Immunostimulatory Effect of Sulfated Galactans from the Green Seaweed Caulerpa cupressoides var. flabellata

Abstract

Sulfated polysaccharides (SPs) obtained from green seaweeds are structurally heterogeneous molecules with multifunctional bioactivities. In this work, two sulfated and pyruvated galactans were purified from Caulerpa cupressoides var. flabellata (named SP1 and SP2), and their immunostimulatory effect was evaluated using cultured murine macrophage cells. Both SPs equally increased the production of nitric oxide, reactive oxygen species, and the proinflammatory cytokines TNF-α and IL-6. NMR spectroscopy revealed that both galactans were composed primarily of 3)-β-d-Galp-(1→3) units. Pyruvate groups were also found, forming five-membered cyclic ketals as 4,6-O-(1’carboxy)-ethylidene-β-d-Galp residues. Some galactoses are sulfated at C-2. In addition, only SP2 showed some galactose units sulfated at C-4, indicating that sulfation at this position is not essential for the immunomodulatory activity of these galactans. Overall, the data showed that the galactans of C. cupressoides exhibited immunostimulating activity with potential therapeutic applications, which can be used in the development of new biomedical products.

Immunomodulatory Activity and Its Mechanisms of Two Polysaccharides from Poria cocos

“…As the molecular weight of the polysaccharides was higher, more repeating structures bind to receptors or membrane targets, and therefore performed considerable bioactivities [ 25 ]. Polysaccharides were capable of binding to PRRs on the surface of macrophages which activated several intracellular signaling pathways [ 26 ]. PCWPW and PCWPS with mannose and fucose residues bind to MR, exerting immunomodulatory effects by activating macrophages.…”

Bioactive Compounds, Cosmeceutical And Nutraceutical Applications of Green Seaweed Species (Chlorophyta)

“…Besides, the galactans compound extracted from C. cupressoides was also reported to possess immunostimulatory activity. It was reported that the production of nitric oxide, reactive oxygen species and proinflammatory cytokines TNF- and IL-6 were increased with the presence of C. cupressoides extracts containing galactans (Da Silva Barbosa et al, 2020). Overall, it can be deduced that various species from Chlorophyta sp.…”

A new polysaccharide from Caulerpa chemnitzia induces molecular shifts of immunomodulation on macrophages RAW264.7

“…Previous studies have displayed that Caulerpa polysaccharides have various biological activities such as C. cylindracea polysaccharide with anti-herpetic ( Magdugo et al, 2020 ) and anti-inflammatory activities ( Ribeiro et al, 2020 ), C. lentillifera polysaccharide with α-glucosidase inhibitory ( Chaiklahan, Srinorasing, Chirasuwan, Tamtin, & Bunnag, 2020 ) and antioxidant activities ( Tian, Liu, Song, Zhu, & Yin, 2021 ), C. cupressoides var. flabellate polysaccharide with immunostimulating activity ( Barbosa et al, 2020 ), and C. sertularioides polysaccharide with osteogenic activity ( Chaves, de Sousa, Viana, Rocha, de Medeiros, & Moreira, 2019 ). There is investigation on immunomodulatory effect of C. chemnitzia polysaccharides on NK cells and T lymphocytes of mice ( Shen, Wang, Guo, & Tuo, 2008 ).…”