Characterization of brusatol self-microemulsifying drug delivery system and its therapeutic effect against dextran sodium sulfate-induced ulcerative colitis in mice

Drug Deliv. 2017 Nov;24(1):1667-1679. doi: 10.1080/10717544.2017.1384521.

Abstract

Brusatol (BR) is one of the main bioactive components derived from Brucea javanica, a medicinal herb historically used in the treatment of dysenteric disorders (also known as ulcerative colitis(UC)). Due to its poor aqueous solubility, a novel brusatol self-microemulsifying drug delivery system (BR-SMEDDS) nanoformulation with smaller size, higher negative zeta potential and drug content, and excellent stability was developed. The appearance of BR-SMEDDS remained clear and transparent, and transmission electron microscopy showed microemulsion droplets to be spherical with homogeneous distribution. Pharmacokinetic parameters indicated that oral bioavailability was greatly improved by BR-SMEDDS as compared with aqueous suspension. Meanwhile, the anti-colitis activity of BR-SMEDDS was evaluated on dextran sodium sulfate (DSS)-induced colitis mice model. The result illustrated that the nano-formation significantly reduced the body weight loss, recovered colon length, decreased disease activity index and microscopic score, regulated immune-inflammatory cytokines, diminished oxidative stress and repressed the colonic expression of myeloid differentiation factor 88 (MyD88), toll-like receptor 4 (TLR4) and nuclear factor kappa B p65 (NF-κB p65) proteins. Our findings demonstrated for the first time that BR could effectively attenuate colonic inflammation in mice, at least partially, via favorable regulation of anti-oxidative and anti-inflammatory status and inhibition of the TLR4-linked NF-κB signaling pathway. The BR nano-formulation was superior to BR suspension and sulphasalazine, in treating experimental UC, and exhibited similar effect with azathioprine, with much smaller dosage. The enhanced anti-UC effect of BR might be intimately associated with the improved pharmacokinetic property by SMEDDS. The developed nano-delivery system might thus be a promising candidate for colitis treatment.

Keywords: Brusatol; anti-colitis activity; anti-inflammation; in vitro and in vivo evaluation; self-microemulsifying drug delivery system.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Chemistry, Pharmaceutical / methods
  • Colitis, Ulcerative / chemically induced*
  • Colitis, Ulcerative / drug therapy*
  • Colitis, Ulcerative / metabolism
  • Dextran Sulfate / pharmacology*
  • Disease Models, Animal
  • Drug Delivery Systems / methods
  • Inflammation / chemically induced
  • Inflammation / drug therapy
  • Inflammation / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Myeloid Differentiation Factor 88 / metabolism
  • NF-kappa B / metabolism
  • Quassins / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Toll-Like Receptor 4 / metabolism

Substances

  • Anti-Inflammatory Agents
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • Quassins
  • Toll-Like Receptor 4
  • brusatol
  • Dextran Sulfate

Grants and funding

This work was supported by grants from National Natural Science Foundation of China (No. 81503202), Science and Technology Planning Project of Guangdong Province, China (No. 2012B09060007, 2013B090600007, 2013B090800052, 2013B090600010, 2014A020221042 and 2017A050506044), Hongkong, Macao and Taiwan Science & Technology Cooperation Program of China (No. 2014DFH30010), Guangdong International Cooperation Project (No. 2013508102016), Science and Technology Major Project of Guangdong Province (No. 2013A022100001), Natural Science Foundation of Guangdong Province (2015A030310217), Science and Technology Planning Project of Guangzhou, Guangdong, China (201704030028).