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Potencial epigenético do Pterocarpano em combinação com Vorinostat: da modelagem computacional à biologia celular em câncer hematológico e de próstata

2026-05-25T14:34:26Z

Título: Potencial epigenético do Pterocarpano em combinação com Vorinostat: da modelagem computacional à biologia celular em câncer hematológico e de próstata Autor(es): Sousa, Eduardo de Moraes e Abstract: Introduction: Epigenetic alterations allow gene expression to be modulated without changing the DNA sequence. Epigenetics has advanced as a promising area in cancer treatment. Epigenetic drugs, or simply epidrugs, act on key enzymes, reactivating epigenetically silenced genes involved in tumor suppression and DNArepair. Inthe context ofcancertherapy, naturally occurring compounds such as flavonoids, isoflavonoids, and pterocarpan stand out for their pro apoptotic, antiproliferative, and regulatory properties of epigenetic targets, such as DNMTs, HDACs and HATs. Given the need to develop new approaches that overcome the limitations of monotherapy, the combination of pterocarpane (+)-PTC with the HDAC inhibitor Vorinostat (SAHA) emerges as an alternative strategy for cancer treatment. The main objective of this thesis was to investigate the epigenetic potential of (+)-PTC pterocarpane and its combination with the HDAC inhibitor Vorinostat (SAHA) in the treatment of hematological and prostate tumors. Methodology: In silico and in vitro approaches were applied in a complementary manner. ADME profiling and molecular docking tools allowed us to predict interactions between compounds and epigenetic targets, guiding in vitro assays with greater precision and economy. This thesis is structured in two chapters: the first includes a literature review of flavonoids, isoflavonoids, and pterocarpans with epigenetic activity against different types of cancer and a prediction of their pharmacokinetic properties; the second presents molecular docking interaction assays, evaluation of the synergistic potential of the combination ((+) PTC+SAHA), and cytotoxicity of (+)-PTC and SAHA on cell viability and cell cycle progression in cancer cell lines. Results: The first chapter highlights the potential of flavonoids, isoflavonoids, and pterocarpans in epigenetic modulation and other molecular pathways, such as p19Arf-p53-p21Cip1, PI3K/AKT/mTOR, and TRPM3/miR-204, inhibiting cell proliferation, restoring homeostasis, and reprogramming gene expression, which makes these compounds promising candidates in oncological research. The SwissADME BOILED-Egg model highlighted the (+)-PTC molecule with good gastrointestinal (GI) absorption and blood brain barrier (BBB) penetration capacity, in addition to indicating it as a likely substrate of Pgp glycoprotein, all valuable characteristics for a drug candidate for oncohematological treatments. The second chapter highlights the therapeutic potential of the ((+)-PTC+SAHA) combination, given its enhanced antitumor response and indication of synergism between the compounds. The molecular docking results indicated that the chosen ligands showed attraction to the site of interest in most of the selected poses, with emphasis on HDACs 1 and 2, and HSP90, whose results were above 90% attraction for both ligands (control and (+)-PTC). It should be noted that (+)-PTC tends to bind spontaneously as much as the control ligands, as observed by the very close difference between ΔG values (-0.549 kcal/mol for HDAC8 and 1.874 kcal/mol for HDAC3- site I0P). However, the stability of the binding of most control ligands is more robust than that of (+)-PTC. Even though the reactions between HDACs and (+)-PTC are favorable, the latter tends to form more stable complexes with the HSP90 protein. Thesimulation of potential synergistic effects in CompuSyn suggested concentrations that were unfeasible for practical effect for 24h and 48h (respectively, Fa = 0.5 (+)-PTC 8.466 µM and SAHA 66.659 µM; Fa = 0.5 (+)-PTC 5.226 µM and SAHA 78.556 µM). Morphological changes were observed in the MOLM-13 and KG-1 cell lines caused by exposure to (+)-PTC and SAHA compounds, either separately or in combination. For cells of the MOLM-13 line treated with the compound (+)-PTC, morphological changes such as cytoplasmic bleb formation, plasma membrane rupture, pyknosis, and karyolysis were observed, while in the groups treated with the compound Vorinostat, membrane rupture and the presence of vacuoles were identified in a more noticeable way. For KG-1 cells treated with the combination ((+) PTC+SAHA), more marked morphological changes for apoptosis were observed, such as vacuolization, pyknosis, and karyolysis. Conclusion: Despite methodological limitations, the combination ((+)-PTC+SAHA) showed promising effects against leukemia cell lines. These results predict a reduction in adverse effects compared to monotherapies and suggest new avenues for epigenetic therapeutic strategies. Although further studies covering gene and protein expression analyses, systemic toxicity assessment, and in vivo experiments are still needed, this study demonstrated that the integration of in silico and in vitro approaches is an essential element for research progress and the discovery of new ways to fight cancer. Tipo: Tese

Efeitos do α-pineno livre ou encapsulado em lipossomas durante o cultivo de folículos pré-antrais e maturação oocitária em bovinos

2025-12-16T20:30:39Z

Título: Efeitos do α-pineno livre ou encapsulado em lipossomas durante o cultivo de folículos pré-antrais e maturação oocitária em bovinos Autor(es): Azevedo, Venância Antonia Nunes Abstract: Growing evidence has demonstrated that oxidative stress compromises in vitro culture (IVC) of ovarian follicles and in vitro maturation (IVM) of oocytes. Thus, strategies to reduce oxidative stress are essential to improve the quality of cultured follicles and oocytes. The objectives of this study were: 1) to investigate the effects of α-pinene during IVC of pre-antral follicles in bovine ovarian tissue; 2) to develop and characterize liposomes loaded with α-pinene and analyze their cytotoxicity in bovine cumulus cells (CCs) and evaluate their effects during IVM of bovine oocytes and subsequent parthenogenetic embryonic development. In Phase 1, ovarian tissue fragments were cultured for 6 days in α-MEM+ (control) or supplemented with 1.25, 2.5, 5, 10, or 20 µg/mL of α-pinene. In Phase 2, liposomes loaded with α-pinene (Lip-α-pinene) were produced using the lipid film hydration technique, characterized, and evaluated Regarding cytotoxicity in bovine cumulus oocyte complexes (COCs), cumulus oocyte complexes (COCs) were subsequently matured for 22-24 hours in maturation medium (control) or supplemented with Lip-white (empty liposome) or Lip-α-pinene at concentrations of 0.01, 1, or 100 µg/mL. After IVM, only mature oocytes proceeded to parthenogenetic activation and embryo culture. Data were analyzed using chi-square, Student's t-test, Kruskal-Wallis test, and ANOVA followed by Tukey's test (GraphPad Prism 9.0), with a significance level set at P < 0.05. In Phase 1, α-pinene at concentrations of 2.5, 5, or 10 µg/mL increased the percentage of normal follicles (P > 0.05) compared to the control, without influencing follicular growth (P < 0.05). α-pinene (10 µg/mL) maintained stromal cell density and collagen levels in cultured ovarian tissue similar to non-cultured tissues (P > 0.05) and increased mRNA levels for NRF2 and PRDX6 (P < 0.05) compared to the control. In Phase 2, Lip-α-pinene presented a size of 75.86 ± 0.95 nm, low polydispersity (0.26 ± 0.00), zeta potential of -31.55 ± 2.23 mV, encapsulation efficiency of 85 ± 2.51%, and Lip-α-pinene was not cytotoxic to CCs (P > 0.05). Lip-α-pinene did not affect the nuclear maturation rate (P > 0.05); however, 1 µg/mL of Lip-α-pinene preserved the ultrastructure of CCs and the oocyte, reduced ROS and lipid accumulation compared to the control, Lip-blank, and 100 µg/mL of Lip-α-pinene (P < 0.05). This result was accompanied by an increase in NRF2, SOD, and PRDX6 levels (P < 0.05). Furthermore, 1 and 100 µg/mL Lip-α-pinene increased cleavage rates and the number of cells per blastocyst (P < 0.05), but did not affect blastocyst formation and lipid content (P > 0.05). In conclusion, α-pinene preserves follicular structure, tissue integrity, and modulates antioxidant genes during ovarian tissue culture. When encapsulated, α-pinene increases the antioxidant capacity of oocytes by reducing ROS and increasing NRF2, SOD, and PRDX6 levels, improving the quality of oocytes and parthenogenetic embryos. Tipo: Tese

Efeitos protetores in vitro e in vivo da aloe vera contra danos ovarianos induzidos por Doxorrubicina em camundongos fêmeas

2025-11-27T16:34:06Z

Título: Efeitos protetores in vitro e in vivo da aloe vera contra danos ovarianos induzidos por Doxorrubicina em camundongos fêmeas Autor(es): Assis, Ernando Igo Teixeira de Abstract: Doxorubicin (DOX) is used to treat several types of cancer, but it causes ovarian toxicity by increasing the formation of reactive oxygen species (ROS), causing oxidative stress and an exacerbated inflammatory response. Thus, the use of natural compounds with antioxidant and anti-inflammatory properties against the toxic side effects induced by antineoplastic drugs has been highlighted. This study aimed to investigate the action of Aloe vera extract against the deleterious effects of DOX on follicular survival and growth in female mice. For this purpose, female Swiss mice with a regular estrous cycle in phases 1 and 2 were used. For phase 1 the animals (n = 37) had their ovaries collected and cultured individually in a 24-well plate at 37.5° C, in 5% CO2, for 6 days. The ovaries were cultured in DMEM+ alone; in medium supplemented with DOX (0.3 μg/mL); or in this case in DMEM+ supplemented with DOX (0.3 μg/mL) combined with Aloe vera (5%, 10%, 25% or 50%). After culture, the ovaries were collected and fixed for analysis. In phase 2, the animals (n = 48) were divided into six groups (8 per group): positive control (NAC+DOX), which received pretreatment with N-acetylcysteine orally (PO) and, 1 hour later, a single intraperitoneal (IP) dose of DOX; negative control (SAL+DOX), with PO pretreatment with saline followed, 1 hour later, by DOX (IP); three groups pretreated with Aloe vera extract (0.1, 1.0 or 10.0 mg/kg, PO) and, 1 hour later, subjected to a dose of DOX (IP) (AV0.1+DOX, AV1.0+DOX and AV10.0+DOX); and control (SAL+SAL), which received saline solution by PO and IP. DOX was administered in a single dose and Aloe vera was administered on three consecutive days; 24 hours after the last application (on the fourth day), the ovaries were collected, thus, the experiment lasted four days. The ovaries collected in phases 1 and 2 were intended for histological analysis (morphology, growth, activation, extracellular matrix (ECM) configuration and stromal density), immunohistochemistry (TNF-α) and evaluation of mRNA levels for superoxide dismutase (SOD), catalase (CAT), nuclear factor-erythroid 2-related factor 2 (NRF2) and tumor necrosis factor-α (TNF-α) by real-time PCR. Statistical analysis was performed using GraphPad Prism and differences were considered significant when P < 0.05. Phase 1 results showed that ovaries cultured with DOX alone showed a reduction in the percentage of normal follicles and in the density of stromal cells. However, the addition of Aloe vera extract to the medium not only attenuated these structural damages but also increased collagen deposition. Furthermore, ovaries cultured with DOX and Aloe vera (10 and 25%) showed a reduction in TNF-α immunostaining and an increase in mRNA expression for antioxidant enzymes (SOD, CAT and NRF2). The results of phase 2 showed that 0.1 and 1.0 mg/kg of Aloe vera preserved both ovarian follicles and stromal density against DOX-induced damage. In addition, 0.1 and 1.0 mg/kg of Aloe vera reduced TNF-α immunostaining and increased the percentage of collagen fibers. Furthermore, the 1.0 mg/kg dose of Aloe vera increased the mRNA expression for antioxidant enzymes (SOD, CAT and NRF2), while 0.1 mg/kg of Aloe vera maintained these expression levels similar to the saline group. In conclusion, the results obtained indicate that Aloe vera extract, both in vitro and in vivo, demonstrated a protective effect on the ovaries of female mice against damage induced by DOX. This effect was evidenced by increased antioxidant response, reduced inflammation, preservation of the stroma and maintenance of follicular morphology. Tipo: Tese

Remodelação do córtex ovariano durante o cultivo in vitro e efeitos de bioandaimes descelularizados e nanopartículas poliméricas carregadas com resveratrol no crescimento e viabilidade de folículos secundários bovinos.

2025-10-13T20:53:15Z

Título: Remodelação do córtex ovariano durante o cultivo in vitro e efeitos de bioandaimes descelularizados e nanopartículas poliméricas carregadas com resveratrol no crescimento e viabilidade de folículos secundários bovinos. Autor(es): Costa, Francisco das Chagas Tipo: Tese