Table 4.
Microbiota-dependent and independent effects of COS on paracellular permeability and/or TJs.
| Treatment Characteristics | [COS] | Model/Experimental Setup | Type of Study | Observed effects on PP and/or TJs | Type of Effect | References |
|---|---|---|---|---|---|---|
| COS (Kitto Life Co., Ltd., Kyungki-do, Seoul, Korea), MW 5–10 kDa, >70% COS content, DD > 70% |
0.5-4 mg/mL | Caco-2 monolayers | In vitro | No effect on TEER nor on [14C] mannitol flux | MID | [253] |
| COS prepared by enzymatic hydrolysis of shrimp shell chitosan, MW 5000 Da, DD > 90%, | 20, 100, 500 μg/mL | LPS-exposed T84 monolayers | In vitro | ↑ TEER (best effect with 100 μg/mL) | MID | [248] |
| TNF-α-exposed T84 monolayers | ||||||
| COS prepared according to [248], MW 5000 Da, DD > 90% | 100 μg/mL | T84 monolayers | In vitro | ↑ TEER/acceleration of TJ re-assembly during Ca2+ assay | MID | [251] |
| TNF-α-exposed T84 monolayers | ↓ FITC-D flux | |||||
| COS (Beijing Zhong Tai He technology (ZTH tech, Beijing, China), MW < 1000 Da, DD > 90%, DP 2–7 | 50–100 μg/mL | TNF-γα-exposed IPEC-J2 monolayers | In vitro | Suppression of ↑ claudin-1 mRNA, tendency to ↓ ZO-1 mRNA concentration-dependently, no effect on TEER | MID | [256] |
| COS (Zhong Tai He Technology (Beijing, China), MW < 1000, DP 2–7, DD > 90% | 800 μg/mL | IPEC-J2 monolayers | In vitro | ↑ TEER concentration-dependently and ↓ FITC-D flux dose-dependently | MID | [249] |
| LPS-exposed IPEC-J2 monolayers | ||||||
| COS (GlycoBio (GlycoBio, Dalian, China), MW 363-1329 Da, DD > 95% HWCOS (Sigma (St. Louis, MO, USA), MW 4000–6000 Da, DD > 90% |
200 μg/mL | DSS-exposed Caco-2 monolayers | In vitro | ↑ occludin protein abundance and mRNA post-challenge (HWCOS less effectively) | MID | [254] |
| COS (GlycoBio (GlycoBio, Dalian, China), MW 363–1329 Da, DD > 95% | 200 mg/kg BW/day | DSS-exposed mice (UC) | In vivo | ↑ occludin protein abundance | Not determined | [259] |
| NACOS prepared as described in [270], DP 2–6, DA = 97% | 200 mg/kg BW/day (1 mg/mL NACOS) | HFD-fed mice (Metabolic syndrome) | In vivo | ↑ ZO-1, occludin mRNA | MD | [270] |
| LMW-COS enzymatically produced as described in [269], DD = 93% LMW-COS-H, MW 879.6 Da LMW-COS-W, MW 360.9 Da |
400 mg/kg BW/day | HFD-fed mice (Obesity-Metabolic syndrome) | In vivo | ↑ ZO-1, occludin mRNA and protein levels (LMW-COS-H) | MD | [269] |
| ↑ occludin mRNA and protein levels (LMW-COS-L) | ||||||
| COS prepared by enzymatic hydrolysis as described by [276], DD = 88%, DP 2–6% | 200 mg/kg BW/day | Loperamide-exposed mice | In vivo | ↑ occludin, claudin-1 mRNA, ↑ ZO-1 and claudin-1 protein levels | MD | [273] |
| COS prepared as described in [268], DD = 88%, DP 2–6 | 200 mg/kg BW/day (1 mg/mL COS) | Leprdb mutation (db/db) mice | In vivo | ↑ occludin protein levels, no effect on ZO-1 | MD | [268] |
| COS23 prepared by enzymatic degradation of COS as described in [277,278] | 4% in drinking water | HFD-fed mice (NAFLD) | In vivo | ↑ ZO-1, ZO-2 mRNA, tendency for ↑ occludin mRNA | MD | [271] |
| COS (MedChem Express, Shanghai, China), MW < 1 kDa, 91.0% COS | 200 mg/kg BW/day (1 mg/mL COS) | Carulein-exposed mice (SAP) | In vivo | ↑ occludin, claudin-1, no effect on ZO-1 abundance, ↓ FITC-Dextran flux | MD | [272] |
| COS, MW 1000–2000 Da, COS content >85% | 30 mg/kg BW/day | Healthy weaned piglets | In vivo | ↓ occludin and ZO-1 mRNA | Not determined | [275] |
| COS prepared by enzymatic hydrolysis as described in [267], DD > 95%, MW ≤ 1000 Da, DP 2–8 | 100 mg/kg BW/day | Healthy weaned piglets | In vivo | ↑ claudin-1 and occludin mRNA (jejunum only) | MD | [267] |
| COS (Zhongkerongxin Biotechnology Co., Ltd., Suzhou, China), MW 1000-2000 Da, COS > 90% | 30 mg/kg BW/day | Healthy broilers | In vivo | ↑ claudin-3 mRNA, no alteration on occludin, claudin-2 and ZO-1 mRNA | Not deter-mined | [274] |
COS, Chitosan oligosaccharides; DSS, Dextran sulfate sodium; FITC-D, Fluorescein isothiocyanate dextran; HFD, High-fat diet; MD, Microbiota-dependent; MID, Microbiota-independent; NAFLD, Non-alcoholic fatty liver disease; PP, Paracellular permeability; TEER, Transepithelial electrical resistance; TJ, Tight junction; UC, Ulcerative colitis.