Beneficial effects of curcumin on antitumor activity and adverse reactions of doxorubicin

A comprehensive update on the potential of curcumin to enhance chemosensitivity in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers and a major cause of cancer-related mortality worldwide. The efficacy of chemotherapy agents in CRC treatment is often limited due to toxic side effects, heterogeneity of cancer cells, and the possibility of chemoresistance which promotes cancer cell survival through several mechanisms. Combining chemotherapy agents with natural compounds like curcumin, a polyphenol compound from the Curcuma longa plant, has been reported to overcome chemoresistance and increase the sensitivity of cancer cells to chemotherapeutics. Curcumin, alone or in combination with chemotherapy agents, has been demonstrated to prevent chemoresistance by modulating various signaling pathways, reducing the expression of drug resistance-related genes. The purpose of this article is to provide a comprehensive update on studies that have investigated the ability of curcumin to enhance the efficacy of chemotherapy agents used in CRC. It is hoped that it can serve as a template for future research on the efficacy of curcumin, or other natural compounds, combined with chemotherapy agents to maximize the effectiveness of therapy and reduce the side effects that occur in CRC or other cancers.

Investigation of green synchronous spectrofluorimetric approach for facile sensitive estimation of two co-administered anti-cancer drugs; curcumin and doxorubicin in their laboratory-prepared mixtures, human plasma, and urine

Recently, phytochemicals play an important role in cancer management. Curcumin (CUR), a natural phytochemical, has been co-administered with widespread chemotherapeutic agents such as doxorubicin (DOX) due to its excellent antitumor activity and the ability to lower the adverse reactions and drug resistance cells associated with DOX use. The present study aims to determine DOX and CUR utilizing a label-free, selective, sensitive, and precise synchronous spectrofluorimetric method. The obvious overlap between the emission spectra of DOX and CUR prevents simultaneous estimation of both analytes by conventional spectrofluorimetry. To solve such a problem, synchronous spectrofluorimetric measurements were recorded at Δλ = 20 nm, utilizing ethanol as a diluting solvent. Curcumin was recorded at 442.5 nm, whereas DOX was estimated at 571.5 nm, each at the zero-crossing point of the other one. The developed method exhibited linearity over a concentration range of 0.04-0.40 μg/mL for CUR and 0.05-0.50 μg/mL for DOX, respectively. The values of limit of detection (LOD) were 0.009 and 0.012 µg/mL, while the values of limit of quantitation (LOQ) were 0.028 and 0.037 µg/mL for CUR and DOX, respectively. The adopted approach was carefully validated according to the guidelines of ICH Q2R1. The method was utilized to estimate CUR and DOX in laboratory-prepared mixtures and human biological matrices. It showed a high percentage of recoveries with minimal RSD values. Additionally, three different tools were utilized to evaluate the greenness of the proposed approach.

Curcumin attenuates doxorubicin-induced cardiotoxicity via suppressing oxidative Stress, preventing inflammation and apoptosis: Ultrastructural and computational approaches

Currently, doxorubicin (DOX) is one of the medications commonly used in chemotherapy to treat different types of tumors.Nonetheless, despite being effective in multiple tumors, yet its use is limited owing to its cytotoxic effects, the therapeutic use of DOX has been limited. This work aimed to explore whether curcumin (CMN) can prevents DOX-induced cardiotoxicity in rats. Four groups of rats were created, with the first functioning as a control, while the second group received CMN. DOX alone was administered to the third group, whereas CMN and DOX were administered to the fourth group. Lipid peroxidation assessed as Malondialdehyde (MDA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), oxidative stress markers as catalase (CAT), superoxide dismutase (SOD), and inflammatory markers as tumor necrosis factor-alpha (TNF-α) in heart homogenates, each one was assessed. Heart specimens was investigated histologically and ultrastructurally. Increased, AST, and ALT serum levels, increased MDA levels, decreased SOD and CAT levels, and increased TNF-α concentrations in heart homogenates were all signs of DOX-induced myocardial injury. Histological and ultrastructural examinations revealed vacuoles and larger, swollen mitochondria in the cytoplasm. Furthermore, DOX caused significant changes in the myocardium, most notably nuclei disintegration, myofibrillar loss, and myocyte vacuolization. Using CMN with DOX reduced the harmful consequences of DOX on the myocardium by returning the increased AST and ALT levels to their original levels as compared to the control and reducing them. In cardiac tissue, CMN significantly increased the concentrations of SOD and CAT and significantly decreased the concentrations of MDA and TNF-α. Biochemical and histological studies have demonstrated that CMN has a heart-protective effect that might be related to its antioxidant and anti-inflammatory capabilities.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

A systematic review of the protective effects of silymarin/silibinin against doxorubicin-induced cardiotoxicity

PURPOSE

Although doxorubicin chemotherapy is commonly applied for treating different malignant tumors, cardiotoxicity induced by this chemotherapeutic agent restricts its clinical use. The use of silymarin/silibinin may mitigate the doxorubicin-induced cardiac adverse effects. For this aim, the potential cardioprotective effects of silymarin/silibinin against the doxorubicin-induced cardiotoxicity were systematically reviewed.

METHODS

In this study, we performed a systematic search in accordance with PRISMA guideline for identifying all relevant studies on "the role of silymarin/silibinin against doxorubicin-induced cardiotoxicity" in different electronic databases up to June 2022. Sixty-one articles were obtained and screened based on the predefined inclusion and exclusion criteria. Thirteen eligible papers were finally included in this review.

RESULTS

According to the echocardiographic and electrocardiographic findings, the doxorubicin-treated groups presented a significant reduction in ejection fraction, tissue Doppler peak mitral annulus systolic velocity, and fractional shortening as well as bradycardia, prolongation of QT and QRS interval. However, these echocardiographic abnormalities were obviously improved in the silymarin plus doxorubicin groups. As well, the doxorubicin administration led to induce histopathological and biochemical changes in the cardiac cells/tissue; in contrast, the silymarin/silibinin co-administration could mitigate these induced alterations (for most of the cases).

CONCLUSION

According to the findings, it was found that the co-administration of silymarin/silibinin alleviates the doxorubicin-induced cardiac adverse effects. Silymarin/silibinin exerts its cardioprotective effects via antioxidant, anti-inflammatory, anti-apoptotic activities, and other mechanisms.

The anticancer effect of PASylated calreticulin-targeting L-ASNase in solid tumor bearing mice with immunogenic cell death-inducing chemotherapy

L-Asparaginase (L-ASNase), a bacterial enzyme that degrades asparagine, has been commonly used in combination with several chemical drugs to treat malignant hematopoietic cancers such as acute lymphoblastic leukemia (ALL). In contrast, the enzyme was known to inhibit the growth of solid tumor cells in vitro, but not to be effective in vivo. We previously reported that two novel monobodies (CRT3 and CRT4) bound specifically with calreticulin (CRT) exposed on tumor cells and tissues during immunogenic cell death (ICD). Here, we engineered L-ASNases conjugated with monobodies at the N-termini and PAS200 tags at the C-termini (CRT3LP and CRT4LP). These proteins were expected to possess four monobody and PAS200 tag moieties, which did not disrupt the L-ASNase conformation. These proteins were expressed 3.8-fold more highly in E. coli than those without PASylation. The purified proteins were highly soluble, with much greater apparent molecular weights than expected ones. Their affinity (Kd) against CRT was about 2 nM, 4-fold higher than that of monobodies. Their enzyme activity (∼6.5 IU/nmol) was similar to that of L-ASNase (∼7.2 IU/nmol), and their thermal stability was significantly increased at 55 °C. Their half-life times were > 9 h in mouse sera, about 5-fold longer than that of L-ASNase (∼1.8 h). Moreover, CRT3LP and CRT4LP bound specifically with CRT exposed on tumor cells in vitro, and additively suppressed the tumor growth in CT-26 and MC-38 tumor-bearing mice treated with ICD-inducing drugs (doxorubicin and mitoxantrone) but not with a non-ICD-inducing drug (gemcitabine). All data indicated that PASylated CRT-targeted L-ASNases enhanced the anticancer efficacy of ICD-inducing chemotherapy. Taken together, L-ASNase would be a potential anticancer drug for treating solid tumors.

Nanoparticle-Based Therapeutics to Overcome Obstacles in the Tumor Microenvironment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is still a main health concern around the world, with a rising incidence and high mortality rate. The tumor-promoting components of the tumor microenvironment (TME) play a vital role in the development and metastasis of HCC. TME-targeted therapies have recently drawn increasing interest in the treatment of HCC. However, the short medication retention time in TME limits the efficiency of TME modulating strategies. The nanoparticles can be elaborately designed as needed to specifically target the tumor-promoting components in TME. In this regard, the use of nanomedicine to modulate TME components by delivering drugs with protection and prolonged circulation time in a spatiotemporal manner has shown promising potential. In this review, we briefly introduce the obstacles of TME and highlight the updated information on nanoparticles that modulate these obstacles. Furthermore, the present challenges and future prospects of TME modulating nanomedicines will be briefly discussed.

A systematic review of nonclinical studies on the effect of curcumin in chemotherapy-induced cardiotoxicity

BACKGROUND

Various anticancer drugs are effective therapeutic agents for cancer treatment; however, they cause severe toxicity in body organs. Cardiotoxicity is one of the most critical side effects of these drugs. Based on various findings, turmeric extract has positive effects on cardiac cells.

OBJECTIVE

This study aims to evaluate how curcumin as the main component of turmeric may affect chemotherapy-induced cardiotoxicity.

METHOD

Database search was performed up to April 2021 using "curcumin OR turmeric OR Curcuma longa" and "chemotherapy-induced cardiac disease," including all their equivalents and similar terms. After screening the total articles obtained from the electronic databases, 25 relevant articles were included in this systematic review.

RESULTS

The studies demonstrate lower body weight and increased mortality rates due to doxorubicin administration. Besides, cancer therapeutic agents induced various morphological and biochemical abnormalities compared to the non-treated groups. Based on most of the obtained results, curcumin at nontoxic doses can protect the cardiac cells mainly through modulating antioxidant capacity, regulation of cell death, and anti-inflammatory effects. Nevertheless, according to a minority of findings, curcumin increases the susceptibility of the rat cardiomyoblast cell line (H9C2) to apoptosis triggered by doxorubicin.

CONCLUSION

According to most nonclinical studies, curcumin can have the potential of cardioprotective effects against cardiotoxicity induced by chemotherapy. However, based on limited, contradictory findings demonstrating the function of curcumin in potentiating doxorubicin-induced cardiotoxicity, well-designed studies are needed to evaluate the safety and effectiveness of treatment with new formulations of this compound during cancer therapy.

The cardioprotective effects of nano-curcumin against doxorubicin-induced cardiotoxicity: A systematic review

Although the chemotherapeutic drug, doxorubicin, is commonly used to treat various malignant tumors, its clinical use is restricted because of its toxicity especially cardiotoxicity. The use of curcumin may alleviate some of the doxorubicin-induced cardiotoxic effects. Especially, using the nano-formulation of curcumin can overcome the poor bioavailability of curcumin and enhance its physicochemical properties regarding its efficacy. In this study, we systematically reviewed the potential cardioprotective effects of nano-curcumin against the doxorubicin-induced cardiotoxicity. A systematic search was accomplished based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the identification of all relevant articles on "the role of nano-curcumin on doxorubicin-induced cardiotoxicity" in the electronic databases of Scopus, PubMed, and Web of Science up to July 2021. One hundred and sixty-nine articles were screened following a predefined set of inclusion and exclusion criteria. Ten eligible scientific papers were finally included in the present systematic review. The administration of doxorubicin reduced the body and heart weights of mice/rats compared to the control groups. In contrast, the combined treatment of doxorubicin and nano-curcumin increased the body and heart weights of animals compared with the doxorubicin-treated groups alone. Furthermore, doxorubicin could significantly induce the biochemical and histological changes in the cardiac tissue; however, coadministration of nano-curcumin formulation demonstrated a pattern opposite to the doxorubicin-induced changes. The coadministration of nano-curcumin alleviates the doxorubicin-induced cardiotoxicity through various mechanisms including antioxidant, anti-inflammatory, and antiapoptotic effects. Also, the cardioprotective effect of nano-curcumin formulation against doxorubicin-induced cardiotoxicity was higher than free curcumin.

In Vitro and In Vivo Cardioprotective Effects of Curcumin against Doxorubicin-Induced Cardiotoxicity: A Systematic Review

Objective

This study aimed to review the potential chemoprotective effects of curcumin against the doxorubicin-induced cardiotoxicity.

Methods

According to the PRISMA guideline, a comprehensive systematic search was performed in different electronic databases (Web of Science, PubMed, and Scopus) up to July 2021. One hundred and sixty-four studies were screened in accordance with a predefined set of inclusion and exclusion criteria. Eighteen eligible articles were finally included in the current systematic review.

Results

According to the in vitro and in vivo findings, it was found that doxorubicin administration leads to decreased cell survival, increased mortality, decreased bodyweight, heart weight, and heart to the bodyweight ratio compared to the control groups. However, curcumin cotreatment demonstrated an opposite pattern in comparison with the doxorubicin-treated groups alone. Other findings showed that doxorubicin significantly induces biochemical changes in the cardiac cells/tissue. Furthermore, the histological changes on the cardiac tissue were observed following doxorubicin treatment. Nevertheless, for most of the cases, these biochemical and histological changes mediated by doxorubicin were reversed near to control groups following curcumin coadministration.

Conclusion

It can be mentioned that coadministration of curcumin alleviates the doxorubicin-induced cardiotoxicity. Curcumin exerts these cardioprotective effects through different mechanisms of antioxidant, antiapoptosis, and anti-inflammatory. Since the finding presented in this systematic review are based on in vitro and in vivo studies, suggesting the use of curcumin in cancer patients as a cardioprotector agent against cardiotoxicity mediated by doxorubicin requires further clinical studies.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

Gut microbiota enhances the chemosensitivity of hepatocellular carcinoma to 5-fluorouracil in vivo by increasing curcumin bioavailability

5-Fluorouracil (5-Fu) is efficient for hepatocellular carcinoma (HCC) treatment, but fast-emerging resistance limits its usage. Curcumin is being investigated for its potential chemosensitivity, but its low oral bioavailability hinders its chemosensitivity effect in vivo. Gut microbiota modulation is considered to contribute to its bioactivities in vivo. In the current study, we demonstrate that curcumin can enhance 5-Fu chemosensitivity in HCC cells in vitro, increase the apoptosis rate, arrest the cell cycle at G2/M phase, and block the PI3k/AKT/mTOR signalling pathway by inhibiting the phosphorylation of PI3K and its downstream protein kinases. Curcumin also remarkably sensitized H22 cells to 5-Fu, allowing it to inhibit tumour growth in vivo. 16S rDNA sequencing suggests that curcumin in combination with 5-Fu significantly alters the gut microbiota composition based on alpha and beta diversity analysis compared to drug treatment alone. Gut microbiota depletion abolished curcumin's chemosensitivity effect in vivo. A pharmacodynamics study suggested that the gut microbiota increased the oral bioavailability of curcumin (AUC_(0-t) 15.24 ± 0.77 μM/h [wt] vs. 3.04 ± 0.18 μM/h [gut microbiota depleted]). In conclusion, curcumin can increase the chemosensitivity of HCC to 5-Fu in vitro and in vivo, and gut microbiota plays a key role in its effect in vivo.

Synergistic breast cancer suppression efficacy of doxorubicin by combination with glycyrrhetinic acid as an angiogenesis inhibitor

BACKGROUND

Therapeutic regimens of breast cancer treatment are increasingly inclined to adopt combination strategy based on the broad spectrum antitumor effect of doxorubicin (Dox). Currently, combination therapy comprises of conventional anti-cancer drugs and angiogenesis inhibitors have been corroborated as an effective approach in cancer treatment.

PURPOSE

We explored the ability of a natural anti-angiogenic compound glycyrrhetinic acid (GA), derived from an edible-medicinal herb licorice, to enhance the breast cancer suppression effect of Dox.

STUDY DESIGN

The drug ratio of GA and Dox with synergistic anticancer effect against MCF-7 cells was optimized by combination index (CI) value in vitro, followed by evaluation of the improved anticancer effects and reduced side-effects of this combination in vitro and in vivo.

METHODS

Cell viability was measured by MTT assay. Analyses of mitochondrial membrane potential and cell apoptosis on MCF-7 cells were performed by JC-1 dye and Annexin V-FITC/PI assays. The cellular accumulation of Dox when combined with GA was evaluated. Levels of apoptosis-related proteins in MCF-7 cells were measured by Western blot analysis. Synergistic anti-angiogenic effects on HUVECs were evaluated. A breast cancer mouse model was established to investigate the anti-tumor effects in vivo.

RESULTS

Based on the optimization by CI value, Dox and GA at 1:20 molar ratio was chosen as the optimal combination drug ratio that exhibited synergistic effect against MCF-7 breast cancer cells. In addition, the combination of GA and Dox exhibited significantly enhanced cytotoxicity, apoptosis, and loss of mitochondrial membrane potential via the upregulation of a mitochondrial-dependent apoptosis pathway against MCF-7 cells. Interestingly, the addition of GA increased the intracellular accumulation of Dox in MCF-7 cells. Moreover, VEGF-induced HUVECs proliferation, migration, and tube formation were strongly inhibited by Dox when used with GA via the significant down-regulation of VEGFR2-mediated pathway, indicating that the combination of Dox and GA could exhibit ideal synergistic anti-angiogenesis effect. Expectedly, the enhanced anti-tumor efficacy of Dox and reduced Dox-induced cardiotoxicity when used in combination with GA were evident in a mouse breast tumor model.

CONCLUSIONS

These findings support that the combination of Dox with GA is a novel and promising therapeutic strategy for the treatment of breast cancer.

Comparison of the protective effects of curcumin and caffeic acid phenethyl ester against doxorubicin-induced testicular toxicity

Whether testicular toxicity is mediated by matrix metalloproteinases (MMPs) is an important question that has not been examined. This study investigated the suppressive effect of curcumin and caffeic acid phenethyl ester (CAPE) on oxidative stress, apoptosis, and whether MMPs mediate doxorubicin (DOX)-induced testicular injury. Male rats were randomly divided into eight groups (n = 8 per group). The groups were as follows: sham, dimethyl sulphoxide (100 µL), DOX (3 mg/kg), CAPE (2.68 mg/kg), curcumin (30 mg/kg), DOX+CAPE (3 mg/kg DOX and 2.68 mg/kg CAPE), DOX+curcumin (3 mg/kg DOX and 30 mg/kg curcumin) and DOX+CAPE+curcumin (3 mg/kg DOX, 2.68 mg/kg CAPE and 30 mg/kg curcumin). Injections were administered daily for 21 days. The oxidative stress, MMPs, proinflammatory cytokines and apoptotic markers in the DOX group were higher than the sham group (p < .05); these measures were lower in the groups treated with CAPE and curcumin together with DOX compared with the DOX group (p < .05). The results showed that MMPs mediated DOX-induced testicular injury, but CAPE and especially curcumin suppressed testis injury and cell apoptosis by suppressing DOX-induced increases in MMPs, oxidative stress and proinflammatory cytokines. However, curcumin exhibited more pronounced effects than CAPE in terms of all studied parameters.

Polychemotherapy with Curcumin and Doxorubicin via Biological Nanoplatforms: Enhancing Antitumor Activity

Doxorubicin (DOX) is a well-known chemotherapeutic agent extensively applied in the field of cancer therapy. However, similar to other chemotherapeutic agents such as cisplatin, paclitaxel, docetaxel, etoposide and oxaliplatin, cancer cells are able to obtain chemoresistance that limits DOX efficacy. In respect to dose-dependent side effect of DOX, enhancing its dosage is not recommended for effective cancer chemotherapy. Therefore, different strategies have been considered for reversing DOX resistance and diminishing its side effects. Phytochemical are potential candidates in this case due to their great pharmacological activities. Curcumin is a potential antitumor phytochemical isolated from Curcuma longa with capacity of suppressing cancer metastasis and proliferation and affecting molecular pathways. Experiments have demonstrated the potential of curcumin for inhibiting chemoresistance by downregulating oncogene pathways such as MMP-2, TGF-β, EMT, PI3K/Akt, NF-κB and AP-1. Furthermore, coadministration of curcumin and DOX potentiates apoptosis induction in cancer cells. In light of this, nanoplatforms have been employed for codelivery of curcumin and DOX. This results in promoting the bioavailability and internalization of the aforementioned active compounds in cancer cells and, consequently, enhancing their antitumor activity. Noteworthy, curcumin has been applied for reducing adverse effects of DOX on normal cells and tissues via reducing inflammation, oxidative stress and apoptosis. The current review highlights the anticancer mechanism, side effects and codelivery of curcumin and DOX via nanovehicles.

Vanillin Prevents Doxorubicin-Induced Apoptosis and Oxidative Stress in Rat H9c2 Cardiomyocytes

Doxorubicin (doxo) is an effective anticancer compound in several tumor types. However, as a consequence of oxidative stress induction and ROS overproduction, its high cardiotoxicity demands urgent attention. Vanillin possesses antioxidant, antiproliferative, antidepressant and anti-glycating properties. Therefore, we investigated the potential vanillin protective effects against doxo-induced cardiotoxicity in H9c2 cells. Using multiparametric approach, we demonstrated that vanillin restored both cell viability and damage in response to doxo exposure. Contextually, vanillin decreased sub-G1 appearance and caspase-3 and PARP1 activation, reducing the doxo-related apoptosis induction. From a mechanistic point of view, vanillin hindered doxo-induced ROS accumulation and impaired the ERK phosphorylation. Notably, besides the cardioprotective effects, vanillin did not counteract the doxo effectiveness in osteosarcoma cells. Taken together, our results suggest that vanillin ameliorates doxo-induced toxicity in H9c2 cells, opening new avenues for developing alternative therapeutic approaches to prevent the anthracycline-related cardiotoxicity and to improve the long-term outcome of antineoplastic treatment.

Improved pharmacokinetics and reduced side effects of doxorubicin therapy by liposomal co-encapsulation with curcumin

The goal of the current study was to investigate the pharmacokinetic profile, tissue distribution and adverse effects of long-circulating liposomes (LCL) with curcumin (CURC) and doxorubicin (DOX), in order to provide further evidence for previously demonstrated enhanced antitumor efficacy in colon cancer models. The pharmacokinetic studies were carried out in healthy rats, following the i.v. injection of a single dose of LCL-CURC-DOX (1 mg/kg DOX). For the tissue distribution study, DOX concentration in tumours, heart and liver were measured after the administration of two i.v. doses of LCL-CURC-DOX (2.5 mg/kg DOX and 5 mg/kg CURC) to Balb/c mice bearing C26 colon tumours. Markers of murine cardiac and hepatic oxidative status were determined to provide additional insights into the benefit of co-encapsulating CURC and DOX in LCL over DOX-induced adverse effects in these organs. The current study demonstrated that the liposomal association of CURC and DOX effectively improved the pharmacokinetics and biodistribution of DOX, limiting its side effects, via CURC-dependent antioxidant effects.

Combinations of the antioxidants sulforaphane or curcumin and the conventional antineoplastics cisplatin or doxorubicin as prospects for anticancer chemotherapy

Drugs used in clinical oncology have narrow therapeutic indices with adverse toxicity often involving oxidative damage. Chemoresistance to these conventional antineoplastics is usually mediated by oxidative stress-upregulated pathways such as those of nuclear factor-kappa B (NF-κB) and hypoxia-inducible factor-1 alpha (HIF-1α). Accordingly, the use of antioxidants in combinational approaches has begun to be considered for fighting cancer because of both the protective role against adverse effects and the ability to sensitize chemoresistant cancer cells. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been identified as a mediator of the cytoprotection but it is not regularly associated with tumor chemosensitization. However, some Nrf2 inducers could be exerting cytoprotective and chemosensitizing roles through a simple integrated mechanism in which the cellular level of reactive oxygen species is controlled, thus inhibiting the oxidative damage in non-target tissues and the tumor chemoresistance mediated by NF-κB or HIF-1α. As examples to show the general idea of this antioxidant combination chemotherapy, this review explores the preclinical information available for four combinations, each composed by a paradigmatic oncological drug (cisplatin or doxorubicin) and a recognized antioxidant (sulforaphane or curcumin). The issues for translating these outcomes to clinical trials are briefly discussed.

Delivery of natural phenolic compounds for the potential treatment of lung cancer

The application of natural products to treat various diseases, such as cancer, has been an important area of research for many years. Several phytochemicals have demonstrated anticarcinogenic activity to prevent or reduce the progression of cancer by modulating various cellular mechanisms. However, poor bioavailability has hindered clinical success and the incorporation of these drugs into efficient drug delivery systems would be beneficial. For lung cancer, local delivery via the pulmonary route would also be more effective. In this article, recent in vitro scientific literature on phenolic compounds with anticancer activity towards lung cancer cell lines is reviewed and nanoparticulate delivery is mentioned as a possible solution to the problem of bioavailability. The first part of the review will explore the different classes of natural phenolic compounds and discuss recent reports on their activity on lung cancer cells. Then, the problem of the poor bioavailability of phenolic compounds will be explored, followed by a summary of recent advances in improving the efficacy of these phenolic compounds using nanoparticulate drug delivery systems. Graphical abstract The rationale for direct delivery of phenolic compounds loaded in microparticles to the lungs.

Dual-loaded, long-term sustained drug releasing and thixotropic hydrogel for localized chemotherapy of cancer

A thixotropic injectable regenerated silk fibroin/hydroxypropylcellulose (RSF/HPC) hydrogel for highly sustainable dual-drug release with improved anticancer therapy and alleviated side effects.

Concurrent administration of anticancer chemotherapy drug and herbal medicine on the perspective of pharmacokinetics

With an increasing number of cancer patients seeking an improved quality of life, complementary and alternative therapies are becoming more common ways to achieve such improvements. The potential risks of concurrent administration are serious and must be addressed. However, comprehensive evidence for the risks and benefits of combining anticancer drugs with traditional herbs is rare. Pharmacokinetic investigations are an efficient way to understand the influence of concomitant remedies. Therefore, this study aimed to collect the results of pharmacokinetic studies relating to the concurrent use of cancer chemotherapy and complementary and alternative therapies. According to the National Health Insurance (NHI) database in Taiwan and several publications, the three most commonly prescribed formulations for cancer patients are Xiang-Sha-Liu-Jun-Zi-Tang, Jia-Wei-Xiao-Yao-San and Bu-Zhong-Yi-Qi-Tang. The three most commonly prescribed single herbs for cancer patients are Hedyotis diffusa, Scutellaria barbata, and Astragalus membranaceus. Few studies have discussed herb-drug interactions involving these herbs from a pharmacokinetics perspective. Here, we reviewed Jia-Wei-Xiao-Yao-San, Long-Dan-Xie-Gan-Tang, Curcuma longa and milk thistle to provide information based on pharmacokinetic evidence for healthcare professionals to use in educating patients about the risks of the concomitant use of various remedies.

Protective effects of curcumin against doxorubicin-induced toxicity and resistance: A review

Doxorubicin (DOX)-induced toxicity and resistance are major obstacles in chemotherapeutic approaches. Despite effective in the treatment of numerous malignancies, some clinicians have voiced concern that DOX has the potential to cause debilitating consequences in organ tissues, especially the heart. The mechanisms of toxicity and resistance are respectively related to induction of reactive oxygen species (ROS) and up-regulation of ATP-binding cassette (ABC) transporter. Curcumin (CUR) with several biological and pharmacological properties is expected to restore DOX-mediated impairments to tissues. This review is intended to address the current knowledge on DOX adverse effects and CUR protective actions in the heart, kidneys, liver, brain, and reproductive organs. Coadministration of CUR and DOX is capable of ameliorating DOX toxicity pertained to antioxidant, apoptosis, autophagy, and mitochondrial permeability.

Anticancer potential of novel curcumin analogs towards castrate-resistant prostate cancer

Prostate cancer is initially sensitive to hormone therapy; however, over time the majority of patients progress to a hormone-insensitive form classified as castration-resistant prostate cancer (CRPC). CRPC is highly metastatic and patients have a poor prognosis. Thus, new drugs for the treatment of this disease are required. In this study, we therefore examined the cytotoxic effects and anticancer mechanism(s) of action of second generation curcumin analogs towards CRPC cells. For this purpose, PC3 and DU145 cells were treated with a series of curcumin analogs at 0-10 µM for 72 h and cytotoxicity was determined by the sulforhodamine B (SRB) assay. Two compounds, 1-isopropyl-3,5-bis(pyridin-3-ylmethylene)-4-piperidone (RL118) and 1-methyl-3,5-[(6-methoxynaphthalen-2-yl)methylene]-4-piperidone (RL121), were found to have the most potent cytotoxic effect with EC50 values of 0.50 and 0.58 µM in the PC3 cells and EC50 values of 0.76 and 0.69 µM in the DU145 cells, respectively. Thus, further experiments were performed focusing on these two compounds. Flow cytometry was performed to determine their effects on the cell cycle and apoptosis. Both analogs increased the number of cells in the G2/M phase of the cell cycle and induced apoptosis. Specifically, in the PC3 cells, RL121 increased the number of cells in the G2/M phase by 86% compared to the control, while RL118 increased the number of cells in the G2/M phase by 42% compared to the control after 24 h. Moreover, both RL118 and RL121 induced the apoptosis of both cell lines. In the DU145 cells, a 38-fold increase in the number of apoptotic cells was elicited by RL118 and a 78-fold increase by RL121 compared to the control. Furthermore, the effects of both analogs on the expression of key proteins involved in cell proliferation were also determined by western blot analysis. The results revealed that both analogs inhibited the expression of nuclear factor (NF)-κB (p65/RelA), eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), p-4E-BP1, mammalian target of rapamycin (mTOR), p-mTOR, AKT and p-AKT. Thus, the findings of this study provide evidence that RL118 and RL121 have potent anticancer activity against CPRC cells, and both analogs warrant further investigation in vivo.

pH-sensitive polymeric nanoparticles for co-delivery of doxorubicin and curcumin to treat cancer via enhanced pro-apoptotic and anti-angiogenic activities

Co-delivery of multiple drugs with complementary anticancer mechanisms by nano-carriers offers an effective strategy to treat cancer. The combination of drugs with pro-apoptotic and anti-angiogenic activities is potentially effective in treating human hepatocellular carcinoma (HCC). Herein, we developed a co-delivery system for doxorubicin (Dox), a pro-apoptotic drug, and curcumin (Cur), a potent drug for antiangiogenesis, in pH-sensitive nanoparticles (NPs) constituted with amphiphilic poly(β-amino ester) copolymer. Dox & Cur co-loaded NPs ((D+C)/NPs) were prepared with optimized drug ratio, showing low polydispersity, high encapsulation efficiency, and enhanced release in the acidic environment of cancer cells. Furthermore, enhanced cellular internalization of cargoes delivered from (D+C)/NPs were observed in human liver cancer SMMC 7721 cells and human umbilical vein endothelial cells (HUVECs) compared to the use of free drugs. The (D+C)/NPs induced a high rate of apoptosis in SMMC 7721 cells through decreased mitochondrial membrane potential. Additionally, (D+C)/NPs exhibited stronger anti-angiogenic effects including inhibition of HUVEC proliferation, migration, invasion, and tube formation mediated VEGF pathway modulation in vitro and in vivo. Taken together, encapsulation of the pro-apoptotic drug Dox and antiangiogenic agent Cur in pH-sensitive NPs provides a promising strategy to effectively inhibit HCC progression in a synergistic manner.

STATEMENT OF SIGNIFICANCE

The combination of multiple drugs has been demonstrated to be more effective than single treatment. However, the different physicochemical and pharmacokinetic profiles of each drug render optimal delivery challenging. In view of the great delivery advantage of nanocarriers to unify the multiple drugs in vivo, stimulus-responsive nano-carriers are more crucial to increase efficacy and reduce toxicity from off-target exposure. Therefore, herein the pH-sensitive nanoparticles, composed by d-α-tocopheryl polyethylene glycol 1000-block-poly (β-amino ester) (TPGS-PAE) polymers, have been fabricated for doxorubicin (Dox) and curcumin (Cur) co-delivery, which exhibited diverse anticancer approaches, i.e. pro-apoptosis and antiangiogenesis. The precise intracellular target site and effective drug combination concentration result in the enhanced antitumor efficiency and the reduced systematic toxicity of Dox. The co-encapsulation of the pro-apoptotic drug and antiangiogenic agent in pH-sensitive NPs provides a promising strategy to effectively inhibit malignant neoplasm progression in a synergistic manner.

Development of antiproliferative long-circulating liposomes co-encapsulating doxorubicin and curcumin, through the use of a quality-by-design approach

The aim of this work was to use the quality-by-design (QbD) approach in the development of long-circulating liposomes co-loaded with curcumin (CUR) and doxorubicin (DOX) and to evaluate the cytotoxic potential of these liposomes in vitro using C26 murine colon carcinoma cell line. Based on a risk assessment, six parameters, namely the phospholipid, CUR and DOX concentrations, the phospholipid:cholesterol molar ratio, the temperature during the evaporation and hydration steps and the pH of the phosphate buffer, were identified as potential risk factors for the quality of the final product. The influence of these variables on the critical quality attributes of the co-loaded liposomal CUR and DOX was investigated: particle size, zeta potential, drug loading and entrapment efficiency. For this, a 2⁶⁻² factorial design was employed to establish a proper regression model and to generate the contour plots for the responses. The obtained data served to establish the design space for which different combinations of variables yielded liposomes with characteristics within predefined specifications. The validation of the model was carried out by preparing two liposomal formulations corresponding to the robust set point from within the design space and one outside the design space and calculating the percentage bias between the predicted and actual experimental results. The in vitro antiproliferative test showed that at higher CUR concentrations, the liposomes co-encapsulating CUR and DOX had a greater cytotoxic effect than DOX-loaded liposomes. Overall, this study showed that QbD is a useful instrument for controlling and optimizing the manufacturing process of liposomes co-loaded with CUR and DOX and that this nanoparticulate system possesses a great potential for use in colon cancer therapy.

One-step formation of lipid-polyacrylic acid-calcium carbonate nanoparticles for co-delivery of doxorubicin and curcumin

A doxorubicin (Dox) and curcumin (Cur) combination treatment regimen has been widely studied in pre-clinical research. However, the nanoparticles developed for this combination therapy require a consecutive drug loading process because of the different water-solubility of these drugs. This study provides a strategy for the "one-step" formation of nanoparticles encapsulating both Dox and Cur. We took advantage of polyacrylic acid (PAA) and calcium carbonate (CaCO₃) to realise a high drug entrapment efficiency (EE) and pH-sensitive drug release using a simplified preparation method. Optimisation of lipid ratios and concentrations of CaCO₃ was conducted. Under optimal conditions, the mean diameter of PEGylated lipid/PAA/CaCO₃ nanoparticles with encapsulated Cur and Dox (LPCCD) was less than 100 nm. An obvious pH-sensitive release of both drugs was observed, with different Dox and Cur release rates. Successful co-delivery of Cur and Dox was achieved via LPCCD on HepG2 cells. LPCCD altered the bio-distribution of Dox and Cur in vivo and decreased Dox-induced cardiotoxicity. The current investigation has developed an efficient ternary system for co-delivery of Dox and Cur to tumours, using a "one-step" formation resulting in nanoparticles possessing remarkable pH-sensitive drug release behaviour, which may be valuable for further clinical studies and eventual clinical application.

Using gene expression database to uncover biology functions of 1,4-disubstituted 1,2,3-triazole analogues synthesized via a copper (I)-catalyzed reaction

We have synthesized bioactive 1,4-disubstituted 1,2,3-triazole analogues containing 2H-1,4-benzoxazin-3-(4H)-one derivatives via 1,3-dipolar cycloaddition in the presence of CuI. All the reactions proceeded smoothly and afforded its desired products in excellent yields. Among these analogues, 3y exhibited a better cytotoxic effect on human hepatocellular carcinoma (HCC) Hep 3B cells and displayed less cytotoxicity on normal human umbilical vein endothelial cells, compared with Sorafenib, a targeted therapy for advanced HCC. 3y also induced stronger apoptosis and autophagy. Addition of curcumin enhanced 3y-induced cytotoxicity by further induction of autophagy. Using gene expression signatures of 3y to query Connectivity Map, a glycogen synthase kinase-3 inhibitor (AR-A014418) was predicted to display similar molecular action of 3y. Experiments further demonstrate that AR-A014418 acted like 3y, and vice versa. Overall, our data suggest the chemotherapeutic potential of 3y on HCC.

Anti-Cancer Phytometabolites Targeting Cancer Stem Cells

Medicinal plants are a plentiful source of bioactive molecules with much structural diversity. In cancer treatment, molecules obtained from plants represent an attractive alternative to other treatments because several plant-derived compounds have exhibited lower toxicity and higher selectivity against cancer cells. In this review, we focus on the possible application of bioactive molecules obtained from plants against more primitive cell populations in cancers, cancer stem cells. Cancer stem cells are present in several kinds of tumors and are responsible for recurrences and metastases. Common anti-cancer drugs exhibit lower effectiveness against cancer stem cells because of their biological features. However, recently discovered natural phytometabolites exert cytotoxic effects on this rare population of cells in cancers. Therefore, this review presents the latest research on promising compounds from plants that can act as antitumor drugs and that mainly affect stem cell populations in cancers.

Curcumin and Viscum album Extract Decrease Proliferation and Cell Viability of Soft-Tissue Sarcoma Cells: An In Vitro Analysis of Eight Cell Lines Using Real-Time Monitoring and Colorimetric Assays

BACKGROUND

The cytostatic effects of the polyphenol curcumin and Viscum album extract (VAE) were assessed in soft-tissue sarcoma (STS) cells.

METHODS

Eight human STS cell lines were used: fibrosarcoma (HT1080), liposarcoma (SW872, T778, MLS-402), synovial sarcoma (SW982, SYO1, 1273), and malignant fibrous histiocytoma (U2197). Primary human fibroblasts served as control cells. Cell proliferation, viability, and cell index (CI) were analyzed by BrdU assay, MTT assay, and real-time cell analysis (RTCA).

RESULTS

As indicated by BrdU and MTT, curcumin significantly decreased the cell proliferation of five cell lines (HT1080, SW872, SYO1, 1273, and U2197) and the viability of two cell lines (SW872 and SW982). VAE led to significant decreases of proliferation in eight cell lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, 1293, and U2197) and reduced viability in seven STS lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, and 1273). As indicated by RTCA for 160 h, curcumin decreased the CI of all synovial sarcoma cell lines as well as T778 and HT1080. VAE diminished the CI in most of the synovial sarcoma (SW982, SYO1) and liposarcoma (SW872, T778) cell lines as well as HT1080. Primary fibroblasts were not affected adversely by the two compounds in RTCA.

CONCLUSION

Curcumin and VAE can inhibit the proliferation and viability of STS cells.

A peptide-decorated and curcumin-loaded mesoporous silica nanomedicine for effectively overcoming multidrug resistance in cancer cells

A robust peptide-functionalized mesoporous silica nanomedicine loading with curcumin and doxorubicin (DOX/CUR@MSN-Pep) has been successfully constructed to effectively overcome multidrug resistance in cancer cells.

Comparative Study of Different Nano-Formulations of Curcumin for Reversal of Doxorubicin Resistance in K562R Cells

PURPOSE

Curcumin is very well established as a chemo-therapeutic, chemo-preventive and chemo-sensitizing agent in diverse disease conditions. As the isolated pure form has poor solubility and pharmacokinetic problems, therefore it is encapsulated in to several nano-formulations to improve its bioavailability. Here in the current study, we aim to compare different nano-formulations of curcumin for their chemo-sensitizing activity in doxorubicin (DOX) resistant K562 cells.

METHODS

Four different curcumin formulations were prepared namely DMSO assisted curcumin nano-dispersion (CurD, 260 nm), liposomal curcumin (CurL, 165 nm), MPEG-PCL micellar curcumin (CurM, 18 nm) and cyclodextrin encapsulated curcumin (CurN, 37 nm). The formulations were subjected to particle characterizations (size, zeta potential, release studies), followed by biological assays such as cellular uptake, P-gp inhibitory activity and reversal of DOX resistance by co-treatment with DOX.

RESULTS

Curcumin uptake in K562N and K562R cells was mildly reduced when treated with CurL and CurM, while for CurD and CurN the uptake remained equivalent. However, CurL retained P-gp inhibitory activity of curcumin and with a considerable chemo-sensitizing effect but CurM showed no P-gp inhibitory activity. CurN retained above biological activities, but requires a secondary carrier under in vivo conditions.

CONCLUSIONS

From the results, CurM was found to be most suitable for solubilization of curcumin where as CurL can be considered as most suitable nano-formulation for reversal of DOX resistance.

Targeting tumor microenvironment with PEG-based amphiphilic nanoparticles to overcome chemoresistance

Multidrug resistance is one of the biggest obstacles in the treatment of cancer. Recent research studies highlight that tumor microenvironment plays a predominant role in tumor cell proliferation, metastasis, and drug resistance. Hence, targeting the tumor microenvironment provides a novel strategy for the evolution of cancer nanomedicine. The blooming knowledge about the tumor microenvironment merging with the design of PEG-based amphiphilic nanoparticles can provide an effective and promising platform to address the multidrug resistant tumor cells. This review describes the characteristic features of tumor microenvironment and their targeting mechanisms with the aid of PEG-based amphiphilic nanoparticles for the development of newer drug delivery systems to overcome multidrug resistance in cancer cells.

FROM THE CLINICAL EDITOR

Cancer is a leading cause of death worldwide. Many cancers develop multidrug resistance towards chemotherapeutic agents with time and strategies are urgently needed to combat against this. In this review article, the authors discuss the current capabilities of using nanomedicine to target the tumor microenvironments, which would provide new insight to the development of novel delivery systems for the future.

Synergistic effect of cucurbitacin B in combination with curcumin via enhancing apoptosis induction and reversing multidrug resistance in human hepatoma cells

Cucurbitacin B is a plant-derived tetracyclic triterpenoid, which has been used for a variety of cancers, especially human hepatoma. Curcumin, isolated from a plant Curcuma longa also has found the anti-tumor property. In the present study, the synergistic effect of cucurbitacin B and curcumin was studied on BEL7402/5-Fu cells in vitro and BEL7402 tumor-bearing mice in vivo. The synergistic anticancer activity of these two compounds involves the two mechanisms. Firstly, curcumin synergistically enhanced the apoptosis of BEL7402/5-Fu cells induced by cucurbitacin B in the optimal mass ratio of 2:1 (cucurbitacin B:curcumin). The mechanism may result from the cell arresting in different phases of cell cycles and the apoptotic change of ultrastructure in BEL7402/5-Fu cells. Secondly, curcumin reversed the multidrug resistance (MDR) caused by cucurbitacin B in the optimized concentration of 67.9μM (25μg/ml). The mechanism was associated with the P-gp reduction, ΔΨm collapse and mitochondrial colocalization in BEL7402/5-Fu cells. The findings were consistent with the changes of the body weight and tumor volume, caspase3 activation and ATP down-regulation in vivo. In conclusion, cucurbitacin B in the combination with curcumin could serve as a novel, promising approach for human hepatoma.

Curcumin loaded self assembled lipid-biopolymer nanoparticles for functional food applications

The supramolecular nano-assemblies formed by electrostatic interactions of two oppositely charged lipid and polymer have been made and used as nanocarriers for curcumin to address its bioavailability and solubility issues. These curcumin encapsulated nano-supramolecular assemblies were characterized with respect to their size (dynamic light scattering), morphology (TEM, SEM), zeta potential (Laser Doppler Velocimetry), encapsulation efficiency (EE), curcumin loading (CL) etc. Stability of the nano-assemblies was assessed at different storage times as a function of varying pH and temperature. The physicochemical characterization of nano-assemblies was performed using Fourier Transform Infra Red Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The in-vitro antioxidant lipid peroxidation (TBARS), radical scavenging (DPPH, NO, H2O2, reducing power) activity assays of powdered curcumin and nano-encapsulated curcumin were performed. It was found that nano-encapsulated curcumin were roughly spherical in shape, presented high positive zeta potential (>30 mV), monodisperse (polydispersity index <0.3), amorphous in nature, stable in the pH range of 2-6 and have enhanced antioxidant potency in comparison to crystalline curcumin in aqueous media. In conclusion, the curcumin encapsulated nanocarriers system has great potential as functional food ingredient of natural origin.

Efficacy of antioxidants as a Complementary and Alternative Medicine (CAM) in combination with the chemotherapeutic agent doxorubicin

INTRODUCTION

Although doxorubicin (Dox)-induced cardiac toxicity and pegylated liposomal doxorubicin (PLD)-induced hand-foot syndrome (HFS) were reported to be correlated with reactive oxygen species (ROS) generation, there is no effective preventive treatment at present. Therefore, the aim of this study was to investigate whether antioxidants-resveratrol (RSVL), tetrahydroxystilbene glucoside (THSG), curcumin, and the ethanolic extract of Antrodia cinnamomea (EEAC)-have the ability to reduce Dox-induced ROS and have a synergistic anticancer effect with Dox that could prevent those side effects and enhance the efficacy of cancer treatment.

METHODS

3T3 normal cells were used as a model to evaluate the effects of these antioxidants in reducing ROS accumulation. Furthermore, the synergistic anticancer effect of antioxidants with Dox on the MCF-7 breast cancer model was also evaluated.

RESULTS

Pretreatment of cells with RSVL, curcumin, and EEAC increased the cell antioxidant ability by improving the activity of superoxide dismutase (SOD), prevented or limited intracellular damage, and ameliorated the harmful effects of ROS. Additionally, RSVL, curcumin, and EEAC had synergistic effects with Dox against MCF-7 breast cancer cells.

CONCLUSION

RSVL, curcumin, and EEAC have the potential to be clinically applied to prevent cardiac toxicity and HFS and enhance the anticancer efficiency of Dox.

Curcumin is a tight-binding inhibitor of the most efficient human daunorubicin reductase--Carbonyl reductase 1

Curcumin is a major component of the plant Curcuma longa L. It is traditionally used as a spice and coloring in foods and is an important ingredient in curry. Curcuminoids have anti-oxidant and anti-inflammatory properties and gained increasing attention as potential neuroprotective and cancer preventive compounds. In the present study, we report that curcumin is a potent tight-binding inhibitor of human carbonyl reductase 1 (CBR1, Ki=223 nM). Curcumin acts as a non-competitive inhibitor with respect to the substrate 2,3-hexandione as revealed by plotting IC50-values against various substrate concentrations and most likely as a competitive inhibitor with respect to NADPH. Molecular modeling supports the finding that curcumin occupies the cofactor binding site of CBR1. Interestingly, CBR1 is one of the most effective human reductases in converting the anthracycline anti-tumor drug daunorubicin to daunorubicinol. The secondary alcohol metabolite daunorubicinol has significantly reduced anti-tumor activity and shows increased cardiotoxicity, thereby limiting the clinical use of daunorubicin. Thus, inhibition of CBR1 may increase the efficacy of daunorubicin in cancer tissue and simultaneously decrease its cardiotoxicity. Western-blots demonstrated basal expression of CBR1 in several cell lines. Significantly less daunorubicin reduction was detected after incubating A549 cell lysates with increasing concentrations of curcumin (up to 60% less with 50 μM curcumin), suggesting a beneficial effect in the co-treatment of anthracycline anti-tumor drugs together with curcumin.

Piperine potentiates the hypocholesterolemic effect of curcumin in rats fed on a high fat diet

It has previously been demonstrated that curcumin possesses a hypocholesterolemic effect and potentiates numerous pharmacological effects of curcumin, however, the mechanisms underlying this hypocholesterolemic effect and the interaction between curcumin and piperine remain to be elucidated. In the present study, male Sprague-Dawley rats were fed on a high-fat diet (HFD) to establish a hyperlipidemia (HLP) model. Co-administration of curcumin plus piperine was found to decrease the levels of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol in the serum and liver, as well as increase the levels of fecal TC, TG and total bile acid, compared with administration of curcumin alone. Curcumin plus piperine also markedly increased the levels of high-density lipoprotein cholesterol. Furthermore, compared with administration of curcumin alone, administration of curcumin plus piperine resulted in a significant upregulation of the activity and gene expression of apolipoprotein AI (ApoAI), lecithin cholesterol acyltransferase (LCAT), cholesterol 7α-hydroxylase (CYP7A1) and low-density lipoprotein receptor (LDLR). In conclusion, these results indicated that co-administration of curcumin plus piperine potentiates the hypocholesterolemic effects of curcumin by increasing the activity and gene expression of ApoAI, CYP7A1, LCAT and LDLR, providing a promising combination for the treatment of HLP.

Co-delivery of doxorubicin and curcumin by polymeric micelles for improving antitumor efficacy on breast carcinoma

Polymeric micelles co-delivered hydrophilic doxorubicin and hydrophobic curcumin improved cytotoxicity, apoptosis, and cellular uptakein vitroand enhanced antitumor and anti-metastasis activityin vivoon breast carcinoma.