Active hexose correlated compound enhances the immune function of mice in the hindlimb-unloading model of spaceflight conditions

Abstract

Active hexose correlated compound enhances the immune function of mice in the hindlimb-unloading model of spaceflight conditions. J Appl Physiol 97: 1437-1444. First published June 11, 2004 10.1152 10. /japplphysiol.00259.2004 unloading is a ground-based model that simulates some of the aspects of spaceflight conditions, including lack of load bearing on hindlimbs and a fluid shift to the head. It has been shown that treatment with active hexose correlated compound (AHCC) restores resistance to infection in mice maintained under hindlimb-unloading conditions. The present study was designed to clarify the mechanisms by which AHCC enhances resistance to infection in this model. We hypothesized that oral administration of AHCC will enhance the function of the immune system, which could lead to the increased resistance to infection observed in this model. AHCC or the excipient was orally administered to mice, and the function of the immune system was assessed in spleen and peritoneal cells isolated from those groups. The results of the present study showed that administration of AHCC for 1 wk before and throughout the second day of the hindlimb-unloading period enhanced the function of the immune system assessed by spleen cell proliferation and cytokine production in spleens and nitric oxide and cytokine production in peritoneal cells. These findings suggest that AHCC can be used as a potent immunoenhancer, especially in cases in which the immune system is suppressed by any condition, including diseases such as human immunodeficiency virus infection and cancer.antiorthostatic; suspension; stress; mitogens; natural supplement; rodents ONE OF THE MAJOR LIMITATIONS to studying human physiology during and after spaceflight has been the relative infrequency of opportunities and the cost of spaceflight missions. As a result, research in this area has been conducted by using ground-based models (1). Hindlimb unloading of rodents is a ground-based model that has been used successfully to reproduce many of the effects of spaceflight on the physiology of the host (1). Exposure to hindlimb-unloading conditions induces muscle and bone loss and a fluid shift to the head, which are similar to changes induced in that area by spaceflight (20,(33)(34)(35)(36). The immune system is one of the important regulatory mechanisms affected by spaceflight (15, 23, 26, 40 -44, 46) and has been shown to be dramatically affected in groundbased models (14,24,29,30,45).Numerous substances have been used to revitalize the immune response of hosts with impaired function of the immune system (21, 27). Many of them are natural compounds that have proven to be nontoxic for humans and with great potential for anticancer activity (9, 31, 39, 48). Active hexose correlated compound (AHCC), an extract prepared from cocultured mycelia of several species of Basidiomycete mushrooms, has received special attention in the past few years (21). AHCC is commercially used as a nutritional supplement and contain a mixture of polysaccharides, amino acids, and mine...

Effects of active hexose correlated compound on frequency of CD4+ and CD8+ T cells producing interferon-γ and/or tumor necrosis factor–α in healthy adults

“…AHCC has been shown to have an enhancing effect on immune function of humans [2,11] and rodents [9,[12][13][14] including an increase of natural killer (NK) cell activity [15], interleukin-12 production [16,17] and resistance to bacterial infection [7,18]. Of interest, it has been found that the effects of AHCC are more evident in hosts with the impaired immune function [18].…”

Active Hexose Correlated Compound Acts as a Prebiotic and Is Antiinflammatory in Rats with Hapten-Induced Colitis

“…AHCC has been well tolerated both as a human nutritional supplement and as a therapeutic agent (1,5). Furthermore, several studies have proven that the oral administration of AHCC has a wide variety of therapeutic effects, including anticancer effects both in animal models and in clinical trials (2,3,(6)(7)(8), prevention of the onset of diabetes induced by streptozotocin in animal models (9), prevention of liver injury produced by CCl 4 in mice (10), and improvement of the immune response (7,11,12). The anticancer activity of AHCC has been ascribed to its immunomodulatory and antioxidant properties (4,7,13).…”

Inhibition of active lymph pump by simulated microgravity in rats

“…The HDT rat is used as a surrogate for microgravity exposure because this model induces the cephalic fluid shift that occurs in microgravity (10,24,47,59) and HDT rats manifest many of the adaptations that are characteristic of human exposure to microgravity, including hypovolemia (37,51), immune dysfunction (1,8,9,50,52,57), resting and exercise tachycardia (32), a diminished capacity to elevate vascular resistance (32,44), orthostatic hypotension (31), and a reduced aerobic capacity (13,44). Comparative analysis of metabolic and structural shifts in rats after 14 days of microgravity aboard biosatellite Cosmos-2044 and their tail-suspended synchronous controls demonstrated a high correlation of changes in bones and muscles for both experimental groups of animals and provided valuable evidence that HDT can be used as a model of the microgravity effects in ground-based studies (26).…”