Impingement of marine organisms in a tropical atomic power plant cooling water system.

A one-year impingement monitoring was conducted at Madras Atomic Power Station (MAPS), Kalpakkam, southeastern coast of India and identified a total of 67 species of marine organisms in the cooling water system. Estimates of total annual impingement contributed about 1.47×106 individuals and 142.5t of biomass. Jellyfish contributed about 6.8×105 individuals and 135.6t of biomass. Crabs, shrimps and fish were the most vulnerable organisms contributing about 4.29×105 individuals, 1.39×105 individuals and 2.16×105 individuals respectively. Commercially important species namely Trichiurus lepturus, Sardinella longiceps and Portunus pelagicus were found to be impinged 1.88% and 0.29% by number and weight of the total biomass respectively. Out of ~327 fish species recorded at Kalpakkam, only about 9.4% of species were impinged at MAPS. Multispecies impingement at MAPS poses the problem of finding the best mitigation options for tropical conditions.

A new species of sand crab Jonas Hombron & Jacquinot, 1846 (Crustacea: Decapoda: Brachyura: Corystidae) from the southeastern coast of India.

A new species of sand crab of the genus Jonas Hombron & Jacquinot, 1846 (family Corystidae) is described from specimens collected from Kalpakkam, southeastern coast of India. Two other species, J. indicus (Chopra, 1935), and J. choprai Serène, 1971, have previously been recorded from this area. A detailed description of the new species is given and compared with the closely related J. formosae Balss, 1922, also from the Indo-West Pacific.

Imprint of monsoonal patterns on the fish assemblage in coastal waters of south-east India: a case study.

The composition, species richness and diversity of a coastal fish assemblage from the Kalpakkam coast of south-east India are described along with temporal distribution patterns related to seasonal fluctuations in dissolved oxygen, salinity, pH, chlorophyll-a, phytoplankton and zooplankton species richness and density. A total of 244 fish species belonging to 21 orders, 87 families and 163 genera were recorded. The fish assemblage was dominated by reef-associated species, followed by demersal species. The majority of the species (63%) are widely distributed in the western Indo-Pacific as well as in the central Indo-Pacific. Jaccard's coefficient analysis showed three distinct seasonal patterns of fish occurrence: pre-monsoon (PrM), monsoon (M) and post-monsoon (PoM). The maximum number of species was during the PrM period, followed by the PoM and M periods. Species occurrence analysis showed Sardinella longiceps to be dominant during PrM and M periods, Leiognathus dussumieri during the M period and Secutor insidiator and Secutor ruconius during the M and PoM periods. Canonical correspondence analysis indicated that salinity and rainfall were the two most influential environmental factors strongly correlated with temporal variation in the fish assemblage. The physico-chemical conditions, in combination with factors such as greater food availability and shelter, might control the seasonal local distribution of the ichthyofauna in these Indian coastal waters.

Hafnia alvei pyelonephritis in a renal transplant recipient: case report and review of an under-recognized nosocomial pathogen.

We describe the first case to our knowledge of Hafnia alvei pyelonephritis in a renal transplant recipient. Clinicians should consider this under-recognized pathogen when clinically evaluating immunosuppressed patients with a history of invasive procedures.

Antioxidants in food and chronic degenerative diseases.

Both preventive and chain breaking antioxidants have a role in the limitation of free radical damage. Some of these may be regarded as "classical", like vitamins E and C but others are more recently discovered, such as the flavonoids, widespread in plant tissues, and the muscle constituents anserine and carnosine. The major conditions in which the role of antioxidants is under intense investigation include coronary artery disease, cancer and diabetes. There are theoretical underpinnings for the efficacy of antioxidants in each of these, with the protection of low density lipoprotein (in respect of the first) being exceptionally persuasive. Much attention is now being focussed on the flavonoids, which are surprisingly pleiotropic in their effects. For one of them, quercetin, over a dozen seemingly independent biological effects can be listed, including the inhibition of low density lipoprotein oxidation. Flavonoids also inhibit peroxidation in foodstuffs, as opposed to tissues. There is much controversy over antioxidant supplementation policies, some authorities recommending a massive programme of supplementation for all ages and classes, others stressing the value of the traditional mixed diet. This matter is unlikely to be resolved soon, but in the meantime sensible supplementation policies should be continued for those most vulnerable, that is, babies and the aged.

Protection of plasmid pBR322 DNA by flavonoids against single-stranded breaks induced by singlet molecular oxygen.

Flavonoids, the dominant colouring pigments of plants, as well as the related polyphenol tannic acid significantly inhibit single-strand breaks in plasmid pBR322 DNA induced by singlet molecular oxygen ((1)O2). This reactive species of oxygen was generated in an aqueous buffer system by the thermal dissociation of the endoperoxide of 3,3'-(1,4-naphthylene)dipropionate. Among the antioxidants examined, myricetin showed the highest protective ability, followed by tannic acid, (+)catechin, rutin, fisetin, luteolin and apigenin, when the inhibitory abilities were compared at 90 min after incubation. The protective abilities of these compounds were both time and concentration dependent. At equimolar concentrations (100 microM) the antioxidant effect of myricetin was better than that of other known antioxidants such as lipoate, alpha-tocopherol and beta-carotene. Data, when analysed in relation to the structures of various compounds, showed a rough correlation with protective abilities. Owing to the abundance of these compounds in our normal diet, they may play significant roles in preventing oxidative damage resulting from potentially deleterious (1)O2.

In vitro modulation of rat adipocyte ghost membrane fluidity by cholesterol oxysterols.

The effects of cholesterol and cholesterol-derived oxysterols (cholestanone, cholestenone, coprostanone and epicoprostanol) on adipocyte ghost membrane fluidity were studied using a fluorescence depolarization method. The fluorescence anisotropy of the treated membranes was determined using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). Cholestanone and cholesterol decreased membrane fluidity at both the concentrations tested (10 & 50 microM) while the rest of the sterols did not exert any significant effect on membrane fluidity. In the presence of epinephrine, cholestanone partitioned more towards the lipid core but cholesterol partitioning was not affected. The fusion activation energies (delta E) obtained for membranes preincubated with cholestanone (8.6 kcal/mol) and cholesterol (8.2 kcal/mol) were not significantly different from that of untreated membranes (8.3 kcal/mol). Membranes preincubated with cholestanone and cholesterol did not exhibit any change in lipid phase throughout the temperature range (10-45 degrees C) tested. The sterols were found to inhibit fisetin-induced phospholipid methylation in isolated rat adipocytes in the rank order of cholesterol > epicoprostanol > cholestanone = cholestenone = coprostanone, while basal methylation was unaffected. When adipocytes were preincubated with the sterols before the addition of fisetin, cholestanone and cholestenone showed 74% and 66% inhibition of maximal methylation respectively. These results indicated that cholesterol oxysterols interact differently with rat adipocyte membranes, with cholestanone interacting more with phospholipids located at the inner lipid bilayer (e.g. phosphatidylethanolamine) while cholesterol interacts more with phosphatidylcholine located at the outer lipid bilayer. This differential interaction may cause selective changes in membrane fluidity at different depths of the bilayer and thus may modulate the activities of membrane-bound proteins such as enzymes and receptors.

Tannic acid inhibits insulin-stimulated lipogenesis in rat adipose tissue and insulin receptor function in vitro.

Tannins occur naturally in relatively abundant amounts in fruits, herbal medicines and common beverages. Thus an understanding of how these polyphenols affect peptide hormone action is of importance. We report here that tannic acid (a hydrolysable tannin) inhibits insulin-stimulated lipogenesis in rat adipose tissue in vitro, with an IC50 estimated to be about 350 microM. However, its monomer, gallic acid, did not show a similar inhibitory effect at concentrations up to 1 mM. The inhibition by tannic acid was less evident with higher concentrations of bovine serum albumin in the incubation buffer. This was attributed to the formation of a tannin-protein complex between bovine serum albumin and tannic acid. In a binding assay, it was observed that the specific binding of insulin to its receptor was not inhibited by tannic acid in the concentration range 0-200 microM. However, insulin-stimulated autophosphorylation of the insulin receptor, and receptor-associated tyrosine kinase phosphorylation of RR-SRC peptide, were inhibited by tannic acid at concentrations as low as 25 microM. Our data do not support the current speculation that tannins affect the activity of peptide hormones by binding to them. Therefore, our finding opens up a new perspective in the understanding of the mode of action of tannins on such hormones.

Potentiation of beta-adrenoceptor agonist mediated-lipolysis by cholesterol-derived oxysterols.

Cholesterol-derived oxysterols such as cholestanol, cholestanone and coprostanone were able to potentiate epinephrine-induced lipolysis in intact rat adipocytes but not cholesterol. The relative potency of the oxysterols followed the sequence: cholestanone > or = coprostanone > cholestanol. Cholestanone was selected to study its mode of action on epinephrine-induced lipolysis. A sustained increase in the level of cAMP was observed in adipocytes incubated with both cholestanone and epinephrine compared to a transient peaking of cAMP in adipocytes incubated with epinephrine alone. Binding assays using [125I]cyanopindolol (beta-adrenergic receptor antagonist) showed that cholestanone could increase the binding affinity of [125I]-cyanopindolol to beta-adrenergic receptors on rat adipocyte ghost membranes without affecting the total number of binding sites. The results suggest that cholestanone exerts its potentiation effect by facilitating the binding of beta-adrenergic agonist to its receptor.

Effects of aqueous celery (Apium graveolens) extract on lipid parameters of rats fed a high fat diet.

The antihyperlipidemic property of aqueous celery extract was studied in rats. Two groups of Wistar rats were fed a high fat diet for eight weeks to induce hyperlipidemia. One group was supplemented with aqueous celery extract in the diet while the other group served as control. At the end of the experiment, a significant reduction was found in the serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations in the celery-treated rats. However, the concentration of hepatic TG was significantly higher in the celery-treated group than in the control group. Hepatic triacylglycerol lipase (HL) activity was found to be significantly lower in the celery-treated rats while the reverse was observed for the hepatic microsomal P450 content. Analysis of an ethereal extract of the aqueous extract of celery by thin layer chromatography (TLC) with two different solvent systems showed that the extract did not contain 3-n-butylphthalide (BuPh), a unique compound in celery that has previously been reported to have lipid-lowering action. Our study indicates that other active principle(s) could be responsible for the observed effects of aqueous celery extract on serum and hepatic lipid levels.

Comparison of the effects of cholesterol and oxysterols on phospholipid bilayer microheterogeneity: a study of fluorescence lifetime distributions.

The homogenizing effect of cholesterol and its oxidative derivatives, 7-ketocholesterol, cholesterol 5 alpha, 6 alpha-epoxide and 25-hydroxycholesterol, in liquid-crystalline 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC) bilayer vesicles was studied using the fluorescence lifetimes of 2-(3-(diphenylhexatrienyl)propanoyl)-1-hexadecanoyl-sn-glycero-3-p hosphocholine (DPH-PC). The phase and modulation data were fitted either to discrete exponential models or to models characterized by continuous distributional lifetimes. Among all the models tested, it was found that the best one to account for the experimental data was the unimodal Lorentzian distribution. Thus, the DPH-PC lifetime was adequately described by a distributional center and a full width at half-maximum, for DOPC vesicles these values being 6.23 and 0.48 ns, respectively. Increasing the concentration of cholesterol, 7-ketocholesterol, or cholesterol 5 alpha, 6 alpha-epoxide from 0 to 30 mol% resulted in an increase of the lifetime center (e.g., 7.16 ns at 30 mol% cholesterol) and a decrease of the distributional width (e.g., 0.05 ns at 30 mol% cholesterol). On the other hand, up to 30 mol% of 25-hydroxycholesterol incorporated into the bilayer vesicles showed little influence on both lifetime parameters. Our results support the use of lifetime distributional width to evaluate membrane heterogeneity and suggest that oxysterols, depending on their molecular structural particulars, may exert cholesterol-like homogenizing effect in membranes.

Cytotoxic effect of butein on human colon adenocarcinoma cell proliferation.

Several classes of plant polyphenols namely, flavonoids, chalcones and coumarins exhibited varying degrees of inhibition on the cell proliferation of human colon adenocarcinoma cell line 220.1. At the highest concentration tested (100 microM), many of the chalcones showed > 100% growth inhibition and their order of potency was butein > 2'-hydroxychalcone > 2-hydroxychalcone > 2',6'-dihydroxy-4'-methoxychalcone > 2',4-dihydroxychalcone with IC50 values of 1.75, 6.2, 7.5, 17, 23 microM, respectively. Butein (the most potent chalcone) at 2 microM concentration inhibited the incorporation of 14C-labelled thymidine, uridine and leucine into the colon cancer cells whilst 5-fluorouracil (5-FU, a chemotherapeutic drug) at 50 microM concentration could significantly inhibit only the uridine incorporation. The mode of cytotoxic action of butein was different from 5-FU but may be similar to colchicine, a known HeLa cell inhibitor.

Inhibitory effects of plant polyphenols on rat liver glutathione S-transferases.

Several novel naturally occurring flavonoids and other polyphenols exerted varying degrees of concentration-dependent inhibition on uncharacterized rat liver glutathione S-transferase (EC 2.5.1.18, GST) isoforms. The order of inhibitory potencies of the five most potent polyphenols was tannic acid > 2-hydroxyl chalcone > butein > morin > quercetin, and their IC50 values were 1.044, 6.758, 9.033, 13.710 and 18.732 microM, respectively. Their inhibitions were reversible, as indicated by dialysis experiments. The optimum pH for the inhibitions by four of the compounds (tannic acid, butein, 2-hydroxyl chalcone and morin) was in the range of pH 6.0 to 6.5, but for quercetin the optimum pH was 8.0. These potent inhibitors possess one or more of the following chemical structural features: (a) polyhydroxylation substitutions, (b) absence of a sugar moiety, (c) for the chalcones, the presence of an open C-ring and hydroxylation at either the C-2 or C-3 position, (d) for the flavonoids, the attachment of the B-ring to C-2, and (e) a double bond between C-2 and C-3. Butein exhibited a non-competitive inhibition toward both glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB). Interestingly, tannic acid showed a non-competitive inhibition toward CDNB but a competitive inhibition toward GSH. The inhibitory potency of tannic acid on rat liver GSTs was concentration and substrate dependent. Using CDNB, p-nitrobenzyl chloride, 4-nitropyridine-N-oxide, and ethacrynic acid as substrates, the IC50 values for tannic acid were 1.044, 11.151, 20.206, and 57.664 microM, respectively.

Antiproliferative effect of polyunsaturated fatty acids and interleukin-2 on normal and abnormal human lymphocytes.

The polyunsaturated fatty acids (PUFAs), linoleic acid (LA), alpha linolenic acid (ALA), gamma linolenic acid (GLA), arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), showed inhibition of growth of both normal and abnormal (Molt-4) human lymphocytes, and inhibition was concentration-dependent. Interestingly, the production of the lymphokine Interleukin-2 (IL-2) was elevated in Molt-4 cells, but it was reduced in the normal human lymphocytes. Addition of GLA or IL-2 or a combination of both showed enhancement of SO2.- and of lipid peroxidation levels, which were significantly higher in Molt-4 cells than in the normal lymphocytes. Reduction of protein concentration was also observed in both types of cells during this treatment. The data showed that the antiproliferative effects of GLA and IL-2 may partly be exerted through the elevated production of superoxide free radicals and peroxidation products. This is a novel finding and therefore, further exploitation of combinations of PUFAs and IL-2 may be a possible way of combating cancer cell growth.

Potentiation of beta-adrenoceptor agonist-mediated lipolysis by quercetin and fisetin in isolated rat adipocytes.

Quercetin and fisetin, two naturally occurring bioflavonoids mobilized lipids and enzymes in the absence or presence of epinephrine in intact rat adipocytes. Dose-(0-250 microM) and time-(0-2 hr) course studies, showed that they stimulated phosphodiesterase (PDE) activity and simultaneously exert cyclic AMP accumulation. These bioflavonoids when present either singly or together with epinephrine stimulated the membrane-bound PDE but not the cytosolic PDE. The stimulation may act as a feedback mechanism to terminate the cyclic AMP effects. The action of theophylline, a known lipolytic agent (exerting its effects through antagonism of adenosine A1 receptor as well as PDE inhibition) was not potentiated by either fisetin or quercetin. However, the flavonoids potentiated epinephrine or isoproterenol- (a specific beta-adrenoreceptor agonist) induced lipolysis. Their effects were inhibited by propranolol (a beta-receptor antagonist). These results suggest that the flavonoids act synergistically with epinephrine on beta-adrenergic receptor and not through phosphodiesterase inhibition to stimulate adipocyte lipolysis. Increase in membrane phospholipid methylation occurred as a consequence of the epinephrine and/or quercetin/fisetin actions, and it correlated with the cellular accumulation of cyclic AMP.

Studies on lipid oxidation in fish phospholipid liposomes.

Fish phospholipid liposomes were prepared and used as an artificial membrane system to study factors influencing lipid oxidation. The extent of lipid oxidation was indexed by measuring the amount of thiobarbituric acid reactive substances (TBARS) produced. Fe2+, Fe3+, and Cu2+ were potent prooxidants in catalysing lipid oxidation. These metal ions induced lipid oxidation in a dose dependent manner. However, Zn2+, Ni2+, and Mn2+ did not significantly (p > 0.05) affect lipid oxidation at all the concentrations (1, 10, or 100 microM) studied. Morin, luteolin (flavonoids), butein (chalcone), tannic acid, ellagic acid (polyphenols), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) (synthetic antioxidants) were potent antioxidants (producing < 50% TBARS compared to control) of Fe(2+)-catalyzed lipid oxidation. Morin, luteolin, and butein possess two hydroxyl substituents, a C4 ketone structure and a 2-3 double bond, all of which contributed to their antioxidative potential. Fe2+ caused some losses of polyunsaturated fatty acids (PUFA), whereas tannic acid protected the oxidation of several of the PUFA including C 16:1 (Palmitoleic acid), C 18:3 (Linolenic acid), C 20:4 (Arachidonic acid), C 20:5 (Eicosapentaenoic acid), and C 22:6 (Docosahexaenoic acid).

Effects of gamma-linolenic acid, flavonoids, and vitamins on cytotoxicity and lipid peroxidation.

Gamma linolenic acid (GLA), a polyunsaturated fatty acid, promoted lipid peroxidation in Raji lymphoma suspension cultures, in a dose (10 microM-100 microM) and time-dependent (4 h-48 h) manner. The increase in lipid peroxidation could be correlated to an increase in cytotoxicity. The plant flavonoids (quercetin, luteolin, butein, rutin) and the fat-soluble components (retinol, retinoic acid, alpha-tocopherol) by themselves did not affect lipid peroxidation in Raji cells. Quercetin, luteolin, retinol, and alpha-tocopherol were able to inhibit cell proliferation significantly. Although GLA only decreased the cytotoxicity of retinol-treated cells, the latter compound was able to block the prooxidative action of GLA by scavenging the free radicals induced by it. Quercetin at 50 and 100 microM exerted equipotent superoxide anion scavenging effects, but at the higher concentration it had no effect on lipid peroxidation. Although the bioactive test compounds are well known natural antioxidants, interestingly, our data showed that their potent cytotoxic actions do not involve free radicals or lipid peroxidation reactions.

Antilipolytic action of hesperetin in rat adipocytes.

Hesperetin was able to inhibit both epinephrine- and theophylline-induced lipolysis in rat adipocytes. At concentrations of 125 microM and 250 microM, it could augment the inhibitory effect of low insulin concentration (17 microU/2ml) on epinephrine-induced lipolysis. The basal cyclic AMP levels and phosphodiesterase activities in intact adipocytes were unaltered by hesperetin. The antilipolytic action of hesperetin in adenosine deaminase pretreated adipocytes was abolished. Hesperetin could only prevent lipolysis but not reverse the initial lipolytic activity stimulated through the adenosine deaminase pretreatment of the adipocytes. In pertussis or cholera toxin (PT or CT) pretreated adipocytes, the antilipolytic action of hesperetin was unaffected. From the data obtained it is possible to conclude that the antilipolytic action of hesperetin is not mediated through the inhibition of cyclic AMP level nor through CT- or PT-sensitive G proteins. However, the involvement of hesperetin in preventing the accessibility of cellular receptors to the actions of lipolytic agents may be implicated.

In vitro effects of natural plant polyphenols on the proliferation of normal and abnormal human lymphocytes and their secretions of interleukin-2.

The growth of two human lymphoid tissue derived cell lines, IM-9 and Molt-4 cells together with normal lymphocytes was studied in the presence of several plant natural products. Amongst the 11 test compounds studied, the flavonoids (fustin, taxifolin, phloretin) and the polyphenol tannic acid were potent inhibitors. At concentrations ranging from 10-50 microM they exerted varying degrees of inhibition on Molt-4 cell and normal lymphocyte cell proliferation but not on the non-malignant (IM-9) cells. The order of potency was tannic acid > phloretin > taxifolin > fustin. The IL-2 level was also enhanced in the Molt-4 but inhibited in normal lymphocytes. However, its level remained unchanged in the IM-9 cells. The amount of IL-2 secreted could be directly correlated to the percentage cell growth inhibition for only Molt-4 cells. Interestingly, our findings suggest the possibility of exploiting the natural plant polyphenols for their possible use in the treatment of lymphocyte malignancy.

Protective effects of tannic acid and related natural compounds on Crotalus adamenteus subcutaneous poisoning in mice.

The plant natural products namely tannic acid and the flavonoids luteolin, kaempferol and apigenin exerted potent inhibition on the hyaluronidase enzyme. They were able to neutralize the haemorrhage induced by Crotalus adamenteus venom in mice dose-dependently from 0.12-2.4 mg/kg subcutaneously. In addition, they were able to antagonize the lethal activity of the venom when injected subcutaneously into mice and the order of potency was: tannic acid >> luteolin = kaempferol > apigenin. Tannic acid (24 mg/kg, subcutaneously) was able to reduce significantly the venom-induced elevation of blood creatine kinase activity. It could also prolong the survival time(s) of mice, when injected immediately after the administration of venom. Experimental evidence is presented for the first time that malondialdehyde in liver and kidney is significantly elevated as a result of rattlesnake venom poisoning and that this effect can be controlled by tannic acid.