Antioxidant potential by arabinoxylan rice bran, MGN-3/biobran, represents a mechanism for its oncostatic effect against murine solid Ehrlich carcinoma
Eman Noaman(a), , , Nariman K. Badr El-Din(b), Mona A. Bibars(c), Ahlam A. Abou Mossallamc and Mamdooh Ghoneum(d)
aDepartment of Radiation Biology, National Center for Radiation Research and Technology, Cairo, Egypt bDepartment of Zoology, Faculty of Science, University of Mansoura, Mansoura, Egypt cDepartment of Cell Biology, Genetic Engineering Division, National Research Center, Cairo, Egypt dDepartment of Otolaryngology, Charles Drew University of Medicine and Science, 1621 E. 120th Street, Los Angeles, CA 90059, USA
Received 22 February 2008; revised 9 April 2008; accepted 10 April 2008. Available online 12 June 2008.
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.