Percorrer por autor "Medeiros, Catarina"
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- 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.
- Efeito da aplicação repetida de Cytinus hypocistis em murganhos transgénicos (K14HPV16): avaliação de humane endpointsPublication . Medeiros-Fonseca, Beatriz; Segurado, Olga; Costa, Diana; Medeiros, Catarina; Medeiros, Rui; Pires, Maria João; Bastos, Margarida M.S.M.; Silva, Ana Rita; Barros, Lillian; Ferreira, Isabel C.F.R.; Costa, Rui Miguel Gil; Oliveira, Paula A.Em, 1959 Russel e Burch propuseram os 3Rs (Reduce, Refine e Replacement) em experimentação animal e desde então as diversas entidades envolvidas na temática têm feito esforços conjuntos para os aplicar (1). Nesse sentido foi gradualmente introduzida a avaliação e registo dos humane endpoints (HE) dos animais durante procedimentos experimentais, para monitorizar o seu sofrimento e tomar decisões sobre a necessidade, ou não, de finalizar o ensaio antes da data prevista (2). Contudo, apesar das exigências legais, observa-se grande escassez de publicações sobre a avaliação de HE nos procedimentos com animais de laboratório. Assim, é nosso objetivo com este trabalho apresentar os HE durante a aplicação diária de um creme com Cytinus hypocistis numa estirpe de murganhos transgénicos.
- Effects of Ladder-Climbing Exercise on Mammary Cancer: Data from a Chemically Induced Rat ModelPublication . Silva, Jessica; Azevedo, Tiago; Aires, Inês; Medeiros, Catarina; Neuparth, Maria J.; Seixas, Fernanda; Ferreira, Rita; Faustino-Rocha, Ana I.; Oliveira, Paula A.; Duarte, José AlbertoBreast cancer remains a significant global health issue, affecting both humans and companion animals, particularly female dogs and cats, where mammary tumors are among the most common cancers. Strategies to minimize the impact of this disease on patients, pet owners, and veterinary medicine are essential. This study analyses the effects of resistance training on the development of chemically induced mammary cancer in female Wistar rats, divided into four groups: sedentary control (CTR), sedentary induced (CTR+N-methyl-N-nitrosourea (MNU)), exercised control (EX), and exercised induced (EX+MNU). The exercise protocol involved ladder climbing three times a week for 18 weeks with the load progressively increasing. At the study’s end, blood and histopathological samples were collected and analyzed. Although tumor onset occurred two weeks earlier and incidence was slightly higher in the exercised group (EX+MNU) compared to the control group (CTR+MNU), the mortality rate was lower, and the malignancy was not as aggressive. No systemic inflammation was observed, as the levels of albumin, C-reactive protein (CRP), and interleukin 6 (IL-6) in the MNU groups remained similar to the controls. Exercise has been shown to promote overall health by increasing physical fitness, boosting immunological function, and improving metabolic health. These findings may offer valuable insights into the potential role of resistance training in managing mammary cancer in companion animals. However, further research is required to assess clinical applicability and to establish safe and effective exercise protocols for veterinary oncology.
- Exploring the Chemopreventive and Antioxidant Effects of Spearmint Leaf Hydroethanolic Extract in HPV16-transgenic MicePublication . Jesus, Tiago M.; Azevedo, Tiago; Silva-Reis, Rita; Ferreira, Tiago; Nascimento-Gonçalves, Elisabete; Medeiros, Catarina; Ferreira, João; Gama, Adelina; Gaivão, Isabel; Pires, Maria João; Lanzarin, Germano; Félix, Luís; Venância, Carlos; Medeiros, Rui; Bastos, Margarida M.S.M.; Finimundy, Tiane C.; Barros, Lillian; Costa, Rui M. Gil da; Oliveira, Paula A.Human papillomavirus (HPV) is the most common sexually transmitted infectious agent and, in cases of persistent infection, may cause cancer. This study evaluated the toxicological and antitumor properties of Mentha spicata extract (MSE) in KP14HPV16 mice, which carry HPV16 oncogenes. Thirty‑three female FVB/n mice (Mus musculus), including 17 HPV‑transgenic and 16 wild‑type (WT) mice, were divided into six groups. The control groups received tap water (WT‑C, n=5, and HPV‑C, n=6), while the treatment groups received either 0.50 mg/ml MSE (WT‑50 and HPV‑50, n=6) or 0.55 mg/ml MSE (WT‑55 and HPV‑55, n=5) in drinking water for 28 days. Afterwards, animals were sacrificed, and blood and organs were collected for histopathological and biochemical analysis. The main phenolic compounds in MSE were rosmarinic acid and luteolin‑O‑glucoronide. MSE did not significantly affect weight gain in WT mice; however, WT‑55 gained significantly more weight than HPV‑55. MSE demonstrated antioxidant activity as indicated by the modulation of hepatic superoxide dismutase and glutathione S‑transferase (GST) activity, as well as renal GST activity, in MSE‑treated HPV groups. MSE did not reduce histological lesion incidence or systemic inflammation in HPV16‑transgenic mice. In general, while MSE was safe and exhibited antioxidant activity, it did not significantly impact HPV16‑induced lesions, warranting further research to assess systemic effects with different concentrations and durations.
- Morphometric measurements in HPV-transgenic mice after topical application of Cytinus hypocistis (L.) extractPublication . Silva, Ana Rita; Medeiros, Catarina; Ferreira, Teresa; Barros, Lillian; Ferreira, Isabel C.F.R.; Pires, Maria João; Costa, Rui Miguel Gil; Gama, Ana; Oliveira, Paula A.Human papillomavirus (HPV) infections are associated with the development of several anogenital cancers. K14HPV16 transgenic model is an animal model that mimics HPV-induced lesions. Cytinus hypocistis (L.) is an endophytic parasitic plant that has been shown to possess several antibacterial and antiproliferative properties1. During antiproliferative studies in animal models, the toxicological analysis is also required. Therefore, the present research aims to study the toxic effects of applying a topical formulation enriched with Cytinus hypocistis extracts (FCH) on K14HPV16 mice. Three different concentrations of FCH were used to enrich a base cream, the phenolic compounds were analyzed by HPLC-DAD-ESI/MS and were applied to the animal’s ears for 28 days. Thirty female mice were equally divided into six groups (G) (n=5): G1 (HPV16+-C1); G2 (HPV16+-C2); G3 (HPV16+-C3); G4 (HPVC3); G5 (HPV+-control); and G6 (HPV-control). The animals were kept under controlled conditions and biological variables were registered throughout the study. In the end, animals were sacrificed, and the organs collected and weighed. The main phenolic compound present in the base cream enriched with C. hypocistis was galloyl-bis-HHDPglucose. Food and water intake were constant throughout the trial. G3 presented a higher relative weight of the liver and lungs than the control animals, and a significant difference in body weight relatively to G4 (p<0.05). The body weight loss and the increase in liver weight observed in HPV+ mice treated with they may reflect a negative impact of the extract on these already fragile animals. However, overall, the FCH was well tolerated by the animals. Although the highest concentration of the extract had a negative impact on the evaluated morphometric parameters, this does not necessarily imply that the extract is toxic, which can be corroborated with histological analysis. Further studies are needed to understand whether different doses of this extract would cause distinct effects.