Browsing by Author "Oliveira, Paula A."
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- Aloysia citrodora extract as a chemopreventive agent against HPV16-induced lesions: findings from K14-HPV16 micePublication . Medeiros-Fonseca, Beatriz; Faustino-Rocha, Ana I.; Silva, Jéssica; Silva, Mónica G.; Pires, Maria João; Neuparth, Maria João; Vala, Helena; C, Vasconcelos-Nóbrega; Dias, Maria I.; Barros, Lillian; Gonçalves, Lio; Gaivão, Isabel; Bastos, Margarida M. S. M.; Félix, Luís; Venâncio, Carlos; Medeiro, Rui; Costa, Rui M. Gil da; Oliveira, Paula A.Aim: 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.
- 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.
- Exploring the therapeutic potential of Quercus ilex acorn extract in papillomavirus-induced lesionsPublication . Medeiros-Fonseca, Beatriz; Faustino-Rocha, Ana I.; Pires, Maria João; Neuparth, Maria João; Vala, Helena; Nóbrega, Carmen; Gouvinhas, Irene; Barros, Ana Novo; Dias, Maria Inês; Barros, Lillian; Bastos, Margarida M. S. M.; Gonçalves, Lio; Félix, Luís; Venâncio, Carlos; Medeiros, Rui; Costa, Rui Miguel Gil da; Oliveira, Paula A.Background and Aim: Papillomaviruses (PVs) infections have been documented in numerous animal species across different regions worldwide. They often exert significant impacts on animal health and livestock production. Scientists have studied natural products for over half a century due to their diverse chemical composition, acknowledging their value in fighting cancer. Acorns (Quercus ilex) are believed to have several unexplored pharmacological properties. This study aimed to evaluate the in vivo safety and cancer chemopreventive activity of an infusion extract of Q. ilex in a transgenic mouse model of human PV (HPV)-16, which developed squamous cell carcinomas through a multistep process driven by HPV16 oncogenes. Materials and Methods: Q. ilex extract was prepared by heating in water at 90°C and then characterized by mass spectrometry. Phenolic compounds from this extract were administered in drinking water to female mice in three different concentrations (0.03, 0.06, and 0.09 g/mL) over a period of 28 consecutive days. Six groups (n = 6) were formed for this study: group 1 (G1, wildtype [WT], water), group 2 (G2, HPV, water), group 3 (G3, WT, 0.09 g/mL), group 4 (G4, HPV, 0.03 g/mL), group 5 (G5, HPV, 0.06 g/ mL), and group 6 (G6, HPV, 0.09 g/mL). Throughout the experiment, humane endpoints, body weight, food intake, and water consumption were recorded weekly. Following the experimental period, all mice were sacrificed, and blood, internal organs, and skin samples were collected. Blood was used to measure glucose and microhematocrit and later biochemical parameters, such as creatinine, urea, albumin, alanine aminotransferase, and total proteins. Histological analysis was performed on skin and organ samples. Results: The administration of Q. ilex extract resulted in a statistically significant increase in relative organ weight among HPV transgenic animals, indicating adaptive biological response to the tested concentrations. Moreover, a reduction in characteristic skin lesions was observed in animals treated with the 0.06 and 0.09 g/mL extract. Conclusion: These results provide a favorable chemopreventive profile for Q. ilex extract at concentrations of 0.06 and 0.09 g/mL. This study highlights the potential of Q. ilex extract as a safe and effective therapeutic strategy against HPV16- associated lesions in transgenic mouse models. The limitation of our study was the durability of transgenic animals. As a more sensitive species, we must always be careful with the durability of the test. We intend to study concentrations of 0.06 and 0.09 g/mL for longer to further investigate their possible effects.
- Histopathological features of organs in a rat model of mamamry carcinogenesis: a reference databasePublication . Vala, Helena; Nóbrega, Carmen; Gama, Adelina; Ferreira, Rita; Oliveira, Paula A.; Faustino-Rocha, Ana I.Mammary tumors’ development was induced through the intraperioneal administration of the carcinogen N-methyl-N-nitrosourea (MNU). Animals from group control were injected with the vehicle (saline solution). Animals were sacrificed at 25 weeks-old and the organs were histopathologically evaluated. A higher number of lesions was observed in the organs of animals from group MNU. The animals from group control did not present any lesion in lymph nodes. Independently of the experimental group, the internal organs presented hemodynamic alterations, degenerative and inflammatory changes. Hemodynamic changes may be consequence of euthanasia method. As expected, the higher number and the higher grade of the lesions in group MNU were due to the carcinogen administration.
- Study on the antineoplastic and toxicological effects of pomegranate (Punica granatum L.) leaf infusion using the K14-HPV16 transgenic mouse modelPublication . Yu, Manyou; Gouvinhas, Irene; Pires, Maria J.; Neuparth, Maria J.; Costa, Rui M. Gil da; Medeiros, Rui; Bastos, Margarida M.S.M.; Vala, Helena; Félix, Luis; Venancio, Carlos; Barros, Ana I: R. N. A.; Oliveira, Paula A.Punica granatum L. (pomegranate) has been used in functional foods due to its various health benefits. However, the in vivo biological potential of its leaf remains little known. This study has aimed to characterize the antineoplastic and toxicological properties of using pomegranate leaf infusion (PLI) on transgenic mice carrying human papillomavirus (HPV) type 16 oncogenes. Thirty-eight mice were divided into 3 wild-type (WT) and 3 transgenic (HPV) groups, with exposure to 0.5% PLI, 1.0% PLI, and water. The animals' body weight, drink and food consumption were recorded. Internal organs, skin samples and intracardiac blood were collected to evaluate toxicological parameters, neoplastic lesions and oxidative stress. The results indicated that PLI was safe as no mortality, no behavioural disorders and no significant differences in the levels of microhematocrit, serum biochemical markers, internal organ histology, and oxidative stress was found among the WT groups. Histological analysis revealed that HPV animals that consumed PLI exhibited reduced hepatic, renal and cutaneous lesions compared with the HPV control group. Low-dose PLI consumption significantly diminished renal hydronephrosis lesions and relieved dysplasia and carcinoma lesions in the chest skin. Oxidative stress analysis showed that low-dose PLI consumption may have more benefits than high-dose PLI. These results suggest that oral administration of PLI has the potential to alleviate non-neoplastic and neoplastic lesions against HPV16-induced organ and skin injuries, though this requires further scientific research studies.
- Virtual Physiology: A Tool for the 21st CenturyPublication . Nóbrega, Carmen; Aires Pereira, Maria; Coelho, Catarina; Brás, Isabel; Mega, Cristina; Santos, Carla; Esteves, Fernando; Cruz, Rita; Faustino-Rocha, Ana I.; Oliveira, Paula A.; Mesquita, João; Vala, HelenaVeterinary physiology is a basic curricular unit for every course within the veterinary field. It is mandatory to understand how the animal body works, and what to expect of a healthy body, in order to recognize any misfunction, and to be able to treat it. Classic physiology teaching involves wet labs, much equipment, many reagents, some animals, and a lot of time. But times are changing. In the 21st century, it is expected that the teaching and learning process can be more active and attractive, motivating students to learn better. It is necessary to understand what students like, and to introduce novelties into the school routine. The use of a game-based learning, using “new” technologies, creating virtual experiences and labs, reducing the costs of reagents, equipment, and especially reducing the use of animals, will be the future for physiology teaching.