Current therapies for ischemic stroke are insufficient due to the lack of specific drugs. This study aimed to investigate the protective activity of polyphenol extracts from Terminalia chebula against cerebral ischemia-reperfusion induced damage. Polyphenols of ethyl acetate and n-butanol fractions were extracted from T. chebula. BV2 microglial cells exposed to oxygen-glucose deprivation/reoxygenation and mice subjected to middle cerebral artery occlusion/reperfusion were treated by TPE and TPB. Cell viability, cell morphology, apoptosis, mitochondrial membrane potential, enzyme activity and signaling pathway related to oxidative stress were observed. We found that TPE and TPB showed strong antioxidant activity in vitro. The protective effects of TPE and TPB on cerebral ischemia-reperfusion injury were demonstrated by enhanced antioxidant enzyme activities, elevated level of the nucleus transportation of nuclear factor erythroid 2-related factor 2 and expressions of antioxidant proteins, with a simultaneous reduction in cell apoptosis and reactive oxygen species level. In conclusion, TPE and TPB exert neuroprotective effects by stimulating the Nrf2 signaling pathway, thereby inhibiting apoptosis.
Excessive reactive oxygen species (ROS) production contributes to brain ischemia/reperfusion (I/R) injury through many mechanisms including inflammation, apoptosis, and cellular necrosis. Chebulic acid (CA) isolated from Terminalia chebula has been found to have various biological effects, such as antioxidants. In this study, we investigated the mechanism of the anti-hypoxic neuroprotective effect of CA in vitro and in vivo. The results showed that CA could protect against oxygen-glucose deprivation/reoxygenation (OGD/R) induced neurotoxicity in SH-SY5Y cells, as evidenced by the enhancement of cell viability and improvement of total superoxide dismutase (T-SOD) in SH-SY5Y cells. CA also attenuated OGD/R-induced elevations of malondialdehyde (MDA) and ROS in SH-SY5Y cells. Nuclear factor-E2-related factor 2 (Nrf2) is one of the key regulators of endogenous antioxidant defense. CA acted as antioxidants indirectly by upregulating antioxidant-responsive-element (ARE) and Nrf2 nuclear translocation to relieve OGD/R-induced oxidative damage. Furthermore, the results showed that CA treatment resulted in a significant decrease in ischemic infarct volume and improved performance in the motor ability of mice 24 h after stroke. This study provides a new niche targeting drug to oppose ischemic stroke and reveals the promising potential of CA for the control of ischemic stroke in humans.
Background: Cerebrovascular lesions could induce affective disorders; however, the depression- and anxiety-related symptoms caused by chronic cerebral hypoperfusion (CCH) and the roles of different hyperpolarization-activated cyclic nucleotide-gated (HCN), KCNQ and G proteincoupled inwardly rectifying potassium (GirK) channel subunits in these pathological processes have been poorly elucidated so far. Objective: To investigate the behavioral change and the alteration of HCN, KCNQ, and GirK subunits in amygdale rats suffering from CCH. Methods: Permanent bilateral occlusion of the common carotid arteries was used to induce CCH. Anxiety and depression levels were assessed by the elevated plus maze test, sucrose preference test and forced swimming test to classify rats as highly anxious or depressive ‘susceptibility’ vs. ‘unsusceptibility’. The expression of brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor B (TrKB), HCN1/2, KCNQ2/3, and GirK1/2/3 were quantified by Western blotting. Results: The main emotional change caused by 4 weeks of CCH is likely to be anxiety-like behavior (50%), accompanied by a down-regulation of BDNF and TrKB expression in amygdale. The increase of HCN1 and decrease of KCNQ3 expression in amygdale may be factors to blame for anxiety- like symptom caused by CCH, and the increase of KCNQ2 and Girk1 expression in amygdale may play a role in resilience to the anxiety induced by CCH. Conclusion: The different subunits of HCN, KCNQ and GirK channels in amygdale may contribute to distinct response to aversive stimuli or stress induced by CCH that evokes divergent influences on anxiety-like behavior in rats.
Liver cancer remains the leading cause of cancer-related deaths; however, current therapeutic drugs are largely ineffective. This study aimed to investigate the anticancer activity of fiscalin B, a compound extracted from marine fungi, against HepG2 cells and further explore the underlying mechanisms. Our findings revealed that fiscalin B treatment produced overloaded reactive oxygen species (ROS) and induced apoptosis in HepG2 cells, further disrupt the mitochondrial membrane potential, inducing mitochondrial dysfunction. Fluorescence microscopy revealed alterations in the distribution of TOM20 and activation of lysosomes in fiscalin B-treated HepG2 cells. The disruption of mitochondria following fiscalin B treatment marked an improved mitophagy. Moreover, fiscalin B induced G0/G1 cell cycle arrest in HepG2 cells by increasing the phosphorylation of p70S6K and S6, thus affecting the expression of key cell cycle regulators. Overall, fiscalin B exerts an anticancer effect by inducing mitochondria-modulated autophagic cell death and cell cycle arrest in hepatocellular carcinoma (HCC) cells.