Assessment of methomyl-induced adrenal gland disruption in rat fetuses and pups: Potential protective effects of propolis supplementation.

The present study aimed to unravel the possible adverse effects of methomyl on the developing adrenal gland of rat fetuses and pups. Additionally, this study explored the potential improving effects of propolis against these possible hazards induced by methomyl exposure. To achieve that, pregnant rats were divided into four groups: control group, received 1 mL distilled water, propolis group, received 1 mL propolis at a dose of 300 mg/kg, methomyl group, received 1 mL methomyl at a dose of 2 mg/kg, and combined group, received 1 mL methomyl followed by 1 mL propolis, an hour later at the same previous doses. The results revealed that methomyl exposure, during pregnancy and lactation, induced many histological and ultrastructural changes, caused DNA damage and downregulated the expression of steroidogenic acute regulatory (StAR) and CYP11B2 genes in the adrenal glands of both rat fetuses and pups. Interestingly, propolis supplementation demonstrated a remarkable ability to mitigate these deleterious effects and restored the histology and ultrastructure architecture of the adrenal glands of both fetuses and pups, as well as decreased DNA damage and upregulated the expression of StAR and CYP11B2 genes in the adrenal gland of rat fetuses and pups. In conclusion, our study highlights the potential hazardous impact of methomyl exposure during pregnancy and lactation on the development of the adrenal gland in rat fetuses and pups, moreover, the study presents a new approach to alleviate these effects through propolis administration which could be used as a dietary supplement to mitigate the adverse effects of methomyl exposure.

Evaluating phase II results of Baxdrostat, an aldosterone synthase inhibitor for hypertension.

INTRODUCTION: Hypertension, a global health concern, poses a significant risk for other cardiovascular diseases. While lifestyle modifications and interventions like the Dietary Approaches to Stop Hypertension (DASH) diet offer some respite, their maintenance can be challenging. Recently, the spotlight has turned toward the renin-angiotensin-aldosterone system, a crucial player in the pathophysiology of hypertension. Contrary to other drugs, Baxdrostat, an innovative aldosterone synthase inhibitor (ASI), targets aldosterone synthesis, mitigating negative systemic effects. AREAS COVERED: Baxdrostat showcases rapid absorption, high oral bioavailability, and significant selectivity for aldosterone synthase which presents a proactive approach to hypertension management by reducing aldosterone levels. Early trials have demonstrated its potential in lowering blood pressure in resistant hypertension cases. Current clinical trials are also exploring its application in primary aldosteronism and chronic kidney disease, with preliminary findings indicating its promise as a novel antihypertensive agent. This article encapsulates the current state of knowledge regarding Baxdrostat, encompassing its uses, ongoing clinical trials, and potential future clinical applications. EXPERT OPINION: Future research endeavors will play a pivotal role in unveiling the effectiveness and safety profile of this novel medication. Thus, positioning the baxdrostat as a valuable addition to the armamentarium of antihypertensive agents, especially for patients with complex, multifactorial hypertensive conditions.

Effects of 20-hydroxyecdysone on UVB-induced photoaging in hairless mice.

We recently reported that exposure of skin to ultraviolet B (UVB) irradiation for 2 weeks induces stress and accelerates skin aging. Interestingly, aldosterone synthase is known to be crucial in generating UVB-induced stress-related responses, suggesting that drugs that regulate its activity can be used as skin antiaging agents. Through extensive drug screening, we have identified 20-hydroxyecdysone (20E), a steroidal prohormone secreted by the prothoracic glands of insects, as a potent inhibitor of UVB-induced aging. Although 20E has been shown to exert antistress and anti-collagenase effects in vitro, its effects in vivo remain unexplored. Furthermore, the pharmacological and physiological effects of 20E on UVB-mediated photoaging are poorly understood. Therefore, in this study, we investigated the effects of 20E on aldosterone synthase and UVB-induced photoaging and skin lesions in hairless mice, focusing on the stress-related hypothalamic-pituitary-adrenal axis. We confirmed that 20E inhibited aldosterone synthase and reduced corticosterone levels. When applied to a UV-induced skin aging animal model, it ameliorated UV-induced stress and protected against the decrease in collagen levels. Importantly, when the aldosterone synthase inhibitor osilodrostat, an FDA-approved drug, was applied to the UV-induced skin aging model, the stress-reducing and antiaging effects of 20E were not observed. Thus, we conclude that 20E inhibits UVB-induced skin aging by blocking aldosterone synthase and is a potential candidate to prevent skin aging.

Investigation of combined effects of propyl paraben and methyl paraben on the hypothalamic-pituitary-adrenal axis in male rats.

The aim of this study was to investigate the endocrine-disrupting effects of methyl paraben (MeP) and propyl paraben (PrP) mixture on the hypothalamic-pituitary-adrenal axis (HPA). In this study, six experimental groups were designated. These groups included three control groups (control, corn oil control, and positive control (50 mg/kg/day BPA)) and three dose groups (10, 100, and 500 mg/kg/day MeP+PrP). MeP with PrP were mixed in a 1:1 ratio and administered to the 42-day-old male rats by oral gavage for 30 days. At the end of the experiment, adrenocorticotropic hormone (ACTH), corticosterone and aldosterone hormones were analyzed in serum. Effects of MeP+PrP on the adrenal glands were investigated by immunohistochemical staining of 11ß hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) enzymes involved in the synthesis steps of corticosterone and aldosterone. Also, pituitary and adrenal glands were examined histopathologically. In the histopathological findings, cortical nodule, congestion, and edema were found in the tissues. In the pituitary gland, cytokeratin rings were detected in all MeP+PrP dose groups, supporting the increase of corticosterone and ACTH. Serum corticosterone, aldosterone, and ACTH hormone levels were increased in the 100 mg/kg/day MeP+PrP and BPA groups. Results obtained from immunohistochemical staining showed that increased staining parallelled increased corticosterone and aldosterone hormone levels. In summary, the results showed that exposure to the MeP+PrP mixture caused a significant increase in ACTH and corticosterone. Also, the MeP+PrP mixture caused a significant increase of CYP11B1 and CYP11B2. MeP+PrP exposure disrupts the normal HPA axis.

High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells.

(Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release.

Modelos celulares hepáticos para estudios de Hepatotoxicidad y Metabolismo de fármacos / Hepatic cellular models to investigate Hepatotoxicity and Metabolism of drugs

Aspectos clave en el desarrollo de todo nuevo fármaco son el conocimiento de las rutas metabólicas y la potencial toxicidad factores determinantes de su eficacia terapeútica y para la evaluación de su seguridad en su administración al hombre. Los modelos celulares hepáticos que se pueden utilizar para realizar in vitro estos estudios, se clasifican en tres grandes categorias: 1) cultivos primarios de hepatocitos, 2) células manipuladas genéticamente que expresan un solo enzima de biotransformación, es decir una sola isoenzima del citocromo P450 (CYP) y 3) lineas celulares derivadas de hepatomas o de hepatocitos inmortalizados. Los cultivos de hepatocitos humanos son el modelo mas próximo al higado y solamente ellos son capaces de producir el perfil metabólico de un compuesto muy similar al que se obtiene in vivo. Sin embargo, el acceso tan limitado a muestras de tejido hepático humano ha promovido el desarrollo de modelos alternativos a los hepatocitos humanos. De los otros modelos celulares hepáticos de que se dispone, tanto las células de hepatomas, como los hepatocitos inmoralizados muestran, en general, una muy limitada expresión de las actividades de biotransformación. Sin embargo, la reexpresión de ciertos factores de transcripción hepáticos en estas lineas celulares constituye una nueva estrategia experimental para conseguir una eficiente transcripción de las isoenzimas del CYP y la recuperación de su competencia metabólica. Hoy en día, los modelos in vitro hepáticos de origen humano representan la mejor herramienta para abordar los estudios de toxicidad hepática y predecir el metabolismo de nuevas moléculas en el hombre, dada su simplicidad, disponibilidad, bajo coste y el fácil control de múltiples factores y variables (AU)