The Biosynthetic Gene Cluster of Mushroom-Derived Antrocin Encodes Two Dual-Functional Haloacid Dehalogenase-like Terpene Cyclases.

(-)-Antrocin (1), produced by the medicinal mushroom Antrodia cinnamomea, is a potent antiproliferative compound. The biosynthetic gene cluster of 1 was identified, and the pathway was characterized by heterologous expression. We characterized a haloacid dehalogenase-like terpene cyclase AncC that biosynthesizes the drimane-type sesquiterpene (+)-albicanol (2) from farnesyl pyrophosphate (FPP). Biochemical characterization of AncC, including kinetic studies and mutagenesis, demonstrated the functions of two domains: a terpene cyclase (TC) and a pyrophosphatase (PPase). The TC domain first cyclizes FPP to albicanyl pyrophosphate, and the PPase domain then removes the pyrophosphate to form 2. Intriguingly, AncA (94 % sequence identity to AncC), in the same gene cluster, converts FPP into (R)-trans-γ-monocyclofarnesol instead of 2. Notably, Y283/F375 in the TC domain of AncA serve as a gatekeeper in controlling the formation of a cyclofarnesoid rather than a drimane-type scaffold.

Synthetic 4-Hydroxy Auxarconjugatin B, a Novel Autophagy Inducer, Attenuates Gouty Inflammation by Inhibiting the NLRP3 Inflammasome.

Gouty arthritis results from the generation of uric acid crystals within the joints. These uric acid crystals activate the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, which is involved in chronic inflammatory diseases, including gouty arthritis. This study identified the polyenylpyrrole derivative 4-hydroxy auxarconjugatin B (4-HAB), a novel autophagy inducer, which attenuated uric acid crystals-mediated activation of the NLRP3 inflammasome in vitro and in vivo. 4-HAB dose-dependently reduced the release of interleukin (IL)-1ß, IL-18, active caspase-1 and apoptosis-associated speck-like protein (ASC) in uric acid crystals-activated macrophages. In a mechanistic study, 4-HAB was shown to inhibit uric acid crystals-induced mitochondrial damage, lysosomal rupture and ASC oligomerization. Additionally, 4-HAB inhibited the NLRP3 inflammasome through Sirt1-dependent autophagy induction. Furthermore, the anti-inflammatory properties of 4-HAB were confirmed in a mouse model of uric acid crystals-mediated peritonitis by the reduced levels of neutrophil influx, IL-1ß, active caspase-1, IL-6 and MCP-1 in lavage fluids. In conclusion, 4-HAB attenuates gouty inflammation, in part by attenuating activation of the NLRP3 inflammasome through the Sirt1/autophagy induction pathway.

Glucosamine inhibits IL-1ß expression by preserving mitochondrial integrity and disrupting assembly of the NLRP3 inflammasome.

The NLRP3 inflammasome promotes the pathogenesis of metabolic, neurodegenerative and infectious diseases. Increasing evidences show that the NLRP3 inflammasome is a promising therapeutic target in inflammatory diseases. Glucosamine is widely used as a dietary supplement to promote the health of cartilage tissue and is expected to exert anti-inflammatory activity in joint inflammation, which is a nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome-associated complication. Here, we investigated whether GlcN inhibits the NLRP3 inflammasome and dissected the underlying molecular mechanisms. We found that GlcN suppressed the NLRP3 inflammasome in mouse and human macrophages. A mechanistic study revealed that GlcN inhibited the expression of NLRP3 and IL-1ß precursor by reducing reactive oxygen species generation and NF-κB activation in lipopolysaccharide-activated macrophages. GlcN also suppressed mitochondrial reactive oxygen species generation and mitochondrial integrity loss in NLRP3-activated macrophages. Additionally, GlcN disrupted NLRP3 inflammasome assembly by inhibiting NLRP3 binding to PKR, NEK7 and ASC. Furthermore, oral administration of GlcN reduced peritoneal neutrophils influx and lavage fluids concentrations of IL-1ß, IL-6 MCP-1 and TNF-α in uric acid crystal-injected mice. These results indicated that GlcN might be a novel dietary supplement for the amelioration of NLRP3 inflammasome-associated complications.

Mechanistic insight into the attenuation of gouty inflammation by Taiwanese green propolis via inhibition of the NLRP3 inflammasome.

Dysregulation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is involved in many chronic inflammatory diseases, including gouty arthritis. Activation of the NLRP3 inflammasome requires priming and activation signals: the priming signal controls the expression of NLRP3 and interleukin (IL)-1ß precursor (proIL-1ß), while the activation signal leads to the assembly of the NLRP3 inflammasome and to caspase-1 activation. Here, we reported the effects of the alcoholic extract of Taiwanese green propolis (TGP) on the NLRP3 inflammasome in vitro and in vivo. TGP inhibited proIL-1ß expression by reducing nuclear factor kappa B activation and reactive oxygen species (ROS) production in lipopolysaccharide-activated macrophages. Additionally, TGP also suppressed the activation signal by reducing mitochondrial damage, ROS production, lysosomal rupture, c-Jun N-terminal kinases 1/2 phosphorylation and apoptosis-associated speck-like protein oligomerization. Furthermore, we found that TGP inhibited the NLRP3 inflammasome partially via autophagy induction. In the in vivo mouse model of uric acid crystal-induced peritonitis, TGP attenuated the peritoneal recruitment of neutrophils, and the levels of IL-1ß, active caspase-1, IL-6 and monocyte chemoattractant protein-1 in lavage fluids. As a proof of principle, in this study, we purified a known compound, propolin G, from TGP and identified this compound as a potential inhibitor of the NLRP3 inflammasome. Our results indicated that TGP might be useful for ameliorating gouty inflammation via inhibition of the NLRP3 inflammasome.

Ergosterol peroxide from marine fungus Phoma sp. induces ROS-dependent apoptosis and autophagy in human lung adenocarcinoma cells.

As part of our ongoing search for novel therapeutic structures from microorganism, the chemical examination of marine fungus Phoma sp. resulted in the isolation of ergosterol, ergosterol peroxide (EP), and 9,11-dehydroergosterol peroxide (DEP). The bioassay results demonstrated that the three isolates reduced the viability of various cancer cells, with EP being highest in human lung cancer cell line A549 cells. EP induced caspase-dependent apoptosis through mitochondrial damage in A549 cells. Additionally, EP-induced ROS generation and apoptosis were attenuated by ROS-generating enzymes inhibitors and antioxidant N-acetylcysteine, indicated that ROS played an important role in EP-mediated apoptosis in A549 cells. Furthermore, it was observed that EP induced ROS-dependent autophagy, which attenuated apoptosis in A549 cells. On the other hand, EP reduced the LPS/ATP-induced proliferation and migration of A549 cells through attenuated NLRP3 inflammasome activity. Additionally, EP showed synergistic cytotoxic effect with antitumor drug Sorafenib in A549 cell viability inhibition. Furthermore, Micro-Western Array and Western blot analyses demonstrated that the protein levels of EGFR, HSP27, MEK5, AKT1, mTOR, Smad2, Smad3, TAB1, NF-κB, and HIF1-α decreased, while the levels of p-p38α, p-ERK1/2, p-JNK, fibronectin and p27 increased. Collectively, the results of this study demonstrated that EP might be useful to develop a therapeutic candidate for lung cancer complications.

Repositioning of the ß-Blocker Carvedilol as a Novel Autophagy Inducer That Inhibits the NLRP3 Inflammasome.

The NLRP3 inflammasome is a multiprotein complex that plays a key role in the innate immune system, and aberrant activation of this complex is involved in the pathogenesis of inflammatory diseases. Carvedilol (CVL) is an α-, ß-blocker used to treat high blood pressure and congestive heart failure; however, some benefits beyond decreased blood pressure were observed clinically, suggesting the potential anti-inflammatory activity of CVL. In this report, the inhibitory potential of CVL toward the NLRP3 inflammasome and the possible underlying molecular mechanisms were studied. Our results showed that CVL attenuated NLRP3 inflammasome activation and pyroptosis in mouse macrophages, without affecting activation of the AIM2, NLRC4 and non-canonical inflammasomes. Mechanistic analysis revealed that CVL prevented lysosomal and mitochondrial damage and reduced ASC oligomerization. Additionally, CVL caused autophagic induction through a Sirt1-dependent pathway, which inhibited the NLRP3 inflammasome. In the in vivo mouse model of NLRP3-associated peritonitis, oral administration of CVL reduced (1) peritoneal recruitment of neutrophils; (2) the levels of IL-1ß, IL-18, active caspase-1, ASC, IL-6, TNF-α, MCP-1, and CXCL1 in the lavage fluids; and (3) the levels of NLRP3 and HO-1 in the peritoneal cells. Our results indicated that CVL is a novel autophagy inducer that inhibits the NLRP3 inflammasome and can be repositioned for ameliorating NLRP3-associated complications.

In Vitro Production of Echioidinin, 7-O-Methywogonin from Callus Cultures of Andrographis lineata and Their Cytotoxicity on Cancer Cells.

Andrographis lineata is an herbal medicinal plant used in traditional medicine as a substitute for Andrographis paniculata. Here, using mature leaf explants of A. lineata we demonstrate for the first time the callus induction established on MS medium containing 1.0 mg l-1 IAA. Dried callus was subjected to solvent extraction with acetone. Further the acetone residue was separated by silica gel column chromatography, crystallized and characterized on the basis of nuclear magnetic resonance (proton and c13) and liquid chromatographic mass spectroscopy. This analysis revealed the occurrence of two known flavones namely, 7-O-methylwogonin (MW) and Echioidinin (ED). Furthermore, these compounds were tested for their cytotoxicity against leukemic cell line, CEM. We identify that ED and MW induced cytotoxicity in a time- and concentration-dependent manner. Further increase in the LDH release upon treatment with ED and MW further confirmed our cytotoxicity results against leukemic cell line. Strikingly, MW was more potent than ED when compared by trypan blue and MTT assays. Our results recapitulate the utility of callus cultures for the production of plant specific bioactive secondary metabolites instead of using wild plants. Together, our in vitro studies provide new insights of A. lineata callus cultures serving as a source for cancer chemotherapeutic agents.

4-Acetylantroquinonol B inhibits colorectal cancer tumorigenesis and suppresses cancer stem-like phenotype.

4-Acetylantroquinonol B (4-AAQB), closely related to the better known antroquinonol, is a bioactive isolate of the mycelia of Antrodia camphorata, a Taiwanese mushroom with documented anti-inflammatory, hypoglycemic, vasorelaxative, and recently demonstrated, antiproliferative activity. Based on its traditional use, we hypothesized that 4-AAQB may play an active role in the suppression of cellular transformation, tumor aggression and progression, as well as chemoresistance in colorectal carcinoma (CRC). In this study, we investigated the antiproliferative role of 4-AAQB and its underlying molecular mechanism. We also compared its anticancer therapeutic potential with that of antroquinonol and the CRC combination chemotherapy of choice - folinic acid, fluorouracil and oxaliplatin (FOLFOX). Our results showed that 4-AAQB was most effective in inhibiting tumor proliferation, suppressing tumor growth and attenuating stemness-related chemoresistance. 4-AAQB negatively regulates vital oncogenic and stem cell maintenance signal transduction pathways, including the Lgr5/Wnt/ß-catenin, JAK-STAT, and non-transmembrane receptor tyrosine kinase signaling pathways, as well as inducing a dose-dependent downregulation of ALDH and other stemness related factors. These results were validated in vivo, with animal studies showing 4-AAQB possessed comparable tumor-shrinking ability as FOLFOX and potentiates ability of the later to reduce tumor size. Thus, 4-AAQB, a novel small molecule, projects as a potent therapeutic agent for monotherapy or as a component of standard combination chemotherapy.

Purification of kavalactones from Alpinia zerumbet and their protective actions against hydrogen peroxide-induced cytotoxicity in PC12 cells.

This study found that fruit shells of shell ginger (Alpinia zerumbet) are a rich source of the kavalactones dihydro-5,6-dehydrokavain (DDK) and 5,6-dehydrokavain (DK). The fruit shell extraction with hexane resulted in good purity and higher yields of DDK and DK than did chloroform, ethanol, 10% ethanol, methanol or water. Additionally, this study examined the neuroprotective effects of DDK and DK against H2O2-induced cytotoxicity in PC12 cells and the possible molecular mechanisms involved. 16 h after stimulation with 400 µM H2O2, the viability (MTT reduction) of PC12 cells decreased while membrane damage (LDH release) was noticeably increased. However, pretreatment for 6 h with DDK and DK (1 µM, 5 µM, 10 µM and 50 µM) rescued PC12 cells from H2O2-induced cytotoxicity, as evidenced by decreased LDH release and increased cell viability. DDK and DK inhibit the MAPK family member p38, activate AKT, and reduce caspase-3 activity. DDK also reduced the oxidative status in H2O2-treated PC12 cells. Together, our data indicate that the A. zerumbet constituents, DDK and DK, exert a protective effect against oxidative stress-induced PC12 cell death and that the regulation of p-Akt and the p38 MAPK, and of oxidative states may be involved.

3,3',4', 5'-Tetramethoxychalcone inhibits human oral cancer cell proliferation and migration via p53-mediated mitochondrial-dependent apoptosis.

BACKGROUND/AIM: The current study aimed to identify an attractive target against human oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: The effect of 3,3',4',5'-tetramethoxychalcone (TMC) on OSCC cell proliferation, cell-cycle phase distribution, expression of markers of cell apoptosis, and cell migration were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, western blot, and transwell migration assay, respectively. RESULTS: Experimental results revealed that TMC inhibited the OSCC cell proliferation (fifty percent inhibitory concentrations range=1.0-4.5 µM) by inducing G2/M phase arrest of the cell cycle. TMC caused DNA double-strand breaks, and enhanced expression of caspase-3 and -9, poly (ADP-ribose) polymerase, cytochrome c, calpain-1 and -2, phosphorylation of histone H2AX, phosphorylation of checkpoint kinases 2, p53, BCL2-antagonist/killer and BCL2-associated × protein, while reducing the mitochondrial membrane potential, and expression of B-cell lymphoma-2. In addition, TMC reduced the migration potential of OSCC cells by attenuating the C-C chemokine ligand 5/C-C chemokine receptor type 5 axis. CONCLUSION: These data indicate that TMC may be considered an interesting target for further development of chemotherapeutic agents against oral cancer.

Destruxin B inhibits hepatocellular carcinoma cell growth through modulation of the Wnt/ß-catenin signaling pathway and epithelial-mesenchymal transition.

The aberrant activation of Wnt/ß-catenin signaling plays an important role in the carcinogenesis and progression of hepatocellular carcinoma (HCC). Therefore, the Wnt/ß-catenin signaling molecules are attractive candidates for the development of targeted therapies for this disease. The present study showed that destruxin B (DB) inhibits the proliferation and induces the apoptosis of HCC cells by decreasing the protein expression of anti-apoptotic Bcl-2 and Bcl-xL and increasing the expression of the proapoptotic protein Bax. More importantly, DB also attenuates Wnt-signaling in HCC cells by downregulating ß-catenin, Tcf4, and ß-catenin/Tcf4 transcriptional activity, which results in the decreased expression of ß-catenin target genes, such as cyclin D1, c-myc, and survivin. Furthermore, DB affects the migratory and invasive abilities of Sk-Hep1 cells through the suppression of markers of the epithelial-mesenchymal transition (EMT). A synergistic anti-proliferative and migratory effect was achieved using the combination of DB and sorafenib in Sk-Hep1 cells. In conclusion, DB acts as a novel Wnt/ß-catenin inhibitor and reduces the aggressiveness and invasive potential of HCC by altering the cells' EMT status and mobility. DB in combination with sorafenib may be considered for future clinical use for the management of metastatic HCC.

Ovatodiolide inhibits the maturation of allergen-induced bone marrow-derived dendritic cells and induction of Th2 cell differentiation.

Ovatodiolide was a unique macrocyclic diterpenoid isolated from the traditional Chinese medicinal herb Anisomeles indica. The present study attempted to examine the ovatodiolide effects on dendritic cell (DC) maturation and immuno-stimulatory activities. The effects of ovatodiolide on DC surface molecule expression, cytokine production, and capacity to induce T-cell differentiation were examined in ovalbumin (OVA)/thymic stromal lymphopoietin (TSLP)-stimulated DCs. Ovatodiolide attenuated the expression of DC surface molecules CD80, CD86, histocompatibility complex (MHC) class II, and Th2 subset of CD4(+) T cells co-stimulatory molecule-OX40 ligand production. Additionally, ovatodiolide suppressed the CD4(+) T cells proliferation, and production of inflammatory cytokines interleukin (IL)-4, IL-5, and tumor necrosis factor (TNF)-α. This study may be useful to develop ovatodiolide as a therapeutic adjuvant.

A sesquiterpene lactone antrocin from Antrodia camphorata negatively modulates JAK2/STAT3 signaling via microRNA let-7c and induces apoptosis in lung cancer cells.

Lung cancer is the leading cause of cancer deaths worldwide and current therapies fail to treat this disease in majority of cases. Antrodia camphorata is a medicinal mushroom being widely used as food dietary supplement for cancer prevention. The sesquiterpene lactone antrocin is the most potent among >100 secondary metabolites isolated from A. camphorata. However, the molecular mechanisms of antrocin-mediated anticancer effects remain unclear. In this study, we found that antrocin inhibited cell proliferation in two non-small-cell lung cancer cells, namely H441 (wild-type epidermal growth factor receptor, IC50 = 0.75 µM) and H1975 (gefitnib-resistant mutant T790M, IC50 = 0.83 µM). Antrocin dose dependently suppressed colony formation and induced apoptosis as evidenced by activated caspase-3 and increased Bax/Bcl2 ratio. Gene profiling studies indicated that antrocin downregulated Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway. We further demonstrated that antrocin suppressed both constitutively activated and interleukin 6-induced STAT3 phosphorylation and its subsequent nuclear translocation. Such inhibition is found to be achieved through the suppression of JAK2 and interaction between STAT3 and extracellular signal-regulated kinase. Additionally, antrocin increased microRNA let-7c expression and suppressed STAT signaling. The combination of antrocin and JAK2/STAT3 gene silencing significantly increased apoptosis in H441 cells. Such dual interruption of JAK2 and STAT3 pathways also induced downregulation of antiapoptotic protein mcl-1 and increased caspase-3 expression. In vivo intraperitoneal administration of antrocin significantly suppressed the growth of lung cancer tumor xenografts. Our results indicate that antrocin may be a potential therapeutic agent for human lung cancer cells through constitutive inhibition of JAK2/STAT3 pathway.

Inhibition of Helicobacter pylori CagA-Induced Pathogenesis by Methylantcinate B from Antrodia camphorata.

The bacterial pathogen Helicobacter pylori (Hp) is the leading risk factor for the development of gastric cancer. Hp virulence factor, cytotoxin-associated gene A (CagA) interacted with cholesterol-enriched microdomains and leads to induction of inflammation in gastric epithelial cells (AGS). In this study, we identified a triterpenoid methylantcinate B (MAB) from the medicinal mushroom Antrodia camphorata which inhibited the translocation and phosphorylation of CagA and caused a reduction in hummingbird phenotype in HP-infected AGS cells. Additionally, MAB suppressed the Hp-induced inflammatory response by attenuation of NF-κB activation, translocation of p65 NF-κB, and phosphorylation of IκB-α, indicating that MAB modulates CagA-mediated signaling pathway. Additionally, MAB also suppressed the IL-8 luciferase activity and its secretion in HP-infected AGS cells. On the other hand, molecular structure simulations revealed that MAB interacts with CagA similarly to that of cholesterol. Moreover, binding of cholesterol to the immobilized CagA was inhibited by increased levels of MAB. Our results demonstrate that MAB is the first natural triterpenoid which competes with cholesterol bound to CagA leading to attenuation of Hp-induced pathogenesis of epithelial cells. Thus, this study indicates that MAB may have a scope to develop as a therapeutic candidate against Hp CagA-induced inflammation.

Anticancer effects of eleven triterpenoids derived from Antrodia camphorata.

Eleven derivatives from Antrodia camphorata were isolated in order to evaluate their selective cytotoxicity toward 14 types of human cancer cell and two non-transformed cell types. Among these triterpenoids, methyl antcinate A (MAA) exhibited the most potent spectrum of anticancer effects in KB cells, four different oral cancer cell lines (TSCCa, GNM, OC-2, and OEC-M1), Panc-1, BT474, PC-3, OVCAR-3, HeLa, and U2OS cells with high selectivity indices (CC(50)/IC(50)). The expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and poly(ADP-ribose) polymerase (PARP) of PC-3 cells tested by western blotting suggested that MAA exerts cell death through the caspase-dependent cascade and the Bax-mediated mitochondrial apoptotic pathway, not only on liver and oral cancer cells but on other types as well, including prostate cancer, in a dose-dependent manner. In addition to MAA, methyl antcinate B, dehydroeburicoic acid, and 15α-acetyl-dehydrosulfurenic acid also exhibited significant selective cytotoxic effects to respective cancer cells. Modifications of these triterpenoids may lead to the development of more potent anticancer drugs.

Aqueous extract of Anisomeles indica and its purified compound exerts anti-metastatic activity through inhibition of NF-κB/AP-1-dependent MMP-9 activation in human breast cancer MCF-7 cells.

Anisomeles indica popularly known in Taiwan as 'yu-chen-tsao' has been traditionally used as an anticancer and anti-inflammatory agent; however, little is known about its anti-metastatic potential. Therefore, we attempted in this study to examine the anti-metastatic potential of A. indica aqueous extract (AI), its isolated compounds apigenin, ovatodiolide, ß-sitosterol and acteoside in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced human breast adenocarcinoma MCF-7 cells. Among the test agents, crude extract AI and pure compound apigenin potently suppressed the TPA-induced MCF-7 cells migration and invasion. In addition, AI and apigenin time- and dose-dependently down regulated the matrix metalloproteinase (MMP)-9 enzymatic activities and its mRNA expression. Furthermore, AI and apigenin also down regulated the nuclear factor (NF)-κB subunit p65, and activator protein (AP)-1 subunit c-Fos proteins expression in nucleus and, transcriptional activity of NF-κB and AP-1. This is the first report on the anti-metastatic potential of A. indica that suppressed the cancer cell invasion through the inhibition of MMP-9 enzyme via NF-κB/AP-1 signaling. Taken together, our data indicate that A. indica can be considered as a source of new anti-metastatic agent for food and pharmaceutical industries.

Preclinical evaluation of destruxin B as a novel Wnt signaling target suppressing proliferation and metastasis of colorectal cancer using non-invasive bioluminescence imaging.

In continuation to our studies toward the identification of direct anti-cancer targets, here we showed that destruxin B (DB) from Metarhizium anisopliae suppressed the proliferation and induced cell cycle arrest in human colorectal cancer (CRC) HT29, SW480 and HCT116 cells. Additionally, DB induced apoptosis in HT29 cells by decreased expression level of anti-apoptotic proteins Bcl-2 and Bcl-xL while increased pro-apoptotic Bax. On the other hand, DB attenuated Wnt-signaling by downregulation of ß-catenin, Tcf4 and ß-catenin/Tcf4 transcriptional activity, concomitantly with decreased expression of ß-catenin target genes cyclin D1, c-myc and survivin. Furthermore, DB affected the migratory and invasive ability of HT29 cells through suppressed MMPs-2 and -9 enzymatic activities. We also found that DB targeted the MAPK and/or PI3K/Akt pathway by reduced expression of Akt, IKK-α, JNK, NF-κB, c-Jun and c-Fos while increased that of IκBα. Finally, we demonstrated that DB inhibited tumorigenesis in HT29 xenograft mice using non-invasive bioluminescence technique. Consistently, tumor samples from DB-treated mice demonstrated suppressed expression of ß-catenin, cyclin D1, survivin, and endothelial marker CD31 while increased caspase-3 expression. Collectively, our data supports DB as an inhibitor of Wnt/ß-catenin/Tcf signaling pathway that may be beneficial in the CRC management.

Effects of andrographolide and 14-deoxy-11,12-didehydroandrographolide on cultured primary astrocytes and PC12 cells.

AIMS: To test the effects of andrographolide (AP1) and 14-deoxy-11,12-didehydroandrographolide (AP2) on pheochromocytoma cell line 12 (PC12) cells in an astrocyte-rich environment. MAIN METHODS: The abilities of AP1 and AP2 to reduce the secretion of pro-inflammatory cytokines Interleukin (IL)-1, IL-6, and Tumor necrosis factor (TNF)-α from stimulated astrocytes were tested. In addition, the abilities of AP1 and AP2 to reduce oxidative stress in astrocytes were tested using an oxidative-sensitive fluorescent dye. The reduction of chondroitin sulfate proteoglycan (CSPG) in stimulated astrocytes was tested using the dot blot method. Reduction of H(2)O(2)-induced death was tested in PC12 cells. Astrocyte-conditioned medium (ACM) and TNF-α-stimulated astrocyte-conditioned medium (SACM) were used to assess the effects of AP2 on PC12 cells treated with H(2)O(2). KEY FINDINGS: AP1 and AP2 reduced pro-inflammatory cytokines, reactive oxygen species (ROS), and CSPG in TNF-α stimulated astrocytes. AP1 protected H(2)O(2)-treated PC12 cells cultured in ACM. Co-incubation of PC12 cells in H(2)O(2), and ACM collected from AP1 treated astrocytes did not prevent cell death. SIGNIFICANCE: AP1 and AP2 effectively ameliorated astrocytic pro-inflammatory reactions and prevented PC12 cell death with different efficacies. These compounds may be candidates for treatment of spinal-cord injury and neurodegeneration.

Antcin B and its ester derivative from Antrodia camphorata induce apoptosis in hepatocellular carcinoma cells involves enhancing oxidative stress coincident with activation of intrinsic and extrinsic apoptotic pathway.

The triterpenoids methylantcinate B (MAB) and antcin B (AB), isolated from the medicinal mushroom Antrodia camphorata , have been identified as strong cytotoxic agents against various type of cancer cells; however, the mechanisms of MAB- and AB-induced cytotoxicity have not been adequately explored. This study investigated the roles of caspase cascades, reactive oxygen species (ROS), DNA damage, mitochondrial disruption, and Bax and Bcl-2 proteins in MAB- and AB-induced apoptosis of hepatocellular carcinoma (HCC) HepG2 cells. Here, we showed that MAB and AB induced apoptosis in HepG2 cells, as characterized by increased DNA fragmentation, cleavage of PARP, sub-G1 population, chromatin condensation, loss of mitochondrial membrane potential, and release of cytochrome c. Increasing the levels of caspase-2, -3, -8, and -9 activities was involved in MAB- and AB-induced apoptosis, and they could be attenuated by inhibitors of specific caspases, indicating that MAB and AB triggered the caspase-dependent apoptotic pathway. Additionally, the enhanced apoptotic effect correlates with high expression of Fas, Fas ligand, as well as Bax and decreased protein levels of Bcl-(XL) and Bcl-2, suggesting that both the extrinsic and intrinsic apoptosis pathways were involved in the apoptotic processes. Incubation of HepG2 cells with antioxidant enzymes superoxide dismutase and catalase and antioxidants N-acetylcysteine and ascorbic acid attenuated the ROS generation and apoptosis induced by MAB and AB, which indicate that ROS plays a pivotal role in cell death. NADPH oxidase activation was observed in MAB- and AB-stimulated HepG2 cells; however, inhibition of such activation by diphenylamine significantly blocked MAB- and AB-induced ROS production and increased cell viability. Taken together, our results provide the first evidence that triterpenoids MAB and AB induced a NADPH oxidase-provoked oxidative stress and extrinsic and intrinsic apoptosis as a critical mechanism of cause cell death in HCC cells.

Insulin-Mimetic Action of Rhoifolin and Cosmosiin Isolated from Citrus grandis (L.) Osbeck Leaves: Enhanced Adiponectin Secretion and Insulin Receptor Phosphorylation in 3T3-L1 Cells.

Citrus grandis (L.) Osbeck (red wendun) leaves have been used in traditional Chinese medicine to treat several illnesses including diabetes. However, there is no scientific evidence supporting these actions and its active compounds. Two flavone glycosides, rhoifolin and cosmosiin were isolated for the first time from red wendun leaves and, identified these leaves are rich source for rhoifolin (1.1%, w/w). In differentiated 3T3-L1 adipocytes, rhoifolin and cosmosiin showed dose-dependent response in concentration range of o.oo1-5 µM and 1-20 µM, respectively, in biological studies beneficial to diabetes. Particularly, rhoifolin and cosmosiin at 0.5 and 20 µM, respectively showed nearly similar response to that 10 nM of insulin, on adiponectin secretion level. Furthermore, 5 µM of rhoifolin and 20 µM of cosmosiin showed equal potential with 10 nM of insulin to increase the phosphorylation of insulin receptor-ß, in addition to their positive effect on GLUT4 translocation. These findings indicate that rhoifolin and cosmosiin from red wendun leaves may be beneficial for diabetic complications through their enhanced adiponectin secretion, tyrosine phosphorylation of insulin receptor-ß and GLUT4 translocation.