Preclinical studies of the antitumor effect of curcumin-loaded polymeric nanocapsules: A systematic review and meta-analysis.

Curcumin, a plant-derived compound, has various well-known biological effects (anti-inflammatory, antioxidant, antitumor, among others) as well as some important limitations for formulators, such as poor water solubility and low oral bioavailability. Its nanoencapsulation is reported to overcome these drawbacks and to improve its in vivo efficacy. Here, data from preclinical in vivo studies evaluating the antitumor efficacy of curcumin-loaded polymeric nanocapsules are collected, analyzed, and discussed as a systematic review. Meta-analyses are performed to assess the contribution of this nanoencapsulation compared with nonencapsulated curcumin. Eighteen studies (116 animals) meet the inclusion criteria. The evidence that curcumin-loaded polymeric nanocapsules inhibits tumor growth (SMD: -3.03; 95% CI: -3.84, -2.21; p < 0.00001) and decreases tumor weight (SMD: -3.96; 95% CI: -6.22, -1.70; p = 0.0006) in rodents is established, regardless of the solid tumor model. To assess the quality of the studies included in the review a bias risk analysis was performed using the SYRCLE's RoB tool. Therefore, encapsulation in polymeric nanocapsules represents an important tool to improve the antitumor effects of curcumin, and this systematic review paves the way for future clinical studies and the translation of curcumin formulations into novel nanomedicines for human cancer treatment.

A novel approach to arthritis treatment based on resveratrol and curcumin co-encapsulated in lipid-core nanocapsules: In vivo studies.

Resveratrol and curcumin are two natural polyphenols extensively used due to their remarkable anti-inflammatory activity. The present work presents an inedited study of the in vivo antioedematogenic activity of these polyphenols co-encapsulated in lipid-core nanocapsules on Complete Freund's adjuvant (CFA)-induced arthritis in rats. Lipid-core nanocapsules were prepared by interfacial deposition of preformed polymer. Animals received a single subplantar injection of CFA in the right paw. Fourteen days after arthritis induction, they were treated with resveratrol, curcumin, or both in solution or loaded in lipid-core nanocapsules (1.75 mg/kg/twice daily, i.p.), for 8 days. At the doses used, the polyphenols in solution were not able to decrease paw oedema. However, nanoencapsulation improved the antioedematogenic activity of polyphenols at the same doses. In addition, the treatment with co-encapsulated polyphenols showed the most pronounced effects, where an inhibition of 37-55% was observed between day 16 and 22 after arthritis induction. This treatment minimized most of the histological changes observed, like fibrosis in synovial tissue, cartilage and bone loss. In addition, unlike conventionally arthritis treatment, resveratrol and curcumin co-encapsulated in lipid-core nanocapsules did not alter important hepatic biochemical markers (ALP, AST, and ALT). In conclusion, the strategy of co-encapsulating resveratrol and curcumin in lipid-core nanocapsules improves their efficacy as oedematogenic agents, with no evidence of hepatotoxic effects. This is a promising strategy for the development of new schemes for treatment of chronic inflammation diseases, like arthritis.

Dithranol-loaded lipid-core nanocapsules improve the photostability and reduce the in vitro irritation potential of this drug.

Dithranol is a very effective drug for the topical treatment of psoriasis. However, it has some adverse effects such as irritation and stain in the skin that make its application and patient adherence to treatment difficult. The aims of this work were to prepare and characterize dithranol-loaded nanocapsules as well as to evaluate the photostability and the irritation potential of these nanocarriers. Lipid-core nanocapsules containing dithranol (0.5 mg/mL) were prepared by interfacial deposition of preformed polymer. EDTA (0.05%) or ascorbic acid (0.02%) was used as antioxidants. After preparation, dithranol-loaded lipid-core nanocapsules showed satisfactory characteristics: drug content close to the theoretical concentration, encapsulation efficiency of about 100%, nanometric mean size (230-250 nm), polydispersity index below 0.25, negative zeta potential, and pH values from 4.3 to 5.6. In the photodegradation study against UVA light, we observed a higher stability of the dithranol-loaded lipid-core nanocapsules comparing to the solution containing the free drug (half-life times around 4 and 1h for the dithranol-loaded lipid-core nanocapsules and free drug solution containing EDTA, respectively; half-life times around 17 and 7h for the dithranol-loaded lipid-core nanocapsules and free drug solution containing ascorbic acid, respectively). Irritation test by HET-CAM method was conducted to evaluate the safety of the formulations. From the results it was found that the nanoencapsulation of the drug decreased its toxicity compared to the effects observed for the free drug.