Dehydroepiandrosterone rehabilitate BRL‐3A cells oxidative stress damage induced by hydrogen peroxide

Dehydroepiandrosterone modulates the PTEN/PI3K/AKT signaling pathway to alleviate 4-vinylcyclohexene diepoxide-induced premature ovarian insufficiency in rats

Dehydroepiandrosterone (DHEA) is frequently integrated as an adjuvant in over a quarter of controlled ovarian hyperstimulation (COH) protocols, despite the ongoing debate regarding its impact. This study aimed to evaluate the efficacy and mechanism of action of DHEA on ovarian follicular development and ovarian response in rats with varying ovarian reserves. The study involved 75 rats categorized into 15 distinct groups. The ovarian tissues of rats in both the normal ovarian reserve group and the premature ovarian insufficiency (POI) group, induced by 4-vinylcyclohexene diepoxide (VCD) injection, were subjected to histomorphological and biochemical analyses following the administration of DHEA, either alone or in combination with COH. Follicle counting was performed on histological sections obtained from various tissues. Serum concentrations of anti-Müllerian hormone (AMH) and the quantification of specific proteins in ovarian tissue, including phosphatase and tensin homolog of chromosome 10 (PTEN), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (pAKT), cyclooxygenase 2 (COX-2), caspase-3, as well as assessments of total antioxidant status and total oxidant status, were conducted employing the ELISA method. The impact of DHEA exhibited variability based on ovarian reserve. In the POI model, DHEA augmented follicular development and ovarian response to the COH protocol by upregulating the PTEN/PI3K/AKT signaling pathway, mitigating apoptosis, inflammation, and oxidative stress, contrary to its effects in the normal ovarian reserve group. In conclusion, it has been determined that DHEA may exert beneficial effects on ovarian stimulation response by enhancing the initiation of primordial follicles and supporting antral follicle populations.

Dehydroepiandrosterone protects against oleic acid-triggered mitochondrial dysfunction to relieve oxidative stress and inflammation via activation of the AMPK-Nrf2 axis by targeting GPR30 in hepatocytes

Fatty liver hemorrhage syndrome (FLHS) seriously threatens the health and performance of laying hens, and the occurrence and development of FLHS are closely related to oxidative damage and inflammation; thus, diets supplemental with activated substances to relive the oxidative stress and inflammation maybe effectively control the occurrences of FLHS. Dehydroepiandrosterone (DHEA) has beneficial effects in fat-reduction, anti-oxidation and anti-inflammation, and it was widely applied to alleviate multiple metabolic-related diseases; however, there are few reports on whether DHEA can prevent against metabolic-related diseases by modulating oxidative stress and inflammation, especially FLHS in laying hens. Herein, present study aimed to investigate the regulatory actions and potential molecular mechanism of DHEA on inflammation and oxidative stress triggered by oleic acid (OA)-stimulation in primary chicken hepatocytes and chicken hepatocellular carcinoma cell line (LMH). The results showed that DHEA significantly alleviated oxidative stress challenged by OA-stimulation via activation of AMP-activated protein kinase (AMPK)-nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in hepatocytes, which led to relieving effect of DHEA on inflammatory by inhibiting mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NF-κB) signaling pathways. Mechanistically, we found that the activation of AMPK-Nrf2 signaling pathway by DHEA treatment was mediated by G-protein coupled estrogen receptor (GPR30/GPER) in OA-stimulated hepatocytes. Further investigation found that DHEA activated the GPR30-mediated AMPK-Nrf2 signaling pathways to increase antioxidant capacity and inhibit mitochondrial reactive oxygen species (ROS) overproduction, which thereby inhibiting the activation of ROS-induced MAPK and NF-κB signaling pathways in OA-stimulated hepatocytes. Overall, these data demonstrated that DHEA attenuates the oxidative stress and inflammation triggered by OA-stimulation, and these beneficial effects of DHEA are achieved by activating the GPR30-mediated AMPK-Nrf2 signaling to prevent the impairment of mitochondrial function, and thereby inhibiting the activation of ROS-induced MAPK and NF-κB signaling pathways in hepatocytes. These results revealed the effects and mechanisms of DHEA on oxidative stress and inflammation, and also provide substantial information to support it as a potential nutritional supplement in preventing the occurrences of FLHS in laying hens and other metabolic-related diseases in animals and humans.

Protective Mechanism of Gandou Decoction in a Copper-Laden Hepatolenticular Degeneration Model: In Vitro Pharmacology and Cell Metabolomics

Gandou decoction (GDD) is a classic prescription for the treatment of hepatolenticular degeneration (HLD) in China; however, the liver-protecting mechanism of this prescription needs further evaluation. In the present study, we explored the protective mechanisms of GDD in a copper-laden HLD model using integrated pharmacology and cellular metabolomics in vitro. The results revealed that GDD could significantly promote copper excretion in copper-laden HLD model cells and improve the ultrastructural changes in hepatocytes. In addition, GDD could decrease the extent of lipid peroxidation, levels of reactive oxygen species, and the release rate of lactate dehydrogenase while increasing the activity of superoxide dismutase and the ratio of glutathione to oxidized glutathione in the copper-laden HLD model cells. On conducting statistical analysis of significant metabolic changes, 47 biomarkers and 30 related metabolic pathways were screened as pharmacological reactions induced by GDD in HLD model cells. d-glutamate and d-glutamine metabolic pathways showed the highest importance and significance among the 30 metabolic pathways, and the differential expression levels of the glutamine synthetase (GS) and the renal type and liver type GLS (GLS1 and GLS2) proteins were verified by Western blotting. Collectively, our data established the underlying mechanism of GDD therapy, such as the promotion of copper excretion and improvement in oxidative stress by regulating the expressions of GS, GLS1, and GLS2 protein to protect hepatocytes from injury.

Effects of phloridzin on blood glucose and key enzyme G-6-Pase of gluconeogenesis in mice

The effects of phloridzin (PHL), main component of Malus hupehensis (MH) tea leaves, on blood glucose (BG) and glucose-6-phosphatase (G-6-Pase) were investigated to provide a basis for finding a scheme of stabilizing BG. Glucose uptake of insulin resistant HepG2 cells was measured by glucose oxidase method. Glucose tolerance, fasting BG (FBG) and postprandial BG (PBG) were determined by BG test strips. The expression of G-6-Pase was detected by Western blot. The results showed that glucose uptake was enhanced and the expression of G-6-Pase was inhibited by PHL in insulin resistant HepG2 cells. Glucose tolerance was enhanced, FBG level was increased and PBG level was decreased by PHL in mice. The expression of G-6-Pase in the liver was enhanced under fasting state, and was inhibited by the low and medium dose under postprandial state. It indicated that PHL has a positive effect on stabilizing BG in mice, which is related to bidirectional regulation of G-6-Pase activity. PRACTICAL APPLICATIONS: Malus hupehensis, edible and medicinal plant, which has been proved by long-term application and experiments that it has a good effect on stabilizing blood glucose, preventing diabetes and adjuvant treatment. Its effect is closely related to its main component PHL. Thus, MH can be used as a dietary regulating drink for daily life to maintain blood glucose. Its main ingredient is PHL, which can be developed as a candidate drug for diabetes treatment.

Hepatoprotective effect of Sophora moorcroftiana (Benth.) Benth.Ex baker seeds in vivo and in vitro

The leguminosae of Sophora moorcroftiana (Benth.) Benth.ex Baker is a drought-resistant endemic Sophora shrub species from the Qinghai-Tibet Plateau, and its seeds have hepatoprotective effects. To study the effect of S. moorcroftiana seeds on liver injury and the molecular mechanism underlying the beneficial effects, liquid chromatography-mass spectrometry was used to detect the main active components in the ethanol extract of S. moorcroftiana seeds (SM). Male mice were divided into six groups (n = 8): normal control (NC), CCl₄, SM (50, 100, 200 mg/kg), and dimethyl diphenyl bicarboxylate (150 mg/kg) groups. Mice were treated as indicated (once/day, orally) for 14 days, and CCl₄ (2 mL/kg) was administered intraperitoneally. The serum and liver of mice were used for biochemical assays. To explore the underlying mechanism, HepG2 cells were treated with SM, stimulated with tert-butyl hydroperoxide (t-BHP, 50 μM), and analyzed by Western blotting. The major active compounds of SM were alkaloids including 22 compounds. Serum alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) decreased in the SM (200 mg/kg) group. SM can activate the expression of pregnane X receptor (PXR) and downstream molecules cytochrome P4503A11 enzyme (CYP3A11), UDP glucuronosyltransferase 1 family polypeptide A 1 (UGT1A1), and inhibit the multidrug resistance protein 2 (MRP2). In addition, SM improved cell viability in t-BHP-induced HepG2 cells (64% to 83%) and decreased the activation of the mitogen-activated protein kinase (MAPK) pathway. The main compounds in SM were alkaloids. SM showed hepatoprotective effects possibly mediated by the suppression of oxidative stress through the MAPK pathway.

Phenols fragment of Veronica ciliata Fisch. ameliorate free radical-induced nonalcoholic fatty liver disease by mediating PI3K/Akt signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Veronica ciliata Fisch. is used in numerous of Tibetan medicine prescriptions because of its hepatoprotective effect.

AIMS OF THIS STUDY

Here, we aimed to investigate the hepatoprotective effect and mechanism of phenolic fraction (PF) of V. ciliata Fisch. on liver injury induced by free radical.

MATERIALS AND METHODS

BRL 3A cells were pre-treated with PF and luteolin (Lut) following tert-butyl hydroperoxide (t-BHP) treatment. The cell viability, lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation, apoptosis, cell cycle and autophagy were analyzed. Apoptotic, inflammatory, and autophagy,- related proteins were analyzed using Western blotting. The combination of molecular docking and drug affinity targeting experiments (DARTS) were first utilized to analysis the target protein of Lut.

RESULTS

PF effectively suppressed t-BHP-induced apoptosis caused by mitochondrial dysfunction, which were associated with inhibiting ROS generation. Further investigation indicated that PF significantly suppressed apoptosis, inflammation, and autophagy by regulating the expression of related proteins. The results of molecular docking and drug affinity targeting experiments (DARTS) revealed that PI3K was the target protein of PF and Lut. Further studies have shown that PF relieved liver injury induced by t-BHP via suppressing phosphorylated expression of PI3K.

CONCLUSION

Our results indicate that PF effectively protect against hepatotoxicity induced by t-BHP through inhibiting the abnormal activation of PI3K-Akt signaling pathway and highlight the health benefits of PF regarding oxidative stress, proving it to be an important source of bioactive compounds associated with Nonalcoholic fatty liver disease (NAFLD).

Dehydroepiandrosterone (DHEA) and its Sulphate (DHEAS) in Alzheimer's Disease

BACKGROUND

Neurosteroids Dehydroepiandrosterone (DHEA) and Dehydroepiandrosterone Sulphate (DHEAS) are involved in many important brain functions, including neuronal plasticity and survival, cognition and behavior, demonstrating preventive and therapeutic potential in different neuropsychiatric and neurodegenerative disorders, including Alzheimer's disease.

OBJECTIVE

The aim of the article was to provide a comprehensive overview of the literature on the involvement of DHEA and DHEAS in Alzheimer's disease.

METHODS

PubMed and MEDLINE databases were searched for relevant literature. The articles were selected considering their titles and abstracts. In the selected full texts, lists of references were searched manually for additional articles.

RESULTS

We performed a systematic review of the studies investigating the role of DHEA and DHEAS in various in vitro and animal models, as well as in patients with Alzheimer's disease, and provided a comprehensive discussion on their potential preventive and therapeutic applications.

CONCLUSION

Despite mixed results, the findings of various preclinical studies are generally supportive of the involvement of DHEA and DHEAS in the pathophysiology of Alzheimer's disease, showing some promise for potential benefits of these neurosteroids in the prevention and treatment. However, so far small clinical trials brought little evidence to support their therapy in AD. Therefore, large-scale human studies are needed to elucidate the specific effects of DHEA and DHEAS and their mechanisms of action, prior to their applications in clinical practice.

Protective effect of apple phlorizin on hydrogen peroxide-induced cell damage in HepG2 cells

Apple phlorizin has many biological activities, such as antioxidant and liver protection. The present study aimed to evaluate the roles of apple phlorizin against hydrogen peroxide (H₂ O₂ )-induced oxidative damage in HepG2 cells. In this study, treatment with apple phlorizin (100 and 150 μg/ml) decreased the production of reactive oxygen species and alleviated apoptosis as well as DNA damage in H₂ O₂ -induced HepG2 cells. These effects were associated with the increased activity of antioxidant enzymes, enhanced the ARE-driven phase II antioxidant gene expression and its upstream Nrf2 protein expression, and decreased apoptosis-related gene expression. However, the phase II antioxidant gene expression and Nrf2 protein expression upregulated by phlorizin were reversed by Nrf2 shRNA transfection. These results showed that phlorizin relieves oxidative stress, DNA damage, and apoptosis in H₂ O₂ -induced HepG2 cells, at least partially, by regulating the expression of Nrf2 protein and apoptosis-related genes. PRACTICAL APPLICATIONS: Apple phlorizin is a polyphenol compound extracted from apple or apple juice. This report highlighted a protective effect of phlorizin on antioxidant stress, DNA damage, and apoptosis in H₂ O₂ -induced HepG2 cells. These results suggested that phlorizin may be developed for functional foods.

Dehydroepiandrosterone Prevents H2O2-Induced BRL-3A Cell Oxidative Damage through Activation of PI3K/Akt Pathways rather than MAPK Pathways

Dehydroepiandrosterone (DHEA) is a popular dietary supplement that has well-known benefits in animals and humans, but there is not enough information about the mechanisms underlying its effects. The present study aimed at investigating these mechanisms through in vitro experiments on the effects of DHEA on rat liver BRL-3A cells exposed to oxidative stress through H₂O₂. The findings showed that DHEA increased the antioxidant enzyme activity, decreased ROS generation, and inhibited apoptosis in H₂O₂-treated cells. These effects of DHEA were not observed when the cells were pretreated with known antagonists of sex hormones (Trilostane, Flutamide, or Fulvestrant). Furthermore, treatment with estradiol and testosterone did not have the same protective effects as DHEA. Thus, the beneficial effects of DHEA were associated with mechanisms that were independent of steroid hormone pathways. With regard to the mechanism underlying the antiapoptotic effect of DHEA, pretreatment with DHEA was found to induce a significant decrease in the protein expression of Bax and caspase-3 and a significant increase in the protein expression of PI3K and p-Akt in H₂O₂-treated BRL-3A cells. These effects of DHEA were abolished when the cells were pretreated with the PI3K inhibitor LY294002. No changes were observed on the p-ERK1/2, p-p38, and p-JNK protein levels in H₂O₂-induced BRL-3A cells pretreated with DHEA. In conclusion, our data demonstrate that DHEA protects BRL-3A cells against H₂O₂-induced oxidative stress and apoptosis through mechanisms that do not involve its biotransformation into steroid hormones or the activation of sex hormone receptors. Importantly, the protective effect of DHEA on BRL-3A cells was mainly associated with PI3K/Akt signaling pathways, rather than MAPK signaling pathways.

Aspirin eugenol ester attenuates oxidative injury of vascular endothelial cells by regulating NOS and Nrf2 signalling pathways

BACKGROUND AND PURPOSE

Aspirin eugenol ester (AEE) is a new drug compound synthesized by combining aspirin with eugenol. It was reported to possess anti-thrombotic, anti-atherosclerotic, and anti-oxidative effects. However, its molecular mechanism against oxidative injury is unclear. This study investigated how AEE affected the oxidative injury of vascular endothelial cells in vivo and in vitro.

EXPERIMENTAL APPROACH

A hamster model of atherosclerosis induced by a high fat diet (HFD) and an in vitro model of oxidative stress, H₂ O₂ -induced apoptosis of HUVECs, were used to investigate the anti-oxidative effects of AEE.

KEY RESULTS

AEE significantly reduced the stimulatory effect of HFD on malondialdehyde, the inhibitory effect of HFD on SOD activity and GSH/GSSG ratio, and the overexpression of inducible NOS (iNOS) in the aorta. In vitro, incubation of HUVECs with H₂ O₂ led their apoptosis, dysfunctions of the NO systems (including increased iNOS activity, decreased endothelial NOS activity, and increased production of NO), an imbalance in calcium homeostasis and energy metabolism with an increase in intracellular free calcium and decrease in ATP, and a down-regulation of Nrf2. In contrast, in the HUVECs pretreated with 1 μM AEE for 24 hr, the above adverse effects induced by H₂ O₂ were significantly ameliorated. Moreover, the decrease in NO production and activity of iNOS induced by AEE was significantly attenuated in Nrf2-inhibited HUVECs.

CONCLUSION AND IMPLICATION

AEE protects vascular endothelial cells from oxidative injury by regulating NOS and Nrf2 signalling pathways. This suggests that AEE is a novel potential agent for the prevention of atherosclerosis.