Browsing by Author "Azevedo, Tiago"
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- 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.
- Supplementation of an anthocyanin-rich elderberry (Sambucus nigra L.) extract in FVB/n mice: a healthier alternative to synthetic colorantsPublication . Azevedo, Tiago; Ferreira, Tiago; Ferreira, João Miguel Mendes; Teixeira, Filipa; Ferreira, Diana; Silva-Reis, Rita; Neuparth, Maria João; Pires, Maria João; Pinto, Maria de Lurdes; Costa, Rui Miguel Gil; Bastos, Margarida M.S.M.; Medeiros, Rui; Felix, Luis; Venâncio, Carlos; Dias, Maria Inês; Gaivão, Isabel; Barros, Lillian; Oliveira, Paula A.Featured Application Due to anthocyanins' potential as colorants, this anthocyanin-rich elderberry extract presents a healthier alternative to commercially available colorants and has the potential to be used at industry level. Sambucus nigra L., popularly known as elderberry, is renowned for its amazing therapeutic properties, as well as its uses as a food source, in nutraceuticals, and in traditional medicine. This study's aim was to investigate the effects of an elderberry extract (EE) on mice for 29 days, as well as the safety of the extract when used as a natural colorant. Twenty-four FVB/n female mice (n = 6) were randomly assigned to one of four groups: control, 12 mg/mL EE (EE12), 24 mg/mL EE (EE24), or 48 mg/mL EE (EE48). The predominant anthocyanins detected were cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside. Food and drink intake were similar between groups, with the exception of EE48, who drank significantly less compared with the Control. Biochemical analysis of the liver showed that the changes observed in histological analysis had no pathological significance. The EE, at doses of 24 and 48 mg/mL, significantly reduced the oxidative DNA damage compared with the non-supplemented group. The S. nigra extract showed a favorable toxicological profile, affording it potential to be used in the food industry.
- The role of natural compounds in rat mammary cancer: the beneficial effects of Santolina chamaecyparissus L. aqueous extractPublication . Azevedo, Tiago; Silva, Jessica; Peixoto, Francisco P.; Silvestre-Ferreira, Ana C.; Gama, Adelina; Seixas, Fernanda; Finimundy, Tiane C.; Barros, Lillian; Matos, Manuela; Oliveira, Paula A.; Faustino-Rocha, Ana; Valada, Abigaël; Anjos, Lara; Moura, Tânia; Ferreira, Rafaela; Santos, Marlene; Pires, Maria João; Neuparth, Maria JoãoBreast cancer is the most diagnosed cancer among women, and a leading cause of death worldwide. Santolina chamaecyparissus L. is a plant with multiple health benefits, including anticancer and anti-diabetic properties. This study aimed to assess the chemopreventive effects of S. chamaecyparissus aqueous extract (SCE) in an animal model of mammary cancer. A total of 28 four-week-old female Wistar rats were divided into four groups: control, MNU-induced (IND), SCE-supplemented (SCE), and SCE+IND. SCE was added to drinking water (12.72 mg/kg body weight) ad libitum. MNU was administered via the intraperitoneal route at 50 days of age. Weekly monitoring of body weight, food/drink intake, humane endpoints, and number of mammary tumours were recorded. Twenty weeks after MNU administration, animals were sacrificed by anaesthetic overdose and a necropsy was performed. Blood samples were used to determine blood count and serum biochemistry analysis, while kidney and liver samples were analysed for oxidative stress. Tumour samples were collected for gene expression and histology studies. SCE chemical composition was analysed by LC-MS and contained 19 phenolic compounds, with the most abundant being myricetin-O-glucuronide and 1,3-O-dicaffeoylquinic acid. Two animals in the IND group were sacrificed due to exceeding the humane endpoint limits. SCE supplementation delayed mammary tumour development, reducing its volume and weight. SCE had a positive impact on haematological parameters, particularly the neutrophil-lymphocyte ratio (P=0.026). No significant differences were observed in serum biochemistry, except for creatinine kinase MB, or in oxidative stress markers. Gene expression analysis showed significantly reduced VEGF expression levels (P=0.0158) in tumours from SCE+IND. These findings suggest that SCE is deserving of further study to identify the individual compounds and to understand its influence on animal models during cancer development.