Chitin and Chitosan Derivatives as Biomaterial Resources for Biological and Biomedical Applications

Chitin is a long-chain polymer of N-acetyl-glucosamine, which is regularly found in the exoskeleton of arthropods including insects, shellfish and the cell wall of fungi. It has been known that chitin can be used for biological and biomedical applications, especially as a biomaterial for tissue repairing, encapsulating drug for drug delivery. However, chitin has been postulated as an inducer of proinflammatory cytokines and certain diseases including asthma. Likewise, chitosan, a long-chain polymer of N-acetyl-glucosamine and d-glucosamine derived from chitin deacetylation, and chitosan oligosaccharide, a short chain polymer, have been known for their potential therapeutic effects, including anti-inflammatory, antioxidant, antidiarrheal, and anti-Alzheimer effects. This review summarizes potential utilization and limitation of chitin, chitosan and chitosan oligosaccharide in a variety of diseases. Furthermore, future direction of research and development of chitin, chitosan, and chitosan oligosaccharide for biomedical applications is discussed

Piperine as potential therapy of post-weaning porcine diarrheas: an in vitro study using a porcine duodenal enteroid model

Abstract Post-weaning diarrhea in piglets is a major problem, resulting in a significant loss in pig production. This study aimed to investigate the effects of piperine, an alkaloid abundantly found in black peppers, on biological activities related to the pathogenesis of post-weaning diarrhea using a porcine duodenal enteroid model, a newly established intestinal stem cell-derived in vitro model recapitulating physiology of porcine small intestinal epithelia. Porcine duodenal enteroid models were treated with disease-relevant pathological inducers with or without piperine (8 μg/mL and/or 20 μg/mL) before measurements of oxidative stress, mRNA, and protein expression of proinflammatory cytokines, nuclear factor-kappa B (NF-κB) nuclear translocation, barrier leakage, and fluid secretion. We found that piperine (20 μg/mL) inhibited H2O2-induced oxidative stress, TNF-α-induced mRNA, and protein expression of proinflammatory cytokines without affecting NF-κB nuclear translocation, and prevented TNF-α-induced barrier leakage in porcine duodenal enteroid monolayers. Importantly, piperine inhibited fluid secretion induced by both forskolin and heat-stable toxins (STa) in a three-dimensional model of porcine duodenal enteroids. Collectively, piperine possesses both anti-inflammatory and anti-secretory effects in porcine enteroid models. Further research and development of piperine may provide novel interventions for the treatment of post-weaning porcine diarrhea

Chemical structures of inhibitors of glutathione efflux transporters and CFTR expression in human erythrocytes.

<p>(A) Chemical structures of GlyH-101, a CFTR inhibitor, and MK571, a MRP1 inhibitors. (B) Expression of CFTR in erythrocytes of beta thalassemia/Hb E patients and normal healthy subjects.</p

Effect of GlyH-101 on H₂O₂-induced osmotic tolerance of beta thalassemia/Hb E erythrocytes.

<p>The erythrocytes were incubated with PBS containing H₂O₂ (10 mM) with or without GlyH-101 (50 µM) at 37°C for 3 h in a shaking incubator. After centrifugation and removal of supernatant, cells were exposed to hypotonic solution (85% PBS) and centrifuged at 1,500 g at 4°C for 10 min. Absorbance of the supernatants was measured at 540 nm. Data were expressed as means ± S.E. *, p<0.05 compared with H₂O₂-treated group (n = 10).</p

Anti-oxidative properties of MK571 in erythrocytes of beta thalassemia/Hb E patients.

<p>(A) MK571 reduced H₂O₂-induced free radical production. Erythrocytes loaded with DCFH-DA were incubated for 1 h with DMSO (basal), DMSO plus MK571 (basal + MK571), H₂O₂ (10 mM), H₂O₂ plus MK571 (50 µM) or H₂O₂ plus MK571 and GlyH-101 (50 µM). Reactive oxygen species were measured by flow cytometry analysis at excitation wavelength of 490 nm and emission wavelength of 530 nm. Data were expressed as means ± S.E. *, p<0.05; **, p<0.001 compared with H₂O₂-treated group (n = 12). (B) Effect of MK571 on intracellular glutathione levels. Erythrocytes were treated for 1 h without (basal) or with H₂O₂ (10 mM) in the presence or absence of MK571 (50 µM) or MK571 plus GlyH-101 (50 µM) before measurements of GSH levels. Data were expressed as means ± S.E. NS, non-statistical significant difference from basal control; *, p<0.01 compared with basal control; #, p<0.05; ##, p<0.01 compared with H₂O₂-treated group (n = 8).</p