Role of oxidative stress & antioxidant defence in ulcerative colitis patients from north India.

Background & objectives: Oxidative stress contributes to severity of ulcerative colitis (UC) but the status of erythrocyte antioxidant defence remains unknown. The present study was aimed to study the role of oxidative stress and antioxidant levels in erythrocytes of UC patients from north India. Methods: A total of 81 adult UC patients and 85 age and sex matched apparently healthy controls were included in this study. Levels of lipid peroxidation (LPO), reduced glutathione (GSH), catalase and superoxide dismutase (SOD) were measured in erythrocytes. Results: Mean age of UC patients was 43.5 yr (range 18-64 yr) while in the control group this was 45.3 yr (range 20-64 yr). LPO, catalase and SOD levels in UC patients were significantly increased (P<0.05) compared to healthy controls, while GSH levels in UC patients were significantly decreased (P<0.05) compared to healthy controls Ulcerative colitis activity score (UCAI) was 157.4±27.6 in UC patients. Interpretation & conclusions: Increased levels of LPO, SOD, catalase and a decreased level of GSH represent that oxidative stress plays a significant role in pathophysiology of UC. Further, the levels of LPO, GSH, catalase and SOD remained same during different UCAI.

Pro-inflammatory and anti-inflammatory cytokine response in diarrhoea-predominant Irritable bowel syndrome patients.

Background and aim: Irritable bowel syndrome (IBS) is referred to as a functional bowel disorder which is diagnosed by a number of characteristic symptoms (Rome II criteria) in the absence of detectable structural abnormalities. Low-grade inflammation of the intestine may be one of the reasons for development of diarrhoea-predominant IBS (IBS-D). We undertook this study to estimate the serum levels of pro-inflammatory (IL-6, TNF-a) and anti-inflammatory (IL-10) cytokines in IBS-D patients. Methods: A total of 108 diarrhoea patients were screened. Out of these only 63 adult IBS-D patients were enrolled. Age and sex matched 62 apparently healthy controls with no GI symptoms were also recruited. Out of 63 IBS-D patients, 37 were males while there were 32 males among the controls. The patients with IBS-D were diagnosed according to the Rome II criteria. Levels of serum IL-6, TNF-a and IL-10 were measured in all subjects using ELISA. Results: Mean (+SD) age of IBS-D patients (42.6+19.5 years) was comparable (p=0.64) to that of controls (43.5+18.7 years). The mean (+SD) levels of IL-6 in IBS-D patients (32.2+12.01pg/ ml) was significantly higher (p<0.001) than in controls (7.48+2.55pg/ml). The levels of TNF-a in IBS-D patients (16.3+5.2 pg/ml) were also significantly higher (p<0.05) than in controls (7.94+2.19 pg/ml). There was no significant difference in the serum levels of IL-10 (p=0.23) between IBS-D patients (5.75+2.1 pg/ml) and controls (5.84+1.9 pg/ml). Conclusion: Our results indicate that mild inflammation is involved in IBS-D patients as proinflammatory cytokines were increased although no difference in anti-inflammatory cytokine was observed.

Modulation of CYP4502E1 and oxidative stress by testosterone in liver and kidney of benzene treated rats.

Bilateral castration increased lipid peroxidation and consequently reduced glutathione in both liver and kidney. Testosterone administration reduced lipid peroxidation in the liver of castrated and benzene treated rats, however, reduced glutathione status could not be restored. Benzene depleted CYP4502E1 in castrated rats, however, the enzyme was restored in liver and kidney both after testosterone treatment. The results suggest that testosterone affects the metabolism and disposition of benzene by influencing CYP4502E1. Other hormonal and cellular/molecular factors may also alter the actions of testosterone. Testosterone dependent mechanism of toxicity of benzene in the liver and kidney has been discussed.

Orocecal transit time in patients with celiac disease from North India: a case control study.

AIM: The mechanisms responsible for bowel disturbances in celiac disease are still unknown. Small bowel motor abnormalities may be involved in this pathological condition; however, there is no study addressing small bowel transit in patients of celiac disease from Northern India. METHOD: The mouth-to-cecum transit time was studied in 80 celiac patients and 80 age and sex matched apparently healthy controls. RESULTS: Orocecal transit time in celiac patients was significantly delayed being 180+/-10.6 minutes (Mean+/-SE) as compared to 105+/-12.4 minutes in apparently healthy controls. CONCLUSION: This prolonged orocecal transit time could be due to impaired small bowel function (deranged motility) in patients with celiac disease.

Study of small intestinal bacterial overgrowth in North Indian patients with irritable bowel syndrome: a case control study.

BACKGROUND: Approximately 20% of the general population has irritable bowel syndrome. Despite this high prevalence, the cause of irritable bowel syndrome is unknown. There is no data available concerning the prevalence of small intestinal bacterial overgrowth in North Indian patients with irritable bowel syndrome. AIM: This study evaluated the prevalence of small intestinal bacterial overgrowth in patients with irritable bowel syndrome compared with healthy controls. METHODS: This study included 225 consecutive patients of irritable bowel syndrome between the ages 20 and 65 years attending the gastroenterology clinics. Diagnosis of irritable bowel syndrome was made according to the Rome II criteria. Small intestinal bacterial overgrowth was estimated by using the non-invasive glucose hydrogen breath test. RESULTS: Of 225 patients of irritable bowel syndrome, 160 (71.1%) were male and 65 (28.9%) were female. Of 100 controls, 65 (65%) were male and 35 (35%) female. The prevalence of small intestinal bacterial overgrowth was 25 of 225 (11.1%) patients with irritable bowel syndrome and 1 of 100 (1%) in apparently healthy controls. This difference was statistically significant. The prevalence of small intestinal bacterial overgrowth in male and female patients was not significantly different. CONCLUSION: This study indicates that the prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome patients from North India is approximately 11.1%, which is lower than the reported prevalence.

Molecular markers of heavy metal toxicity--a new paradigm for health risk assessment.

Last decade has witnessed increased interest in studies dealing with molecular markers of health and disease expression of genes. Specific toxicant "signatures" have been detected using genome base technologies such as microarrays. Further toxins have been classified on the basis of these signatures. Knowledge on these signatures has helped in the identification of novel drug candidates. This review discusses the gene expression studies recently made on arsenic, cadmium, mercury, chromium, lead, copper, nickel, manganese, and other essential elements. Toxicogenomics standards and their organizations have also been briefly described. Although this information can not be considered as complete, recent reports from different laboratories on bacteria, fish, laboratory animals and humans have been summarized. It is expected that toxicogenomics data presented in this review will be helpful in planning and excretion of human health risk assessment programs.

Small intestinal bacterial overgrowth in North Indian patients with celiac disease.

BACKGROUND: Occasionally celiac patients continue to experience gastro-intestinal symptoms even with a gluten free diet. In these cases, small intestinal bacterial overgrowth may be one of the causes of the lack of response. Therefore, this prospective study was planned to determine the prevalence of small intestinal bacterial overgrowth in celiac patients. MATERIALS AND METHODS: We studied 87 confirmed cases of celiac disease from North India and 87 age and sex matched controls. Celiac disease was confirmed by positive IgA antitissue transglutaminase on ELISA. 80 g glucose hydrogen breath test (non-invasive test) was performed to establish small intestinal bacterial overgrowth. Rise of more than 10 ppm in hydrogen concentration over baseline value within two hours was considered suggestive of small intestinal bacterial overgrowth. RESULTS: Out of 87 patients with celiac disease, 49 were male and 38 were female.The mean (+/-SD) age for male patients was 26.3 +/- 16.3 years (range 14-59 years) and for female patients was 28.4 +/- 15.6 years (range 16-58 years). Amongst the controls, 52 (59.8%) were male and 35 (40.2%) were female. The mean (+/- SD) age for male controls was 27.6 +/- 14.5 years (range 15-57 years) and for female controls was 29.3 +/- 16.5 years (range 18-59 years). Hydrogen breath test was suggestive of bacterial overgrowth in 18 of the 87 (20.7%) celiac disease patients but not in any of the apparently healthy controls. CONCLUSION: This study indicates that a large number of celiac patients from North India suffer from bacterial overgrowth which can be accordingly treated with antibiotics.

Amelioration of arsenic toxicity by L-Ascorbic acid in laboratory rat.

A study so as to confirm the protective effects of L-ascorbic acid against inorganic arsenic (As23) toxicity was made in male Wistar rats. Multiphase observations made on iAs concentration in target organs viz. liver and kidney, liver function, histopathological changes, ultrastructural alterations, lipid peroxidation, oxidative stress and iAs-DNA interaction strongly favoured its ameliorative effects. These effects could mainly be attributed to its antioxidative property. It offers help in regeneration of GSH and alpha-tocopherol. The chelaticn of iAs by ascorbic acid has also been hypothesized. Inhibition of DNA damage by ascorbic acid in liver and kidney appears to be the most significant part of this study On the basis of these results, we conclude that administration of L-ascorbic acid to arsenic affected population may prevent the occurrence of fatal human diseases.

Protective effect of ascorbic acid against oxidative stress induced by inorganic arsenic in liver and kidney of rat.

Ascorbic acid treatment in arsenic trioxide treated rats increased arsenic excretion, inhibited lipid peroxidation, improved GSH status, regulated GSSG turnover and also restored glutathione-S-transferases activity in liver and kidney. Suitable mechanisms leading to ascorbic acid protection have been discussed. Upregulation of GSH dependent enzymes was found to be necessary for a protective effect. Protection is finally attributed to higher GSH levels observed in the liver and kidney of ascorbic acid and inorganic arsenic treated rats. It is also concluded that ascorbic acid protection is influenced by gender dependent factors. Arsenic poisoning is a global problem now. Gender differences need to be considered while applying therapeutic measures.

Circadian variation in lipid peroxidation induced by benzene in rats.

Time-dependent effect of benzene, a potent carcinogenic industrial solvent, on lipid peroxidaiton and associated mechanisms has been studied in liver and kidney of rats. Significant differences were observed in the values of urinary phenol, microsomal malondialdehyde, reduced glutathione (GSH) and cytochrome P4502E1 in rats treated with benzene in morning and evening hours. Higher were the values for urinary phenol and hepatic microsomal malondialdehyde in rats administered benzene in evening hours. Contrarily, higher were the values for GSH and cytochrome P4502E1 in rats treated with benzene in morning hours. Increased microsomal lipid peroxidation has been attributed to low GSH status, whereas increased phenol concentration could be related to low activity of cytochrome P4502E1 in the liver of rats in evening hours. It is concluded that circadian rhythmicity in hepatic drug metabolizing enzyme system and GSH contributes in toxicity of benzene. The results are important from occupational health point of view.

Garlic hepatotoxicity: safe dose of garlic.

Information on the effect of garlic on the liver and optimal dose of garlic to avoid liver damage is not known. This study was planned to determine the safe dose of garlic. Male wistar rats (110-170g) were fed fresh garlic homogenate (FSH) orally in three different doses (1.0, 2.5 and 5.0 g/kg body weight/day) daily for 28 days. Liver histology, serum transaminases, bilirubin and alkaline phosphatase were estimated at 0, 14, 21 and 28 days in control and experimental animals. 1.0, 2.5 and 5.0 g/kg body weight/day of garlic showed significant (P<0.001) deterioration in liver function tests (LFT's) after 21, 14 and 7 days respectively. A 1.0 g/kg body weight/day dose of garlic was associated with marked histological damage in liver after 21 days. Therefore, three lower doses of garlic (0.1, 0.25 and 0.5 g/kg body weight/day) were given orally to another group of similar rats to determine the safe dose of garlic. LFT's were serially measured and animals were sacrificed on the 29th day of experiment. All three lower doses showed significant deterioration in the LFT's values of animals after 28 days of feeding the freshly prepared garlic homogenate. Both doses of garlic i.e. 0.1 and 0.25 g/kg body weight/day were associated with normal histology of liver, but 0.5 g/kg body weight/day dose of garlic showed morphological changes in the liver of one animal. Therefore, the present study suggests that garlic with high dose has the potential ability to induce liver damage and low doses (0.1 or 0.25 g / kg body weight/day) are safe doses of garlic.

Biochemical toxicity of benzene.

Human exposure to benzene in work environment is a global occupational health problem. After inhalation or absorption, benzene targets organs viz. liver, kidney, lung, heart and brain etc. It is metabolized mainly in the liver by cytochrome P450 multifunctional oxygenase system. Benzene causes haematotoxicity through its phenolic metabolites that act in concert to produce DNA strand breaks, chromosomal damage, sister chromatid exchange, inhibition of topoisomerase II and damage to mitotic spindle. The carcinogenic and myelotoxic effects of benzene are associated with free radical formation either as benzene metabolites or lipid peroxidation products. Benzene oxide and phenol have been considered as proheptons. Liver microsomes play an important role in biotransformation of benzene whereas in kidney, it produces degenerative intracellular changes. Cohort studies made in different countries suggest that benzene induces multiple myeloma in petrochemical workers. Though extensive studies have been performed on its toxicity, endocrinal disruption caused by benzene remains poorly known. Transgenic cytochrome P450 IIE1 mice may help in understanding further toxic manifestations of benzene.

Dietary fiber assessment of patients with irritable bowel syndrome from Northern India.

BACKGROUND: Data on the absolute fiber intake and the source of dietary fiber intake in patients with irritable bowel syndrome (IBS) have been lacking in northern Indians. OBJECTIVE: To find out the absolute fiber intake from different sources of food items in patients with IBS and healthy subjects from northern India. METHODS: Using the 72-hour recall method, dietary intake of macronutrients and fiber was determined in 33 consecutive adult patients with IBS and 33 age- and gender-matched healthy controls. RESULTS: The patients consumed lower amounts of macronutrients (protein 60.4 g vs 79.3 g, fat 47.7 g vs 65.7 g, and carbohydrates 294.6 g vs 339.8 g) and dietary fiber (8.1 g vs 15.7 g) than the control subjects. Though the patients consumed similar amount of pulses as the controls (46.6 [25.0] vs 46 [19.6] g/day), their fiber intake from pulses was lower (0.8 [0.7] vs 1.4 [0.9] g/day). The intake of fiber from vegetables and fruits was also significantly lower in patients (2.1 and 0.5 g/day, respectively) than in control subjects (5.8 and 3.9 g/day, respectively; p< 0.001 each). CONCLUSION: Total dietary fiber intake and intake of fiber from vegetables, fruits and pulses are lower in patients with IBS from northern India than in control subjects.

Lactose maldigestion in different age groups of north Indians.

Lactase activity with age has been reported in a wide variety of population globally. However, most of these studies in human have ignored to assess age stratified lactose maldigestion. Therefore, the present study was planned to determine lactose maldigestion in different age groups of north Indians adults. Two hundred apparently healthy north Indians (age rage 10-80 years) were subjected to a 50g lactose hydrogen breath test by standard method using a Model 12 Microlyzer from Quintron, USA. The percentage of lactose maldigestion was calculated for different age groups with an interval of 10 years. The results of this study revealed that the frequency of lactose maldigestion did not differ significantly among the age groups. Thus, this study suggests that lactose maldigestion is not associated with age stratification among north Indians.

Sex differences in oxidative stress induced by benzene in rats.

Role of sex differences on oxidative stress induced by benzene has been studied in liver, kidney and lungs of rat. It was observed that benzene administration enhanced lipid peroxidation in liver, kidney and lungs of rat, nevertheless, significant variations were recorded in male and female rats. Decrease of GSH and CYTP(450)2E1 was higher in female rats than male rats except lungs. The results suggest that oxidative stress induced by benzene is higher in female rats.

Gender differences in the metabolism of benzene, toluene and trichloroethylene in rat with special reference to certain biochemical parameters.

Metabolites viz. phenol, hippuric acid and total trichloro compounds of benzene, toluene and trichloroethylene respectively were estimated in the urine samples of male and female rats after exposure for a period of 30 days. The results exhibited higher metabolism in female rats than the male rats. Their metabolism might be regulated by cytochrome P450 isozymes in a gender specific manner. However, sex differences in the activity of glutathione-S-transferases of the liver have also been found to determine their toxicity. Results have been discussed with quantitative profiles of other enzymes established in the liver of male and female rats.

Inevitable glutathione, then and now.

Glutathione a predominant tripeptide thiol compound of many prokaryotes and eukaryotes, is synthesized from its precursor amino acids eg. gamma-glutamate, cysteine and glycine. It is mainly involved in detoxication mechanisms through conjugation reactions. Other functions include thiol transfer, destruction of free radicals and metabolism of various exogenous and endogenous compounds. It becomes mandatory for a cell to manage high concentration of intracellular GSH to protect itself from chemical/dug abuse. Glutathione dependent enzymes viz: glutathione-S-transferases, glutathione peroxidase, glutathione reductase and gamma-glutamate transpeptidase facilitate protective manifestations. Liver serves as a glutathione-generating factor which supplies the kidney and intestine with other constituents of glutathione resynthesis. The principal mechanism of hepatocyte glutathione turnover appears to be cellular efflux. Kidney too plays an important role in organismic GSH homeostasis. Role of GSH in organs like lung, intestine and brain has recently been described. GSH involvement in programmed cell death has also been indicated. Immense interest makes the then "thee glutathione" as "inevitable glutathione". This article describes the role of this vital molecule in cell physiology and detoxication mechanisms in particular.

Free radical scavenging and metal chelation by Tinospora cordifolia, a possible role in radioprotection.

Aqueous extract of T. cordifolia inhibited Fenton (FeSO4) reaction and radiation mediated 2-deoxyribose degradation in a dose dependent fashion with an IC50 value of 700 microg/ml for both Fenton and radiation mediated 2-DR degradation. Similarly, it showed a moderate but dose dependent inhibition of chemically generated superoxide anion at 500 microg/ml concentration and above with an IC50 value of 2000 microg/ml. Aqueous extract inhibited the formation of Fe2+-bipiridyl complex and formation of comet tail by chelating Fe2+ ions in a dose dependent manner with an IC50 value of 150 microg/ml for Fe2+-bipirydyl formation and maximally 200 microg/ml for comet tail formation, respectively. The extract inhibited ferrous sulphate mediated lipid peroxidation in a dose-dependent manner with an IC50 value of 1300 microg/ml and maximally (70%) at 2000 microg/ml. The results reveal that the direct and indirect antioxidant actions of T. cordifolia probably act in corroboration to manifest the overall radioprotective effects.

Soybean trypsin inhibitor confers protection against rotavirus infection in infant mice.

OBJECTIVE: To study the effects of soybean trypsin inhibitor (TI) on glycine uptake, glutathione (GSH) levels and morphological changes of intestine in rotavirus (RV) infected infant mice. METHODS: A total of 144 infant mice (7/8 days old) were divided in 3 groups (i.e. control, RV and RV + inhibitor). Infant mice were orally inoculated with the EB strain of RV and Trypsin protease inhibitor (TI) and 8 animals each were sacrificed on days 0,1,3,5,7 and 10 post infection (p.i). Glycine uptake (in vitro), GSH levels and histological changes were assessed in the jejunum, ileum and colon. RESULTS: Glycine uptake and GSH levels were significantly reduced on days 3 and 5 p.i in jejunum and ileum of RV inoculated animals, compared to the controls. Glycine uptake and GSH levels were maintained as in controls in the RV + TI inoculated animals on days 3 and 5 p.i in jejunum and colon but not in ileum where lesser values were recorded. Histology showed vacuolar degeneration in ileum towards the apical portion whereas normal morphology was observed in jejunum, similar to controls. No histological changes were observed in colon in any of the groups. Electron microscopic study confirmed the viral infection. CONCLUSION: Administration of Trypsin protease inhibitor along with RV reverted the effects of RV infection on amino acid uptake and GSH levels completely in the jejunum and partially in the ileum.