Assessment of oxidative stress and antioxidant status in age related cataract in a rural population

Oxidative stress was assesed by estimating lipid peroxidation product (LPO) in the form of thiobarbituric acid reactive substances (TBARS), enzymatic antioxidants in the form of superoxide dismutase (SOD), catalase and nonenzymatic antioxidant vitamins e.g. vitamin C, β carotene and vitamin E in either serum or plasma or erythrocytes in 190 cases of age related cataract in the age group of 50–80 years. 190 cases were grouped into three morphological types namely, 73 cases of cortical, 77 cases of posterior subcapsular and 40 cases of nuclear cataract and values of LPO and antioxidants were compared with 78 cases of age matched healthy control groups. Plasma TBARS levels were cataract cases when compared with control groups. There were no significant differences in the erythrocyte levels of catalase and plasma levels of Vit E between cataract cases and control groups. No significant changes of parameters were seen among three different morphological types of age related cataract. The present study shows that the oxidative stress may play an important role in the age related cataract.     

Effect of vitamin E supplementation on oxidative stress in hemodialysis patients

Hemodialysis represents a chronic stress status for its recipients. Many hypotheses state that this may be associated with oxidative stress. Thus, there may be deficiency of antioxidants like erythrocytic superoxide dismutase, catalase, vitamin E or increased generation of free radicals like superoxide anions. A study was carried out to investigate oxidant and antioxidant status in chronic renal failure patients undergoing hemodialysis and effect of vitamin E supplementation on these two status. Blood samples were collected from patients before and after hemodialysis and from controls. The samples were analyzed for quantitation of MDA as index of lipid peroxide, nitric oxide, vitamin E, vitamin C and enzymatic antioxidants namely erythrocyte SOD and catalase. As compared to controls, the levels of serum MDA were significantly increased and activities of erythrocyte SOD and catalase, levels of serum nitric oxide, serum vitamin E and plasma vitamin C were significantly decreased both before and after hemodialysis. The efficiency of vitamin E therapy in hemodialysis patients was assessed by re-evaluating oxidant and antioxidant status of same patients after supplementation of vitamin E. Vitamin E supplementation caused decrease in serum MDA and increase in levels of serum nitric oxide, vitamin E, vitamin C and activities of erythrocytic SOD and catalase. Our results suggest the presence of oxidative stress and the possible preventive role of vitamin E therapy in hemodialysis patients.     

Effect of oral antioxidant supplementation on lipid peroxidation during radiotherapy in head and neck malignancies

The objectives of the present study were to ascertain the variations in the serum levels of malondialdehyde and total antioxidant status, in head and neck malignancies with different stages, with and without oral antioxidant supplementation, before and after radiotherapy, and to validate the protective effects of an antioxidant supplementation during radiotherapy. The pretreatment values of serum malondialdehyde were significantly raised, while that of serum total antioxidant status were significantly declined in all the stages of head and neck malignancies, when compared with the healthy controls values (P<0.001). A significant correlation was observed related to the studied parameters and different stages of the disease. The study suggests that an oral antioxidant supplementation during radiotherapy is an effective mode in reducing oxidative stress. Antioxidant supplementation during radiotherapy may serve as an adjuvant therapy in malignancies offering a protection to normal cells that may further reduce the risk of developing secondary cancers.     

Can serum Glutathione-S-transferase levels in carcinoma cervix be a predictor of radiation response?

We conducted a pilot study wherein serum Glutathione-S-transferase levels were measured before and after radiotherapy in carcinoma cervix patients and correlated with response to treatment during a two-year follow-up period. Out of 17 patients who received radiotherapy, 9 showed a significant decrease (p<0.005) while 8 showed significant increase (p<0.004) in post radiotherapy glutathione-S-transferase values as compared to pre treatment values respectively. These patients were followed up for two years and we observed that 71% who had significant increase in post radiotherapy values had relapse of cancer within 2 years where as 66% of those who had significant decrease in post radiotherapy values had no evidence of relapse. This shows that alterations in serum Glutathione-S-transferase levels may help us to predict radiation response     

Role of oxidative stress and antioxidants in aetiopathogenesis and management of oral submucous fibrosis

Lipid peroxidation product, malonaldehyde (MDA) and antioxidants were estimated in plasma and erythrocytes of 34 cases of oral submucous fibrosis (OSMF) of different grades with equal number of healthy controls to evaluate the association of reactive oxygen species (ROS) and OSMF. While plasma MDA was found to be significantly higher in patients (3.3±0.4 nmole/ml, P<0.001) as compared to controls (2.4±0.5 nmole/ml), plasma beta carotene and vitamin E levels were found to be decreased significantly in patients (81.7±14.3 μg/100 ml, P<0.001; 9.3±0.9 mg/L, P<0.01 respectively) with respect to healthy controls (110±20.8 μg/100 ml and 10.1±1.2 mg/L). The decrease in beta-carotene and vitamin E was found to be more significant in OSMF grade II and III than in grade I. After 6 weeks of oral administration of beta-carotene and vitamin E, patients showed increase in plasma level of these two antioxidants along with decrease in MDA level associated with clinical improvement.     

Effect of supplementation of vitamin C and E on oxidative stress in osteoporosis

Osteoporosis encompasses a wide spectrum of conditions associated with imbalance of osteoclastic and osteoblastic activities. The increased activity of osteoclasts leads to increased free radical formation and hence lipid peroxidation. Present study probes into the role of antioxidants as a palliative treatment for osteoporosis. It involved 50 healthy controls and 75 clinically diagnosed osteoporosis patients. Both the groups underwent baseline assessment of biochemical markers viz. osteoblastic markers: serum Alkaline phosphatase. Free or ionic calcium and Inorganic phosphorus, osteoclastic markers: serum Tartarate resistant acid phosphatase and Malondialdehyde and the antioxidant status: serum Superoxide dismutase and Erythrocyte reduced glutathione. The osteoporotic group was then divided into groups A (Vitamin E-Evinal 400 mg), B (Vitamin C-Celin 500 mg), C (Vitamin E+C-Evinal+Celin) for antioxidant supplementation for a period of 90 days. The results reveal that there is significant fall in concentration of serum MDA (p<0.001), TrACP (p<0.01). Improvement in antioxidant status is reflected by significant rise in concentration of serum SOD (p<0.001) and erythrocyte GSH (p<0.001) after 90 days of antioxidant supplementation in osteoporosis. The findings indicate that on the whole bone status improved with prolonged antioxidant vitamin supplementation, which can be used as a palliative treatment for osteoporosis. The efficacy is not affected whether the vitamins are administered singly or conjointly.     

Effect of herbal hypoglycemic agents on oxidative stress and antioxidant status in diabetic rats

In the present study the antioxidative potential ofMomordica charantia, Azadirachta indica, Allium sativum andOcimum sanctum was assessed in streptozotocin induced diabetic rats. Lipid peroxide levels were also measured in normal, diabetic and treated animals. Malondialdehyde (MDA) levels were significantly higher and antioxidant activity was found low in diabetic groups as compared to the control groups, and significant alteration in both the MDA levels and antioxidant activity was also observed when the above herbal hypoglycemic agents were given to diabetic rats. On the basis of our results we conclude thatM. charantia, A. indica, A. sativum andO. sanctum are not only useful in controlling the lipid peroxide levels but are also helpful in further strengthening the antioxidant potential.     

Evaluation of oxidative stress and antioxidant status of pregnant women suffering from malaria in Cameroon

Oxidative stress is thought to be involved in the pathophysiology of malaria, especially in pregnancy where natural resistance is markedly reduced. In the present study we investigated oxidative stress in 315 pregnant women out of which 159 had Plasmodium falciparum malaria and 154 controls. We evaluated the level of lipid peroxidation products (MDA level) in the plasma, the activity of erythrocyte antioxidant defense enzymes, superoxide dismutase (SOD, EC: 1.15.1.1) and catalase (Cat, EC: 1.11.1.6) as well as the ability to resist oxidative stress by the FRAP (Ferric Reducing Ability of Plasma) assay. Total erythrocyte protein levels were also examined. For the two groups of patients, several differences between the biochemical parameters tested were found. Median parasitaemia in women with malaria was 25,392 parasites/μl of blood (Range1200–82000), while in controls we had no parasites found in thin and thick smears. Levels of lipid peroxidation products (MDA) were significantly higher in patients with parasitemia than in healthy asymptomatic volunteers (mean: 0.844 ± 0.290 and 0.384 ± 0.129 respectively, p<0.001). This MDA level was higher in primigravidea and also correlates well with parasite density (p<0.001). Catalase activity in erythrocytes of women with malaria did not differ statistically from that of controls. In contrast, SOD activity of patients with malaria was found to be significantly higher than that of controls (mean: 0.7899 ± 0.2777 and 0.4263 ± 0.2629 respectively, p<0.05). FRAP values declined, from parasitemic patients (1.4619 ± 0.6565) compare to controls (2.4396 ± 0.8883, p<0.05), particularly in the first and third trimester of gestation (p<0.05 and p<0.01 respectively). Finally, total erythrocyte protein concentrations of women with malaria did not differ from that of the controls. Our results suggest an imbalance between oxidants and antioxidants in pregnant women suffering from malaria, a situation which could lead to severe damage for either the mother or the fetus. Therefore, further research should be done to assess the potential benefits of antioxidant supplementation for the pregnant women suffering from malaria.     

Some oxidative stress related parameters in patients with head and neck carcinoma

Forty cases of head and neck cancer were studied for plasma superoxide dismutase, malondialdehyde and thiol levels and results were compared with a group of forty normal healthy volunteers. Mean plasma superoxide dismutase activity was not found to be altered while malondialdehyde concentration was significantly higher when compared with the control group. On the other hand, mean thiol level was significantly lowered. The data suggests increased level of oxidative stress in patients with head and neck cancer.     

A comparative study on oxidative stress and antioxidant status in ischemic stroke patients with and without diabetes

The study was conducted to find out the extent of lipid peroxidation and antioxidant status in ischemic stroke patients (ISPs) with and without diabetes. Malondialdehyde (MDA) was studied as a marker of lipid peroxidation. Glutathione (GSH), uric acid and ceruloplasmin were estimated to study the antioxidant potential of ISPs. Significantly higher levels of MDA were found in both the groups of ISPs and the increase in MDA was more in ISPs without diabetes. GSH levels were decreased significantly in both the groups of ISPs and maximum decline was found in ISPs with diabetes. Uric acid levels were significantly increased in both the groups of ISPs. Ceruloplasmin levels were increased significantly in ISPs without diabetes, whereas its levels were slightly decreased in ISPs with diabetes. A negative correlation was found between MDA and the antioxidants GSH, uric acid and ceruloplasmin in ISPs with diabetes. This study suggests that there is an association between ischemic stroke and increased oxidative stress and the antioxidant potential is impaired in both the groups of ISPs with and without diabetes.     

Seasonal variations in markers of stress and oxidative stress in rats

High ambient temperature has been reported to increase oxidative stress by increasing lipid peroxidation and decreasing antioxidant defence in transition dairy cows. It is also known to cause an increase in plasma cortisol levels in goats, European hedgehog and human volunteers. High levels of glucocorticoids have been reported to decrease blood glutathione and erythrocyte superoxide dismutase activity in rats. Although institutional animal houses in research laboratories of developed countries maintain animals in air-conditioned rooms at constant temperature, the same is not true of animal houses in the developing countries especially those belonging to smaller institutions and this could affect the results of the experiments being conducted on these animals. The present research study was done to assess the effects of seasonal variations on the status of erythrocyte oxidative damage, antioxidant defence and plasma cortisol levels in adult female Wistar rats. Rats were kept in their home cages and were left in non-air-conditioned procedure rooms in two different seasons, Hot season (March-May) and Cool season (June to September). Erythrocyte Thiobarbituric acid reactive substances and plasma cortisol levels were significantly increased in rats exposed to high ambient temperature and humidity of the hot season as compared to the rats of the cool season. Erythrocyte reduced glutathione levels, erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly decreased in the hot season group of rats. The results of our experiments showed that exposure of adult female Wistar rats to high ambient temperature and humidity of the hot season increases neuroendocrine stress, oxidative stress and decreases antioxidant defence in them.     

Maternal and fetal indicators of oxidative stress during intrauterine growth retardation (IUGR)

The present study demonstrates the possibility of increased lipid peroxidation and protein oxidation in both maternal and fetal erythrocytes as markers of oxygen radical activity during intrauterine growth retardation. The erythrocyte MDA levels were significantly elevated in mothers of IUGR babies when compared to controls (p<0.01). The endogenous protein damage due to oxidative stress was significantly higher in IUGR mothers when compared to controls (p<0.05). Similarly the proteolytic activity in erythrocyte lysates against oxidatively damaged hemoglobin was significantly increased in mothers of IUGR babies compared to controls (p<0.001). In fetuses born with IUGR, both lipid peroxidation and proteolytic activity were significantly increased when compared to normal newborns (p<0.01). The result of this study indicates that oxidative stress was induced both in IUGR babies and their mothers which is manifested as increased lipid peroxidation and protein oxidant damage.     

Urinary 8-OHdG: A marker of oxidative stress to DNA and total antioxidant status in essential hypertension with South Indian population

Establishment of non-invasive urinary biomarker for the early prediction of essential hypertension (EH) is important. We evaluated whether estimation of urinary DNA, serves as a marker to predict the extent of cellular oxidative stress in essential hypertension. A total of 180 South Indian subjects aged 30–65 were recruited for the study. Of these hypertensive subjects investigated, 30 were newly diagnosed and were not on any antihypertensive drugs, but had systolic blood pressure 140–160 mmHg and diastolic blood pressure 95–100 mmHg and 75 hypertensive patients who already on drug therapy for one year and 75 were South Indian normotensive healthy controls with blood pressure ≤ 120/80 mmHg. The 8-OHdG level in urine was significantly increased in hypertensive patients (both newly diagnosed and who already on drug therapy) compared with control group. The significant increase in 8-OHdG was observed in newly diagnosed hypertensive patients compared with hypertensive patients who already on drug therapy. There was a significant decrease in serum TAS value in essential hypertensive group when compared to control group. The urinary 8-OHdG was independently correlated with serum TAS. Decreased TAS levels, which reflect to increased oxidative stress, may be the reason of increased urinary 8-OHdG in South Indian hypertensive patients. Our preliminary data suggest that the competitive ELISA for 8-OHdG appears to be a simple method for quantifying the extent of oxidative stress.     

Study of oxidative stress and enzymatic antioxidants in normal pregnancy

Pregnancy is a physiological state accompanied by a high-energy demand and an increased oxygen requirement. Augmented levels of oxidative stress would be expected because of the increased intake and utilization of oxygen. Evidence of increased oxidative stress in normal pregnancy in comparison with nonpregnant controls was estimated by measuring Thiobarbituric acid reactive substance (TBARS), enzymatic antioxidants like Superoxide dismutase, Glutathione peroxidase, Glutathione reductase and catalase. It was observed that pregnant women were more susceptible to oxidative damage than non-pregnants as indicated by increased TBARS and decreased antioxidants.     

Effect of short term supplementation of tomatoes on antioxidant enzymes and lipid peroxidation in type-II diabetes

The objective of the present study is to evaluate the beneficial effect of tomatoes, which are rich source of Lycopene, relatively a new carotenoid known to play an important role in human health and disease. In this study lipid peroxidation rate was measured by estimating Malondialdehyde and the levels of serum enzymes involved in antioxidant activities like Super Oxide Dismutase, Glutathione Peroxidase, Glutathione Reductase, Reduced Glutathione, in type-II diabetic group (n=40) and age matched control group (n=50), and observed significantly lower levels of antioxidant enzymes and very high lipid peroxidation rate in type-II diabetes when compared to control group (p<0.001). Short term supplementation with tomatoes (cooked) to diabetic group for a period of 30 days, showed a significant improvement in antioxidant enzyme levels (p<0.001) and decreased lipid peroxidation rate (p<0.001) suggesting the supplementation with tomato lycopene may serve as the best method of preventing the oxidative stress in diabetic patients.     

Antidiabetic and antioxidant effects of <Emphasis Type="Italic">Picrorhiza kurrooa</Emphasis> rhizome extracts in diabetic rats

Picrorhiza kurrooa is mentioned in Ayurveda for the treatment of many disorders, but it has not been subjected to systematic scientific investigations to assess its antidiabetic effect. The oral administration of aqueous and methanol extracts of P. kurrooa rhizomes (250 and 500 mg / kg body weight / day) for 15 days significantly reduced blood glucose, glycosylated haemoglobin and increased total hemoglobin, plasma insulin in alloxan-induced diabetes in albino rats. The treatment also showed significant correction in the level of nitric oxide radicals, superoxide radicals, peroxynitrite radical, lipid peroxidation, glutathione, glutathione reductase, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase and catalase in the pancreas of alloxan diabetic rats.     

Evaluation of oxidative stress, antioxidants and prolactin in infertile women

The objective of the study was to estimate the serum concentrations of oxidative stress markers-lipid hydroperoxide (MDA-Malondialdehyde), lactate dehydrogenase (LDH), nitrite; and ferric reducing antioxidant power (FRAP) — a measure of total antioxidant capacity in serum. Serum nitrite levels were high in fertile women than in infertile women (p<0.001), whereas MDA was high in infertile women than in fertile group (p<0.018). On classifying the entire group of women with infertility based on the etiology, serum MDA and LDH levels were higher in women with infertility due to unexplained factor than in women with other causes contributing to infertility compared to controls (p<0.001, p<0.02). A positive correlation among serum prolactin and nitrite suggested that hyperprolactinemia could contribute to infertility by inducing oxidative damage. Serum FRAP levels showed no significant difference in the groups studied. Lipid peroxidation was high in women with unexplained infertility which may be due to hyperprolactinemia.     

Maternal and fetal indicators of oxidative stress in various obstetric complications

The present study demonstrates the incidence of increased lipid peroxidation and protein oxidation in both maternal and fetal erythrocytes as markers of oxygen radical activity in different complications of pregnancy. In fetuses born after premature rupture of membranes, lipid peroxidation was significantly elevated as indicated by increased malondialdehyde levels (p<0.05) as compared to controls. Proteolytic activity in the erythrocytes of mothers in this group was also significantly high (p<0.01). In patients delivered by lower segment cesarian section, lipid peroxidation and proteolytic activity in maternal erythrocytes were significantly high (p<0.05 and p<0.001 respectively). In patients with prolonged second stage of labour, lipid peroxidation and proteolytic activity in maternal erythrocytes was significantly higher than in controls (p<0.001 and p<0.05 respectively). In this group, endogenous protein damage due to oxidative stress was significantly high both in the mother and the fetus (p<0.001 and p<0.05 respectively).     

Prostate specific antigen in patients of benign prostate hypertrophy and carcinoma prostate

Prostate Specific Antigen (PSA) has emerged as the most applicable and important tumor marker for carcinoma prostate. In the present study PSA was determined in serum of healthy subjects, patients of benign prostate hypertrophy (BPH) and Carcinoma Prostate (Ca−P) to evaluate its diagnostic efficiency in day to day management of prostate cancer patients and in differentiating patients of early prostate cancer from those with BPH. Receiver operating characteristic curve (ROC) revealed 2 ng/ml and 10 ng/ml cut off serum PSA level for BPH and untreated carcinoma prostate patients (Ca−P). An extremely significant increase (P<0.0001) was observed in mean PSA concentration in BPH patients and adenocarcinoma prostate patients when compared to healthy males. Clinical relevance of PSA was highlighted by a case study of cancer patient prior to any therapy till death.     

Protective influence of vitamin E on the antioxidant defence system in the whole blood and liver of normal and alloxan-induced diabetic rats

The effect of oral administration of vitamin E for twenty-eight consecutive days on blood glucose, reduced glutathione levels, antioxidant enzymes (superoxide dismutase and catalase activities), and levels of malondialdehyde (as an index of free radical-mediated lipid peroxidation) was observed in the whole blood and liver of normal and alloxan-induced diabetic rats. It was found that oral administration of vitamin E significantly (p<0.05) lowered the blood glucose level and increased the body weight of the diabetic rats. The activities of superoxide dismutase and levels of reduced glutathione increased significantly (p<0.05) while the level of lipid peroxidation decreased.