Hari D. Khanna

Free Radical Injury and Blood-Brain Barrier Permeability in Hypoxic-Ischemic Encephalopathy

OBJECTIVES. The purpose of this work was to evaluate the extent of free radical injury in newborns with hypoxic ischemic encephalopathy by measuring plasma levels of malondialdehyde and nitric oxide and to assess the blood-brain barrier permeability by measuring the cerebrospinal fluid albumin/plasma albumin ratio. METHODS. This prospective observational study was conducted over a period of 2 years at Sir Sundarlal Hospital, Banaras Hindu University. The study population consisted of 43 term neonates with perinatal asphyxia who subsequently developed hypoxic ischemic encephalopathy. Twenty normal gestational age- and gender-matched healthy infants without any perinatal asphyxia served as control subjects. Peripheral venous blood samples were analyzed for malondialdehyde, total plasma nitrates/nitrites, and albumin levels between 12 and 24 hours of life. To assess the blood-brain barrier permeability, the cerebrospinal fluid albumin/plasma albumin ratio was measured. Correlation among the levels of malondialdehyde, nitrates/nitrites, and blood-brain barrier permeability was calculated. Data were analyzed by using SPSS 10 software. RESULTS. Plasma malondialdehyde and nitrate/nitrite levels were significantly higher in infants with hypoxic ischemic encephalopathy compared with control subjects. Although there was a progressive increment in plasma levels of malondialdehyde with increasing severity of hypoxic ischemic encephalopathy, the differences were not statistically significant. Plasma nitrate/nitrite levels were almost similar in all stages of hypoxic ischemic encephalopathy. Plasma albumin levels were comparable in infants with hypoxic ischemic encephalopathy and control subjects, whereas cerebrospinal fluid albumin levels and blood-brain barrier permeability were significantly higher in infants with hypoxic ischemic encephalopathy. Significant correlation was observed between plasma malondialdehyde and nitrate/nitrite levels with blood-brain barrier permeability. CONCLUSIONS. Increased plasma levels of malondialdehyde and nitrates/nitrites are found to be associated with hypoxic ischemic encephalopathy, indicating the possible role of free radical injury in its causation. Increased blood-brain barrier permeability may be another contributory factor to the progression of the disease.

Evaluation of biomarkers of oxidative stress and antioxidant capacity in the cord blood of preterm low birth weight neonates

Objective: The objective of the study is to investigate the association between oxidative stress markers and enzymatic / non-enzymatic antioxidants (marker of the resistance in body to oxidative damage) in the cord blood of preterm low birth weight (LBW) neonates. Methods: Malondialdehyde (MDA), carbonyl proteins, total antioxidant capacity and Vitamin A, E and C levels in the cord blood were determined by spectrophotometry. Results: Increased lipid peroxidation, protein oxidation with decreased values of vitamin A, E, C and total antioxidant capacity were observed in the preterm LBW newborns. Observations of negative correlation between MDA and protein carbonyl with antioxidants vitamin A, E and C and total antioxidant status points towards the existence of oxidative stress in the preterm LBW newborns. Conclusions: Poor fetal growth affects the development of antioxidant defenses of preterm LBW babies, predisposing them to higher oxidative stress, which in turn may partly account for increased morbidity and mortality in these infants. The presence of an association between oxidative stress biomarkers and enzymatic /non-enzymatic antioxidants in the cord blood of preterm LBW neonates suggest that increased oxidative stress may be the result of changes in the levels of certain enzymatic and non-enzymatic antioxidants due to the cause or the effect of oxidative damage occurring at the molecular level.

Association of oxidative DNA damage, protein oxidation and antioxidant function with oxidative stress induced cellular injury in pre-eclamptic/eclamptic mothers during fetal circulation.

Pre-eclampsia is a devastating multi system syndrome and a major cause of maternal, fetal, neonatal morbidity and mortality. Pre-eclampsia is associated with oxidative stress in the maternal circulation. To have an insight on the effect of pre-eclampsia/eclampsia on the neonates, the study was made to explore the oxidative status by quantification of byproducts generated during protein oxidation and oxidative DNA damage and deficient antioxidant activity in umbilical cord blood of pre-eclamptic/eclamptic mothers during fetal circulation. Umbilical cord blood during delivery from neonates born to 19 pre-eclamptic mothers, 14 eclamptic mothers and 18 normotensive mothers (uncomplicated pregnancy) as control cases was collected. 8-OHdG (8-hydroxy-2-deoxyguanosine), protein carbonyl, nitrite, catalase, non-enzymatic antioxidants (vitamin A, E, C), total antioxidant status and iron status were determined. Significant elevation in the levels of 8-OHdG, protein carbonyl, nitrite and iron along with decreased levels of catalase, vitamin A, E, C, total antioxidant status were observed in the umbilical cord blood of pre-eclamptic and eclamptic pregnancies. These parameters might be influential variables for the risk of free radical damage in infants born to pre-eclamptic/eclamptic pregnancies. Increased oxidative stress causes oxidation of DNA and protein which alters antioxidant function. Excess iron level and decreased unsaturated iron binding capacity may be the important factor associated with oxidative stress and contribute in the pathogenesis of pre-eclampsia/eclampsia which is reflected in fetal circulation.

In vivo Oxidative DNA Damage and lipid Peroxidation as a Biomarker of Oxidative Stress in Preterm Low-Birthweight Infants

OBJECTIVES To analyze the status of oxidative stress in relation to the degree of prematurity and birthweight of neonates. MATERIALS AND METHODS Umbilical cord blood samples were obtained at the time of delivery. 8-Hydroxy-2-deoxy guanosine (8-OHdG) has been measured as oxidative DNA damage marker in preterm low-birthweight (LBW) newborns by competitive in vitro enzyme-linked immunosorbent assay (ELISA) along with malondialdehyde (MDA) as marker of lipid peroxidation and total antioxidant status to study the oxidative stress. RESULTS Significant elevation in the levels of 8-OHdG along with malondialdehyde has been noted in preterm LBW newborns. Serum 8-OHdG is found to be significantly and negatively correlated with birthweight (r = -0.834, p < 0.001) and gestational age of the newborn (r = -0.626, p < 0.001). CONCLUSION These results provide evidence of increased oxidative stress in the form of DNA damage and lipid peroxidation in premature LBW newborns, which may be responsible for different complications associated with prematurity.

Vascular Endothelial Growth Factor Levels in Relation to Oxidative Damage and Antioxidant Status in Patients with Breast Cancer

Purpose Oxidative stress and angiogenesis are important elements in the pathogenesis of inflammatory diseases and cancer. Vascular endothelial growth factor (VEGF) is one of the most potent angiogenic cytokines and is up-regulated by conditions associated with the generation of free radicals and reactive oxygen intermediates. In this study, we investigated the association between oxidative stress and serum VEGF status in patients with breast cancer. Methods Forty patients with breast carcinoma, of which 21 were stage II and 19 were stage III, along with 40 age- and gender-matched healthy controls were enrolled. Oxidative stress, total antioxidant status, and VEGF levels in serum were evaluated by spectrophotometric procedures. Malondialdehyde (MDA) levels were measured and antioxidant status was assessed by measuring total antioxidant status (TAS) to assess oxidative damage. Results VEGF and MDA levels were significantly higher in patients with breast cancer than those of controls (p<0.005). Total antioxidant level decreased significantly in patients compared to that in controls. MDA, TAS, and VEGF levels were also analyzed based on menopausal status and different clinical disease stages. MDA and TAS level significantly different in the postmenopausal group than the premenopausal group, whereas VEGF level remained unchanged. Conclusion Increased VEGF level and its positive correlation with oxidative stress level and decreased antioxidant status suggest a link between oxidative stress and malignant transformation.

A novel approach to study oxidative stress in neonatal respiratory distress syndrome

Background Respiratory distress syndrome of the neonate (neonatal RDS) is still an important problem in treatment of preterm infants. It is accompanied by inflammatory processes with free radical generation and oxidative stress. The aim of study was to determine the role of oxidative stress in the development of neonatal RDS. Methods Markers of oxidative stress and antioxidant activity in umbilical cord blood were studied in infants with neonatal respiratory distress syndrome with reference to healthy newborns. Results Status of markers of oxidative stress (malondialdehyde, protein carbonyl and 8-hydroxy-2-deoxy guanosine) showed a significant increase with depleted levels of total antioxidant capacity in neonatal RDS when compared to healthy newborns. Conclusion The study provides convincing evidence of oxidative damage and diminished antioxidant defenses in newborns with RDS. Neonatal RDS is characterized by damage of lipid, protein and DNA, which indicates the augmentation of oxidative stress. General significance The identification of the potential biomarker of oxidative stress consists of a promising strategy to study the pathophysiology of neonatal RDS.

Correlation of serum toll like receptor 9 and trace elements with lipid peroxidation in the patients of breast diseases.

Toll-like receptors are recognized as redox sensitive receptor proteins and have been implicated in cellular response to oxidative stress. Altered pro-oxidant-antioxidant balance leads to an increased oxidative damage and consequently play an important role in breast diseases. The study was designed to access the oxidative stress status by quantification of byproducts generated during lipid peroxidation and inadequate trace elements during oxidative damage and its effects on the toll like receptor (TLR) activity in patients of breast diseases. Decreased levels of selenium, copper, zinc, magnesium and iron with elevated levels of malondialdehyde (marker of lipid peroxidation) were accompanied by decreased TLR activity in patients of benign breast diseases as well as breast carcinoma. A similar pattern was observed with the advancement of disease and its subsequent progression in breast carcinoma patients. Results of multinomial regression analysis suggest benign breast disease patients are at higher risk of developing breast cancer with high odds ratio of lipid damage.

Simultaneous progression of oxidative stress, angiogenesis, and cell proliferation in prostate carcinoma

OBJECTIVES To understand the association between markers of oxidative stress, levels of vascular endothelial growth factor (VEGF), and cell proliferation index in relation to disease progression, clinical stage, and cytologic grade in pathophysiology of prostate carcinoma. PATIENTS AND METHODS Case control study comprised of 40 prostate carcinoma patients along with 40 age- and sex-matched healthy subjects as controls. Levels of 8-hydroxy-2-deoxy guanosine, protein carbonyl, and malondialdehyde along with total antioxidant status were measured to study the oxidative stress status in the study subjects. Angiogenesis was evaluated by studying the VEGF level and cell proliferation index. RESULTS The levels of markers of oxidative stress along with VEGF and cell proliferation index were found to be significantly higher with significantly decreased levels of antioxidant activity in the study subjects in comparison with healthy controls. The results indicate oxidative stress, angiogenesis, and cell proliferation activity increase progressively with the increase in staging and progression of disease. CONCLUSIONS Oxidative stress parameters, angiogenesis, and cell proliferation activity point clearly that with the progression of oxidative stress there is a simultaneous progression of angiogenesis, regulation and control of endothelial cell proliferation in relation to disease progression, clinical stage, and cytologic grade in the pathophysiology of prostate carcinoma.

Protein Damage and Antioxidant Status Alterations Caused by Oxidative Injury in Chronic Myeloid Leukemia

Objective: To evaluate the oxidative stress and antioxidant defense in patients with chronic myeloid leukemia. Background: Chronic myeloid leukemia is a myeloproliferative disorder associated with a characteristic chromosomal translocation called the Philadelphia chromosome. Reactive oxygen species and other free radicals mediate phenotypic and genotypic changes leading from mutation to neoplasia in all cancers, including chronic myeloid leukemia. We evaluated patients with chronic myeloid leukemia by observing their oxidative status and antioxidant defense. Methods: Using serum from 40 clinically diagnosed cases of chronic myeloid leukemia as well as 40 healthy controls, we measured the concentration of thiobarbituric acid, levels of protein carbonylation, total antioxidant status, catalase, superoxide dismutase, glutathione peroxidase, vitamins A and E, and the trace elements zinc, magnesium, and selenium. Results: We found significantly increased levels of serum malonyldialdehyde and protein carbonyl in patients with chronic myeloid leukemia in comparison to healthy individuals, and significantly decreased levels of the antioxidants and micronutrients thiobarbituric acid, catalase, superoxide dismutase, glutathione peroxidase, vitamins A and E, zinc, magnesium, and selenium. These data suggest cellular damage occurring at the level of lipids and proteins. Conclusion: These findings indicate a link between low levels of antioxidants and cellular damage in patients with chronic myeloid leukemia, supporting the idea that oxidative stress may play a role in the pathogenesis of chronic myeloid leukemia.

Docking, Synthesis and Evaluation of Antioxidant Activity of 2,4,5-Triaryl Imidazole

A series of nitrogen-containing heterocyclic compounds such as substituted 2,4,5-triaryl imidazole were synthesized by benzyl, ammonium acetate and aromatic/heteroaromatic aldehyde, evaluated for their antioxidant activity by DPPH method. Among the screened compounds, electron rich imidazole exhibited significant antioxidant activities.