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Curcumin, a yellow pigment present in the spice turmeric ( Curcuma longa ), has been linked with various bioactivities, but its optimum potential is limited by its lack of dispersibility in aqueous solvents and poor oral bioavailability. Here, we employed a protein-based nanoparticle approach to improve bioactivity and bioavailability. Curcumin was encapsulated with 95.94% efficiency in biodegradable nanoparticulate formulation based on rice bran albumin (RBA). The mean particle diameter and ζ -potential of curcumin-loaded RBA nanoparticles (Cur-RBA-NPs) were 120 nm and −36.3 mV, respectively. The in vitro bioactivity and in vivo bioavailability of Cur-RBA-NPs were evaluated. The results indicated that the in vitro bioactivities (antioxidant activity, anti-inflammatory activity, and anti-proliferative activity on tumor cells) of Cur-RBA-NPs were superior to those of free curcumin, respectively. Moreover, Cur-RBA-NPs significantly enhanced the bioavailability of curcumin in rats as compared with free curcumin. Besides, the results clearly indicated the promise of RBA-based nanoparticles for oral delivery of poorly bioavailable molecules like curcumin. [ABSTRACT FROM AUTHOR]

Water soluble curcumin nanoparticles (Cur-Ps) were prepared by the simple anti-solvent nanoprecipitation method, using soluble soybean polysaccharide (SSPS) and zein hydrolysate (ZH) as carriers, and the synergistic effect of SSPS and ZH in prepration of Cur-Ps was studied. We expect to provide a new carrier for preparation of Cur-Ps with excellent colloid and oxidation stability. Attributed to poor water solubility of curcumin, the solution of curcumin monomers in deionized water was very turbid. However, the existence of ZH or ZH-SSPS solubilized the curcumin tremendously. The solutions of ZH and ZH-SSPS containing curcumin were yellow and highly transparent. The solubilization results shown that the water solubility of curcumin in ZH solution could reach up to 135, üg/mL when the concentration of ZH was above 2.5 mg/mL, and the addition of SSPS had no effect on the water solubility of curcumin at this concentration. But, when the concentration of ZH was below 2.5 mg/mL, the water solubility of curcumin was enhanced slightly with the addition of SSPS. In pure SSPS solution with a concentration of 3 mg/mL, the solubility of curcumin was only 90, üg/mL, obviously lower than that in ZH solution with the same concentration. These results suggested that ZH plays a leading role in curcumin solubilization in the ZH-SSPS mixture system and this solubiliazation should attributed to the non-covalent interactions between ZH and curcumin, which leading to the formation of ZH-curcumin nanocomplex. Colloidal stability results indicated that at low ionic strength (< 50 mmol/L) or under neutral condition (pH value 7.0), the existence of SSPS had no influence on the particle size distribution of Cur-Ps. However, since SSPS can increase the stability of the protein under acidic and salt-containing solutions, compared with Cur-Ps prepared by ZH only, Cur-Ps fabricated by ZH-SSPS had better colloid stability in solutions with low pH value (4.5 or 2.0) or high ionic strength (>200 mmol/L). Hence, due to the synergistic effect of ZH and SSPS, the curcumin-loaded nanoparticles with small size (< 100 nm) and good colloidal stability can be fabricated. The vitro release study in ethanol-water two-phase system indicated that both Cur-Ps prepared by ZH only and ZH-SSPS solutions had controlled-release effect on curcumin. However, Cur-Ps prepared by ZH-SSPS had better controlled-release effect, and its cumulative release ratio was below 80% in 6 h. The counterpart prepared by ZH only was above 85%. The study on the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical oxidation stability of curcumin nanoparticles indicated that the stability of the curcumin was significantly (P<0.05) improved after the nano-capsulation by ZH or ZH-SSPS. This result is mainly due to the shielding effect for curcumin nano-canpsulation as well as the strong antioxidant effect of ZH. The lyophilized Cur-Ps powder prepared by ZH-SSPS had a multihole spongy structure in field emission images by scanning electron microscopy (SEM), which resulted in its redispersibility as high as 90%, showing a significant (P<0.05) improvement compared with the Cur-Ps fabricated by ZH only. Besides, using ZH-SSPS to prepare Cur-Ps powder had a more curcumin content compared with the counterpart. In conclusion, owing to the synergistic effect between ZH and SSPS, ZH-SSPS is expected to be a new material for the preparation of water soluble Cur-Ps. Due to the transparent appearance of the Cur-Ps solution, it has a good prospect in preparation of curcumin-enriched functional drinks. [ABSTRACT FROM AUTHOR]

Systemic chemotherapy is still the primary treatment for advanced-stage nasopharyngeal carcinoma (NPC), but only limited therapeutic success has been achieved in the past decade because of drug resistance and systemic toxicity. Curcumin (Cur) is an effective alternative to chemotherapeutics because it showed remarkable therapeutic potential in the treatment of NPC. However, lack of tissue specificity and poor penetration in solid tumors are the major obstacles to effective therapy. Therefore, in this work, a self-assembled sub-30 nm therapeutic lipid nanoparticle loaded with Cur, named as Cur@α-NTP-LN, was constructed, specifically targeting scavenger receptor class B member 1 (SR-B1) and enhancing its therapeutic effects on NPC in vivo. Our results showed that Cur@α-NTP-LNs were effective and superior to free Cur on NPC cell-specific targeting, suppressing cell proliferation and inducing cell apoptosis. In vivo and ex vivo optical imaging revealed that Cur@α-NTP-LNs exerted high targeting efficiency, specifically accumulating in NPC xenograft tumors and delivering Cur into the tumor center after systemic administration. Furthermore, Cur@α-NTP-LNs exhibited a remarkable inhibitory effect on the growth of NPC subcutaneous tumors, with over 71 and 47% inhibition compared to Cur- and α-NTP-LNs-treated groups, respectively. In addition, Cur@α-NTP-LNs almost blocked NPC metastasis in a lung metastasis model of NPC and significantly improved the survival rate. Thus, the sub-30 nm Cur@α-NTP-LNs enhanced the solubility of Cur and demonstrated the ability of targeted Cur delivery into the center of the solid NPC tumor, performing synergistic inhibitory effects on the growth of NPC tumor and its metastasis with high efficiency. [ABSTRACT FROM AUTHOR]

Summary: In this study, we aimed to evaluate the potential of the γ‐zein hydrolysate (γ‐ZH) as a new delivery system for hydrophobic bioactive molecules such as curcumin (Cur). γ‐ZH‐Cur complexes (γ‐ZH‐Cur) with a particle size of 50–60 nm were successfully formed via the hydrogen bonding and hydrophobic interactions. Compared to α‐ZH, the complexation of Cur in γ‐ZH showed a better improvement in the water solubility and physicochemical stability of Cur and showed sustained release and greater potential for absorption of Cur. The differences in the loading capability, the physicochemical storage and the bioaccessibility of Cur between γ‐ZH and α‐ZH may be associated with the differences in the amino acid composition and typical sequence of peptides. These results indicate that γ‐ZH has a better ability to serve as a novel delivery for the hydrophobic bioactive molecules compared to α‐ZH. [ABSTRACT FROM AUTHOR]

The present work was aimed to evaluate the potential of the gel-like Pickering emulsions (50%, v/v, oil) stabilised by zein/tannic acid (TA) complex colloidal particles (ZTPE) as a new encapsulation system of lipophilic ingredients. Compared with sodium caseinate-stabilised emulsions (SCE) and bulk oil, the better protective effects of ZTPE on the chemical stability of curcumin were observed when they suffered from UV light, and the lipid oxidation rate remarkably reduced in ZTPE. Also, the zein particle layers loaded with TA around the oil droplets can provide protection against harsh gastric environment, facilitating to slow down the release of free fatty acids (FFA) and curcumin during in vitro simulated digestion. These findings show that ZTPE have a good potential to act as an efficient encapsulating agent to protect functional ingredients from degradation and control their release during digestion, which can further improve the bioavailability of bioactive ingredients. [ABSTRACT FROM AUTHOR]