Anti-inflammatory activity of soluble chito-oligosaccharides (CHOS) on VitD3-induced human THP-1 monocytes.

Phornsiri Petsrichuang,Vincent G H Eijsink,Munthipha Khamphio,Paiboon Jitprasertwong,Kuntalee Rangnoi,A M Abd El-Aty,Wanangkan Poolsri,Chatchai Muanprasat,Montarop Yamabhai

doi:10.1371/journal.pone.0246381

Abstract

Chito-oligosaccharides (CHOS) are oligomers of D-glucosamine and N-acetyl-glucosamine. Anti-inflammatory activities of a wide variety of CHOS mixtures have previously been reported, mainly based on studies with mouse models and murine macrophages. Since the mouse and human immune systems are quite different, gaining insight into the activity of CHOS on human cell lines, using well-characterized CHOS mixtures, is of considerable interest. Bacillus subtilis chitosanase (BsCsn46A) can efficiently convert chitosan to mixtures of water soluble low molecular weight CHOS. Here, the anti-inflammatory activity of a properly characterized CHOS mixture was studied, using human THP-1 cells that were differentiated to mature monocytes using vitamin D3. Addition of CHOS reduced the production of multiple pro-inflammatory cytokines associated with bacterial lipopolyssacharide (LPS)-stimulated inflammation, in a dose-dependent manner and without affecting cell viability. Interestingly, only minimal effects of CHOS were observed in similar experiments with phorbol 12-myristate 13-acetate- (PMA-) differentiated, macrophage-like, THP-1 cells. Altogether, in addition to showing promising biological effects of well-characterized low molecular weight soluble CHOS in a human system, the present study also points at Vitamin D3-stimulated THP-1 cells as a favorable system for assessing the anti-inflammatory activity of bioactive compounds.

Highlights

Chitosan, a deacetylated form of chitin, which is the main structural component of the exoskeletons of arthropods and fungi, can be considered as one of the most promising biomaterials of the 21st century [1]
For phorbol 12-myristate 13-acetate- (PMA-)induced THP-1 cells, after 48 h, the plate was centrifuged at 700 x g for 5 min, after which the Phorbol 12-myristate 13-acetate (PMA)-containing medium was replaced with fresh Roswell Park Memorial Institute (RPMI), and the plate was incubated for another 24 h at 37 ̊C, 5% CO2 before a challenging experiment was initiated
The reaction was carried out in 100 mL scale and with multiple additions of higher amounts of enzyme to ensure that the chitosan substrate was completely converted to soluble CHOS

Summary

Introduction

A deacetylated form of chitin, which is the main structural component of the exoskeletons of arthropods and fungi, can be considered as one of the most promising biomaterials of the 21st century [1] This is because chitosan and its derivatives possess diverse biological. Among the chitin-derived products, chitosan oligosaccharides (CHOS or COS) are highly attractive due to multiple favorable properties. A well-defined mixture of low molecular weight (0.4–1.4 kDa) soluble CHOS was generated through enzymatic hydrolysis of a highly deacetylated chitosan (FA 0.15) with a previously characterized Bacillus subtilis chitosanase (BsCsnA) [16]

Materials and methods

Results and discussion

Conclusion