The In Vitro Effects of Aqueous and Ethanolic Extracts of the Leaves of Ageratum conyzoides (Asteraceae) on Three Life Cycle Stages of the Parasitic Nematode Heligmosomoides bakeri (Nematoda: Heligmosomatidae)

A comparative in vitro study was carried out to determine the ovicidal and larvicidal activity of aqueous and ethanolic extracts of Ageratum conyzoides (Asteraceae) leaves on the eggs (unembryonated and embryonated), first and second larval stages of Heligmosomoides bakeri. Four different concentrations (0.625, 1.25, 2.5, and 3.75 mg·mL−1) of both aqueous and ethanolic extracts were tested. Distilled water and 5% tween were used as negative controls in the bioassay. In fact, they did not affect development of eggs, hatching, and larval survival. The extract activities were dose dependent. The ethanolic extract was more potent against embryonation (39.6 ± 2.9%) than the aqueous extract (53.3 ± 10.9%) at the highest concentration (3.75 mg·ml−1). Both types of extracts killed larvae. Mebendazole proved more lethal (EC50 of 0.745 and 0.323 mg·mL−1, resp., for L1 and L2 larvae). The aqueous extracts were the least lethal (EC50 of 4.76 and 2.29 mg·mL−1, resp., for L1 and L2 larvae). The ethanolic extracts showed intermediate activity (EC50 of 1.323 and 1.511 mg·mL−1, resp., for L1 and L2 larvae). It is concluded that the ovicidal and larvicidal properties of aqueous and ethanolic extracts of Ageratum conyzoides leaves are demonstrated in this work

Incidence of intersex and reproductive status in the clam Scrobicularia plana from 13 sites in NW France

The endobenthic clam Scrobicularia plana is important for the structure and functioning of estuarine and coastal mudflats, and thus the reproduction success of this species is a topic of interest for environmental conservation. In thirteen estuaries from NW France differing by their degree of contamination (as documented by the data of RNO for Réseau National d'Observation, now ROCCH, Réseau d'Observation de la Contamination Chimique du milieu marin at http:// wwz.ifremer.fr/envlit/), intersex and different parameters linked to reproduction (sex-ratio, gonadosomatic index) were examined in S. plana collected at the beginning of gametogenesis and at the peak of sexual maturity. Both temporal and intersite differences were shown. Some reports exists showing that the presence of several endocrine disrupting chemicals (EDCs) may be directly linked to the incidence of intersex in S. plana and, in other bivalve species, an induction of female-biased sex ratios were observed after exposure to EDCs at the larval stage. Thus, the presence of EDCs in superficial sediments collected in parallel to clams was investigated by using an approach combining quantitative chemical analyses of the main classes of EDCs and a battery of in vitro bioassays allowing the quantification of receptor-mediated activities, namely estrogen (ER), androgen (AR) and dioxin (AhR) receptors. In addition, the reproductive success may be impaired indirectly when species used as food are impacted in contaminated sites, limiting food availability and then energy ressources devoted to the reproduction of consumers. This hypothesis was tested concurrently with endocrine disruption by determining hepatosomatic indices and measuring chlorophyll and phaeopigments in superficial sediments, the microphytobenthos of which is a major food source for deposit-feeding bivalves such as S. plana

Evaluation of the contamination of the Loire estuary by endocrine disruptors

Estuaries are ecosystems of high productivity, crucial in the life history of fishes, invertebrates, birds, including commercially important species, but anthropogenic activities such as urban effluents are often the main factors responsible for water quality degradation. Complex mixtures of contaminants are present in these zones and in this context; there is a growing interest in the influence of endocrine disruptor compounds (EDCs) on biota physiology. The Loire estuary runs through important urban sites (Nantes, Saint-Nazaire, etc.) with shipping and industrial activities. Moreover, the Loire basin (117,000 km²) represents more than 1/5 of the French territory and drains a lot of tributaries. The aim of this research is to evaluate the contamination of the Loire estuary by EDCs. Twelve sites along the Loire estuary (from Saint-Nazaire to Ancenis) were selected because of their typology of contamination (agricultural, urban, and industrial) and of their particular configuration (upstream/downstream of an effluent site close to a wastewater treatment plant). The endocrine activities in sediment were followed using various bio-analytical tools (in vitro tests of hormonal activities on cellular cultures). The presence of PAHs and dioxine-like compounds was estimated using the EROD test. The eel Anguilla anguilla was chosen for her ecological representativeness and economical incidence on fishing activities and was collected on 3 sites along the Loire estuary (upstream, intermediate, and downstream). The in situ effects on fish were evaluated by measuring biological variables at the individual level (size, sex, gonads histology, vitellogenin and aromatase)

Evaluation of the contamination of the Loire estuary by endocrine disruptors

Estuaries are ecosystems of high productivity, crucial in the life history of fishes, invertebrates, birds, including commercially important species, but anthropogenic activities such as urban effluents are often the main factors responsible for water quality degradation. Complex mixtures of contaminants are present in these zones and in this context; there is a growing interest in the influence of endocrine disruptor compounds (EDCs) on biota physiology. The Loire estuary runs through important urban sites (Nantes, Saint-Nazaire, etc.) with shipping and industrial activities. Moreover, the Loire basin (117,000 km²) represents more than 1/5 of the French territory and drains a lot of tributaries. The aim of this research is to evaluate the contamination of the Loire estuary by EDCs. Twelve sites along the Loire estuary (from Saint-Nazaire to Ancenis) were selected because of their typology of contamination (agricultural, urban, and industrial) and of their particular configuration (upstream/downstream of an effluent site close to a wastewater treatment plant). The endocrine activities in sediment were followed using various bio-analytical tools (in vitro tests of hormonal activities on cellular cultures). The presence of PAHs and dioxine-like compounds was estimated using the EROD test. The eel Anguilla anguilla was chosen for her ecological representativeness and economical incidence on fishing activities and was collected on 3 sites along the Loire estuary (upstream, intermediate, and downstream). The in situ effects on fish were evaluated by measuring biological variables at the individual level (size, sex, gonads histology, vitellogenin and aromatase)

Incidence of intersex along a contamination gradient in 13 estuaries of NW France : relation with endocrine disruptors compounds ?

Background. Sorne reports showed that the presence of endocrine disrupting chemicals (EDCs) may be linked to the incidence of intersex in the clam Scrobicularia. plana. Objective. We aimed at assessing the prevalence of intersex in estuaries of NW France and the possible correlation with EDCs. Method. ln thirteen estuaries contaminated at different levels (data from ROCCH, Réseau d'Observation de la Contamination Chimique du milieu marin at http://wwz.ifremer.fr/envliU), intersex and parameters associated with reproduction (sex-ratio, gonadosomatic index) were examined. Clams were collected at the beginning of gametogenesis and at the peak of sexual maturity. lntersex was determined on thin cuts of gonad tissues embedded in paraffin or on gonad smears. The presence of EDCs in sediments collected in parallel with clams was assessed by using an approach combining quantitative chemical analyses of the main classes of EDCs and a battery of in vitro bioassays. Results. Histological observation at the peak of sexual maturity revealed the presence of intersex in sevensites at different levels of intensity from 7 to 57% of males impacted. ln vitro bioassays showed estrogenic activities in all the 13 sites with the highest level in the site where the highest impact of intersex was observed. Androgenic activities were observed only in 3 sites whereas anti-androgenic activities were found in 11 sites. Ali the sites showed dioxin-like activities with different intensity. The observation of thin cuts ofgonad tissues at the beginning of gametogenesis and the chemical analysis of sediments are ongoing to strenghten these findings

Patulin and secondary metabolite production by marine-derived Penicillium strains

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