Tracing the sources of water using stable isotopes: first results along the Mangalore-Udupi region, south-west coast of India

The Mangalore and Udupi region on the south-west coast of India is characterized by small west-flowing rivers (150-250 km in length) originating in the Western Ghats (up to 1940 meters above sea level (m asl)) and joining the Arabian Sea. The area experiences a humid tropical climate with frequent, high-intensity rainfall (4000 mm annual average). Nevertheless, there is a shortage of water during the peak dry season immediately before the onset of monsoon because of a rapid fall in the groundwater level. From the humid high-altitude forests to the intense agriculture in the coastal area, there is an urgent need to understand the movement of water between evapotranspiration, rainfall, river systems and the groundwater compartments in order to achieve better water resource management. Demographic pressure on the area with over half a million inhabitants and industrial activity strongly influence this fragile ecosystem. The coastal area is characterized by shallow open wells, which are particularly sensitive to pollution and eutrophication. Stable water isotopes ((18)O and deuterium) were used for the first time in this region to determine the isotopic characteristics of the different waters. There is a clear seasonal difference in the isotopic ratios and d-excess values between the summer and winter monsoon periods, with a predominance of lighter isotopes in the latter period. No significant variations in isotopic ratios were observed in relation to altitude because of the possible role of mist formation at high altitude. Greater d-excess values were observed in the west-flowing streams than in rivers flowing east on account of the moist westerly oceanic winds and water vapour recycling.

Specific identification of pathogenic Yersinia enterocolitica by monoclonal antibodies generated against recombinant attachment invasion locus (rAil) protein

Classical pathogenic strains of Yersinia enterocolitica produce a 17 kDa outer membrane protein, Ail (attachment-invasion locus), which mediates bacterial attachment to some cultures epithelial cell lines and invasion of others. In the present study, hybridomas were developed for the production of monoclonal antibodies (MAbs) against Ail protein of Y. enterocolitica. A set of five stabilized hybridoma cell lines were generated, of which, two MAbs, YEA 302 and YEA 303, exhibited specific reaction to the native Ail protein (17 kDa) present in whole cell lysate of Y. enterocolitica strains beside having reaction with rAil. The other three MAbs, YEA 5, 17 and 32, had some cross reactions with proteins other than Ail. Two out of five MAbs were IgG1, two were IgG2b and one in IgM in nature. MAbs (YEA 302 and YEA 303) did not show any cross-reaction with whole cell lysate of Brucella abortus, Vibrio cholerae, Salmonella typhimurium and Escherichia coli and other species of Enterobacteriaceae including Y. pestis in ELISA and Western blot analysis. The presence of Ail protein among the strains recovered from pork and milk samples was evaluated by these sets of MAbs and the results were compared with the duplex PCR. Collectively, the data suggest that these MAbs may have the potential for their use in the detection of pathogenic Y. enterocolitica reliably, rapidly and at a relatively low cost.

Modulatory effect of Inula racemosa Hook. f. (Asteraceae) on experimental atherosclerosis in guinea-pigs

Objectives

Inula racemosa Hook. f. is indicated for precordial chest pain in Ayurveda. In this study, the effects of a hexane (IrH) and an alcohol extract (IrA) of Inula racemosa on atherosclerosis induced by a high-fat diet in guinea-pigs were investigated.

Methods

After 30 days on a high-fat diet (guinea-pig pellet diet + 0.2% w/w cholesterol) six animals were killed and evaluated for the onset of early atherosclerotic changes in coronary artery, aorta and major organs. The remaining animals were assigned to 5 groups of six animals each and fed for the following 90 days with a pellet diet + 0.15% w/w cholesterol (positive control) along with 100 mg/kg IrA, 100 mg/kg IrH or 10 mg/kg atorvastatin calcium. The normal control group received only the pellet diet. At the end of experimental period, serum lipid levels, heart and liver antioxidant status, area of lipophilic aortic lesions and histopathology of coronary artery were estimated.

Key findings

IrA decreased total cholesterol, triglycerides, low-density lipoprotein cholesterol and the atherogenic index, and increased high-density lipoprotein cholesterol compared with the positive control. It scavenged thiobarbituric acid reactive substances and increased reduced glutathione in liver, and enhanced superoxide dismutase and glutathione peroxidase in heart. Aortic lesion area and % bodyweight increase was least in the IrA-treated group. Coronary artery changes due to the high-fat diet were reversed by the extracts. The observed effects are presumably mediated by phenolics in IrA and sesquiterpene lactones in IrH.

Conclusions

The results demonstrate the anti-atherogenic effect of I. racemosa, thus validating the cardioprotective and anti-obesity claims in traditional medicine.

Cloning, expression and characterization of attachment-invasion locus protein (Ail) of Yersinia enterocolitica and its utilization in rapid detection by immunoassays

AIMS

Rapid detection of pathogenic Yersinia enterocolitica isolates by using antisera raised against recombinant attachment-invasion locus (Ail) protein.

METHODS AND RESULTS

The complete gene (471 bp) encoding for the Ail protein was amplified by PCR and cloned in pQE 30 UA vector. The recombinant clones were selected by polymerase chain reaction (PCR). Recombinant protein was expressed using induction with 1 mmol l(-1) final concentration of isopropylthiogalactoside (IPTG). Polyclonal antibodies were raised in mice against this purified recombinant protein. An indirect plate ELISA was standardized based on rAil protein for the detection of Y. enterocolitica. Western blot analysis with the sera raised against recombinant Ail protein exhibited reaction at 17 kDa region of the native Ail protein present in pathogenic Y. enterocolitica standard strains and strains isolated from pork samples suggesting that the antigenicity of recombinant Ail protein was similar to that of native Ail protein. Nonpathogenic Y. enterocolitica and the other species of Yersinia, namely, Y. pseudotuberculosis, Y. intermedia, Y. kristenseni, Y. fredrickseni and also the Enterobacteriaceae organisms tested were not found reacting to polyclonal antisera against this recombinant Ail protein.

CONCLUSION

The antibodies raised against recombinant Ail protein could specifically identify pathogenic Y. enterocolitica strains both by indirect plate ELISA and Western blot immunoassay.

SIGNIFICANCE AND IMPACT OF THE STUDY

The method developed in this study may find application in the detection of pathogenic Y. enterocolitica not only from food and environmental samples but also from clinical samples.

Modulatory effect of Inula racemosa Hook. f. (Asteraceae) on experimental atherosclerosis in guinea-pigs

OBJECTIVES

Inula racemosa Hook. f. is indicated for precordial chest pain in Ayurveda. In this study, the effects of a hexane (IrH) and an alcohol extract (IrA) of Inula racemosa on atherosclerosis induced by a high-fat diet in guinea-pigs were investigated.

METHODS

After 30 days on a high-fat diet (guinea-pig pellet diet + 0.2% w/w cholesterol) six animals were killed and evaluated for the onset of early atherosclerotic changes in coronary artery, aorta and major organs. The remaining animals were assigned to 5 groups of six animals each and fed for the following 90 days with a pellet diet + 0.15% w/w cholesterol (positive control) along with 100 mg/kg IrA, 100 mg/kg IrH or 10 mg/kg atorvastatin calcium. The normal control group received only the pellet diet. At the end of experimental period, serum lipid levels, heart and liver antioxidant status, area of lipophilic aortic lesions and histopathology of coronary artery were estimated.

KEY FINDINGS

IrA decreased total cholesterol, triglycerides, low-density lipoprotein cholesterol and the atherogenic index, and increased high-density lipoprotein cholesterol compared with the positive control. It scavenged thiobarbituric acid reactive substances and increased reduced glutathione in liver, and enhanced superoxide dismutase and glutathione peroxidase in heart. Aortic lesion area and % bodyweight increase was least in the IrA-treated group. Coronary artery changes due to the high-fat diet were reversed by the extracts. The observed effects are presumably mediated by phenolics in IrA and sesquiterpene lactones in IrH.

CONCLUSIONS

The results demonstrate the anti-atherogenic effect of I. racemosa, thus validating the cardioprotective and anti-obesity claims in traditional medicine.

Construction of a recombinant intergenus multidomain chimeric protein for simultaneous expression of haemolysin BL of Bacillus cereus, listeriolysin O of Listeria monocytogenes and enterotoxin B of Staphylococcus aureus

Haemolysin BL (HBL) of Bacillus cereus, listeriolysin O (LLO) of Listeria monocytogenes and enterotoxin B (SEB) of Staphylococcus aureus are among the major toxin components contributing to the pathogenicity of these organisms in foodborne illnesses. In this study, an intergenus non-toxic multidomain fusion protein (r-HLE) was generated with specificity for HBL, LLO and SEB. The fusion gene (r-hle) comprising the conserved regions of hblD and the hly and entB genes was codon-optimized for expression in Escherichia coli and encoded a 50 kDa recombinant multidomain chimeric protein (r-HLE). Hyperimmune antiserum raised against r-HLE specifically reacted with the L1 (38 kDa) component of the HBL complex of B. cereus, LLO (58 kDa) of L. monocytogenes and SEB (28 kDa) of S. aureus during Western blot analysis when tested on standard strains. During testing on isolates, the antiserum again identified the appropriate toxin molecules and was highly specific to the relevant bacterial species. The antigenicity of the SEB component of the r-HLE protein was also confirmed using a commercially available TECRA kit. The described procedure of creating a single antigenic molecule carrying components of three different toxins whilst still retaining the original antigenic determinants of individual toxins will be highly advantageous in the development of rapid, reliable and cost-effective immunoassays.

Enrichment-ELISA for detection of Salmonella typhi from food and water samples

OBJECTIVE

Development of monoclonal antibody based sandwich enzyme linked immunosorbant assay (sELISA) for rapid detection of Salmonella enterica serovar typhi (S. typhi) from food and water samples and optimization of enrichment procedures for use with the developed sELISA to increase the detection sensitivity of the assay.

METHODS

Spleen cells from BALB/c mice immunized with flagellin (H=d) antigen of S. typhi were fused with Sp2/0 myeloma cells. The hybridoma cell line specific to H=d antigen was established, characterized and ascites raised against one of these clones. The hyperimmune serum to flagellin antigen was raised in New Zealand White rabbits. An sELISA was developed using polyclonal antibody as capture and monoclonal antibody as detection antibody. To design the efficient culture strategies for use with the sELISA, different pre-enrichment and enrichment broths were evaluated. The media included buffered peptone water (BPW) and brain heart infusion broth for pre-enrichment and selenite F broth and Rappaport-Vassiliadis broth as enrichment broths. The developed sELISA with preceding enrichment step in BPW (Enrichment-ELISA) was evaluated in various food samples artificially inoculated with S. typhi bacteria. Various food (30) and water (35) samples collected from field were also tested by Enrichment-ELISA and culture method.

RESULTS

Out of four specific clones to H=d antigen, one clone (# 2/56, IgG2a isotype) was used in sELISA. The sELISA had the detection limit of 10(4)-10(5) cfu of S. typhi. Of the various broths used with sELISA, BPW was found to yield maximum ELISA values. Enrichment-ELISA, when tested in artificially inoculated food samples, generally, could detect 10(2) S. typhi cfu/mL within 10 h from various food rinses (meat, vegetable) and milk samples. After overnight enrichment in BPW, as less as 2 bacteria per 10 mL of milk, meat rinse, and chicken rinse could be detected. Only one of the field samples (water) gave false positive result by Enrichment-ELISA.

CONCLUSION

In comparison to culture, the Enrichment-ELISA is a rapid, sensitive, and specific method for detection of S. typhi from food or water samples. This method may be used as rapid screening procedure for environmental monitoring during outbreak situation.

Natural and anthropogenic factors controlling the dissolved organic carbon concentrations and fluxes in a large tropical river, India

Carbon studies in tropical rivers have gained significance since it was realized that a significant chunk of anthropogenic CO(2) emitted into the atmosphere returns to the biosphere, that is eventually transported by the river and locked up in coastal sediments for a few thousand years. Carbon studies are also significant because dissolved organic carbon (DOC) is known to complex the toxic trace metals in the river and carry them in the dissolved form. For the first time, this work has made an attempt to study the variations in DOC concentrations in space and time for a period of 19 months, and estimate their fluxes in the largest peninsular Indian river, the Godavari at Rajahmundry. Anthropogenic influence on DOC concentrations possibly from the number of bathing ghats along the banks and domestic sewage discharge into the river are evident during the pre-monsoon of 2004 and 2005. The rise in DOC concentrations at the onset of monsoon could be due to the contributions from flood plains and soils from the river catchment. Spatial variations highlighted that the DOC concentrations in the river are affected more by the anthropogenic discharges in the downstream than in the upstream. The discharge weighted DOC concentrations in the Godavari river is 3-12 times lower than Ganga-Brahmaputra, Indus and major Chinese rivers. The total carbon fluxes from the Godavari into the Bay of Bengal is insignificant (0.5%) compared to the total carbon discharges by major rivers of the world into oceans.

Detection of Salmonella enterica serovar Typhi (S. Typhi) by selective amplification of invA, viaB, fliC-d and prt genes by polymerase chain reaction in mutiplex format

AIMS

Development of a PCR assay that can target multiple genes for rapid detection of Salmonella enterica serovar Typhi (S. Typhi) from water and food samples.

METHODS AND RESULTS

PCR primers for invasion, O, H and Vi antigen genes, invA, prt, fliC-d and viaB were designed and used for the rapid detection of S. Typhi by multiplex PCR. Internal amplification control, which co-amplified with prt primers, was also included in the assay. The results showed that all cultures of Salmonella were accurately identified by the assay with no nonspecific amplification in other cultures. The assay had 100% detection probability when a cell suspension of 10(4) CFU ml(-1) (500 CFU per reaction) was used. Salmonella Typhi bacteria were artificially inoculated in the water and food (milk and meat rinse) samples and detected by mPCR after overnight pre-enrichment in buffered peptone water. No Salmonella bacteria could be detected from water samples collected from the field by mPCR or standard culture method.

CONCLUSIONS

The developed mPCR assay provides specific detection of S. Typhi.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rapid methods for detection of S. Typhi from complex environmental matrices are almost nonexistent. The mPCR assay reported in this study can be useful to identify S. Typhi bacteria in field environmental samples.

Effect of bacoside A on brain antioxidant status in cigarette smoke exposed rats

Free radicals mediated oxidative stress has been implicated in the pathogenesis of smoking-related diseases and antioxidant nutrients are reported to prevent the oxidative damage induced by smoking. Therefore, the present study was conducted to evaluate the antioxidant role of bacoside A (triterpenoid saponin isolated from Bacopa monniera) against chronic cigarette smoking induced oxidative damage in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with bacoside A (10 mg/kg b.w./day, p.o.). Antioxidant status of the brain was assessed from the levels of reduced glutathione, vitamin C, vitamin E, and vitamin A and the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The levels of copper, iron, zinc and selenium in brain and serum ceruloplasmin activity were also measured. Oxidative stress was evident from the diminished levels of both enzymatic and non-enzymatic antioxidants. Alterations in the levels of trace elements with accumulation of copper and iron, and depletion of zinc and selenium were also observed. Bacoside A administration improved the antioxidant status and maintained the levels of trace elements. These results suggest that chronic cigarette smoke exposure enhances oxidative stress, thereby disturbing the tissue defense system and bacoside A protects the brain from the oxidative damage through its antioxidant potential.

Effect of bacoside A on membrane-bound ATPases in the brain of rats exposed to cigarette smoke

Membrane-bound enzymes play a vital role in neuronal function through maintenance of membrane potential and impulse propagation. We have evaluated the harmful effects of chronic cigarette smoking on membrane-bound ATPases and the protective effect of Bacoside A in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with Bacoside A (the active principle isolated from Bacopa monniera) at a dosage of 10 mg/kg b.w/day, p.o. The levels of lipid peroxides as marker for evaluating the extent of membrane damage, the activities of Na+/K+-ATPase, Ca2+-ATPase and Mg2+-ATPase, and associated cations sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) were investigated in the brain. Neuronal membrane damage was evident from the elevated levels of lipid peroxides and decreased activities of membrane-bound enzymes. Disturbances in the electrolyte balance with accumulation of Na+ and Ca2+ and depletion of K+ and Mg2+ were also observed. Administration of Bacoside A inhibited lipid peroxidation, improved the activities of ATPases, and maintained the ionic equilibrium. The results of our study indicate that Bacoside A protects the brain from cigarette smoking induced membrane damage.

Protective effect of Premna tomentosa extract (L. verbanacae) on acetaminophen-induced mitochondrial dysfunction in rats

Allurement of herbs as health beneficial foods (physiologically functional foods) and as a source material for the development of new drugs, has led to greater furtherance in the study of herbal medicines during recent years. Plant extracts are being utilized to treat a wide variety of diseases like hepatotoxicity. Premna tomentosa is one such medicinal plant used widely in Indian ayurvedic medicine for the treatment of liver disorders. This study appraised the effectiveness of P. tomentosa leaf extract in protecting the liver against mitochondrial damage induced by acetaminophen, since mitochondrial injury has been investigated as a potential initiator of hepatotoxicity. Normal Wistar strain rats were pre-treated with P. tomentosa extract (750 mg/kg, orally) for 15 days and then intoxicated with acetaminophen (640 mg/kg, orally). Mitochondria were isolated from liver of experimental animals and assessed for the levels of lipid peroxide products, GSH and mitochondrial enzymes (isocitrate dehydrogenase, alpha-keto glutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase and cytochrome-C-oxidase). The levels of Lipid peroxidation products were increased and the levels of the other assessed parameters were significantly decreased in hepatotoxicity induced animals. Whereas, the levels were brought back to normal in P. tomentosa pre-treated rats, which shows the protective effect of the extract against mitochondrial damage. Presence of anti-oxidant compound D-limonene (58%) in P. tomentosa leaves, which is known to enhance conjugation of toxic metabolites by maintaining liver GSH concentrations may explain the hepatoprotective property of the extract.

Creatine kinase isoenzyme patterns upon chronic exposure to cigarette smoke: protective effect of Bacoside A

Cigarette smoking is implicated as a major risk factor in the development of cardiovascular and cerebrovascular diseases. Creatine kinase (CK) and its isoforms (CK-MM, MB, BB) have been advocated as sensitive markers in the assessment of cardiac and cerebral damage. Therefore, in the present study, we report the isoenzyme patterns of CK in rats upon exposure to cigarette smoke and the protective effect of Bacoside A against chronic smoking induced toxicity. Adult male albino rats were exposed to cigarette smoke and simultaneously administered with Bacoside A, the active constituent from the plant Bacopa monniera, for a period of 12 weeks. The activity of CK was assayed in serum, heart and brain, and its isoenzymes in serum were separated electrophoretically. Rats exposed to cigarette smoke showed significant increase in serum CK activity with concomitant decrease in heart and brain. Also cigarette smoke exposure resulted in a marked increase in all the three isoforms in serum. Administration of Bacoside A prevented these alterations induced by cigarette smoking. Cigarette smoking is known to cause free radical mediated lipid peroxidation leading to increased membrane permeability and cellular damage in the heart and brain resulting in the release of CK into the circulation. The protective effect of Bacoside A on the structural and functional integrity of the membrane prevented the leakage of CK from the respective tissues, which could be attributed to its free radical scavenging and anti-lipid peroxidative effect.

Protective effect of Premna tomentosa (L. Verbenaceae) extract on membrane-bound phosphatases and inorganic cations transport in acetaminophen-induced hepatotoxicity rats

Hepatic injury elicits intracellular stress that leads to peroxidation of membrane lipids accompanied by alteration of structural and functional characteristics of membrane, which affect the activities of membrane-bound ATPases. The present study appraised the membrane protective effect of Premna tomentosa, a hepatoprotective drug used in Indian traditional medicine. Wistar strain rats were pre-treated with Premna tomentosa extract (750 mg/kg, orally) for 15 days, 24 h prior to administration of acetaminophen (640 mg/kg, orally). During acetaminophen intoxication, the levels of membrane-bound enzymes were significantly decreased, total ATPase (1.63-fold), Mg(2+)ATPase (1.9-fold), Ca(2+)ATPase (1.33-fold) and Na(+)K(+)ATPase (1.73-fold) which was accompanied by changes in the levels of inorganic cations N+, K+ and Ca2+. These alterations were prevented by Premna tomentosa extract pre-treatment, which shows that Premna tomentosa supplementation could exert a beneficial effect against liver injury-induced membrane damage. The potential of the plant might be credited to the presence of antioxidant compound limonene in the plant.

Assessment of the Protective Potential ofPremna tomentosa(L. Verbenaceae) Extract on Lipid Profile and Lipid-Metabolizing Enzymes in Acetaminophen-Intoxicated Rats

OBJECTIVES

The liver is often damaged by environmental toxins, poor eating habits, alcohol and over-the-counter drug use that damage and weaken the liver, leading to important public health problems such as hepatitis, cirrhosis, and alcoholic liver diseases. It is cardinal to treat liver disorders, because it affects the biochemistry of the cell directly. Damage to the liver can be prevented by including a balanced diet that includes nutrients and herbs that support a healthy liver. Premna tomentosa (PT) is one such herbal drug used widely in India for the treatment of liver disorders, and we have already reported the hepatoprotective potential and antioxidant property of methanolic extract of PT leaves. Because injury to the liver can promote a variety of reactions with consequent effect on lipids, the present study was designed to elucidate the hypolipidemic effect of PT extract in acetaminophen (AA)-induced hepatotoxicity in rats.

DESIGN AND SUBJECTS

Animals were pretreated with PT extract (750 mg/kg, orally) for 15 days and then induced with hepatotoxicity by AA (640 mg/kg, intraperitoneally).

RESULTS

PT extract pretreatment significantly inhibited induced alterations in the levels of cholesterol, triglycerides, free fatty acids, phospholipids, serum lipoproteins, and lipid-metabolizing enzymes.

CONCLUSIONS

The results indicate that PT extract improves lipid metabolism and has the potential for use in hepatic disorders.

Antinociceptive and hypnotic effects of Premna tomentosa L. (Verbenaceae) in experimental animals

Medicinal plants are believed to be an important source of new chemical substances with potential therapeutic effects. The research into plants with alleged folklore use as pain relievers should therefore be viewed as a fruitful and logical research strategy in the search of new analgesic drugs. In the present inquiry, antinociceptive effects of Premna tomentosa (PT) leaf extract (in methanol) were explored in experimental animals by acetic acid-induced writhing, tail flick and tail clip tests. Oral administration of PT extract at different doses (100, 200, 400 and 500 mg/kg) led to significant antinociceptive effects. The extract was also tested for hypnotic effects. Treatment with extracts at different doses (100, 200, 400 and 500 mg/kg) decreased the locomotor activity and potentiated the pentobarbitone-induced sleep time. The responses were dose-dependent. On the basis of the present finding, we can conclude that PT possesses antinociceptive and hypnotic activities.

Alcoholic extract of 'Bacopa monniera' reduces the in vitro effects of morphine withdrawal in guinea-pig ileum

The effect of the alcoholic extract of the whole plant of Bacopa monniera (Scrophulariaceae) on morphine withdrawal was evaluated in vitro in guinea-pig ileum. After a 4 min in vitro exposure to morphine, addition of naloxone induced a strong contraction. Addition of various concentrations of the alcoholic extract of B. monniera (100-1000 microg/ml) 15 min before exposure to morphine reduced the naloxone-induced contraction in a dose-dependent manner. The results suggest that B. monniera extract may be useful in reducing the withdrawal symptoms induced by morphine.

Protective role of Bacopa monniera on morphine-induced brain mitochondrial enzyme activity in rats

Alcoholic extract of Bacopa monniera was tested for its protective role on morphine-induced brain mitochondrial enzyme status in rats. The level of the brain mitochondrial enzymes was significantly lower in the morphine-treated group when compared with control animals. These enzymes were maintained at normal level when Bacopa extract was administered orally at a dose of 40 mg/kg, 2 h before the administration of morphine.

Antimicrobial and phytochemical studies of Swertia corymbosa

The aqueous, methanol, chloroform and hexane extracts of Swertia corymbosa were tested (in vitro) for their antimicrobial efficiency. Maximum inhibitory activity was noticed against Staphylococcus aureus and Salmonella typhi.

Phytochemical and antimicrobial studies of Begonia malabarica

Phytochemical investigation of the various extracts of the leaves of Begonia malabarica Lam. (Begoniaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, beta-sitosterol, luteolin, quercetin and beta-sitosterol-3-beta-D-glucopyranoside. The aqueous and organic solvent extracts were also tested against ten human pathogenic bacteria and four fungal strains by the agar-well diffusion method. All the extracts were devoid of antifungal activity against the tested fungi. The hexane extract did not show any activity. The aqueous extracts showed activity against the Gram-negative bacteria except Vibrio parahaemolyticus. The chloroform and methanol extracts showed activity against all the tested bacteria. The study supported the claim of the usefulness of the plant in respiratory tract infections and also suggests its use in diarrhoea and skin diseases caused by pathogenic bacteria.

Phytochemical and antimicrobial studies on Drynaria quercifolia

Friedelin, epifriedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol 3-beta-D-glucopyranoside, and naringin were isolated from the dried rhizome of Drynaria quercifolia. The methanol extract showed broad and concentration-dependent antibacterial activity.

Protective role of Bacopa monniera on morphine induced hepatotoxicity in rats

The protective effect of Bacopa monniera on morphine induced liver antioxidant levels was studied in rats. Oral administration of alcohol extracts of Bacopa monniera induced a significant hepatoprotective effect. In the morphine treated group, a significant increase of lipid peroxidation and a significant decrease in liver antioxidant enzyme levels were observed. Simultaneous administration of morphine and Bacopa extract prevented these alterations. The results of this study showed that Bacopa monniera alcohol extract exerted a hepatoprotective effect against morphine induced liver toxicity.

Experimental myocardial necrosis in rats: role of arjunolic acid on platelet aggregation, coagulation and antioxidant status

Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body wt. (pre and post treatment), when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, alpha-tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies. This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.

Antibacterial activity of luteoforol from Bridelia crenulata

The methanol extract of Bridelia crenulata stem bark (50-1.5625 mg/ml) and its isolated luteoforol (2-0.25 mg/ml) showed concentration-dependent inhibiting activity against all 10 tested bacteria.

Effect of Indigofera tinctoria Linn on liver antioxidant defense system during D-galactosamine/endotoxin-induced acute hepatitis in rodents

Effects of pre-treatment with the alcoholic extract of I. tinctoria (500 mg/kg body wt/day, p.o. for 21 days) on liver antioxidant defense system during acute hepatitis induced by D-galactosamine (D-GalN)/endotoxin (LPS extracted by phenol water method from E. coli serotype 0111.B4; 300 mg and 30 micrograms/kg body wt/day, i.p., 18 hr before the assay) were investigated on the activities of enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase and glutathione-s-transferase, and levels of total reduced glutathione in the liver of normal and experimental groups of male albino rats. Since lipid peroxidation and associated membrane damage is a key feature of D-galN/LPS-induced liver injury, the levels of lipid peroxides, was estimated and used as an index of oxidative stress. D-GalN/endotoxin-induced hepatic damage was manifested by a significant decrease in the activities of antioxidant enzymes, decreased glutathione levels and increased levels of lipid peroxides. I. tinctoria pre-treated rats showed considerable protection against D-galN/endotoxin, induced oxidative stress as evidenced by a significant increase in the activities of all the antioxidant enzymes studied and significant decrease in the levels of lipid peroxides. Results indicate that pretreatment with I. tinctoria extract in rats is very effective in reducing D-GalN/endotoxin-induced oxidative stress suggesting an antioxidant effect.

Distribution of U-Th nuclides in the riverine and coastal environments of the tropical southwest coast of India

A reconnaissance study has been made on the distribution of 238U, 234U, 232Th and 230Th in soils, water, suspended particulate matter (SPM) and bottom sediments in the Kali river basin around Kaiga, its estuarine region and the adjacent Arabian Sea to obtain the baseline data of U-Th series nuclides in view of the commissioning of nuclear power reactors at Kaiga, near Karwar, on the southwest coast of India. Drainage basin soils developed over greywackes (the dominant litho-unit upstream) are lower in 238U/Al and 232Th/Al ratios by factors of 3-5 in comparison with those developed over tonalitic gneisses (the dominant litho-unit downstream). The dominance of the former type of soils is reflected in the composition of river-bottom sediments derived from the upstream drainage basin during the monsoon. The 232Th in bottom sediments tends to increase towards the estuarine and coastal areas, presumably due to deposition of heavy minerals and onshore transport of coastal sediments into the estuary. The dissolved U in the Kali river is low (0.001-0.02 microg/l) when compared to the major Indian rivers as the Kali river flows through U-poor greywackes. Thus, the input of dissolved U to the Kali estuary is dominated by sea water. Although there is some evidence for the removal of dissolved U at low salinity during estuarine mixing, its behaviour is conservative in the lower estuary (at higher salinities). The removal rate of dissolved U from the Kali river basin is similar to that reported from other tropical river basins. The U flux from all the west-flowing rivers of Peninsular India is estimated at 26.3 x 10(6) g/yr to the Arabian Sea which is about 2% of the flux from the Himalayan rivers to the Bay of Bengal.

Anti-inflammatory activity of Aglaia roxburghiana var. beddomei extract and triterpenes roxburghiadiol A and B

The alcoholic extracts of the aerial portion and fruits of Aglaia roxburghiana (W.& A.) Miq. var. beddomei and the triterpenes roxburghiadiol A and B isolated from this plant were investigated for their anti-inflammatory activity in rats by carrageenin induced rat paw oedema and cotton pellet granuloma methods. They were also studied for their effect on mast cell degranulation induced by compound 48/80. Potent anti-inflammatory activity was observed for the extracts of the aerial portion and fruits of A. roxburghiana as well as for the triterpenes roxburghiadiol A and B. The mast cell degranulation induced by compound 48/80 was significantly reduced by A. roxburghiana extracts and the triterpenes. The triterpenes roxburghiadiol A and B may play a significant role in the observed anti-inflammatory effect of A. roxburghiana.

Antioxidative activity of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid

The (-)-(1S, 3S) isomer of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid was synthesised by Pictet-Spengler condensation of tryptophan with acetaldehyde. It was evaluated for its antioxidative activity in the linoleic acid autooxidation system by the ferric thiocynate method. Butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), and alpha-tocopherol were used as the reference standards. The compound showed moderate antioxidative activity and also synergistic effect with the reference standards. The synergistic effect was in the increasing order of BHT, alpha-tocopherol and BHA. The synergistic effect was higher at higher concentrations studied.

Ehretianone, a novel quinonoid xanthene from Ehretia buxifolia with antisnake venom activity

Ehretianone (1), a new quinonoid xanthene, together with known sterols, was isolated from a MeOH extract of the root bark of Ehretia buxifolia. The structure of ehretianone was elucidated as 7-hydroxy-9a alpha-(3-methylbut-2-enyl)-4a alpha,9 alpha-(2-methylprop-2-enyl)-4a, 9a-dihydro-1,4-dioxoxanthene on the basis of spectroscopic data and X-ray crystallographic analysis. The antisnake venom activity of ehretianone against Echis carinatus venom in mice is also reported.

Antibacterial acivity of the essential oil of lippie nodiflora

The plant Lippia nodiflora (Family-Verbenaceae) has medicinal properties and particularly used as an antidandruff agent. The essential oil of the plant was tested for its antibacterial activity against both gram positive and Gram negative bacteria. It showed good activity and compared with standard neomycin sulphate. However, it was inactive in the case of shigella flexneri.