Enhancement of astaxanthin incorporation by pulsed high-intensity ultrasound in LPS-stimulated macrophages

Abstract

Purpose: Ultrasound (US) has been reported to improve the permeability of cell membranes to pharmaceuticals by causing cavitation. Astaxanthin (AX) potently terminates the induction of inflammation, but it has low oral bioavailability, which limits its incorporation in local cells and organs and its therapeutic potential. In this study, we aimed to investigate the contribution of US to AX incorporation to compensate for the limited incorporation of AX, and regulation of the pro-inflammatory factor interleukin-1β (IL-1β) by AX.

Methods: Murine bone marrow-derived macrophages were stimulated by lipopolysaccharide (LPS). After 2 h, cells were treated with 10 μM AX and/or pulsed high-intensity US irradiation. The cells were then incubated for another 3 h and harvested. AX incorporation in cells was measured by absorbance, and the expression of IL-1β was measured by qPCR. All values are expressed as means ± standard error of the mean.

Results: The combination of AX and US significantly increased AX incorporation in cells compared to AX alone (p < 0.05). In addition, this combination further suppressed the expression of IL-1β compared to AX alone (p < 0.05).

Conclusion: Pulsed high-intensity US irradiation combined with AX treatment promoted AX incorporation in cells and enhanced the anti-inflammatory effect on macrophages.

Keywords: Astaxanthin (AX); Inflammation; Pulsed high-intensity ultrasound.