The role of a cotton-lavender (Santolina chamaecyparissus L.) extract in female rats’ mammary cancer: from the chemoprevention effects to its genetic study

• Autor(a) principal: Azevedo, Tiago Araújo
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10348/11942
• topic: Breast cancer; N-methyl-N-nitrosourea

Breast cancer is the most frequently diagnosed cancer in women and one of the leading causes of death worldwide. Santolina chamaecyparissus L. is a medicinal plant with several medicinal properties, including anticancer, anti-diabetes and anti-inflammatory. The aim of this study was to evaluate the chemopreventive effect of S. chamaecyparissus aqueous extract (SCE) on breast cancer in female mice induced by N-methyl-Nnitrosourea (MNU). 28 four-week-old female Wistar rats were divided into four groups: control, MNUinduced (IND), SCE-supplemented (SCE), and SCE+IND. SCE was added to water (120 µg/mL) ad libitum. At 50 days of age, MNU was administered by intraperitoneal route. Weekly assessments of body mass, food and drink consumption, humane endpoints, and body temperature were done. Animals were palpated twice weekly to identify the appearance of mammary tumours. Other parameters were assessed, namely serum glucose and urine and faeces analysis. Twenty weeks after MNU administration, the animals were sacrificed by anaesthetic overdose, followed by exsanguination by cardiac puncture. A complete necropsy was performed, and samples of various tissues were collected for histological characterisation. Additionally, blood samples were used to determine blood count and serum biochemistry, while kidney and liver samples were used for oxidative stress analyses. Tumour samples were collected for gene expression studies. The chemical composition of the SCE was performed using LC-MS, with nineteen phenolic compounds, the most abundant molecules being myricetin-O-glucuronide and 1,3-O-dicaffeoylquinic acid. Two animals of the IND group were sacrificed before the end of the experimental protocol, because they exceeded the critical limit established for the humane endpoints. Supplementation with SCE delayed the development of mammary tumours, with the first mammary tumour being identified in the SCE+IND group six weeks after the first one was observed in the IND group. The mean volume and mean mass of tumours were slightly reduced in this group. The following haematological parameters exhibited significant differences between groups: total protein, haemoglobin, mean platelet volume, platelet distribution width, and neutrophil-lymphocyte ratio. With the exception of creatinine kinase, there were no differences in serum biochemistry parameters between groups. Evaluation of superoxide dismutase and catalase enzyme activity indicated no differences between groups. Gene expression of tumour markers revealed that relative levels of vascular endothelial growth factor expression were significantly reduced in tumours in the SCE+IND group. The levels of proliferating cell nuclear antigen and oestrogen receptor (ER)-α were slightly reduced in the tumours of the SCE+IND group; the expression of ER-β was slightly increased in the SCE+IND group. With neither detrimental effects on morphometric parameters with SCE supplementation, nor any influence on liver or kidney function or animal welfare, the tumour data obtained suggest that it could be a potential therapeutic option for breast cancer. Further studies, such as immunohistochemistry, will expand our understanding of the application of SCE as a chemopreventive agent in breast cancer.