Different wavelengths of LED irradiation promote secondary metabolite production in Pycnoporus sanguineus for antioxidant and immunomodulatory applications.

Pycnoporus sanguineus is a fungus of the phylum Basidiomycota that has many applications in traditional medicine, modern pharmaceuticals, and agricultural industries. Light plays an essential role in the metabolism, growth, and development of fungi. This study evaluated the mycelial growth and antioxidant and anti-inflammatory activities in P. sanguineus fermentation broth (PFB) cultured under different wavelengths of LED irradiation or in the dark. Compared to the dark cultures, the dry weight of mycelia in red- and yellow-light cultures decreased by 37 and 35% and the yields of pigments increased by 30.92 ± 2.18 mg and 31.75 ± 3.06 mg, respectively. Compared with the dark culture, the DPPH free radical scavenging ability, ABTS+ free radical scavenging capacity, and reducing power of yellow-light cultures increased significantly, and their total phenolic content peaked at 180.0 ± 8.34 µg/mL. However, the reducing power in blue-light cultures was significantly reduced, though the total phenol content did not vary with that of dark cultures. In LPS- and IFN-γ-stimulated RAW 264.7 cells, nitrite release was significantly reduced in the red and yellow light-irradiated PFB compared with the dark culture. In the dark, yellow-, and green-light cultures, TNF-α production in the inflamed RAW 264.7 cells was inhibited by 62, 46, and 14%, respectively. With red-, blue-, and white-light irradiation, TNF-α production was significantly enhanced. Based on these results, we propose that by adjusting the wavelength of the light source during culture, one can effectively modulate the growth, development, and metabolism of P. sanguineus.

Gum Arabic in combination with IFN-γ promotes the M1 polarization in macrophage.

Gum Arabic, a mixture of polysaccharide and glycoprotein, is used as an emulsifying stabilizer in the food industry. It might have immunomodulatory effects. We hypothesized that the combination of IFN-γ and Gum Arabic promotes the production of pro-inflammatory factors in RAW 264.7 cells. Treatment of RAW 264.7 cells with the combination of 3% Gum Arabic and 40 ng/mL IFN-γ resulted in a drastic increase (320%) in nitric oxide production compared with that induced by IFN-γ alone. PGE-2 was produced after the cells were treated with 3% Gum Arabic and 40 ng/mL IFN-γ for 6 h. Gum Arabic and IFN-γ increased the production of iNOS and COX-2 proteins, and triggered TNF-α release. Apart from TNF-α, the release of both G-CSF and IL-6 increased by more than 100 times. The release of IL-3, RANTES, and IL-10 increased by more than ten times. Gum Arabic and IFN-γ also increased the secretion of IL-10, IL-1α, IL-1ß, IL-13, KC, IL-5, IL-4, IL-12, Eotaxin, IL-9, MCP-1, and ROS. Cytokines associated with M1 polarization of macrophages such as TNF-α, IL-1ß, IL-12, NO, and ROS were induced by Gum Arabic and IFN-γ. Our findings help to explore the inflammatory reaction caused by Gum Arabic in cosmetics.