Browsing by Author "Vala, Helena"
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- Aloysia citrodora extract as a chemopreventive agent against HPV16-induced lesions: findings from K14-HPV16 micePublication . Medeiros-Fonseca, Beatriz; Faustino-Rocha, Ana; Silva, Jessica; Silva, Mónica; Pires, Maria João; Neuparth, Maria João; Vala, Helena; Vasconcelos-Nóbrega, Cármen; Dias, Maria Inês; Barros, Lillian; Gonçalves, Lio; Gaivão, Isabel; Bastos, Margarida M.S.M.; Félix, Luís; Venâncio, Carlos; Medeiros, Rui; Costa, Rui Miguel Gil; Oliveira, Paula A.Aloysia citrodora has a long history of traditional use in treating various ailments. This study evaluated the in vivo chemopreventive efficacy and systemic toxicity of an extract of A. citrodora in a transgenic mouse model of HPV16 (human papillomavirus type 16)-induced cancer. Methods: The experiment involved six groups (n = 5): group 1 (G1, wild-type (WT), water), group 2 (G2, HPV, water), group 3 (G3, WT, 0.013 g/mL), group 4 (G4, HPV, 0.006 g/mL), group 5 (G5, HPV, 0.008 g/mL), and group 6 (G6, HPV, 0.013 g/mL). Throughout the assay, humane endpoints, body weight, food, and water consumption were recorded weekly. The internal organs and skin of the mice were collected for analysis after they were sacrificed. Toxicological parameters that were studied included hematological and biochemical blood markers, splenic and hepatic histology, and hepatic oxidative stress. Results: A. citrodora extract seems to reduce the incidence of dysplastic and in situ carcinoma skin lesions induced by HPV16 in this model, suggesting that dietary supplementation with concentrations of 0.008 g/mL and 0.013 g/mL may have beneficial chemopreventive effects. Conclusions: The extract did not induce any concentration-dependent toxicological effects on any of the parameters included in the study, indicating a favorable toxicological profile under these experimental conditions.
- Effect of chronic therapy with chaethomellic acid A on renal fibrosis in 5/6 nephrectomized rats: a preliminary studyPublication . Nogueira, António José M.; Vala, Helena; Nóbrega, Carmen; Pires, Carlos André; Colaço, Bruno Jorge; Oliveira, Paula A.; Pires, Maria JoãoThe high prevalence of chronic kidney disease underscores the failure to provide therapies to effectively halt, prevent, and/or reverse renal fibrosis. Thus, the aim of this study was to evaluate the effect of chronic treatment with chaethomellic acid A (CA) on renal fibrosis associated to 5/6 nephrectomy. Methods: Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats were placed in four experimental groups: RMR: rats without treatment (n=13); RMR+CA: rats treated with CA (n=13); SO: rats without treatment (n=13); SO+CA: 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. Renal samples were scored for the following lesions: glomerulosclerosis, interstitial fibrosis, arteriolosclerosis and interstitial inflammation. Results: Animals from the SO and SO+CA groups presented no kidney histological changes. Glomerulosclerosis, interstitial fibrosis and arteriolosclerosis scores were significantly lower (p< 0.001) in RMR+CA group when compared with RMR group. There were no significantly differences in interstitial inflammation score between RMR+CA and RMR groups. Conclusions: This preliminary data suggests that pharmacological inhibition of Ras (small GTPase proteins) activation may be a future strategy in the prevention of renal fibrosis.
- Exploring the therapeutic potential of Quercus ilex acorn extract in papillomavirus-induced lesionsPublication . Medeiros-Fonseca, Beatriz; Faustino-Rocha, Ana; Pires, Maria João; Neuparth, Maria João; Vala, Helena; Vasconcelos-Nóbrega, Cármen; Gouvinhas, Irene; Barros, Ana Novo; Dias, Maria Inês; Barros, Lillian; Bastos, Margarida M.S.M.; Gonçalves, Lio; Félix, Luís; Venâncio, Carlos; Medeiros, Rui; Costa, Rui Miguel Gil; Oliveira, Paula A.Papillomaviruses (PVs) infections have been documented in numerous animal species across different regions worldwide. They often exert significant impacts on animal health and livestock production. Scientists have studied natural products for over half a century due to their diverse chemical composition, acknowledging their value in fighting cancer. Acorns (Quercus ilex) are believed to have several unexplored pharmacological properties. This study aimed to evaluate the in vivo safety and cancer chemopreventive activity of an infusion extract of Q. ilex in a transgenic mouse model of human PV (HPV)-16, which developed squamous cell carcinomas through a multistep process driven by HPV16 oncogenes. Q. ilex extract was prepared by heating in water at 90°C and then characterized by mass spectrometry. Phenolic compounds from this extract were administered in drinking water to female mice in three different concentrations (0.03, 0.06, and 0.09 g/mL) over a period of 28 consecutive days. Six groups (n = 6) were formed for this study: group 1 (G1, wildtype [WT], water), group 2 (G2, HPV, water), group 3 (G3, WT, 0.09 g/mL), group 4 (G4, HPV, 0.03 g/mL), group 5 (G5, HPV, 0.06 g/ mL), and group 6 (G6, HPV, 0.09 g/mL). Throughout the experiment, humane endpoints, body weight, food intake, and water consumption were recorded weekly. Following the experimental period, all mice were sacrificed, and blood, internal organs, and skin samples were collected. Blood was used to measure glucose and microhematocrit and later biochemical parameters, such as creatinine, urea, albumin, alanine aminotransferase, and total proteins. Histological analysis was performed on skin and organ samples. The administration of Q. ilex extract resulted in a statistically significant increase in relative organ weight among HPV transgenic animals, indicating adaptive biological response to the tested concentrations. Moreover, a reduction in characteristic skin lesions was observed in animals treated with the 0.06 and 0.09 g/mL extract. These results provide a favorable chemopreventive profile for Q. ilex extract at concentrations of 0.06 and 0.09 g/mL. This study highlights the potential of Q. ilex extract as a safe and effective therapeutic strategy against HPV16- associated lesions in transgenic mouse models. The limitation of our study was the durability of transgenic animals. As a more sensitive species, we must always be careful with the durability of the test. We intend to study concentrations of 0.06 and 0.09 g/mL for longer to further investigate their possible effects.
- Long-term treatment with chaethomellic acid A reduces glomerulosclerosis and arteriolosclerosis in a rat model of chronic kidney diseasePublication . Nogueira, António José M.; Vala, Helena; Vasconcelos-Nóbrega, Cármen; Rocha, Ana Isabel Faustino; Pires, Carlos André; Colaço, Aura; Oliveira, Paula A.; Pires, Maria JoãoThe high prevalence of end-stage renal disease emphasizes the failure to provide therapies to effectively prevent and/or reverse renal fibrosis. Therefore, the aim of this study was to evaluate the effect of long-term treatment with chaethomellic acid A (CAA), which selectively blocks Ha-Ras farnesylation, on renal mass reduction-induced renal fibrosis. Male Wistar rats were sham-operated (SO) or subjected to 5/6 renal mass reduction (RMR). One week after surgery, rats were placed in four experimental groups: SO:SO rats without treatment (n = 13); SO + CAA: SO rats treated with CAA (n = 13); RMR:RMR rats without treatment (n = 14); and RMR + CAA:RMR 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. Renal fibrosis was evaluated by two-dimensional ultrasonography and histopathological analysis. The kidneys of the RMR animals treated with CAA showed a significantly decrease in the medullary echogenicity (p < 0.05) compared with the RMR rats that received no treatment. Glomerulosclerosis and arteriolosclerosis scores were significantly lower (p < 0.001) in the RMR + CAA group when compared with the RMR group. There were no significant differences in interstitial fibrosis, interstitial inflammation and tubular dilatation scores between the RMR + CAA and RMR groups. These data suggest that CAA can be a potential future drug to attenuate the progression of chronic kidney disease.
- New therapeutic approaches to chronic kidney diseasePublication . Nogueira, António José M.; Vala, Helena; Nóbrega, Carmen; Pires, Carlos André; Colaço, Bruno Jorge; Oliveira, Paula A.; Pires, Maria JoãoThe main research goal in patients with chronic kidney disease (CKD) is the development of new therapeutic approaches capable of slowing down the progression to end-stage renal disease. The aim of this work was to evaluate the effects of long-term administration of chaetomellic acid A (CAA), which selectively blocks H-Ras farnesylation, on chronic kidney lesions in 5/6 nephrectomized Wistar rats, an animal model of chronic renal disease. Materials and Methods: Sixty male Wistar rats were sham-operated (SO) or submitted to 5/6 nephrectomy (RMR). One week after surgery, surviving animals were distributed into four groups: SO–SO rats receiving no treatment (n = 13); SO+CAA–SO rats receiving CAA treatment (n = 13); RMR–RMR rats receiving no treatment (n = 14); RMR+CAA–RMR rats receiving CAA treatment (n = 13). CAA was administered intraperitoneally three times a week for 6 months. Renal fibrosis was evaluated by ultrasonography and histopathological analysis. All experimental procedures followed the European (European Directive 2010/63/EU) and National (Decree-Law 113/2013) legislation on the protection of the animals used for scientific purposes. Results: The kidneys of the RMR animals treated with CAA showed a significant decrease in medullary echogenicity (P <0.05) compared with the RMR rats that received no treatment. Glomerulosclerosis and arteriolosclerosis scores were significantly lower (P <0.001) in the RMR+CAA group when compared with the RMR group. Conclusion: These data suggest that pharmacological inhibition of H-Ras proteins activation may be a future strategy in the prevention of end-stage renal disease.
- Pulmonary and Gastrointestinal Parasitic Infections in Small Ruminant Autochthonous Breeds from Centre Region of Portugal—A Cross Sectional StudyPublication . Pereira, Maria; Vila-Viçosa, Maria João M.; Coelho, Catarina; Santos, Carla; Esteves, Fernando; Cruz, Rita; Gomes, Liliana; Henriques, Diogo; Vala, Helena; Nóbrega, Carmen; Mega, Ana; Melo, Carolina de; Malva, Madalena; Braguez, Joana; Mateus, TeresaThe production of small ruminant autochthonous breeds in the Centre region of Portugal is practiced in a semi-extensive husbandry system, exposing animals to parasitic infections. The main objective of this study was to estimate the prevalence of lungworm infection and identify risk factors. Fecal samples of 203 goats and 208 sheep from 30 herds were collected per rectum and subjected to the modified Baermann test. The overall prevalence of infection was 57.7%, significantly higher in goats (95.6%) than in sheep (20.7%) (p < 0.001). According to the binary logistic regression model, sheep dewormed with albendazole, mebendazole plus closantel, or ivermectin plus clorsulon presented a risk of Protostrongylidae infection 29.702, 7.426, or 8.720 times higher, respectively, than those dewormed with eprinomectin. Additionally, the presence of gastrointestinal parasites was investigated in 307 fecal samples using Mini-FLOTAC (R). The overall prevalence of infection was 86.3%, also significantly higher in goats (93.2%) than in sheep (79.9%) (p < 0.001). Strongyle-type eggs were the most frequently identified, both in sheep (69.8%) and goats (87.8%), followed by Eimeria oocysts (40.3% in sheep and 68.9% in goats). Considering the high prevalence and the burden of lungworm parasitic infection, it is urgent to determine its economic impact and the repercussions in animal health in the Centre region of Portugal to establish appropriate therapeutic guidelines.