Bioactivity of crude ethanol extract and fractions of Eugenia uniflora (Myrtaceae) in the hepatopancreas of Oreochromis niloticus L

This study evaluates the bioactivity of the crude ethanol extract and ethyl acetate, hexane and chloroform fractions obtained from Eugenia uniflora leaves using the hepatopancreas of Oreochromis niloticus L. as an experimental model. The ethanol extract and fractions were administered to the fish orally with their feed. Twenty-four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. Histological analyses were performed using Masson's trichrome and Haematoxylin-Eosin. Histochemical studies were performed using Feulgen, PAS (Periodic Acid Schiff) and PAS + salivary amylase and Sudan IV stain. The qualitative analysis of the material showed that the crude extract and the ethyl, chloroform and hexane fractions induced vasodilation, vascular congestion and toxicity due to the presence of eosinophilic granular cells, rodlet cells, some leukocytic infiltrate and rare focal necroses. The Nile tilapia proved to be a satisfactory model for screening plant products.

The effect of crude ethanol extract and fractions of Hyptidendron canum (Pohl ex Benth) Harley on the hepatopancreas of Oreochromis niloticus L

Hyptidendron canum (Pohl ex Benth.) Harley is a native tree of the Brazilian Savannah. The fish Oreochromis niloticus L. was used as an experimental model to determine the bioactivity of the crude ethanol extract as well as ethyl acetate, hexanic and chloroform fractions obtained from its leaves. The plant ethanol extract and fractions were administered to the fish orally with their feed. Twenty four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. Histological analyses were performed using Masson's trichrome and Haematoxylin-Eosin. Histochemical studies were performed using Feulgen, PAS (Periodic Acid Schiff) and PAS + salivary amylase and Sudan IV stain. The qualitative analysis of the material showed that both the crude ethanol extract and the fractions from H. canum induced vasoactive activity, causing vasodilation and vascular congestion, and the hexanic fraction also caused an apparent proliferation of capillaries. Hepatopancreas toxicity was evident through inflammatory processes. Pancreatic (chloroform fraction) and hepatic alterations, hemorrhagic spots and necroses were observed in fish treated with-ethanol extract and fractions. This study is the first description of the biologic action of the crude ethanol extract and the hexane, ethyl acetate and chloroform fractions in fish.

Functional morphology of the hepatopancreas of Palaemonetes argentinus (Crustacea: Decapoda): influence of environmental pollution

We analyzed the morphological and functional state of hepatopancreas in Palaemonetes argentinusfrom two environments with different pesticide concentrations. Los Padres lagoon (Argentina) is an area subjectedto contamination due to the slow exchange of water, the shallow depth and the input of contaminatedwater. Prawns living in this lagoon accumulate high amounts of organochlorine pesticides in their tissues. Hepatopancreas of prawns from Canal 5, an adjacent shallow stream where the amount of pesticides is belowtoxic levels, and from Los Padres lagoon were processed by standard histological techniques with light microscopyand transmission electronic microscopy. At Los Padres lagoon, we found important tissular alterations,such as intertubular infiltration of haemocytes and connective tissue, epithelial retraction in some tubules, anda folded basal lamina. Important necrotic desquamation, with cariolysis, cariorrexis and lack of cellular detailswere also observed. Numerous tubules presented an enlarged and irregular lumen with the epithelium atrophiedor completely absent. In general, the lesions were particularly located in the medullar region of the organ. Atthe ultrastructural level, R and F cells were the most damaged. Both cell types had nuclear retraction, chromatincondensation and cytoplasmic lysis. Some R cells also had dilated mitochondria and numerous lysosomes, and the basal cytoplasm was nearly completely lysed. The hepatopancreas of prawns from Canal 5 did not evidenceany alterations. The histopathological study of the hepatopancreas is a highly sensitive tool to evaluate thephysiological condition of prawns and water quality. Other environmental conditions were similar, so it can beassumed that pollutants were the main cause of organ deterioration.

Analizamos el estado morfológico y funcional del hepatopáncreas de Palaemonetes argentinus de dosambientes con diferentes concentraciones de plaguicidas. La laguna Los Padres (Argentina) es un área sujeta a contaminación debido al lento intercambio del agua, la escasa profundidad y el influjo de agua contaminada. Las gambas acumulan aquí grandes cantidades de plaguicidasorganoclorados en sus tejidos. Los hepatopáncreas de gambas del Canal 5 y de la laguna Los Padres fueronprocesados mediante técnicas histológicas estándar para microscopía óptica y electrónica de transmisión. Loshepatopáncreas de los individuos recolectados en Los Padres tenían alteraciones tisulares importantes, comoinfiltración intertubular de hemocitos y tejido conectivo, retracción epitelial en algunos túbulos y láminas basalesplegadas. También se observó descamación necrótica importante, con cariolisis, cariorrexis y falta de detallescelulares. Vimos muchos túbulos con un lúmen irregular y agrandado, con el epitelio atrofiado o completamenteausente. En general las lesiones se localizaron en la región medular del órgano. Ambos tipos celulares mostraronretracción del núcleo, condensación de la cromatina y ruptura del citoplasma. Algunas células R también teníanmitocondrias y numerosos lisosomas dilatados, y el citoplasma basal casi completamente desintegrado. Nohallamos alteraciones en los hepatopáncreas de gambas deCanal 5. El estudio histopatológico del hepatopáncreas es una herramienta muy apropiada para evaluar la condiciónfisiológica de las gambas y la calidad del agua. Por la semejanza de otras condiciones ambientales, suponemosque los contaminantes fueron la causa principal del deterioro de los órganos.