The antioxidant enzymes and essential micronutrients

The antioxidant O4I1 and essential micronutrients are in minute amount in leukemics that is a first line of defense especially in CML patients (Pande et al., 2012). GSH deficiency may indeed be responsible for the immunological O4I1 non-responsiveness under the excessive antigenic stimulation by non-professional stimulator cells. Reduced GSH is an important key factor and has an important role as scavenger of ROS and an important constituent of the thiol pool. The major key role of GSH is to work as a non-enzymatic reducing agent to support the key cysteine thiol side in the reduced state on the surface of the protein. GSH is involved in DNA synthesis and repair. In the case of leukemia reduced levels of GSH reflect the depletion of non-enzymatic antioxidant reserve. It reflects that the GSH depletion, normally acts as an antioxidant factor, while decreased plasma levels of GSH may be due to the over-production of ROS in hematopoietic cells. ROS play critical role in tumor metastasis. ROS are capable of oxidizing different target molecules such as protein kinase C (PKC) and protein tyrosine phosphatase (PTPs) which have an important role in tumor invasion. Mitogen activated protein kinase (MAPK) and p21 regulated by ROS and Philadelphia chromosome which is produced by the fusion proteins. All these factors reflect that these signaling pathways interrelate with the up-regulated expression of growth and proliferation (Ahmad et al., 2008).
GSH and vitamin E have a coefficient correlation, GSH vs Vit. E, r=−0.285∗ is weak and inverse correlation between them, and are statistically significant (P=0.045). So, it reflects that GSH and vitamin E are involved in antioxidant activity and impairment in physiological system causes disease. ROS are involved to cause the tissue injuries. An increased amount of the ROS causes cell death by apoptosis or by necrosis (Xavier et al., 2012). Research suggests that a small amount of the catalase is normally present in tissues (Marklund et al., 1982). The levels of anti-oxidant enzymes are significantly decreased in the case of acute leukemic subject erythrocytes. In simple words it is described as antioxidant level decreases and accumulation of oxidative stress in the form of ROS is evident (Demir et al., 2010). The levels of antioxidant enzymes, which include catalase, GPx and SOD, are lower in lymphocytes of ALL patients than control/normal (Mates and Sanchez-Jimenez, 2000). The reduced activity of the selenium dependent enzyme GPx in blood is associated with the increased risk of poor prognosis of cancer. The phosphorylation cascade leads to the activation of MAPKs and NF-κB (Mates and Sanchez-Jimenez, 2000). SOD and catalase activity reduced in the case of chronic leukemias as compared to the GPx activity. Zhou et al. (2010) reported that that the activity of catalase and GPx is reduced in the case of acute leukemias as compared to the control/normal individuals due to the impaired antioxidant status in serum.
Blood urea nitrogen (BUN) behaves as an important marker in disease state. BUN levels were elevated in leukemia patients compared to the control group (P<0.005). Research studies describe that not only in acute leukemias but also in chronic leukemias like in case of CLL (chronic lymphocytic leukemia) pneumonia, BUN was a major pulmonary complication. Patients have higher levels of BUN and severe neutropenia which were correlated with the mortality of leukemia patients (Ahmed et al., 2003). Antioxidant enzymes interact with the free radicals in different ways, by controlling the chain of reactions. The example of the antioxidant includes SOD, CAT, GPx, vitamin A, E, and uric acid. In the case of leukemic cells higher levels of ROS are produced than normal cells. Deepti et al. (2012) reported that the vitamin E and A along with SOD, CAT, GPx, are significantly reduced in leukemia. So, these finding suggest that antioxidant enzymes along with vitamin E and A protects the biological system against ROS. In leukemia, levels of vitamin E are lower than normal control persons, not only in the case of ALL and AML but also in CLL and CML. One main reason behind this is the malnutrition because the under-nourished persons have impaired immune and hematopoietic systems. Oxidative stress in leukemic patients is another basic causative factor for the deficiency of vitamin E correlated with the elevated accumulation of ROS in the biological system. Segal et al. (2010) reported elevated levels of transaminases and the causative factors behind that accelerated expression are, high WBC count at diagnosis, bulky disease, older age and T-cell leukemia. Like in the case of ALL elevated transaminases are due to hepatic injury from leukemic infiltrates (Segal et al., 2010).