Browsing by Author "Laufer, Stefan"
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- Adjunctive role of Calyptranthes tricona extract with probiotic Kluyveromyces marxianus on colorectal adenocarcinoma Caco-2 cellsPublication . Kich, Débora Mara; Bitencourt, Shanna; Faleiro, Dalana; Immich, Sheila Mariele; Marmitt, Diorge Jonatas; Baldasso, Tamara; Haute, Gabriela Viegas; Oliveira, Jarbas Rodrigues de; Laufer, Stefan; Pedrosa, Rui; Souza, Claucia Fernanda Volken de; Goettert, Márcia InêsThe composition of microbiota may influence the development of colorectal cancer (CRC). In addition, probiotics can decrease the chance of developing cancer or its progress. For that reason, it is encouraging to assess the influence of plant extracts as adjuvants of the health-promoting effects of probiotics. Thus, this study aimed to investigate the in vitro beneficial properties of Calyptranthes tricona leaf ethanol extract in association or not with the lactic yeast Kluyveromyces marxianus on colon adenocarcinoma Caco-2 cells. C. tricona extract inhibited the in vitro p38α MAPK activity and exhibited immunomodulation on isolated human lymphocytes. Further, the extract did not induce cytotoxicity towards K. marxianus or Caco-2 cells; leading to an increased yeast adhesion to cells in a dose-dependent manner. In conclusion, this preliminary study demonstrates that C. tricona extract has effects on enzyme inhibition and immune function. In addition, when associated with K. marxianus, C. tricona may possess beneficial properties for application as enhancer of probiotic’s protective role on CRC cells. However, further studies are necessary in order to elucidate the mechanisms involved.
- Antimicrobial and antileukemic effects: in vitro activity of Calyptranthes grandifolia aqueous leaf extractPublication . Majolo, Fernanda; Bitencourt, Shanna; Monteiro, Bruna Wissmann; Haute, Gabriela Viegas; Alves, Celso; Silva, Joana; Pinteus, Susete; Santos, Roberto Christ Vianna; Torquato, Heron Fernandes Vieira; Paredes-Gamero, Edgar Julian; Oliveira, Jarbas Rodrigues; Souza, Claucia Fernanda Volken De; Pedrosa, Rui; Laufer, Stefan; Goettert, Márcia InêsNatural products are still a promising source of bioactive molecules. Food and Drug Administration data showed that approximately 49% of the approved molecules originate naturally or chemicallyresemble these substances, of which more than 70% are being used in anticancer therapy. It is noteworthy that at present there are no scientific studies to prove the effectiveness and safety of a number of plants used in folk medicine such as in the case of Calyptranthes grandifolia O. Berg (Myrtaceae) originally from South America. The aim of the present study was to determine the biological potential and toxicological effects of the aqueous leaf extract of C. grandifolia. The main detected phytoconstituents were condensed tannins and flavonoids and a high quantity of polyphenols. Regarding the antimicrobial potential, the extract exerted inhibitory activity against Pseudomonas aeruginosa. The results also revealed the extract induced DNA damage in a concentration-dependent manner in RAW 264.7 cells. In addition, C. grandifolia produced cytotoxicity in leukemia cell lines (HL60 and Kasumi-1) without affecting isolated human lymphocytes but significantly inhibited JAK3 and p38α enzyme activity. Taken together, these findings add important information on the biological and toxicological effects of C. grandifolia, indicating that aqueous extract may be a source of natural antimicrobial and antileukemic constituents.
- Antiulcerogenic potential of the ethanolic extract of Ceiba speciosa (A. St.-Hil.) Ravenna evaluated by in vitro and in vivo studiesPublication . Dörr, Juliana Andréa; Majolo, Fernanda; Bortoluzzi, Luísa; Vargas, Evelin Zen de; Silva, Joana; Pasini, Manoela; Stoll, Stefani Natali; Rosa, Rafael Lopes da; Figueira, Mariana Moreira; Fronza, Marcio; Beys-da-Silva, Walter O.; Martins, Alice; Gaspar, Helena; Pedrosa, Rui; Laufer, StefanGastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa provoked by several factors. This stomach injury is regulated by many inflammatory mediators and is commonly treated with proton-pump inhibitors, histamine H2 receptor blockers and antacids. However, various medicinal plants have demonstrated positive effects on gastric ulcer treatment, including plants of the Ceiba genus. The aim of this study was to evaluate the antiulcer and anti-inflammatory activities of the stem bark ethanolic extract of Ceiba speciosa (A. St.-Hil.) Ravenna. We performed a preliminary quantification of phenolic compounds by high-performance liquid chromatography-diode array detection (HPLC-DAD), followed by the prospection of other chemical groups through nuclear magnetic resonance (NMR) spectroscopy. A set of in vitro assays was used to evaluate the extract potential regarding its antioxidant activity (DPPH: 19.83 +- 0.34 ug/mL; TPC: 307.20 +- 6.20 mg GAE/g of extract), effects on cell viability and on the release of TNF-α in whole human blood. Additionally, in vivo assays were performed to evaluate the leukocyte accumulation and total protein quantification in carrageenan-induced air pouch, as well as the antiulcerogenic effect of the extract on an ethanol-induced ulcer in rats. The extract contains flavonoids and phenolic compounds, as well as sugars and quinic acid derivatives exhibiting potent antioxidant activity and low toxicity. The extract reduced the release of TNF-α in human blood and inhibited the activity of p38α (1.66 ug/mL), JAK3 (5.25 ug/mL), and JNK3 (8.34 ug/mL). Moreover, it reduced the leukocyte recruitment on the pouch exudate and the formation of edema, reverting the effects caused by carrageenan. The extract presented a significant prevention of ulcer formation and a higher reduction than the reference drug, Omeprazole. Therefore, C. speciosa extract has demonstrated relevant therapeutic potential for the treatment of gastric diseases, deserving the continuation of further studies to unveil the mechanisms of action of plant bioactive ingredients.
- In vitro activities of Ceiba speciosa (A.St.-Hil) Ravenna aqueous stem bark extractPublication . Dörr, Juliana Andréa; Bitencourt, Shanna; Bortoluzzi, Luísa; Alves, Celso; Silva, Joana; Boligon, Aline Augusti; Santos, Roberto Christ Vianna; Laufer, Stefan; Pedrosa, Rui; Goettert, Márcia InêsSeveral species of the genus Ceiba (Malvaceae) are ethnopharmacologically used. Thus, this study aimed to investigate the in vitro beneficial properties of the aqueous stem bark extract of Ceiba speciosa. The extract presented a great amount of phenolic compounds (117.4 ± 6.2 mg GAE/g). The antioxidant activity was assessed by DPPH (IC50 = 42.87 μg/mL), ORAC (2351.17 μmol TE/g) and FRAP (235.94 μM FeSO4/g) methods. In addition, the extract reduced MCF-7 cell viability as assessed by MTT. However, it prevented mitochondrial membrane depolarization and reduced caspase-9 activity induced by hydrogen peroxide. In conclusion, these findings indicate the extract is an excellent source of natural antioxidants and is able to protect ROS-induced cell death. Therefore, C. speciosa extract may possess beneficial properties for application in pharmaceutical industry as an antioxidant. However, further studies to better elucidate its mechanisms and to isolate its active compounds are required.
- Neuromodulatory effects of Calyptranthes grandifolia extracts against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y cellsPublication . Kich, Débora Mara; Bitencourt, Shanna; Alves, Celso; Silva, Joana; Pinteus, Susete; Pedrosa, Rui; Laufer, Stefan; Souza, Claucia Fernanda Volken de; Goettert, Márcia InêsAlzheimer’s and Parkinson's diseases are neurodegenerative disorders characterized by progressive neuronal dysfunction. Previous studies revealed that some natural products have neuroprotective properties, including species of the Myrtaceae family. However, the neuromodulatory potential of Calyptranthes grandifolia is not clear. In the present study, we examined the ability of the ethanol and hexane leaf extracts of C. grandifolia to prevent 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro. Initially, we investigated the potential of the extracts to inhibit the neurodegenerative-related enzymes c-Jun N-terminal kinase 3 (JNK3) and acetylcholinesterase (AChE). In addition, SH-SY5Y cell viability was assessed by MTT assay after 100 mM 6-OHDA-induced cell damage. In order to verify the possible effects of both extracts on 6-OHDA-induced cell death, hydrogen peroxide generation, mitochondrial potential and caspases-3 activity were assessed. Our findings revealed that ethanol extract exhibited inhibitory activity against JNK3 and AChE. In addition, when co-treating SH-SY5Y cells with 6-OHDA and the extracts, oxidative stress was inhibited by both extracts through a decrease of mitochondrial depolarization and caspases-3 activity. In summary, ethanol and hexane extracts of C. grandifolia have some suppressive property against neurotoxicity induced by 6-OHDA.
- Neuroprotective effect of Luteolin-7-O-Glucoside against 6-OHDA-induced damage in undifferentiated and RA-differentiated SH-SY5Y cellsPublication . Rehfeldt, Stephanie Cristine Hepp; Silva, Joana; Pinteus, Susete; Pedrosa, Rui; Alves, Celso; Laufer, Stefan; Goettert, Márcia InêsLuteolin is one of the most common flavonoids present in edible plants and its potential benefits to the central nervous system include decrease of microglia activation, neuronal damage and high antioxidant properties. The aim of this research was to evaluate the neuroprotective, antioxidant and anti-inflammatory activities of luteolin-7-O-glucoside (Lut7). Undifferentiated and retinoic acid (RA)-differentiated SH-SY5Y cells were pretreated with Lut7 and incubated with 6-hydroxydopamine (6-OHDA). Cytotoxic and neuroprotective effects were determined by MTT assay. Antioxidant capacity was determined by DPPH, FRAP, and ORAC assays. ROS production, mitochondrial membrane potential (DYm), Caspase–3 activity, acetylcholinesterase inhibition (AChEI) and nuclear damage were also determined in SH-SY5Y cells. TNF- , IL-6 and IL-10 release were evaluated in LPS-induced RAW264.7 cells by ELISA. In undifferentiated SH-SY5Y cells, Lut7 increased cell viability after 24 h, while in RA-differentiated SH-SY5Y cells, Lut7 increased cell viability after 24 and 48 h. Lut7 showed a high antioxidant activity when compared with synthetic antioxidants. In undifferentiated cells, Lut7 prevented mitochondrial membrane depolarization induced by 6-OHDA treatment, decreased Caspase-3 and AChE activity, and inhibited nuclear condensation and fragmentation. In LPS-stimulated RAW264.7 cells, Lut7 treatment reduced TNF- levels and increased IL-10 levels after 3 and 24 h, respectively. In summary, the results suggest that Lut7 has neuroprotective effects, thus, further studies should be considered to validate its pharmacological potential in more complex models, aiming the treatment of neurodegenerative diseases.
- Neuroprotective potential of Myrciaria plinioides D. Legrand extract in an in vitro human neuroblastoma modelPublication . Marmitt, Diorge Jonatas; Alves, Celso; Silva, Joana; Pinteus, Susete; Schneider, Taiane; Santos, Roberto Christ Vianna; Freitas, Elisete Maria de; Pedrosa, Rui; Laufer, Stefan; Goettert, Márcia InêsNeurodegenerative diseases are multifactorial debilitating disorders of the nervous system affecting approximately 30 million individuals worldwide. Mitochondrial dysfunction and oxidative stress have also been implicated in causing neurodegeneration. As life expectancy is increasing, neurodegenerative disorders are becoming a major social issue. None of the drugs currently available for treatment are capable of healing the patient. This means that new molecules should be explored. Plants have been used for treatment of countless medical conditions and extensive research is being carried out on species of the Myrtaceae family, widely used in traditional medicine. To date, Myrciaria plinioides D. Legrand has not been studied for its therapeutic use. To evaluate the neuroprotective effect of aqueous and ethanol extracts of this plant, we investigated the protective effects in human neuroblastoma cells (SH-SY5Y). High-performance liquid chromatography fingerprinting of extracts revealed the presence of phenolic compounds and flavonoids. Extracts showed antioxidant activity in the ORAC, DPPH, FRAP and GAE methods. Ethanol extract presented a strong inhibitory activity toward p38 and JNK3 MAPKs and AChE activity and also toward TNF-α release in human whole blood. None of the extracts significantly affected cell viability; the ethanol extract, however, reversed 6-OHDA-induced toxicity. Particularly the ethanol extract suggests neuroprotective effects by preventing membrane depolarization and by significantly decreasing H2O2 production and caspase-3 activity. The present results indicate that the ethanol extract protects SH-SY5Y cells against oxidative damage and apoptosis, as shown by the antioxidative activity of the extract as well as by the inhibition of important proteins such as caspase-3, p38 and JNK3 and the cytokine TNF-α.