Lappaconitine sulfate inhibits proliferation and induces mitochondrial-mediated apoptosis via regulating PI3K/AKT/GSK3β signaling pathway in HeLa cells

Lappaconitine (LA), a diterpenoid alkaloid extracted from the root of Aconitum sinomontanum Nakai, exhibits broad pharmacological effects, including anti-tumor activity. The inhibitory effect of lappaconitine hydrochloride (LH) on HepG2 and HCT-116 cells and the toxicity of lappaconitine sulfate (LS) on HT-29, A549, and HepG2 cells have been described. But the mechanisms of LA against human cervical cancer HeLa cells still need to be clarified. This study was designed to investigate the effects and molecular mechanisms of lappaconitine sulfate (LS) on the growth inhibition and apoptosis in HeLa cells. The cell viability and proliferation were evaluated using the Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2´-deoxyuridine (EdU) assay, respectively. The cell cycle distribution and apoptosis were detected by flow cytometry analysis and 4', 6-diamidino-2-phenylindole (DAPI) staining. The mitochondrial membrane potential (MMP) was determined through the 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimi-dazolyl carbocyanine iodide (JC-1) staining. The cell cycle arrest-, apoptosis-, and the phosphatidylinositol-3-kinase/protein kinase B/glycogen synthase kinase 3β (PI3K/AKT/GSK3β) pathway-related proteins were estimated by western blot analysis. LS markedly reduced the viability and suppressed the proliferation of HeLa cells. LS induced G0/G1 cell cycle arrest through the inhibition of Cyclin D1, p-Rb, and induction of p21 and p53. Furthermore, LS triggered apoptosis through the activation of mitochondrial-mediated pathway based on decrease of Bcl-2/Bax ratio and MMP and activation of caspase-9/7/3. Additionally, LS led to constitutive downregulation of the PI3K/AKT/GSK3β signaling pathway. Collectively, LS inhibited cell proliferation and induced apoptosis through mitochondrial-mediated pathway by suppression of the PI3K/AKT/GSK3β signaling pathway in HeLa cells.

Protective effects of safranal on hypoxia/reoxygenation-induced injury in H9c2 cardiac myoblasts via the PI3K/AKT/GSK3β signaling pathway

Safranal (SFR), an active ingredient extracted from saffron, exhibits a protective effect on the cardiovascular system. However, the mechanism of SFR against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury has previously not been investigated in vitro. The aim of the present study was therefore to observe the protective effects of SFR on H/R-induced cardiomyocyte injury and to explore its mechanisms. A H/R injury model of H9c2 cardiac myoblasts was established by administering 800 µmol/l CoCl₂ to H9c2 cells for 24 h and reoxygenating the cells for 4 h to induce hypoxia. H9c2 cardiac myoblasts were pretreated with SFR for 12 h to evaluate the associated protective effects. A Cell Counting Kit-8 assay was used for cell viability detection, and the expression levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), glutathione peroxidase (GSH-px), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and caspase-3, and the intracellular Ca²⁺ concentration were measured using the corresponding commercial kits. Levels of reactive oxygen species (ROS) in the cells were detected using 2,7-dichlorodihydrofluorescein diacetate. Flow cytometry was used to determine the degree of apoptosis and the level of mitochondrial membrane potential (MMP). Moreover, the expression levels of phosphorylated (p-)PI3K, AKT, p-AKT, glycogen synthase kinase 3β (GSK3β), p-GSK3β, Bcl-2, Bax, caspase-3 and cleaved caspase-3 were measured using western blot analysis. Results of the present study demonstrated that the H9c2 cardiac myoblasts treated with SFR exhibited significantly improved levels of viability and significantly reduced levels of ROS, compared with the H/R group. Furthermore, compared with the H/R group, SFR treatment significantly increased the MMP levels and antioxidant enzyme levels, including CAT, SOD and GSH-px; whereas the levels of CK-MB, LDH, MDA and intracellular Ca²⁺ concentration were significantly decreased. Moreover, the results of the present study demonstrated that SFR significantly reduced caspase-3, cleaved caspase-3 and Bax protein expression levels, but upregulated the Bcl-2 protein expression levels. SFR also increased the protein expressions of PI3K/AKT/GSK3β. In summary, the results suggested that SFR may exert a protective effect against H/R-induced cardiomyocyte injury, which occurs in connection with the inhibition of oxidative stress and apoptosis via regulation of the PI3K/AKT/GSK3β signaling pathway.

Protective Effect of GM1 Attenuates Hippocampus and Cortex Apoptosis After Ketamine Exposure in Neonatal Rat via PI3K/AKT/GSK3β Pathway

Ketamine is a widely used analgesic and anesthetic in obstetrics and pediatrics. Ketamine is known to promote neuronal death and cognitive dysfunction in the brains of humans and animals during development. Monosialotetrahexosyl ganglioside (GM1), a promoter of brain development, exerts neuroprotective effects in many neurological disease models. Here, we investigated the neuroprotective effect of GM1 and its potential underlying mechanism against ketamine-induced apoptosis of rats. Seven-day-old Sprague Dawley (SD) rats were randomly divided into the following four groups: (1) group C (control group: normal saline was injected intraperitoneally); (2) group K (ketamine); (3) group GM1 (GM1 was given before normal saline injection); and (4) GM1+K group (received GM1 30 min before continuous exposure to ketamine). Each group contained 15 rats, received six doses of ketamine (20 mg/kg), and was injected with saline every 90 min. The Morris water maze (MWM) test, the number of cortical and hippocampal cells, apoptosis, and AKT/GSK3β pathway were analyzed. To determine whether GM1 exerted its effect via the PI3K/AKT/GSK3β pathway, PC12 cells were incubated with LY294002, a PI3K inhibitor. We found that GM1 protected against ketamine-induced apoptosis in the hippocampus and cortex by reducing the expression of Bcl-2 and Caspase-3, and by increasing the expression of Bax. GM1 treatment increased the expression of p-AKT and p-GSK3β. However, the anti-apoptotic effect of GM1 was eliminated after inhibiting the phosphorylation of AKT. We showed that GM1 lessens ketamine-induced apoptosis in the hippocampus and cortex of young rats by regulating the PI3K/AKT/GSK3β pathway. Taken together, GM1 may be a potential preventive treatment for the neurotoxicity caused by continuous exposure to ketamine.

Sevoflurane alleviates oxygen-glucose deprivation/reoxygenation-induced injury in HT22 cells through regulation of the PI3K/AKT/GSK3β signaling pathway

Sevoflurane (Sev), a volatile anesthetic, has been reported to exhibit beneficial effects on different ischemia/reperfusion (I/R)-injured organs. However, the neuroprotective effect of Sev on cerebral I/R injury is poorly understood. In the present study, the effects of Sev on HT22 cells exposed to oxygen-glucose deprivation/reperfusion (OGD/R) injury are investigated. The present study demonstrated that OGD/R suppressed the cell viability and increased lactate dehydrogenase (LDH) release from the cells, and these effects were attenuated by Sev treatment. The results also demonstrated that Sev alleviated OGD/R-induced cell apoptosis via flow cytometry and caspase-3 activity determination. Biochemical analysis results revealed that Sev significantly protected against OGD/R-induced oxidative stress by reducing ROS generation and improving antioxidant defense markers. Western blot analysis demonstrated that Sev reactivated the PI3K/AKT/glycogen synthase kinase-3β (GSK3β) signaling pathway, which was inhibited by OGD/R. In addition, wortmannin, a selective PI3K inhibitor was used to investigate the underlying pathways. Notably, the neuroprotective effect of Sev on apoptosis and reactive oxygen species production was found to be suppressed by wortmannin. Collectively, these results demonstrated that Sev may protect neuronal cells against OGD/R-induced injury through the activation of the PI3K/AKT/GSK3β signaling pathway. The findings from the present study provide a novel insight into understanding the neuroprotective effect of Sev on cerebral I/R injury.

Lappaconitine Sulfate Inhibits Proliferation and Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells through the Reactive Oxygen Species-Dependent Mitochondrial Pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of tumor-related deaths in the word. Lappaconitine (LA), a diterpenoid alkaloid, exerts antitumor activities. However, the effects and mechanisms of LA sulfate (LS) on HCC remain unclear. This study evaluated the activities and explored the underlying mechanisms of LS in HCC cell line HepG2 cells.

MATERIALS AND METHODS

The cell viability and proliferation were evaluated using the Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assay, respectively. The cell cycle distribution was detected by propidium iodide (PI) staining assay. The apoptosis was detected by Annexin -V-fluorescein isothiocyanate (FITC)/PI double staining assay. The cell cycle arrest and apoptosis-related proteins were estimated by western blot analysis. The mitochondrial membrane potential (MMP) was -determined through the 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimi-dazolyl carbocyanine iodide (JC-1) staining assay. The reactive oxygen species (ROS) was monitored by 20-70-dichlorofluorescein diacetate (DCFH-DA) staining assay. In vivo antitumor activities were investigated by HepG2 xenograft model.

RESULTS

Our results showed that LS significantly -inhibited the viability and proliferation of HepG2 cells. LS triggered G0/G1 cell cycle arrest, apoptosis and caspase activation. Furthermore, LS induced MMP loss and ROS accumulation. Additionally, LS suppressed the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/glycogen synthase kinase 3β (GSK3β) signaling pathway. An in vivo assay showed that LS exhibited a pronounced antitumor effect in nude mice bearing HepG2 xenografts.

CONCLUSIONS

Our results demonstrated that LS is a promising therapeutic agent for HCC directed -toward the proliferation inhibition and the induction of apoptosis.