In Vitro Immunomodulation of the Polysaccharides from Yam (Dioscorea opposita Thunb.) in Response to a Selenylation of Lower Extent

Abstract

The immunomodulation of chemically selenylated polysaccharides has been attracting more attention recently, but the corresponding performance of the yam polysaccharides (YPS) with lower selenylation extent remains, thus far, unsolved. In this study, the YPS was selenylated with Na2SeO3 under acidic conditions generated by HNO3 to reach two lower selenylation extents, yielding two selenylated YPSs, namely SeYPS-1 and SeYPS-2 with selenium contents of 715 and 1545 mg/kg, respectively. The results indicated that YPS, SeYPS-1, and SeYPS-2 all had in vitro immuno-modulation when using RAW 264.7 macrophages and murine splenocytes as cell models. In detail, the three polysaccharide samples at dose levels of 5–160 μg/mL showed insignificant cytotoxicity to the macrophages and splenocytes with cell exposure times of 12–24 h, because of the measured values of cell viability larger than 100%. However, Na2SeO3 at dose levels of 1.3–3.25 μg/mL mostly caused obvious cytotoxic effects on the cells, resulting in reduced cell viability values or cell death, efficiently. The results demonstrated that, compared with YPS, both SeYPS-1 and SeYPS-2 at a lower dose level (5 μg/mL) were more active at promoting phagocytosis activity, increasing the CD4+/CD8+ ratio of the T-lymphocyte sub-population in the murine splenocyte, improving cytokine secretion, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α in the macrophages, or increasing interferon-γ secretion, but suppressing IL-4 production in the splenocytes. Consistently, SeYPS-2 has more potential than SeYPS-1 at exerting these assessed bioactivities in the cells. Thus, we conclude that a chemical modification of YPS using trace element Se at a lower selenylation extent could bring about higher immunomodulatory activity towards macrophages and splenocytes, while selenylation extent of YPS is a critical factor used to govern the assessed activity changes of YPS.

Polysaccharides in Selenium-Enriched Tea: Extraction Performance under Innovative Technologies and Antioxidant Activities

“…These results illustrate that selenium plays an important role in antioxidant activity [ 44 ]. There were positive correlations of the tea polyphenols, tea protein, uronic acid, neutral sugars, and reducing sugars with the antioxidant activities, indicating that the phenolic compounds and protein content of the Se−TPSs are also involved in the antioxidant ability, which is inconsistent with other studies [ 45 , 46 , 47 ]. Se−TPSs using PEF 2 +CE 2 showed a better antioxidant capacity, which may be related to their higher selenium content.…”

“…That is to say, the in vitro antioxidant activities of the Se−TPSs obtained using PEF 2 +CE 2 were significantly better, which was probably due to its higher selenium content, as shown in Table 1 . As reported, selenium has been demonstrated in many reports to exhibit excellent antioxidant activity [ 46 ]. However, the Se−TPSs obtained using PEF 2 +UE 2 had larger IC 50 values than CE 1 on scavenging and and the lowest T-AOC, indicating that the bioactivities of tea polysaccharides treated with PEF 2 +UE 2 were inhibited [ 35 ].…”

Polygonatum sibiricum Saponin Prevents Immune Dysfunction and Strengthens Intestinal Mucosal Barrier Function in Cyclophosphamide-Induced Immunosuppressed BALB/c Mice

“…These immune-enhancing effects could be evidenced by the changes in cytokines and immunoglobulins and increased T lymphocyte proliferation [ 16 ] and differentiation, which could be achieved through modulating pathways such as the p62/Keap1/Nrf2 pathway [ 17 ]. Currently, a variety of food and drug homologous substances have been demonstrated to exert immunomodulatory effects, such as ginseng [ 18 ], red dates, Chinese wolfberry, yams [ 19 ], and hawthorn [ 20 ].…”

Immunomodulatory Activity of Extracellular Vesicles of Kimchi-Derived Lactic Acid Bacteria (Leuconostoc mesenteroides, Latilactobacillus curvatus, and Lactiplantibacillus plantarum)

“…Macrophages play a multifunctional role in host defense, and they can limit the pathogenesis of infectious organisms and affect degenerative disease processes. Macrophages and splenocytes including T-lymphocytes, B-lymphocytes, macrophages, etc., produce various inflammatory mediators and pro-inflammatory cytokines such as nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin-1β (IL-1β), and IL-6 after activation [11,12]. Concanavalin A stimulates the proliferation of treated splenocytes (T cell mitogen), and the induced proliferation can be used as the primary model of T cell activation [13,14].…”