Browsing by Author "Faustino-Rocha, A. I."
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- Animal Models in Phytopharmacology and Toxicological Testing of Plant ProductsPublication . Faustino-Rocha, A. I.; Medeiros-Fonseca, B; Vala, Helena; Pires, Maria J.; Vasconcelos-Nóbrega, C.; Oliveira, Paula A.; Corresponding author: Faustino-Rocha, A. I..Plant products have been used worldwide for thousands of years in traditional medicine for their potential health benefits. Nowadays, plant products still play an important role in healthcare, especially in developing countries where the access to basic medicines and health facilities is inadequate. Although the plant products are presumed safe and there is a conviction that “It is natural, then it is harmless”, some of them have been associated with acute or chronic intoxications. The toxic effects include allergic reactions; carcinogenic action; cardiovascular, hematological, and neurological difficulties; gastrointestinal symptoms; renal or hepatic toxicity; and, in most severe cases, the death. Once safety is a major concern with the plant products to be used in animals or humans, it is important to conduct toxicity studies on them to ascertain their safety. Animals have been long used to study several diseases, and they are an invaluable tool to test the safety of plant products. This chapter aimed to offer a review concerning the animal models available for phytopharmacology and toxicological testing of plant products.
- Expression of estrogen receptors-α and β in chemically-induced mammary tumoursPublication . Faustino-Rocha, A. I.; Gama, A.; Oliveira, P. A.; Alvarado, A.; Vala, Helena; Ferreira, R.; Ginja, M.Objective: Estrogen receptors (ERs)-α and β are important for stimulating the growth and differentiation of human mammary tumours, respectively. This work aimed to evaluate the expression of ERs-α and β in rat chemically-induced mammary tumours. Methods: Procedures followed the European legislation (2010/63/EU). Fifteen seven-week-old female Sprague-Dawley rats received an intraperitoneal injection of N-methyl-N-nitrosourea (MNU) (50mg/Kg). At sacrifice, mammary tumours were fixed and histologically evaluated. Sections were incubated with ER-α and β primary antibodies and the percentage of immunopositive cells was determined. Results: During the experimental protocol four animals died, all survived animals developed mammary tumours: 30 benign, 2 preneoplastic and 39 malignant lesions. All histological patterns expressed ERs-α and β. The mean expression of ER-α (55.14% ± 13.26) was lower than the expression of ER-β (70.06% ± 18.51) (p<0.05). The expression of both receptors was not statistically different among lesions, however it was higher in preneoplastic lesions, followed by malignant and benign ones (p>0.05). Conclusion: All MNU-induced mammary tumours in rats expressed ERs-α and β, being a good model of ER-positive human mammary tumours. Once the expression of ER-β was higher, tumours’ differentiation was stimulated and its proliferation was inhibited.