structure of phycocyanin
Molecular structure representation of phycocyanin.
Reprinted from Chemosphere, Vol. 192, S. Tan et al., In vitro assessment of the toxicity of lead (Pb2+) to
phycocyanin, pp. 171-177, Copyright (2018), with permission from Elsevier.

Molecular weight: 81-112 KDa (dependent on source)1
CAS number: 11016-15-2

Phycocyanin is a pigment-binding protein from the phycobiliprotein family that is used in food, pharmaceutical, and cosmetic preparations. There are two types of phycocyanin—characteried as C-phycocyanin and R-phycocyanin—that are derived from green and red algae, respectively.2 In algae, phycocyanin serves the role of a light harvesting complex. Its primary use in cosmetics is as a colorant due to its pigment characteristics. In the nutrional supplement industry, spirulina has become a popular due to its high levels of protein. Spirulina comes from the algae, Arthrospira plantensis, which produces C-phycocyanin. Spirulina is reported to have antioxidant properties and also purported as a beneficial agent for cardiovascular health.

There has been considerable interest in the skin care arena to elucidate the possible properties of phycocyanin in treating the skin. In terms of skin whitening, C-phycocyanin was reported as an anti-melanogenic agent that functions by interupting the activity of tyrosinase—the enzyme responsible for two key biosynthetics steps in the formation of melanin.3 There is also interest in developing techniques to encapsulate phycocyanin so that it can be delivered to the lower layers of the skin to mitigate inflammation and oxidative stress.4,5 Phycocyanin has also been shown to beneficially modulate apoptotic pathways in skin cells exposed to UV radiation.6 Furthermore, phycocyanin has demonstrated properties in wound healing.7 Overall, there appears to be significant potential in terms of the cosmeceutical properties of phycocyanin.8

Fluorescence: λex = 609 nm, λem = 643 nm in 0.1 M phosphate pH 7.2

1. A. Patel, S. Mishra, R. Pawar, and P.K. Ghosh, Purification and characterization of C-Phycocyanin from cyanobacterial species of marine and freshwater habitat, Protein Expr. Purif., 40, 248-255 (2005).
2. Q. Liu, Y. Huang, R. Zhang, T. Cai, and Y. Cai, Medical application of Spirulina platensis derived C-phycocyanin, Evidence-Based Complementary and Alternative Medicine, 2016, Article ID 7803846 (2016).
3. L.C. Wu, Y.Y. Lin, S.Y. Yang, Y.T. Weng, and Y.T. Tsai, Antimelanogenic effect of c-phycocyanin through modulation of tyrosinase expression by upregulation of ERK and downregulation of p38 MAPK signaling pathways, J. Biomed. Sci., 18, 74 (2011).
4. I. Castangia, M.L. Manca, A. Catalán-Latorre, A.M. Maccioni, A.M. Fadda, and M. Manconi, Phycocyanin-encapsulating hyalurosomes as carrier for skin delivery and protection from oxidative stress damage, J. Mater. Sci. Mater. Med., 27, 75- (2016).
5. M. Manconia, J. Pendás, N. Ledón, T. Moreira, C. Sinico, L. Saso, and A.N. Fadda, Phycocyanin liposomes for topical anti-inflammatory activity: in- vitro in-vivo studies, J. Pharm. Pharmacol., 61, 423-430 (2009).
6. K.M. Kim, J.Y. Lee, A.R. Im, and S. Chae, Phycocyanin protects against UVB-induced apoptosis through the PKC α/βII-Nrf-2/HO-1 dependent pathway in human primary skin cells, Molecules, 23, 478 (2018).
7. C.S. Gur, D.K. Erdogan, I. Onbasılar, P. Atilla, N. Cakar, and I.D. Gurhan, In vitro and in vivo investigations of the wound healing effect of crude Spirulina extract and C-phycocyanin, J. Med. Plants Res., 7, 425-433 (2013).
8. C. Caddeo, M. Chessa, A. Vassallo, R. Pons, O. Diez-Sales, A.M. Fadda and M. Manconi, Extraction, purification and nanoformulation of natural phycocyanin (from Klamath algae) for dermal and deeper soft tissue delivery, J. Biomed. Nanotechnol., 9, 1929-1938 (2013).