Polysaccharide from spore of Ganoderma lucidum ameliorates paclitaxel-induced intestinal barrier injury: Apoptosis inhibition by reversing microtubule polymerization.

Side effects of chemotherapy are burning questions for physicians and patients involved in cancers. Ganoderma lucidum is a widely consumed traditional Chinese medicine and edible mushroom with multiple functional properties. The present study aims to investigate the potential of polysaccharides from spore of G. lucidum (SGP) on small intestinal barrier function recovery against paclitaxel (PTX) challenge in a breast cancer mice model and IEC-6 cell line. The 4T1 tumor-bearing mice were treated with PTX together with four-week daily oral administration of SGP. Results indicated that combination of PTX and SGP reversed body weight lost and remolded the histology of small intestine, accompanied with promoted proliferation but suppressed apoptosis in intestinal cells. Intestinal barrier function was enhanced by the combination as indicated by reduced endotoxemia and the up-regulation of tight junction proteins, including Zonula occludens-1 (ZO-1), E-cadherin, ß-catenin and Occludin. The protection of SGP was further confirmed in IEC-6 cells affected by PTX in vitro. The combination treatment prevented PTX-induced apoptosis in IEC-6 by inhibiting microtubule polymerization, and the aforementioned tight junction proteins were also upregulated. These findings suggest a promising protective effect of SGP against small intestinal barrier injury caused by PTX, highlighting its clinical implication against the chemotherapy side effects.

Evaluating the relationship between cell viability and volatile organic compound production following DMSO treatment of cultured human cells.

Methylsulfinylmethane (dimethyl sulfoxide; DMSO) is widely used in clinical treatment and bioresearch. Moreover, there is bioconversion between methylsulfanylmethane (dimethyl sulfide; DMS), DMSO, and methylsulfonylmethane (DMSO2) in mammalian metabolism. Due to the real-time detection limits for volatile compounds, most research has focused on DMSO2 as a stable byproduct of DMSO. Therefore, details about the production of DMS as a byproduct of DMSO metabolism remain to be elucidated. Here, we report the characterization of trace-level volatile organic compounds (VOCs) produced following DMSO treatment of cultured human cells using an ultrasensitive vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS). Using this approach, 24 h after DMSO treatment we detected 16.9 and 21 parts per billion by volume (ppbv) DMS in the atmosphere above the cells (headspace) within HeLa and 293T tissue culture flasks, respectively. When simultaneously exposed to 50 nM paclitaxel (PTX), 17.6 and 22.3 ppbv DMS were detected in the headspace of HeLa and 293T culture flasks, respectively. Nevertheless, at doses of PTX more or less than 50 nM, the detectable levels of DMS were reduced to as low as 8.4 ppbv. Our experimental results demonstrate that by co-administering 5 to 10 nM PTX with DMSO, it is possible to moderate the production of DMS considerably. However, at higher doses of PTX, increased apoptosis was observed that likely contributed to higher DMS production by cells.

Estrogen modulation properties of mangiferin and quercetin and the mangiferin metabolite norathyriol.

Mango fruit contain many bioactive compounds, some of which are transcription factor regulators. Estrogen receptor alpha (ERα) and beta (ERß) are two regulators of gene transcription that are important in a variety of physiological processes and also in diseases including breast cancer. We examined the ability of the mango constituents quercetin, mangiferin, and the aglycone form of mangiferin, norathyriol, to activate both isoforms of the estrogen receptor. Quercetin and norathyriol decreased the viability of MCF-7 breast cancer cells whereas mangiferin had no effect on MCF-7 cells. We also determined that quercetin and mangiferin selectively activated ERα whereas norathyriol activated both ERα and ERß. Despite quercetin, mangiferin and norathyriol having similar polyphenolic structural motifs, only norathyriol activated ERß, showing that bioactive agents in mangoes have very specific biological effects. Such specificity may be important given the often-opposing roles of ERα and ERß in breast cancer proliferation and other cellular processes.

Vitexin 6, a novel lignan, induces autophagy and apoptosis by activating the Jun N-terminal kinase pathway.

Previous studies have reported that vitexins induce cytotoxic effects. In the present study, we investigate a new native lignan vitexin 6 (VB6) in vitro to determine the molecular mechanism underlying its cytotoxicity. We screened and cultured several tumor cell lines and subsequently analyzed VB6 cytotoxicity against 14 different tumor cell lines using a 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The expression of proteins that regulate apoptosis and autophagy was determined using western blot analysis. VB6 showed an excellent cytotoxic effect against various cancer cell lines in vitro. It induced apoptosis and autophagy of cancer cells. VB6-induced apoptosis showed a time-dependent and concentration-dependent relationship with cleaved poly (ADP-ribose) polymerase, cleaved caspase-3, Bax upregulation, and Bcl-2 downregulation. The levels of Beclin-1 and LC3-II, which are markers for cell autophagy, gradually increased after VB6 treatment. Jun N-terminal kinase (JNK) phosphorylation was increased after VB6 treatment, accompanied by upregulation of P-Bcl-2 and P-C-Jun expression. Cotreatment with a JNK inhibitor significantly decreased VB6-induced cell death and downregulated P-Bcl-2, and cleaved PARP and Beclin-1 expression. The new native lignan VB6 inhibits cancer cell proliferation by activating the JNK pathway. We believe that VB6 could be a valuable chemotherapeutic drug after further evaluation.

Akebia saponin PA induces autophagic and apoptotic cell death in AGS human gastric cancer cells.

In this study, we investigated the anticancer mechanism of akebia saponin PA (AS), a natural product isolated from Dipsacus asperoides in human gastric cancer cell lines. It was shown that AS-induced cell death is caused by autophagy and apoptosis in AGS cells. The apoptosis-inducing effect of AS was characterized by annexin V/propidium (PI) staining, increase of sub-G1 phase and caspase-3 activation, while the autophagy-inducing effect was indicated by the formation of cytoplasmic vacuoles and microtubule-associated protein 1 light chain-3 II (LC3-II) conversion. The autophagy inhibitor bafilomycin A1 (BaF1) decreased AS-induced cell death and caspase-3 activation, but caspase-3 inhibitor Ac-DEVD-CHO did not affect LC3-II accumulation or AS-induced cell viability, suggesting that AS induces autophagic cell death and autophagy contributes to caspase-3-dependent apoptosis. Furthermore, AS activated p38/c-Jun N-terminal kinase (JNK), which could be inhibited by BaF1, and caspase-3 activation was attenuated by both SB202190 and SP600125, indicating that AS-induced autophagy promotes mitogen-activated protein kinases (MAPKs)-mediated apoptosis. Taken together, these results demonstrate that AS induces autophagic and apoptotic cell death and autophagy plays the main role in akebia saponin PA-induced cell death.

Hydroxytyrosol promotes superoxide production and defects in autophagy leading to anti-proliferation and apoptosis on human prostate cancer cells.

Hydroxytyrosol, an important polyphenolic compound found in olive oil, has shown anti-tumor activity both in vitro and in vivo. However, effects of hydroxytyrosol on prostate cancer are largely unkown. We found that hydroxytyrosol preferentially reduces the viability of human prostate cancer cells (PC-3, DU145) compared to an immortalized non-malignant prostate epithelial cell line (RWPE-1). Exposure of PC-3 cells to 80 µmol/L hydroxytyrosol resulted in significant increases in both superoxide production and activation of apoptosis. These increases were accompanied by mitochondrial dysfunction, defects in autophagy, and activation of MAP kinases. Moreover, N-acetylcysteine (NAC), an efficient reactive oxygen species (ROS) scavenger, was able to reverse the hydroxytyrosol-induced effects of cell viability loss, defects in autophagy, and activation of apoptosis. This evidence suggests that ROS play a vital role in the loss of PC-3 cell viability. However, MAPK inhibitors including U0126 (for Erk1/2), SB203580 (for p38MAPK) and SP600125 (for JNK) did not decrease hydroxytyrosol-induced growth inhibition, suggesting that these kinases may not be required for the growth inhibitory effect of hydroxytyrosol. Moreover, addition of ROS scavengers (i.e. NAC, catalase, pyruvate, SOD) in the growth media can prevent hydroxytyrosol induced cell viability loss, suggesting that extracellular ROS (superoxide and hydrogen peroxide) facilitate the anti-proliferation effect of hydroxytyrosol in prostate cancer cells. The present work firstly shows that hydroxytyrosol induces apoptotic cell death and mitochondrial dysfunction by generating superoxide in PC-3 cells. This research presents preliminary evidence on the in vitro chemopreventive effect of hydroxytyrosol, and will contribute to further investigation of hydroxytyrosol as an anti-cancer agent.

Glaucocalyxin A induces apoptosis in human leukemia HL-60 cells through mitochondria-mediated death pathway.

Glaucocalyxin A (GLA) is a biologically active ent-kauranoid diterpenoid isolated from Rabdosia japonica var. glaucocalyx, a traditional Chinese medicinal herb, which has been shown to inhibit tumor cell proliferation. However, the mechanism underlying GLA-induced cytotoxicity remains unclear. In this study, we focused on the effect of GLA induction on apoptosis, the mitochondria-mediated death pathway and the accumulation of reactive oxygen species (ROS) in human leukemia cells (HL-60). GLA could induce a dose-dependent apoptosis in HL-60 cells as characterized by cell morphology, DNA fragmentation, activation of caspase-3, -9 and an increased expression ratio of Bax/Bcl-2. The mitochondrial membrane potential (Δψ(m)) loss and cytochrome c release from mitochondria to cytosol were observed during the induction. Moreover, GLA caused a time- and dose-dependent elevation of intracellular ROS level in HL-60 cells, and N-acetyl-l-cysteine (NAC, a well-known antioxidant) could block GLA-induced ROS generation and apoptosis. These data suggest that GLA induces apoptosis in HL-60 cells through ROS-dependent mitochondrial dysfunction pathway.

Herbal medicine Shakuyaku-kanzo-to reduces paclitaxel-induced painful peripheral neuropathy in mice.

OBJECTIVES: Paclitaxel is widely used in cancer chemotherapy for the treatment of solid tumors such as breast, ovarian and lung cancer. However, it sometimes induces moderate to severe muscle pain, and impairs the patients' quality of life. An appropriate method for relieving this pain is not well established. Shakuyaku-kanzo-to, a herbal medicine, is known to relieve menstrual pain, muscle spasm, and muscle pain, and its effectiveness is expected. To ascertain the effectiveness of Shakuyaku-kanzo-to on paclitaxel-induced pain, we investigated the effects of Shakuyaku-kanzo-to and its constituent herbal medicines in a mouse model. METHODS: Seven-week-old male ddY mice were used. To make a mouse model of paclitaxel-induced pain, different single, intraperitoneally injected doses of this drug were tested in various groups of mice, and the optimal dose was determined. To estimate the effects of Shakuyaku-kanzo-to, the constituent herbal medicines Shakuyaku and Kanzo, and loxoprofen sodium as a non-steroidal anti-inflammatory drug on paclitaxel-induced pain, mechanical allodynia and hyperalgesia of the hind paw were assessed. RESULTS: Paclitaxel administered at a dose of 10mg/kg or more produced allodynia and hyperalgesia; the time courses were similar to those of pain after paclitaxel administration in cancer patients. Shakuyaku-kanzo-to significantly relieved the allodynia and hyperalgesia induced by paclitaxel (10mg/kg). Shakuyaku and Kanzo inhibited the allodynia and hyperalgesia to some extent, but not significantly, while loxoprofen sodium was without effects. CONCLUSIONS: A single administration of paclitaxel (10mg/kg) produced allodynia and hyperalgesia in mice, suggesting that it could be used as an animal model resembling the painful conditions observed in humans medicated with this drug. Using this model, Shakuyaku-kanzo-to was shown to relieve paclitaxel-induced painful peripheral neuropathy.

Anticancer drugs designed by mother nature: ancient drugs but modern targets.

Nuclear factor-kappaBeta (NF-kappaBeta) is a transcription factor that is activated in response to various inflammatory stimuli such as cytokines, growth factors, hormones, mitogens, carcinogens, chemotherapeutic agents, viral products, eukaryotic parasites, endotoxin, fatty acids, metals, radiation, hypoxia, and psychological, physical, oxidative, and chemical stresses. In addition, constitutively active NF-kappaBeta is frequently encountered in a wide variety of tumors. Furthermore, NF-kappaBeta activation has been shown to regulate the expression of over 400 genes involved in cellular transformation, proliferation, inflammation, viral replication, antiapoptosis, angiogenesis, invasion and metastasis, oxidative stress, and osteoclastogenesis. Therefore, because of the critical role NF-kappaBeta plays in the pathogenesis of cancer, specific inhibitors of this factor are being sought. Agents that prevent cancer or inflammation have been found to suppress NF-kappaBeta activation. Numerous reports indicate that ancient plants and their components are potent as NF-kappaB inibitors. However, ancient medicine such as traditional Chinese medicine, Kampo, Ayurveda requires rediscovery in light of our current knowledge of allopathic (modern) medicine for the therapeutic and preventive purpose. In this review, we present evidence that numerous agents identified from fruits and vegetables can interfere with NF-kappaBeta pathway. The structure of drugs and their relationship with NF-kappaBeta inhibitory activity is discussed.

St. John's wort attenuates irinotecan-induced diarrhea via down-regulation of intestinal pro-inflammatory cytokines and inhibition of intestinal epithelial apoptosis.

Diarrhea is a common dose-limiting toxicity associated with cancer chemotherapy, in particular for drugs such as irinotecan (CPT-11), 5-fluouracil, oxaliplatin, capecitabine and raltitrexed. St. John's wort (Hypericum perforatum, SJW) has anti-inflammatory activity, and our preliminary study in the rat and a pilot study in cancer patients found that treatment of SJW alleviated irinotecan-induced diarrhea. In the present study, we investigated whether SJW modulated various pro-inflammatory cytokines including interleukins (IL-1beta, IL-2, IL-6), interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) and intestinal epithelium apoptosis in rats. The rats were treated with irinotecan at 60 mg/kg for 4 days in combination with oral SJW or SJW-free control vehicle at 400 mg/kg for 8 days. Diarrhea, tissue damage, body weight loss, various cytokines including IL-1beta, IL-2, IL-6, IFN-gamma and TNF-alpha and intestinal epithelial apoptosis were monitored over 11 days. Our studies demonstrated that combined SJW markedly reduced CPT-11-induced diarrhea and intestinal lesions. The production of pro-inflammatory cytokines such as IL-1beta, IFN-gamma and TNF-alpha was significantly up-regulated in intestine. In the mean time, combined SJW significantly suppressed the intestinal epithelial apoptosis induced by CPT-11 over days 5-11. In particular, combination of SJW significantly inhibited the expression of TNF-alpha mRNA in the intestine over days 5-11. In conclusion, inhibition of pro-inflammatory cytokines and intestinal epithelium apoptosis partly explained the protective effect of SJW against the intestinal toxicities induced by irinotecan. Further studies are warranted to explore the potential for STW as an agent in combination with chemotherapeutic drugs to lower their dose-limiting toxicities.

St. John's Wort modulates the toxicities and pharmacokinetics of CPT-11 (irinotecan) in rats.

CPT-11 is a DNA topoisomerase I inhibitor for the therapy of colorectal cancer, whereas St. John's Wort (Hypericum perforatum, SJW) is a widely used herbal anti-depressant. This study aimed to investigate the effects of co-administered SJW on the toxicities and pharmacokinetics of CPT-11 and the underlying mechanisms. The body weight loss, gastrointestinal and hematological toxicities induced by CPT-11, and the pharmacokinetic parameters of CPT-11 were evaluated in rats pretreated with SJW or vehicle. Rats treated with CPT-11 alone experienced rapid decrease in body weight, whereas co-administration of SJW with CPT-11 resulted in lesser body weight loss. The gastrointestinal and hematological toxicities following CPT-11 injection were both alleviated in the presence of SJW. The rat pharmacokinetics of both CPT-11 and its metabolite SN-38 were significantly altered in presence of SJW. In conclusion, co-administered SJW significantly ameliorated the toxicities induced by CPT-11. The protective effect of SJW may be partially due to pharmacokinetic interaction between CPT-11 and SJW.

Ajoene, an experimental anti-leukemic drug: mechanism of cell death.

The organosulfur compound ajoene, a constitutent of garlic, has been shown to induce apoptosis in a leukemic cell line as well as in blood cells of a leukemic patient. The mechanisms of action of ajoene, however, are unknown. The present study aims to characterize the molecular events leading to ajoene-triggered apoptosis. We show here that ajoene (20 microM) leads to a time-dependent activation of caspase-3-like activity as well as to the proteolytic processing of procaspase-3 and -8. Activation of caspases was necessary for ajoene-induced apoptosis since the broad-range caspase inhibitor zVAD-fmk completely abrogated ajoene-mediated DNA fragmentation. Although the initiator caspase-8 was activated, the CD95 death receptor was not involved in death signaling since the HL-60 clone used was shown to express a functionally inactive CD95 receptor. Furthermore, ajoene induced the release of cytochrome c, which was not inhibited by zVAD-fmk indicating that cytochrome c release precedes caspase activation. Ajoene also led to a dissipation of the mitochondrial transmembrane potential. Overexpression of Bcl-x(L) clearly diminished ajoene-induced caspase activation as well as apoptosis. These results indicate that apoptosis in leukemia cells triggered by ajoene is based on the activation of a mitochondria-dependent caspase cascade which includes also the activation of the initiator caspase-8.

Ethyl acetate extract of the stem bark of Cudrania tricuspidata induces apoptosis in human leukemia HL-60 cells.

Apoptosis is now widely accepted as playing a role in tumorigenesis. An effective compound which can kill tumors via apoptotic pathway appears to be a relevant strategy to suppress various human tumors. The ethyl acetate extract from the stem bark of Cudrania tricuspidata (EACT) showed dose- and time-dependent cytotoxic effects on human leukemia HL-60 cells. DNA fragmentation and morphological changes, accompanied by condensed and fragmented nuclei, were observed in the cells cultured for 6 hr with EACT. These results suggest that the cytotoxicity of the crude extract from Cudrania tricuspidata against HL-60 cells is due to apoptosis.

Modulation of VP-16 cytotoxicity by carboplatin and 41.8 degrees C hyperthermia.

PURPOSE: To study in vitro the effect of carboplatin and/or hyperthermia in relation to etoposide (VP-16) cytotoxicity in L929 cells. METHODOLOGY/RESULTS: Cell survival assays demonstrated that the addition of 41.8 degrees C (x60 min) hyperthermia and carboplatin to VP-16 produced an antagonistic effect relative to VP-16 cytotoxicity in L929 cells; administering carboplatin and hyperthermia 24 h before VP-16 reduced this drug resistance; administering carboplatin and hyperthermia 48 h before VP-16, however, produced a supra-additive cytotoxicity. In order to gain insight into the molecular basis for these observations, we investigated the effect of hyperthermia and/or carboplatin on the stress protein GRP78, which is known to affect VP-16 cytotoxicity. Results obtained were consistent with the hypothesis that carboplatin and hyperthermia perturbation of NAD + pools results in down-regulation of GRP78 with subsequent modulation of VP-16 cytotoxicity. To further explicate these results we studied G-361 as a control cell line that had significantly higher pretreatment NAD+ levels, which were not affected by carboplatin and/or hyperthermia. This cell line did not exhibit a down-regulation of GRP78 or modulation of VP-16 cytotoxicity as a function of carboplatin and hyperthermia. CONCLUSIONS: These data taken collectively, demonstrate a sequence effect (regarding the aforementioned antineoplastic agents), and provide a framework for future studies directed at the therapeutic optimization of the sequential application of carboplatin, hyperthermia, and VP-16.

Two new constituents of Isodon excisus and their evaluation in an apoptosis inhibition assay.

Investigation of the whole plant of Isodon excisus resulted in the isolation of two new apoptosis inhibitors (1 and 2). Compounds 1 and 2 inhibited etoposide-induced apoptosis in U937 cells with IC50 values of 10.2 and 52.4 microg/mL, respectively. The structures of 1 and 2 were determined by spectral data interpretation.

Protective effects of kampo medicines and baicalin against intestinal toxicity of a new anticancer camptothecin derivative, irinotecan hydrochloride (CPT-11), in rats.

In clinical use, irinotecan hydrochloride (CPT-11; 7-ethyl-10-[4-(piperidino)-1-piperidino]carbonyloxycamptothecin), a novel antitumor agent, causes a relatively high incidence of severe forms of diarrhea. We investigated whether baicalin, an inhibitor of beta-glucuronidase, which deconjugates the glucuronide of the active metabolite of CPT-11, SN-38 (7-ethyl-10-hydorxycamptothecin), and Japanese herbal medicines (Kampo medicines) which contain baicalin can ameliorate CPT-11-induced intestinal toxicity in rats. CPT-11 (60 mg/kg i.v. once daily for 4 consecutive days) induced intestinal toxicity characterized by diarrhea, loss of body weight, anorexia and disruption of intestinal epithelium. Treatment with baicalin (25 mg/kg p.o. twice daily) or Kampo medicines (TJ-14 and TJ-114; 1 g/kg p.o. twice daily) from the day before to 4 or 10 days after the start of CPT-11 administration resulted in significantly decreased weight loss, improved anorexia and delayed onset of diarrheal symptoms. Histological examination revealed that Kampo medicine-treated animals had less damage to the intestinal epithelium and that damage was repaired more rapidly than in control rats. These results suggest that the prophylactic use of Kampo medicines (TJ-14 and TJ-114) may be of value against CPT-11-induced intestinal toxicity.

Presence of a receptor for the active component of Iscador in ascites fluid of tumour bearing mice.

Tumour bearing mice exhibit a specific "receptor" in the ascites fluid which binds with the active component isolated from Iscador. This "receptor" was found to be a protein which inhibited the cytotoxicity of Iscador and its isolated active component at low concentration. The receptor protein was also found in the sonicates of tumour cells which are susceptible to the action of Iscador but not in lymphocytes which were not susceptible to Iscador or its isolated active component. The receptor was separated on a Sephadex G-50 column. Activity was lost upon heat denaturation and dialysis.

Role of thiol agents in protecting against the toxicity of helenalin in tumor-bearing mice.

Helanalin, a sesquiterpene lactone antineoplastic agent, is toxic at therapeutic doses in murine tumors. The toxicity has been assumed to be correlated with the binding of the drug to cellular thiol groups. Studies were undertaken to increase the intracellular level of GSH in the liver, kidney and other tissues to eliminate the toxicity of helenalin in vivo. Combination of helenalin 8 mg/kg/day i.p.) with L-cysteine (100 mg/kg/day), beta-mercaptoethanolamine (20 mg/kg/day), 18-beta-glycyrrhetinic acid (15 mg/kg/day), or 4,4'-diaminodiphenylsulfone (10 mg/kg/day) afforded improvement in survival of mice bearing P-388 lymphocytic leukemia. However, other thiol-elevating agents, anti-oxidants, intracellular buffering agents, and cardiac treatment drugs were not effective. Hydrocortisone, Cortef, treatment with helenalin afforded improvement in life expectancy. Reduced glutathione (GSH) and non-protein sulfhydryl (NPS) levels were not reduced in the liver, kidney, or circulating red blood cells (rbc) by helenalin treatment. After three days treatment of mice with helenalin, GSH levels were reduced and NPS levels elevated in P-388 tumor cells. Administration of L-cysteine, beta-mercaptoethanolamine, 4,4'-diaminodiphenylsulfone, or 18-beta-glycyrrhetinic acid alone caused no alteration in liver GSH but elevated NPS levels; P388 cell GSH and NPS levels were lowered. Combination of any of these agents, after three days, with helenalin afforded increases in P-388 cell GSH and NPS levels. This data would suggest that helenalin toxicity is not related to the lowering of GSH or NPS levels in critical tissues of mice.