Estimation Of Lipid Peroxidation Research Articles

Self microemulsifying formulation of Lagerstroemia speciosa against chemically induced hepatotoxicity

Self microemulsifying formulation is an approach used for enhancing the bioavailability of poorly soluble molecules due to their lipidic nature and small particle size. The objective of the present study was to evaluate the hepatoprotective activity of poorly soluble hydroxy- and polyhydroxy-organic phytomolecules rich Lagerstroemia speciosa leaves extract in modern formulation i.e. “Self microemulsifying System”.Different doses of SME (Self microemulsifying) formulation of L. speciosa leaves extract were evaluated for the hepatoprotective activity against carbon tetrachloride induced liver toxicity in rats. The parameters evaluated were (a) biochemical parameters like serum enzymes: aspartate aminotransferase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (ALP) and total bilirubin (b) liver antioxidant parameters as estimation of Lipid peroxidation (LPO), catalase (CAT), Superoxide dismutase (SOD) activity and concentration of reduced glutathione (GSH). Oral administration of SME formulation provided the significant protection in marker enzyme of treated group at 100 mg/kg, p.o. as AST (P < 0.001), ALT (P < 0.001), ALP (P < 0.001) and total bilirubin (P < 0.001) comparable to the group treated with silymarin. Treatment with SME formulation at the doses of 100 mg/kg, p.o. significantly prevented the rise in levels of LPO significantly (P < 0.001). The GSH, SOD and CAT contents had significantly (P < 0.001) increased in SME formulation treated groups whereas carbon tetrachloride intoxicated group had shown significant decrease in these parameters compared to control group. Formulation at the dose 100 mg/kg, p.o. has shown maximum protection which was almost comparable to those of the normal control and standard. The histological observations further uphold the results for hepatoprotective activity.

BENEFICIAL EFFECTS OF ETHANOLIC LEAF EXTRACT OF CORIANDRUM SATIVUM ON METANIL YELLOW INDUCED ALTERATION INACTIVITY OF CATALASE AND LEVEL OF LIPID PEROXIDATION IN HERCINE CARDIAC TISSUE IN VITRO

Objective: The primary aim of the study was to find out a suitable effective dose of metanil yellow that can cause alterations of lipid peroxidation and catalase activity in the heart in vitro and to determine the effectiveness of graded doses of Coriandrum sativum as an antioxidant in preventing lipid peroxidative damage to cardiac tissue and back up catalase activity. Methods: Metanil yellow at different doses (10, 25, 35, 50 µl in phosphate buffer) were applied on isolated hircine heart homogenate (10%) in in vitro followed by estimation of lipid peroxidation and catalase activity after completion of the incubation period. Another set of the experiment included incubation of the heart homogenates with graded dilutions of ethanolic leaf extracts of Coriandrum sativum (CsEth) at concentrations of 10, 20, 30, 40 µl in phosphate buffer medium followed by quantification of the same biochemical parameters as above. This was followed by co-administration of the selected effective dose of metanil yellow (35 µl) and ethanolic leaf extract of Coriandrum sativum (30 µl) on heart homogenate to track the variation in lipid peroxidation and catalase activity in heart homogenate in vitro.Results: Metanil yellow significantly lowered catalase activity in isolated cardiac tissue that was reflected in elevated lipid peroxidation assuming free radical induced oxidative injury to cardiac tissue (p&lt;0.01). However ethanolic leaf extract of Cordiandrum sativum buffered such changes (p&lt;0.01) significantly, presuming a protective action against oxidative cardiac damage.Conclusion: It may be concluded that ethanolic leaf extract of Coriandrum sativum is a promising cardioprotective remedy not only in mitigating free radical mediated lipid peroxidative damage to cardiac tissue but also in reinstating normal catalase activity that may be used an unique herbal based remedy for such cardiac ailments in future.

Commentary to: “Improving the thiobarbituric acid-reactive-substances assay for estimating lipid peroxidation in plant tissues containing anthocyanin and other interfering compounds” by Hodges et al., Planta (1999) 207:604–611

Commentary to: “Improving the thiobarbituric acid-reactive-substances assay for estimating lipid peroxidation in plant tissues containing anthocyanin and other interfering compounds” by Hodges et al., Planta (1999) 207:604–611

Fish oil and wheat germ oil supplementation modulates brain injury in streptozotocin-induced diabetic rats.

Uncontrolled diabetes mellitus causes neuronal damage because of increased intracellular glucose. Natural products as complementary therapy may reduce neuronal complications. This study investigated whether fish oil (FO) and wheat germ oil (WGO) supplementation protects the brain in streptozotocin (STZ)-induced diabetic rats by estimating lipid peroxidation and the inflammatory and anti-oxidant status of the brain. Diabetes was induced in male Wistar rats by a single i.p. injection of STZ (60 mg/kg). Four weeks after diabetes induction, rats were divided into an untreated group and a group supplemented with 0.4 g/kg per day FO +WGO mix, p.o., for 4 weeks. Brain oxidant status was assessed by measuring nitric oxide (NO), malondialdehyde (MDA), reduced glutathione (GSH), the GSH/oxidized glutathione (GSSG) ratio, and superoxide dismutase (SOD) and catalase (CAT) activity. Inflammatory biomarkers (tumor necrosis factor [TNF]-α levels and nuclear factor (NF)-κβ immunoreaction) were measured in brains, combined with histological studies. Cholinergic function was assessed on the basis of acetylcholine (ACh) levels and acetylcholinesterase (AChE) activity. Supplementation with FO + WGO reduced MDA and NO ( P < 0.001) in diabetic rat brains and enhanced brain antioxidant capacity, as evidenced by increased GSH, GSH/GSSG ratio ( P < 0.01), and SOD and CAT activity ( P < 0.01). In addition, FO + WGO supplementation suppressed NF-κB immunoreaction and TNF-α levels ( P < 0.001). Cholinergic function was improved by FO + WGO as a result of increased ACh levels and reduced AChE activity ( P < 0.001). Supplementation of the diet with the FO + WGO mix modulated diabetic brain injury and this mix could potentially be used for preventing diabetic neurodegenerative sequelae.

Increased iron levels and lipid peroxidation in a Mediterranean population of Spain

Many chronic diseases are adversely affected by elevated iron levels. It has been speculated that this relationship is mediated by increased oxidative stress, due to the ability of iron to generate reactive oxygen species. The aim of this study was to assess the relationship between elevated iron levels and lipid peroxidation in Caucasian adults residing in the north-eastern Mediterranean region of Spain. This cross-sectional case-control study included 300 subjects: 150 adults displaying elevated iron levels (cases) selected from a representative sample of our general population and 150 age- and sex-matched adults exhibiting normal iron levels (controls). Dietary assessment (3-day food records), iron biomarkers (serum iron, ferritin and transferrin saturation) and lipid profile were determined. Elevated iron levels were defined by high serum ferritin (SF>110 μg/L in women and>200 μg/L in men) and/or transferrin saturation (TS)>45%. Oxidized low-density lipoprotein (oxLDL) plasma levels were measured, and oxLDL/LDL-cholesterol ratio was calculated to estimate lipid peroxidation. Multiple linear regression (MLR) models were applied. Individuals with elevated serum iron levels showed increased oxLDL/LDL ratio, but not oxLDL levels, compared to control subjects (20·92 ± 4·89 U/mmol vs. 19·72 ± 3·573 U/mmol, P = 0·028). These results were further confirmed by the regression models adjusted for demographic characteristics, diet, lipid profile and inflammation. Importantly, higher serum levels of triglycerides, LDL-cholesterol and lower intake of Vitamin E increased lipid peroxidation. In our general population, we have observed that higher circulating levels of iron, measured by serum ferritin and/or TS, increased lipid peroxidation (measured by oxLDL/LDL ratio).

Study on cerebroprotective actions of Clerodendron glandulosumleaves extract against long term bilateral common carotid artery occlusion in rats.

Stroke is a major cause of death and disability worldwide. The resulting burden on the society continues to grow, with increase in the incidence of stroke. Oxidative stress has been involved in the pathogenesis of several neurological diseases including acute stroke.Focal and global cerebral ischemia represents diseases that are common in the human population.In recent years much attention is being paid towards the exploration of herbal preparation, antioxidant agents and combination therapies including COX-2 inhibitors in experimental model of stroke.Possible effect of a hydroalcoholic leaf extract of Clerodendron glandulosumColeb (C. glandulosum)on oxidant-antioxidant status in ischemia-hypoperfusion injury in the rat forebrain has been investigated.Healthy adult male Wistar albino rats were divided into five groups (n=8). Group I was served as Sham control (normal saline 1ml/kg, orally), group II was served hypoperfusion control (normal saline 1ml/kg, orally), group III, group IV were served as hydroalcoholic extract treated (200 and 400mg/kg, orally) and group V was treated with Quercetin (10mg/kg, orally) for 14days to assess preventive and curative effects of C. glandulosum. Flavonoid and phenolic compounds exhibit a broad spectrum of biological activity, including antioxidant. C. glandulosum extract (200 and 400mg/kg, p.o) was administered orally, once daily for a period of 2 weeks after the occlusion of BCCA. After 14th days rats were subjected to behavioral studies. After behavioral studies animals were sacrificed and brain was removed and homogenized. Estimation of Lipid peroxidation (LPO) Myeloperoxidase (MPO), estimation of protein levels and the activities of Superoxide dismutase (SOD), Catalase (CAT), were performed. Infarct size and histopathological changes were observed in treated groups.

Antioxidant effect of α-tocopherol and cow urine distillate against oxidative stress induced by heavy metal toxicity in broiler chicken

Forty eight, one week old broiler chicks were randomly divided into eight groups with 6 birds each to study the antioxidant effect of αtocopherol and cow urine distillate (CUD) against oxidative stress induced by heavy metal toxicity of lead acetate and mercuric chloride. Group I served as control receiving standard feed and water ad libitum, whereas, group II, III and IV received in feed lead acetate @ 500 ppm, lead acetate @500 ppm and αtocopherol @ 300 mg/kg with lead acetate @ 500 ppm and an oral supplementation of cow urine distillate @ 1 ml/bird/day respectively. Group V, VI and VII received in feed mercuric chloride @ 50 ppm, mercuric chloride @ 50 ppm with α tocopherol @ 300 mg/kg and mercuric chloride @ 50 ppm and CUD as an oral gavage @ 1 ml/bird/day respectively throughout the experiment. Group VIII served as CUD control receiving oral gavage of CUD @ 1 ml/bird/day. Oxidative stress assessment was carried out in terms of estimation of lipid peroxidation (LPO) in erythrocytes, extent of splenotoxicity and body weight alterations. Ingestion of heavy metals resulted in significant elevation in LPO level, pathological alterations in spleen and other organs with significant reduction in body weight. The extent of pathological lesions in the spleen and the level of LPO were of lesser order in the birds supplemented with α tocopherol and CUD, therefore, it is concluded that α tocopherol and cow urine distillate have a protective effect against heavy metal toxicity in broiler chicken.

PP35 - Lipid peroxidation as a consequence of diabetes: effects of different treatment

The epidemiological studies have shown that type 2 diabetes leads to oxidative stress formation. Therefore the aim of this study has been to estimate the lipid peroxidation in type 2 patients and 50 patients (33 woman and 17 man) that were treated with insulin and antidiabetic drugs and 50 healthy subjects (35 woman and 15 man) were included into the study. Plasma of diabetes patients was characterized by enhanced activity of GSH-Px and Cu,Zn-SOD and lack of changes in GSSG-R in comparison to healthy people with no changes between patients groups. However vitamin A, E, C and reduced glutathione levels were diminished in both groups of patients (treated with insulin and antidiabetic drugs) compared to healthy subjects and the largest decrease was observed after insulin administration. Changes in antioxidant defense led to oxidative stress formation that consequence was enhanced lipid peroxidation. Increased level of 4-HNE and 4-ONE and no changes in the level of 4-HHE and MDA were observed in diabetes in comparison to healthy subjects. Significantly higher level of MDA was observed in plasma of patient after treatment with antidiabetic drugs than insulin treatment. However in plasma of diabetic patients treated with insulin and antidiabetic drugs two fold increase in the level of isoprostanes (free and total isoprostanes) and neuroprostanes in comparison to control group were also observed. Above changes were accompanied by significant increase in the activity of PAF-AH and PLA2 in the plasma of 2 type diabetes patients. Moreover diabetes leads to decrease in the free LA level as well as phospholipid AA and DHA levels and the lowest decrease in LA were observed after treatment with insulin. In conclusion, diabetes is characterized by oxidative stress and estimation of lipid peroxidation may be helpful of pharmacotherapy.

Role of manganese in protection against oxidative stress under iron starvation in cyanobacterium Anabaena 7120.

The cyanobacterium Anabaena sp. PCC 7120 was grown in presence and absence of iron to decipher the role of manganese in protection against the oxidative stress under iron starvation and growth, manganese uptake kinetics, antioxidative enzymes, lipid peroxidation, electrolyte leakage, thiol content, total peroxide, proline and NADH content was investigated. Manganese supported the growth of cyanobacterium Anabaena 7120 under iron deprived conditions where maximum uptake rate of manganese was observed with lower K(m) and higher V(max) values. Antioxidative enzymes were also found to be elevated in iron-starved conditions. Estimation of lipid peroxidation and electrolyte leakage depicted the role of manganese in stabilizing the integrity of the membrane which was considered as the prime target of oxygen free radicals in oxidative stress. The levels of total peroxide, thiol, proline and NADH content, which are the representative of oxidative stress response in Anabaena 7120, were also showed increasing trends in iron starvation. Hence, the results discerned, clearly suggested the role of manganese in protection against the oxidative stress in cyanobacterium Anabaena 7120 under iron starvation either due to its antioxidative properties or involvement as cofactor in a number of antioxidative enzymes.

Effect of socio-economic status and estimation of lipid peroxidation and antioxidant in preeclamptic pregnant women: a case–control study

Objective: Increased extent of lipid peroxidation and decreased antioxidant defense has been postulated as a major contributor to the development of preeclampsia. The present study was conducted to determine the serum level of malondialdehyde (MDA) and vitamin C in these patients. Methods: This research was conducted as a case–control study to assess the extent of lipid peroxidation and antioxidant status in 150 preeclampsia patients and 174 healthy pregnant women. Lipid peroxidation was assessed by measuring serum MDA level, and antioxidant defense was evaluated for serum vitamin C by UV spectrophotometric method. Independent sample t test and Pearson’s correlation test were used for the statistical analysis with statistical software package SPSS, version 16.0 (SPSS, Inc., Chicago, IL). Results: Our study found significantly higher level of MDA (p < 0.05) and significantly lower level of vitamin C (p < 0.05) in preeclampsia patients in comparison to the control subjects. Pearson’s correlation analysis revealed that there was negative correlation between the serum level of MDA and vitamin C for both patient (r = −0.057, p = 0.669) and control groups (r = −0.128, p = 0.487). Analysis of socio-economic data revealed that preeclampsia was more prevalent among the rural pregnant than the urban pregnant women (OR 1.44, 95% CI 0.665–3.14, p = 0.352). It was also observed that primigravida pregnant were at higher risk for the development of preeclampsia than the multigravida pregnant women (OR 1.87, 95% CI 0.868–4.04, p = 0.108). Conclusions: Elevated serum MDA and depleted serum vitamin C may be associated with the development of preeclampsia.

Piper betle extracts exhibit antitumor activity by augmenting antioxidant potential.

The present study was conducted to evaluate the methanolic extract of Piper betle leaves (MPBL) and its organic fractions with regard to antitumor activity against Ehrlich ascites carcinoma (EAC) in Swiss albino mice and to confirm their antioxidant activities. At 24 h post-intraperitoneal inoculation of tumor cells into mice, extracts were administered at 25, 50 and 100 mg/kg body weight for nine consecutive days. The antitumor effects of the extracts were then assessed according to tumor volume, packed cell count, viable and non-viable tumor cell count, median survival time and increase in life span of EAC-bearing mice. Next, hematological profiles and serum biochemical parameters were calculated, and antioxidant properties were assessed by estimating lipid peroxidation, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) levels. MPBL and the ethylacetate fraction (EPBL) at a dose of 100 mg/kg induced a significant decrease in tumor volume, packed cell volume and viable cell count and increased the life span of the EAC-bearing mice (P<0.05). Hematological and serum biochemical profiles were restored to normal levels in the extract-treated mice compared with the EAC control mice. MPBL and EPBL treatment significantly decreased lipid peroxidation (P<0.05) and restored GSH, SOD and CAT levels towards normal compared with the EAC control. Taken together, the results of the present study demonstrated that Piper betle extracts exhibit significant antitumor activity, which may be attributed to the augmentation of endogenous antioxidant potential.

The ameliorative effects of sesamol against seizures, cognitive impairment and oxidative stress in the experimental model of epilepsy.

A growing interest has recently been attracted towards the identification of plant-based medications including those with protective effects against cognitive impairment. Sesamol has shown promising antioxidant and neuroprotective effects, therefore, we aimed to evaluate its therapeutic potential in epilepsy which is commonly associated with oxidative stress and cognitive impairment. Male Wistar rats received pentylenetetrazole (PTZ) (30 mg/kg, IP) once every other day until the development of kindling, i.e., the occurrence of stage 5 of seizures for three consecutive trials. After the completion of kindling procedure, behavioural tests including elevated plus maze and passive avoidance were performed in order to assess learning and memory. Oxidative stress was assessed by estimation of lipid peroxidation and reduced glutathione. The effects of pretreatment with sesamol (10, 20, and 30 mg/kg, IP) against PTZ-induced seizures, cognitive impairment and oxidative stress were investigated. 32.45 ± 1.86 days after treatment with PTZ, kindling was developed that was associated with myoclonic jerks and generalized tonic-clonic seizures. Moreover, PTZ kindling induced a remarkable cognitive impairment and oxidative stress. Sesamol (30 mg/kg) significantly delayed the development of kindling and prevented seizure-induced cognitive impairment and oxidative stress. Sesamol exerts ameliorative effects in the experimental model of epilepsy. This phytochemical may be considered as a beneficial adjuvant for antiepileptic drugs.

Estimation of serum superoxide dismutase and serum malondialdehyde in oral submucous fibrosis: a clinical and biochemical study.

To estimate the level of lipid peroxidation product (MDA) and the activities of antioxidative enzymes superoxide dismutase (SOD) and the correlation of these parameters in Oral Submucous fibrosis (OSF). Estimation of MDA and SOD levels in OSF patients and controls. Patients above 15 years of age, who were diagnosed as OSF based upon thorough history, clinical examination and histopathological examination without any underlying systemic diseases, were included in the present study. Equal number of healthy subjects without any deleterious habits and without any clinically obvious oral lesions or systemic diseases were selected as the control group. The estimation of MDA in serum was done by thiobarbituric acid reactive species method. SOD was assayed by inhibition and autoxidation of adrenaline method. The data were analyzed with Student's t-test. Comparison of MDA, SOD among the OSF group and control group showed statistically significant increased levels of malondialdehyde and decreased levels of superoxide dismutase among the OSF groups. Significant changes were not seen in MDA and SOD levels between the different grades of OSF. From the present study, estimation of lipid peroxidation like MDA was done, which showed increased levels in the OSF group compared to the control group and antioxidant enzyme levels like SOD showed decreased levels in the OSF group compared to the control group. These can be considered as a subject of interest for their possible role in many of the precancerous and cancerous conditions.

FRIOS Parameters, Key to Reduce Feto-Maternal Mortality in Pre-Eclampsia

Objective(s): To evaluate the role of free radical induced oxidative stress in predicting, prevent and prompt management of pre-eclampsia. Method(s): This prospective study was conducted on 320 pregnant women of which 240 women with pregnancy induced hypertension taken as study group and 80 normal pregnant women were taken as control. Free radical status was evaluated by estimating lipid peroxidation product malonyladehyde and antioxidants-superoxide dismutase, catalase, glutathione reductase. Statistical analysis was done by using SPSS software. Result(s): Pre-eclampsia is significantly associated with free radical induced oxidative stress. Serum level of lipid peroxidation product malondialdehyde increased in pre-eclamptic women. Serum level of antioxidants SuperOxide Dismutase, Catalase level, Glutathione Reductase were reduced. Results are statistically significant. Conclusion(s): Free radical induced oxidative stress is increasing in pre-eclampsia and plays a critical role in etiopathogenesis of pre-eclampsia.

Preclinical evaluation of Vallaris solanacea (roth) kuntze stem for its antiulcer and antioxidant activity in wistar albino rats

In the present study we evaluated the antiulcer and antioxidant activity of methanolic extract from stem of the plant Vallaris solanacea (roth) Kuntze using various experimental models in Wister albino rats. The methanolic extract was prepared for evaluation of antiulcer activity with dose [3.2 milligram (mg)/kilogram (kg) and 6.4 mg/kg] by using models–pylorus ligation (PL) and ethanol induced gastric ulcer in rats. Antioxidant activity was evaluated by estimation of lipid peroxidation and catalase activity in the ethanol induced gastric ulcer model in rats. The results obtained from present study revealed that Vallaris solanacea methanolic extract (VSME) decreases the ulcer index significantly (p < 0.001) compared to the positive control group (Ranitidine 30 mg/kg) in both models at the both dose level. VSME also showed significant ulcer inhibition at both dose levels. In PL model of ulcer VSME decreased the volume of gastric juice, pH, total and free acidity. VSME also shown significant (p < 0.001) antioxidant activity by reduces the lipid peroxidation (LPO) and increases the catalase (CAT) activity. Present study shows that the VSME possess dose dependent antiulcer and antioxidant activity. However, further studies are required to focus on the molecular mechanism of responsible phytochemical constituents and establish exact mode of action involved in its antiulcer and antioxidant action.

Impact of nitric oxide precursor L-arginine on oxidative stress against typhoid

Typhoid fever is a global health problem caused by Salmonella. Salmonellae are gram-negative, flagellate, nonsporulating, facultative anaerobic bacilli that ferment glucose, reduce nitrate to nitrite, and synthesize peritrichous flagella when motile. Nowadays, most of the drugs are resistant, the fact of which compels the search for formulated drugs. Nitric oxide (NO) and its congeners react with different compounds or radicals probably mediating the broad-spectrum antimicrobial activity of reactive nitrogen species (RNS) as well as reactive oxygen species (ROS) against diverse microorganisms. Exogenous administration of L-arginine results in increased NO production. The formulation of NO precursors, (i.e. of L -arginine and ciprofloxacin) is used against experimentally induced salmonellosis. Lipid hydroperoxide can be decomposed to produce alkoxy and peroxy radicals which eventually yield numerous carbonyl products such as malondialdehyde (MDA). Estimation of lipid peroxidation (LPO) was done by modified method of Utley et al (1967). Infection with S. typhimurium significantly induced lipid peroxidation on days 8 and 11 as indicated by enhancement of MDA levels compared to the control mice (20 % and 9.52 %) (Tab. 1, Fig. 2, Ref. 20).

Anti-inflammatory and antioxidant potential of alginic acid isolated from the marine algae, Sargassum wightii on adjuvant-induced arthritic rats.

The present study evaluated the anti-inflammatory and antioxidant potential of alginic acid isolated from brown algae Sargassum wightii in arthritic rats. Arthritis was induced in male Sprague-Dawley rats by intradermal injection of complete Freund's adjuvant into the right hind paw, produce inflammation of the joint tissue. Paw edema volume, enzymes linked to inflammation such as cyclooxygenase, lipoxygenase and myeloperoxidase, and the level of ceruloplasmin, C-reactive protein and rheumatoid factor were evaluated in all the experimental groups. Oxidative stress during inflammation was analyzed by estimating lipid peroxidation and the activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and non-enzymatic antioxidant, reduced glutathione. Alginic acid treatment (100mg/kg) in arthritic rats exhibited reduced paw edema volume along with reduced activities of enzymes such as cyclooxygenase, lipoxygenase and myeloperoxidase. Reduction in the level of C-reactive protein, ceruloplasmin and rheumatoid factor were also observed in arthritic rats treated with alginic acid along with reduced lipid peroxidation and enhanced activities of antioxidant enzymes, which suggest the antioxidant potential of the compound. Histopathological analysis of paw tissue showed that alginic acid treatment reduced paw edema and inflammatory infiltration in arthritic rats. Overall results suggest that alginic acid isolated from Sargassum wightii exhibits potent anti-inflammatory and antioxidant activity, and can develop this marine alga as an alternative source for therapy and can be used as a drug candidate for the development of anti-inflammatory agent.

Batch and continuous biodegradation of Amaranth in plain distilled water by P. aeruginosa BCH and toxicological scrutiny using oxidative stress studies

Bacterium Pseudomonas aeruginosa BCH was able to degrade naphthylaminesulfonic azo dye Amaranth in plain distilled water within 6 h at 50 mg l(-1) dye concentration. Studies were carried out to find the optimum physical conditions and which came out to be pH 7 and temperature 30 °C. Amaranth could also be decolorized at concentration 500 mg l(-1). Presence of Zn and Hg ions could strongly slow down the decolorization process, whereas decolorization progressed rapidly in presence of Mn. Decolorization rate was increased with increasing cell mass. Induction in intracellular and extracellular activities of tyrosinase and NADH-DCIP reductase along with intracellular laccase and veratryl alcohol oxidase indicated their co-ordinate action during dye biodegradation. Up-flow bioreactor studies with alginate immobilized cells proved the capability of strain to degrade Amaranth in continuous process at 20 ml h(-1) flow rate. Various analytical studies viz.--HPLC, HPTLC, and FTIR gave the confirmation that decolorization was due to biodegradation. From GC-MS analysis, various metabolites were detected, and possible degradation pathway was predicted. Toxicity studies carried out with Allium cepa L. through the assessment of various antioxidant enzymes viz. sulphur oxide dismutase, guaiacol peroxidase, and catalase along with estimation of lipid peroxidation and protein oxidation levels conclusively demonstrated that oxidative stress was generated by Amaranth.

Validation of 1-methyl-2-phenylindole method for estimating lipid peroxidation in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9

Background: A method using 1-methyl-2-phenylindole was developed for the estimation of lipid peroxidation in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9. The method is specific for the estimation of malonaldehyde. Materials and Methods: The larvae were exposed to 0.0025, 0.025, 0.050, and 0.100μl/ml of cyclophosphamide for 24 and 48h. The homogenate was prepared of the larvae tissue explant and the absorbance was noted at 586nm. Results: A significant dose-dependent increase in the mean absorbance values was observed for both 24 and 48h of exposure as compared to the untreated group. Conclusions: On the basis of results obtained, it is suggested that the present method is more precise, accurate, and robust for the estimation of lipid peroxidation in the third instar larvae of transgenic D. melanogaster (hsp70-lacZ)Bg9.

Differential effect of oxidative stress on intestinal apparent permeability of drugs transported by paracellular and transcellular route

Increased intestinal permeability of macromolecules is a common feature of oxidative stress-induced gastrointestinal diseases; how it affects the absorption of drugs is not investigated. Hence, it was proposed to study the influence of hydrogen peroxide-induced oxidative stress on permeability of atenolol and metoprolol using a modified everted rat intestine technique. Atenolol was chosen as a marker of paracellular drug transport and metoprolol was selected to represent transcellular drug transport. Wistar rats were used as a source of intestine, which was everted using a glass rod, mounted on permeability apparatus, having test drug (100 μg/ml in Krebs) in donor compartment. Samples were taken from receiver compartment every 5 min for 60 min, and analyzed by HPLC. For induction of oxidative stress isolated ileum was incubated in H₂O₂ (200 μM) containing Krebs for 15 min and then again permeability was estimated. Extent of oxidative stress was determined by estimating lipid peroxidation using thiobarbituric acid assay, which was found to be increased by 42 % in hydrogen peroxide treated rat intestine as compared to control group. The mean apparent permeability of atenolol and metoprolol was found to be 0.054 ± 0.024 × 10⁻⁴ and 0.84 ± 0.14 × 10⁻⁴ cm/s, respectively, in control group rat intestinal segments. After exposure to hydrogen peroxide, there was a significant increase in the mean permeability of atenolol (0.11 ± 0.01 × 10⁻⁴ cm/s), however, metoprolol permeability was unaltered (0.94 ± 0.047 × 10⁻⁴ cm/s). The marked increase in the apparent permeability of atenolol may be attributed to rupture of intestinal barrier. In conclusion, the present study reports the differential effect of oxidative stress-induced damage on drug transport across rat intestine.