. Recent studies have revealed the critical role of natural killer (NK) cells in immune surveillance and that NK cell activity is considerably influenced by various agents, such as environmental factors, stress, foods and drugs. Some of these NK cell stimulants have been used in complementary and alternative medicine (CAM) since ancient times. Therefore, the value of CAM should be re-evaluated from this point of view. In this review, we overview the intimate correlation between NK cell functions and CAM agents, and discuss possible underlying mechanisms mediating this. In particular, neuro-immune crosstalk and receptors for CAM agents are the most important and interesting candidates for such mechanisms.

Effect over time of in-vivo administration of the polysaccharide arabinogalactan on immune and hemopoietic cell lineages in murine spleen and bone marrow

Current evidence indicates an immunostimulating role for complex carbohydrates, i.e., polysaccharides, from several plant sources. In the present work, we determined the specific in vivo effects, with time of administration, of one such compound, a neutral arabinogalactan from larch not only on immune (lymphoid) cells, but also on natural killer (NK) lymphoid cells, as well as a variety of other hemopoietic cells in both the bone marrow and spleen of healthy, young adult mice. The latter were injected daily (i.p.) with arabinogalactan (500 microg in 0.1 ml pH 7.2 phosphate buffered saline-PBS) for 7 or 14 days. Additional, aged (1 1/2-2 yr) mice were similarly injected for 14 days only. Control mice were given the PBS vehicle in all cases, following the above injection regimen. Animals from all groups were sampled 24 h after the final injection and the immune and hemopoietic cell populations in the bone marow and spleen were assessed quantitatively. The results indicated that immediately following either 7 or 14 days of arabinogalactan administration to young, adult mice, lymphoid cells in the bone marrow were significantly decreased (p < 0.004; p < 0.001, respectively) relative to controls but remained unchanged at both time intervals in the spleen. NK cells, after 7 days of arabinogalactan exposure, were also decreased significantly in the bone marrow (p < 0.02), but unchanged in the spleen. After 14 days' exposure to the polysaccharide, NK cells in the bone marrow had returned to normal (control) levels, but were increased in the spleen (p < 0.004) to levels greater than 2-fold that of control. Among other hemopoietic cell lineages, none was influenced in the bone marrow or spleen by one-week administration of arabinogalactan; however, after two-week exposure, precursor myeloid cells and their mature (functional) progeny (granulocytes), were significantly reduced in the spleen (p < 0.043; p < 0.006, respectively), as were splenic monocytes (p < 0.001). These lineages in the bone marrow, however, remained steadfastly unaltered even after 14 days of continuous exposure to the agent. Of the vast cascade of cytokines induced in the presence of this polysaccharide, it appears that immunopoiesis- and hemopoiesis-inhibiting ones are most prevalent during at least the first two weeks of daily exposure.