Curcumin and its cyclohexanone analogue inhibited human Equilibrative nucleoside transporter 1 (ENT1) in pancreatic cancer cells

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Development of pH-Responsive N-benzyl-N-O-succinyl Chitosan Micelles Loaded with a Curcumin Analog (Cyqualone) for Treatment of Colon Cancer

This work aimed at preparing nanomicelles from N-benzyl-N,O-succinyl chitosan (NBSCh) loaded with a curcumin analog, 2,6-bis((3-methoxy-4-hydroxyphenyl) methylene) cyclohexanone, a.k.a. cyqualone (CL), for antineoplastic colon cancer chemotherapy. The CL-loaded NBSCh micelles were spherical and less than 100 nm in size. The entrapment efficiency of CL in the micelles ranged from 13 to 39%. Drug release from pristine CL was less than 20% in PBS at pH 7.4, whereas the release from CL-NBSCh micelles was significantly higher. The release study of CL-NBSCh revealed that around 40% of CL content was released in simulated gastric fluid at pH 1.2; 79 and 85% in simulated intestinal fluids at pH 5.5 and 6.8, respectively; and 75% in simulated colonic fluid at pH 7.4. CL-NBSCh showed considerably high selective cytotoxicity towards mucosal epithelial human colon cancer (HT-29) cells and lower levels of toxicity towards mouse connective tissue fibroblasts (L929). CL-NBSCh was also more cytotoxic than the free CL. Furthermore, compared to free CL, CL-NBSCh micelles were found to be more efficient at arresting cell growth at the G2/M phase, and induced apoptosis earlier in HT-29 cells. Collectively, these results indicate the high prospective potential of CL-loaded NBSCh micelles as an oral therapeutic intervention for colon cancer.

Co-Delivery Using pH-Sensitive Liposomes to Pancreatic Cancer Cells: the Effects of Curcumin on Cellular Concentration and Pharmacokinetics of Gemcitabine

PURPOSE

PEGylated pH-sensitive liposomes (PSL) dual-loaded with gemcitabine and curcumin were investigated for the potential application in gemcitabine-resistant pancreatic ductal adenocarcinoma (PDAC) treatment. Curcumin was employed as an inhibitor of the efflux transporter, multidrug resistance protein 5 (MRP5) in PDAC cells.

METHODS

Liposomes were prepared with gemcitabine in the core and curcumin in the bilayers. The effects of curcumin on pH-sensitivity and 'endosome escape' of PSL with different PEGylation were investigated using a calcein self-quench assay. The effects of curcumin on intracellular gemcitabine concentrations, and cytotoxicity to a MIA PaCa-2 PDAC cell line was evaluated. The pharmacokinetics were investigated in rats following intravenous injection.

RESULTS

The addition of curcumin to the PSL bilayers (0.2-1 mol%)slightly decreased the pH-sensitivity of PSL, but to a less extent than PEGylation (0-5 mol%). Co-treatment with curcumin increased gemcitabine cellular accumulation in a concentration-dependent manner, and resulted in synergistic cytotoxicity towards MIA PaCa-2cells.Both these effects were augmented by the use of PSL, particularly when the two drugs were co-loaded in PSL. In rats, the dual-drug loaded PSL produced significantly reduced (p < 0.05) plasma clearance (CL) and volume of distribution (V_d) for both drugs, alongside 3 to 4-fold increases in the area-under-the-concentration-time curves compared to the free drugs. Additionally, curcumin slightly increase the plasma concentrations of gemcitabine possibly also via the MRP5 inhibition effect.

CONCLUSION

Co-delivery of curcumin with gemcitabine using PSL not only increased the intracellular gemcitabine concentration thus cytotoxicity to MIA PaCa-2 cells but also significantly improved the pharmacokinetic profiles for both drugs. Graphical Abstract.

Therapeutic effect of curcumin in gastrointestinal cancers: A comprehensive review

Gastrointestinal (GI) cancers with a high global prevalence are a leading cause of morbidity and mortality. Accordingly, there is a great need to develop efficient therapeutic approaches. Curcumin, a naturally occurring agent, is a promising compound with documented safety and anticancer activities. Recent studies have demonstrated the activity of curcumin in the prevention and treatment of different cancers. According to systematic studies on curcumin use in various diseases, it can be particularly effective in GI cancers because of its high bioavailability in the gastrointestinal tract. Nevertheless, the clinical applications of curcumin are largely limited because of its low solubility and low chemical stability in water. These limitations may be addressed by the use of relevant analogues or novel delivery systems. Herein, we summarize the pharmacological effects of curcumin against GI cancers. Moreover, we highlight the application of curcumin's analogues and novel delivery systems in the treatment of GI cancers.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

Synthesis and in-vitro anti-cancer evaluations of multi-methoxylated asymmetrical diarylpentanoids as intrinsic apoptosis inducer against colorectal cancer

In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.

Curcuminoids: Implication for inflammation and oxidative stress in cardiovascular diseases

It has been extensively verified that inflammation and oxidative stress play important roles in the pathogenesis of cardiovascular diseases (CVDs). Curcuminoids, from the plant Curcuma longa, have three major active ingredients, which include curcumin (curcumin I), demethoxycurcumin, and bisdemethoxycurcumin. Curcuminoids have been used in traditional medicine for CVDs' management and other comorbidities for centuries. Numerous studies had delineated their anti-inflammatory, antioxidative, and other medicinally relevant properties. Animal experiments and clinical trials have also demonstrated that turmeric and curcuminoids can effectively reduce atherosclerosis, cardiac hypertrophy, hypertension, ischemia/reperfusion injury, and diabetic cardiovascular complications. In this review, we introduce and summarize curcuminoids' molecular and biological significance, while focusing on their mechanistic anti-inflammatory/antioxidative involvements in CVDs and preventive effects against CVDs, and, finally, discuss relevant clinical applications.

Asymmetrical meta-methoxylated diarylpentanoids: Rational design, synthesis and anti-cancer evaluation in-vitro

In the present study, a series of forty-five asymmetrical meta-methoxylated diarylpentanoids have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential. Among the forty-five analogs, three compounds (20, 33 and 42) have been identified as lead compounds due to their excellent inhibition against five human cancer cell lines including SW620, A549, EJ28, HT1080 and MCF-7. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-oxygenated phenyl ring played a critical role in enhancing their cytotoxic effects. Compounds 33 and 42 in particular, exhibited strongest cytotoxicity against tested cell lines with the IC₅₀ values ranging from 1.1 to 4.3 μM. Subsequent colony formation assay on SW620 cell line showed that both compounds 33 and 42 possessed strong anti-proliferative activity. In addition, flow cytometry based experiments revealed that these compounds could trigger intracellular ROS production thus inducing G2/M-phase cell arrest and apoptosis. All these results suggested that poly meta-oxygenated diarylpentnoid is a promising scaffold which deserved further modification and investigation in the development of natural product-based anti-cancer drug.