S. K. Aggarwal

Lipid peroxide levels and antioxidant status in alcoholic liver disease.

The present study was conducted to evaluate some of the components of antioxidant defense system and oxidative damage in 20 male patients of alcoholic liver disease (ALD). The results were compared with 20 healthy male smokers and 20 healthy male non-smokers volunteers. Patients were subjected to detailed clinical examination and laboratory investigations. Blood samples were collected for estimating reduced glutathione (GSH), total thiols (T-SH) malondialdehyde (MDA), transaminases (AST, ALT), glutathione-S-transferease (GST) and gammaglutamyl transferase (GGT). Serum aspartate amino transferase (AST)/alanine amino transferase (ALT) ratio was significantly (p<0.01) reduced in ALD patients as compared to the controls. However, the core of utility of MDA and GST was found to be significantly (p<0.01) increased in ALD patients compared to controls. There was a significant negative correlation of MDA with both GSH and TSH. Plasma GGT levels were significantly (p<0.01) increased in alcoholics and the enzyme showed a significant positive correlation with MDA. These results give enough evidence of increased oxidative stress and compromised antioxidant defense system in patients with ALD.

Vitamin D: Non-skeletal actions and effects on growth

This review examines the various biological functions of vitamin D. Although active vitamin D (calcitriol) is known to affect the skeletal growth, recently it has been shown to be essential for the soft tissue growth as well. Calcitriol has important regulatory effects on almost all the organ-systems of the body. It influences the release of hormones from the endocrine glands, modulates the immune system and is also required for the normal cardiovascular, reproductive and neural functions. In addition, it has been shown to possess antitumor activity against leukemia as well as cancers of the colon, kidney, breast and prostate. The review explores the possibilities that calcitriol and its synthetic analogues may find extensive applications in the management of osteoporosis, endocrinopathies, perinatal growth retardation, psoriasis, transplantation and neoplasia.

Evaluation of the Oxidative Stress in Chronic Alcoholics

AIM The present study was conducted to assess the activity of Gamma Glutamyl Transferase (GGT) and its association with oxidative stress in alcoholics. METHOD Sixty male alcoholics with a history of alcohol abuse for more than five years were the subjects of this study. Twenty healthy male volunteers who matched in age and the socio-economic status, served as the control subjects. RESULTS GGT, reduced glutathione (GSH, a key intra-cellular antioxidant) and malondialdehyde (MDA, a marker of the oxidative stress) were assayed in the plasma of the two groups, and the results were statistically analyzed. The activity of the plasma GGT, known as a marker of Alcoholic Liver Disease (ALD); was significantly higher in the alcoholics as compared to that in the healthy controls. CONCLUSION There was a significant positive correlation between the enzyme activity and the plasma levels of MDA and this indicated that there was an increased release of this enzyme with enhanced oxidative damage, due to the generation of oxygen free radicals in the study group. There was a significantly increased level of MDA and a decrease in the level of GSH in the alcoholics as compared to those in the controls. Significant negative correlations between GGT and GSH, and between MDA and GSH were observed. The present study demonstrates that alcoholics have a compromised antioxidant defense system.

Plasma vitamin E status in head and neck cancers

Plasma vitamin E and malondialdehyde (MDA) concentrations were estimated in a group of 25 patients (17 males and 8 females) with head and neck cancer and the results were compared with a group of normal healthy controls. Plasma vitamin E levels were found to be significantly reduced while MDA levels were increased in patients than the controls. The fall in vitamin E was nearly same in all the patients studied irrespective of the site, TNM stage, histopathology and character of lesion. The levels did not vary immediately after radiotherapy but were significantly increased 3 months after the radiotherapy. These preliminary data suggest that the cancer patients have suboptimal vitamin E status which may be a contributory factor for increased lipid peroxidation in such cases.

Hyperhomocysteinemia and cardiovascular disease: The nutritional perspectives

Several members of the vitamin B-complex family are known to participate in the normal metabolism of homocysteine (Hcy). Leaving aside the genetic determinants of hyperhomocysteinemia (HHC), the deficiencies of these vitamins can also result in HHC. The situation of sustained and long standing HHC is likely to be prevalent in population groups with low/average socio-economic status, geriatric population and alcohol abusers. If not corrected by supplementation, these population groups certainly are more vulnerable to develop atherosclerosis (AS) and subsequently, cardiovascular disease (CVD). Hyperhomocysteinemia per se and/or HHC-induced oxidative stress result(s) in chronic chemical endothelial injury/dysfunction, smooth muscle proliferation, prothrombotic state and oxidation of low density lipoproteins (LDL) leading to diverse cardiovascular complications. In the first decade of the new millennium, major research efforts would be directed towards understanding the basic mechanism of HHC-induced oxidative stress and the pathophysiology of HHC-induced CVD, culminating in the evolution of hitherto unknown therapeutic strategies such as nutriceuticals and oxidant-antidotes.

Antioxidant vitamins and chemoprevention

Free radicals play an important role in human carcinogenesis and the mechanism of their counteraction by antioxidant vitamins has been reviewed. It seems more likely that these vitamins work in concert rather than acting singly. Currently available data are compatible with the notion that these vitamins act as chemopreventives against some important cancers, e.g. carotenoids for lung cancer, ascorbic acid for salivary gland cancer, tocopherols for head and neck cancers etc. Thus, a greater consumption of fruits and vegetables should be encouraged as they are the natural sources of these chemopreventive, antioxidants along with other protective factors packaged by nature. However, much work still remains to be done to establish the role of antioxidant vitamins in carcinogenesis.

Plasma vitamin E levels in carcinoma breast

Plasma vitamin E levels were estimated in 75 patients each of carcinoma breast and benign breast diseases. Mean plasma vitamin E concentration was found to be significantly reduced in malignancy compared to the controls as well as the non malignant conditions. The decrease in plasma vitamin E in cancer patients was directly related with the TNM stage of cancer. The levels, however, did not vary significantly with respect to histopathology or after 8 days of surgery.

Blood glutathione levels in head and neck malignancies.

Blood glutathione was estimated in fifty patients of head and neck cancer in the age group of 18–76 years and the results were compared with a group of normal healthy controls. Mean blood glutathione level was found to be significantly lowered in patients than the controls. Irrespective of the site, TNM classification, histopathology, and character of lesion, fall in blood glutathione was nearly same in all the patients. The mean level was significantly increased after radiotherapy when compared with the levels before radiotherapy. The decreased levels of GSH in-patients with head and neck cancer, observed in the present study, may be due to its increased utilization by the cells. The results suggest that patients with head and neck cancer have increased oxidative stress.

Vitamin D: Actions for the new millennium.

The past two decades have witnessed new facets in vitamin D metabolism. Free vitamin D3 till now considered to be limited to animal sources, has been shown to occur in plants. Further, the extrarenal synthesis of active vitamin D3 or calcitriol has been documented in physiological as well as in certain pathological conditions. At the cellular level, calcitriol acts through a dual mechanism. The genomic pathway involves the vitamin D receptor (VDR) which is of ubiquitous distribution and linked with various diseases. Besides, a nongenomic VDR—independent pathway also exists. The biological effects of calcitriol can no longer be dismissed by merely referring to calcium/bone homeostasis. It enhances the perinatal growth and suppresses the abnormal growth, as well. The effects on the endocrine, immune, cardiovascular, reproductive and nervous systems have also been characterized. It is compelling to believe that calcitriol and/or its analogues will find extensive applications at least in the treatment of osteoporosis, perinatal growth retardation, neoplasia, psoriasis, insulin resistance and transplantation.