Crude extract of Euphorbia formosana induces apoptosis of DU145 human prostate cancer cells acts through the caspase-dependent and independent signaling pathway.

Prostate cancer is the most frequently diagnosed malignancy in men and the second highest contributor of male cancer mortality. The crude extract of Euphorbia formosana (CEEF) has been used for treatment of different diseases but the cytotoxic effects of CEEF on human cancer cells have not been reported. The purpose of the present experiments was to determine effects of CEEF on cell cycle distribution and induction of apoptosis in DU145 human prostate cancer cells in vitro. Contrast-phase microscope was used for examining cell morphological changes. Flow cytometric assays were used for cell viability, cell cycle, apoptosis, reactive oxygen species, and Ca2+ production and mitochondria membrane potential (ΔΨm ). Western blotting was used for examining protein expression of cell cycle and apoptosis associated proteins. Real-time PCR was used for examining mRNA levels of caspase-3, -8, and -9, AIF, and Endo G. Confocal laser microscope was used to examine the translocation of AIF, Endo G, and cytochrome in DU145 cells after CEEF exposure. CEEF-induced cell morphological changes, decreased the percentage of viable cells, and induced S phase arrest and apoptosis in DU145 cells. Furthermore, CEEF promoted RAS and Ca2+ production and reduced ΔΨm levels. Real-time QPCR confirmed that CEEF promoted the mRNA expression of caspase-3 and -9, AIF and Endo G and we found that AIF and Endo G and cytochrome c were released from mitochondria. Taken together, CEEF-induced cytotoxic effects via ROS production, induced S phase arrest and induction of apoptosis through caspase-dependent and independent and mitochondria-dependent pathways in DU245 cancer cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1600-1611, 2016.

Retinoic acid receptor agonist activity of naturally occurring diterpenes.

Recent accumulating evidence indicates that all-trans retinoic acid (ATRA) may be useful for preventing or treating inflammation, allergy, and autoimmune diseases, despite its severe side effects. In this study, screening of 99 crude drugs for retinoic acid receptor (RAR) ligands by luciferase reporter assay demonstrated that the methanol extract of Aralia cordata Rhizoma most effectively activates the transcriptional activity of RARα. Pimaradienoic acid (ent-pimara-8(14),15-dien-19-oic acid) was subsequently isolated as the constituent capable of activating RAR. Pimaric acid and abietic acid, which have similar structures to pimaradienoic acid, were also found to be novel RAR agonists, although abietic acid only slightly activated peroxisome proliferator-activated receptor gamma. These three natural RAR agonists with diterpene structures, while structurally different from ATRA, were able to increase the mRNA levels of the constitutive androstane receptor in HepG2 cells, induce F9 cell differentiation followed by Cyp26a1 mRNA expression, and differentiate HL-60 cells via RAR activation in a different manner from ATRA. These results demonstrate that some diterpenes exist as naturally occurring RAR agonists and that the differences in chemical structure between ATRA and these diterpenes may induce distinct gene activation and a specific cellular response.

A naturally occurring rexinoid, honokiol, can serve as a regulator of various retinoid x receptor heterodimers.

We investigated the properties of honokiol, a natural rexinoid, as a regulator of retinoid X receptor (RXR) heterodimers with various partner nuclear receptors (NRs), in comparison with those of the synthetic rexinoid bexarotene. Honokiol alone was hardly capable of activating peroxisome proliferator-activated receptor (PPAR) γ/RXR, RXR/liver X receptor (LXR), and RXR/vitamin D receptor (VDR) heterodimers, whereas it effectively potentiated their activation by agonists for the partner NRs of the RXR heterodimers. These findings were further supported by increased mRNA and protein levels for the respective NR target genes. Bexarotene alone activated PPARγ/RXR and RXR/LXR heterodimers, but not RXR/VDR heterodimers, and facilitated the activation of all three RXR heterodimers by the respective PPARγ, LXR, and VDR agonists. When the potencies of honokiol and bexarotene were compared, honokiol was able to serve as a subsidiary agonist in the activation of RXR heterodimers in a similar manner to bexarotene. However, it seemed to potentiate the activation of PPARγ/RXR heterodimers by the PPARγ agonist rosiglitazone more efficiently than bexarotene, and was a less potent RXR agonist than bexarotene. In conclusion, we have demonstrated that honokiol is a rexinoid that possesses distinct properties from bexarotene, and mainly has subsidiary roles in the activation of RXR heterodimers by potentiating the activation of RXR heterodimers by agonists for the partner NRs.

Anti-inflammatory activities of tormentic acid from suspension cells of Eriobotrya Japonicaex vivo and in vivo.

Anti-inflammatory effects of tormentic acid (TA) were investigated ex vivo and in vivo. TA decreased the paw edema at the 4th and 5thhour after λ-carrageenin (Carr) administration, and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the liver tissue. TA also significantly attenuated the thiobarbituric acid reactive substances (TBARS) level in the edematous paw at the 5thhour after Carr injection. TA decreased the nitric oxide (NO) levels on the serum level and diminished the serum tumour necrosis factor (TNF-α) at the 5thhour after Carr injection. Western blotting revealed that the TA decreased Carr-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions. As per results, the anti-inflammatory mechanisms of TA might be correlated to the decrease in the level of TBARS, iNOS, and COX-2 in the edema paw via increasing the activities of CAT, SOD, and GPx in the liver.

Separation and isolation methods for analysis of the active principles of Sho-saiko-to (SST) oriental medicine.

Sho-saiko-to (SST) was introduced into Japan as an oriental classical medicine from China approximately 1500 years ago, and it is currently the most representative Kampo medicine (traditional Japanese medicine). SST is manufactured in Japan as an ethical drug on a modern industrial scale in which the quality of ingredients is standardized with Good Manufacturing Practices (GMP) regulation. SST is widely used for the treatment of chronic hepatitis. Experimental and clinical studies including multi-center, placebo-controlled, double-blind studies have demonstrated the various pharmacological effects of SST. SST is prepared from the hot water extraction of seven raw materials, therefore many kinds of constituents are included. Three-dimensional (3D) HPLC analysis is useful for obtaining many kinds of constituents, especially low molecular ultraviolet (UV) quenching compounds, contained in SST as well as its fractions. Fingerprint pattern provided by 3D HPLC analysis makes possible to identify the overall-viewing of SST. Databases of UV spectra of the components of medicinal herbs obtained by reversed-phase (RP) HPLC using a photodiode array (PDA) and fingerprint patterns of crude drugs made by 3D HPLC analysis facilitate the identification, analysis and quality of herbal drugs. Studies using both PDA HPLC and an amino acid analysis with a fluorometric detector have found that SST contains fifteen major low molecular compounds (i.e. baicalin, wogonin-7-O-glucuronide, liquiritin, their three aglycons, liquiritin apioside, glycyrrhizin, saikosaponin b1, saikosaponin b2, ginsenoside Rg1, ginsenoside Rb1, (6)-gingerol, (6)-shogaol and arginine). These compounds have various pharmacological actions, and are assumed to be responsible, at least partly, for the pharmacological effects of SST. Although there have only been a few investigations on high molecular compounds with pharmacological actions contained in SST, several kinds of polysaccharides have been isolated from constituent herbs of SST. This review paper summarizes analytical methods of separation, isolation and identification of compounds with biological activities from SST, which is a mixture drug of medicinal herbs. Accordingly, this paper would not focus on methods of separation, isolation and analysis of particular compounds from each constituent herb of SST.

Phenethyl isothiocyanate suppresses EGF-stimulated SAS human oral squamous carcinoma cell invasion by targeting EGF receptor signaling.

Phenethyl isothiocyanate (PEITC) is a natural compound that is involved in chemoprevention as well as inhibition of cell growth and induction of apoptosis in several types of cancer cells. Previous studies have revealed that PEITC suppresses the invasion of AGS gastric and HT-29 colorectal cancer cells. However, the effects of PEITC on the metastasis of SAS oral cancer cells remain to be determined. Our results showed that PEITC treatment inhibited the invasion of EGF-stimulated SAS cells in a concentration-dependent manner, but appeared not to affect the cell viability. The expression and enzymatic activities of matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9) were suppressed by PEITC. Concomitantly, we observed an increase in the protein expression of both tissue inhibitor of metalloproteinase-1 (TIMP-1) and -2 (TIMP-2) in treated cells. Furthermore, PEITC treatments decreased the protein phosphorylation of epidermal growth factor receptor (EGFR) and downstream signaling proteins including PDK1, PI3K (p85), AKT, phosphorylated IKK and IκB to inactivate NF-κB for the suppression of MMP-2 and MMP-9 expression. In addition, PEITC can trigger the MAPK signaling pathway through the increase in phosphorylated p38, JNK and ERK in treated cells. Our data indicate that PEITC is able to inhibit the invasion of EGF-stimulated SAS oral cancer cells by targeting EGFR and its downstream signaling molecules and finally lead to the reduced expression and enzymatic activities of both MMP-2 and MMP-9. These results suggest that PEITC is promising for the therapy of oral cancer metastasis.

Crude extract of Euphorbia formosana inhibits the migration and invasion of DU145 human prostate cancer cells: The role of matrix metalloproteinase-2/9 inhibition via the MAPK signaling pathway.

Prostate cancer is a common worldwide health problem in males with a poor prognosis due in part to tumor invasion and migration. The crude extract of Euphorbia formosana (CEEF) has been used for the treatment of numerous diseases, however, its effects on the migration and invasion of prostate cancer cells have yet to be examined. In the present study, we investigated the effects of CEEF on the migration and invasion of DU145 human prostate cancer cells in vitro. The wound healing assay and the Matrigel-uncoated migration assay were used to examine the migration of cancer cells. Western blotting was used to examine the levels of proteins associated with migration and invasion, and gelatin zymography was used to examine the secretion levels of matrix metalloproteinases-2 and -9 (MMP­2/9) from DU145 cells following exposure to CEEF. The results indicated that CEEF suppressed the migration and invasion of DU145 prostate cancer cells and that these effects are exerted in a concentration- and time-dependent manner. CEEF inhibited the ERK1/2, p38, JNK, SOS1, PKC, PI3K and MMP-2/9 protein expression in DU145 cells. The results demonstrated that CEEF suppressed the migration and invasion of DU145 cells through inhibition of the mitogen-activated protein kinase (MAPK) signaling pathway resulting in the inhibition of MMP-2/9 in DU145 human prostate cancer cells.

Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells.

Kaempferol is a natural flavonoid that possesses anti-proliferative and apoptosis-inducing activities in several cancer cell lines. In the present study, we investigated the anti-metastatic activity of kaempferol and its molecular mechanism(s) of action in human osteosarcoma cells. Kaempferol displayed inhibitory effects on the invasion and adhesion of U-2 osteosarcoma (OS) cells in a concentration-dependent manner by Matrigel Transwell assay and cell adhesion assay. Kaempferol also inhibited the migration of U-2 OS cells in a concentration-dependent manner at different treatment time points by wound-healing assay. Additional experiments showed that kaempferol treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator (uPA) by gelatin and casein-plasminogen zymography assays and western blot analyses. Kaempferol also downregulated the mRNA levels of MMP-2 and MMP-9 by quantitative PCR analyses. Furthermore, kaempferol was able to reduce the protein phosphorylation of ERK, p38 and JNK by western blotting. By electrophoretic mobility-shift assay (EMSA), we demonstrated that kaempferol decreased the DNA binding activity of AP-1, an action likely to result in the reduced expression of MMP-2, MMP-9 and uPA. Collectively, our data showed that kaempferol attenuated the MAPK signaling pathways including ERK, JNK and p38 and resulted in the decreased DNA binding ability of AP-1, and hence, the downregulation in the expression and enzymatic activities of MMP-2, MMP-9 and uPA, contributing to the inhibition of metastasis of U-2 OS cells. Our results suggest a potential role of kaempferol in the therapy of tumor metastasis of OS.

AKT serine/threonine protein kinase modulates baicalin-triggered autophagy in human bladder cancer T24 cells.

Baicalin is one of the major compounds in the traditional Chinese medicinal herb from Scutellaria baicalensis Georgi. We investigated the molecular mechanisms of cell autophagy induced by baicalin in human bladder cancer T24 cells. Baicalin inhibited cell survival as shown by MTT assay and increased cell death by trypan blue exclusion assay in a concentration-dependent manner. Baicalin did not induce apoptotic cell death in T24 cells by TUNEL and caspase-3 activity assay. Baicalin induced the acidic vesicular organelle cell autophagy marker, manifested by acridine orange (AO) and monodansylcadaverine (MDC) staining and cleavage of microtubule-associated protein 1 light chain 3 (LC3). The protein expression levels of the Atg 5, Atg 7, Atg 12, Beclin-1 and LC3-II were upregulated in T24 cells after baicalin treatment. Inhibition of autophagy by 3-methyl-adenine (an inhibitor of class III phosphatidylinositol-3 kinase; 3-MA) reduced the cleavage of LC3 in T24 cells after baicalin treatment. Furthermore, protein expression levels of phospho-AKT (Ser473) and enzyme activity of AKT were downregulated in T24 cells after baicalin treatment. In conclusion, baicalin triggered cell autophagy through the AKT signaling pathway in T24 cells.

Astaxanthin functions differently as a selective peroxisome proliferator-activated receptor γ modulator in adipocytes and macrophages.

Astaxanthin (ASX), an oxygenated carotenoid (xanthophyll), has previously been shown to exert ameliorative effects on obesity and insulin resistance, but the underlying mechanisms were not clearly elucidated. In the present study, we investigated whether ASX serves as a novel selective peroxisome proliferator-activated receptor (PPAR) γ modulator. Analyses of PPARγ binding by CoA-BAP assays revealed that ASX bound to PPARγ in a dose-dependent manner. However, ASX was unable to activate transcription in PPARγ reporter assays, although it antagonized transcriptional activation by the PPARγ agonist rosiglitazone (RGZ). When the molecular interactions between PPARγ and three coactivators were examined, ASX increased the interactions of PPARγ with transcriptional intermediary factor 2 (TIF2) and steroid receptor coactivator-1 (SRC-1), but not cAMP responsive element-binding protein (CREB)-binding protein (CBP). In addition, ASX effectively blocked the increase in CBP recruitment to PPARγ mediated by RGZ. ASX alone did not stimulate 3T3-L1 cell differentiation, although it antagonized 3T3-L1 cell differentiation and lipid accumulation induced by RGZ, similar to the PPARγ antagonist GW9662. When the effects of cotreatment of 3T3-L1 cells with ASX and RGZ were determined based on the mRNA levels of PPARγ target genes, ASX effectively reduced the mRNA levels of aP2 and lipoprotein lipase, but not CD36. Intriguingly, ASX was capable of inducing PPARγ target genes such as liver X receptor, CD36 and ABCA1 in thioglycollate-elicited peritoneal macrophages. Collectively, the present findings indicate that ASX is a novel selective PPARγ modulator that acts as an antagonist or agonist depending on the cell context.

Puerariae flos alleviates metabolic diseases in Western diet-loaded, spontaneously obese type 2 diabetic model mice.

Puerariae flos extract (PFE) has been reported to have many effects, including preventing the development of hangovers, liver protective effects, and an estrogenic effect. In addition, some papers reported that PFE is effective against metabolic diseases, with hypolipidemic and hypoglycemic effects. However, the mechanism underlying such effects remains unclear. For the purpose of clarifying the effect of PFE on metabolic diseases related to the accumulation of visceral fat and to determine the mechanism of such action, TSOD mice, a multifactorial genetic disease animal model that spontaneously develops various metabolic diseases such as obesity and type 2 diabetes, were given a Western diet (WTD) as an environmental factor to prepare a disease model (TSOD-WTD). When TSOD mice were loaded with WTD, it was confirmed that metabolic diseases such as obesity and abnormal glucose/lipid metabolism are aggravated. In contrast, PFE treatment to TSOD-WTD mice was shown to suppress body weight gain and visceral fat accumulation, alleviated the abnormal glucose tolerance and hyperinsulinemia, as well as causing an increase in blood adiponectin. Furthermore, the suppression of liver enlargement was observed in PFE-treated mice, with suppression of fatty degeneration and anti-inflammatory effect. In addition, to clarify the mechanism of the hyperlipidemia-alleviating effects in the liver, we investigated the effect of PFE on the expression of genes involved in cholesterol homeostasis. PFE was associated with a significant increase in gene expression for cholesterol synthesis rate-limiting enzyme HMG-CoA reductase, cholesterol catabolization enzyme Cyp7A1, bile salt export pump adenosine triphosphate-binding cassette transporter B11, and low-density lipoprotein receptor involved in cholesterol uptake. The above results suggest that PFE acts to alleviate the effects of various metabolic diseases based on the accumulation of visceral adipose tissue, including obesity, diabetes, and hyperlipidemia, with the promotion of catabolization/excretion of cholesterol in the liver being a key mechanism of action.

Hepatoprotective effect of the ethanol extract of Vitis thunbergii on carbon tetrachloride-induced acute hepatotoxicity in rats through anti-oxidative activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Vitis thunbergii var. taiwaniana are traditionally used for the treatment of diarrhea, fracture and injury, jaundice, and hepatitis in Taiwan. AIM OF THE STUDY: The hepatoprotective activity of its plant extracts seems to be been associated with its antioxidant activity. This paper aims to investigate the in vitro and in vivo antioxidant effects of the ethanol extract of Vitis thunbergii (EVT). MATERIALS AND METHODS: In HPLC analysis, the fingerprint chromatogram of EVT was established. Antioxidant ability of EVT was investigated by employing several established in vitro methods. In vivo antioxidant activity was tested against CCl(4)-induced toxicity in mice. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected in the blood to indicate hepatic injury. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed for the degree of hepatic injury. RESULTS: EVT exhibited strong antioxidant ability in vitro. After oral administration of EVT significantly decreased ALT and AST, and ameliorated the oxidative stress in hepatic tissue and increased the activity of CAT, SOD, GPx, and GSH. Serum tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), and nitric oxide (NO) were decreased in the group treated with CCl(4) plus EVT. Western blotting revealed that EVT blocked protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in CCl(4)-treated rats, significantly. Histopathological examination of livers showed that EVT reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl(4)-treated rats. CONCLUSION: This study suggests that EVT possesses antioxidant effects in vitro and hepatoprotective effect on acute liver injuries induced by CCl(4)in vivo, and the results suggested that the effect of EVT against CCl(4)-induced liver damage is related to its antioxidant properties.

Epigallocatechin gallate sensitizes CAL-27 human oral squamous cell carcinoma cells to the anti-metastatic effects of gefitinib (Iressa) via synergistic suppression of epidermal growth factor receptor and matrix metalloproteinase-2.

Human head and neck squamous cell carcinoma (HNSCC) is a major cause of cancer-related death during the last decade due to its related metastasis and poor treatment outcomes. Gefitinib (Iressa), a tyrosine kinase inhibitor has been reported to reduce the metastatic abilities of oral cancer. Previous studies have shown that epigallocatechin gallate (EGCG), a green tea polyphenol, possesses cancer chemopreventive and anticancer activity. However, the mechanisms involved in the suppression of invasion and metastasis of human oral cancer cells following co-incubation with gefitinib and EGCG remain poorly understood. In the present study, we attempted to investigate the synergistic effects of a combined treatment of gefitinib and EGCG in CAL-27 cells in vitro and to elucidate the underlying molecular mechanisms associated with the supression of cell migration and invasion. In the present study, we found that the individual treatments or the combined treatment of gefitinib and EGCG synergistically inhibited the invasion and migration of CAL-27 cells using Transwell invasion and wound-healing scratch assays, respectively. Similarly, gefitinib in combination with EGCG synergistically attenuated enzymatic activity and the protein expression of MMP-2 in CAL-27 cells. Furthermore, individual or combined treatment with EGCG and gefitinib suppressed the protein expression of p-EGFR and the phosphorylated protein levels of ERK, JNK, p38 and AKT and displayed inhibitory effects on metastatic ability of CAL-27 cells. Combined effects of EGCG and gefitinib-altered anti-metastatic actions for related gene expression were observed using DNA microarray analysis. Importantly, EGCG sensitizes CAL-27 cells to gefitinib-suppressed phosphorylation of epidermal growth factor receptor (EGFR in vitro. Taken together, our results suggest that the synergistic suppression of the metastatic ability of CAL-27 cells after EGCG and gefitinib individual or combined treatment are mediated through mitogen-activated protein kinase (MAPK) signaling. Our novel findings provide potential insights into the mechanism involved with synergistic responses of gefitinib and EGCG against the progression of oral cancer.

Lanostane triterpenoids and sterols from Antrodia camphorata.

Four lanostane triterpenes, 3,7,11-trioxo-5α-lanosta-8,24(E)-dien-26-oic acid, methyl 11α-3,7-dioxo-5α-lanosta-8,24(E)-dien-26-oate, methyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, and ethyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, two sterols, (14α,22E)-14-hydroxyergosta-7,22-diene-3,6-dione and a steroid named as camphosterol A were isolated from a mixture of fruiting bodies and mycelia of solid cultures of Antrodia camphorata. The ¹H and ¹³C NMR spectra of all compounds were fully assigned using a combination of 2D NMR experiments, including COSY, HMQC, HMBC and NOESY sequences. Six compounds were evaluated for cytotoxicity against several human tumor cell lines, all of which has moderate activity.

Inhibition of invasion and migration by newly synthesized quinazolinone MJ-29 in human oral cancer CAL 27 cells through suppression of MMP-2/9 expression and combined down-regulation of MAPK and AKT signaling.

Anti-metastasis by reducing cellular migration and invasion and by deregulating the expression of matrix metalloproteinases (MMPs) is a therapeutic approach for cancer treatment. The objective of this study focused on the effects of the novel compound 6-pyrrolidinyl-2-(2-hydroxyphenyl)-4-quinazolinone (MJ-29) regarding anti-metastatic actions on human oral squamous cell carcinoma CAL 27 cells and on the verification of the underlying related molecular mechanisms of this event. MJ-29 concentration- and time-dependently caused a suppression of cell adhesive ability utilizing cell adhesion assay; it also inhibited the migration and invasion of CAL 27 cells using scratch wound closure and transwell invasion assays in a concentration-dependent response. Importantly, we confirmed that the applied concentration range of MJ-29 exhibited no dramatic influence of cytotoxicity on CAL 27 cells using the thiazolyl blue tetrazolium bromide assay. MJ-29 also attenuated the enzymatic activity of MMP-2 and MMP-9. Furthermore, we found that activation of their upstream protein kinases, by MJ-29, potentially exerted an inhibitory effect on the phosphorylated protein levels of extracellular regulated protein kinase 1/2, p38 and c-Jun N-terminal kinase 1/2, as well as serine/threonine kinase AKT by MJ-29 in CAL 27 cells. The expression of RAS and focal adhesion kinase was also down-regulated in MJ-29-treated CAL 27 cells. Collectively, these findings provide further evidence for the molecular signaling basis of the effects of MJ-29 on suppression of migration and invasion which might be useful as a therapeutic strategy to treat human oral cancer.

Bufalin increases sensitivity to AKT/mTOR-induced autophagic cell death in SK-HEP-1 human hepatocellular carcinoma cells.

Bufalin is the major component of Chan-Su (a traditional Chinese medicine, TCM) extracts from the venom of Bufo bufo gargarizan. In the present study, we investigated the pharmacological mechanisms of cell cycle arrest and autophagic cell death induced by bufalin in SK-HEP-1 human hepatocellular carcinoma cells in vitro. Bufalin inhibited cell survival by MTT assay and increased cell death by trypan blue exclusion assay in a concentration-dependent manner. In addition, bufalin induced G2/M phase arrest by reducing CDK1 activity. Bufalin triggered DNA fragmentation and apoptotic cell death in SK-HEP-1 cells by DNA gel electrophoresis, TUNEL and caspase-3 activity assay, while bufalin induced autophagic cell death by double-membrane vacuoles (transmission electron microscopy, TEM), acidic vesicular organelles (acridine orange staining) and cleavage of microtubule-associated protein 1 light chain 3 (LC3). Protein expression levels of cyclin A and B, CDK1, phospho-CDK1 (Thr161), Cdc25c, phospho-Cdc25c (Ser198), phospho-AKT (Thr308), phospho-AKT (Ser473), phospho­mTOR (Ser2481) were downregulated. In contrast, protein expression levels of the Chk1, Wee1, LC3-II, Beclin-1, Atg 5, Atg 7 and Atg 12 were upregulated in SK-HEP-1 cells after bufalin treatment. Inhibition of autophagy by 3-methyladenine (an inhibitor of class III phosphatidylinositol-3 kinase; 3-MA) or bafilomycin A1 (an inhibitor of the vacuolar proton pump of lysosomes and endosomes) reduced the effect of bufalin on cell viability and enhanced the effect of bufalin on apoptosis. In conclusion, bufalin triggered autophagic cell death and G2/M phase arrest through the AKT/mTOR signaling pathway in SK-HEP-1 cells. Our findings showed that bufalin may be potentially efficacious in the treatment of human hepatocellular carcinoma.

AKT serine/threonine protein kinase modulates bufalin-triggered intrinsic pathway of apoptosis in CAL 27 human oral cancer cells.

Bufalin has been reported to induce apoptosis in a variety of cancers but little is demonstrated in oral squamous cell carcinoma (OSCC) cells. The present study investigated the inhibition of proliferation, cell cycle arrest and apoptotic effects of bufalin in CAL 27 human oral cancer cells. Bufalin inhibited the growth of CAL 27 cells in a concentration-dependent manner and an IC50 value of bufalin was about 125 nM for 24 h treatment using the MTT assay. Moreover, the cell cycle distribution was arrested at the G0/G1 phase in CAL 27 cells after bufalin exposure. Upon bufalin stimulation, the expression of Bcl-2 was significantly decreased while that of cytochrome c, Apaf-1 and AIF was increased compared to the control group by western blot analysis. An increase in the expression of the active form of caspases was found in bufalin-treated cells, and the caspase activities were also elevated. Bufalin-triggered apoptosis was blocked by specific inhibitors of caspase-9 (z-LEHD-fmk) and caspase-3 (z-DEVD-fmk), respectively. In contrast, CAL 27 cells overexpressing constitutively active AKT (CAL 27/CA-AKT) were exposed to bufalin at different concentrations, and cell growth remained unchanged. Bufalin exhibited minimal apoptotic effects on CAL 27/CA-AKT cells. Taken together, bufalin induced G0/G1 phase arrest and provoked the intrinsic apoptotic pathway via AKT activation in CAL 27 cells. Our data suggest that bufalin could be potentially efficacious in the treatment of oral cancer in the future.

ERK-modulated intrinsic signaling and G(2)/M phase arrest contribute to the induction of apoptotic death by allyl isothiocyanate in MDA-MB-468 human breast adenocarcinoma cells.

Allyl isothiocyanate (AITC), a member of the isothiocyanate (ITC) family found in a constituent of cruciferous vegetables, possesses anticancer activity and induces apoptosis in various types of human cancer cell lines. However, no available information showed antitumor effects in human breast adenocarcinoma cells. The current study was focused on exploring the mechanisms underlying AITC-induced apoptosis in MDA-MB-468 human breast cancer cells in vitro. We found that AITC reduced the cell number and viability using trypan blue staining with the Countess Automated Cell Counter and the MTT assay, respectively. AITC also was found to induce apoptotic cell morphological changes by a contrast-phase microscope and cell cycle arrest at G(2)/M phase by flow cytometric assay in MDA-MB-468 cells. Intrinsic apoptosis-associated factors such as caspase-9 and caspase-3 activities were performed, and reactive oxygen species (ROS) production, loss of mitochondrial membrane potential (∆Ψm) occurred in AITC-treated MDA-MB-468 cells. AITC also stimulated mitochondria-related signaling, including p-Bcl-2 (Ser-70), cytochrome c and Apaf-1 in MDA-MB-468 cells. We found that the p-ERK signal was upregulated in AITC-treated cells. Importantly, NAC (a ROS scavenger) and U0126 (an ERK inhibitor) abolished AITC-reduced viability in MDA-MB-468 cells. AITC downregulated CDK1 activity and altered the expression of G(2)/M phase-modulated associated protein levels by western blotting in MDA-MB-468 cells. In summary, our findings demonstrated that AITC-promoted G2/M phase and AITC-triggered apoptosis correlate with the activation of phosphorylation of ERK in MDA-MB-468 cells. AITC is a potential agent for applcation in the treatment of human breast cancer.

Antioxidant, antinociceptive, and anti-inflammatory activities of Xanthii Fructus extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Xanthii seeds commonly called Cang-Erzi were used as a traditional Chinese medicine for treating sinusitis, headache due to rheumatism and skin pruritus. AIM OF THE STUDY: In order to evaluate the actions of this plant, studies were performed on antioxidant, antinociceptive, and anti-inflammatory activities. MATERIALS AND METHODS: The aqueous extract of Xanthii Fructus (AXF) was evaluated in mice for anti-inflammatory activity using carrageenan-induced hind paw edema model. The antinociceptive activity of AXF was evaluated by writhing and formalin tests. Antioxidant properties were assayed in terms of antioxidant activity by scavenging abilities on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing activity and liposome protection. In addition, the total phenolic content was determined with spectrophotometric method. RESULTS: AXF exhibited significant radical scavenging and reducing activity. And oral treatment with AXF elicited inhibitory activity on acetic acid effect and reduced the formalin effect at the late-phase. In the anti-inflammatory test, AXF inhibited the development of paw edema induced by λ-carrageenan (Carr). AXF decreased the paw edema at the fifth hour after Carr administration, and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the liver tissue and decreased the malondialdehyde (MDA) level in the edema paw. AXF decreased the level of serum nitric oxide (NO) and tumor necrosis factor (TNF)-α after Carr injection and AXF decreased the levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions in paw edema at the fifth hour. CONCLUSIONS: AXF shows antioxidant, antinociceptive, and anti-inflammatory activities, supporting the folkloric usage of the plant to treat various inflammatory diseases.

Hispolon suppresses SK-Hep1 human hepatoma cell metastasis by inhibiting matrix metalloproteinase-2/9 and urokinase-plasminogen activator through the PI3K/Akt and ERK signaling pathways.

Cancer metastasis is a primary cause of cancer death. Hispolon is an active phenolic compound of Phellinus linteus, a mushroom that has recently been shown to have antioxidant and anticancer activities. In this study, we first observed that hispolon exerted a dose-dependent inhibitory effect on invasion and motility, but not on adhesion, of the highly metastatic SK-Hep1 cells in the absence of cytotoxicity. Mechanistically, hispolon decreased the expression of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and urokinase-plasminogen activator (uPA) in a concentration-dependent manner. Hispolon also inhibited phosphorylation of extracellular signaling-regulating kinase1/2 (ERK1/2), phosphatidylinositol-3-kinase/serine/threonine protein kinase (or protein kinase B (PI3K/Akt), and focal adhesion kinase (FAK). Furthermore, treatment of SK-Hep1 cells with an inhibitor specific for ERK1/2 (PD98256) decreased the expression of MMP-2, and MMP-9. These results demonstrate that hispolon can inhibit the metastasis of SK-Hep1 cells by reduced expression of MMP-2, MMP-9, and uPA through the suppression of the FAK signaling pathway and of the activity of PI3K/Akt and Ras homologue gene family, member A (RhoA). These findings suggest that hispolon may be used as an antimetastatic agent.