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Toxicity of a new benthic Prorocentrum (dinophyceae) in a ciguatera endemic zone
PosterSession 3A. Foodand Natural Products
IOP3A24! TOXICITY OF A NEW BENTHICPROROCENTRUM (DINOPHYCEAE) IN A CIGUATERA ENDEMIC ZONE
L. Tenhage *1, J.F. Briand", J. Turquer", J.P. Quod 2 , S. Puiseux-Dao1 , N. Bouaicha 1 . 1 Laboratoirede Cryptogamie, CEMATMA, M.N.H.N. 12 rue Buffon, F-75005 Paris;2A.R.V.A.M.,
157
IOP3A26!
EFFECTSOF ORALLY-DOSED VIABLE PROBIOTICS ON MOUSELYMPHOCYTE PROLIFERATION P.F.A. Wright *1, P.V.Kirjavainenl-", IT. Ahokas 1, S.J. Salminen 1,2 . 1 Toxicology Key Centre, RMIT University, Melbourne, VIC, Australia; 2 Dept of Biochemistry & Food
14 rue de Stade de l'Est, F-97490 Ste Clotilde, France
Chemistry, University ofTurku, Turku, Finland
Dinoflagellates of the genus Prorocentrum ERHENBERG are common in the coral reef ecosystem. Several species of this genus are known to produce diarrhetic phycotoxins (okadaic acid, dinophysistoxins ...) and are suspected to be involved in the ciguatera fish poisoning. A new toxinogenic benthic dinoflagellate species from coral reef habitat of La Reunion Island (France, SW Indian Ocean) is described from scanning electron micrographs. Species was identified based on shape, size, surface micromorphology, thecal plate ornementation, and architecture of the periflagellar area and intercalary band. The toxicity of the algal crude extract (clone PBORNOl) was studied on several experimental models: mouse, mouse blood cells and on different mammalian cell lines. Mouse bioassay and the Neutral Red Uptake (NRU) test on mammalian cell lines showed a significant toxicity of the new dinoflagellate. However okadaic acid was not detected by HPLC analysis and the fibroblast morphology alterations were different from those associated with diarrhetic phycotoxins. These results indicate that this new algal species shows a toxicity different from that actually reported for the genus Prorocentrum.
Probiotics are live microbial feed or food supplements which beneficially affect the host by improving its intestinal microbial balance. Several probiotics have also been shown to influence immune function in humans and experimental animals. However, there is scant information comparing the immunomodulatory effects of different probiotic strains and dosage schedules. We examined the effects of various probiotic strains and dosage regimes on splenic T- and B-lymphocyte proliferation. Male Swiss mice received a daily dose (p.o., 109 viable bacterialkg body weight, in sterile saline) for 7 days, of one of the following probiotic strains, prior to splenocyte isolation (n = 3-4): Lactobacillus rhamnosus GG [ATCC 53103] (LBGG), Propionibacterium freudenreichii ssp shermanii JS [DSM 7076] (PJS), L. rhamnosus LC705 [DSM 7061] (Le), L. casei Shirota [YIT 9018] (LS), L. acidophilus [ATCC 4356] (LA) and L. gasseri [ATCC 3323] (LG). PJS, LC and LS decreased unstimulated (basal) Iymphoproliferation, whilst there was a trend towards enhancement with LA. However, PJS and LBGG enhanced both T- and B-cell mitogenesis (by 57-84%), whereas LC and LG reduced B-cell mitogenesis (by 25-30%). A higher daily dose (p.o., 10 12/kg) of LBGG, PJS or LC for 7 days resulted in a different immune profile: LBGG enhanced only B-cell mitogenesis; PJS reduced basal proliferation; and LC reduced T-cell mitogenesis. The time profile of inunune effects caused by LBGG and PJS (p.o., 1012/kglday for 3, 7 or 14 days) showed that maximal B-cell mitogenesis was achieved after 7 days for LBGG, while PJS caused maximal T-cell mitogenesis after 14 days, although basal proliferation was inhibited by the 3 and 7 day treatments. These effects indicate that different probiotic strains have specific inununomodulatory effects, and additional animal and human studies are needed to further characterise the immunological effects of each probiotic strain and their respective dose-response relationships, following a variety of oral dosage regimens. Furthermore, careful evaluation is required of mitogenesis studies that report only stimulation indices (i.e. the ratio of mitogen-stimulated proliferation to unstimulated proliferation) for probiotics which inhibit basallymphoproliferation.
IOP3A2S\
ADDITIVEESTROGENIC EFFECTOF GENISTEIN AND BISPHENOl A, AND ANTI-ESTROGENIC EFFECTOF (-)-EPIGAllOCATECHIN GALLATE IN MCF-7CELLS
K.-S. Kang *, J. Kanno, T. Inoue. Division of Cellular and Molecular Toxicology, National Institute ofHealth Sciences, 1-18-1 Kamiyoga, Setagaya-Ku, Tokyo 158, Japan Genistein (GEN), found in soy products, is a phytochemical with several potent biological activities, while Bisphenol A(BPA) is widely using in food container, can coating and dental sealants etc. We focused on both estrogenic and proliferative activity of GEN and BPA. GEN and BPA enhance the proliferation of estrogen-dependent MCF-7, human breast cancer cells, at concentrations as low as 100 oM of GEN and 8 nglml of BPA achieving similar effect to that of estradiol at 1 oM. The expression of the estrogen responsive gene, pS2 was also induced by treatment with concentration of GEN as low as 10M and BPA as low as 4 nglml in MCF-7 cells. Taken together, it is concluded that GEN and BPA can act as an estrogen agonist resulting in cell proliferation and induction of the estrogen responsive pS2 gene in MCF-7 cells. We examined whether (-)-Epigallocatechin gallate (EGCG) has an anti-estrogeinic effect after treatment with GEN and BPA, alone or in mixtures, in MCF· 7 cells. Our results showed that EGCG could inhibit cell proliferation induced by 17-a-estradiol, GEN and BPA. Therefore, it is suggested that GEN and BPA might disrupt human endocrine system at the human exposure levels, and these endocrine disrupting effects of GEN and BPA could be protected by EGCG which is major flavonoid component in green tea.
!P3A27!
A SUB-CHRONIC TOXICITY STUDYIN RATSON PHYTOSTEROL-ESTERS (PE)- A NOVEL FUNCTIONALFOOD
P.A. Hepburn *, S.A. Horner", M. Smith. SEAC Toxicology Unit,
UnileverResearch, ColworthHouse, Sharnbrook, Beds. MK44 lLQ; Alderley Park, Macclesfileld, UK
1 Zeneca-CTL,
A new margarine has been developed by Unilever which contains the novel ingredient, phytosterol esters. PE interfere with the absorption of cholesterol from the gut thereby lowering serum cholesterol levels. Though phytosterols are naturally present in vegetable oils this amount would be increased in the novel margarine resulting in approximately a IO-fold increase in consumption in typical margarine consumers. Therefore, as part of an extensive programme of safety evaluation studies we have conducted a subchronic toxicity study in which groups of Wistar-derived rats (20 r:J and 20 QIgroup) were fed diets containing PE at levels of 0,0.16, 1.6,3.2 and 8.1% for 13 consecutive weeks. Throughout the study, clinical observations, body weights, food and water consumption were measured. At the end of the study the rats were subjected to a full post mortem examination, cardiac blood samples were taken for clinical pathology, selected organs were weighed and a full tissue list was taken for subsequent histopathology examination. There were no treatment related
IOP3A24! TOXICITY OF A NEW BENTHICPROROCENTRUM (DINOPHYCEAE) IN A CIGUATERA ENDEMIC ZONE
L. Tenhage *1, J.F. Briand", J. Turquer", J.P. Quod 2 , S. Puiseux-Dao1 , N. Bouaicha 1 . 1 Laboratoirede Cryptogamie, CEMATMA, M.N.H.N. 12 rue Buffon, F-75005 Paris;2A.R.V.A.M.,
157
IOP3A26!
EFFECTSOF ORALLY-DOSED VIABLE PROBIOTICS ON MOUSELYMPHOCYTE PROLIFERATION P.F.A. Wright *1, P.V.Kirjavainenl-", IT. Ahokas 1, S.J. Salminen 1,2 . 1 Toxicology Key Centre, RMIT University, Melbourne, VIC, Australia; 2 Dept of Biochemistry & Food
14 rue de Stade de l'Est, F-97490 Ste Clotilde, France
Chemistry, University ofTurku, Turku, Finland
Dinoflagellates of the genus Prorocentrum ERHENBERG are common in the coral reef ecosystem. Several species of this genus are known to produce diarrhetic phycotoxins (okadaic acid, dinophysistoxins ...) and are suspected to be involved in the ciguatera fish poisoning. A new toxinogenic benthic dinoflagellate species from coral reef habitat of La Reunion Island (France, SW Indian Ocean) is described from scanning electron micrographs. Species was identified based on shape, size, surface micromorphology, thecal plate ornementation, and architecture of the periflagellar area and intercalary band. The toxicity of the algal crude extract (clone PBORNOl) was studied on several experimental models: mouse, mouse blood cells and on different mammalian cell lines. Mouse bioassay and the Neutral Red Uptake (NRU) test on mammalian cell lines showed a significant toxicity of the new dinoflagellate. However okadaic acid was not detected by HPLC analysis and the fibroblast morphology alterations were different from those associated with diarrhetic phycotoxins. These results indicate that this new algal species shows a toxicity different from that actually reported for the genus Prorocentrum.
Probiotics are live microbial feed or food supplements which beneficially affect the host by improving its intestinal microbial balance. Several probiotics have also been shown to influence immune function in humans and experimental animals. However, there is scant information comparing the immunomodulatory effects of different probiotic strains and dosage schedules. We examined the effects of various probiotic strains and dosage regimes on splenic T- and B-lymphocyte proliferation. Male Swiss mice received a daily dose (p.o., 109 viable bacterialkg body weight, in sterile saline) for 7 days, of one of the following probiotic strains, prior to splenocyte isolation (n = 3-4): Lactobacillus rhamnosus GG [ATCC 53103] (LBGG), Propionibacterium freudenreichii ssp shermanii JS [DSM 7076] (PJS), L. rhamnosus LC705 [DSM 7061] (Le), L. casei Shirota [YIT 9018] (LS), L. acidophilus [ATCC 4356] (LA) and L. gasseri [ATCC 3323] (LG). PJS, LC and LS decreased unstimulated (basal) Iymphoproliferation, whilst there was a trend towards enhancement with LA. However, PJS and LBGG enhanced both T- and B-cell mitogenesis (by 57-84%), whereas LC and LG reduced B-cell mitogenesis (by 25-30%). A higher daily dose (p.o., 10 12/kg) of LBGG, PJS or LC for 7 days resulted in a different immune profile: LBGG enhanced only B-cell mitogenesis; PJS reduced basal proliferation; and LC reduced T-cell mitogenesis. The time profile of inunune effects caused by LBGG and PJS (p.o., 1012/kglday for 3, 7 or 14 days) showed that maximal B-cell mitogenesis was achieved after 7 days for LBGG, while PJS caused maximal T-cell mitogenesis after 14 days, although basal proliferation was inhibited by the 3 and 7 day treatments. These effects indicate that different probiotic strains have specific inununomodulatory effects, and additional animal and human studies are needed to further characterise the immunological effects of each probiotic strain and their respective dose-response relationships, following a variety of oral dosage regimens. Furthermore, careful evaluation is required of mitogenesis studies that report only stimulation indices (i.e. the ratio of mitogen-stimulated proliferation to unstimulated proliferation) for probiotics which inhibit basallymphoproliferation.
IOP3A2S\
ADDITIVEESTROGENIC EFFECTOF GENISTEIN AND BISPHENOl A, AND ANTI-ESTROGENIC EFFECTOF (-)-EPIGAllOCATECHIN GALLATE IN MCF-7CELLS
K.-S. Kang *, J. Kanno, T. Inoue. Division of Cellular and Molecular Toxicology, National Institute ofHealth Sciences, 1-18-1 Kamiyoga, Setagaya-Ku, Tokyo 158, Japan Genistein (GEN), found in soy products, is a phytochemical with several potent biological activities, while Bisphenol A(BPA) is widely using in food container, can coating and dental sealants etc. We focused on both estrogenic and proliferative activity of GEN and BPA. GEN and BPA enhance the proliferation of estrogen-dependent MCF-7, human breast cancer cells, at concentrations as low as 100 oM of GEN and 8 nglml of BPA achieving similar effect to that of estradiol at 1 oM. The expression of the estrogen responsive gene, pS2 was also induced by treatment with concentration of GEN as low as 10M and BPA as low as 4 nglml in MCF-7 cells. Taken together, it is concluded that GEN and BPA can act as an estrogen agonist resulting in cell proliferation and induction of the estrogen responsive pS2 gene in MCF-7 cells. We examined whether (-)-Epigallocatechin gallate (EGCG) has an anti-estrogeinic effect after treatment with GEN and BPA, alone or in mixtures, in MCF· 7 cells. Our results showed that EGCG could inhibit cell proliferation induced by 17-a-estradiol, GEN and BPA. Therefore, it is suggested that GEN and BPA might disrupt human endocrine system at the human exposure levels, and these endocrine disrupting effects of GEN and BPA could be protected by EGCG which is major flavonoid component in green tea.
!P3A27!
A SUB-CHRONIC TOXICITY STUDYIN RATSON PHYTOSTEROL-ESTERS (PE)- A NOVEL FUNCTIONALFOOD
P.A. Hepburn *, S.A. Horner", M. Smith. SEAC Toxicology Unit,
UnileverResearch, ColworthHouse, Sharnbrook, Beds. MK44 lLQ; Alderley Park, Macclesfileld, UK
1 Zeneca-CTL,
A new margarine has been developed by Unilever which contains the novel ingredient, phytosterol esters. PE interfere with the absorption of cholesterol from the gut thereby lowering serum cholesterol levels. Though phytosterols are naturally present in vegetable oils this amount would be increased in the novel margarine resulting in approximately a IO-fold increase in consumption in typical margarine consumers. Therefore, as part of an extensive programme of safety evaluation studies we have conducted a subchronic toxicity study in which groups of Wistar-derived rats (20 r:J and 20 QIgroup) were fed diets containing PE at levels of 0,0.16, 1.6,3.2 and 8.1% for 13 consecutive weeks. Throughout the study, clinical observations, body weights, food and water consumption were measured. At the end of the study the rats were subjected to a full post mortem examination, cardiac blood samples were taken for clinical pathology, selected organs were weighed and a full tissue list was taken for subsequent histopathology examination. There were no treatment related