Thrombopoietin ameliorates doxorubicin-induced toxicities in H9c2 myocardiocytes by inhibiting oxidative stress through the SIRT1/p38 MAPK signaling pathway

Objective:To explore whether thrombopoietin can exert a protective effect against doxorubicin-induced cardiotoxicity by modulating the sirtuin 1(SIRT1)signaling pathway.Methods:H9c2 cell viability was determined by CCK-8 and cardiomyocyte apoptosis was detected by TUNEL assay.The protein expressions of SIRT1 and p38 MAPK were measured by Western blot.RT-qPCR was also used to determine SIRT1 mRNA expression.In addition,intracellular reactive oxygen species levels and antioxidant enzyme activities were evaluated.Results:Thrombopoietin treatment reversed doxorubicin-induced decline in H9c2 cell viability.It also increased SIRT1 and decreased p-p38 MAPK protein expressions.In addition,thrombopoietin significantly attenuated doxorubicin-induced apoptosis and oxidative stress,and enhanced antioxidant enzyme activities.However,silencing SIRT1 abrogated the protective effects of thrombopoietin,as evidenced by reduced cell viability and increased oxidative stress and reactive oxygen species levels.Conclusions:Thrombopoietin alleviates doxorubicin-induced cardiomyocyte injury by reducing oxidative stress and apoptosis via the SIRT1/p38 MAPK pathway.However,its protective effects need to be further verified in animal tests.

Charcoal Nanoparticles as a Delivery System for Doxorubicin and Sorafenib in Treatment of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is the most common type of liver cancer and one of the leading causes of cancer-related death worldwide. Advanced HCC displays strong resistance to chemotherapy, and traditional chemotherapy drugs do not achieve satisfactory therapeutic efficacy. The delivery of therapeutic compounds to the target site is a major challenge in the treatment of many diseases. Objective: This study aims to evaluate activated charcoal nanoparticles as a drug delivery system for anticancer agents (Sorafenib and Doxorubicin) in Hepatocellular Cancer Stem Cells. Method: The percent efficiency of entrapment (% EE) of the doxorubicin and sorafenib entrapped onto the activated charcoal was obtained by determining the free doxorubicin and sorafenib concentration in the supernatant-prepared solutions. Then the characterizations of nanoparticles were formed by determination of the particle size distribution, zeta potential, and polydispersity index (PDI). The anticancer activity of activated Charcoal, Doxorubicin-ACNP, sorafenib-ACNP, free doxorubicin, and free sorafenib solutions was measured based on cell viability percentage in HepG2 cell lines (ATCC-CCL 75). In vitro RBC’s toxicity of Doxorubicin/sorafenib loaded charcoal was estimated by hemolysis percentage. Results: The synthesized Doxorubicin-ACNP and Sorafenib-ACNP were evaluated and their physiochemical properties were also examined. Essentially, the percent Efficiency of Entrapment (EE %) was found to be 87.5% and 82.66% for Doxorubicin-ACNP and Sorafenib-ACNP, respectively. The loading capacity was 34.78% and 24.31% for Doxorubicin-ACNP and Sorafenib-ACNP. Using the Dynamic Light scattering [DLS] for the determination of the hydrodynamic size and surface zeta potential, a narrow sample size distribution was obtained of (18, 68, and 190 nm for charcoal, 105, 255, and 712 nm for doxorubicin, and 91, 295, and 955 nm for sorafenib), respectively. A surface charge of −13.2, −15.6 and −17 was obtained for charcoal, doxorubicin/charcoal, and sorafenib/charcoal nanoparticles. The cytotoxic activity of Doxorubicin-ACNP and Sorafenib-ACNP was evaluated in-vitro against HepG2 cell lines and it was observed that Drug loaded ACNP improved anticancer activity when compared to Doxorubicin or Sorafenib alone. Moreover, testing the toxicity potential of DOX-ACNP and Sorafenib-ACNP showed a significant reduction in the hemolysis of red blood cells when compared to Doxorubicin and Sorafenib alone. Conclusion: In conclusion, it is notable to state that this study is regarded as the first to investigate the use of Activated charcoal for the loading of Doxorubicin and Sorafenib for further use in the arena of hepatocellular carcinoma. Doxorubicin-ACNP and Sorafenib-ACNP showed noteworthy anticancer activity along with a reduced potential of RBCs hemolysis rendering it as an efficacious carrier with a low toxicity potential.

p53 Contributes to the Chemotherapeutic Drug Doxorubicin-Induced Cell Death in Colorectal Cancer Cell Line HCT116

Doxorubicin is a commonly used chemotherapy drug for cancer treatment,although its effectiveness varies across different cancer types.p53 is a key factor involved in cell death induced by therapeutic agents,and it can be upregulated by doxorubicin,exhibiting a function of apoptosis.To further investigate the mechanism between p53 and doxorubicin,this study explored whether p53 plays a role in doxorubicin-induced cell death in the colorectal cancer line HCT116.The findings revealed that p53 was upregulated in HCT116 cells when treated with doxorubicin,and the knockdown of p53 decreased the sensitivity of HCT116 cells to doxorubicin.These results suggest that p53 plays an important role in doxorubicin-induced cell death in HCT116 cells,potentially contributing to more effective treatment approaches.

Targeted hyperalkalization with NaOH-loaded starch implants enhances doxorubicin efficacy in tumor treatment

High-alkali treatment using sodium hydroxide(NaOH)injection can be a therapeutic approach for killing tumor cells.Alkalization can damage cellular structures and lead to cell death.Increased alkalinity can also enhance the efficacy of certain chemotherapeutic drugs such as doxorubicin(DOX).In this study,NaOH-loaded starch implants(NST implants)were used to induce hyperalkalization(increase pH)in the tumor environment,thereby inducing necrosis and enhancing the effects of DOX.NaOH is a strongly alkaline substance that can increase the pH when injected into a tumor.However,the administration of NaOH can have toxic side effects because it increases the pH of the entire body,not just at the tumor site.To overcome this problem,we developed an injectable NST implant,in which NaOH can be delivered directly into the tumor.This study showed that NST implants could be easily administered intratumorally in mice bearing 4T1 tumors and that most of the NaOH released from the NST implants was delivered to the tumors.Although some NaOH from NST implants can be systemically absorbed,it is neutralized by the body’s buffering effect,thereby reducing the risk of toxicity.This study also confirmed both in vitro and in vivo that DOX is more effective at killing 4T1 cells when alkalized.It has been shown that administration of DOX after injection of an NST implant can kill most tumors.Systemic absorption and side effects can be reduced using an NST implant to deliver NaOH to the tumor.In addition,alkalinization induced by NST implants not only exerts anticancer effects but can also enhance the effect of DOX in killing cancer cells.Therefore,the combination of NaOH-loaded starch implants and DOX treatment has the potential to be a novel therapy for tumors.

Microwave ablation combined with transarterial chemoembolization containing doxorubicin hydrochloride liposome for treating primary and metastatic liver cancers

Aims:To determine the safety and efficacy of microwave ablation(MWA)and transarterial chemoembolization(TACE)with doxorubicin hydrochloride liposome(DHL)in patients with primary liver cancer(PLC)and metastatic liver cancer(MLC).Materials and methods:The medical records of patients with primary or metastatic liver cancer who underwent MWA combined with TACE containing DHL from March 2019 to March 2022 were collected and analyzed.Treatment-related adverse events(AEs)were recorded.Local tumor response was evaluated according to the modified RECIST criteria.Local tumor progression-free survival(LTPFS)and overall survival(OS)were calculated using the Kaplan-Meier method.Results:Altogether,96 patients with liver cancer were included(PLC,n=45;MLC,n=51).Forty(41.7%)patients experienced AEs during treatment,and eight(8.3%)patients developed grade 3 AEs.Compared to before treatment,the serum total bilirubin level and neutrophil to lymphocyte ratio significantly increased after treatment.The median LTPFS was 14.5 months in patients with PLC and 10.7 months in patients with MLC.The median OS was not reached in patients with PLC or MLC.The 1-month and 3-month disease control rates reached more than 80%in both groups.Conclusion:MWA combined with TACE with DHL may be a safe and effective method for the treatment of liver cancer.

Research progress on cardiotoxicity mechanism of doxorubicin and prevention and treatment of traditional Chinese medicine

Doxorubicin is an anthracycline antibiotic.As a broad-spectrum antitumor drug,it is widely used in clinic.However,doxorubicin is dose-dependent and shows obvious cardiotoxicity,which limits its clinical application.At present,the mechanism of doxorubicin induced cardiotoxicity has not been fully clarified.Reducing cardiotoxicity and improving the scope of clinical application have become the focus of research in recent years.This paper reviews the mechanism of doxorubicin cardiotoxicity and the prevention and treatment of doxorubicin cardiotoxicity with traditional Chinese medicine,in order to provide reference for the combined application of doxorubicin.

Nonclinical Study of the Active Components of Doxorubicin Hydrochloride Liposome Injection in Vivo

Objectives: A non-clinical study was performed to establish a LC-MS/MS method to determine the in vivo active components of doxorubicin hydrochloride liposome injection in the plasma of Sprague-Dawley rats. Methods: Ten male SD rats were administered tail vein with a single dose of 10 mg/kg, and the concentrations of doxorubicin hydrochloride in plasma, heart, liver, spleen, lung, and kidney were determined by liquid chromatography-tandem mass spectrometry, and the pharmacokinetic parameters were calculated. Results: The final concentration of doxorubicin hydrochloride ranged from 500 ng/mL to 250,000 ng/mL, and the lower limit of quantification was 500 ng/mL;the main pharmacokinetic parameters: T1/2 was (19.282 ± 10.305) h, Cmax was (118514.828 ± 26155.134) ng/mL, AUC0-24 and AUC0-∞ were (1216659.205 ± 192706.268) ng/mL⋅h and (2082244.523 ± 860139.487) ng/mL⋅h, MRT0-24 and MRT0-∞ were (9.237 ± 0.423) h and (26.52 ± 14.015) h, respectively, and clearance (CL) was (0.005 ± 0.002) mL/h⋅ng. Conclusions: The method is simple, rapid, and sensitive, which can be used for the determination of doxorubicin hydrochloride concentration in the plasma of SD rats and pharmacokinetic non-clinical studies.

Doxorubicin Stealth Liposomes Prepared with PEG-Distearoyl Phosphatidylethanolamine and Distribution as well as Antitumor Activity in Mice

目的：研制出能够逃避体内网状内皮细胞的阿霉素隐形脂质体，并考察其在生物体内的分布以及比较阿霉素隐形脂质体与阿霉素普通脂质体的抗肿瘤活性。方法：将聚乙二醇－二硬脂酰磷脂酰乙醇胺（PEG－DSPE）同磷脂酰胆碱和胆固醇材料加在一起，用硫酸铵梯度法制备阿霉素隐形脂质体，同法制备阿霉素普通脂质体（但脂膜中不含PEG－DSPE）；通过尾静脉注射给药，比较隐形脂质体阿霉素、普通脂质体阿霉素和游离型阿霉素（盐酸阿霉素注射液）给药后在小鼠各主要脏器组织和血液中的分布情况；采用动物移植性肿瘤实验法，用H22小鼠肝癌细胞接种于小鼠右侧腋皮下形成实体瘤，考察阿霉素隐形脂质体和普通脂质体给药后对实体瘤的瘤重抑制率。结果：通过硫酸铵梯度法制备出了包封率高达95％的阿霉素隐形脂质体；同游离型阿霉素和普通脂质体阿霉素相比，隐形脂质体阿霉素在血液中浓度显著提高，循环时间显著延长，在心脏中分布的浓度显著降低；按5mg·kg^-1剂量治疗，第二天给药和第七天给药治疗方案，阿霉素隐形脂质体给药组的瘤重抑制率均显著高于普通脂质体给药组的瘤重抑制率；按10mg·kg^-1剂量治疗，隐形脂质体给药组的瘤重抑制率比普通脂质体给药组的瘤重抑制率稍高。结论：用普通脂质体给药相比，隐形脂质体阿霉素给药后延长了其在小鼠血液中的循环时间，说明经过PEG－DSPE修饰后的脂质体有逃避网状内皮细胞吞噬的功能（隐形），并且隐形脂质体阿霉素的抗肿瘤活性显著地提高。

Simultaneous determination of doxorubicin and its dipeptide prodrug in mice plasma by HPLC with fluorescence detection

A simple and sensitive high performance liquid chromatography with fluorescence detection （HPLC-FD） has been developed for simultaneous quantification of doxorubicin （DOX） and its dipeptide conjugate prodrug （PDOX） in mice plasma. The chromatographic separation was carried out on an Amethyst C18-H column with gradient mobile phase of 0.1% formic acid and 0.1% formic acid in acetonitrile at a flow rate of 1.0 mL/min. The excitation and emission wavelengths were set at 490 and 550 nm, respectively. The method was comprehensively validated. The limits of detection were low up to 5.0 ng/mL for DOX and 25.0 ng/mL for PDOX. And the limits of quantification were low up to 12.5 ng/mL for DOX and 50 ng/mL for PDOX, which were lower than those for most of the current methods. The calibration curves showed good linearity （R2 〉 0.999） over the concentration ranges. The extraction recoveries ranged from 84.0% to 88.2% for DOX and from 85.4% to 89.2% for PDOX. Satisfactory intra-day and inter-day precisions were achieved with RSDs less than 9.1%. The results show that the developed HPLC-FD method is accurate, reliable and will be helpful for preclinical pharmacokinetic study of DOX and PDOX.

Fabrication of an electrochemical sensor for determination of doxorubicin in human plasma and its interaction with DNA

In this work, an electrochemical sensor was fabricated for determination of an anthracycline, doxorubicin(DOX) as a chemotherapy drug in plasma based on multi-walled carbon nanotubes modified platinum electrode(Pt/MWCNTs). DOX was effectively accumulated on the surface of modified electrode and generated a pair of redox peaks at around 0.522 and 0.647 V(vs. Ag/Ag Cl) in Britton Robinson(B-R) buffer(p H 4.0, 0.1 M). The electrochemical parameters including p H, type of buffer, accumulation time, amount of modifier and scan rate were optimized. Under the optimized conditions, there was a linear correlation between cathodic peak current and concentration of DOX in the range of 0.05–4.0 μg/m L with the detection limit of 0.002 μg/m L. The number of electron transfers(n) and electron transfer-coefficient(α) were estimated as 2.0 and 0.25, respectively. The constructed sensor displayed excellent precision, sensitivity, repeatability and selectivity in the determination of DOX in plasma. Moreover, cyclic voltammetry studies of DOX in the presence of DNA showed an intercalation mechanism with binding constant(K_b) of 1.12×10~5L/mol.

Conventional treatments and non-PEGylated liposome encapsulated doxorubicin for visceral leishmaniasis:A scoping review

Visceral leishmaniasis(VL),also known as Kala-azar,is caused by Leishmania(L.)donovani complex,which includes L.donovani and L.infantum and is associated with a high death rate as compared to the cutaneous and subcutaneous form.Treatment of VL includes chemotherapeutic agents which are associated with some major hurdles like toxicities,parenteral administration,high cost,parasite resistance and stability.Hence,there is an urgent requirement to develop novel chemotherapeutic agents or repurposing of existing drugs against VL.Developing formulation of new chemical entity for the treatment of VL is laborious,time consuming and associated with huge financial burden.However,screening of existing chemotherapeutic agents is a good alternative to avail cost-effective treatment option for VL.Non-PEGylated liposome encapsulated doxorubicin(Myocet®)is proposed as an alternative treatment option for VL in this review article.Here,we covered the fundamental aspects of VL,loophole associated with available current treatment strategies and non-PEGylated liposome encapsulated doxorubicin as a novel alternative formulation for treating VL,as this liposomal delivery system of doxorubicin might passively target the intra-cellular regions of macrophage.

DL1106与doxorubicin和paclitaxel协同作用及其机制研究

目的探讨DL1106与doxorubicin和paclitaxel对三阴性乳腺癌细胞协同作用效果及研究机制。方法将三阴性乳腺癌细胞MDA-MB-231和BT549分为4组,对照组,DL1106,DL1106+doxorubicin,DL1106+paclitaxel组作用24和48 h。用流式细胞仪检测细胞凋亡率和细胞周期;用JC-1检测细胞膜电位;用Caspase-Glo?3/7 assay检测细胞内胱天蛋白酶活性;用Western blotting检测细胞周期、细胞凋亡相关蛋白表达。采用si RNA技术敲低P53和PUMA的表达后检测药物联合对细胞的作用效果。结果与DL1106单独作用组细胞相比,DL1106与doxorubicin和paclitaxel联合作用组的细胞在48 h后凋亡率显著下降。DL1106与doxorubicin和paclitaxel联合作用导致细胞膜电位大幅下降并使细胞内胱天蛋白酶活性显著升高。同对照组相比,DL1106,DL1106+doxorubicin,DL1106+paclitaxel作用组的细胞均抑制MDM2的表达,促进P53和PUMA的表达。DL1106+doxorubicin,DL1106+paclitaxel协同作用抑制细胞Cyclin D1和Bcl-2的表达,促进BAX的表达。用P53si RNA和PUMA si RNA分别敲低细胞P53和PUMA的表达后,发现DL1106+doxorubicin,DL1106+paclitaxel联合作用效果明显减弱。结论 DL1106与doxorubicin和paclitaxel对三阴性乳腺癌细胞均具有协同作用,且这种协同作用通过P53/PUMA/BAX/caspase途径发挥作用。

Neoadjuvant Combination Chemotherapy with Pegylated Liposomal Doxorubicin and Vinorelbine for Locally Advanced Breast Cancer

OBJECTIVE In China, vinorelbine plus an anthracycline is a common neoadjuvant regimen for locally-advanced breast cancer （LABC）. Pegylated liposomal doxorubicin （PLD） is an alternate anthracycline formulation with a more favorable safety profile compared with conventional anthracyclines. METHODS In this open-label trial, 61 women with LABC received up to 6 cycles of PLD 30 mg/m2 on Day 1 and vinorelbine 25 mg/m2 on Days 1 and 8 every 21 days. Hormone receptor and/or HER2 status was not routinely available. RESULTS The overall clinical response rate （primary efficacy endpoint） was 80% （95% CI： 68%-89%）. Two patients achieved a pathological complete response （3%）, with 75% having their tumor down-staged, and 89% proceeding to tumor resection. The most frequent nonhematologic adverse events were stomatitis, fever, rash, and palmar-plantar erythrodysesthesia, with none considered serious. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 10% and 2% of patients, respectively. CONCLUSION PLD plus vinorelbine demonstrated comparable efficacy to conventional anthracyclines plus vinorelbine in the neoadjuvant treatment of LABC, but may offer safety advantages.

Experimental study on antitumor effect of arsenic trioxide in combination with cisplatin or doxorubicin on hepatocellular carcinoma

INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo studies[1-5]. Due to limited effectiveness when any anti-carcinogen is used alone and obviously increased toxicity when the dose is raised, there is no exception for As2O3. Furthermore, combined chemotherapy contributes to improve therapeutic effectiveness, disperse toxicity and surmount drug-resistance,in which the combination of traditional Chinese and modern medicine has more advantages and characteristics. As a result,we made an experimental study on anti-tumor effect of As2O3in combination with cisplantin (PDD) or doxorubicin (ADM)on HCC. to investigate the possibility of AS2O3 in combination with PDD or ADM and nature of interaction between them,and to provide experimental basis for clinical application.

PEComa of the colon resistant to sirolimus but responsive to doxorubicin/ifosfamide

A 23-year-old male presented with a three-week-history of crampy abdominal pain and melaena.Colonoscopy revealed a friable mass filling the entire lumen of the cecum;histologically,it was classified as perivascular epithelioid cell tumor(PEComa).An magnetic resonance imaging scan showed,in addition to the primary tumor,two large mesenteric lymph node metastases and four metastatic lesions in the liver.The patient underwent right hemicolectomy and left hemihepatectomy combined with wedge resections of metastases in the right lobe of the liver,the resection status was R0.Subsequently,the patient was treated with sirolimus.After 4 mo of adjuvant mammalian target of rapamycin inhibition he developed two new liver metastases and a local pelvic recurrence.The visible tumor formations were again excised surgically,this time the resection status was R2 with regard to the pelvic recurrence.The patient was treated with 12 cycles of doxorubicin and ifosfamide under which the disease was stable for 9 mo.The clinical course was then determined by rapid tumor growth in the pelvic cavity.Second line chemotherapy with gemcitabine and docetaxel was ineffective,and the patient died 23 mo after the onset of disease.This case report adds evidence that,in malignant PEComa,the mainstay of treatment is curative surgery.If not achievable,the effects of adjuvant or palliative chemotherapy are unpredictable.

MiR-34a overexpression enhances the inhibitory effect of doxorubicin on HepG2 cells

BACKGROUND Hepatocellular carcinoma(HCC) is the third leading cause of death from malignant tumors worldwide. More than 50% of HCC cases occur in China. The prognosis remains poor and overall efficacy is still unsatisfactory. Chemotherapy resistance is the most important reason for the poor outcome. Much progress has been made in the study of chemotherapy resistance of HCC;however, the specific mechanisms of progression of HCC have still only been partially established.Therefore, the mechanism of chemotherapy resistance in HCC requires more research.AIM To investigate the effect of miR-34 a expression on the growth inhibition of HepG2 cells by doxorubicin.METHODS A recombinant lentiviral vector containing miR-34 a was constructed and transfected into HepG2 cells. The expression of miR-34 a was detected by reverse transcription-polymerase chain reaction(commonly known as RT-PCR) before and after transfection. Cells were exposed to 2 μM doxorubicin or phosphatebuffered saline before and after transfection. Cell viability in each group was detected by MTT assay, and cell cycle and apoptosis were detected by flow cytometry. Changes in expression levels of phospho(p)-p53, sirtuin(SIRT) 1,cyclin D1, cyclin-dependent kinase(CDK) 4, CDK6, BCL-2, multidrug resistance protein(MDR) 1/P glycoprotein(P-gp), and AXL were detected by Western blotting.RESULTS Recombinant lentiviral vector LV-hsa-mir-34 a was successfully constructed by restriction endonuclease digestion and sequencing. RT-PCR showed that expression of miR-34 a in HepG2 cells was significantly upregulated after transfection(P < 0.01). MTT assay showed that growth of HepG2 cells was inhibited after upregulation of miR-34 a, and viability was significantly decreased after combined treatment with doxorubicin(P < 0.01). Flow cytometry showed that the number of HepG2 cells in G1 phase increased, and G1 phase arrest was more obvious after intervention with doxorubicin(P < 0.01). The apoptosis rate of HepG2 cells was increased after upregulation of miR-34 a, and became more obvious after intervention with doxorubicin(P < 0.01). Western blotting showed that upregulation of miR-34 a combined with treatment with doxorubicin caused significant changes in the expression levels of p-p53, SIRT1, cyclin D1, CDK4,CDK6, BCL-2, MDR1/P-gp and AXL proteins(P < 0.01).CONCLUSION MiR-34 a may enhance the inhibitory effect of doxorubicin by downregulating MDR1/P-gp and AXL, which may be related to p53 expression.

Synergistic growth inhibitory effects of Phyllanthus emblica and Terminalia bellerica extracts with conventional cytotoxic agents:Doxorubicin and cisplatin against human hepatocellular carcinoma and lung cancer cells

AIM: To examine the growth inhibitory effects of Phyllanthus emblica (P. emblica) and Terminalia bellerica (T. bellerica) extracts on human hepatocellular carcinoma (HepG2), and lung carcinoma (A549) cells and their synergistic effect with doxorubicin or cisplatin. METHODS: HepG2 and A549 cells were treated with P. emblica and T. bellerica extracts either alone or in combination with doxorubicin or cisplatin and effects on cell growth were determined using the sulforhodamine B (SRB) assay. The isobologram and combination index (CI) method of Chou-Talalay were used to evaluate interactions between plant extracts and drugs. RESULTS: P. emblica and T. bellerica extracts demonstrated growth inhibitory activity, with a certain degree of selectivity against the two cancer cell lines tested. Synergistic effects (CI < 1) for P. emblica /doxorubicin or cisplatin at different dose levels were demonstrated in A549 and HepG2 cells. The T. bellerica/ cisplatin or doxorubicin also showed synergistic effects in A549 and HepG2 cells. In some instances, the combinations resulted in antagonistic effects. The dose reduction level was different and specific to each combination and cell line. CONCLUSION: The growth inhibitory activity of doxorubicin or cisplatin, as a single agent, may be modified by combinations of P. emblica or T. bellerica extracts and be synergistically enhanced in some cases. Depending on the combination ratio, the doses for each drug for a given degree of effect in the combination may be reduced. The mechanisms involved in this interaction between chemotherapeutic drugs and plant extracts remain unclear and should be further evaluated.

Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-related protein Bax,Bcl-2 and caspase-3 expressions were measured by immunohistochemical staining.RESULTS:Treatment with Melatonin(10 -8 -10 -5 mol/L) alone had a dose-related inhibitory effect on cell proliferation but no cytotoxic effect on hepatoma cell lines HepG2 and Bel-7402.Interestingly,when combined with Doxorubicin,Melatonin significantly increased the effects of cell growth inhibition and cell apoptosis.Furthermore,TUNEL staining and flow cytometry revealed that cooperative apoptosis induction was associated with decreased expression of Bcl-2 as well as increased expression of Bax and Caspase3.CONCLUSION:The synergism of Melatonin and Doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

Objective:To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells(MCF-7/Dox)in cytotoxicity apoptosis and P-glycoprotein(Pgp)expression in combination with doxorubicin.Methods:The cytotoxic properties.50%inhibition concentration(IC_(50))and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin(MCF-7/Dox)cells were determined using MTT assay.Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange.Immunocytochemistry assay was performed to determine the level and localization of Pgp.Results:Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC_(50)value of 11μmol/L.Thus,combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect(CI>1.0).Hesperidin did not increase the apoptotic induction,but decreased the Pgp expressions level when combined with doxorubicin in low concentration.Conclusions:Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC_(50)of 11μmol/L.Hesperidin did not increased the apoptotic induction combined with doxorubicin.Cochemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

Characterization and in vitro release studies of oral microbeads containing thiolated pectin–doxorubicin conjugates for colorectal cancer treatment

Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with cations such as Al3+, Ca2+ and Zn2+. The results showed that using zinc acetate can produce the strongest microbeads with spherical shape.However, the microbeads prepared from thiolated pectin–DOX conjugate were very soft and irregular in shape. To produce more spherical microbeads with suitable strength, the native pectin was then added to the formulations. The particle size of the microbeads ranged from 0.87 to 1.14 mm. The morphology of the microbeads was characterized by optical and scanning electron microscopy. DOX was still in crystalline form when used in preparing the microbeads, as confirmed by powder X-ray diffractometry. Drug release profiles showed that the microbeads containing thiolated pectin–DOX conjugate exhibited reduction-responsive character;in reducing environments, the thiolated pectin–DOX conjugate could uncouple resulting from a cleavage of the disulfide linkers and consequently release the DOX. The best-fit release kinetics of the microbeads containing thiolated pectin–DOX conjugate, in the medium without reducing agent, fit the Korsmeyer–Peppas model while those in the medium with reducing agent fit a zero-order release model. These results suggested that the microbeads containing thiolated pectin–DOX conjugate may be a promising platform for cancer-targeted delivery of DOX, exploiting the reducing environment typically found in tumors.