Estrone-mediated lowering of ROS and NOX4 improves endothelial function in ovariectomized wistar rats.

Estrone (E1) constitutes the primary component in oral conjugated equine estrogens (CEEs) and serves as the principal estrogen precursor in the female circulation in the post-menopause. E1 induces endothelium-dependent vasodilation and activate PI3K/NO/cGMP signaling. To assess whether E1 mitigates vascular dysfunction associated with postmenopause and explore the underlying mechanisms, we examined the vascular effects of E1 in ovariectomized (OVX) rats, a postmenopausal experimental model. Blood pressure was measured using tail-cuff plethysmography, and aortic rings were isolated to assess responses to phenylephrine, acetylcholine (ACh), and sodium nitroprusside. Responses to ACh in rings pre-incubated with superoxide dismutase (SOD), catalase (CAT), or apocynin were also evaluated. Protein expression of SOD, CAT, NOX1, NOX2, and NOX4 was determined by Western blotting. E1 treatment resulted in decreased body weight and retroperitoneal fat, increased uterine weight, and prevented elevated blood pressure in the OVX group. Furthermore, E1 improved endothelium-dependent ACh vasodilation, activated compensatory antioxidant mechanisms - i.e. increased SOD and CAT antioxidant enzymes activity, and decreased NOX4 expression. This, in turn, helped prevent oxidative stress and endothelial dysfunction in OVX rats. Additionally, E1 treatment reversed the increased total LDL cholesterol observed in the OVX group. The findings underscore protective effects of E1 on the cardiovascular system, counteracting OVX-related oxidative stress and endothelial dysfunction in Wistar rats. E1 exhibits promising therapeutic benefits for managing cardiovascular health, particularly in postmenopausal conditions.

Anti-inflammatory and antinociceptive activity profile of a new lead compound - LQFM219.

LQFM219 is a molecule designed from celecoxibe (COX-2 inhibitor) and darbufelone (inhibitor of COX-2 and 5-LOX) lead compounds through a molecular hybridisation strategy. Therefore, this work aimed to investigate the antinociceptive and anti-inflammatory activities of this new hybrid compound. The acute oral systemic toxicity of LQFM219 was evaluated via the neutral red uptake assay. Acetic acid-induced abdominal writhing and CFA-induced mechanical hyperalgesia were performed to evaluate the antinociceptive activity, and the anti-oedematogenic activity was studied by CFA-induced paw oedema and croton oil-induced ear oedema. Moreover, the acute anti-inflammatory activity was determined by carrageenan-induced pleurisy. In addition, cell migration, myeloperoxidase enzyme activity, and TNF-α and IL-1ß levels were determined in pleural exudate. Moreover, a redox assay was conducted using electroanalytical and DPPH methods. The results demonstrated that LQFM219 was classified as GHS category 4, and it showed better free radical scavenger activity compared to BHT. Besides, LQFM219 decreased the number of writhings induced by acetic acid and the response to the mechanical stimulus in the CFA-induced mechanical hyperalgesia test. Furthermore, LQFM219 reduced oedema formation, cell migration, and IL-1ß and TNF-α levels in the pleural cavity and inhibited myeloperoxidase enzyme activity. Thus, our study provides that the new pyrazole derivative, LQFM219, demonstrated low toxicity, antinociceptive and anti-inflammatory potential in vitro and in vivo.

The Influence of Na(+), K(+)-ATPase on Glutamate Signaling in Neurodegenerative Diseases and Senescence.

Decreased Na(+), K(+)-ATPase (NKA) activity causes energy deficiency, which is commonly observed in neurodegenerative diseases. The NKA is constituted of three subunits: α, ß, and γ, with four distinct isoforms of the catalytic α subunit (α1-4). Genetic mutations in the ATP1A2 gene and ATP1A3 gene, encoding the α2 and α3 subunit isoforms, respectively can cause distinct neurological disorders, concurrent to impaired NKA activity. Within the central nervous system (CNS), the α2 isoform is expressed mostly in glial cells and the α3 isoform is neuron-specific. Mutations in ATP1A2 gene can result in familial hemiplegic migraine (FHM2), while mutations in the ATP1A3 gene can cause Rapid-onset dystonia-Parkinsonism (RDP) and alternating hemiplegia of childhood (AHC), as well as the cerebellar ataxia, areflexia, pescavus, optic atrophy and sensorineural hearing loss (CAPOS) syndrome. Data indicates that the central glutamatergic system is affected by mutations in the α2 isoform, however further investigations are required to establish a connection to mutations in the α3 isoform, especially given the diagnostic confusion and overlap with glutamate transporter disease. The age-related decline in brain α2∕3 activity may arise from changes in the cyclic guanosine monophosphate (cGMP) and cGMP-dependent protein kinase (PKG) pathway. Glutamate, through nitric oxide synthase (NOS), cGMP and PKG, stimulates brain α2∕3 activity, with the glutamatergic N-methyl-D-aspartate (NMDA) receptor cascade able to drive an adaptive, neuroprotective response to inflammatory and challenging stimuli, including amyloid-ß. Here we review the NKA, both as an ion pump as well as a receptor that interacts with NMDA, including the role of NKA subunits mutations. Failure of the NKA-associated adaptive response mechanisms may render neurons more susceptible to degeneration over the course of aging.

The larvicidal activity of Agave sisalana against L4 larvae of Aedes aegypti is mediated by internal necrosis and inhibition of nitric oxide production.

Dengue is a viral disease that affects about 50 million people per year around the world. The aim of this study was to investigate the larvicidal activity of Agave sisalana crude extract in order to develop a new insecticide against Aedes aegypti. In larvicidal activity assays, fourth-stage Ae. aegypti larvae were exposed to different concentrations of A. sisalana crude extract for 3, 6, 12, and 24 h for determining the LC50. Next, we explored its cytotoxic activity by flow cytometry. Furthermore, histological alterations were confirmed by histopathological analysis, and the nitric oxide (NO) production by hemocytes was checked after different periods of exposure to A. sisalana crude extract. The LC50 was 4.5 ± 0.07 mg/mL. In addition, flow cytometry revealed an increase of cellular necrosis (21 and 16.5 % after 12 and 24 h, respectively) in larvae that were exposed to A. sisalana crude extract. The histological analysis revealed cell lysis and destruction of the peritrophic membrane. Furthermore, there was a reduction in the concentration of NO in the hemolymph from larvae exposed to A. sisalana crude extract after 3, 6, and 24 h (5.3 ± 4.3 vs. 22.7 ± 5.2 µM, 4.3 ± 5.5 vs. 25.4 ± 6.6 µM, and 6 ± 1.7 vs. 37.1 ± 7.8 µM, respectively). Our findings show that A. sisalana crude extract constitutes an effective larvicidal agent against Ae. aegypti larvae due to its necrotizing activity in hemocytes and inhibition of the NO production.

Neolignan Licarin A presents effect against Leishmania (Leishmania) major associated with immunomodulation in vitro.

Leishmaniasis' treatment is based mostly on pentavalent antimonials or amphotericin B long-term administration, expensive drugs associated with severe side effects. Considering these aforementioned, the search for alternative effective and safe leishmaniasis treatments is a necessity. This work evaluated a neolignan, licarin A anti-leishmanial activity chemically synthesized by our study group. It was observed that licarin A effectively inhibited Leishmania (Leishmania) major promastigotes (IC50 of 9.59 ± 0.94 µg/mL) growth, by inducing in these parasites genomic DNA fragmentation in a typical death pattern by apoptosis. Additionally, the neolignan proved to be even more active against intracellular amastigotes of the parasite (EC50 of 4.71 ± 0.29 µg/mL), and significantly more effective than meglumine antimoniate (EC50 of 216.2 ± 76.7 µg/mL) used as reference drug. The antiamastigote activity is associated with an immunomodulatory activity, since treatment with licarin A of the infected macrophages induced a decrease in the interleukin (IL)-6 and IL-10 production. This study demonstrates for the first time the antileishmanial activity of licarin A and suggests that the compound may be a promising in the development of a new leishmanicidal agent.