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Interplay Between Western Diet and Mammary Cancer: Data from a Chemically-induced Model in Wistar Rats

Publication . Silva, Jessica; Azevedo, Tiago Araújo; Aires, Inês; Peixoto, Francisco P.; Neuparth, Maria João; Queiroga, Felisbina; Seixas, Fernanda; Ferreira, Rita; Faustino-Rocha, Ana; Duarte, José Alberto; Oliveira, Paula A.

This study aimed to investigate the influence of Western diet on mammary cancer in Wistar female rats, focusing on systemic responses and tumor development. Materials and Methods: Twenty-eight Wistar female rats were acclimatized and divided into four experimental groups (n=7 each): Western diet (WD), Western diet with N-methyl-N-nitrosourea (MNU) administration (WD+MNU), standard diet (CTR), and standard diet with MNU administration (CTR+MNU). MNU was administered intraperitoneally at 50 mg/kg at seven weeks of age to induce mammary cancer. The 20-week experiment involved monitoring animal weight, food and water intake. At the end of the study, rats were euthanized, and blood samples and organs were collected for hematological and plasma biochemical analysis, oxidative stress, and histo-pathological and immunobiological evaluations of the tumors. Results: No significant differences were found in body weight, composition, or organ weights, but the WD group showed reduced food and water intake and lower cholesterol levels. Leptin and adiponectin levels were higher in the WD+MNU group, suggestive of changes in appetite regulation. Histopathological analysis showed malignant tumors in both MNU-induced groups. However, WD groups had fewer tumors compared to the CTR+MNU group. Conclusion: WD led to higher feed efficiency and increased visceral adipose tissue but decreased systemic cholesterol and triglyceride levels. While this diet resulted in lower tumor incidence, the volume and weight of the tumors were higher. Additionally, the WD decreased ERα and progesterone receptor immunoexpression, while Ki-67 immunoexpression was elevated.

2024Journal article

Open access

Aloysia citrodora extract as a chemopreventive agent against HPV16-induced lesions: findings from K14-HPV16 mice

Publication . 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.

2024Journal article

Open access

Realistic Aspects of Cardiac Ultrasound in Rats: Practical Tips for Improved Examination

Publication . Silva, Jessica; Azevedo, Tiago Araújo; Ginja, Mário; Oliveira, Paula A.; Duarte, José Alberto; Faustino-Rocha, Ana

Echocardiography is a reliable and non-invasive method for assessing cardiac structure and function in both clinical and experimental settings, offering valuable insights into disease progression and treatment efficacy. The successful application of echocardiography in murine models of disease has enabled the evaluation of disease severity, drug testing, and continuous monitoring of cardiac function in these animals. However, there is insufficient standardization of echocardiographic measurements for smaller animals. This article aims to address this gap by providing a guide and practical tips for the appropriate acquisition and analysis of echocardiographic parameters in adult rats, which may also be applicable in other small rodents used for scientific purposes, like mice. With advancements in technology, such as ultrahigh-frequency ultrasonic transducers, echocardiography has become a highly sophisticated imaging modality, offering high temporal and spatial resolution imaging, thereby allowing for real-time monitoring of cardiac function throughout the lifespan of small animals. Moreover, it allows the assessment of cardiac complications associated with aging, cancer, diabetes, and obesity, as well as the monitoring of cardiotoxicity induced by therapeutic interventions in preclinical models, providing important information for translational research. Finally, this paper discusses the future directions of cardiac preclinical ultrasound, highlighting the need for continued standardization to advance research and improve clinical outcomes to facilitate early disease detection and the translation of findings into clinical practice.

2024Journal article

Open access