Table 2.

Primary Focus of the Included Studies.

Primary Focus	Number of Studies	Reference
General anti-inflammatory effects of hyaluronic acid (HA)	16	Abatangelo et al., 1989 Yasui et al., 1992 Fraser et al., 1993 Noble et al., 1996 Takahashi et al., 2001 Tanimoto et al., 2001 Jean et al., 2006 Wang et al., 2006 Hashizume and Mihara, 2009 Brun et al., 2012 Smith et al., 2013 Chen et al., 2014 Yoshioka et al., 2014 Sundman et al., 2014 Chan et al., 2015 Aulin et al., 2016
High molecular weight HA and small HA oligosaccharides	11	Filion and Phillips, 2001 Lajeunesse et al., 2003 Sheehan et al., 2003 Santangelo et al., 2007 Hashizume et al., 2010 Campo et al., 2012 Campo et al., 2012b Chang et al., 2012 Galois et al., 2012 Kataoka et al., 2013 Sato et al., 2014
Pro-inflammatory macromolecules	7	Yasui et al., 1992 Shimazu et al., 1993 Goto et al., 1999 D’Souza et al., 2000 Stove et al., 2002 Greenberg et al., 2006 Oliviero et al., 2015
CD44 receptor	7	Chow et al., 1993 Kawana et al., 2008 Yasuda, 2010 Levesque et al., 1997 Sasaki et al., 2004 Hiraiwa et al., 2011 Campo et al., 2012a
TLR receptors	3	Scheibner et al., 2006 Campo et al., 2011 Campo et al., 2012c
ICAM-1 receptor	3	Hiramitsu et al., 2006 Yasuda, 2007 Shao et al., 2013
LAYN receptor	1	Murata et al., 2013