Serum Deprivation-induced PC12 Cell Research Articles

Rearranged iridal-type triterpenoids from Iris tectorum

Three new iridal-type triterpenoids (1–3) featuring a rearranged homofarnesylside chain were isolated from the rhizomes of Iris tectorum. Compounds 2 and 3 were found to be a pair of epimers. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. A possible biosynthetic pathway for them was postulated. Moreover, the mixture of compounds 2 and 3 exhibited moderate neuroprotective activity against serum deprivation-induced PC12 cell death.

Helioscopianoids A–Q, bioactive jatrophane diterpenoid esters from Euphorbia helioscopia

The EtOH extracts of the whole plants of Euphorbia helioscopia afforded 17 new jatrophane diterpenoid esters, helioscopianoids A–Q (117), along with eight known compounds (18–25). Their structures were elucidated by extensive spectroscopic methods and Mo2(OAc)4-induced ECD analysis, and the structures of compounds 1, 2, and 7 were confirmed by X-ray crystallography. Compounds 1–17 were evaluated for inhibitory effects on P-glycoprotein (P-gp) in an adriamycin (ADM)-resistant human breast adenocarcinoma cell line (MCF-7/ADR) and neuroprotective effects against serum deprivation-induced and rotenone-induced PC12 cell damage. Compounds 8 and 16 increased the accumulation of ADM in MCF-7/ADR cells by approximately 3-fold at a concentration of 20 μmol/L. Compound 8 could attenuate rotenone-induced PC12 cell damage, and compounds 2, 8, and 12 showed neuroprotective activities against serum deprivation-induced PC12 cell damage.

Three new coumarin glycosides from the stems of Hydrangea paniculata

Three new coumarin glycosides (1-3), together with three known compounds (4-6), have been obtained from the stems of Hydrangea paniculata Sieb. Their structures were elucidated based on spectroscopic data and chemical evidence. In addition, compounds 1-3 were screened for their neuroprotective effects against serum deprivation-induced PC12 cell damage, hepatoprotective activities against DL-galactosamine-induced toxicity in HL-7702 cells and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line, but they were inactive.

4-Hydroxybenzyl-substituted glutathione derivatives from Gastrodia elata

Seven new 4-hydroxybenzyl-substituted glutathione derivatives (2–8), together with a known analogue (1), were isolated from the aqueous extract of Gastrodia elata Blume rhizomes. Their structures were determined by using spectroscopic and chemical methods. The absolute configurations of 1–8 were assigned by using Marfey's method, combined with comparing the NMR and CD spectroscopic data of sulfoxide moieties in 3–6 with those of S-(4-hydroxybenzyl)cysteine sulfoxide stereoisomers (9–12) synthesized as authentic samples. The configurations of 9–12 were confirmed by electronic CD calculations based on the quantum-mechanical time-dependent density functional theory. Furthermore, the structures of 1, 3, 5, 7, and 8 were verified by synthesis. Compound 3 was active against serum deprivation-induced PC12 cell damage and synthetic 9–14 exhibited activity against Fe2+-cysteine induced rat liver microsomal lipid peroxidation.

Coumarin Glycosides and Iridoid Glucosides with Neuroprotective Effects from Hydrangea paniculata

Five new coumarin glycosides, umbelliferone 7-O-sophoroside (1), umbelliferone 7-O-β-D-glucopyranosyl(1 → 3)-β-D-glucopyranoside (2), umbelliferone 7-O-β-D-glucopyranosyl(1 → 3)-[β-D-apiofuranosyl(1 → 6)]-β-D-glucopyranoside (3), umbelliferone 7-O-β-D-glucopyranosyl(1 → 2)-β-D-apiofuranosyl(1 → 6)-β-D-glucopyranoside (4), and umbelliferone 7-O-β-D-glucopyranosyl(1 → 5)-β-D-apiofuranosyl(1 → 6)-β-D-glucopyranoside (5), and two new iridoid glucosides, 7-O-E-isoferuloyl loganic acid (6) and 7-O-β-D-glucopyranosyl loganin (7), together with eight known compounds (8-15) were isolated from the stems of Hydrangea paniculata. Their structures were established by spectroscopic analysis and chemical methods. At 10 µM, compounds 1, 3, 5, 6, 8, 9, and 13 showed neuroprotective effects against serum deprivation-induced PC12 cell damage.

The neuroprotective effects of an extract of Gastrodia elata

Ethnopharmacological relevanceGastrodia elata (GE) Blume (family Orchidaceae) is a traditional Chinese herbal medicine for treating headaches, dizziness, tetanus, and epilepsy, indicating neuronal protective functions. Aim of the studyTo evaluate the neuroprotection of GE and its molecular mechanism in preventing serum deprivation-induced PC12 cell apoptosis. Materials and methodsAn MTT assay and Hoechst staining were used to respectively validate serum deprivation-induced cell death and apoptosis. Cyclic (c)AMP formation and protein kinase (PK)A activity were also measured after GE treatment. Western blotting was used to detect the phosphorylation of the cAMP response element-binding (CREB) protein. Transient transfection of a dominant negative CREB was used to validate the importance of CREB. ResultsGE targeted the adenosine A2A receptor (A2A-R). GE increased cAMP formation, PKA activity, and phosphorylation of the CREB protein. GE-induced CREB protein phosphorylation and protection was blocked by a PKA inhibitor and overexpression of the dominant negative CREB, respectively. ConclusionsThese results support the neuroprotective effects of GE. The protective mechanism might be mediated through an A2A-R/cAMP/PKA/CREB-dependent pathway.

Bioactive Neolignans and Lignans from the Bark of Machilus robusta

Sixteen new neolignans and lignans (1-16), together with 12 known analogues, have been isolated from an ethanol extract of the bark of Machilus robusta. Compounds 1 and 2 showed activity against HIV-1 replication in vitro, with IC(50) values of 2.52 and 2.01 μM, respectively. At 10 μM, 6, 8, and 9 reduced dl-galactosamine-induced hepatocyte (WB-F344 cells) damage, and 9 could additionally attenuate rotenone-induced PC12 cell damage. The known compounds (-)-pinoresinol (17) and (+)-lyoniresinol (18) were active against serum deprivation induced PC12 cell damage.

Lignans and Neolignans from Sinocalamus affinis and Their Absolute Configurations

Twenty-two new lignans and neolignans (1-22), together with 14 known analogues, have been isolated from an ethanolic extract of the stem (with skin removed) of Sinocalamus affinis. Their structures were elucidated by spectroscopic and chemical methods. On the basis of systematic NMR and circular dichroism (CD) data analysis, the validity of J7,8 and ΔδC8-C7 values to distinguish threo and erythro aryl glycerol units in different neolignans and the CD data [particularly the Rh2(OCOCF3)4-induced CD data (the E band)] to determine the absolute configurations at C-8 (C-7) of the aryl glycerol units are discussed. At a concentration of 10 μM, compounds 20 and 22 inhibited NO production in mouse peritoneal macrophages 84.2±5.9% and 71.7±1.0%, respectively. Compounds 19, 20, and 22 showed activity against serum deprivation induced PC12 cell damage by increasing the cell viability from 80.7±2.8% to 91.6±6.4%, 107.2±8.0%, and 97.6±8.5%, respectively.

Mechanisms of Panax ginseng in preventing rat pheochromocytoma cells from apoptosis

Aims of the study Although ginseng root possesses dominant central therapeutic effects and has recently undergone investigations for treating different neuronal diseases, most of its mechanisms are still unknown. Therefore, the neuroprotective mechanisms of ginseng were studied. Materials and methods The protection afforded by different methanol extracts of Panax ginseng (PG) was tested in a serum deprivation-induced apoptotic model using neuronal-like pheochromocytoma (PC12) cells. An MTT assay, annexin V-FITC staining, and Western blots were, respectively, applied to identify the viability of cells, the apoptotic form of cell death, and the activity of antiapoptotic signaling. Results The known antiapoptotic PI3-K/Akt and MEK/ERK pathways in this system were ruled out due to failure of LY 294002 and PD 98059 to block the protection by PG. A protein kinase A (PKA) inhibitor was found to block the protection by PG and PG-induced CREB phosphorylation, suggesting that the PKA/CREB pathway mediates the protective effect of PG. Downregulation of classical and novel PKCs failed to block the protection by PG, while an atypical PKC inhibitor blocked protection by PG. Conclusions PKA and atypical PKC are important for the protection afforded by PG in preventing serum deprivation-induced PC12 cell apoptosis.

Fermented Antrodia cinnamomea Extract Protects Rat PC12 Cells from Serum Deprivation-Induced Apoptosis: The Role of the MAPK Family†

Antrodia cinnamomea (formerly A. camphorata) has recently and commercially been used in the formulation of nutraceuticals and functional foods in Taiwan. Because of its diverse properties, the neuroprotective effect was investigated using a fermented A. cinnamomea extract in this study. Serum deprivation-induced apoptosis in neuronal-like pheochromocytoma (PC12) cells was used as a cell stress model, and it was found that A. cinnamomea was effective in preventing serum-deprived apoptosis according to results of an MTT assay and Hoechst staining. Serum deprivation resulted in decreased phosphorylation of extracellular signal-regulated kinase (ERK) and increased phosphorylations of c-Jun NH2-terminal kinase (JNK) and p38, of the family of mitogen-activated protein kinases (MAPKs); however, A. cinnamomea reversed these phenomena, supporting the antagonistic effects between ERK and JNK-p38 in regulating cell survival. The previously identified active component of A. cinnamomea, adenosine (ADO), also exerted the same effects as A. cinnamomea in preventing apoptosis and regulating phosphorylations of MAPKs. Although an inhibitor of the ERK upstream activator blocked A. cinnamomea-induced ERK phosphorylations, it failed to block the protection of A. cinnamomea and ADO. A protein kinase A (PKA) inhibitor blocked the protection by both A. cinnamomea and ADO. Both JNK and p38 inhibitors were effective in preventing the phosphorylations of JNK and p38 and serum deprivation-induced apoptosis. Collectively, A. cinnamomea prevented serum deprivation-induced PC12 cell apoptosis through a PKA-dependent pathway and by suppression of JNK and p38 activities.

Ligusticum chuanxiong prevents rat pheochromocytoma cells from serum deprivation-induced apoptosis through a protein kinase A-dependent pathway

Ligusticum chuanxiong (LC) is a traditional Chinese herbal medicine used to treat various cardiovascular diseases. In this study, the butanol extract of LC was found to protect neuronal-like pheochromocytoma cells from serum deprivation-induced apoptosis. Both a serine/threonine kinase inhibitor and a specific protein kinase A (PKA) inhibitor blocked the protective effect of LC. A transcription inhibitor (actinomycin D) and a protein synthesis inhibitor (cyclohexamide) also attenuated the protective effect of LC, suggesting the requirement of gene expression for the protection of LC. On the other hand, LC increased both the formation of cyclic-AMP and the phosphorylation of the cyclic-AMP response element-binding protein (CREB), a downstream target of PKA and a nuclear transcription factor known for neuroprotective mechanism. Furthermore, LC-induced CREB phosphorylation and protective effect could be blocked by a PKA inhibitor and overexpression of the dominant negative CREB, respectively. Taken together, the protective mechanism of LC in antagonizing serum deprivation-induced PC12 cell apoptosis might be mediated through a PKA/CREB-dependent pathway.

Adenosine as an active component of Antrodia cinnamomea that prevents rat PC12 cells from serum deprivation-induced apoptosis through the activation of adenosine A 2A receptors

Antrodia cinnamomea (formerly named Antrodia camphorata) is a rare medicinal fungus. We previously reported that it exhibits antioxidative, vasorelaxative, anti-inflammatory, and anti-angiogenic effects. When serum deprivation-induced apoptosis in neuronal-like PC12 cells was used as a stress model, the extract of A. cinnamomea displayed effectiveness in preventing serum-deprived apoptosis. Since our previous data show that the extract of A. cinnamomea contains adenosine (ADO), we attempt to investigate if the active component is ADO and to identify its targeting site in this study. After pre-incubation with ADO deaminase, neither ADO nor the extract of A. cinnamomea exerted any protection, demonstrating that the active component of A. cinnamomea is ADO. Furthermore, an ADO A 2A receptor (A 2A-R) antagonist was used and was able to block the protective effects of ADO and the extract of A. cinnamomea, demonstrating that the ADO targeting site in this model is A 2A-R. Taken together, the protective effect of A. cinnamomea is owed to its active component, ADO, which acts through activation of A 2A-R to prevent serum deprivation-induced PC12 cell apoptosis.

Antrodia camphorata prevents rat pheochromocytoma cells from serum deprivation-induced apoptosis

Antrodia camphorata ( A. camphorata) is a rare medicinal fungus with antioxidative, vasorelaxtative, anti-inflammatory and anti-hepatitive effects. However, the neuroprotective effect has not been studied. By using serum deprivation-induced apoptosis in neuronal-like PC12 cells as a cell stress model, we found that A. camphorata is effective in preventing serum-deprived apoptosis. Inhibitors of both a serine/threonine kinase and a specific protein kinase A (PKA) inhibited the protective effect of A. camphorata, indicating that A. camphorata prevents serum-deprived PC12 cell apoptosis through a PKA-dependent mechanism. A transcription inhibitor, actinomycin D, and a protein synthesis inhibitor, cyclohexamide, both attenuated the protective effect of A. camphorata, indicating a requirement for gene expression for protection by A. camphorata. On the other hand, A. camphorata also increased phosphorylated CREB, a transcription factor, which is H-89-inhibitable in this study, suggesting the possibility that A. camphorata prevents serum deprivation-induced PC12 cell apoptosis through a PKA/CREB-dependent pathway.