Ginseng-derived nanoparticles reprogram macrophages to regulate arginase-1 release for ameliorating T cell exhaustion in tumor microenvironment.

BACKGROUND: Lines of evidence indicated that, immune checkpoints (ICs) inhibitors enhanced T cell immune response to exert anti-tumor effects. However, T cell exhaustion has been so far a major obstacle to antitumor immunotherapy in colorectal cancer patients. Our previous studies showed that ginseng-derived nanoparticles (GDNPs) inhibited the growth of various tumors by reprograming tumor-associated macrophages (TAMs) and downregulated the ICs expression on T cells in tumor microenvironment (TME), but the underlying effector mechanisms remained unclear. METHODS: The correlation between arginase-1 (ARG1) and T cells was computed based on the colorectal cancer patients in TCGA database. In vitro, we observed that GDNPs reprogrammed TAMs inhibited ARG1 release and ultimately ameliorated T cell exhaustion according to several techniques including WB, PCR, ELISA and flow cytometry. We also used an in vivo MC38 tumor-bearing model and administered GDNPs to assess their anti-tumor effects through multiple indices. The mechanism that GDNPs improved T cell exhaustion was further clarified using the bioinformatics tools and flow cytometry. RESULTS: GDNPs reprogramed TAMs via reducing ARG1 production. Moreover, normalized arginine metabolism ameliorated T cell exhaustion through mTOR-T-bet axis, resulting in reduced ICs expression and enhanced CD8+ T cells expansion. CONCLUSIONS: By regulating the mTOR-T-bet axis, GDNPs reprogramed macrophages to regulate ARG1 release, which further ameliorated T cell exhaustion in TME. These findings provided new insights into comprehending the mechanisms underlying the mitigation of T cell exhaustion, which may facilitate the development of innovative therapeutic strategies in the field of cancer treatment.

Ginseng-derived nanoparticles potentiate immune checkpoint antibody efficacy by reprogramming the cold tumor microenvironment.

Cold tumor microenvironment (TME) marked with low effector T cell infiltration leads to weak response to immune checkpoint inhibitor (ICI) treatment. Thus, switching cold to hot TME is critical to improve potent ICI therapy. Previously, we reported extracellular vesicle (EV)-like ginseng-derived nanoparticles (GDNPs) that were isolated from Panax ginseng C.A. Mey and can alter M2 polarization to delay the hot tumor B16F10 progression. However, the cold tumor is more common and challenging in the real world. Here, we explored a combinatorial strategy with both GDNPs and PD-1 (programmed cell death protein-1) monoclonal antibody (mAb), which exhibited the ability to alter cold TME and subsequently induce a durable systemic anti-tumor immunity in multiple murine tumor models. GDNPs enhanced PD-1 mAb anti-tumor efficacy in activating tumor-infiltrated T lymphocytes. Our results demonstrated that GDNPs could reprogram tumor-associated macrophages (TAMs) to increase CCL5 and CXCL9 secretion for recruiting CD8+ T cells into the tumor bed, which have the synergism to PD-1 mAb therapy with no detected systemic toxicity. In situ activation of TAMs by GDNPs may broadly serve as a facile platform to modulate the suppressive cold TME and optimize the PD-1 mAb immunotherapy in future clinical application.

Identification of a selective inhibitor of IDH2/R140Q enzyme that induces cellular differentiation in leukemia cells.

BACKGROUND: IDH2/R140Q mutation is frequently detected in acute myeloid leukemia (AML). It contributes to leukemia via accumulation of oncometabolite D-2-HG. Therefore, mutant IDH2 is a promising target for AML. Discovery of IDH2 mutant inhibitors is in urgent need for AML therapy. METHODS: Structure-based in silico screening and enzymatic assays were used to identify IDH2/R140Q inhibitors. Molecular docking, mutant structure building and molecular dynamics simulations were applied to investigate the inhibitory mechanism and selectivity of CP-17 on IDH2/R140Q. TF-1 cells overexpressed IDH2/R140Q mutant were used to study the effects of CP-17 on cellular proliferation and differentiation, the wild-type TF-1 cells were used as control. The intracellular D-2-HG production was measured by LC-MS. The histone methylation was evaluated with specific antibodies by western blot. RESULTS: CP-17, a heterocyclic urea amide compound, was identified as a potent inhibitor of IDH2/R140Q mutant by in silico screening and enzymatic assay. It exhibits excellent inhibitory activity with IC50 of 40.75 nM against IDH2/R140Q. More importantly, it shows poor activity against the wild-type IDH1/2, resulting in a high selectivity of over 55 folds, a dramatic improvement over previously developed inhibitors such as AGI-6780 and Enasidenib. Molecular simulations suggested that CP-17 binds to IDH2/R140Q at the allosteric site within the dimer interface through extensive polar and hydrophobic interactions, locking the enzyme active sites in open conformations with abolished activity to produce D-2-HG. Cellular assay results demonstrated that CP-17 inhibits intracellular D-2-HG production and suppresses the proliferation of TF-1 erythroleukemia cells carrying IDH2/R140Q mutant. Further, CP-17 also restores the EPO-induced differentiation that is blocked by the mutation and decreases hypermethylation of histone in the TF-1(IDH2/R140Q) cells. CONCLUSIONS: These results indicate that CP-17 can serve as a lead compound for the development of inhibitory drugs against AML with IDH2/R140Q mutant. Video abstract.

Arnebiae Radix prevents atrial fibrillation in rats by ameliorating atrial remodeling and cardiac function.

ETHNOPHARMACOLOGICAL RELEVANCE: Arnebiae Radix, a common herbal medicine in China, is often utilized to treat blood-heat syndrome and has been reported to exert an effect on the heart. AIM OF THE STUDY: The combination of acetylcholine (Ach) and CaCl2 has been widely used to induce atrial fibrillation (AF) in animals. However, whether Arnebiae Radix displays any preventive action on Ach-CaCl2 induced AF in rats remains uncertain. In our study, we attempted to investigate the protective effects of Arnebiae Radix on Ach-CaCl2 induced AF compared to amiodarone, which was employed as the positive control. MATERIALS AND METHODS: To establish the AF model, SD rats were treated with a mixture of 0.1 mL/100 g Ach-CaCl2 (60 µg/mL Ach and 10 mg/mL CaCl2) by tail vein injection for 7 days. Rats were also given a gavage of Arnebiae Radix (0.18 g/mL) one week before or concurrently with the establishment of the AF model. At the end of the experimental period, the induction, duration and timing of AF were monitored using electrocardiogram recordings. Left atrial tissues were stained to observe the level of fibrosis. Electrophysiological measurements were used to examine atrial size and function. RESULTS: In Ach-CaCl2-induced AF rats, Arnebiae Radix decreased AF induction, duration and susceptibility to AF. In addition, Arnebiae Radix significantly reduced atrial fibrosis and inhibited atrial enlargement induced by Ach-CaCl2. Moreover, there was an apparent improvement in cardiac function in the Arnebiae Radix-treated group. CONCLUSIONS: Our findings indicate that Arnebiae Radix treatment can attenuate Ach-CaCl2-induced atrial injury and serve as an effective therapeutic strategy for the treatment of AF in the future.

Ginseng-derived nanoparticles alter macrophage polarization to inhibit melanoma growth.

BACKGROUND: It is unclear whether plant-derived extracellular vesicles (EVs) can mediate interspecies communication with mammalian cells. Tumor-associated macrophages (TAMs) display a continuum of different polarization states between tumoricidal M1 phenotype and tumor-supportive M2 phenotypes, with a lower M1/M2 ratio correlating with tumor growth, angiogenesis and invasion. We investigated whether EVs from ginseng can alter M2-like polarization both in vitro and in vivo to promote cancer immunotherapy. METHODS: A novel EVs-liked ginseng-derived nanoparticles (GDNPs) were isolated and characterized from Panax ginseng C. A. Mey. Using GDNPs as an immunopotentiator for altering M2 polarized macrophages, we analyzed associated surface markers, genes and cytokines of macrophages treated with GDNPs. Mice bearing B16F10 melanoma were treated with GDNPs therapy. Tumor growth were assessed, and TAM populations were evaluated by FACS and IF. RESULTS: GDNPs significantly promoted the polarization of M2 to M1 phenotype and produce total reactive oxygen species, resulting in increasing apoptosis of mouse melanoma cells. GDNP-induced M1 polarization was found to depend upon Toll-like receptor (TLR)-4 and myeloid differentiation antigen 88 (MyD88)-mediated signaling. Moreover, ceramide lipids and proteins of GDNPs may play an important role in macrophage polarization via TLR4 activation. We found that GDNPs treatment significantly suppressed melanoma growth in tumor-bearing mice with increased presence of M1 macrophages detected in the tumor tissue. CONCLUSIONS: GDNPs can alter M2 polarization both in vitro and in vivo, which contributes to an antitumor response. The polarization of macrophages induced by GDNPs is largely dependent on TLR4 and MyD88 signalling. GDNPs as an immunomodulator participate in mammalian immune response and may represent a new class of nano-drugs in cancer immunotherapy.

Herbal Medicine AC591 Prevents Oxaliplatin-Induced Peripheral Neuropathy in Animal Model and Cancer Patients.

Oxaliplatin is clinically compelling because of severe peripheral neuropathy. The side effect can result in dosage reductions or even cessation of chemotherapy, and no effective treatments are available. AC591 is a standardized extract of Huangqi Guizhi Wuwu decoction, an herbal formula recorded in "Synopsis of the Golden Chamber" for improving limb numbness and pain. In this study, we investigated whether AC591 could protect against oxaliplatin-induced peripheral neuropathy. To clarify it, a rat model of oxaliplatin-induced peripheral neuropathy was established, and neuroprotective effect of AC591 was studied. Our results showed that pretreatment with AC591 reduced oxaliplatin-induced cold hyperalgesia, mechanical allodynia as well as morphological damage of dorsal root ganglion. Microarray analysis indicated the neuroprotective action of AC591 depended on the modulation of multiple molecular targets and pathways involved in the downregulation of inflammation and immune response. Moreover, AC591 enhanced the antitumor activity of oxaliplatin to some extent in Balb/c mice bearing CT-26 carcinoma cells. The efficacy of AC591 is also investigated in 72 colorectal cancer patients. After four cycles of treatment, the percentage of grades 1-2 neurotoxicity in AC591-treated group (n = 36) was 25%, whereas in the control group the incidence was 55.55% (P < 0.01) (n = 36). No significant differences in the tumor response rate between the two groups were found. These evidences suggested that AC591 can prevent oxaliplatin-induced neuropathy without reducing its antitumor activity, and may be a promising adjuvant to alleviate sensory symptoms in clinical practice.

Gut microbiota drives the attenuation of dextran sulphate sodium-induced colitis by Huangqin decoction.

The gut microbiota, including probiotics and pathogenic microorganisms, is involved in ulcerative colitis (UC) by regulating pathogenic microorganisms and the production of intestinal mucosal antibodies. Huangqin decoction (HQD), a traditional Chinese formula chronicled in the Shanghan lun, has been recognized as an effective drug for UC, owing to its anti-inflammatory and anti-oxidative properties. In the present study, we investigated whether HQD ameliorates dextran sulphate sodium (DSS)-induced colitis through alteration of the gut microbiota. We found that HQD significantly inhibited colitis, alleviating the loss of body weight, disease activity index, colon shortening, tissue injury, and inflammatory cytokine changes induced by DSS treatment. Principal component analysis and principal co-ordinate analysis showed an obvious difference among the groups, with increased diversity in the DSS and DSS+HQD groups. Linear discriminant analysis effect size was used to determine differences between the groups. The relative abundance of Lactococcus was higher in the DSS+HQD group than in the DSS group, whereas Desulfovibrio and Helicobacter were decreased. Furthermore, the protective effect of HQD was attenuated only in antibiotic-treated mice. In conclusion, our results suggest that HQD could ameliorate DSS-induced inflammation through alteration of the gut microbiota.

Cantharidin Overcomes Imatinib Resistance by Depleting BCR-ABL in Chronic Myeloid Leukemia.

Cantharidin (CTD) is an active compound isolated from the traditional Chinese medicine blister beetle and displayed anticancer properties against various types of cancer cells. However, little is known about its effect on human chronic myeloid leukemia (CML) cells, including imatinib-resistant CML cells. The objective of this study was to investigate whether CTD could overcome imatinib resistance in imatinib-resistant CML cells and to explore the possible underlying mechanisms associated with the effect. Our results showed that CTD strongly inhibited the growth of both imatinib-sensitive and imatinib-resistant CML cells. CTD induced cell cycle arrest at mitotic phase and triggered DNA damage in CML cells. The ATM/ATR inhibitor CGK733 abrogated CTD-induced mitotic arrest but promoted the cytotoxic effects of CTD. In addition, we demonstrated that CTD downregulated the expression of the BCR-ABL protein and suppressed its downstream signal transduction. Real-time quantitative PCR revealed that CTD inhibited BCR-ABL at transcriptional level. Knockdown of BCR-ABL increased the cell-killing effects of CTD in K562 cells. These findings indicated that CTD overcomes imatinib resistance through depletion of BCR-ABL. Taken together, CTD is an important new candidate agent for CML therapy.

Bacillus as a potential diagnostic marker for yellow tongue coating.

Observation of tongue coating, a foundation for clinical diagnosis and treatment in traditional Chinese medicine (TCM), is a major indicator of the occurrence, development, and prognosis of disease. The biological basis of tongue diagnosis and relationship between the types and microorganisms of tongue coating remain elusive. Thirteen chronic erosive gastritis (CEG) patients with typical yellow tongue coating (YTC) and ten healthy volunteers with thin white tongue coating (WTC) were included in this study. Patients were provided a 2-course targeted treatment of a herbal medicine Ban Xia Xie Xin decoction, traditionally prescribed for CEG patients with YTC, to evaluate the relationship between tongue coating microbiota and diagnosis of CEG with typical YTC. The tongue coating segregation structure was determined using Illumina Miseq sequencing of the V4-V5 region of the 16S ribosomal RNA gene. Bacillus was significantly observed only in CEG patients with YTC, but not in patients who received the decoction. YTC (n = 22) and WTC (n = 29) samples were collected for bacterial culturing to illustrate the relationship between Bacillus and YTC. The Bacillus positivity rate of YTC samples was 72.7%; Bacillus was not observed in WTC samples. In conclusion, Bacillus was strongly associated with YTC.

Protective effects of Huangqin Decoction against ulcerative colitis and associated cancer in mice.

Individuals with ulcerative colitis (UC) are at a high risk for developing colorectal cancer (CRC). Huangqin Decoction (HQD), a traditional Chinese medicinal formula chronicled in the Shang Han Lun, is commonly used to treat gastrointestinal symptoms. However, experimental evidence for supporting the clinical practice is lacking. This study used modern biomedical approaches to investigate the protective/preventive effects of HQD in dextran sulfate sodium (DSS)-induced acute/chronic UC and azoxymethane (AOM)/DSS-induced CRC in mice. HQDs were prepared in 4 different ways: HQD-1 and HQD-2 were prepared in boiling water, whereas HQD-3 and HQD-4 were prepared in heated ethanol (70%). For HQD-1 and HQD-3, the 4 constituent herbs were processed together, whereas for HQD-2 and HQD4, these herbs were processed individually and then combined. The mice were administered 9.1 g/kg HQD via oral gavage daily. HQD-1 significantly inhibited DSS-induced acute UC, whereas HQD-3 and HQD-4 exhibited mild ameliorative effects; but HQD-2 had no protective effect and resulted in a higher mortality rate. This higher mortality rate may be due to the greater abundance of baicalein and wogonin in HQD-2 than HQD-1. Furthermore, HQD-1 protected against DSS-induced chronic UC and significantly inhibited AOM/DSS-induced CRC in mice. HQD-1 also inhibited the production of inflammatory cytokines and increased antioxidant capacity both in chronic DSS and AOM/DSS treated mice. Overall, HQD-1 inhibits the development of acute/chronic colitis and prevents colitis-associated CRC, possibly by inhibiting inflammation and preventing oxidative stress induced cellular damage.

Yupingfeng Pulvis Regulates the Balance of T Cell Subsets in Asthma Mice.

Background. Yupingfeng Pulvis (HFBP) had played an active role in many diseases, especially respiratory tract infections. Exploring the possible prevention mechanism of HFBP may provide new ideas in clinical applications for this well-known herbal formula. Purpose. To study the possible mechanisms of therapy effect of HFBP on asthma mice via regulating the balance of Tregs and Th17 cells. Method. The female BALB/c mice were divided into five groups: control group, model group, prednisone (5.5 mg/kg) group, and 22 g/kg HFBP and 44 g/kg HFBP groups. Ovalbumin was used to make the asthma model of mice; the drug was ig administered daily after atomization for consecutive 15 d. The mice were killed after the last administration. The paraffin-embedded tissue sections of the lungs were stained by H&E. Tregs and Th17 cells in bronchoalveolar lavage fluid were detected by flow cytometry. IL-4, TGF-ß, and TNF-α in the serum were detected by ELISA assay. Results. HFBP could alleviate the inflammation in the lung tissue of mice, decrease the proportion of Th17 cells, and increase the proportion of Treg cells in bronchoalveolar lavage fluid. HFBP could decrease IL-4 and TNF-α level and increase TGF-ß level in blood. Conclusion. HFBP could treat the asthma through impacting the balance of Th17 cells and Treg cells as well as the levels of related inflammatory cytokines in asthma mice.

Ancient Chinese Formula Qiong-Yu-Gao Protects Against Cisplatin-Induced Nephrotoxicity Without Reducing Anti-tumor Activity.

Cisplatin is a highly effective anti-cancer chemotherapeutic agent; however, its clinical use is severely limited by serious side effects, of which nephrotoxicity is the most important. In this study, we investigated whether Qiong-Yu-Gao (QYG), a popular traditional Chinese medicinal formula described 840 years ago, exhibits protective effects against cisplatin-induced renal toxicity. Using a mouse model of cisplatin-induced renal dysfunction, we observed that pretreatment with QYG attenuated cisplatin-induced elevations in blood urea nitrogen and creatinine levels, ameliorated renal tubular lesions, reduced apoptosis, and accelerated tubular cell regeneration. Cisplatin-mediated elevations in tumor necrosis factor alpha (TNF-α) mRNA, interleukin-1 beta (IL-1ß) mRNA, and cyclooxygenase-2 (COX-2) protein in the kidney were also significantly suppressed by QYG treatment. Furthermore, QYG reduced platinum accumulation in the kidney by decreasing the expression of copper transporter 1 and organic cation transporter 2. An in vivo study using implanted Lewis lung cancer cells revealed that concurrent administration of QYG and cisplatin did not alter the anti-tumor activity of cisplatin. Our findings suggest that the traditional Chinese medicinal formula QYG inhibits cisplatin toxicity by several mechanisms that act simultaneously, without compromising its therapeutic efficacy. Therefore, QYG may be useful in the clinic as a protective agent to prevent cisplatin-induced nephrotoxicity.

Banxia xiexin decoction protects against dextran sulfate sodium-induced chronic ulcerative colitis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Banxia Xiexin decoction (BXD), one of a traditional Chinese medicine chronicled in Shang Han Lun, is commonly used to treat gastroenteritis, ulcerative colitis and diarrhea. In our study, we used current biomedical approaches to investigate the therapeutic efficacy of BXD and possible protective mechanism involved in inhibiting dextran sulfate sodium (DSS)-induced chronic ulcerative colitis model. MATERIALS AND METHODS: Chronic DSS colitis was induced in C57BL/6 male mice by three cycles of 5 days of 2% DSS in drinking water, alternating with 5 days of normal water, totaling 30 days. In BXD group, the mice were administered at a dose of 8.7g/kg BXD for 5 days before and during DSS treatment via oral gavage per day. Mice in vehicle group and DSS group were given orally the same volume of drinking water, instead. Body weight, stool characters and hematochezia were observed everyday. The colorectal tissues were used to detect levels of TNF-α, IL-4, IL-10, IL-1ß, IL-17, IL-23 and MPO by ELISA or qRT-PCR. The expression of COX-2, 8-Oxoguanine and Nrf2 were examined by IHC, and p-p65 was examined by western blotting. ThOD and the content of MDA were measured according to kits respectively. RESULTS: BXD significantly protected against DSS-induced chronic ulcerative colitis by amelioration of body weight loss, DAI and histology score. The level of TNF-α, IL-1ß, IL-17, IL-23, COX-2 and p-p65 were decreased significantly, while the level of IL-10 improved with the treatment of BXD. MDA, MPO and 8-Oxoguanine were decreased, meanwhile SOD activity and Nrf2 expression were elevated significantly by BXD. CONCLUSIONS: BXD possesses the potential of anti-inflammation and anti-oxidation to treat colitis. The protective mechanism of BXD may involve in inhibition of NF-κBp65 activation and increasement of Nrf2 expression in colorectums of mice.

Elemene injection induced autophagy protects human hepatoma cancer cells from starvation and undergoing apoptosis.

Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anticancer effects against a broad spectrum of tumors. In an in vivo experiment, we found that apatinib, a tyrosine kinase inhibitor that selectively inhibits VEGFR2, combined with elemene injection (Ele) for the treatment of H22 solid tumor in mice resulted in worse effectiveness than apatinib alone. Moreover, Ele could protect HepG2 cells from death induced by serum-free starvation. Further data on the mechanism study revealed that Ele induced protective autophagy and prevented human hepatoma cancer cells from undergoing apoptosis. Proapoptosis effect of Ele was enhanced when proautophagy effect was inhibited by hydroxychloroquine. Above all, Ele has the effect of protecting cancer cells from death either in apatinib induced nutrient deficient environment or in serum-free induced starvation. A combination of elemene injection with autophagy inhibitor might thus be a useful therapeutic option for hepatocellular carcinoma.

Problems and prospects of current studies on the microecology of tongue coating.

Tongue diagnosis in traditional Chinese medicine (TCM) assesses the health by investigation of tongue coating. The science and technology of tongue coating analysis have become a significant issue for modernization of TCM. The relationship between microecology of tongue coating and TCM was relevant to the syndrome differentiation in TCM, such as the cold/hot syndrome may exhibit different specific microbiota patterns in the tongue coating. This article provides a review on the microbiota research of tongue coating.

The aqueous extract of Lycopus lucidus Turcz ameliorates streptozotocin-induced diabetic renal damage via inhibiting TGF-ß1 signaling pathway.

PURPOSE: Renal fibrosis characterized by accumulation of extracellular matrix protein results in chronic renal diseases including diabetic nephropathy. Transforming growth factor ß1 (TGF-ß1) signaling pathway plays a key role in mediating renal fibrosis. Hence, agents that antagonize TGF-ß signaling could be candidate for kidney disease therapy. METHODS: We established renal fibrosis model both in vitro with fibroblast cells treated with rhTGF-ß1 and streptozocin(STZ)-induced diabetic nephropathy rats model in vivo and evaluated the effect of the aqueous extract of Lycopus lucidus Turcz, the blood-circulation-promoting Chinese herb, on diabetic nephropathy and investigated the mechanism of action. RESULTS: We found that Lycopus suppressed rhTGF-ß1-induced Smad2 and ERK1/2 activation, down-regulated the expression of TGF-ßRI, TGF-ßRII, Smad4 and Smad7 in SV40 MES13 cells without inhibiting cell viability. In vivo, lycopus inhibited Smad2 phosphorylation, reduced mRNA level of TGF-ß1, ameliorated expansion of the mesangial area in glomerular tissue and reduced the levels of Scr and BUN of serum and total-SOD (superoxide dismutase) activity in STZ-induced diabetic rats. CONCLUSION: Lycopus is a novel inhibitor of renal fibrosis by blocking TGF-ß signaling pathway and possess a protective effect on renal damage of STZ-induced diabetic nephropathy in rats.

Mailuoning prevents high-glucose-mediated human umbilical vein endothelial cells apoptosis.

OBJECTIVE: To investigated the role of Mailuoning in the prevention of high-glucose-mediated cell apoptosis in human umbilical vein endothelial cells (HUVEC) and the mechanisms involved. METHODS: MTT assay was used to investigate cell viability, western blot was used to investigate protein expression, and flow cytometric detection technology was used to detect cell apoptosis. RESULTS: Exposure of HUVEC to high glucose (50 mM) significantly suppressed cell viability and increased cell apoptosis compared with normal glucose (11 mM) (all P < 0.05). However, Mailuoning prevented high-glucose-induced HUVEC apoptosis in dose-dependent manner. Further studies indicated that Mailuoning suppressed high-glucose-induced p38 mitogen-activated protein kinase phosphorylation, but had no effect on extracellular signal-regulated kinase 1/2 and Akt phosphorylation. CONCLUSION: Mailuoning can prevent high-glucose-induced HUVEC apoptosis by suppressing p38 activation.

5,7-Dihydroxyflavone Enhances the Apoptosis-Inducing Potential of TRAIL in Human Tumor Cells via Regulation of Apoptosis-Related Proteins.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising candidate for the treatment of cancer, because it preferentially induces apoptosis in numerous cancer cells with little or no effect on normal cells. 5,7-Dihydroxyflavone is a dietary flavonoid commonly found in many plants. Here we show that the combined treatment with 5,7-dihydroxyflavone and TRAIL at subtoxic concentrations induced strong apoptotic response in human hepatocarcinoma HepG2 cells, acute leukemia Jurkat T cells, and cervical carcinoma HeLa cells. We further investigated the mechanisms by which 5,7-dihydroxyflavone augments TRAIL-induced apoptosis in HepG2 cells. 5,7-Dihydroxyflavone up-regulated the expression of pro-apoptotic protein Bax, attenuated the expression of anti-apoptotic proteins Bcl-2, Mcl-1, and IAPs, and reduced the phosphorylation levels of Akt and STAT3, weakening the anti-apoptotic signals thus facilitating the process of apoptosis. Moreover, 5,7-dihydroxyflavone and TRAIL were well tolerated in mice, and the combination of 5,7-dihydroxyflavone and TRAIL reduced tumor burden in vivo in a HepG2 tumor xenograft model. Interestingly, 5,7-dihydroxyflavone-mediated sensitization to TRAIL-induced cell death was not observed in normal human hepatocytes L-O2. These results suggest that the 5,7-dihydroxyflavone in combination with TRAIL might be used for cancer prevention and/or therapy.

Toosendanin induces apoptosis through suppression of JNK signaling pathway in HL-60 cells.

Toosendanin (TSN), a triterpenoid isolated from Melia toosendan Sieb. et Zucc., has been found to suppress proliferation and induce apoptosis in a variety of human cancer cells. However, the mechanism how TSN induces apoptosis remains poorly understood. In this study, we examined the effects of TSN on the growth, cell cycle arrest, induction of apoptosis and the involved signaling pathway in human promyelocytic leukemia HL-60 cells. Proliferation of HL-60 cells was inhibited in a dose-dependent manner with the IC(50 (48 h)) of 28 ng/mL. The growth inhibition was due primarily to the S phase arrest and cell apoptosis. Cell apoptosis induced by TSN was confirmed by Annexin V-FITC/propidium iodide staining. The increase of the pro-apoptotic protein Bax, cleaved PARP and caspase-3, and the decrease of anti-apoptotic protein Bcl-2 were observed. Western blot analysis indicated that TSN inhibits the CDC42/MEKK1/JNK pathway. Taken together, our study suggested, for the first time, that the pro-apoptotic effects of TSN on HL-60 cells were mediated through JNK signaling pathway.

Chinese medicine formula "Weikang Keli" induces autophagic cell death on human gastric cancer cell line SGC-7901.

Weikang Keli (constitutes of Root of Codonopsis pilosula, Rhizoma Atractylodis Macrocephalae, Rhizoma Curcumae Aeruginosae, Rhizoma Pinelliae, Actinidia chinensis Planch, and Rhodiola rosea) is a well known Chinese herbal formula for gastric cancer therapy in clinical treatment. However, the detailed molecular mechanisms involved are still not fully understood. In this study, we found that Weikang Keli could induce patterns of autophagy in SGC-7901 cells, including intracellular vacuole formation, microtubule-associated protein 1 light chain 3 (LC3) conversion. Hoechst 33258 staining and Western blot analysis of apoptosis-related proteins showed that WK induced SGC-7901 cell death was not through apoptosis. In vivo study also revealed that i.g. administration of Weikang Keli once a day for 25 days could significantly reduce tumor volumes by about 50%. Collectively, the current data indicated that Weikang Keli induced gastric cancer cell death by autophagy effects.