Percorrer por autor "Peixoto, Francisco P."
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- Antigenotoxic and cosmetic potential of elderberry (Sambucus nigra) extract: protection against oxidative DNA damagePublication . Gonçalves, Sara; Peixoto, Francisco P.; Silveira, Tayse F. F. da; Barros, Lillian; Gaivão, IsabelThe integrity of the genome is under constant threat from both endogenous and exogenous factors that induce oxidative stress and accelerate ageing. The demand for natural and organic cosmetics is rising due to the harmful effects of synthetic genotoxic agents on human health and the environment. Elderberry (Sambucus nigra L.), a fruit rich in bioactive compounds such as polyphenols, has demonstrated significant antioxidant properties. This study aimed to evaluate elderberry extract’s chemical characterization and biological activities in peripheral blood mononuclear cells exposed to streptonigrin and H2O2, both known for causing DNA damage. The antigenotoxic evaluation and antioxidant assays (ABTS and DPPH) were conducted to assess its biological properties. Using the Comet assay enhanced with formamidopyrimidine-DNA glycosylase (Fpg) to detect oxidized purines, we found that elderberry extract significantly reduced DNA damage. These findings suggest that elderberry has potential as a natural alternative to synthetic ingredients in cosmetics, offering protective benefits against DNA damage and contributing to antiageing and skin health.
- Antioxidant capacity and toxicological evaluation of pterospartum tridentatum flower extractsPublication . Ferreira, Fernanda M.; Dinis, Lia Tânia; Azedo, Pedro; Galhano, Cristina; Cardoso, Susana M.; Domingues, Maria R.M.; Pereira, Olívia R.; Simões, Anabela; Palmeira, Carlos M.; Peixoto, Francisco P.Pterospartum tridentatum Willk. (prickled broom) is an autochthonous plant, common in Portuguese territory. The yellow flowers are used in traditional medicine, as a potential cure for all body illnesses, mainly for throat irritation treatment or for diabetes, hypertension and hypercholesterolemia therapy.Despite its traditional use, no toxicological assessment has been performed as we know. A high antioxidant activity of P. tridentatum flower water extract was acessed in good agreement with its ESI-MS spectrum that revealed the presence of several flavonoids, as luteolin-O-(O-acetyl)-glucuronide, luteolin-O- glucuronide or isorhamnetin-O-hexoside. Mitocondrial respiratory rates (state 4, state 3 and FCCP-stimulated respiration) and respiratory indexes (respiratory control and P/O ratios) showed no consistent decrease of respiratory and phosphorylative efficiencies for the concentrations tested (up to 500 μg.mL-1). Cytotoxicity evaluation, using MTT assay, was reliable with the previous results. In conclusion, for the concentration range commonly used P. tridentatum flowers usage can be regarded as harmless and trustworthy.
- Bioaccumulation of heavy metals in Liza saliens from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Peixoto, Francisco P.; Salgado, Maria AntóniaHeavy metal (Cu and Zn) concentrations in liver, gills, and muscle of leaping grey mullet, Liza saliens, from the Portuguese Esmoriz–Paramos coastal lagoon were measured to evaluate their bioaccumulation as a function of sediment contamination. The highest metal concentrations were observed in the liver (254mg Cu kg 1) and gills (114 mgZn kg 1). Bioaccumulation factors (BAFs) were found to follow the order: Cu-liver4Cu-gills4Cu-muscle and Zn-gills4Zn-liver4Zn-muscle. The highest BAFs were observed in the organs mainly implicated in metal metabolism and a significant positive relationship was found between BAFs and fish age. These results suggest the loss of homeostatic capacity of L. saliens under chronic metal exposure leading to bioaccumulation. Furthermore, Cu-liver and Zngills accumulation can be good environmental indicators of metal stress in L. saliens
- Chaetomellic acid A treatment improves oxidative stress in rats with renal mass reductionPublication . Nogueira, António José M.; Oliveira, Paula A.; Colaço, Bruno Jorge; Oliveira, Maria; Peixoto, Francisco P.; Pires, Maria JoãoChaetomellic acid A (CA) is a potent and highly specific inhibitor of Ras farnesyl-protein transferase that has shown to decrease oxidative stress in rats with brain damage. Oxidative stress has been suggested to play an important role in the pathogenesis of chronic renal disease. Thus, the aim of this work was to evaluate the effect of chronic treatment with CA on oxidative stress in a model of renal mass reduction. Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been placed in four experimental groups: RMR rats without treatment (n=12); RMR rats treated with CA (n=8); SO rats without treatment (n=13); SO rats treated with CA (n=13). CA was intraperitoneally administered in a dose of 0.23 μg/Kg three times a week for six months. To evaluate the effect of CA on renal redox potential, the status of oxidative stress in renal tissues was determined. RMR was accompanied by a significant reduction in catalase and glutathione reductase (GR) activity, and a decrease in reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. CA administration significantly increased catalase and GR activity (p<0.05), and increased GSH/GSSG ratio, but no significant difference between the treated and no treated groups was found in this ratio. These data suggest that CA can attenuate 5/6 RMR-induced oxidative stress and therefore, contribute to prevention of progressive renal failure in chronic renal disease.
- The cyclooxigenase-2 inhibitor parecoxib prevents epidermal dysplasia in HPV16-transgenic mice: efficacy and safety observationsPublication . Ferreira, Tiago; Campos, Sandra; Silva, Mónica; Ribeiro, Rita; Santos, Susana; Almeida, José L.S.; Pires, Maria João; Costa, Rui Miguel Gil; Córdova, Cláudia; Nogueira, António José M.; Neuparth, Maria João; Medeiros, Rui; Bastos, Margarida M.S.M.; Gaivão, Isabel; Peixoto, Francisco P.; Oliveira, Maria Manuel; Oliveira, Paula A.Carcinogenesis induced by high-risk human papillomavirus (HPV) involves inflammatory phenomena, partially mediated by cyclooxigenase-2. In pre-clinical models of HPV-induced cancer, cyclooxygenase-2 inhibitors have shown significant e cacy, but also considerable toxicity. This study addresses the chemopreventive e ect and hepatic toxicity of a specific cyclooxigensase-2 inhibitor, parecoxib, in HPV16-transgenic mice. Forty-three 20 weeks-old female mice were divided into four groups: I (HPV16+/-, n = 10, parecoxib-treated); II (HPV16+/- n = 11, untreated); III (HPV16+/-, n = 11, parecoxib-treated) and IV (HPV16+/- n = 11, untreated). Parecoxib (5.0 mg/kg once daily) or vehicle was administered intraperitoneally for 22 consecutive days. Skin lesions were classified histologically. Toxicological endpoints included genotoxic parameters, hepatic oxidative stress, transaminases and histology. Parecoxib completely prevented the onset of epidermal dysplasia in HPV16+/- treated animals (0% versus 64% in HPV16+/- untreated, p = 0.027). Parecoxib decreases lipid peroxidation (LPO) and superoxide dismutase (SOD) activity and increases the GSH:GSSG ratio in HPV16+/- treated animals meaning that oxidative stress is lower. Parecoxib increased genotoxic stress parameters in wild-type and HPV16-transgenic mice, but didn’t modify histological or biochemical hepatic parameters. These results indicate that parecoxib has chemopreventive e ects against HPV16-induced lesions while maintaining an acceptable toxicological profile in this model.
- Cytinus hypocistis (L.) L. extract effects in an animal model of papillomavirus-induced neoplasiaPublication . Medeiros, Catarina; Silva, Ana Rita; Ferreira, Tiago; Barros, Lillian; Neuparth, Maria João; Peixoto, Francisco P.; Bastos, Margarida M.S.M.; Medeiros, Rui; Costa, Rui Miguel Gil; Pires, Maria João; Faustino-Rocha, Ana; Gama, Adelina; Oliveira, Paula A.Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeutic compounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals, 30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/ n+CH12.4); V (HPV+control) and VI (FVB/n+control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.
- Effect of a pterospartum tridentatum enriched phenolic extract in mitochondrial bioenergetic functionsPublication . Ferreira, Fernanda M.; Peixoto, Francisco P.; Pereira, Olívia R.; Dinis, Lia Tânia; Domingues, Maria R.M.; Crespí, António; Palmeira, Carlos M.; Cardoso, Susana M.Pterospartum tridentatum Willk. is an autochthonous and common plant in Portugal, locally known as ‘carqueija’. Leaves and stems are normally used in cooking, to flavour rice, roast meat or hunting animals and leaves are also used as condiment in fresh salads. Despite its traditional use, no evaluation in mitochondrial bioenergetics has been performed. P. tridentatum leaf extract phenolic composition was elucidated by electrospray ionization-mass spectrometry (ESI-MS). M. aquatica extract effects were evaluated over mitochondrial membrane potential by using a Clarktype oxygen electrode in the presence of succinate as respiratory substrate. Cytotoxicological effects of plant extracts were evaluated on HepG2 cells throughout MTT assay. The ESI-MS spectrum of P. tridentatum leaves aqueous extract revealed the presence of several luteolin and isorhamnetin derived phenolic compounds, which can be associated to the health benefits claimed for this plant species. Yet, P. tridentatum leaves extract (up to 100 lg plant extract mg protein _1) stimulated state 4 and FCCP-stimulated liver mitochondria respiratory rates and inhibited the state 3 respiratory rate. Hence, respiratory control ratios were diminished, indicating a phosphorylative efficiency decrease, due to inner mitochondrial membrane permeability induced by P. tridentatum leaves extract. Nevertheless, P/O ratios were not affected in the range of concentrations tested and cytotoxicity evaluation using MTT assay (50 and 125 ug plant extract) showed no significant decrease over HepG2 cell viability. This dual behaviour reflects the P. tridentatum hormetic effects over mitochondrial activity. Conclusion: Overall, the present study suggests that consumption of P. tridentatum leaves should be regarded as safe and present benefits concerning the modern lifestyles.
- Effect of pterospartum tridentatum enriched phenolic extract in mitochondrial bioenergetic functionsPublication . Ferreira, Fernanda M.; Peixoto, Francisco P.; Pereira, Olívia R.; Dinis, Lia Tânia; Domingues, Maria R.M.; Crespí, António; Palmeira, Carlos M.; Cardoso, Susana M.Pterospartum tridentatum Willk. is an autochthonous and common plant in Portugal, locally known as ‘carqueija’. Leaves and stems are normally used in cooking, to flavour rice, roast meat or hunting animals and leaves are also used as condiment in fresh salads. Despite its traditional use, no evaluation in mitochondrial bioenergetics has been performed. P. tridentatum leaf extract phenolic composition was elucidated by electrospray ionization-mass spectrometry (ESI-MS). M. aquatica extract effects were evaluated over mitochondrial membrane potential by using a Clarktype oxygen electrode in the presence of succinate as respiratory substrate. Cytotoxicological effects of plant extracts were evaluated on HepG2 cells throughout MTT assay. The ESI-MS spectrum of P. tridentatum leaves aqueous extract revealed the presence of several luteolin and isorhamnetin derived phenolic compounds, which can be associated to the health benefits claimed for this plant species. Yet, P. tridentatum leaves extract (up to 100 lg plant extract mg protein _1) stimulated state 4 and FCCP-stimulated liver mitochondria respiratory rates and inhibited the state 3 respiratory rate. Hence, respiratory control ratios were diminished, indicating a phosphorylative efficiency decrease, due to inner mitochondrial membrane permeability induced by P. tridentatum leaves extract. Nevertheless, P/O ratios were not affected in the range of concentrations tested and cytotoxicity evaluation using MTT assay (50 and 125 ug plant extract) showed no significant decrease over HepG2 cell viability. This dual behaviour reflects the P. tridentatum hormetic effects over mitochondrial activity. Conclusion: Overall, the present study suggests that consumption of P. tridentatum leaves should be regarded as safe and present benefits concerning the modern lifestyles.
- The effects of long-term chaetomellic acid a administration on renal function and oxidative stress in a rat model of renal mass reductionPublication . Nogueira, António José M.; Peixoto, Francisco P.; Oliveira, Maria Manuel; Pires, Carlos André; Colaço, Bruno Jorge; Oliveira, Paula A.; Pires, Maria JoãoThis study aimed to evaluate the effect of chronic treatment with chaetomellic acid A (CAA) on oxidative stress and renal function in amodel of renalmass reduction. Methods.MaleWistar ratswere subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been divided into four experimental groups: RMR: RMR rats without treatment (n = 14); RMR + CAA: RMR rats treated with CAA (n = 13); SO: SO rats without treatment (n = 13); and SO + CAA: SO rats treated with CAA (n = 13). CAA was intraperitoneally administered in a dose of 0.23 μg/Kg three times a week for six months. Results. RMR was accompanied by a significant reduction in catalase and glutathione reductase (GR) activity (p < 0.05) and a decrease in reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. CAAadministration significantly increased catalase andGR activity (p < 0.05) and increased GSH/GSSG ratio, but no significant difference between the treated and nontreated groups was found in this ratio.No significant differences were found between theRMRgroups in any of the parameters of renal function.However, CAA administration slightly improves some parameters of renal function. Conclusions. These data suggest that CAA could attenuate 5/6 RMR-induced oxidative stress.
- Fatty acid characterization of cyanobacterial strains isolated from Vela lake and Mondego river rice fields (central-western, Portugal)Publication . Galhano, Victor; Santos, H.; Geraldes, Ana Maria; Figueiredo, Daniela R.; Crespí, António; Gomes-Laranjo, José; Peixoto, Francisco P.
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