resumo
Longan (Dimocarpus longan Lour.) is a seasonal tropical fruit used by Chinese medicine in both fresh and dried pulp forms. Their polysaccharides have been reported to have biological activity. However, their composition and immune activity have not yet been disclosed. To fulfil this aim, hot water-soluble polysaccharides of fresh and dried longan pulp were fractionated according to their molecular weight by ultrafiltration (10, 50, 100 kDa cut off). The main polysaccharides recovered were 1,6-linked glucans branched at O-3 (4-8%), O-2 (1%), O-2,4 (0.1%), and O-3,4 (0.1%). The drying process promotes the solubility of the polysaccharides. These glucans from fresh and dried longan pulp have immunomodulatory activity, shown by in vitro phagocytosis, NO, TNF-alpha, and IL6 macrophages production assays. They showed also to inhibit the inflammatory response induced by LPS. The immunological activity of these glucans seems to have different responses dependent on their molecular weight, related to the immune regulatory pathways.
palavras-chave
IMMUNOSTIMULATORY ACTIVITY; POLYSACCHARIDES; ACTIVATION; ROOT
categoria
Chemistry, Applied; Chemistry, Organic; Polymer Science
autores
Lan, HB; Nunes, C; Lopes, GR; Wang, K; Zhao, L; Coimbra, MA; Hu, ZY
nossos autores
Cláudia Nunes
Investigador Júnior
Guido Rocha Lopes
Bolseiro de pós-DoutoramentoProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
agradecimentos
This work was supported by the earmarked fund for China Agriculture Research System (CARS-32) and the International Training for Outstanding Scientific Talents Program from South China Agricultural University (No. 2018YQGP-BS007). We gratefully acknowledge to FCT/MEC for the financial support of the Research Units CICECO (UID/CTM/50011/2019) and QOPNA (UID/QUI/00062/2019), through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. This work was also funded by national funds (OE), through FCT - Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Guido R. Lopes thanks AgroForWealth project (CENTRO-01-0145-FEDER-000001) funded by Centro2020, through FEDER and PT2020 for his post-doctoral grant (BPD/UI89/6614/2020).