Dihydromyricetin confers cerebroprotection against subarachnoid hemorrhage via the Nrf2-dependent Prx2 signaling cascade.

BACKGROUND: Several clinical and experimental studies have shown that therapeutic strategies targeting oxidative damage are beneficial for subarachnoid hemorrhage (SAH). A brain-permeable flavonoid, dihydromyricetin (DHM), can modulate redox/oxidative stress and has cerebroprotective effects in several neurological disorders. The effects of DHM on post-SAH early brain injury (EBI) and the underlying mechanism have yet to be clarified. PURPOSE: This work investigated a potential role for DHM in SAH, together with the underlying mechanisms. METHODS: Cerebroprotection by DHM was studied using a SAH rat model and primary cortical neurons. Atorvastatin (Ato) was a positive control drug in this investigation. The effects of DHM on behavior after SAH were evaluated by performing the neurological rotarod and Morris water maze tests, as well as by examining its effects on brain morphology and on the molecular and functional phenotypes of primary cortical neurons using dichlorodihydrofluorescein diacetate (DCFH-DA), immunofluorescent staining, biochemical analysis, and Western blot. RESULTS: DHM was found to significantly reduce the amount of reactive oxygen species (ROS), suppress mitochondrial disruption, and increase intrinsic antioxidant enzymatic activity following SAH. DHM also significantly reduced neuronal apoptosis in SAH rats and improved short- and long-term neurological functions. DHM induced significant increases in peroxiredoxin 2 (Prx2) and nuclear factor erythroid 2-related factor 2 (Nrf2) expression, while decreasing phosphorylation of p38 and apoptotic signal-regulated kinase 1 (ASK1). In contrast, reduction of Prx2 expression using small interfering ribonucleic acid or by inhibiting Nrf2 with ML385 attenuated the neuroprotective effect of DHM against SAH. Moreover, DHM dose-dependently inhibited oxidative damage, decreased neuronal apoptosis, and increased the viability of primary cultured neurons in vitro. These positive effects were associated with Nrf2 activation and stimulation of Prx2 signaling, whereas ML385 attenuated the beneficial effects. CONCLUSION: These results reveal that DHM protects against SAH primarily by modulating the Prx2 signaling cascade through the Nrf2-dependent pathway. Hence, DHM could be a valuable therapeutic candidate for SAH treatment.

Isoliquiritigenin mitigates oxidative damage after subarachnoid hemorrhage in vivo and in vitro by regulating Nrf2-dependent Signaling Pathway via Targeting of SIRT1.

BACKGROUND: Oxidative stress is a crucial factor leading to subarachnoid hemorrhage (SAH)-induced early brain injury (EBI). Isoliquiritigenin has been verified as a powerful anti-oxidant in a variety of diseases models and can activate sirtuin 1 and nuclear factor-erythroid 2-related factor 2 (Nrf2) pathways. However, the effects of isoliquiritigenin against EBI after SAH and the underlying mechanisms remain elusive. PURPOSE: The primary goal of this study is to verify the therapeutic effects of isoliquiritigenin on EBI after SAH and the possible molecular mechanisms. STUDY DESIGN: A prechiasmatic cistern SAH model in rats and a hemoglobin incubation SAH model in primary neurons were established. Isoliquiritigenin was administered after SAH induction. EX527 was employed to inhibit sirtuin 1 activation and ML385 was used to suppress Nrf2 signaling. METHODS: In our study, neurological scores, brain edema, biochemical estimation, western blotting, and histopathological study were performed to explore the therapeutic action of isoliquiritigenin against SAH. RESULTS: Our data revealed that isoliquiritigenin significantly mitigated oxidative damage after SAH as evidenced by decreased reactive oxygen species overproduction and enhanced intrinsic anti-oxidative system. Concomitant with the reduced oxidative insults, isoliquiritigenin improved neurological function and reduced neuronal death in the early period after SAH. Additionally, isoliquiritigenin administration significantly enhanced Nrf2 and sirtuin 1 expressions. Inhibition of Nrf2 by ML385 reversed the anti-oxidative and neuroprotective effects of isoliquiritigenin against SAH. Moreover, inhibiting sirtuin 1 by EX527 pretreatment suppressed isoliquiritigenin-induced Nrf2-dependent pathway and abated the cerebroprotective effects of isoliquiritigenin. In primary cortical neurons, isoliquiritigenin treatment also ameliorated oxidative insults and repressed neuronal degeneration. The beneficial aspects of isoliquiritigenin were attributed to the promotion of sirtuin 1 and Nrf2 signaling pathways and were counteracted by EX527. CONCLUSION: Our findings suggest that isoliquiritigenin exerts cerebroprotective effects against SAH-induced oxidative insults by modulating the Nrf2-mediated anti-oxidant signaling in part through sirtuin 1 activation. Isoliquiritigenin might be a new potential drug candidate for SAH.

Fucoxanthin Mitigates Subarachnoid Hemorrhage-Induced Oxidative Damage via Sirtuin 1-Dependent Pathway.

Oxidative stress is a key component of the pathological cascade in subarachnoid hemorrhage (SAH). Fucoxanthin (Fx) possesses a strong antioxidant property and has shown neuroprotective effects in acute brain injuries such as ischemic stroke and traumatic brain injury. Here, we investigated the beneficial effects of Fx against SAH-induced oxidative insults and the possible molecular mechanisms. Our data showed that Fx could significantly inhibit SAH-induced reactive oxygen species production and lipid peroxidation, and restore the impairment of endogenous antioxidant enzymes activities. In addition, Fx supplementation improved mitochondrial morphology, ameliorated neural apoptosis, and reduced brain edema after SAH. Moreover, Fx administration exerted an improvement in short-term and long-term neurobehavior functions after SAH. Mechanistically, Fx inhibited oxidative damage and brain injury after SAH by deacetylation of forkhead transcription factors of the O class and p53 via sirtuin 1 (Sirt1) activation. EX527, a selective Sirt1 inhibitor, significantly abated Fx-induced Sirt1 activation and abrogated the antioxidant and neuroprotective effects of Fx after SAH. In primary neurons, Fx similarly suppressed oxidative insults and improved cell viability. These effects were associated with Sirt1 activation and were reversed by EX527 treatment. Taken together, our study explored that Fx provided protection against SAH-induced oxidative insults by inducing Sirt1 signaling, indicating that Fx might serve as a potential therapeutic drug for SAH.

Astaxanthin offers neuroprotection and reduces neuroinflammation in experimental subarachnoid hemorrhage.

BACKGROUND: Neuroinflammation has been proven to play a crucial role in early brain injury pathogenesis and represents a target for treatment of subarachnoid hemorrhage (SAH). Astaxanthin (ATX), a dietary carotenoid, has been shown to have powerful anti-inflammation property in various models of tissue injury. However, the potential effects of ATX on neuroinflammation in SAH remain uninvestigated. The goal of this study was to investigate the protective effects of ATX on neuroinflammation in a rat prechiasmatic cistern SAH model. METHODS: Rats were randomly distributed into multiple groups undergoing the sham surgery or SAH procedures, and ATX (25 mg/kg or 75 mg/kg) or equal volume of vehicle was given by oral gavage at 30 min after SAH. All rats were sacrificed at 24 h after SAH. Neurologic scores, brain water content, blood-brain barrier permeability, and neuronal cell death were examined. Brain inflammation was evaluated by means of expression changes in myeloperoxidase, cytokines (interleukin-1ß, tumor necrosis factor-α), adhesion molecules (intercellular adhesion molecule-1), and nuclear factor kappa B DNA-binding activity. RESULTS: Our data indicated that post-SAH treatment with high dose of ATX could significantly downregulate the increased nuclear factor kappa B activity and the expression of inflammatory cytokines and intercellular adhesion molecule-1 in both messenger RNA transcription and protein synthesis. Moreover, these beneficial effects lead to the amelioration of the secondary brain injury cascades including cerebral edema, blood-brain barrier disruption, neurological dysfunction, and neuronal degeneration. CONCLUSIONS: These results indicate that ATX treatment is neuroprotective against SAH, possibly through suppression of cerebral inflammation.

Resveratrol prevents neuronal apoptosis in an early brain injury model.

BACKGROUND: Resveratrol has been shown to attenuate cerebral vasospasm after subarachnoid hemorrhage (SAH); however, no study has explored its neuroprotective effect in early brain injury (EBI) after experimental SAH. The aim of this study was to evaluate the antiapoptotic function of resveratrol in EBI and its relationship with the PI3K/Akt survival pathway. METHODS: Experimental SAH was induced in adult male rats by prechiasmatic cistern injection. Control and SAH rats were divided into six groups and treated with low (20 mg/kg) or high (60 mg/kg) concentrations of resveratrol with or without LY294002 cotreatment. Brain samples of the rats were analyzed by immunohistochemistry, immunofluorescence staining, Western blotting, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assays. RESULTS: High-concentration but not low-concentration resveratrol treatment in SAH rats led to a significant increase in phosphorylated Akt (p-Akt) protein levels compared with SAH rats without treatment. In addition, p-Akt-positive cells mainly colocalized with NeuN-positive cells. Neuronal apoptosis in SAH rat brain was attenuated by high-concentration resveratrol treatment. The antiapoptotic effect of resveratrol in SAH rats could be partially abrogated by the PI3K/Akt signaling inhibitor LY294002. CONCLUSIONS: Our results show that resveratrol has an antiapoptotic effect in EBI and that resveratrol might act through the PI3K/Akt signaling pathway.

[Yimusake Tablet: safe and efficacious for premature ejaculation].

OBJECTIVE: To objectively evaluate the efficacy and safety of Yimusake Tablet in the treatment of premature ejaculation (PE) through a multi-centered large-sample trial. METHODS: We conducted a multi-centered, open, fixed-dose, and self-compared clinical trial among 300 patients with diagnosed PE. The trial lasted 12 weeks, including 4 weeks without any medication and 8 weeks of treatment with Yimusake Tablet, 2 pills (1 g) per night. We observed the intravaginal ejaculation latency time (IELT) before and after treatment, evaluated the safety of medication, and performed a questionnaire investigation on the patients' satisfaction. RESULTS: Of the 300 PE patients, 288 accomplished the clinical trial. The patients ranged in age from 22 to 60 years, averaging at 31.6 years. The mean IELT of the patient was 62.5 seconds at baseline, 168.9 seconds after 4 weeks of treatment with Yimusake Tablet, and 222.2 seconds after 8 weeks of medication. Among the 157 patients with normal erectile function (IIEF >21), the mean IELT was 71.4 seconds before treatment, 147.4 seconds after 4 weeks of medication, and 172.5 seconds after 8 weeks of medication. The patients' satisfaction was significantly increased after treatment. Those complicated by mild to moderate erectile dysfunction achieved different degrees of improvement in the IIEF-5 score, with a mean increase of 3.8. Only a few patients experienced mild adverse events, including constipation, dry mouth, nose bleeding, abdominal pain, and lumbosacral pain, which were all relieved without drug withdrawal. CONCLUSION: Yimusake Tablet is a safe and effective medicine for the treatment of PE.

Femoral bone transport by a monolateral external fixator with or without the use of intramedullary nail: a single-department retrospective study.

BACKGROUNDS: Treatment for bone defect remains a challenge for orthopedists. Bone transport gives an effective alternative, which can be performed with an external fixator alone or combined with an intramedullary nail. Each has its advantages and disadvantages. We present a retrospective study to find out the optimal choice by evaluating the outcomes of treatment for femoral bone defect with two methods. METHODS: Two groups of patients, the monolateral external fixator alone (group A, n = 13) and the monolateral external fixator combined with intramedullary nail (group B, n = 15), were compared. Duration of the external fixator, external fixator index, radiographic consolidation index, complication, and total cost for treatment was also recorded. A modified classification of the Association for the Study and Application of the Method of Ilizarov (ASAMI) was used to assess results in two groups of patients; another SF-36 health survey questionnaire was used to assess the life qualities patients of two groups. RESULTS: Healing was achieved in 13/13 and 13/15 of the two groups, respectively. The rates of complications were significantly higher in the group A. Two patients performed amputations because of persistent deep infections in group B. Statistically significant difference was found when comparing ASAMI scores and categories of the SF-36 health survey. CONCLUSIONS: Bone transport by monolateral external fixator with the use of intramedullary nail reduces the incidence of complication and the duration of external fixator time that give patients a better life quality in both physical and emotional. However, if chronic osteitis exists, bone transport should be treated with monolateral external fixator alone due to a lower rate of amputations.