A Mixture of Water-Soluble Polysaccharides Reduces Caspase-1 and IL-1β Inflammatory Responses by Cutibacterium acnes in vitro in Reconstructed Human Epidermis (RHE)

The results lend further support to previously reported work which was done on NHEKs treated with ultraviolet B (UVB) light and adenosine triphosphate (ATP) and demonstrate that the same mixture of polysaccharides can have a modulating effect against bacterial and chemical induced inflammation in RHE.

Employing a modification of this in vitro assay, RHE was pretreated with C. acnes for 48 hours, then further treated with a mixture of water-soluble polysaccharides (STRATAPHIX™ POLY, "Polysaccharide Blend") previously shown to reduce inflammasome-mediated inflammatory responses in normal human epidermal keratinocytes (NHEK). Two inflammasome-mediated inflammation markers were tested, including caspase-1, a potent protease enzyme activated by NOD-like receptor protein (NLRP)-induced inflammasome activation, and interleukin-1β (IL-1β), a cytokine which is activated from inactive pro-IL-1β by caspase-1.

The treatment of the RHE tissues with C. acnes for 48 hours elicited an inflammatory response measured with both markers compared against untreated tissues. Treatment of the tissues with 1% and 2% salicylic acid for 24 hours after C. acnes treatment increased the inflammatory response measured with both markers. Application of the water-soluble polysaccharides in combination with 1% and 2% of salicylic acid significantly reduces expression of both active caspase-1 and IL-1β compared against the tissues treated with C. acnes and salicylic acid alone.