Curcumin (CU) has shown broad anti-cancer effects. 5-fluorouracil (5-FU) has been a conventional chemotherapeutic agent for hepatocellular carcinoma. Unfortunately, the nonspecific cytotoxicity and multidrug resistance caused by long-term use limited the clinical efficacy of 5-FU. This study was aimed to investigate whether the combination of CU and 5-FU could generate synergistic effect in inhibiting the human hepatocellular carcinoma. The results of cytotoxicity test showed that compared with applying single drugs, the combination of CU and 5-FU (1:1, 1:2, 1:4, 2:1 and 4:1, mol/mol) presented stronger cytotoxicity in SMMC-7721, Bel-7402, HepG-2 and MHCC97H cells, while the combination groups are relatively insensitive to normal hepatocytes (L02). Among them, the molar ratio of 2:1 combination group showed strong synergistic effect in SMMC-7721cells. Then, western blotting assay further verified that the mechanism of the synergistic effect may be related to the inhibition of the expression of NF-κB (overall) and COX-2 protein. In addition, the synergistic effect was also validated in the xenograft mice in vivo. This research not only provides a novel and effective combination strategy for the therapy of hepatocellular carcinoma but also provides an experimental basis for the development of CU and 5-FU compound preparation.

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This study investigated the effect of structural modification of Curcumin (CU) combined with the solid lipid nanoparticles (SLN) drug delivery system on anti-tumor activity in vitro . A new structure of Curcumin derivative (CU1) was successfully synthesized by modifying the phenolic hydroxyl group of CU. CU1 was two times more stable than CU at 45 °C or constant light. The SLN containing CU1 (CU1-SLN) was prepared, and the particle size, polydispersity index, entrapment efficiency, drug loading, and zeta potential of CU1-SLN were (104.1 ± 2.43) nm, 0.22 ± 0.008, (95.1 ± 0.38) %, (4.28 ± 0.02) %, and (28.3 ± 1.60) mV, respectively. X-ray diffraction (XRD) and Differential scanning calorimetry (DSC) showed that CU1 is amorphous in SLN. CU1-SLN released the drug slowly for 48 h, while CU and CU1 were released rapidly within 8 h. In terms of cytotoxicity, CU1 exhibited a 1.5-fold higher inhibition than CU against A549 and SMMC-7721 cells, while CU1-SLN showed 2-fold higher inhibition than CU1. Both CU1 and CU1-SLN reduced the toxicity in normal hepatocytes compared with CU (2.6-fold and 12.9-fold, respectively). CU1-SLN showed a significant apoptotic effect ( p < 0.05). In summary, CU1 retained the inhibitory effect of CU against tumor cells, while improving stability and safety. Additionally, CU1-SLN presents a promising strategy for the treatment of liver and lung cancer.

Malignant tumor endangers seriously the health of all mankind. Multidrug resistance (MDR) is one of the main causes of clinical tumor chemotherapy failure. Curcumin (CUR) has not only antitumor activity but also reversing tumor MDR effect. CUR reverses tumor MDR via regulating related signal pathways or corresponding expressed proteins or gene. When combined with chemotherapeutic agents, CUR can be a chemotherapeutic sensitive agent to enhance chemotherapy efficacy and weaken tumor MDR. On the other hand, to improve the MDR reversal effect of CUR, its derivatives have been extensively studied. Therefore, this article mainly focuses on reviewing the application of CUR and its derivatives in MDR and its mechanism of reversing MDR.

Purpose The objective of this study was to develop long-circulating solid lipid nanoparticles (LSLN) containing a novel curcumin (CU) derivative (CU1), to improve CU1ʹs pharmacokinetic behavior and its anti-cancer effects in MHCC-97H liver cancer cells. Methods LSLN loaded with CU1 (CU1-LSLN) was optimized and characterized. The cell biological properties and the anti-cancer mechanism of CU1-LSLN on MHCC-97H cells were evaluated by MTT, flow cytometry, Transwell, and Western blot. CU1-LSLN was further evaluated for pharmacokinetic behavior, biodistribution, and liver toxicity in SD rats. Results The optimized CU1-LSLN formulation showed the ideal particle size (PS), polydispersity index (PDI), zeta potential (ZP), encapsulation efficiency (EE%), and drug loading (DL%) of 122.10 ± 6.63 nm, 0.19 ± 0.02, −36.30 ± 1.25 mV, 94.98 ± 0.90% and 4.53 ± 0.69%, respectively. X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectrometry (FTIR) indicated that CU1 was well encapsulated by LSLN and existed in amorphous form. Storage stability of CU1-LSLN was up to 180 days with a sustained-release of drug over 96 h. The uptake efficiency of CU1-LSLN to MHCC-97H cells was 3.24 and 2.98 times higher than that of CU and CU1 after treatment for 3 h, which helped to enhance the inhibitive effect of CU1-LSLN on the proliferation, migration, and invasion potential of MHCC-97H cells and increased its ability to promote apoptosis. Meanwhile, the expression levels of NF-κB, COX-2, MMP-2, MMP-9, and uPA decreased significantly. In vivo, CU1-LSLN prolonged the retention time of the drug, the area under the curve (AUC) increased significantly (CU: 69.9-fold, CU1: 85.9-fold), and no significant liver toxicity was observed. Conclusion CU1-LSLN is a novel preparation with great potential for treating liver cancer.