International Journal of Biological Macromolecules 49 (2011) 587–590 Contents lists available at ScienceDirect International Journal of Biological Macromolecules jo u r n al hom epa ge: ww w.elsevier.com/locate/ijbiomac Composition and bioactivity of polysaccharides from tea seeds obtained by water extraction Xinlin Wei 1 , Fangfang Mao 1 , Xuan Cai, Yuanfeng Wang ∗ Institute of Food Engineering, College of Life & Environment Science, Shanghai Normal University, 100 Guilin Rd, Shanghai 200234, PR China a r t i c l e i n f o Article history: Received 17 May 2011 Received in revised form 8 June 2011 Accepted 13 June 2011 Available online 17 June 2011 Keywords: Polysaccharides Tea seeds Composition Biological activities a b s t r a c t In this paper, the composition and biological activities of polysaccharides from tea seed (TSPS) obtained by water extraction were investigated. The properties and chemical compositions of TSPS were analyzed with HPGPC, IC, and IR methods. The results showed that TSPS consisted of three kinds of polysaccharides with the molecular weight of 500 kDa, 130 kDa, and 5 kDa. TSPS consisted of rhamnose, xylose, arabinose, glucose and galactose, GalA, GulA, with a molar ratio of 4.9:1.7:11.1:27.2:14.0:3.4:1, sugar backbone of TSPS might consist of glucose, but branched chain may consist of rhamnose, xylose, arabinose, and galactose. The IR spectrum of TSPS revealed the typical characteristics of polysaccharides and protein. TSPS significantly inhibited the growth of K562 cells, especially, at the concentration of 50 g/ml; the inhibition activity of TSPS was the highest with an inhibition ratio beyond 38.44 ± 2.22% (P < 0.01). TSPS with high concentrations (100, 200 and 400 g/ml) had higher proliferation effect on lymphocyte. Results of these studies demonstrated that the polysaccharide had a potential application as natural antitumor drugs. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Green tea (Camellia sinensis) has been used as the second most consumed beverage for thousands of years in the world next to water and has caused great interests among researchers [1–3]. Tea polysaccharides from different sources, such as tea flowers and tea leaves, have been found to be an important water soluble polysac- charide with certain bioactivities in the late 1980s [4–6]. Including immunostimulation [7,8], antitumor [9], antioxidant activities [10], anti-inflammatory [11], hypoglycemic activities [12], etc. All these activities are due to their contribution to enhance immune function of the human body. Tea seed polysaccharides (TSPS) are the main effective compo- nents in tea seeds, accounting for a comparative large proportion. In this study, tea seeds contained many nutrition compounds, such as protein, sugar, sucrose, vitamin, amino acid, tea polyphenols and caffeine. From this point, tea seeds are also of important application value as leaves and flowers. For a long time, however, there are very few studies about the tea seed polysaccharides (TSPS). Recently, the tea leaves polysaccharide (TPS) and tea flower polysaccharide (TFPS) has attracted great interest among researchers [13–15]. The studies and application of TSPS are also becoming valuable. ∗ Corresponding author. Tel.: +86 21 27463960. E-mail addresses: foodlab2011@gmail.com, foodlab2010@gmail.com (Y. Wang). 1 The same contribution for the first author. 2. Materials and methods 2.1. Materials and reagents Tea seeds were obtained commercially from Hubei province of China. d-Ribose (Rib), l-rhamnose (Rha), d-arabinose (Ara), l- fucose (Fuc), d-xylose (Xyl), d-mannose (Man), d-glucose (Glc), d-galactose (Gal), d-galacturonic acid (GalA) and bovine serum albumin (BSA) were purchased from Sigma (MO, USA). 1640 cell culture medium, Coomassie brilliant blue G-250 were provided from Sinopharm Chemical Reagent Co. (Shanghai, China). 3- (4,5-Dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), dimethyl sulfoxide (DMSO) were purchased from Sigma Chemical Co. All other reagents and solvents were of analytical reagent grade and used without further purification unless oth- erwise noted. All aqueous solutions were prepared using newly double distilled water. 2.2. Analytical methods of components in tea seed polysaccharides The total sugars were determined by the phenol–sulphuric acid method [16] with d-glucose as standard. The soluble protein (SP) was determined by the Coomassie brilliant blue G-250 method [17] with bovine serum albumin as a standard. Uronic acid content was determined according to a meta-hydroxydiphenyl colorimetric method [18] with galacturonic acid as standard. 0141-8130/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ijbiomac.2011.06.016