AIM To develop a colon-targeting bioreversible delivery system for β-boswellic acid(BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced colitis in rats.METHODS Synthesis of 4...AIM To develop a colon-targeting bioreversible delivery system for β-boswellic acid(BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced colitis in rats.METHODS Synthesis of 4 co-drugs of BBA with essential amino acids was achieved by CDI coupling, followed by their spectral characterization. In vitro kinetics were studied by HPLC in aqueous buffers, homogenates of gastrointestinal tract and fecal matter. In vivo kinetic studies were performed in Wistar rat plasma, urine and feces. The prodrugs were screened in TNBS-induced colitis modeled Wistar rats. Statistical significance was assumed at P < 0.05, P < 0.01, P < 0.001 when compared with disease controls using one-way and two-way ANOVAs.RESULTS Prodrugs were stable in 0.05 mol/L HCl buffer(p H 1.2) and stomach homogenates. Negligible hydrolysis was observed in phosphate buffer and intestinal homogenates. Substantial release(55%-72% and 68%-86%) of BBA was achieved in rat fecal matter and homogenates of colon. In vivo studies of BBA with L-tryptophan(BT) authenticated colon-specific release of BBA. But, surprisingly substantial concentration of BBA was seen to reach the systemic circulation due to probable absorption through colonic mucosa. Sitespecifically enhanced bioavailability of BBA could be achieved in colon, which resulted in demonstration of significant mitigating effect on TNBS-induced colitis in rats without inducing any adverse effects on stomach, liver and pancreas. Prodrug of BT was found to be 1.7%(P < 0.001) superior than sulfasalazine in reducing the inflammation to colon among all prodrugs tested. CONCLUSION The outcome of this study strongly suggests that these prodrugs might have dual applicability to inflammatory bowel disease and chronotherapy of rheumatoid arthritis.展开更多
AIM To design colon-targeted codrugs of mycophenolic acid(MPA) and aminosugars as a safer option to mycophenolate mofetil(MMF) in the management of inflammatory bowel disease. METHODS Codrugs were synthesized by coupl...AIM To design colon-targeted codrugs of mycophenolic acid(MPA) and aminosugars as a safer option to mycophenolate mofetil(MMF) in the management of inflammatory bowel disease. METHODS Codrugs were synthesized by coupling MPA with aminosugars(D-glucosamine and D-galactosamine) using EDCI coupling. The structures were confirmed by infrared radiation, nuclear magnetic resonance, mass spectroscopy and elemental analysis. The release profile of codrugs was extensively studied in aqueous buffers, upper gastrointestinal homogenates, faecal matter and caecal homogenates(in vitro) and rat blood(in vitro). Anti-colitic activity was assessed in 2,4,6-trinitrobezenesulfonic acid-induced colitis in Wistar rats by the estimation of various demarcating parameters. Statistical evaluation was performed by applying one-way and two-way ANOVA when compared with the disease control.RESULTS The prodrugs resisted activation in HCl buffer(pH 1.2) and stomach homogenates of rats with negligible hydrolysis in phosphate buffer(p H 7.4) and intestinal homogenates. Incubation with colon homogenates(in vitro) produced 76% to 89% release of MPA emphasizing colon-specific activation of codrugs and the release of MPA and aminosugars at the site of action. In the in vitro studies, the prodrug of MPA with D-glucosamine(MGLS) was selected which resulted in 68% release of MPA in blood. in vitro studies on MGLS revealed its colon-specific activation after a lag time of 8 h which could be ascribed to the hydrolytic action of N-acyl amidases found in the colon. The synthesized codrugs markedly diminished disease activity score and revived the disrupted architecture of the colon that was comparable to MMF but superior to MPA. CONCLUSION The significant attenuating effect of prodrugs and individual aminosugars on colonic inflammation proved that the rationale of the codrug approach is valid.展开更多
文摘AIM To develop a colon-targeting bioreversible delivery system for β-boswellic acid(BBA) and explore utility of its prodrugs in 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced colitis in rats.METHODS Synthesis of 4 co-drugs of BBA with essential amino acids was achieved by CDI coupling, followed by their spectral characterization. In vitro kinetics were studied by HPLC in aqueous buffers, homogenates of gastrointestinal tract and fecal matter. In vivo kinetic studies were performed in Wistar rat plasma, urine and feces. The prodrugs were screened in TNBS-induced colitis modeled Wistar rats. Statistical significance was assumed at P < 0.05, P < 0.01, P < 0.001 when compared with disease controls using one-way and two-way ANOVAs.RESULTS Prodrugs were stable in 0.05 mol/L HCl buffer(p H 1.2) and stomach homogenates. Negligible hydrolysis was observed in phosphate buffer and intestinal homogenates. Substantial release(55%-72% and 68%-86%) of BBA was achieved in rat fecal matter and homogenates of colon. In vivo studies of BBA with L-tryptophan(BT) authenticated colon-specific release of BBA. But, surprisingly substantial concentration of BBA was seen to reach the systemic circulation due to probable absorption through colonic mucosa. Sitespecifically enhanced bioavailability of BBA could be achieved in colon, which resulted in demonstration of significant mitigating effect on TNBS-induced colitis in rats without inducing any adverse effects on stomach, liver and pancreas. Prodrug of BT was found to be 1.7%(P < 0.001) superior than sulfasalazine in reducing the inflammation to colon among all prodrugs tested. CONCLUSION The outcome of this study strongly suggests that these prodrugs might have dual applicability to inflammatory bowel disease and chronotherapy of rheumatoid arthritis.
基金Supported by Women Scientist Scheme-A(DST),No.SR/WOS-A/LS-1115/2014
文摘AIM To design colon-targeted codrugs of mycophenolic acid(MPA) and aminosugars as a safer option to mycophenolate mofetil(MMF) in the management of inflammatory bowel disease. METHODS Codrugs were synthesized by coupling MPA with aminosugars(D-glucosamine and D-galactosamine) using EDCI coupling. The structures were confirmed by infrared radiation, nuclear magnetic resonance, mass spectroscopy and elemental analysis. The release profile of codrugs was extensively studied in aqueous buffers, upper gastrointestinal homogenates, faecal matter and caecal homogenates(in vitro) and rat blood(in vitro). Anti-colitic activity was assessed in 2,4,6-trinitrobezenesulfonic acid-induced colitis in Wistar rats by the estimation of various demarcating parameters. Statistical evaluation was performed by applying one-way and two-way ANOVA when compared with the disease control.RESULTS The prodrugs resisted activation in HCl buffer(pH 1.2) and stomach homogenates of rats with negligible hydrolysis in phosphate buffer(p H 7.4) and intestinal homogenates. Incubation with colon homogenates(in vitro) produced 76% to 89% release of MPA emphasizing colon-specific activation of codrugs and the release of MPA and aminosugars at the site of action. In the in vitro studies, the prodrug of MPA with D-glucosamine(MGLS) was selected which resulted in 68% release of MPA in blood. in vitro studies on MGLS revealed its colon-specific activation after a lag time of 8 h which could be ascribed to the hydrolytic action of N-acyl amidases found in the colon. The synthesized codrugs markedly diminished disease activity score and revived the disrupted architecture of the colon that was comparable to MMF but superior to MPA. CONCLUSION The significant attenuating effect of prodrugs and individual aminosugars on colonic inflammation proved that the rationale of the codrug approach is valid.
