Search

In the current investigation, we evaluated the biological consequences of trace elements contamination in the two Tunisian gulfs (Gabes gulf and Tunis gulf) on the blue swimming crabs hepatopancreas (Portunus segnis). The concentrations of three trace elements (cadmium, copper, and lead) in the hepatopancreas P.segnis were evaluated. Additionally, acetylcholinesterase (AChE), metallothioneins (MTs), hydroxide peroxidase (H2O2) and advanced oxidation protein products (AOPP) levels, were chosen as measurements to evaluate the environmental effects on the two crabs’ populations from different gulfs. Macromolecular (lipids, proteins, and DNA) were also determined in P.segnis hepatopancreas. The results of trace elements bioaccumulation in soft P. segnis hepatopancreas showed a high pollution in the Gabes gulf as evidence by significant accumulation of cadmium, cooper, and lead. These findings were confirmed by significant increases of metal pollution index (MPI) and metallothioneins (MTs) levels in the hepatopancreas of P. segnis from Gabes gulf than these from Tunis gulf. Consequently, the trace elements accumulation in P.segnis from Gabes gulf conduct to the generation of lipid peroxidation processes as documented by the high levels of H2O2and LOOH. A significant decrease of AChE activity was recorded in crabs collected from Gabes gulf as compared to these from Tunis gulf. The present study revealed depletion of proteins and lipids contents, while DNA showed significant degradation on crab hepatopancreas collected from Gabes gulf comparing to Tunis gulf. These evidences must be taken in consideration when using P. segnis as an ecological indicator species in the biomonitoring programs., Na investigação atual, avaliamos as consequências biológicas da contaminação por oligoelementos nos dois golfos tunisinos (Golfo de Gabes e Golfo de Tunísia) sobre os caranguejos nados azuis hepatopâncreas (Portunus segnis). Foram avaliadas as concentrações de três oligoelementos (cádmio, cobre e chumbo) no hepatopâncreas P.segnis. Além disso, os níveis de acetilcolinesterase (AChE), metalotioninas (MTs), peroxidase hidróxida (H2O2) e produtos de proteína de oxidação avançada (AOPP) foram escolhidos como medidas para avaliar os efeitos ambientais nas populações dos dois caranguejos de diferentes golfos. Macromoleculares (lipídios, proteínas e DNA) também foram determinados em P.segnis hepatopâncreas. Os resultados da bioacumulação de elementos vestigiais em P. segnis hepatopancreas mole mostraram uma alta poluição no Golfo de Gabes como evidência pelo acúmulo significativo de cádmio, cobre e chumbo. Estes resultados foram confirmados por aumentos significativos do índice de poluição de metais (MPI) e dos níveis de metalotioninas (MTs) no hepatopâncreas de P. segnis do Golfo de Gabes do que estes do Golfo de Tunísia. Consequentemente, o acúmulo de elementos vestigiais em P.segnis do Golfo de Gabes conduz à geração de processos de peroxidação lipídica, como documentado pelos altos níveis de H2O2e LOOH. Uma diminuição significativa da atividade de AChE foi registrada em caranguejos coletados do Golfo de Gabes em comparação com estes do Golfo de Tunísia. O presente estudo revelou esgotamento de proteínas e conteúdo de lipídios, enquanto o DNA mostrou degradação significativa no hepatopâncreas de caranguejo coletado do Golfo de Gabes em comparação com o Golfo de Tunísia. Estas evidências devem ser levadas em consideração ao utilizar P. segnis como uma espécie indicadora ecológica nos programas de biomonitoramento.

Narcissus tazetta (Amaryllidaceae) is a medicinal plant widely used for cut flowers and potted ornamental plant in Tunisia flora. The current study evaluated the phenolic composition and antioxidant properties of its flower extracts and investigated its potential protective activity against cadmium chloride (CdCl)–induced hepatotoxicity in mice. Mice were divided into six groups of six each: group 1, serving as negative controls, received by intraperitoneal way only distilled water; group 2 received by intraperitoneal way CdCl (0.16 mg/kg bw); groups 3 and 4 received CdCl at the same dose of group 2 and 100 or 200 mg/kg bw of Narcissus tazetta flower extracts via oral route; groups 5 and 6, serving as positive controls, received only Narcissus tazetta flower extracts. Polyphenolic compounds of the extract were analyzed by colorimetric and high-performance liquid chromatography-mass spectrometry (HPLC-MS) methods. Total antioxidant activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging potential of the extract were estimated using colorimetric method. Results indicated that ethanolic flower extract contained high levels of total phenolic and flavonoid along with a strong total antioxidant and DPPH free radical scavenging activities. HPLC-MS analysis identified eight phenolic compounds, including rutin, kaempferol glycosides, and chlorogenic acids. The extract also exhibited marked hepatoprotective effects against CdCl toxicity by reducing hepatic levels of malondialdehyde, advanced oxidation protein products, hydrogen peroxide, metallothioneins, and DNA degradation. Additionally, co-administration of Narcissus tazetta flower extracts lowered the plasma activities of transaminases, gamma glutamyl transpeptidase, and lactate dehydrogenase and increased hepatic levels of reduced glutathione, nonprotein thiols, vitamin C, and catalase activity. The hepatoprotective effects of the extract were demonstrated by histopathological improvement of liver disorders.

Coastal transitional waters are exposed to many anthropogenic threats. This study aims to assess the trace metals' pollution status of transitional waters by evaluating its biological effects in the clam Venerupis decussata. Among the studied sites along the Tunisian littoral, South Tunis and Boughrara were the most impacted, since clams from these two lagoons presented significant differences in: (i) trace metal contents, (ii) in-cell hydrogen peroxide, (iii) enzymatic and non-enzymatic defenses, (iv) damage to lipids and proteins, and (v) protein post-translational modifications. These changes related to evident histopathological traits. PCA showed a clear separation between the digestive gland and gills tissues and illustrated an impact gradient in Tunisian coastal lagoons. Water temperature was revealed as an added natural stressor that, when concurring with high pollution, may jeopardize an ecosystem's health and contribute to the accumulation of hazardous metals in organisms.