Phycocyanin attenuates X-ray-induced pulmonary inflammation via the TLR2-MyD88-NF-κB signaling pathway

Abstract

Phycocyanin (PC), a natural algal protein, is reported for having anti-oxidant and antiinfl ammatory properties. We investigated its ability to attenuate lung infl ammation in mice subjected to X-ray radiation. Male C57BL/6 mice were assigned to the control, total body irradiation, PC pretreatment, and PC treatment groups. Mice in the PC pretreatment group were gavaged with 200 mg/kg PC for 7 consecutive days before irradiation, and those in the PC treatment group were gavaged with 200 mg/kg PC for 7 consecutive days after irradiation. Lungs were collected on Day 7 after irradiation exposure. Hematoxylin and eosin staining of mouse lung sections showed considerable infl ammation damage 7 days after irradiation compared with the control lung but a reduction in pathological injury in the PC treatment group. Pretreatment or treatment with PC signifi cantly decreased levels of interleukin-6 and tumor necrosis factor-α in the lung, and also increased the relative mRNA expression of superoxide dismutase and glutathione. In vivo, PC signifi cantly reduced the expression of Toll-like receptor TLR2, myeloid diff erentiation primary response Myd88, and nuclear factor NF-κB, at both the transcriptional and translation level. Taken together, these data indicated that PC attenuated lung infl ammatory damage induced by radiation by blocking the TLR2-MyD88-NF-κB signaling pathway. Therefore, PC could be a protective agent against radiation-induced infl ammatory damage in normal tissues.

Phycocyanin ameliorates mouse colitisviaphycocyanobilin-dependent antioxidant and anti-inflammatory protection of the intestinal epithelial barrier

“…Phycocyanin has been well documented to exert antiinflammatory effects by inhibiting NF-κB activation in a variety of animal and cellular models of inflammation. [39][40][41] In the present study, PCB showed an equivalent potency to phycocyanin against NF-κB activation and downstream inflammatory responses in human intestine and RAW264.7 cells (Fig. 6, 7b and d), suggesting the critical structural role of PCB in phycocyanin's anti-inflammatory activity.…”

Nicotinamide Riboside and Phycocyanin Oligopeptides Affect Stress Susceptibility in Chronic Corticosterone-Exposed Rats

“…Analogously, PC supplementation boosts antioxidant enzyme levels in the liver and alleviates hepatic oxidative stress due to its radical scavenging, lipid peroxidation prevention [35], and mitochondrial respiratory complex protective activity [36]. The anti-inflammatory ability of PC may stem from its inhibitory action on activating programmed cell death five protein (PCDP5)/nuclear factor κ-B or tool-like receptor 2/NF-κ-B pathways [37,38].…”