Universidade Federal De Santa Maria Centro Ciências Naturais e Exatas Programa De Pós-Graduação Em Ciências Biológicas: Bioquimica Toxicológica (original) (raw)
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INCT-APA Annual Activity Report, 2010
In the present study, we aimed to investigate the toxic effects of Prasiola crispa extract on a fruit fly (Drosophila melanogaster) model. Toxicity was assessed as % mortality, negative geotaxis behaviour and acetylcholine esterase (AchE), glutathione S-transferase (GST), catalase (CAT) activities as well as glutathione content (GSH) and hydroperoxide formation. Administration of algae extract (2 mg/mL) to flies for 24 hours resulted in a massive increase in mortality (7.6 fold increase, compared to control). A significant increase in climbing performance, indicating an alteration in negative geotaxis behaviour, was also observed. The AchE activity was unchanged after algae extract treatment for 24 hours. However, GST activity was significantly increased after Prasiola crispa administration. The CAT activity was significantly diminished in flies that received algae extract for 24 hours. Glutathione levels and hydroperoxide formation remained unchanged. Our results show for the first time the toxic effects of an Antarctic algae extract in Drosophila melanogaster. The insecticide action of Prasiola crispa may be related to changes on vital antioxidant systems. Further studies are necessary to elucidate the exact mechanisms of toxicity of this Antarctic alga to Drosophila melanogaster.
INCT-APA Annual Activity Report, 2013
In a previous report we tested the insecticidal e ect of a crude extract of Prasiola crispa. In the present study, we obtained three di erent fractions and tested which of them presents higher toxicity on a fruit y (Drosophila melanogaster) model. Fraction 1 (ethanol), Fraction 2 (methanol) and Fraction 3 (ethyl acetate) we administered to ies for 48 hours at concentrations of 0, 1, 2, 5, 10 and 50 µg/ml in a 1% sucrose solution. Sucrose alone was used as control. Toxicity was assessed as % mortality and negative geotaxis behavior. A signi cant decrease in survivability of ies exposed to Fraction 1 and 2 at the higher concentrations tested was observed, while Fraction 3 posed a signi cant increase in mortality also at intermediate concentrations. e comparison between the three fractions showed that Fraction 3 was signi cantly most prominent in inducing mortality. Similar results were observed for the climbing performance, indicating an alteration in negative geotaxis behavior. In our previous report we showed that Prasiola crispa crude extract presents high toxicity to Drosophila melanogaster. Our present results show that Fraction 3 may contain high concentrations of toxic metabolites compared to other two fractions. Further studies are necessary to elucidate the exact mechanisms of toxicity of this Antarctic alga to Drosophila melanogaster and to identify which components of Fraction 3 are responsible for such an e ect.
Oxidative Medicine and Cellular Longevity, 2021
The biological and therapeutic properties of seaweeds have already been well known. Several studies showed that among the various natural marine sources of antioxidants, seaweeds have become a potential source of antioxidants because of their bioactive compounds. Most of the metabolic diseases are caused by oxidative stress. It is very well known that antioxidants have a pivotal role in the treatment of those diseases. Recent researches have revealed the potential activity of seaweeds as complementary medicine, which have therapeutic properties for health and disease management. Among the seaweeds, brown seaweeds (Phaeophyta) and their derived bioactive substances showed excellent antioxidant properties than other seaweeds. This review focuses on brown seaweeds and their derived major bioactive compounds such as sulfated polysaccharide, polyphenol, carotenoid, and sterol antioxidant effects and molecular mechanisms in the case of the oxidative stress-originated disease. Antioxidants have a potential role in the modification of stress-induced signaling pathways along with the activation of the oxidative defensive pathways. This review would help to provide the basis for further studies to researchers on the potential antioxidant role in the field of medical health care and future drug development.
Nutrition and Cancer, 2020
The marine ecosystem is considered as a treasure of numerous novel biologically active molecules. We investigated the anticancer potential of the phenolic extract of Halophila ovalis in breast cancer (MCF-7) cells and characterized the possible underlying molecular mechanism. The phenolic extract (5 ml) of H. ovalis effectively inhibited the growth of MCF-7 cells. The results of DAPI staining indicated that this phenolic extract potently induces apoptosis in MCF-7 cells which was observed by increased chromatin condensation in the treated cells. An increased expression of the active fragments of an executioner caspase, caspase 3 in phenolic extract-treated MCF-7 cells further confirms this apoptosis induction. In consequence, the loss of mitochondrial membrane potential was noticed in treated cells. The protein expression analyzes show decreased expression of the anti-apoptotic protein, Bcl-2, and DNA repair enzyme, PARP in treated cells indicating the probable molecular targets of apoptosis. Further, the phenolic extract of H. ovalis blocked the antioxidant defense system in MCF-7 cells by down-regulating the protein expression of a major transcription factor, Nrf-2 and regulatory antioxidant enzymes, SOD-2 and HO-1. These results show the presence of chemopreventive compound(s) in the phenolic extract, which offers a platform for future studies to identify the active principles.
Pharmaceutical Biology, 2016
Context Seaweeds from the Mexican Pacific Ocean have not been evaluated as a source of chemoprotectants. Objective The objective of this study is to evaluate chemopreventive activities of the seaweeds Phaephyceae-Padina durvillaei (Dictyotaceae)-Rodhophyceae-Spyridia filamentosa (Spyridiaceae), Gracilaria vermiculophylla (Gracilariaceae)-and Chlorophyceae-Ulva expansa (Ulvaceae), Codium isabelae (Codiaceae), Rhizoclonium riparium (Cladophoraceae) and Caulerpa sertularioides (Caulerpaceae). Materials and methods Methanol, acetone and hexane seaweed extracts were assessed at 30 and 3 mg/mL on antioxidant capacity (DPPH and ABTS assays), 0.003-3.0 mg/plate on antimutagenic activity against AFB 1 using Salmonella typhimurium TA98 and TA100 tester strains in Ames test, and 12.5 to 100 mg/mL on antiproliferative activity on Murine B-cell lymphoma. Phenols, flavonoids and pigments content were also assessed as antioxidant compounds. Results Extraction yield was higher in methanol than in acetone and hexane extracts (6.4, 2.7 and 1.4% dw). Antioxidant capacity was higher in brown and green than in red seaweed species, particularly in P. durvillaei extracted in acetone (EC 50 value¼ 16.9 and 1.56 mg/mL for DPPH and ABTS). Flavonoids and chlorophylls were identified as mainly antioxidant components; particularly in hexane extracts, which were correlated with the antioxidant capacity. Highest mutagenesis inhibition (440%) occurred in R. riparium at the lowest concentration assayed (0.003 mg/plate), while highest antiproliferative inhibition (37 and 72% for 12.5 and 25 mg/mL) occurred in C. sertularioides. Discussion and conclusion Flavonoids and chlorophylls explained the chemopreventive activities assessed in S. filamentosa, R. riparium and C. sertularioides. These seaweeds have a high potential as a source of novel chemoprotectants.
In Vitro Antioxidant Activity of Selected Seaweeds in the Philippines
2017
The increasing amount of free radicals in the environment from both exogenous and endogenous sources make intake of antioxidants essential. This study focused on investigating the antioxidant properties of acetone, chloroform, and ethanol extracts of four seaweeds commonly found in the Philippines, namely: Caulerpa lentillifera, Caulerpa racemosa, Kappaphycus alvarezii, and Hydropuntia edulis using the DPPH assay. Results show that all seaweed samples exhibited antioxidant activities in all solvents used. Results show that all seaweed samples showed significant antioxidant activity. Between the two batches of collection of C. lentillifera and K. alvarezii, batch 1, which was collected in October 2016, showed significantly higher antioxidant activity in comparison to the activity of batch 2, which was collected in January 2017. With regards to the solvents used, acetone extracts demonstrated the highest antioxidant activity among all seaweed species. Results of the study can help fur...
Antioxidant and anti-cancer activities of brown and red seaweed extracts from Chilean coasts
This study evaluates the content of polyphenols, flavonoids and anthraquinones from sequential extracts from four algae species from along the Chilean coastline: Desmarestia ligulata, Dictyota kunthii, Laurencia chilensis and Chondracanthus chamissoi. The antioxidant capacity of these extracts was evaluated through three complementary assays: the TRAP, FRAP, and DPPH assays. Additionally, the cytotoxic activity of these extracts was determined through sulforhodamine B assays on two cancer cell lines, one colon (HT-29) and one breast (MCF-7), and one non-tumor control group of epithelial colon cells (CoN). The greatest antioxidant activity was detected in the ethyl acetate and dichloromethane extracts from L. chilensis in its TRAP potential, ethyl acetate of D. kunthii in its FRAP potential, and finally D. ligulata in its DPPH radical scavenging activity. The activities of this D. ligulata and L. chilensis extracts were significantly correlated with their flavonoid contents. In addition, the dichloromethane extracts from D. kunthii and C. chamissoi showed strong cytotoxic activity against HT-29 and MCF-7; however, the activity was not selective. Future research is necessary to purify the bioactive compounds of interest and improve their selectivity for eventual therapeutic use.
Sustainable Marine Structures
Seaweed is an enormous resource comprised with natural bioactive compounds comprise with several therapeutic effects including anticancer activity. In this context, the biochemical composition of seaweeds plays a major role. Many biochemical compounds extracted from seaweeds and crude extracts, such as aqueous, methanolic account mainly for the anticancer effect against several cancer cell line. In this contrast seaweed extracts inhibit cancer cell growth and proliferation by inducing apoptosis and inhibit metastasis activity. In this review, biochemical and anticancer properties of seaweeds are discussed and this will provide the basic information to develop a novel chemotherapeutic drug to challenge the cancer.
Advances in Environmental Biology
Background: Food antioxidants have been considered as effective agents to reduce oxidative stress which can lead to cancer. Objective: The aim of this study was to investigate the potential cytotoxic effect of antioxidant extracts of two commonly found seaweeds namely Kappaphycus alvarezii and Kappaphycus striatum against hepatocarcinoma HepG2 cell. Methods: Cell viability was evaluated by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Annexin V-FITC/PI flowcytometry assay was used to determine the cell death mode of HepG2 cells treated by K. alvarezii and K. striatum extracts. Results: The IC50 concentration of K. alvarezii and K. striatum extracts that inhibit the proliferation of hepatocarcinoma HepG2 cells was 1.8 mg/mL and 0.9 mg/mL respectively. This finding showed that the antioxidant extracts of K. striatum exhibited better antiproliferative effect against hepatocarcinoma HepG2 cell than the antioxidant extracts of K. alvarezii. However, usin...
Vojnosanitetski pregled, 2020
Background/Aim. Rumex crispus (curly dock) is a wild perennial herbaceous plant, which products are considered as a rich source of biologically active molecules with antioxidant and cytotoxic activities. The aim of this study was to estimate of antioxidant and cytotoxic activities of aqueous extract of curly dock fruits. Methods. The aqueous extract of curly dock fruits was evaluated for its antioxidant activity by in vitro assays for ferric-reducing antioxidant power (FRAP), NO•, OH• and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activities and the influence on lipid per-oxidation in liposomes. The cytotoxicity of tested extract was examined in vitro in human cervix carcinoma (HeLa), colon adenocarcinoma (HT-29) and breast adenocarcinoma (MCF7) cells. Results. The tested extract showed a potential antioxidant activity manifested in scavenging of free radicals as well as an ability to decrease lipid peroxidation in li-posomes. The results indicated tissue-selective cytotoxicity of R. crispus fruit extract in vitro. The most prominent anti-tumor activity was observed towards HeLa and MCF7 cell lines. Conclusion. The investigated aqueous fruit extract of R. crispus had potential antioxidant and cytotoxic activities, with necrosis as a main mechanism of induced cell-death. Different methods of extraction of R. crispus fruits, apart from aqueous, are recommended for further investigations.