Mamdooh Ghoneum

T cell profiles in vitiligo

The purpose of our investigation was to quantitatively assess T cell profiles in vitiligo and to correlate any aberrations in these findings with the spectrum of clinical disease. Twenty randomly selected vitiligo patients and sixteen healthy matched control subjects were studied. The immunofluorescence and complement-mediated cytotoxicity assays were used to determine the percentages of total T (OKT3), helper (OKT4), and suppressor (OKT8) cells in the peripheral blood of patients and controls. Both assays gave comparable results. Patients with vitiligo had a statistically significant decrease in helper cells and helper/suppressor ratios in comparison with control subjects (p less than 0.01). In addition, there was a statistically significant decrease in helper cells among patients with a disease duration of less than 1 year (p less than 0.01) and in patients who produced serum autoantibodies (p less than 0.05). These findings tend to suggest that aberrations in cell-mediated immunity may be operative in the pathogenesis of vitiligo.

Augmentation of Macrophage Phagocytosis by Modified Arabinoxylan Rice Bran (MGN-3/Biobran)

MGN-3/Biobran, modified arabinoxylan rice bran, has been shown to be a potent biological response modifier (BRM) as manifested by stimulation of different arms of the immune system such as NK, T and B cells; however, its effect on macrophages has not yet been studied. The effects of MGN-3 on macrophage function was examined in vitro using 3 models: human macrophage cell line U937, murine macrophage cell line RAW264.7, and murine peritoneal macrophages (P-Mφ). Treatment with MGN-3 resulted in an increase in the percentages of attachment and phagocytosis of yeast by macrophages. The effect depends on the type of macrophage and the dose of MGN-3 applied. Macrophages also demonstrated enhancement in their spreading ability, post treatment with MGN-3. Results also showed that MGN-3, in a dose-dependent manner (1, 10,100 μg/ml), significantly induced high levels of production of cytokines: TNF-α and IL-6. In addition, MGN-3 significantly increased nitric oxide (NO) production. This data demonstrates that MGN-3 is a potent inducer of phagocytic function by macrophage, and may suggest that MGN-3 is a useful agent for fighting microbial infection.

Enhancement of natural killer cell activity of aged mice by modified arabinoxylan rice bran (MGN‐3/Biobran)

The present study is aimed to examine the possibility of enhancement of natural killer (NK) cell activity in aged C57BL/6 and C3H mice using MGN‐3, a modified arabinoxylan from rice bran. Intraperitoneal injection of MGN‐3 (10 mg kg−1 per day) caused a remarkable increase in the peritoneal NK activity as early as 2 days (35.2 lytic units), and the level remained elevated through day 14. The control aged mice had a level of 5.8 lytic units. Enhancement in NK activity was associated with an increase in both the binding capacity of NK cells to tumour targets and in the granular content as measured by BLT‐esterase activity. Treatment did not alter the percentage of peritoneal NK cells. Data showed that peritoneal macrophages inhibit NK activity. In conclusion, MGN‐3 enhances murine NK activity of aged mice and may be useful for enhancing NK function in aged humans.

Modified arabinoxylan rice bran (MGN-3/Biobran) sensitizes human T cell leukemia cells to death receptor (CD95)-induced apoptosis

MGN-3, an arabinoxylan extracted from rice bran that is treated enzymatically with an extract from Shiitaki mushrooms, is an effective biological response modifier that increases NK cell activity, and potentiates the activity of conventional chemotherapeutic agents. In this study, we investigated the effect of MGN-3 on death receptor-induced apoptosis in the human leukemic HUT 78 cell line. HUT 78 cells were pre-treated with MGN-3, and then were incubated with the agonistic antibody against death receptor (Fas, CD95). Apoptosis was determined by the propidium iodide technique using FACScan. Activation of caspase 3, caspase 8, and caspase 9 was determined by flow cytometry. Mitochondrial membrane potential was measured with DIOC(6) dye using FACScan. Expression of CD95 and Bcl-2 were measured by flow cytometry. In a dose-dependent manner, MGN-3 enhanced anti-CD95 antibody-induced apoptosis. Increased cell death was correlated with increased depolarization of mitochondrial membrane potential and increased activation of caspase 3, caspase 8, and caspase 9. MGN-3 treatment had no effect on the level of expression of CD95, but it caused down regulation of Bcl-2 expression. These results suggest that MGN-3 increases the susceptibility of cancer cells to undergo apoptosis mediated by death ligands, which may be relevant for anti-cancer activities.

Antioxidant potential by arabinoxylan rice bran, MGN-3/biobran, represents a mechanism for its oncostatic effect against murine solid Ehrlich carcinoma

We have recently examined the oncolytic effect of arabinoxylan rice bran, MGN-3/biobran, against solid Ehrlich carcinoma (SEC)-bearing mice via immune-modulation and apoptosis [N.K. Badr El-din, E. Noaman, M. Ghoneum, In vivo tumor inhibitory effects of nutritional rice bran supplement MGN-3/biobran on Ehrlich carcinoma-bearing mice, Nutr. Cancer 60 (2) (2008) 235-244]. In the present study, we examined the antioxidant system as another possible mechanism through which MGN-3 exerts its oncostatic potential. Female albino mice were inoculated intramuscularly in the right thigh with Ehrlich ascites carcinoma (EAC) cells. MGN-3 (25 mg/kg body weight) was injected intraperitoneally (i.p.) six times a week for 25 days into mice at either day 4 or day 11 post-EAC cell inoculation. Tumor growth, lipid peroxidation (LPx), glutathione (GSH) contents, the activity of the antioxidant scavenger enzymes, and alterations in gene expression were examined. MGN-3 efficiently suppressed the growth of tumors, which was associated with normalization of the LPx levels and augmentation of GSH contents. MGN-3 enhanced the activity of the endogenous antioxidant scavenging enzymes -- superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione-S-transferase (GST) -- in blood, liver, and tumor tissue. Similarly it up-regulated the expression of GPx, SOD1 and CAT mRNA in the liver. The effect of MGN-3 was more pronounced when treated early, at day 4 of tumor cell inoculation, as compared to later treatment at 11 days. In conclusion, MGN-3-induced oncostatic activity by modulating lipid peroxidation, augmenting the antioxidant defense system and protecting against oxidative stress.

Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA.

Abstract. Vojdani A, Ghoneum M, Choppa PC, Magtoto L, Lapp CW (Immunosciences Laboratory Inc., Beverly Hills, and Charles Drew University School of Medicine and Science, Los Angeles, California, and the Hunter‐Hopkins Centre, Charlotte, North Carolina, USA). Elevated apoptotic cell population in patients with chronic fatigue syn‐drome: the pivotal role of protein kinase RNA. J Intern Med 1997; 242: 465478.

Suppression of natural cytotoxic cell activity by social aggressiveness in Tilapia

Our earlier observations revealed that social stress causes drastic effects on different physiological mechanisms and degenerative changes in leucocytes. In this preliminary work, we analyzed the effect of social aggressiveness on functional activities of leucocytes emphasizing (NCC) activity in Tilapia. At 10 hr post stress induction, fish could be differentiated into three categories: 1) dominants; 2) subordinates; and 3) indeterminants. Results of NCC as indicated by 4 hr. 51Cr-release assay, demonstrated a significant suppression in cytotoxic reactivity in the subordinates and indeterminants compared to dominants. This suppression appears to be due to a decrease in the binding capacity of effector cells to YAC-1 target cells as indicated by the decreased number of conjugate forming cells. This binding process is a key event in activating the fish equivalent of NK cells in mammals. Decreased NCC-activity in stressed fish suggests that aberrations in cell mediated immunity result from social aggressiveness.

Suppression of murine natural killer cell activity by tributyltin: In vivo and in vitro assessment

The effects of tributyltin chloride (TBTCl) and inorganic tin (IT) on murine natural killer (NK) cell activity were tested in vivo and in vitro. In vivo studies demonstrated that mice fed with TBT (10 and 100 ppm) daily for 1 week exhibited suppression in NK activity 38-46% at effector:target (E:T) ratio = 50:1 compared to control mice. On the other hand, animals treated with inorganic tin showed no change in activity of NK cells. In vitro studies showed leukocytes, preincubated with TBTCl (0.01-0.1 ppm) at room temperature for 1 h and then washed three times, demonstrated significant suppression in NK activity (41 and 85%) at concentrations 0.01 and 0.05 ppm, respectively. Increasing the dose to 0.1 ppm, resulted in complete inhibition of the activity of NK cells. In contrast, IT had no effect on NK activity in vitro at the same concentrations of TBTCl. The effect of TBTCl appears to be due to interference with the binding capacity of effector cells, a necessary prerequisite for target cell lysis. In conclusion, TBTCl proved to be a very potent inhibitor of NK activity; this inhibition may predispose animals to malignancy, which is a characteristic feature reported recently for some TBT compounds.

In Vivo Tumor Inhibitory Effects of Nutritional Rice Bran Supplement MGN-3/Biobran on Ehrlich Carcinoma-Bearing Mice*

This study was undertaken to investigate the in vivo anti-tumor activity of MGN-3/Biobran, a modified arabinoxylan rice bran. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich ascites carcinoma (EAC) cells. On Day 8, mice bearing a solid Ehrlich carcinoma (SEC) tumor were treated with MGN-3 via intraperitoneal injection. Tumor growth, cytokine production, and apoptotic effect of MGN-3 were examined. MGN-3 caused a highly significant delay in both tumor volume (63.27%) and tumor weight (45.2%) as compared to controls (P < 0.01). The mechanisms by which MGN-3 exerts its antitumor effect seem to involve its ability to induce apoptosis and immune modulation. MGN-3 induced a 1.8-fold increase in the percentage of apoptotic SEC cells as determined by flow cytometry and the histopathological examination. In addition, MGN-3 influenced plasma cytokine production by increasing the levels of tumor necrosis factor-α and interferon-γ, while downregulating levels of the immune suppressing cytokine interleukin-10. Data also showed that non-tumor-bearing mice intramuscularly injected with MGN-3 resulted in a twofold increase in natural killer activity. No adverse side effects due to MGN-3 treatment were observed; all animals displayed normal feeding/drinking and life activity patterns. These data may have clinical implications for the treatment of solid cancers.

MGN-3/Biobran, modified arabinoxylan from rice bran, sensitizes human breast cancer cells to chemotherapeutic agent, daunorubicin

BACKGROUND MGN-3/Biobran, a modified form of arabinoxylan from rice bran, is a potent biological response modifier (BRM). Our previous studies demonstrated that MGN-3 sensitizes human leukemia cells to death receptor [CD95]-induced apoptosis [Ghoneum M, Gollapudi S. MGN-3 sensitizes human T cell leukemia cells to death receptor (CD95)-induced apoptosis. Cancer Lett 2003;201:41-9]. In this study, we evaluated the chemo-sensitizing activity of MGN-3 against human breast cancer cells (BCCs) in vitro. METHODS BCCs (MCF-7 and HCC70 cells) were cultured with different concentrations of daunorubicin (DNR) (from 1x10(-9) to 1x10(-6)M) in the presence or absence of selected concentrations of MGN-3 (100-1000mug/ml) for 3 days. Cancer cell survival was determined by MTT assay and drug accumulation was determined by flow cytometry. RESULTS Treatment with MGN-3 increased susceptibility of BCCs to DNR (5.5-fold for MCF-7 and 2.5-fold for HCC70 cells) as compared to BCCs treated with DNR alone. The sensitizing effect of MGN-3 was associated with increased accumulation of DNR in cancer cells. CONCLUSIONS Our data demonstrate that MGN-3 is an effective chemo-sensitizer and may represent a potential novel adjuvant for the treatment of breast cancer.