Abstract
Three polysaccharide-protein complexes of longan pulp (LP1-3) were isolated in this work. Their physicochemical characteristics and immunomodulatory effects on splenocytes, natural killer (NK) cells and macrophages in vitro were investigated. The carbohydrate portions of LP1-3 were principally composed of glucose, arabinose and mannose. LP3 displayed the maximal moisture absorption, and the thermal stability of LP2 was obviously higher than that of LP1 and LP3. All of them showed the characteristic polysaccharide and protein bands in the Fourier Transform Infrared (FTIR) spectrum. For a certain dose, all the fractions could significantly stimulate splenocyte proliferation, macrophage phagocytosis against neutral red, and NK cell cytotoxicity against YAC-1 lymphoma cell (P < 0.05). The results demonstrated that the polysaccharide-protein complexes of longan pulp have medical potential as immunotherapeutic adjuvants due to their immunomodulatory activities.
Highlights
The enhancement or potentiation of the host immune system has been recognized as a possible way to inhibit tumor growth without harming the host, and it is an effective long-term healthcare strategy
In order to find out more about the theoretical basis of the health-promoting effect of longan, the polysaccharide-protein complexes were first isolated from the longan pulp aqueous extract, and their physicochemical characteristics and immunomodulatory effects on murine immunocytes in vitro were investigated
Gel column chromatograms of polysaccharides and proteins in LP1-3 are shown in Figure 1, which corrresponds to the curves recorded at 490 and 280 nm, respectively
Summary
The enhancement or potentiation of the host immune system has been recognized as a possible way to inhibit tumor growth without harming the host, and it is an effective long-term healthcare strategy. As important bioactive compounds of Ganoderma lucidum, polysaccharide-protein complexes exhibit immunomodulatory and antiherpetic activities, and their mass ratios of carbohydrate/protein range from 10.4 to 28.9 [2,3,4]. The polysaccharide-protein complex of Agaricus blazei Murill can stimulate the non-specific complements and humoral immune functions via the action of polyclonal activators of B cells, inhibition of tumor growth and metastasis, and up-regulation of dendritic cell maturation [8]. The biological activity of polysaccharide-protein complex from longan (Dimocarpus longan Lour.) fruit is still not available. Zhong et al [17] have investigated the bioactivity of longan pulp polysaccharides using S180 tumor mice models. The pulp is not the part of longan fruit with the highest polysaccharide content, it is the only edible part which is widely used in traditional medicine. In order to find out more about the theoretical basis of the health-promoting effect of longan, the polysaccharide-protein complexes were first isolated from the longan pulp aqueous extract (i.e., longan polysaccharide-protein complex, LP), and their physicochemical characteristics and immunomodulatory effects on murine immunocytes in vitro were investigated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
