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There is increasing evidence that starvation induces autophagy, which may be protective during starvation, in an AMPK-dependent manner. Polysaccharides from Fuzi (FPS) reportedly have protective effects on nutrition-limited livers. The present study was designed to determine whether FPS protected H9c2 cells against starvation-induced cytotoxicity using an AMPK/mTOR-dependent mechanism. H9c2 cells were incubated in serum and glucose starvation media for 12 hours to establish a cell injury model. 3-Methyladenine (3MA, an autophagy inhibitor) was used to identify the exact role of autophagy in starvation. Cells were incubated with different FPS concentrations, and the cell injury levels, autophagy activity and AMPK/mTOR phosphorylation were measured. Adenine 9-β-D-arabinofuranoside (Ara-A, an AMPK inhibitor) and 5-amino-4-imidazole-carboxamide riboside (AICAR, an AMPK activator) were used to identify whether the AMPK/mTOR pathway was involved in FPS-mediated cardioprotection. We demonstrated that starvation decreased cell viability in a time-dependent manner, and 3MA-induced autophagy inhibition aggravated the reduced cell viability. FPS treatment attenuated the cell viability decrement and the starvation-induced decline in the mitochondrial membrane potential (MMP), and autophagy; also, the AMPK/mTOR pathways were activated during treatment. Ara-A treatment abolished the protective effect of FPS, while AICAR treatment had a similar effect to FPS. We conclude that autophagy attenuates starvation-induced cardiomyocyte death, and FPS increases autophagy activity to protect against starvation-induced cytotoxicity in H9c2 cells, likely through AMPK/mTOR pathway activation.
Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma Curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Herein, we systematically investigated the effects of FUR on the significant processes of tumor progression with the relatively low concentrations in 95-D lung cancer cells. FUR concentration-dependently inhibited cell proliferation and blocked the cell cycle progressions in G1 phase by down-regulating the protein levels of cyclin D1 and CDK6, and up-regulating those of p21 and p27 in 95-D cells. FUR also affected the signaling molecules that regulate apoptosis in 95-D cells revealed by the down-regulation of the protein levels of full PARP, pro-caspase-7, survivin, and Bcl-2, and the up-regulation of cleaved PARP. Further studies showed that FUR enhanced the expression of light chain 3-II (LC3-II) in the protein level, indicating that autophagy is involved in this process. Besides, the adhesion ability of 95-D cells to matrigel and fibronectin was slightly inhibited after FUR treatment for 1 h in our experimental condition. FUR also slightly suppressed cell migration and invasion in 95-D cells according to the data from wound healing and Transwell assays, respectively. Taken together, FUR activated the signal molecules regulating G1 cell cycle arrest, apoptosis and autophagy, while slightly affecting the key steps of cell metastasis in 95-D lung cancer cells in the relatively low concentrations.
α-Phellandrene (α-PA) is a cyclic monoterpene. To investigate the induction of autophagy by α-PA and its mechanism, human liver tumor cells (J5) were incubated with α-PA and analyzed for cell viability and the molecular regulation of pre-autophagosome origination and autophagosome formation. According to the results, PI3K-I, mTOR, and Akt protein levels were decreased after α-PA treatment compared to those of the control group (p < 0.05). The phosphorylation of Bcl-2, and PI3K-III, LC3-II and Beclin-1 protein levels in J5 cells were increased after α-PA treatment (p < 0.05). In addition, α-PA up-regulated nuclear p53 and down-regulated cytoplasmic p53 expression in J5 cells. The NF-κB pathway was activated, as indicated by increase in cytosolic phosphorylated IκB, nuclear NF-κB levels, and the DNA-binding activity of NF-κB after α-PA treatment in J5 cells (p < 0.05). These results suggest that α-PA can induce J5 cell autophagy by regulating mTOR and LC-3II expression, p53 signaling, and NF-κB activation in J5 cells.
For centuries, natural plant extracts have played an important role in traditional medicine for curing and preventing diseases. Studies have revealed that Artocarpus communis possess various bioactivities, such as anti-inflammation, anti-oxidant, and anticancer activities. A. communis offers economic value as a source of edible fruit, yields timber, and is widely used in folk medicines. However, little is known about its molecular mechanisms of anticancer activity. Here, we demonstrate the antiproliferative activity of A. communis methanol extract (AM) and its dichloromethane fraction (AD) in two human hepatocellular carcinoma (HCC) cell lines, HepG2 and PLC/PRF/5. Colony assay showed the long-term inhibitory effect of both extracts on cell growth. DNA laddering and immunoblotting analyses revealed that both extracts did not induce apoptosis in the hepatoma cell lines. AM and AD-treated cells demonstrated different cell cycle distribution compared to UV-treated cells, which presented apoptotic cell death with high sub-G1 ratio. Instead, acridine orange staining revealed that AM and AD triggered autophagosome accumulation. Immunoblotting showed a significant expression of autophagy-related proteins, which indicated the autophagic cell death (ACD) of hepatoma cell lines. This study therefore demonstrates that A. communis AM and its dichloromethane fraction can induce ACD in HCC cells and elucidates the potential of A. communis extracts for development as anti tumor therapeutic agents that utilize autophagy as mechanism in mediating cancer cell death.
Tanshinones are a group of bioactive constituents isolated from Salvia miltiorrhiza Bunge, a widely prescribed traditional Chinese herb. In the current study, the anticancer properties of total tanshinones (TDT) were evaluated using 95D lung cancer cells. Tanshinone IIA was identified as the main component of TDT. Compared with tanshinone IIA, TDT showed more cytotoxic effects on the 95D cells. Annexin V/7-AAD double staining, the depolarization of mitochondrial membrane potential (MMP) (Δψ), the up-regulation of pro-apoptotic proteins, such as cleaved-PARP, cleaved-caspase-3, Bax, and Bad, and the down-regulation of anti-apoptotic protein Bcl-2 were evidence of TDT-induced apoptosis. Furthermore, TDT-induced autophagy as demonstrated by monodansylcadaverine (MDC) staining and the up-regulation of autophagy-associated proteins, such as LC3-II, Beclin-1, Atg3, Atg5, Atg7, and Atg12. Autophagy inhibitors, 3-methyladenine (3-MA) and bafilomycin A1, enhanced TDT-induced cell death. 3-MA pretreatment enhanced the TDT-induced up-regulation of Bax and cleaved-PARP. In addition, TDT induced the generation of reactive oxygen species (ROS), which was reversed by N-acetylcysteine (NAC). NAC also reversed TDT-induced depolarization of Δψ, MDC staining, up-regulation of Bax, cleaved-PARP, Beclin-1, LC3-II, and cell viability. In conclusion, our findings showed that TDT-induced apoptosis and protective autophagy in 95D cells mediated by increasing intracellular ROS production.
Crocin, the main effective component of saffron, exerts protective effects against ischemia/reperfusion injury during strokes. However, the effects of crocin in myocardial ischemia/reperfusion injury, and the mechanisms involved, remain unknown. Pretreated with crocin for 7 days, C57BL/6N mice were subjected to 30 min of myocardial ischemia followed by 12h of reperfusion (for cardiac function and infarct size, cell apoptosis and necrosis). Neonatal mouse cardiomyocytes were subjected to 2 h of hypoxia followed by 4 h of reoxygenation. NMCM’s survival was assessed during hypoxia and reoxygenation in the presence or absence of the autophagy inhibitor 3-methyladenine or the inducer rapamycin. Western blotting was used to evaluate AMPK, Akt, and autophagy-related proteins. Autophagosome was observed using electron microscopy. In the in vivo experiment, crocin pretreatment significantly attenuated infarct size, myocardial apoptosis and necrosis, and improved left ventricular function following ischemia/reperfusion. In vitro data revealed that autophagy was induced during hypoxia, the levels of which were intensely elevated during reoxygenation. Crocin significantly promoted autophagy during ischemia, accompanied with the activation of AMPK. In contrast, crocin overtly inhibited autophagy during reperfusion, accompanied with Akt activation. Induction and inhibition of autophagy mitigated crocin induced protection against NMCMs injury during hypoxia and reoxygenation, respectively. Our data suggest that crocin demonstrated a myocardial protective effect via AMPK/mTOR and Akt/mTOR regulated autophagy against ischemia and reperfusion injury, respectively.
Alcoholic fatty liver (AFL) is early stage of alcoholic liver disease, which can progress to steatohepatitis, fibrosis, and cirrhosis if alcohol consumption is continued. The pathogenesis of AFL is associated with excessive lipid accumulation in hepatocytes. Resveratrol (RES), a dietary polyphenol found in red wines and grapes, has been shown to have a hepatoprotective effect. Autophagy is a crucial physiological process in cellular catabolism that involves the regulation of lipid droplets. Autophagy maintains a balance between protein synthesis, degradation and self-recycling. In the present study, we evaluated the protective effects of RES (10mg/kg, 30mg/kg, 100mg/kg) on AFL mice fed with an ethanol Lieber-DeCarli liquid diet, and HepG2 cells in the presence of oleic acid and alcohol to investigate whether resveratrol could induce autophagy to attenuate lipid accumulation. The results showed that RES (30mg/kg and 100mg/kg) treatment significantly attenuated hepatic steatosis and lowered the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), low density lipoprotein cholesterol (LDL-C). H&E staining showed that RES reduced hepatic lipid accumulation. Transmission electron microscopy (TEM) images showed that RES treatment increased the number of autophagosomes and promoted the formation of autophagy. Western blot analysis showed that RES treatment increased the levels of microtubule-associated protein light chain3- II (LC3-II) and Beclin1, decreased expression of p62 protein. In addition, in vitro studies also demonstrated that RES led to the formation of acidic vesicular organelles (AVOs), however, 3-Methyladenine (3-MA), a specific inhibitor of autophagy, obviously inhibited the above effects of RES. In conclusion, RES has protective effects on alcoholic hepatic steatosis, and the potential mechanism might be involved in inducing autophagy.
Autophagy exists in vascular endothelial cells, but the relationship between autophagy and blood vessel dysfunction in hypertension remains elusive. This study aimed to investigate role of autophagy in vascular endothelial dysfunction in prehypertension and hypertension and the underlying mechanisms involved. Furthermore, we sought to determine if and how tetrahydroxystilbene glucoside (TSG), a resveratrol analogue and active ingredient of Polygonum multiflorum Thunb used for its cardiovascular protective properties in traditional Chinese medicine, influences vascular endothelial function. Male spontaneously hypertensive rats (SHRs) aged 4 weeks (young) and 12 weeks (adult) were studied and the vascular function of isolated aorta and mesenteric artery was assessed in vitro. Compared with Wistar Kyoto rats (WKY), young and adult SHRs showed endothelial dysfunction of the aorta and mesenteric artery, along with decreased pAkt, pmTOR, and autophagic marker protein p62 and increased LC3 II/I in microvascular but not aortic tissues. TSG administration for 14 days significantly improved mesenteric vascular endothelial function, increased levels of pAkt and pmTOR, and decreased autophagy. Pretreatment of young SHRs with the mTOR inhibitor rapamycin blocked the antiautophagic and vasodilative effects of TSG. Moreover, TSG significantly activated Akt-mTOR signaling in HUVECs and reduced the autophagic levels in vitro, which were almost completely blocked by rapamycin. In summary, mesenteric endothelial dysfunction in prehypertensive SHRs was at least partly attributable to excessive autophagy in vascular tissues. TSG partly restored microvascular endothelial dysfunction through activating the Akt/mTOR pathway, which consequently suppressed autophagy, indicating that TSG could be potentially applied to protect vascular function against subclinical changes in prehypertension.
Baicalein (BA), one of the major compounds isolated from the root of Scutellaria baicalensis Gerogi, exhibits various pharmacological effects, such as anti-oxidant, anti-inflammatory, and anticancer effects. In this study, we found that BA reduced cell viability and increased apoptosis in ovarian cancer cells. Treatment of cells with BA enhanced microtubule-associated protein light chain 3-II (LC3-II) expression, acidic vesicular organelle and GFP-LC3 fluorescence dot accumulation. Combined treatment with chloroquine and BA apparently reduced cell viability and increased the cleavage of poly (ADPribose) polymerase (PARP) in both HEY and A2780 ovarian cancer cell lines, indicating that BA induces a protective autophagy in these cells. Knockdown of Beclin 1 by siRNA remarkably decreased BA-induced LC3-II lipidation. In addition, we found an increase in the phosphorylation of extracellular signal-regulated kinase (ERK, Thr202/Thr204) and AKT (Ser473) after BA treatment, and inhibition of ERK activation by the pharmacological inhibitor U0126 or ERK siRNA blocked BA-induced autophagy. Taken together, these results suggest that BA induces Beclin 1- and ERK-dependent autophagy in ovarian cancer cells.
Abstract: Eucommia ulmoides Oliv. is a famous traditional Chinese medicine which exhibits anti-oxidative stress ability and neuro-protective effects. Aucubin is the predominant component of Eucommia ulmoides Oliv. Our present study is intended to investigate aucubin’s potential protective effects on neurons against epilepsy in the hippocampus by establishing the lithium-pilocarpine induced status epilepticus (SE) rat model in vivo. Aucubin (at a low dose and a high dose of 5mg/kg and 10mg/kg, respectively) was administered through gavage for two weeks before lithium-pilocarpine injection. Rats were sacrificed at 4, 24 and 72h after SE induction. Pretreatment with both low-dose and high-dose aucubin significantly reduced the number of death neurons (p<0.05) and increased the number of surviving neurons (p<0.05) in DG, Hilus, CA1 and CA3 hippocampal regions post SE. Meanwhile, it significantly inhibited necroptosis proteins (MLKL and RIP-1) (p<0.05 or p<0.01) and enhanced autophagy protein (Beclin-1 and LC3BII/LC3BI) prevalence in the hippocampus (p<0.05 or p<0.01). In conclusion, aucubin appeared to ameliorate damages in lithium-pilocarpine induced SE in hippocampus, reduce the number of apoptotic neurons, and increased the number of survival neurons by inducing autophagy and inhibiting necroptosis. These original findings might provide an important basis for the further investigation of the therapeutic role of aucubin in treatment or prevention of epilepsy-related neuronal damages.
Autophagy refers to the process in which the cellular lysosome degrades the cell’s own damaged organelles and related macromolecule substances. It plays important roles in the homeostasis of organs, cell survival, and stable development. Previous studies indicate that the process of cardiopathology is closely associated with autophagy and some of Chinese medicines (active compounds and formulae) are found to have beneficial effects on injured cardiomyocytes via the modulation of autophagy. This review highlights the efficacy of the action of Chinese medicine on the regulation of myocardial autophagy and summarizes the related molecular and signal mechanisms. Our study discovers that some active compounds and formulae of Chinese medicines react on the specific targets of autophagy in related signal pathways to exert protective effects in the processes of ischemia and reperfusion, as well as, in other cardiopathological models. Parts of these compounds even have the characteristics of multiple targets in autophagic signal pathways and dual-directional regulated actions on autophagy, suggesting that Chinese medicines, which possess the ability to modulate autophagy, might improve effective cardio protection in the treatment of cardiovascular disease.
Lutein is a carotenoid with anti-oxidant properties. Autophagy, an evolutionarily conserved catabolic cellular pathway for coping with stress conditions, is responsive to reactive oxygen species (ROS) and degrades damaged organelles. We previously demonstrated that lutein can induce anti-oxidant enzymes to relieve methotrexate-induced ROS stress. We therefore hypothesized that lutein, which activates ROS-scavenging enzymes, can also induce autophagy for cell survival. In this study, we demonstrated that lutein treatment attenuated the reduction in cell viability caused by H2O2. Lutein dose-dependently induced the processing of microtubule-associated protein light chain 3 (LC3)-II, an autophagy marker protein, and accumulation of LC3-positive puncta in rat intestinal IEC-6 cells. Furthermore, (a) direct observation of autophagosome formation through transmission electron microscopy, (b) upregulation of autophagy-related genes including ATG4A, ATG5, ATG7, ATG12, and beclin-1 (BENC1), and (c) increased BECN1/Bcl-2 ratio confirmed the induction of autophagy by lutein. The results revealed that bafilomycin-A1-induced inhibition of autophagy reduced cell viability and increased apoptosis in lutein-treated cells, indicating a protective role of lutein-induced autophagy. Lutein treatment also activated adenosine monophosphate–activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK), and p-38, but had no effects on the induction of extracellular signal-related kinase or inhibition of mTOR; however, the inhibition of activated AMPK, JNK, or p-38 did not attenuate lutein-induced autophagy. Finally, increased BECN1 expression levels were detected in lutein-treated cells, and BECN1 knockdown abolished autophagy induction. These results suggest that lutein-induced autophagy was mediated by the upregulation of BECN1 in IEC-6 cells. We are the first to demonstrate that lutein induces autophagy. Elevated autophagy in lutein-treated IEC-6 cells may have a protective role against various stresses, and this warrants further investigation.
Autophagy is an evolutionarily conserved degradation process which eliminates dysfunctional proteins and cytoplasmic components to maintain homeostasis for cell survival. Increasing evidence has demonstrated the modulatory role of autophagy in ischemic heart diseases (IHDs). Traditionally, this process has been recognized as having protective functions, such as inhibiting atherosclerosis progression and reducing cell death during the ischemic phase. However, recent studies have suggested its dual roles in myocardial ischemia/reperfusion (MIR) injury. Excessive autophagy may play a deleterious role in cardiac function, due to overwhelming clearance of cellular constituents and proteins. Hence modulation of autophagy to increase cardiomyocyte survival and improve cardiac function is meaningful for the treatment of IHD. Chinese herbal medicine, including extractive compounds and patented drugs, has shown its potential role in treating IHD by addressing autophagy-related mechanisms. This review summarizes the updated knowledge on the molecular basis and modulatory role of autophagy in IHD and the recent progress of Chinese herbal medicine in its treatment.
Carnosol is an anti-oxidant and anti-inflammatory compound from rosemary. In this paper, we investigated antitumor activity of carnosol against human osteosarcoma cells. We found the viability of human osteosarcoma MG-63 cells was significantly decreased in the presence of carnosol (cell viabilities: 17.2% for 20μg/ml of CS vs. 100% for control, p<0.05). Carnosol induced apoptosis and cell cycle arrest in a dose-dependent manner in MG-63 cells. Furthermore, carnosol exposure increased the levels of reactive oxygen species (ROS). The pre-treatment of NAC, the ROS scavenger, blocked the inhibition of cell viability in the carnosol treatment, indicating that ROS is important in the antiproliferation effect. Moreover, we demonstrated that carnosol significantly induced autophagy and co-administration of autophagy inhibitor reduced the antiproliferating effect of carnosol. This result exhibited the cytotoxic effect of autophagy induced by carnosol in MG-63 cells. Interestingly, the treatment of NAC decreased carnosol-induced autophagy. Collectively, these data indicate that carnosol suppresses the viability of human osteosarcoma MG-63 cells by upregulation of apoptosis and autophagy, which are both mediated by ROS. Thus, carnosol might serve as a potential therapeutic agent against osteosarcoma.
Curcumin is a hydrophobic polyphenol derived from turmeric: the rhizome of the herb Curcumalonga. Autophagy is an evolutionarily conserved process, in which cellular proteins and organelles are engulfed in autophagosome and then fuses with lysosome for degradation. Our previous study showed that Curcumin activates lysosome and induce autophagy through inhibition of AKT (protein kinase K, PKB)-mammalian target of rapamycin (mTOR) pathway. But whether Curucmin affects the fusion of autophagosome-lysosome is still not clear. Here, we used Curcumin-probe conjugation with an alkyne moiety to label mouse embryonic fibroblasts (MEFs) and found that Curcumin targets autophagy-related proteins, enhances autophagic flux and activates lysosome in cells. Moreover, Curcumin treatment promotes the fusion of autophasosome-lysosome in MEFs. Second, the enhanced fusion of autophagosome-lysosome is attributed to mTOR suppression. Third, blockage of the autophagosome-lysosome fusion leads to cell growth inhibition by Curcumin. Taken together, data from our study indicates the importance of the fusion of autophagosome-lysosome in Curcumin-induced autophagy, which may facilitate the development of Curcumin as a potential therapeutic agent for oxidative stress-related diseases.
Numerous studies support the use of herbal medicine or natural products for chemotherapy in human cancers. Reports have associated curcumin (CUR), dimethoxy curcumin (DMC) and bisdemethoxycurcumin (BDMC) with numerous biological activities including anticancer activities, but no available information have shown that these induced apoptotic cell death and autophagy in human oral cancer cells. In the present study, we investigated the effect of CUR, DMC and BDMC on the cell viability, apoptotic cell death, reactive oxygen species (ROS), Ca2+, mitochondria membrane potential (MMP) and caspase activities using flow cytometry assay and autophagy by monodansylcadaverine (MDC) and acridine orange (AO) staining in human oral cancer SAS cells. Results indicated that CUR, DMC and BDMC decreased total viable cell number through the induction of cell autophagy and apoptosis in SAS cells. Cells were pretreated with N-acetyl-cysteine (NAC), 3-methyladenine (3MA), rapamycin and carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoro-methylketone (Z-VAD-fmk) and then were treated with CUR, DMC and BDMC that led to increased total viable cell number when compared to CUR, DMC and BDMC treatments only. Results indicated induced apoptotic cell death through ROS, mitochondria-dependent pathway and induction of cell autophagy. Based on those observations, we suggest that CUR, DMC and BDMC could be used as a potential anticancer agent in human oral cancer.
Intervertebral disc degeneration (IDD) is a major cause of lower back pain, but few efficacious medicines have been developed for IDD. Increased nucleus pulposus cells apoptosis is a dominant pathogenesis of IDD and is considered a therapeutic target. Previously, our group proved that autophagy may protect nucleus pulposus cells against apoptosis. As one of the major bioflavonoids of citrus, naringin activates autophagy. Therefore, we hypothesize that naringin may have therapeutic potential for IDD by activating autophagy in nucleus pulposus cells. In this study, we evaluated the effects of naringin on TBHP-induced oxidative stress in nucleus pulposus cells in vitro as well as in puncture-induced rat IDD model in vivo. Our results showed that naringin could reduce the incidence of oxidative stress-induced apoptosis in nucleus pulposus cells and promoted the expression of autophagy markers LC3-II/I and beclin-1. Meanwhile, inhibition of autophagy by 3-MA may partially reverse the anti-apoptotic effect of naringin, indicating that autophagy was involved in the protective effect of naringin in nucleus pulposus cells. Further study showed that autophagy regulation of naringin may be related to AMPK signaling. Also, we found that naringin treatment can regulate the expression of collagen II, aggrecan and Mmp13 to sustain the extracellular matrix. Furthermore, our in vivo study showed that naringin can ameliorate IDD in puncture-induced rat model. In conclusion, our study suggests that naringin can protect nucleus pulposus cells against apoptosis and ameliorate IDD in vivo, the mechanism may relate to its autophagy regulation.
Allyl isothiocyanate (AITC), one of the most widely studied phytochemicals, inhibits the survival of human prostate cancer cells while minimally affecting normal prostate epithelial cells. Our study demonstrates the mechanism of AITC-induced cell death in prostate cancer cells. AITC induces autophagy in RV1 and PC3 cells, judging from the increased level of LC3-II protein in a dose- and time-dependent manner, but not in the normal prostate epithelial cell (PrEC). Inhibition of autophagy in AITC-treated cells decreased cell viability and enhanced apoptosis, suggesting that the autophagy played a protective role. There are several pathways activated in ATIC-treated cells. We detected the phosphorylation forms of mTOR, ERK, AMPK, JNK and p38, and ERK AMPK and JNK activation were also detected. However, inhibition of AITC-activated ERK, AMPK and JNK by pre-treatment of specific inhibitors did not alter autophagy induction. Finally, increased beclin-1 expression was detected in AITC-treated cells, and inhibition of AITC-induced beclin-1 attanuated autophagy induction, indicating that AITC-induced autophagy occurs through upregulating beclin-1. Overall, our data show for the first time that AITC induces protective autophagy in Rv1 and PC3 cells through upregulation of beclin-1. Our results could potentially contribute to a therapeutic application of AITC in prostate cancer patients.
This study assessed the anti-apoptotic effects of the administration of ferulic acid (FrA) in rats 30min before middle cerebral artery occlusion (MCAo) followed by 3 d of ischemia and the involvement of 70kDa heat shock protein (HSP70)-mediated signaling in the penumbral cortex. Our results demonstrated that FrA pretreatment at doses of 80mg/kg (FrA-80mg) and 100mg/kg (FrA-100mg) effectively ameliorated neurological functions and reduced the numbers of cytochrome c-, cleaved caspase-3-, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells in the penumbral cortex 3 d after ischemia. Moreover, FrA-80mg and FrA-100mg pretreatment markedly upregulated cytosolic HSP70, Beclin-1, microtubule-associated protein 1 light chain 3 (LC3) A/B-II and autophagy-related protein 5 (Atg5) expression; cytosolic and mitochondrial X-linked inhibitor of apoptosis (XIAP) expression and the Bcl-2/Bax ratio. FrA pretreatment downregulated cytosolic cytochrome c, apoptosis-inducing factor (AIF), procathepsin B, and cathepsin B expression and mitochondrial and cytosolic second mitochondria-derived activator of caspase/direct inhibitor of apoptosis protein-binding protein with a low isoelectric point (Smac/DIABLO) expression in the penumbral cortex. Pretreatment with VER155008, a HSP70 family inhibitor, significantly inhibited the effects of FrA-100mg on the expression of the aforementioned proteins expression in the penumbral cortex. FrA-80mg and FrA-100mg pretreatment exerts neuroprotective effects against caspase-dependent and -independent apoptosis through activating HSP70/Bcl-2- and HSP70/autophagy-induced signaling pathways. Furthermore, the HSP70/Bcl-2- and HSP70/autophagy-induced anti-apoptotic effects of FrA pretreatment can be attributed to the regulation of Bax/cytochrome c/Smac/DIABLO/XIAP/ caspase-3- (or Bax/AIF-) and Beclin-1/LC3A/B-II/Atg5-mediated signaling, respectively, in the penumbral cortex 3 d after permanent MCAo.
Scutellaria Radix (SR) is an herb traditionally used in Asian countries to treat inflammatory diseases. Recent studies report that SR exhibits anticancer activities in various types of tumors. In this study, we investigated the apoptotic and autophagic effect of SR in non-small cell lung cancer (NSCLC), the leading cause of cancer-associated death. Treatment of SR in two NSCLC cell lines, H358 and H2087 cells resulted in suppressed cell viability. Western blot assays showed increased expressions of Bcl-2-associated X protein (Bax), cleaved-caspase 3 and cleaved-Poly ADP ribose polymerase (PARP), key factors of apoptosis. Co-treatment of SR with a caspase inhibitor Z-VAD led to nullification of the antiproliferative effect, suggesting the role of apoptosis in the action mechanism of SR. Further experiments revealed autophagy was involved in the effect of SR. SR-treated NSCLC cells expressed increased ratio of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II/LC3-I. When chloroquine was co-treated with SR, this ratio was further increased, indicating SR treatment induced autophagy in NSCLC cells. Interestingly, loss of autophagy by 3-Methyladenine (3-MA) co-treatment suppressed SR-induced apoptosis. We then evaluated the relevance of AMP-activated protein kinase (AMPK) in the autophagic/apoptotic process in NSCLC by SR treatment. Immunoblot assays showed increased phosphorylation of AMPKα and P70-S6 kinase in SR-treated H358 and H2087 cells. Under AMPK-inhibited conditions by compound C, SR treatment failed to induce both autophagy and apoptosis. Taken together, this study identifies the positive effect of SR in H358 and H2087 cells by inducing apoptosis via AMPK-dependent autophagy. Thus, our results suggest the potential use of SR as a novel therapeutic strategy for NSCLC patients.