Antitumor effects with apoptotic death in human promyelocytic leukemia HL‐60 cells and suppression of leukemia xenograft tumor growth by irinotecan HCl

Irinotecan HCl (CPT‐11) is an anticancer prodrug, but there is no available information addressing CPT‐11‐inhibited leukemia cells in in vitro and in vivo studies. Therefore, we investigated the cytotoxic effects of CPT‐11 in promyelocytic leukemia HL‐60 cells and in vivo and tumor growth in a leukemia xenograft model. Effects of CPT‐11 on HL‐60 cells were determined using flow cytometry, immunofluorescence staining, comet assay, real‐time PCR, and Western blotting. CPT‐11 demonstrated a dose‐ and time‐dependent inhibition of cell growth, induction of apoptosis, and cell‐cycle arrest at G0/G1 phase in HL‐60 cells. CPT‐11 promoted the release of AIF from mitochondria and its translocation to the nucleus. Bid, Bax, Apaf‐1, caspase‐9, AIF, Endo G, caspase‐12, ATF‐6b, Grp78, CDK2, Chk2, and cyclin D were all significantly upregulated and Bcl‐2 was down‐regulated by CPT‐11 in HL‐60 cells. Induction of cell‐cycle arrest by CPT‐11 was associated with changes in expression of key cell‐cycle regulators such as CDK2, Chk2, and cyclin D in HL‐60 cells. To test whether CPT‐11 could augment antitumor activity in vivo, athymic BALB/c^nu/nu nude mice were inoculated with HL‐60 cells, followed by treatment with either CPT‐11. The treatments significantly inhibited tumor growth and reduced tumor weight and volume in the HL‐60 xenograft mice. The present study demonstrates the schedule‐dependent antileukemia effect of CPT‐11 using both in vitro and in vivo models. CPT‐11 could potentially be a promising agent for the treatment of promyelocytic leukemia and requires further investigation. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 803–815, 2015.     

Safrole suppresses murine myelomonocytic leukemia WEHI‐3 cells in vivo,and stimulates macrophage phagocytosis and natural killer cell cytotoxicity in leukemic mice

Many anticancer drugs are obtained from phytochemicals and natural products. However, some phytochemicals have mutagenic effects. Safrole, a component of Piper betle inflorescence, has been reported to be a carcinogen. We have previously reported that safrole induced apoptosis in human oral cancer cells in vitro and inhibited the human oral tumor xenograft growth in vivo. Until now, there is no information addressing if safrole promotes immune responses in vivo. To evaluate whether safrole modulated immune function, BALB/c mice were intraperitoneally injected with murine myelomonocytic WEHI‐3 leukemia cells to establish leukemia and then were treated with or without safrole at 4 and 16 mg/kg. Animals were sacrificed after 2 weeks post‐treatment with safrole for examining the immune cell populations, phagocytosis of macrophages and the natural killer (NK) cells' cytotoxicity. Results indicated that safrole increased the body weight, and decreased the weights of spleen and liver in leukemic mice. Furthermore, safrole promoted the activities of macrophages phagocytosis and NK cells' cytotoxicity in leukemic mice when compared with untreated leukemic mice. After determining the cell marker population, we found that safrole promoted the levels of CD3 (T cells), CD19 (B cells) and Mac‐3 (macrophages), but it did not affect CD11b (monocytes) in leukemic mice. In conclusion, safrole altered the immune modulation and inhibited the leukemia WEHI‐3 cells in vivo. © 2011 Wiley Periodicals, Inc. Environ Toxicol 28:601–608, 2013.     

Genistein induces apoptosis in vitro and has antitumor activity against human leukemia HL‐60 cancer cell xenograft growth in vivo

Genistein, a major isoflavone compound in soybeans, has been shown to have biological activities including anti‐cancer activates. In the present, we investigated the anti‐leukemia activity of genistein on HL‐60 cells in vitro. The percentage of viable cell, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS), and Ca²⁺ production and the level of ΔΨ_m were measured by flow cytometric assay. Cell apoptosis and endoplasmic reticulum (ER) stress associated protein expressions were examined by Western blotting assay. Calpain 1, GRP78, and GADD153 expression were measured by confocal laser microscopy. Results indicated that genistein‐induced cell morphological changes, decreased the total viable cells, induced G₂/M phase arrest and DNA damage and fragmentation (cell apoptosis) in HL‐60 cells. Genistein promoted ROS and Ca²⁺ productions and decreased the level of ΔΨ_m in HL‐60 cells. Western blotting assay demonstrated that genistein increased ER stress‐associated protein expression such as IRE‐1α, Calpain 1, GRP78, GADD153, caspase‐7, caspase‐4, and ATF‐6α at 20‐50 μM treatment and increased apoptosis associated protein expression such as pro‐apoptotic protein Bax, PARP‐cleavage, caspase‐9, and ‐3, but decreased anti‐apoptotic protein such as Bcl‐2 and Bid in HL‐60 cells. Calpain 1, GRP78, and GADD153 were increased in HL‐60 cells after exposure to 40 μM of genistein. In animal xenografted model, mice were intraperitoneally injected with genistein (0, 0.2, and 0.4 mg/kg) for 28 days and the body weight and tumor volume were recorded. Results showed that genistein did not affect the body weights but significantly reduced the tumor weight in 0.4 mg/kg genistein‐treated group. Genistein also increased the expressions of ATF‐6α, GRP78, Bax, Bad, and Bak in tumor. In conclusion, genistein decreased cell number through G₂/M phase arrest and the induction of cell apoptosis through ER stress‐ and mitochondria‐dependent pathways in HL‐60 cells and suppressed tumor properties in vivo.     

Effects of diallyl trisulfide on induction of apoptotic death in murine leukemia WEHI‐3 cells in vitro and alterations of the immune responses in normal and leukemic mice in vivo

Diallyl trisulfide (DATS), a chemopreventive dietary constituent and extracted from garlic, has been shown to against cultured many types of human cancer cell liens but the fate of apoptosis in murine leukemia cells in vitro and immune responses in leukemic mice remain elusive. Herein, we clarified the actions of DATS on growth inhibition of murine leukemia WEHI‐3 cells in vitro and used WEHI‐3 cells to generate leukemic mice in vivo, following to investigate the effects of DATS in animal model. In in vitro study, DATS induced apoptosis of WEHI‐3 cells through the G0/G1 phase arrest and induction of caspase‐3 activation. In in vivo study DATS decreased the weight of spleen of leukemia mice but did not affect the spleen weight of normal mice. DATS promoted the immune responses such as promotions of the macrophage phagocytosis and NK cell activities in WEHI‐3 leukemic and normal mice. However, DATS only promotes NK cell activities in normal mice. DATS increases the surface markers of CD11b and Mac‐3 in leukemia mice but only promoted CD3 in normal mice. In conclusion, the present study indicates that DATS induces cell death through induction of apoptosis in mice leukemia WHEI‐3 cells. DATS also promotes immune responses in leukemia and normal mice in vivo. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1343–1353, 2015.     

Triptolide induced cell death through apoptosis and autophagy in murine leukemia WEHI‐3 cells in vitro and promoting immune responses in WEHI‐3 generated leukemia mice in vivo

Triptolide, a traditional Chinese medicine, obtained from Tripterygium wilfordii Hook F, has anti‐inflammatory, antiproliferative, and proapoptotic properties. We investigated the potential efficacy of triptolide on murine leukemia by measuring the triptolide‐induced cytotoxicity in murine leukemia WEHI‐3 cells in vitro. Results indicated that triptolide induced cell morphological changes and induced cytotoxic effects through G0/G1 phase arrest, induction of apoptosis. Flow cytometric assays showed that triptolide increased the production of reactive oxygen species, Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m), and activations of caspase‐8, ‐9, and ‐3. Triptolide increased protein levels of Fas, Fas‐L, Bax, cytochrome c, caspase‐9, Endo G, Apaf‐1, PARP, caspase‐3 but reduced levels of AIF, ATF6α, ATF6β, and GRP78 in WEHI‐3 cells. Triptolide stimulated autophagy based on an increase in acidic vacuoles, monodansylcadaverine staining for LC‐3 expression and increased protein levels of ATG 5, ATG 7, and ATG 12. The in vitro data suggest that the cytotoxic effects of triptolide may involve cross‐talk between cross‐interaction of apoptosis and autophagy. Normal BALB/c mice were i.p. injected with WEHI‐3 cells to generate leukemia and were oral treatment with triptolide at 0, 0.02, and 0.2 mg/kg for 3 weeks then animals were weighted and blood, liver, spleen samples were collected. Results indicated that triptolide did not significantly affect the weights of animal body, spleen and liver of leukemia mice, however, triptolide significant increased the cell populations of T cells (CD3), B cells (CD19), monocytes (CD11b), and macrophage (Mac‐3). Furthermore, triptolide increased the phagocytosis of macrophage from peripheral blood mononuclear cells (PBMC) but not effects from peritoneum. Triptolide promoted T and B cell proliferation at 0.02 and 0.2 mg/kg treatment when cells were pretreated with Con A and LPS stimulation, respectively; however, triptolide did not significant affect NK cell activities in vivo. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 550–568, 2017.     

Effects of Rutin on Lipid Profile in Hypercholesterolaemic Rats

Abstract: Rutin (3, 3′, 4′, 5, 7‐pentahydrohyflavone‐3‐rhamnoglucoside) is a flavonoid of the flavonol type. Rutin is found in many plants and is also an important dietary constituent of food and plant‐based beverages. Rutin has several pharmacological properties including antioxidant and cardioprotective activities. Also, it was identified that rutin is the major low‐density lipoprotein (LDL) antioxidant compound of mulberry in an in vitro study. The effects of rutin were tested by using it as a supplement in a high‐cholesterol diet. Male rats were fed a high‐cholesterol diet (1 ml/100 g) for 4 weeks with rutin (10 or 100 mg/kg) or rutin 100 mg/kg and lovastatin supplementation to study the hypocholesterolaemic effects of rutin on plasma lipid levels, hepatic enzyme activity, and liver tissue. Feeding the animals a high‐cholesterol diet resulted in marked hypercholesterolaemia and increased the serum level of LDL cholesterol (LDL‐C). Rutin (at 100 mg/kg) alone or in combination with lovastatin significantly reduced the levels of total cholesterol, and LDL‐C and also markedly decreased liver enzymes and weight in animals with a high‐cholesterol diet. Our findings show that 100 mg/kg of rutin alone or with lovastatin supplementation lowered liver weight and enzymes as well as plasma total cholesterol and LDL. The hepatic histopathological results reflect the correlation of rutin and lovastatin combination with both liver weight and the levels of plasma total cholesterol and LDL‐C. These results indicate that rutin in combination with lovastatin has increased anti‐hypercholesterolaemic effects in an animal model.     

Arsenic trioxide (As₂O₃) inhibits murine WEHI-3 leukemia in BALB/c mice in vivo

Arsenic trioxide (As₂O₃) is used clinically to treat acute promyelocytic leukemia (APL) and has activity in vitro for induction of apoptosis in several solid tumor cell lines. To investigate the potential therapeutic application of As₂O₃ for leukemia, we analyzed the effects of As₂O₃ on the WEHI‐3 cells‐induced orthotopic leukemia animal model in vivo in this study. We established the WEHI‐3 cells leukemia mice through the injection of murine WEHI‐3 cells into BALB/c mice, and they were then treated with As₂O₃ (0.9 and 4.5 mg kg^?1; p.o.) and/or combined with all‐trans‐retinoic acid (ATRA), (30 mg kg^?1; i.p.). The results indicated that (1) As₂O₃ alone or As₂O₃ combined with ATRA promoted the total survival rate of leukemia mice and these effects are dose‐dependent; (2) As₂O₃ did not affect the body weight but decreased the spleen weight; however, it did not affect liver weight; (3) As₂O₃ alone or As₂O₃ combined with ATRA increased the levels of CD3 and CD19, indicating that the differentiation of T and B cells were promoted; and (4) As₂O₃ alone or As₂O₃ combined with ATRA did not change the levels of Mac‐3 and CD11b markers, indicating that the differentiation of the precursor of macrophage were not inhibited. Based on these observations, As₂O₃ alone or As₂O₃ combined with ATRA have efficacious antileukemia activity in WEHI‐3 cells leukemia in vivo. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.     

Organoarsenic Roxarsone Promotes Angiogenesis In Vivo

Roxarsone, an organoarsenic feed additive, is widely used worldwide to promote animal growth. It has been found to exhibit a higher angiogenic index than As^III at lower concentrations and to promote angiogenic phenotype in human endothelial cell in vitro. Little research has focused on the potential angiogenic effect of roxarsone in vitro or in vivo. Here, we investigated the pro‐angiogenic effect of roxarsone in vivo. The effects of 0.1–10.0 μM roxarsone were tested in the rat endothelial cell Matrigel plug assay, chicken chorioallantoic membrane (CAM) model and MCF‐7 cell xenograft tumour model; 10 ng/mL vascular endothelial growth factor (VEGF) was used as a positive control and PBS as a negative control. Roxarsone significantly increased the volume, weight and haemoglobin content of the Matrigel plugs compared to PBS group (p < 0.05); 1.0 μM roxarsone exerted the most significant effects. H&E staining and CD31 immunochemistry revealed obviously more new vessels or capillary‐like structures in the plugs of the roxarsone and VEGF groups. Roxarsone significantly increased the numbers of primary/secondary vessels and area of vessels in the CAM assay and obviously increased tumour weight and volume in the xenograft model compared to PBS (p < 0.05). Histochemistry indicated local necrosis was observed at the centre of the xenograft tumours in the PBS and roxarsone groups, with less necrosis apparent in the VEGF‐treated tumours. The growth of endothelial cells and VEGF level was obviously affected at blockade of VEGF and its receptor Flt‐1/Flk‐1 by SU5416 or its antibody in vitro. This study demonstrates roxarsone promotes angiogenesis in vivo, and a VEGF/VEGFR mechanism may be involved.     

Mangiferin induces immune responses and evaluates the survival rate in WEHI‐3 cell generated mouse leukemia in vivo

Mangiferin is a naturally occurring polyphenol, widely distributed in Thymeraceae families, and presents pharmacological activity, including anti‐cancer activities in many human cancer cell lines. Mangiferin has also been reported to affect immune responses; however, no available information concerning the effects of mangiferin on immune reactions in leukemia mice in vivo. In the present study, we investigated the effects of mangiferin on leukemia WEHI‐3 cell generated leukemia BLAB/c mice. Overall, the experiments were divided into two parts, one part was immune responses experiment and the other was the survival rate experiment. The immune responses and survival rate study, 40 mice for each part, were randomly separated into five groups (N = 8): Group I was normal animals and groups II‐V WEHI‐3 cell generated leukemia mice. Group II mice were fed normal diet as a positive control; group III, IV, and V mice received mangiferin at 40, 80, and 120 mg/kg, respectively, by intraperitoneal injection every 2 days for 20 days. Leukocytes cell population, macrophage phagocytosis, and NK cell activities were analyzed by flow cytometry. Isolated splenocytes stimulated with lipopolysaccharide (LPS) and concanavalin A (Con A) were used to determine the proliferation of B and T cells, respectively, and subsequently were analyzed by flow cytometry. Results indicated that mangiferin significantly increased body weight, decreased the liver and spleen weights of leukemia mice. Mangiferin also increased CD3 T‐cell and CD19 B cell population but decreased Mac‐3 macrophage and CD11b monocyte. Furthermore, mangiferin decreased phagocytosis of macrophages from PBMC and peritoneal cavity at 40, 80, and 120 mg/kg treatment. However, it also increased NK cell activity at 40 and 120 mg/kg treatment. There were no effects on T and B cell proliferation at three examined doses. In survival rate studies, mangiferin significantly elevated survival rate at 40 and 120 mg/kg treatment of leukemia mice in vivo.     

Berberine impairs embryonic development in vitro and in vivo through oxidative stress‐mediated apoptotic processes

Berberine, an isoquinoline alkaloid isolated from several traditional Chinese herbal medicines, has been shown to suppress growth and induce apoptosis in some tumor cell lines. However, berberine has also been reported to attenuate H₂O₂‐induced oxidative injury and apoptosis. The basis for these ambiguous effects of berberine—triggering or preventing apoptosis—has not been well characterized to date. In the current investigation, we examined whether berberine exerts cytotoxic effects on mouse embryos at the blastocyst stage and affects subsequent embryonic development in vitro and in vivo. Treatment of blastocysts with berberine (2.5‐10 μM) induced a significant increase in apoptosis and a corresponding decrease in trophectoderm cell number. Moreover, the implantation success rate of blastocysts pretreated with berberine was lower than that of their control counterparts. Pretreatment with berberine was also associated with increased resorption of postimplantation embryos and decreased fetal weight. In an animal model, intravenous injection of berberine (2, 4, or 6 mg/kg body weight/d) for 4 days resulted in apoptosis of blastocyst cells and early embryonic developmental injury. Berberine‐induced injury of mouse blastocysts appeared to be attributable to oxidative stress‐triggered intrinsic apoptotic signaling processes that impaired preimplantation and postimplantation embryonic development. Taken together, our results clearly demonstrate that berberine induces apoptosis and retards early preimplantation and postimplantation development of mouse embryos, both in vitro and in vivo.     

Ameliorative effect of polyphenols from Padina boergesenii against ferric nitrilotriacetate induced renal oxidative damage: With inhibition of oxidative hemolysis and in vitro free radicals

The aim of this study was to evaluate the antioxidant activities of diethyl ether (DEE) and methanol (M) extracts from brown alga Padina boergesenii using in vitro and in vivo antioxidant assay, which may help to relate the antioxidant properties with the possible outline of its ameliorative effect. M extract showed higher radical scavenging activity through ferric reducing antioxidant power 139.11 µmol tannic acid equivalent/g; DPPH 71.32 ± 0.56%; deoxyribose radical 88.31 ± 0.47%, and total antioxidant activity 0.47 ± 0.02 mg ascorbic acid equivalents/g. Oxidative red blood cell (RBC) hemolysis inhibition rate was significantly higher in M extract (150 mg/kg body weight) in reference to total phenolic content (r = 0.935). Rats administered with DEE and M extracts (150 mg/kg body weight) for seven days before the administration of ferric nitrilotriacetate (9 mg of Fe/mg/kg bodyweight). Rats pretreated with extracts significantly changed the level of renal microsomal lipid peroxidation, glutathione, and antioxidant enzymes in post‐mitochondrial supernatant (P < 0.05). Ameliorative effect of extracts against renal oxidative damage was evident in rat kidney through changes in necrotic and epithelial cells. HPTLC technique has identified the presence of rutin with reference to retardation factor (R_f) in both the extracts. These findings support the source of polyphenols (rutin) from P. boergesenii had potent antioxidant activity; further work on isolation of bioactive compounds can be channeled to develop as a natural antioxidant. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 865–876, 2015.     

Biochanin A Inhibits Breast Cancer Tumor Growth in A Murine Xenograft Model

PURPOSE: Our objective was to determine the effect of the flavonoid biochanin A (BCA), administered alone or in combination with the flavonoids quercetin and epigallocatechin-3-gallate (EGCG), on the growth of human breast cancer MCF-7 cells in a murine xenograft animal model. MATERIALS AND METHODS: MCF-7 tumors were implanted into mice and groups of mice were treated with vehicle, BCA at 2 doses (5 or 15 mg/kg), quercetin and EGCG (5 mg/kg each), or BCA combined with quercetin and EGCG (5 mg/kg each). The flavonoids were injected once daily intraperitoneally, with treatment starting 4 weeks prior to cell inoculation. RESULTS: Treatment with 15 mg/kg of BCA or the mixture of the 3 flavonoids resulted in a reduction in tumor incidence. Tumor size in xenograft mice treated with 15 mg/kg BCA was significantly smaller than in the control group. Although quercetin/EGCG administration did not affect tumor size, treatment with the mixture of the 3 flavonoids at doses of 5 mg/kg produced similar effects as seen with 15 mg/kg BCA. CONCLUSIONS: Our findings indicate that BCA inhibits tumor growth in a xenograft animal model; BCA may represent a breast cancer preventive agent, either administered alone or in combination with other flavonoids.     

Effects of ochratoxin a on mouse oocyte maturation and fertilization,and apoptosis during fetal development

We previously reported that ochratoxin A (OTA), a mycotoxin found in many foods worldwide, causes nephrotoxicity, hepatotoxicity, and immunotoxicity, and is a risk factor for abnormal embryonic development. More specifically, OTA triggers apoptotic processes in the inner cell mass of mouse blastocysts, decreasing cell viability and embryonic development. In the current study, we investigated the deleterious effects of OTA on mouse oocyte maturation, in vitro fertilization (IVF), and subsequent pre‐ and postimplantation development both in vitro and in vivo. Notably, OTA significantly impaired mouse oocyte maturation, decreased IVF rates, and inhibited subsequent embryonic development in vitro. Preincubation of oocytes with OTA during in vitro maturation increased postimplantation embryonic resorption and decreased mouse fetal weight. In an in vivo animal model, provision of 1–10 μM OTA in the drinking water or intravenous injection of 1 or 2 mg/kg body weight of OTA decreased oocyte maturation and IVF, and had deleterious effects on early embryonic development. Importantly, preincubation of oocytes with a caspase‐3‐specific inhibitor effectively blocked these OTA‐triggered deleterious effects, suggesting that the embryonic injury induced by OTA is mediated via a caspase‐dependent apoptotic mechanism. Furthermore, OTA upregulated the levels of p53 and p21 in blastocyst cells derived from OTA‐pretreated oocytes, indicating that such cells undergo apoptosis via p53‐, p21‐, and caspase‐3‐dependent regulatory mechanisms. This could have deleterious effects on embryonic implantation and fetal survival rates, as seen in our animal models. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 724–735, 2016.     

消癌平注射液联合紫杉醇对人卵巢癌SK-OV-3细胞增殖及裸鼠异位移植瘤生长的作用

目的 研究消癌平（XAP）注射液和紫杉醇（PTX）联合应用对人卵巢癌SK-OV-3细胞增殖及裸鼠异位移植瘤的抑制作用。方法 将生长至对数期的人卵巢癌SK-OV-3细胞分为6组：对照组、紫杉醇组（10 nmol/L）、消癌平注射液低、高剂量组（20、80 μl/ml）、消癌平注射液低、高剂量联合组（PTX 10 nmol/L+XAP 20 μl/ml、PTX 10 nmol/L+XAP 80 μl/ml）,各组分别加入药物干预24 h或48 h后,MTT法测定并计算细胞存活率。将36只雌性荷人卵巢癌细胞SK-OV-3的异位移植瘤裸鼠随机分为6组,包括对照组（G1：生理盐水）、紫杉醇组（G2：PTX 10 mg/kg）、消癌平注射液低、高剂量组（G3：XAP 20 ml/kg、G4：XAP 50 ml/kg）、低剂量联合组（G5：PTX 10 mg/kg+XAP 20 ml/kg）以及高剂量联合组（G6：PTX 10 mg/kg+XAP 50 ml/kg）,每组6只。各治疗组予相应药物治疗18 d,观察记录小鼠一般情况、体重、肿瘤体积,并计算抑瘤率。结果 SK-OV-3细胞体外实验结果显示,与对照组相比,消癌平注射液、低剂量联合组和高剂量联合组的SK-OV-3细胞存活率均显著降低（P<0.05或P<0.01）,且联合用药组与紫杉醇组相比,也有显著差异（P<0.05）,并呈现剂量和时间依赖性。裸鼠异位移植瘤实验结果显示,高剂量联合组的抑瘤率明显高于对照组和紫杉醇组,差异有统计学意义（P<0.05）。结论 消癌平注射液和紫杉醇联用对人卵巢癌细胞SK-OV-3裸鼠异位移植瘤的抑制具有协同作用（P<0.05）。     

Antitumor effect of folate-targeted liposomal doxorubicin in KB tumor-bearing mice after intravenous administration

The effect of folate-targeted liposomal doxorubicin (FTL-Dox) has been well characterized in folate receptor (FR) overexpressing tumors in vitro, particularly in KB human carcinoma cells. However, there are few studies evaluating the in vivo efficacy of FTL-Dox in KB murine xenograft models. In this study, we investigated the antitumor activity of FTL-Dox injected intravenously in mice bearing KB tumors. Folate ligands comprising of folate-polyethyleneglycol-distearoylphosphatidylethanolamine (FA-PEG-DSPE) were synthesized with different MW PEG. To design an optimum FTL-Dox formulation for therapeutic studies, we prepared various FTLs and characterized their in vitro targeting and in vivo tissue biodistribution. Mice were administered a single intravenous injection of free Dox, nontargeted PEGylated liposomal Dox (PL-Dox), or FTL-Dox. FTLs and PLs accumulated similarly in tumor tissue, despite FTLs’ faster clearance from circulation. Mice treated with FTL-Dox 20?mg/kg had a slightly greater tumor growth inhibition and almost a 50% increase in life span than mice receiving PL-Dox 20?mg/kg (P?=?0.0121; log-rank test). We conclude that FTLs administered systemically have the potential to enhance the delivery of anticancer drugs in vivo; however, their removal by FR expressing normal tissues may have to be blocked if the benefits of tumor targeting are to be realized.     

Chronic Treatment with Quercetin does not Inhibit Angiotensin‐Converting Enzyme In Vivo or In Vitro

Abstract: The precise mechanisms explaining the anti‐hypertensive effects produced by quercetin are not fully known. Here, we tested the hypothesis that chronic quercetin treatment inhibits the angiotensin‐converting enzyme (ACE). We examined whether quercetin treatment for 14 days reduces in vivo responses to angiotensin I or enhances the responses to bradykinin in anaesthetised rats. We measured the changes in systemic arterial pressure induced by angiotensin I in doses of 0.03–10 μg/kg, by angiotensin II in doses of 0.01–3 μg/kg, and to bradykinin in doses of 0.03–10 μg/kg in anaesthetised rats pre‐treated with vehicle (controls), or daily quercetin 10 mg/kg intraperitoneally for 14 days, or a single i.v. dose of captopril 2 mg/kg. Plasma ACE activity was determined by a fluorometric method. Plasma quercetin concentrations were assessed by high performance liquid chromatography. Quercetin treatment induced no significant changes in the hypertensive responses to angiotensin I and angiotensin II, as well in the hypotensive responses to bradykinin (all p > 0.05). Conversely, as expected, a single dose of captopril inhibited the hypertensive responses to angiotensin I and potentiated the bradykinin responses (all p < 0.01), while no change was found in the vascular responses to angiotensin II (all p > 0.05). In addition, although we found significant amounts of quercetin in plasma samples (mean = 206 ng/mL), no significant differences were found in plasma ACE activity in rats treated with quercetin compared with those found in the control group (50 ± 6 his‐leu nmol/min/mL and 40 ± 7 his‐leu nmol/min/mL, respectively; p > 0.05). These findings provide strong evidence indicating that quercetin does not inhibit ACE in vivo or in vitro and indicate that other mechanisms are probably involved in the antihypertensive and protective cardiovascular effects associated with quercetin.     

5‐Fluorouracil combined with apigenin enhances anticancer activity through mitochondrial membrane potential (ΔΨm)‐mediated apoptosis in hepatocellular carcinoma

The development of chemoresistance may reduce the efficacy of chemotherapeutic drugs for treating hepatocellular carcinoma (HCC). In the present study, the effects of apigenin on intensifying the chemosensitivity of HCC cells and an HCC xenograft model in response to 5‐fluorouracil (5‐FU) were investigated. Sub‐toxic concentrations of apigenin (4 μmol/L) significantly enhanced the cytotoxicity of 5‐FU (100 μg/mL) in HCC cells. In vivo, combined treatment with apigenin (20 mg/kg, five times/week for 3 weeks) and 5‐FU (20 mg/kg for 5 consecutive days) significantly inhibited the growth of HCC xenograft tumours. Annexin V–propidium iodide dual staining assays, terminal deoxyribonucleotidyl transferase‐mediated dUTP–digoxigenin nick end‐labelling assays and western blotting analysis were used to confirm the synergistic effects of apigenin and 5‐FU on HCC apoptosis. Coincubation of HCC cells with apigenin and 5‐FU increased levels of reactive oxygen species (ROS), which was followed by a decrease in the mitochondrial membrane potential (ΔΨm). In addition, combined triggered the mitochondrial apoptotic pathway, as indicated by decreased Bcl‐2 expression and loss of ΔΨm, with significant activation of caspase 3 and poly(ADP‐ribose) polymerase. The present study is the first to demonstrate that apigenin may potentiate the cytotoxicity of 5‐FU in HCC via inhibition of ROS‐mediated drug resistance and concurrent activation of the mitochondrial pathways of apoptosis.     

Antitumor Activity of Folate Receptor-Targeted Liposomal Doxorubicin in a KB Oral Carcinoma Murine Xenograft Model

Purpose. The expression of folate receptor (FR) is amplified in many types of human cancers. Previously, FR-targeted liposomal doxorubicin (f-L-DOX) has been shown to exhibit superior and selective cytotoxicity against FR(+) tumor cells in vitro compared to nontargeted liposomal doxorubicin (L-DOX). This study further investigates f-L-DOX for its antitumor efficacy in vivo using a murine tumor xenograft model. Methods. F-L-DOX composed of DSPC/cholesterol/PEG-DSPE/folate-PEG-DSPE (65:31:3.5:0.5, mole/mole) was prepared by polycarbonate membrane extrusion followed by remote loading of DOX. Athymic mice on a folate-free diet were engrafted with FR(+) KB cells. Two weeks later, these mice were treated with f-L-DOX, L-DOX, or free DOX in a series of six injections (given intraperitoneally on every fourth day at 10 mg/kg DOX) and monitored for tumor growth and animal survival. The plasma clearance profiles of the DOX formulations and the effect of dietary folate on plasma folate concentration were also analyzed. Results. Plasma folate level remained in the physiologic range relative to that in humans. F-L-DOX exhibited an extended systemic circulation time similar to that of L-DOX. Mice that received f-L-DOX showed greater tumor growth inhibition and a 31% higher (p < 0.01) increase in lifespan compared to those that received L-DOX. Meanwhile, free DOX given at the same dose resulted in significant toxicity and was less effective in prolonging animal survival. Conclusions. FR-targeted liposomes are a highly efficacious vehicle for in vivo delivery of anticancer agents and have potential application in the treatment of FR(+) solid tumors.